silicone elastomers
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Silicone Elastomers
Report 137
Volume 12, Number 5, 2001
P. Jerschow
RAPRA REVIEW REPORTS
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Item 1Macromolecules
33, No.6, 21st March 2000, p.2171-83EFFECT OF THERMAL HISTORY ON THE RHEOLOGICALBEHAVIOR OF THERMOPLASTIC POLYURETHANESPil Joong Yoon; Chang Dae HanAkron,University
The effect of thermal history on the rheological behaviour of ester- andether-based commercial thermoplastic PUs (Estane 5701, 5707 and 5714from B.F.Goodrich) was investigated. It was found that the injectionmoulding temp. used for specimen preparation had a marked effect on thevariations of dynamic storage and loss moduli of specimens with timeobserved during isothermal annealing. Analysis of FTIR spectra indicatedthat variations in hydrogen bonding with time during isothermal annealingvery much resembled variations of dynamic storage modulus with timeduring isothermal annealing. Isochronal dynamic temp. sweep experimentsindicated that the thermoplastic PUs exhibited a hysteresis effect in theheating and cooling processes. It was concluded that the microphaseseparation transition or order-disorder transition in thermoplastic PUs couldnot be determined from the isochronal dynamic temp. sweep experiment.The plots of log dynamic storage modulus versus log loss modulus variedwith temp. over the entire range of temps. (110-190C) investigated. 57 refs.
GOODRICH B.F.USA
Accession no.771897
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Report 8 Engineering Thermoplastics, I.T. Barrie, Consultant.
Report 11 Communications Applications of Polymers,R. Spratling, British Telecom.
Report 12 Process Control in the Plastics Industry,R.F. Evans, Engelmann & Buckham Ancillaries.
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Report 22 Electronics Applications of Polymers, M.T.Goosey,Plessey Research (Caswell) Ltd.
Report 23 Offshore Applications of Polymers, J.W.Brockbank,Avon Industrial Polymers Ltd.
Report 24 Recent Developments in Materials for FoodPackaging, R.A. Roberts, Pira Packaging Division.
Volume 3Report 25 Foams and Blowing Agents, J.M. Methven, Cellcom
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Report 26 Polymers and Structural Composites in CivilEngineering, L. Hollaway, University of Surrey.
Report 27 Injection Moulding of Rubber, M.A. Wheelans,Consultant.
Report 28 Adhesives for Structural and EngineeringApplications, C. O’Reilly, Loctite (Ireland) Ltd.
Report 29 Polymers in Marine Applications, C.F.Britton,Corrosion Monitoring Consultancy.
Report 30 Non-destructive Testing of Polymers, W.N. Reynolds,National NDT Centre, Harwell.
Report 31 Silicone Rubbers, B.R. Trego and H.W.Winnan,Dow Corning Ltd.
Report 32 Fluoroelastomers - Properties and Applications,D. Cook and M. Lynn, 3M United Kingdom Plc and3M Belgium SA.
Report 33 Polyamides, R.S. Williams and T. Daniels,T & N Technology Ltd. and BIP Chemicals Ltd.
Report 34 Extrusion of Rubber, J.G.A. Lovegrove, NovaPetrochemicals Inc.
Report 35 Polymers in Household Electrical Goods, D.Alvey,Hotpoint Ltd.
Report 36 Developments in Additives to Meet Health andEnvironmental Concerns, M.J. Forrest, RapraTechnology Ltd.
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University of Surrey.
Report 39 Polymers in Chemically Resistant Applications,D. Cattell, Cattell Consultancy Services.
Report 41 Failure of Plastics, S. Turner, Queen Mary College.
Report 42 Polycarbonates, R. Pakull, U. Grigo, D. Freitag, BayerAG.
Report 43 Polymeric Materials from Renewable Resources,J.M. Methven, UMIST.
Report 44 Flammability and Flame Retardants in Plastics,J. Green, FMC Corp.
Report 45 Composites - Tooling and Component Processing,N.G. Brain, Tooltex.
Report 46 Quality Today in Polymer Processing, S.H. Coulson,J.A. Cousans, Exxon Chemical International Marketing.
Report 47 Chemical Analysis of Polymers, G. Lawson, LeicesterPolytechnic.
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H.T. van de Grampel, General Electric Plastics BV.
Report 50 Automotive Applications of Polymers II,A.N.A. Elliott, Consultant.
Report 51 Biomedical Applications of Polymers, C.G. Gebelein,Youngstown State University / Florida Atlantic University.
Report 52 Polymer Supported Chemical Reactions, P. Hodge,University of Manchester.
Report 53 Weathering of Polymers, S.M. Halliwell, BuildingResearch Establishment.
Report 54 Health and Safety in the Rubber Industry, A.R. Nutt,Arnold Nutt & Co. and J. Wade.
Report 55 Computer Modelling of Polymer Processing,E. Andreassen, Å. Larsen and E.L. Hinrichsen, Senter forIndustriforskning, Norway.
Report 56 Plastics in High Temperature Applications,J. Maxwell, Consultant.
Report 57 Joining of Plastics, K.W. Allen, City University.
Report 58 Physical Testing of Rubber, R.P. Brown, RapraTechnology Ltd.
Report 59 Polyimides - Materials, Processing and Applications,A.J. Kirby, Du Pont (U.K.) Ltd.
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Report 62 Coextrusion, D. Djordjevic, Klöckner ER-WE-PA GmbH.
Report 63 Conductive Polymers II, R.H. Friend, University ofCambridge, Cavendish Laboratory.
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Report 69 Toxicity of Plastics and Rubber in Fire, P.J. Fardell,Building Research Establishment, Fire Research Station.
Report 70 Acrylonitrile-Butadiene-Styrene Polymers,M.E. Adams, D.J. Buckley, R.E. Colborn, W.P. Englandand D.N. Schissel, General Electric Corporate Researchand Development Center.
Report 71 Rotational Moulding, R.J. Crawford, The Queen’sUniversity of Belfast.
Report 72 Advances in Injection Moulding, C.A. Maier,Econology Ltd.
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Report 73 Reactive Processing of Polymers, M.W.R. Brown,P.D. Coates and A.F. Johnson, IRC in Polymer Scienceand Technology, University of Bradford.
Report 74 Speciality Rubbers, J.A. Brydson.
Report 75 Plastics and the Environment, I. Boustead, BousteadConsulting Ltd.
Report 76 Polymeric Precursors for Ceramic Materials,R.C.P. Cubbon.
Report 77 Advances in Tyre Mechanics, R.A. Ridha, M. Theves,Goodyear Technical Center.
Report 78 PVC - Compounds, Processing and Applications,J.Leadbitter, J.A. Day, J.L. Ryan, Hydro Polymers Ltd.
Report 79 Rubber Compounding Ingredients - Need, Theoryand Innovation, Part I: Vulcanising Systems,Antidegradants and Particulate Fillers for GeneralPurpose Rubbers, C. Hepburn, University of Ulster.
Report 80 Anti-Corrosion Polymers: PEEK, PEKK and OtherPolyaryls, G. Pritchard, Kingston University.
Report 81 Thermoplastic Elastomers - Properties and Applications,J.A. Brydson.
Report 82 Advances in Blow Moulding Process Optimization,Andres Garcia-Rejon,Industrial Materials Institute,National Research Council Canada.
Report 83 Molecular Weight Characterisation of SyntheticPolymers, S.R. Holding and E. Meehan, RapraTechnology Ltd. and Polymer Laboratories Ltd.
Report 84 Rheology and its Role in Plastics Processing,P. Prentice, The Nottingham Trent University.
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Report 85 Ring Opening Polymerisation, N. Spassky, UniversitéPierre et Marie Curie.
Report 86 High Performance Engineering Plastics,D.J. Kemmish, Victrex Ltd.
Report 87 Rubber to Metal Bonding, B.G. Crowther, RapraTechnology Ltd.
Report 88 Plasticisers - Selection, Applications and Implications,A.S. Wilson.
Report 89 Polymer Membranes - Materials, Structures andSeparation Performance, T. deV. Naylor, The SmartChemical Company.
Report 90 Rubber Mixing, P.R. Wood.
Report 91 Recent Developments in Epoxy Resins, I. Hamerton,University of Surrey.
Report 92 Continuous Vulcanisation of Elastomer Profiles,A. Hill, Meteor Gummiwerke.
Report 93 Advances in Thermoforming, J.L. Throne, SherwoodTechnologies Inc.
Report 94 Compressive Behaviour of Composites,C. Soutis, Imperial College of Science, Technologyand Medicine.
Report 95 Thermal Analysis of Polymers, M. P. Sepe, Dickten &Masch Manufacturing Co.
Report 96 Polymeric Seals and Sealing Technology, J.A. Hickman,St Clair (Polymers) Ltd.
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Report 97 Rubber Compounding Ingredients - Need, Theoryand Innovation, Part II: Processing, Bonding, FireRetardants, C. Hepburn, University of Ulster.
Report 98 Advances in Biodegradable Polymers, G.F. Moore &S.M. Saunders, Rapra Technology Ltd.
Report 99 Recycling of Rubber, H.J. Manuel and W. Dierkes,Vredestein Rubber Recycling B.V.
Report 100 Photoinitiated Polymerisation - Theory andApplications, J.P. Fouassier, Ecole Nationale Supérieurede Chimie, Mulhouse.
Report 101 Solvent-Free Adhesives, T.E. Rolando, H.B. FullerCompany.
Report 102 Plastics in Pressure Pipes, T. Stafford, RapraTechnology Ltd.
Report 103 Gas Assisted Moulding, T.C. Pearson, Gas Injection Ltd.
Report 104 Plastics Profile Extrusion, R.J. Kent, TangramTechnology Ltd.
Report 105 Rubber Extrusion Theory and Development,B.G. Crowther.
Report 106 Properties and Applications of ElastomericPolysulfides, T.C.P. Lee, Oxford Brookes University.
Report 107 High Performance Polymer Fibres, P.R. Lewis,The Open University.
Report 108 Chemical Characterisation of Polyurethanes,M.J. Forrest, Rapra Technology Ltd.
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Report 109 Rubber Injection Moulding - A Practical Guide,J.A. Lindsay.
Report 110 Long-Term and Accelerated Ageing Tests on Rubbers,R.P. Brown, M.J. Forrest and G. Soulagnet,Rapra Technology Ltd.
Report 111 Polymer Product Failure, P.R. Lewis,The Open University.
Report 112 Polystyrene - Synthesis, Production and Applications,J.R. Wünsch, BASF AG.
Report 113 Rubber-Modified Thermoplastics, H. Keskkula,University of Texas at Austin.
Report 114 Developments in Polyacetylene - Nanopolyacetylene,V.M. Kobryanskii, Russian Academy of Sciences.
Report 115 Metallocene-Catalysed Polymerisation, W. Kaminsky,University of Hamburg.
Report 116 Compounding in Co-rotating Twin-Screw Extruders,Y. Wang, Tunghai University.
Report 117 Rapid Prototyping, Tooling and Manufacturing,R.J.M. Hague and P.E. Reeves, Edward MackenzieConsulting.
Report 118 Liquid Crystal Polymers - Synthesis, Properties andApplications, D. Coates, CRL Ltd.
Report 119 Rubbers in Contact with Food, M.J. Forrest andJ.A. Sidwell, Rapra Technology Ltd.
Report 120 Electronics Applications of Polymers II, M.T. Goosey,Shipley Ronal.
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Report 121 Polyamides as Engineering Thermoplastic Materials,I.B. Page, BIP Ltd.
Report 122 Flexible Packaging - Adhesives, Coatings andProcesses, T.E. Rolando, H.B. Fuller Company.
Report 123 Polymer Blends, L.A. Utracki, National ResearchCouncil Canada.
Report 124 Sorting of Waste Plastics for Recycling, R.D. Pascoe,University of Exeter.
Report 125 Structural Studies of Polymers by Solution NMR,H.N. Cheng, Hercules Incorporated.
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Volume 12
Report 133 Advances in Automation for Plastics InjectionMoulding, J. Mallon, Yushin Inc.
Report 134 Infrared and Raman Spectroscopy of Polymers,J.L. Koenig, Case Western Reserve University.
Report 135 Polymers in Sport and Leisure, R.P. Brown.
Report 136 Radiation Curing, R.S. Davidson, DavRad Services.
Report 137 Silicone Elastomers, P. Jerschow, Wacker-ChemieGmbH.
Report 138 Health and Safety in the Rubber Industry, N. Chaiear,Khon Kaen University.
Report 139 Rubber Analysis - Polymers, Compounds andProducts, M.J. Forrest, Rapra Technology Ltd.
Report 126 Composites for Automotive Applications, C.D. Rudd,University of Nottingham.
Report 127 Polymers in Medical Applications, B.J. Lambert andF.-W. Tang, Guidant Corp., and W.J. Rogers, Consultant.
Report 128 Solid State NMR of Polymers, P.A. Mirau,Lucent Technologies.
Report 129 Failure of Polymer Products Due to Photo-oxidation,D.C. Wright.
Report 130 Failure of Polymer Products Due to Chemical Attack,D.C. Wright.
Report 131 Failure of Polymer Products Due to Thermo-oxidation,D.C. Wright.
Report 132 Stabilisers for Polyolefins, C. Kröhnke and F. Werner,Clariant Huningue SA.
Silicone Elastomers
ISBN: 1-85957-297-9
Peter Jerschow
(Wacker-Chemie GmbH)
Silicone Elastomers
1
Contents
1. Introduction .............................................................................................................................................. 5
1.1 Nomenclature ....................................................................................................................................... 5
2. Silicone Elastomers Market .................................................................................................................... 6
3. Applications for Silicone Elastomers ..................................................................................................... 7
3.1 Automotive ..................................................................................................................................... 7
3.2 Healthcare and Medical .................................................................................................................. 9
3.3 Wire and Cable ..............................................................................................................................11
3.4 Sanitary, Household and Leisure .................................................................................................. 13
3.5 Transmission and Distribution ...................................................................................................... 16
3.6 Electronics .................................................................................................................................... 17
3.7 Mould Making .............................................................................................................................. 20
3.8 Food Sector ................................................................................................................................... 21
3.9 Other ............................................................................................................................................. 23
3.9.1 Safety Applications ........................................................................................................... 233.9.2 Aerospace ......................................................................................................................... 243.9.3 Building Industry .............................................................................................................. 243.9.4 Pharmaceutical ................................................................................................................. 243.9.5 Spin Casting...................................................................................................................... 24
4. Composition and Function of Silicone Elastomers ............................................................................. 25
4.1 Introduction and Classifications ................................................................................................... 25
4.2 Properties of Silicone Elastomers ................................................................................................. 25
4.3 Chemistry and Curing Mechanisms of Silicone Elastomers ........................................................ 26
5. Room Temperature Vulcanising Silicone Elastomers ........................................................................ 27
5.1 General .......................................................................................................................................... 27
5.2 Condensation Curing RTVs .......................................................................................................... 28
5.3 RTV-1 for CIPG and FIPG ........................................................................................................... 28
5.4 RTV-1 for Baking Tray Coatings .................................................................................................. 29
5.5 Adhesive RTV-1 Materials ........................................................................................................... 29
5.6 Condensation Curing RTV-2 Systems .......................................................................................... 31
5.7 Mould Making Condensation Curing RTV-2 Materials ............................................................... 31
5.7.1 Speciality Mould Making RTV-2 Materials ..................................................................... 32
5.8 Condensation Curing RTV-2 Compounds for Encapsulation ...................................................... 32
5.9 Adhesives and Sealants Based on Condensation Curing RTV-2 Compounds ............................. 33
5.10 Addition Curing RTV-2 Systems .................................................................................................. 33
Silicone Elastomers
2
5.11 Silicone Gels ................................................................................................................................. 34
5.12 Addition Curing Systems for Mould Making ............................................................................... 35
5.13 Addition Cured RTV-2 Systems for Encapsulation ...................................................................... 35
5.14 Addition Cured RTV-2 Adhesives and Sealants ........................................................................... 36
5.15 Addition Cured RTV-2 Foam for Compressible Gaskets ............................................................. 36
6. Liquid Silicone Rubber ......................................................................................................................... 37
6.1 General .......................................................................................................................................... 37
6.2 Curing Mechanism of Liquid Silicone Rubbers ........................................................................... 37
6.3 Standard Liquid Silicone Rubbers ................................................................................................ 38
6.4 Speciality LRs ............................................................................................................................... 39
6.4.1 High Tear LR .................................................................................................................... 396.4.2 No Post Cure LR .............................................................................................................. 396.4.3 Heat Stabilised LR............................................................................................................ 406.4.4 Coolant Resistant LR (NPC) ............................................................................................ 416.4.5 Self Lubricating LR (NPC) .............................................................................................. 416.4.6 Oil Resistant LR (NPC) .................................................................................................... 426.4.7 Self Adhesive LR.............................................................................................................. 426.4.8 Electrically Conductive (Antistatic Silicone!) LR ........................................................... 466.4.9 Flame Retardant LR ......................................................................................................... 466.4.10 Extra Liquid Rubber (XLR®) ........................................................................................... 476.4.11 Other Types of LR ............................................................................................................ 47
6.5 Pigment Pastes .............................................................................................................................. 47
7. Solid Silicone Rubber ............................................................................................................................ 47
7.1 General .......................................................................................................................................... 47
7.2 Curing Mechanisms of Solid Silicone Rubbers ............................................................................ 48
7.2.1 Addition Cure ................................................................................................................... 487.2.2 Peroxide Cure ................................................................................................................... 49
7.3 Standard Solid Silicone Rubbers .................................................................................................. 49
7.4 Speciality HTV (all peroxide) ...................................................................................................... 50
7.4.1 High Tear HTV ................................................................................................................. 507.4.2 Economy High Tear HTV ................................................................................................ 507.4.3 Extrusion HTV ................................................................................................................. 507.4.4 Cable HTV........................................................................................................................ 507.4.5 Oil Resistant HTV (NPC)................................................................................................. 507.4.6 Electrically Conductive HTV ........................................................................................... 517.4.7 Super Heat Stable HTV .................................................................................................... 517.4.8 High Green Strength/Coolant Resistant HTV .................................................................. 527.4.9 Steam Resistant HTV ....................................................................................................... 527.4.10 Heat Conductive HTV ...................................................................................................... 527.4.11 HTV for Transmission and Distribution (T&D) Applications ......................................... 53
7.5 Addition Cured HTV .................................................................................................................... 53
7.5.1 Introduction ...................................................................................................................... 537.5.2 Addition Curing ................................................................................................................ 53
Silicone Elastomers
3
The views and opinions expressed by authors in Rapra Review Reports do not necessarily reflect those ofRapra Technology Limited or the editor. The series is published on the basis that no responsibility orliability of any nature shall attach to Rapra Technology Limited arising out of or in connection with anyutilisation in any form of any material contained therein.
7.5.3 Moulding: 1K Addition Cured HTV ................................................................................ 547.5.4 Moulding: 1K Self Adhesive Addition Cured HTV......................................................... 557.5.5 Moulding: 2K Addition Cured HTV ................................................................................ 557.5.6 Extrusion HTV ................................................................................................................. 567.5.7 Post Curing of Addition Cured HTV ............................................................................... 56
8. Processing Silicone Elastomers ............................................................................................................ 56
8.1 RTV-1 Systems ............................................................................................................................. 56
8.2 RTV-2 Systems ............................................................................................................................. 56
8.2.1 Mould Making: Flexible Moulds ..................................................................................... 578.2.2 Mould Making: Block Moulds ......................................................................................... 588.2.3 Mould Making: Skin Moulds ........................................................................................... 58
8.3 LR and HTV ................................................................................................................................. 58
8.3.1 Press Curing HTV ............................................................................................................ 588.3.2 Transfer Moulding HTV................................................................................................... 588.3.3 Injection Moulding LR and HTV ..................................................................................... 598.3.4 Extrusion of HTV ............................................................................................................. 628.3.5 Moulding HTV (General) ................................................................................................. 628.3.6 Calendering HTV ............................................................................................................. 638.3.7 Rollers ............................................................................................................................... 648.3.8 Bonding ............................................................................................................................ 64
9. Summary ................................................................................................................................................ 64
Additional References ................................................................................................................................... 65
Abbreviations and Acronyms ....................................................................................................................... 65
References from the Rapra Abstracts Database .............................................................................................. 67
Subject Index ....................................................................................................................................................... 153
Silicone Elastomers
4
Silicone Elastomers
5
1 Introduction
Silicone elastomers are elastic substances whichcontain linear silicone polymers crosslinked in a 3-dimensional network.
In most cases this network also contains a filler whichacts as a reinforcing agent or as an additive for certainmechanical, chemical or physical properties.
In general all silicones (usually we refer to silicones aspolydimethyl siloxanes) are noted for their high thermalstability, biocompatibility, hydrophobic nature,electrical and release properties. When silicones arecrosslinked to form a silicone rubber their characteristicproperties are still prevalent. Hence silicone elastomerscan be widely used in a great variety of applications.Some examples are shown in Table 1. These will bedescribed in more detail when concentrating on specificgroups of materials and applications.
We will not refer too much to silicone adhesives inthis article, in spite of the fact that they form siliconeelastomers when being cured. These materials havebeen referred to extensively in the literature (a.1, a.2).
1.1 Nomenclature
The nomenclature classifies silicone elastomers by theircuring mechanism and curing conditions. Siliconerubbers are essentially divided into two groups ofmaterials, i.e., room temperature vulcanising (RTV) andhigh temperature vulcanising (HTV). RTV systems areable to cure at room temperature and HTV systems attemperatures well above 100 °C. A number in the nameindicates the number of components that upon mixingwill form a curable composition, e.g., RTV-2.
HTV rubbers are mainly so-called solid silicone rubbers.They have a very high viscosity in the uncured state andappear as solids. This behaviour has also led to thecreation of the term ‘High Consistency Rubber’ (HCR).
Approximately 25 years ago a new group of materialsappeared that was intended for processing in injectionmoulding machines. Because of their low viscosity andpaste-like behaviour they were named liquid siliconerubbers (LSR) or simply liquid rubbers (LR). It iscommon to use LSR or LR as an abbreviation insteadof HTV, even though they vulcanise at hightemperatures as in the case of solid silicone rubbers.
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Silicone Elastomers
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For the most part all LR materials are 2 componentsystems which cure after mixing and at elevatedtemperatures.
In summary the silicone industry uses the terms RTV-1, RTV-2, LR or LSR, HTV or HCR. These refer to thematerial categories as follows:
RTV-1 Room temperature vulcanising, onecomponent
RTV-2 Room temperature vulcanising, twocomponent
HTV High temperature vulcanising, solidsilicone rubber, high consistency rubber
LR Liquid rubber, liquid silicone rubber (whichis also cured at high temperatures).
In this article I will concentrate on applications,requirements and materials and why to choose siliconeelastomers in the cases discussed.
The second half of this review will concentrate on thevarious types of silicone elastomers, their chemistryand processing.
2 Silicone Elastomers Market
In 1999 the global market consumed approximately170,000 tons of silicone elastomers.
Figure 1 shows the market shares between the materialcategories. Among all silicone elastomers LR exhibitsthe highest growth rate and HTV has the highest portionof the market.
Silicone Elastomers
7
Figure 1
Silicone elastomers world market by materialcategories
3 Applications for Silicone Elastomers
3.1 Automotive
Table 2 provides a rough overview of the most commonautomotive applications for silicone elastomers andindicates suitable silicone elastomers.
The specific requirements of car builders and theirsystem suppliers have made silicone elastomers anindispensable raw material for automotive components.
One should also mention that silicone fluids, fumedsilica, tyre release agents, paint additives, siliconepolish and resins are as indispensable for carcomponents as silicone elastomers.
The key reasons for the consumption of silicones inautomotive applications are numerous.
Heat resistance, cold flexibility, oil and chemicalresistance mainly account for the use of silicones inthe engine and areas close to the engine.
Long-term properties such as ‘infinite’ flexibility andlow compression set make silicones the perfect choicefor airbag coatings, gaskets, bellows, profiles, etc.
Very high dielectric strength and surface resistance, andhydrophobic behaviour are required in electricinstallations for cars. This, however, holds for most wireand cable applications. Apart from being ‘perfect’electrical insulators, silicone elastomers can be modifiedto become electrically conductive parts which are then
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scinortcelednareggirtgabriA X X X
swolleB X X
…deunitnoc
Silicone Elastomers
8
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Silicone Elastomers
9
used, for example, in parts for the ignition system (suchas the ignition cable inner lead and spark plugs).
The dielectric and other properties make them suitablefor spark plug boots and encapsulation of electroniccomponents (even safety components such as airbagand ABS controls).
Any application related to the car body is subjected tomost of the property requirements already mentioned.UV stability is another predominant requirement forparts used in such applications.
The term ‘stability’ means that a material will notimmediately or slowly change its properties over timeon exposure to a certain condition. In other words, agiven mechanical and/or chemical parameter shouldchange as little as possible. In most casesspecifications include relative changes over time(changes in percentage of a property value comparedto the initial values). Property requirements forautomotive applications are shown in Table 3.
3.2 Healthcare and Medical
Table 4 provides a rough overview of the most commonapplications and suitable silicone elastomers in medicaldevices, healthcare applications and related areas.
The field of applications for silicone elastomers is aswide in medical applications as in the automotivesector. Furthermore this is a growing sector, becauseof the substitution of other organic elastomers, such aslatex, and thermoplastics, such as PVC.
Reportedly silicone elastomers have often beendiscussed as the ideal material for medical devices andapplications. This also includes the genetics,biotechnology and pharmaceutical industries.
The main reason for this great interest in silicone rubberis due to its biocompatibility. For example, siliconerubbers show:
NO pyrogenicity (NO body temperature reaction),NO haemolysis (NO red blood cell destruction) andNO cytotoxicity (do not affect live cells).
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sretehtaC X X X
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Silicone Elastomers
10
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Thus correctly produced and treated silicone partsmade out of selected materials suitable for medicaldevices will pass tests according to ISO10993 andUS Pharmacopoeia Class VI, EuropeanPharmacopoeia and other protocols.
Figure 2 shows certificates from test laboratoriesas obtained on the biocompatibili ty ofELASTOSIL® R4110/60 and 4305/40, siliconeelastomers produced by Wacker.
The key reasons for the consumption of silicones inmedical/pharmaceutical devices and equipment are:biocompatibility, gamma ray resistance, chemicalresistance, sterilisability (gamma ray, ethylene oxide(EtO), steam), pigmentability, transparency,durability, and the fact that they are non allergenic.
In addition, all the properties mentioned under theautomotive section (3.1) also complement their
competitive advantages compared to other organicelastomers.
As many medical devices must be manufacturedunder special hygienic conditions, in compliancewith Good Manufacturing Practice (GMP), incleanrooms, silicones seem to be a good choice ofmaterials as well.
In many cases they can be processed almost withoutforming any reaction products, which might impairpurity, smell or sterility of the manufactured goods.
Silicones are not only bioinert, their excellentelectrical insulating properties make them a usefulcomponent of any medical equipment, be it sensoric,or for resuscitation, etc. This is also supported by theirhydrophobic behaviour, which prevents them fromaccumulating moisture from the surroundingenvironment.
Silicone Elastomers
11
Table 5 summarises most of the mentioned propertiesas they relate to areas where medical devices are mostcommonly used.
Summing up we can draw the conclusion thatsilicones have a great future in medical devicetechnology. However, their reputation as long-termimplants has been sullied after the bad press and thevast number of lawsuits with respect to siliconebreast implants.
In order to support the duty of care of suppliers to themedical device industry, in most cases siliconemanufacturers have set internal healthcare guidelines.Basically these list allowed applications for each
material and those that are not supported by the siliconemanufacturer. As a general rule, many siliconemanufacturers restrict their supply to this industry toshort-term implants. In other words, the providers ofsilicone elastomers will not usually support implantsor devices involving permanent body contact (longerthan 29 days).
3.3 Wire and Cable
Silicone rubbers are used for applying an electricallyinsulating layer onto the conductive thread of a cable.
Many of these insulations are made of HTV siliconerubber.
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Figure 2
Certificates on the biocompatibility of ELASTOSIL® R4110/60 and 4305/40
Silicone Elastomers
12
Increasingly, the latest development, i.e., pelletisedsilicone rubber is being used in such applications.Existing and innovative applications are shown inTable 6.
The specific requirements for silicone elastomers thatare used in cables develop from the requirements ofcable manufacturers and their end users.
As to manufacturers in particular, the silicone rubbermust be easily extrudable in order to allow outputs ofup to 400 m/min of ready made cable.
Typically cable insulations made of HTV will exhibita dielectric strength of 18-20 kV/mm and a volumeresistivity of 1015 Ωcm.
End users often specify their cables to comply withinternational and national standards, such as the VDEstandards. The most important requirement for thesilicone in this application is the heat resistance. TheVDE standard, VDE 0303, specifies an elongation atbreak of >200% after heat ageing for 10 days at200 °C.
The use of silicone rather than PVC or otherthermoplastic and elastomer materials, has beenboosted by safety discussions after recent fire accidentsin which most of the damage was unfavourablyattributed to the contribution of the PVC sleevings tosmoke toxicity and density and cable function. Silicone
cables burn at a much slower speed and theircombustion products have low toxicity.
During combustion silicone degrades to silica. Hence,most of the silicone forms an electrically insulatingash. This prevents short circuits and theirconsequences.
The accidents referred to above gave rise to the rapiddevelopment of so-called safety cables. Such cableswill maintain the integrity of the electric circuit overa certain period of time in the case of a fire. Usingspecial silicone grades, such as ELASTOSIL® R 502/75 from Wacker Chemie GmbH, enables cablemanufacturers to produce a safety cable which willmaintain circuit integrity over 90 minutes attemperatures higher than 1,000 °C even if they arequenched with water. This technology is based on thefact that ceramics are electrical insulators.ELASTOSIL® R 502/75 turns into a ceramic when itis being burned. It goes without saying that the safetyof such cables is also a question of design.
Very recent developments have led to addition curedsafety cable compounds and compounds which forman even harder ceramic. These are summarised inTable 7 (a.3).
A further competitive advantage of these safety cablematerials is the fact that they can be extruded at veryhigh speeds (of up to 400 m/min) whereas more
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selbactnatsiserraeW X X X X
selbactnemurtsnI X X
selbacyrettaB X X
selbaclangisytefaS X X
selbacrewopytefaS X X
selbacedargymonocE X X
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Silicone Elastomers
13
traditional safety cable technology allows only a fewmetres per minute. For example, mica tape safety cableshave a production rate of 12 m/minute.
Table 8 summarises most of the properties of siliconesrelevant to wire and cable applications.
Over the past years the cable markets have degeneratedinto a commodity business. In most cases the costpressure on industries related to consumer electronics,household appliances and car manufacturers was toohigh to maintain this as a speciality area.
Some cable markets were dominated by siliconerubbers that were heavily filled with quartz in orderto bring the cost down (silicone suppliers call this‘elastic stone’).
Today, cable manufacturers are in a renaissance as therequirements have changed. The safety and high qualityaspect seems to have gained priority over plain costcalculations.
Recently developed new technologies such assilicone rubber pellets, safety cable grades and wearresistant cables have also led to new applicationareas for silicone rubbers/elastomers used as cableinsulation material.
3.4 Sanitary, Household and Leisure
Apart from wires and cables described under theprevious chapter, sanitary and household appliancesutilise silicones in tap water equipment and domesticappliances.
Table 9 provides a rough overview of commonapplications and suitable silicone elastomers.
The consumption of silicones and, in particular, siliconeelastomers in household appliances and related areassuch as sanitary, gardening, agricultural and leisureequipment is enormous. The growth of suchapplications is often due to the substitution of otherorganic elastomers, such as EPDM and thermoplasticelastomers, etc.
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Silicone Elastomers
14
In most cases the properties of silicone elastomersare more favourable than those of organic rubbers.Silicone elastomers allow a high degree ofautomation in processing. However, material costsare relatively high and cost is an important factor inthis application area.
As in most applications in this field mass production isprevalent, annual production is usually 100,000 or morepieces, hence the processing advantages of siliconerubber can drastically improve the cost structure.
In other words, when processing an elastomer the costof the ready made piece often depends on the processingcost per piece rather than the cost of the materialconsumed per piece.
Any difference in material cost between siliconeelastomers and other rubbers/elastomers is deceptivetherefore, because it does not indicate the differencesin the specific complexity and duration ofprocessing.
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sgnittifrofteksagretawpaT X
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sroodenihcamgnihsawrofteksaG X X
senihcamgnihsawnisrepmadnoitarbiV X X
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)seliforp(slaesroodnevO X
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snoitacilppaytefaS X X X
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tnempiuqegniviD X X
Silicone Elastomers
15
In many cases silicone elastomers are processed withoutany major secondary operations. It is also possible toeliminate any manual steps in production. Theconsequence is a much higher accuracy and consistencyof the production process and substantial cost savings.
Silicone rubbers, when processed and post curedcorrectly do not usually affect the taste of thesurrounding media. Other properties such as lack ofcytotoxicity have been discussed in Section 3.2; thussilicone rubber is useful for tap water equipment.
In comparison to organic rubbers, silicone elastomersdo not contain any harmful substances such asnitrosamines. The nitrosamine level in silicones isbelow detection level or below the common limit of10 ppb after correct processing. The levels ofnitrosamines are higher in some organic rubbers. Theirorigin is thought to be in the curing system whichcontains amines. As a consequence, apart from theeffect on smell and taste, nitrosamines remain in therubber (a significant proportion are non volatile, andthus would not evaporate over time).
In drinking water applications a number of internationaland national regulations apply, administered by: The
National Sanitation Foundation (NSF) in the US, WaterRegulations Advisory Scheme (WRAS) in the UK, andthe KTW guidelines in Germany, etc.
Silicones are suitable for most of these standards.Producers of raw materials usually have a number ofsuitable materials with a KTW or WRAS certificate.
These certificates also include colours, as shown inFigure 3. Even though many materials are containedin such certificates, the end seller will have to producea separate approval certificate for his own system.
In this area of applications design aspects are ofimportance, such as pigmentability and transparency.
Further, compared to other plastics or rubbers, standardsilicones will produce no toxic gases and low smokedensity should they burn. Additionally, standardsilicones will have lower inflammability than organicrubbers. Thus, all silicone rubbers would pass a UL94HB flame test (a.4). Special additives can be used toincrease this further, resulting even in UL94 V0 ratings.
Table 10 summarises most of the properties of siliconeelastomers related to household and similar areas.
Figure 3
WRAS and KTW certificates (reproduced with permission)
Silicone Elastomers
16
3.5 Transmission and Distribution
These applications cover the transmission and distributionof electric power. Special silicones are the best choice formedium and high voltage cable accessories and insulatorsas described below.
Historically, the transmission and distributionapplications for silicones developed from normalporcelain insulators which were covered with siliconegrease in order to achieve hydrophobicity. Later,silicone rubber dispersions were used to cover porcelainwith a rubbery and hydrophobic layer.
Today, after 30 years of development, insulators tendto consist entirely of special silicone rubbers. Most ofthem contain special fillers allowing for more enhancedelectrical properties.
The technology of silicone rubber pellets is also availablefor these special grades resulting in processing advantages.
For performance reasons silicones are increasinglyused in these areas as ceramics and organic rubbersdo not show the same degree of performance,particularly in medium and high voltageapplications. Table 11 gives a list of key applicationsand the silicone elastomer type used.
Even though the number of applications listed in theabove table is seemingly quite small therequirements are various and the scope of theseapplications is enormous.
The most important properties are based on theelectrical parameters of silicone rubbers, such asdielectric strength (around 18-20 kV/mm), volumeresistivity (1015 Ωcm) and surface resistance(1013 Ω). As yet mentioned under earlier chaptersthese properties are the reason for the suitability ofsilicone rubbers for electrical applications.
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Silicone Elastomers
17
A further asset of silicones is their hydrophobicbehaviour which is of importance in many outdoortransmission and distribution applications. As a resultof their hydrophobic nature, silicone insulators showmuch smaller leakage currents than porcelain or EPDMoffsets. Even in cases of high contamination (even ifconductive!) silicone insulators will remainhydrophobic along their surface. Silicone elastomersare capable of turning deposits from their environment(such as dust, sea salt, etc.) hydrophobic. This is dueto the small amount of siloxanes bleeding out of theelastomer surface, covering the deposit and renderingit hydrophobic.
Even after cleaning the insulators with detergents thehydrophobic behaviour will remain or return in duecourse. This is called hydrophobic transfer andregeneration.
Insulators in outdoor applications often are in contactwith moisture. This is why tracking resistance is ofutmost importance, silicone rubbers for these situationshave tracking resistance >2.5kV. (Special siliconegrades provide a tracking resistance of ≥4kV.)
Should flashovers take place special silicone elastomersalso exhibit excellent resistance to electric arcs.
Needless to say, as silicone elastomers have relativelylow changes of properties over time and temperaturethey are very suitable for long-term applications and forvarying conditions. Silicone elastomer insulators canresist temperatures down to –45 °C, remaining flexible.
UV and ozone resistance complement the spectrumof properties.
Table 12 summarises the properties required fordifferent application areas, where specialty siliconerubbers are used in the transmission and distributionindustries.
Long life, resistance to severe conditions and otherproperties make silicone elastomers suitable materialfor electric insulators in transmission and distributionapplications. This is particularly of importance whereelectric energy must be distributed in desert or coastalareas, where the most severe conditions occur.
3.6 Electronics
Silicone elastomers are highly rated materials forelectronic components. Their main use is encapsulationand in composites, as summarised in Table 13. Manyapplications in this sector can also be referred to ashousehold, automotive, consumer, etc., applications.However, they are dealt with in this section as theirmain purpose is to protect and/or allow the performanceof electronic components.
HTV, LR or RTV-1 silicones are only used in a fewcases. This has to do with the fact that electroniccomponents are too sensitive chemically for RTV-1 andmechanically for LR or HTV to allow for their use(Table 13).
For encapsulation of electronic components, potableRTV-2 systems provide the best solution. Typically, theyare transparent or opaque and exhibit low viscosities orthixotropic behaviour. Their pot life is long and theircuring time is very short, in particular after slight heatingof the mix. In order to provide maximum performancewith respect to electrical properties and corrosivebehaviour their ion content is very low. Special systemswill perform well down to –100 °C. As to vibrations,shocks, etc., they provide maximum mechanicalprotection of the encapsulated electronic system due totheir mechanical damping properties.
One of the most popular electronic applications in theautomotive sector are so-called weather packs. Theseare described in Section 6.4.5 of this review. In mostcases one would use oil exuding LR.
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Silicone Elastomers
18
Maximum reliability is crucial in safety applicationssuch as ABS and airbag control or medical electronicequipment, for instance.
This requires optimum adhesion to circuit boards andhousing, low modulus (thus high flexibility) and theabsence of solvents, the latter is also required forenvironmental compatibility.
Some applications require very high thermalconductivity (to allow for the transfer of heat), materialsup to 2.0 W/mK are used for such applications. Forexample, thermal conductivity is a must for sensoricequipment, e.g., for temperature measurement.
As mentioned earlier silicones are excellent electricalinsulators. This, their mechanical properties and theirhydrophobic character make them suitable forelectronics.
Needless to say, easy processing is a must. This allowsfor high output rates in processing and a good degreeof flexibility.
A good example of a consumer electronic applicationare anode caps for TV sets. Typically, they would alsobe part of electroencephalogram (EEG),electrocardiogram (ECG) and related equipment, andall applications requiring high voltage such as in thecase of anodes of tubes for TV screens. Therequirements are very high dielectric strength, flameand heat resistance. As anode caps, safety switches,etc., originate from moulding processes, it is alsorequired that the curing times be very short.
Table 14 shows inflammability ratings and limitingoxygen indices of various liquid silicone rubbers andHTVs including the Underwriters’ Laboratory (UL)classifications (a.4).
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Silicone Elastomers
19
Materials for electronic key pads require utmostdurability (number of cycles of pressed keys), very highresistivity and pigmentability. Most key pads are alsopainted and/or printed with special inks. Good adhesionof such inks complements the requirements. Specialink formulations provide excellent adhesion and wearresistance. They are, of course, silicone based.
Cellular phones, radios and electronic controls oftenwork with electromagnetic signals. In order to shieldtheir electronic interior one has to use special housings.These housings are sealed with gaskets which act asan electromagnetic shield. As with all gaskets they haveto be elastic over a wide range of conditions. Thus,silicone is the best choice. Special silicones areequipped with highly conductive additives that allowfor sufficient shielding. Rapid curing and adhesiveproperties are further complementing properties. Thesilicone elastomers are applied by robots onto plasticframes and/or housing.
Special silicone elastomers are also applied in themanufacture of electronic chips and for solar cells inaerospace applications. This implies UV stability,resistance against irradiation, low volatiles andoptimum adhesion.
Such properties allow their use in power modules suchas components of rectifiers, welding equipment,elevators, etc.
Optocouplers often contain RTV-2 silicone gelsbecause of their high transparency. Such gels can bemade thixotropic by certain additives which allowspartial coverage. Good electrical properties andinsensitivity to thermomechanical stress andtemperature changes complement the advantages ofthe use of silicone gels.
One of the most important properties of siliconeelastomers in electronics is long-term integrity. Thisallows for their use in long lasting sensors andencapsulated circuit boards.
Apart from the minor part of applications in electronicsthat are produced by injection moulding such as anodecaps (with the exception of weather packs), most ofthe products are produced by using potting technology.
As this technology refers to electronics for the mostpart it will be described briefly.
Potting is a technology that is used in order to protectelectronic devices. Fully automatic processing involvessingle or multicomponent mixing and meteringequipment. This apparatus is usually part of a massproduction process. Silicone elastomers in use here aredesigned for simple mixing ratios and the individualcomponents in most cases have viscosities of the sameorder of magnitude. Fully automatic and highlyaccurate application techniques have evolved.
Potting is used in covering chips, hybrid circuits, powermodules and other devices.
RTV-1 and RTV-2 UV curing systems are known aswell as HTV, 1- and 2-component materials.
Potting compounds can be very soft and flexible, butalso rigid or highly elastic. Soft gels are recommendedfor covering highly sensitive components. Pottingsystems can be:
• low viscosity or thixotropic
• highly transparent
• flame retardant
• thermally conductive
• fuel resistant
• cold resistant
• resistant against thermal shock
• low shrinkage
• adhesive to plastics
• low volatile (low outgassing)
• good damping properties.
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Silicone Elastomers
20
Table 15 summarises most of the properties requiredfor applications in electronics.
3.7 Mould Making
Whenever I mention mould making in conjunctionwith RTV materials or in the present chapter, I donot mean the construction of moulds for injectionor press moulding, as required for the processing ofLR and HTV.
Silicone elastomers are used in the production offlexible moulds for pourable, spreadable or paste-like materials which solidify in certain conditionsand subsequently lead to variously shaped products.Some of these applications might also be describedas household, automotive, consumer, semiconductor,etc. However, they differ from the previous sectionsbecause the silicone is used to make parts of adifferent material which is not necessarilyelastomeric.
All mould making materials are limited to RTV-2systems. A distinction is made between condensationand addition curing systems. This is based on thereaction mechanisms of the two systems.
Table 16 describes the applications of siliconeelastomers in mould making.
The main intention of mould making in theseapplications is quick and simple reproduction ofcertain shapes. This is the case if one wants to copya unique original, to duplicate a master copy, or aprototype, or to repair damage.
As each mouldable material has its specificcharacteristics, the range of available mouldmaterials is broad.
The biggest requirement for a mould making materialis chemical resistance, as the chemical nature of mostmouldable materials is at least slightly aggressiveunder moulding conditions. Chemical resistance ischaracterised by the change of a certain property overtime. If this change is relatively small, the mouldmaking material will allow a very high number ofmoulding cycles. This number would obviously belowered drastically as a consequence of, e.g.,premature embrittlement, which can be caused byexcessive heat. This would be the case if one uses anorganic rubber with relatively low heat resistancecompared to silicone.
Flexibility is possibly the second most importantproperty of silicone elastomers in mould making.
The mould should be capable of accuratelyreproducing the surface details of the original design.However, at the same time it must allow for optimumrelease properties. Silicone elastomers have a uniquechemical structure, which is responsible for suchrelease properties (as a result of the highlyhydrophobic nature).
Block moulds are produced by pouring or impressiontechniques. This is mainly done if one has to copyonly one side of the original, and it will allow onlyfor ‘shallow’ undercuts. Small models with simpleundercuts are made from block moulds of two or moreparts by pouring or impression.
Copying deeper undercuts requires skin moulds asobtained by spreading, dipping or pouring. Suchmoulds need a rigid mechanical support, such as plasteror laminate. If undercuts become more complicated onewill use a skin mould of two or more parts (using aspreading technique for bigger upright objects).
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Silicone Elastomers
21
Reproduction materials suitable for use in siliconemoulds are:
• Plaster, cement, concrete, synthetic stone or ceramics
• Waxes
• Casting resins such as polyesters, polyurethaneresins and foams, epoxy resins and, within limits,acrylic resins
• Low-melting metal alloys (melting points below350 °C).
3.8 Food Sector
The reader may have guessed from the use of siliconeelastomers in medical device technology that they arealso suitable for use in contact with food. This is,
indeed, true. The reasons are in the compatibility ofsilicones with their environment, chemical resistance,physical and mechanical properties.
Table 17 provides an overview over food and relatedapplications. Silicone elastomers are used in manydifferent areas ranging from packaging aids or elementsto tubings for the food industry.
This section is somewhat related to Section 3.4, on theuse of silicone in contact with drinking water. However,here we concentrate on applications where siliconerubbers are directly in contact with foodstuffs.
Important baby care applications are included in thischapter as baby feeding equipment is one of the largerapplications for liquid silicone rubbers.
Silicone elastomers in contact with foodstuffs have tocomply with relevant legislation and regulations.
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Silicone Elastomers
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Perhaps the most famous regulations in that respectare the German BgVV Recommendation XV‘Silicones’ and the US Food and DrugAdministration (FDA) Regulation CFR21 Section177.2600. These contain positive lists of sanctionedingredients for rubber parts in contact with food.What is not listed must not be contained in thesilicone elastomer formulation. BgVV also regulatesthe amount of volatile matter in the siliconeelastomer. The weight loss of a silicone part mustnot exceed 0.5% after heat treatment for 4 hours at200 °C. Further, the two regulations prescribeacceptable levels of extractables, etc.
Silicone elastomers meet such requirements, if they areprocessed correctly and have undergone sufficient postcure. Post curing is used in order to finalisevulcanisation and strip off volatiles which are containedin the rubbers as cured. The loss of volatiles from asilicone elastomer during post cure is illustrated inFigure 4, using different thicknesses of samples anddifferent temperatures.
Further, post curing also helps to improve physical andchemical properties, such as the compression set. Thisis shown in Figure 5.
In the case of baby care applications, which were oncedominated by latex, silicone elastomers are becomingmore and more prevalent. This has to do with the factthat the curing systems of organic elastomers ofteninclude amines and other additives leading to potentialtoxic contaminants, such as nitrosamines.
On the other hand there are silicone rubbers/elastomerswhich are amine free and, in most cases, are platinumcured. Such curing systems allow for biocompatibility,as mentioned in the healthcare chapter. Correctlyprocessed parts do not show detectable nitrosaminelevels without and after proper post cure.
Other favourable properties of silicone elastomers forfood contact are sterilisability, steam, heat and chemicalresistance which makes them the perfect materials inbaking moulds, baking tray coatings and the like.Typically, silicone baking moulds are produced fromliquid silicone rubber or addition cured HTV.
The silicone rubber has the required heat and chemicalresistance. Well established companies specialising inconsumer goods and appliances have started to sellthese products including life time guarantees andspecial cooking advice.
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Silicone Elastomers
23
The food industry is using silicone elastomers fortubings and fittings. Perhaps one of the most interestingapplications in the rubber industry related to food ismilking equipment. Predominantly this area has beenoccupied by nitrile rubbers, which again use potentiallyunfavourable additives. In the last 5 years siliconeelastomers have begun to be substituted in thisapplication. The parts are limited to silicone tubing,milking teats and milk liners. Reportedly, they exhibita longer life time and are quasi inert with respect tomigratable substances in line with the regulations (againproper processing and post curing are a must).
3.9 Other
3.9.1 Safety Applications
The most valuable safety property is the fact thatsilicone elastomers do not burn easily. This means thattheir limiting oxygen index is always above 20% (a.5,a.6, a.7 and other standards related to flammability),and, burning tests, e.g., UL94 HB, are easily passed.Once a silicone burns the spread of the flame is slowand the combustion products are silica, CO, CO2 andwater, products with low toxicity.
Figure 4
Weight loss of ELASTOSIL® LR 3003/50 as a function of post curing time
Figure 5
Compression set (DIN 53517) as a function of post curing time and sample thickness forELASTOSIL® LR 3003/50
Silicone Elastomers
24
Unlike most organic elastomers, silicone will not onlyform such harmless combustion products, it will alsoproduce very little smoke and, hence, permit a gooddegree of visibility in the event of a fire.
Further, silicones are capable of forming a stable ash,which in extreme cases will turn into very hardceramic, as discussed under safety cable materials(Section 3.3).
The advantage of such an ash forming behaviour duringburning is also very useful in the case of door seals, orany kind of gasket that needs to have sealing propertiesat least against the spread of flames or smoke, as in thecase of two sections of a building, for instance.
Many of the recent and past accidents in buildings,aeroplanes, ships, etc., could have resulted in asignificantly lower number of victims if siliconeprofiles or cables had been used correctly.
3.9.2 Aerospace
Because of their resistance and relatively smallvariation of properties across a vast temperature range,silicone elastomers have occupied a substantial part ofthe market for aeronautic applications for rubberymaterials.
Phenyl methyl silicone elastomers retain lowtemperature flexibility in extreme conditions evendown to –110 °C.
The applications of silicone elastomers range fromadhesives in satellites and aeroplanes to componentsof wings, landing flaps, window gaskets, floorcomponents and many more parts.
It goes without saying that the other properties ofsilicone elastomers and rubbers such as heat and UVresistance, and the hydrophobic behaviour, contributeto their wide usage across these industries.
3.9.3 Building
New technologies for modern buildings have evolvedover the last 3 decades in the form of structural glazing.This building concept involves covering the fronts ofbuildings with glass panels.
The glass is held in place by applying adhesives,elastomeric profiles and rigid structural elements.
Over the past 5 years the building industry has alsoput i ts focus on design aspects. Functionalelastomeric profiles are no longer invisible.Moreover, they have become part of the designconcept of the buildings.
With such design requirements and the conditionsthat are imposed on large buildings, silicone hasbecome a good option for elastomeric profiles andsilicone adhesives are well established. This ismainly due to cold flexibility, almost indefinite UVstability and relatively low compression set.Needless to say, silicone rubber profiles are availablein any colour whereas all organic rubbers havecertain restrictions.
3.9.4 Pharmaceutical
Many pharmaceutical tubings, fittings, gaskets andthe like contain silicone rubber, because of its ‘inert’behaviour towards certain media and itsresterilisability.
3.9.5 Spin Casting
Silicone elastomers provide an economically idealsolution, for shaping metals with relatively lowmelting temperatures.
These alloys are cast into a rotating silicone disccontaining a certain number of cavities. Because ofthe heat stability of the silicone rubber the number ofcasting cycles is approximately 100-500 dependingon the metal and the size of the parts.
Silicone rubber has to exhibit an utmost degree ofheat and reversion stability. A specially designedsolid silicone rubber with a hardness of around 40Shore A is used as a raw material; it is mixed withground quartz in order to obtain the requiredhardness, catalysed with dicumyl peroxide. The mixis cut into discs, into which one imprints thenegative halves of the originals and the runnersystem. The discs are cured at >160 °C and are thenready for use.
This technology is related to mould making as onemakes multiple copies out of an original.
Silicone Elastomers
25
4 Composition and Function ofSilicone Elastomers
4.1 Introduction and Classifications
All silicone elastomers consist of crosslinkedpolydimethyl siloxane (PDMS) molecules, fillers andadditives.
Tentatively, apart from the curing temperature, thedifferences between RTV, HTV and LR are themolecular mass of the raw materials, as indicated inTable 18.
Similar amounts of fillers are used in general. Allsilicone elastomers typically contain between 0% and40% fillers. The bulk of this is fumed silica with surfaceareas between 150 and 300 m2/g. Fillers are responsiblefor the mechanical and flow properties.
So-called inactive fillers do not reinforce the elasticsilicone network. They are widely used in order to improvecertain chemical or thermal properties. Examples of suchfillers are ground quartz, diatomaceous earth and chalk.Too high levels of such inactive fillers result in loss of theexcellent mechanical properties of most siliconeelastomers. However, loads of up to 100 parts per 100parts rubber are occasionally used in order to make thesilicone compound cheaper. This latter degree of fillingis not advisable, as the resulting compounds behave morelike elastic rocks than elastomers.
It goes without saying that a high degree of filling resultsin very high densities and thus a high weight per part.
4.2 Properties of Silicone Elastomers
The generally advantageous properties of siliconeelastomers are as follows:
• flexible in the cold down to –40 °C, in special,extreme cases –55 °C
• heat stable almost indefinitely up to 180 °C in hotair, with special additives up to 250 °C and for ashort term even to 350 °C!
• transparent: also addition curing grades withoutyellowing
• compliant with food regulations such as BgVV,FDA, etc.
• sterilisable by gamma irradiation, steam andethylene oxide
• very low compression set at elevated temperatures
• low flammability, non toxic combustion products
• unique electrical insulating properties, highdielectric strength >20 kV/mm (1 mm test slab),high volume resistivity of approximately 1015 Ωcm
• high durability
• good mechanical properties
• unlimited pigmentability, etc.
Most silicone elastomers possess these generalproperties. Their most unique property, however, is thecomparatively constant elastic properties between-40 °C and +180 °C. No other organic or inorganicelastomer is capable of maintaining its properties oversuch a wide temperature range, except forfluoroelastomers, which seem to have comparablestability in terms of working temperature.
Table 19 shows some of the mechanical properties ofa typical HTV elastomer for various temperatures.
Table 20 gives a rough comparison between theperformance of silicone elastomers and some otherrubbers. Table 21 gives a comparison of the propertiesat different temperatures of EPDM, a silicone elastomerand a natural rubber (NR).
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4.3 Chemistry and Curing Mechanisms ofSilicone Elastomers
Silicones and silicone elastomers originate from 'sand'.Even though this is not as simple as it sounds, thecomplex chemistry and versatile properties of siliconesare ‘built on sand’, as shown in Figure 6.
Figure 7 shows a schematic overview of the processingand product groups for silicone elastomers.
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27
5 Room Temperature VulcanisingSilicone Elastomers
5.1 General
Many RTV systems are widely used as siliconesealants or adhesives. However, their individualfunction is not typical of the application of siliconeelastomers. It is more related to sealants used instructural glazing and in the building industry. Insilicone elastomer technology these systems are used
for joining silicone profiles and moulded parts. Theapplications of such adhesives range from buildingto healthcare and from automotive to aerospace.However, these materials are excluded fromdiscussion in this review as this would be beyond itsintended scope.
RTVs with clear elastomeric functions are materialsthat act as static or dynamic parts, e.g., gaskets,prototypes and mould making aids. RTVs are also usedto produce moulded parts, e.g., electrical insulators formedium and high voltage.
Figure 6
Schematic of the production of silicone elastomers
Figure 7
Products and processing technology for silicone elastomers
Silicone Elastomers
28
5.2 Condensation Curing RTVs
In most cases RTV systems are condensation curing.The curable composition is formed by mixing twocomponents, or in the case of one component systems(RTV-1) it is ready to use and it will cure after itsapplication out of the packaging. The major part of thecuring system is a PDMS (polydimethyl siloxane)polymer with terminal hydroxyl groups and areinforcing filler. As additives it contains a crosslinker,usually a functional silane, and a catalyst, in many casesa tin complex.
The curing systems are classified by the chemicalnature of the split products formed during thecondensation process, when the functional silane isincorporated into the polymer network splitting off thecondensation products.
Table 22 shows examples of the current mostfrequently used curing systems, classified accordingto their acidity – acidic, neutral or basic.
Such systems cure in the presence of air moisture. Asthey form split products during their cure, such materialsexhibit shrinkage with increasing degree of curing.
The characteristics of a condensation curing system are:
• The reaction is isothermal.
• The volatile alcohol, oxime, amine, etc., is formedas a condensation product.
• A mass loss occurs due to the volatilisation of thesplit product, e.g. alcohol, which results in a‘chemical’ shrinkage of the cured rubber in therange of 0.2-2 % (linear), depending on theconcentration of reactive groups.
• In most systems the curing reaction reverts attemperatures exceeding 90 °C if the reaction isincomplete.
• Retardation of cure occurs if there is a lack ofmoisture in the rubber or the ambient atmosphere.
The mechanism of condensation curing is illustratedin Figure 8. In this curing process a silicone polymerwith terminal hydroxyl groups reacts with a crosslinkerwith at least 3 alkoxy, carboxyl, amino or oxime groupsin the presence of moisture. Organotin complexes actas catalysts.
5.3 RTV-1 for CIPG and FIPG
RTV-1 systems often find applications as gaskets. Thegasket technology is termed Formed-In-Place-Gasket(FIPG) and Cured-In-Place-Gasket (CIPG). Mosttypically RTV-1 systems are used as FIPG materials.They are used in automotive applications in order toseal engine segments such as the lubricating andcooling regions of the engine.
The rheology of these RTV-1 sealants allows for fullyautomatic application with a low degree of waste,simple substrate treatment and design.
Once cured, the CIPG gaskets stick to the substratesand allow for good protection against loss.
In FIPG technology the gasket cures after joining thetwo parts (e.g., flanges) that are to be sealed off. Thisallows for quite low requirements in respect ofdimensions as the sealant adapts itself to the spacebetween the two parts. No special surface treatment ofthe flanges is required.
The use of material is economic. Correctly appliedFIPGs help to avoid leakages which could result frominserted gaskets or CIPGs.
Table 23 shows the properties achievable with RTV-1CIPG materials, which are commonly used inautomotive and other high performance applications.This serves as an example of media and heat resistance.
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Silicone Elastomers
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CIPG and FIPG techniques are also used across otherareas, for example in steam iron gaskets. Therequirements are similar to those of the automotive areas.
5.4 RTV-1 for Baking Tray Coatings
These RTV-1 systems are applied by spraying, theirrheology is adjusted to give a low viscosity. Typically,one would use acetoxy systems, such as the exampledescribed in Table 24. Baking trays are used at elevatedtemperatures. The RTV coating acts as a heat stablerelease agent. (Silicone oils and emulsions are also usedas release agents in the tyre industry.)
5.5 Adhesive RTV-1 Materials
This area is somewhat related to FIPG/CIPG. FIPGsealing techniques can also be used as adhesivetechnology in various application areas.
Acetoxy systems are widely used as so-calledgeneral purpose adhesives. Table 25 provides arough overview of RTV-1 adhesive or coatingsystems to illustrate the variety of properties andproducts.
As indicated in this table viscosities range from 500mPas up to several 100,000 mPas, the latter in thecase of non sag materials.
Non sag materials are required in order to fill widergaps or to allow for the application of a cord orprofile shape onto a substrate, the shape of which isstable before and during the cure.
Low viscosity adhesives are desired if the processorneeds an easily spreading or a sprayable material.
Figure 8
Reaction mechanism of the condensation curing process of RTV-1 or RTV-2 systems
Silicone Elastomers
30
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5.6 Condensation Curing RTV-2 Systems
To obtain stable systems, it is imperative to split up therubber constituents into two components in such a waythat unwanted reactions will not occur during their storage.
Condensation-curing rubbers consist of a rubber baseand a curing agent (hardener, catalyst).
Polymers, fillers, softeners and some additives arenormally contained in the rubber base, whilstcrosslinkers and tin catalysts, as well as extenders anddyes or pigments (if added for visual mixing control),are comprised in the curing agent.
Even though condensation curing systems seem to beoutdated they are still a widely considered option. Forexample, the curing reaction is hardly inhibited by
pollutants from the environment, as would be the casewith addition curing materials.
5.7 Mould Making Condensation CuringRTV-2 Materials
One of the main applications of 2-component RTVsystems is mould making. The curing agent is a liquid orpaste which is incorporated into the mould making base.Once mixed the system will cure, if enough moisture ispresent in the ambient air or the mix itself. The preferredcuring system is alkoxy based, i.e., the split product is analcohol.
Table 26 provides us with an overview on commonlyused mould making RTV materials and their properties.It can be quite difficult to pick the right material for a
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1742M elbadaerpS 000,052 55 5.4 071 7> 4.0
0044M elbaruoP tfos, 000,52 32 5.2 052 3> 7.0
0444M elbaruoP drah, 000,52 73 0.2 002 3> 4.0
3054M elbaruoP tfos, 000,04 52 0.5 053 02> 5.0
4154M elbaruoP tfos, 000,52 52 5.4 054 52> 4.0<
noitiddAB/A0064M elbaruoP tfos, 000,51 02 0.7 008 02> 1.0<
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noitiddAB/A2464M elbaruoP drah, 000,51 73 0.7 055 03> 1.0<
Silicone Elastomers
32
given application. This is why mould makers rely onselection guides and technical service as provided byraw material suppliers.
5.7.1 Speciality Mould Making RTV-2 Materials
Material selection essentially depends on the mouldingtechnique, the geometry to be duplicated (undercuts,etc.), the required chemical resistance and mechanicalproperties of the silicone material.
Table 27 provides an overview of speciality materialsand their properties. In most cases copies are beingmade of other pourable systems, which are eitherchemically aggressive or hot, etc.
The heat stabilised materials of Table 27 are also heatconductive, which allows the replica to cool off morequickly.
5.8 Condensation Curing RTV-2 Compoundsfor Encapsulation
These materials are used for encapsulation ofelectric or electronic components. They have lowviscosities (900-10,000 mPas) with good dielectric,i.e., insulating properties, as summarised in Table28. They require between 2% and 10% catalyst/hardener.
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Silicone Elastomers
33
5.9 Adhesives and Sealants Based onCondensation Curing RTV-2 Compounds
Condensation curing RTV-2 adhesives are less commonthan addition cured adhesives. This has to do with thefact that there are numerous RTV-1 systems with a goodprocessing time.
They are used in FIPG technology, in particular whereinhibition (e.g., by amines, sulfides or organic acids)limits the use of Pt-curing technology (Table 29).
5.10 Addition Curing RTV-2 Systems
Such systems are mainly two component materials,because the reactive constituents, which allow curingat room temperature with no split products and noexternal reactant (such as air moisture as mentioned incondensation curing) need to be kept separate.
Most common addition curing RTV systems areavailable in mixing ratios of 1:1, 9:1 or 100:1. Variablemixing ratios are possible.
Usually the reaction is very fast, once the twocomponents are mixed. The processor has to use themixture within a certain time period. This time is calledpot life. Once pot life has expired it is no longer possibleto process these materials correctly.
As the curing reaction is not accompanied by theformation of any split products addition curedelastomers do not exhibit shrinkage upon curing, whichleads to easy control of shapes and dimensions.Furthermore such systems are practically odourless.The principle of the addition reaction is shown inFigure 9. The same mechanism is typical for additioncured LR and HTV compounds.
The curable composition contains polydimethylsiloxane polymers with terminal and/or non terminalvinyl groups. As a crosslinker a polydimethylsiloxane polymer with Si-H groups is added. Thesystem starts to cure, once a platinum compound isadded as a catalyst. An inhibitor regulates the rateof the curing reaction.
Such compositions often contain a reinforcing filler,e.g., fumed silica with surface areas of 100 to400 m2/g, allowing for good mechanical propertiesof the cured mixture.
As indicated in Tables 26 and 27 addition curedsystems exhibit a number of advantages in mouldmaking. One would expect that these advantages arealso present in the case of encapsulating, potting oradhesive RTV-2 systems.
This is the case because such materials are widelyused in industrial mass production, where cycle times(i.e., times to produce one unit) and precisedimensions are a must. The latter is better met withaddition curing materials as they do not shrink uponcure, whereas substantial shrinkage is found usingcondensation curing materials. A clear plus is theabsence of split products as formed in the curingprocess of condensation cured materials (andperoxide cured HTV, as described later).
A disadvantage is the possibility of cure inhibition,if amines, sulfurous or other catalyst poisonsdeactivate the Pt catalyst.
Viscosity values range from well below 10 Pas to50 Pas and above. Above 10 Pas the mechanicalproperties such as tear resistance, tensile strengthand elongation at break are quite good, whereas thesevalues are less at very low viscosities.
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Silicone Elastomers
34
RTV-2 systems with high viscosity (50 Pas) can bedesigned as sponge formulations with moderatemechanical properties.
5.11 Silicone Gels
Silicone gels are addition curing RTV-2 systems, uponcuring they form an elastomeric network with a gel-like consistency. By varying the mixing ratio it ispossible to adjust the consistency of the gel from nearlyliquid to hard.
As these gels tend to be very soft, their hardness is notmeasured in Shore A units but using the penetration
method. This hardness measurement involves a conewhich is immersed into the gel. The depth of thispenetration is recorded, and it provides the value forthe hardness of the gel.
Silicone gels are widely used in healthcare, electronicsand automotive areas. Applications range fromdamping gels in sporting goods, operation pads andencapsulated electronic components such as integratedcircuits to rain sensors, etc.
While allowing for a wide range of hardness, themechanical strength of the gels is very poor. Theirtransparency, however, is excellent because of theabsence or very low content of filler(s).
O Si
CH3
CH3
CH = CH2 + H Pt catalyst
Si
CH3
CH3
CH2
Si
O
O
CH3
Crosslinker
Polymer chain end
SiH3C H + H2C = CH
O
Si
CH3
CH3
O
O CH2 Si
O
O
CH3
SiH3C CH2
O
CH2 Si
CH3
CH3
O
Rubber
Figure 9
Reaction mechanism of addition curing RTV-2 silicone rubber systems
Silicone Elastomers
35
5.12 Addition Curing Systems for Mould Making
While processing and properties are roughly the sameas with condensation curing materials, mould makingwith addition curing systems has vast advantages.Tables 26 and 27 have illustrated the characteristics ofaddition curing RTV-2 systems.
It goes without saying that these advantages ordifferences compared to condensation curing systemsare also of importance when it comes to applicationsin automotive, aerospace and household applications.Table 30 shows the fundamental differences betweenthe two curing systems.
5.13 Addition Cured RTV-2 Systems forEncapsulation
These materials range from very low viscosity withstandard silicone properties, medium hardness forgeneral purpose applications, to very high density andthus heat conductivity for special encapsulationprojects. Most of these materials are mixed in the ratio9:1, where the small component has a much lowerviscosity than the large one.
Table 31 shows examples of a number of widely usedRTV-2 encapsulating materials.
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Silicone Elastomers
36
5.14 Addition Cured RTV-2 Adhesives andSealants
Low viscosity is no longer desirable in the case ofadhesives. They should exhibit a certain rheologicalbehaviour allowing for their proper application onto thesubstrate(s) that have to be glued together. Theseadhesives are called RTV-2 systems for historic reasons,as they are actually high temperature curing.Characteristic curing times range from 5 minutes at 150°C to 1 minute at 200 °C, the latter also allowing for asubstantial pot life at room temperature. Table 32 showssome properties of silicone adhesives. One componentmaterials are marked 1K. Non sag adhesives are alsosuitable for FIPG and CIPG technology.
5.15 Addition Cured RTV-2 Foam forCompressible Gaskets
The latest generation in gasket materials are silicone foamswhich were derived from RTV technology. The processorsaim for silicone properties and, at the same time, for weightreduction and/or for low heat conductivity.
These foams can be used in multi-purposeapplications, and, they can be applied in sheets, stripsor cords, all of which are fairly easy to produce,allowing for a very uniform and closed cell structure.
These foam compositions allow the production ofsoft gaskets which are compressible. In siliconeelastomer gasket technology this is a breakthroughas even the softest sil icone gel is nearlyincompressible.
Addition cured silicone foams have to develop a gasas they start to cure. This is usually hydrogen,developing from a second reaction of the silicon-hydrogen groups which take part in thehydrosilylation crosslinking process. This reactiontakes place in the presence of hydroxyl groups whichare present in the formulation.
As in other RTV-2 systems the foams are designedto be self levelling or non sag, the latter allowingfor use in Formed-In-Place-Foamed-Gasket (FIPFG)technology.
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Silicone Elastomers
37
The applications are in all areas such as automotive,aerospace (seat components), building industry (flameretardant cable bushings) and mouldings, using selflevelling foams that are poured into moulds of therequired shape.
The mixing ratios are 1:1 and variable in many cases.The foam densities are as low as 300 kg/m3, or lowerin special cases as shown in Table 33.
As these materials develop some amounts of hydrogenduring the processing, sufficient ventilation must besupplied for safety reasons.
In order to apply foams such that they stick to surfaces,one has to use silicone primers in the same way as withconventional techniques for silicone rubber bonding.
6 Liquid Silicone Rubber
6.1 General
All liquid silicone rubbers are addition curing. Theycure at elevated temperatures and their main use is insilicone mouldings produced by injection moulding,and textile coatings.
The scope for application of liquid silicone rubbers ishuge (a.8) (49). In injection moulding they are used
where large series need to be produced and the costper piece is a big issue.
To a certain extent their use is highly competitiveagainst RTV and HTV solid silicone rubber, even incase of applications in the transmission anddistribution industry, such as medium and high voltagecable accessories and smaller insulators. This is dueto the short curing time and available processingtechnology, allowing for an utmost degree ofautomation and almost waste free production.
6.2 Curing Mechanism of Liquid SiliconeRubbers
The curing mechanism is the same as for the additionRTV-2 systems (see Figure 9). The mixing ratios ofthe single components vary from 1:1 to 100:1 in thecase of RTV-2, whereas liquid rubbers are mosttypically 1:1 systems. The difference in thecompositions is such that the catalyst (A component;Pt-complex) and inhibitor levels (A and B components;alkyne alcohol) are set in order to provide virtually nocuring at room temperature, and high speed of curingat elevated temperatures (for example, when the coldmaterial hits the hot walls of the mould during theinjection moulding process).
Figures 10, 11 and 12 demonstrate the curingcharacteristics for liquid silicone rubber.
Figure 10
Non isothermal curing characteristics of an addition-cured LR and a peroxide-cured HTV silicone(linear scan at 10 °C/min)
Silicone Elastomers
38
Please note that a noticeable degree of curing onlyoccurs after 70-100 hours from mixing A and B at roomtemperature. This time changes to ‘indefinitely’ at–20 °C and ‘seconds’ at 180 °C, respectively.
6.3 Standard Liquid Silicone Rubbers
Standard liquid silicone rubbers originate from generalrequirements that have evolved from the markets forsilicone elastomers over the past 25-30 years. Theseproducts are also known as general purpose LR.
Liquid silicone rubbers have been on the market for30 years with annual growth rates of +10% and higher.Such materials have undergone several innovativechanges, especially over the past 10 years. Thesechanges relate to specifications and curing speeds, etc.
The purpose of new fast curing materials compared tostandard grades is to reduce the cost per piece, whichresults from shorter cycle times during processing.These liquid rubbers not only have the samespecification but also they are chemically identical totheir older predecessors after post cure. Table 34 shows
Figure 11
Isothermal curing characteristics of a LR. Curing times of ELASTOSIL® LR 3003/50 at different temperatures.
Figure 12
Pot life of a LR as a function of temperature. Viscosity of the AB mixture of ELASTOSIL® LR 3003/50 as afunction of time and temperature (Brookfield viscometer)
Silicone Elastomers
39
examples of the materials available comparing fast cureand standard grades of LR. Fast curing technologyallows the processor to choose a lower mouldingtemperature to achieve the same or still shorter cyclesas with a standard material. This is emphasised by thebold letters in the table. Fast curing LR compositionsalso provide a new and very interesting possibility,comoulding with thermoplastics.
Standard LRs are specified by original equipmentmanufacturers in automotive, healthcare and domesticappliances.
The typical hardness range for standard liquid siliconerubbers is between 10 and 80 Shore A.
6.4 Speciality LRs
6.4.1 High Tear LR
High tear resistant LRs were initially developed in orderto provide maximal mechanical strength to baby soothersand baby bottle nipples. Today’s global market for suchapplications is easily beyond 1,000 tonnes per year, andit is characterised by significant growth as a replacement
for latex products, which possibly still account for morethan 60% of elastomeric baby feeding applications.
High tear LR is continuously being used to substitutesolid silicone offsets and also organic rubbers. Most ofthese substitutable materials have quite highmechanical strength which is of importance either inthe application, for material approval by originalequipment manufacturers (OEMs), and/or duringprocessing such as demoulding or assembly, etc.
Table 35 shows a comparison between the tearresistance of high tear LR and HTV (a general purposeHTV would be similar to standard LR) (a.9).
6.4.2 No Post Cure LR
Standard liquid rubbers allow for a relatively lowcompression set. This is achievable only after post cure.Compression sets as low as 10% or even lower arepossible. Without post curing such materials will havea compression set of 70%.
As the process of post curing is energy intensive andsubstantial lowering of the compression set is usuallyachieved after 6 hours at 200 °C consuming up to 125
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Silicone Elastomers
40
l/kg silicone/min of fresh air, many new liquid rubbersare being formulated to allow for a low compressionset even without post cure. These are denoted as NPC.The test method is DIN 53517, 22 h at 175 °C. Table36 gives a comparison between various grades and theirpost cured (PC) and no post cure (NPC) compressionset (CS). The most common values are shown as arange. See also Figure 5 on compression set.
The table is complemented by values for HTV rubbers.
Typically, post curing must be applied in all medicaland food contact applications.
NPC materials are thus limited to technicalapplications. Most technical liquid rubbers includeNPC technology as part of their formulation.
6.4.3 Heat Stabilised LR
In many automotive applications it is necessary to useLRs which are heat stabilised. Often, this can beachieved by colouring the rubber with a metal oxidecontaining pigment paste.
As per requirements from suppliers of ignition systems,new grades of LR were developed which are readilystabilised, black and do not require post cure (NPC).They are commonly used in spark plug boots.
Table 37 provides a rough comparison between an 80Shore A hard LR, both stabilised and without additives.A carbon black pigment paste has been used as astabiliser. Changing to lower hardness, heat stability getsbetter, the optimum being between 50 and 60 Shore A.
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Silicone Elastomers
41
6.4.4 Coolant Resistant LR (NPC)
Gaskets for radiators in automobiles are a developingapplication for LRs.
The requirement is to have a gasket of rubber with aslittle change in properties over time as possible. Therubber gasket has to withstand coolants, usuallymonoethylene glycol (MEG) in water, at temperaturesof above 100 °C and a hot air environment at the outerside of the radiator. Further, the gasket must notembrittle at low temperatures.
Traditionally such gaskets have been made of EPDMrubbers. EPDM has better mechanical properties andcoolant resistance than silicone elastomers. However,coolant resistant silicone rubbers show the lowestrelative change in compression set in hot air and muchsmaller relative change in other parameters as shownin Table 38.
Such coolant resistant LRs can be used in a number ofdifferent, non automotive applications, because theyhave an increased chemical resistance in general.
6.4.5 Self Lubricating LR (NPC)
Such rubbers are also called oil bleeding or oil exudingmaterials. They are similar in appearance to standardsilicones once moulded. After some time they start toform an oily film on the surface of the parts.
They are most commonly used in the manufacture ofgaskets for electric connectors. The oil film serves asan aid during assembly, and, it improves thehydrophobic behaviour of the seal (this is why the namefor the assembled connectors is ‘weather pack’).
Typically the oil content ranges between 2% and 7%and the speed and amount of oil bleeding correspondsto these contents.
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Silicone Elastomers
42
The oil (also known as bleed fluid, etc.) is a phenylpolydimethyl siloxane. Because of the content ofphenyl groups this oil is not compatible with thematrix of the silicone rubber. As a consequence itmigrates freely through the elastomeric networkresulting in the formation of an oil film on the surfaceof the parts (15).
6.4.6 Oil Resistant LR (NPC)
Silicone elastomers and in particular siliconerubbers, both solid and liquid have relatively poorresistance when in contact with apolar media suchas engine oils and the like.
However, it has been possible to formulate liquidsilicone rubbers with increased oil resistance.
Oil resistance typically is measured at 150 °C for72 hours. The changes in hardness and mechanicalproperties again should be as small as possible overtime. In addition, because of the apolar character ofthe silicone network and the apolar composition ofengine oils the rubber absorbs part of the oil whichcauses it to swell. The increase in volume should beas small as possible.
The older formulations for oil resistant liquid rubberscontain a passive filler and certain additives. Thefiller, however, eventually causes problems in mouldtechnology and machinery as it is strongly abrasive.
The latest technology allows for non abrasive liquidsilicone rubbers with the same oil resistance. Table39 shows a comparison between standard liquidrubbers and oil resistant LR, both abrasive and nonabrasive.
6.4.7 Self Adhesive LR
6.4.7.1 Self Adhesive LR for Technical Applications
Self adhesive LRs have been known in the marketfor some years. However, the name self adhesiveindicates that it could be tough to make it stick wheredesired and yet easy to demould at the same time.Processors helped themselves by teflonising mouldsurfaces when processing self adhesive liquidrubbers.
The advantage for the processor of self adhesivetechnology clearly is the simplicity of combining plasticwith silicone elastomers without using a primer.
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Silicone Elastomers
43
The latest, very exciting developments allow thesilicone rubber processors to injection mould selfadhesive LRs onto substrates with good adhesion.At the same time these materials are easy to demouldwithout the need of release coatings such as teflon(the latter has to be renewed from time to timeresulting in undesirable shut downs; also teflonimpairs the heat transfer). Adhesion builds up on atime scale which is usually much longer than themoulding cycle alone, as shown in Figure 13. Thisfigure also provides an explanation as to why thisnew self adhesive material would not adhere to themould surface.
Table 40 shows a compilation of substrates to whichadhesion is possible. With great pleasure the author wouldalso like to point out that it is possible to achieve adhesionon steel inserts without causing problems in demoulding.
The only restriction about self adhesive technology isthe fact that it is only suitable for technical applications.This has to do with non compliance with the BgVVand FDA (regulations for food contact and medicalmaterials), both of which require post cure in order toreach the prescribed volatile and extractable levels. Apost cure at 200 °C over several hours will destroy orat least seriously affect the plastic substrate.
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Development of adhesive force over time
Silicone Elastomers
44
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…deunitnoc
Silicone Elastomers
45
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Silicone Elastomers
46
6.4.7.2 Self Adhesive LR in Food and RelatedApplications
The latter facts led to the development of a self adhesiveLR which is suitable for contact with food after postcure. However, this would still harm the plasticsubstrate, although some plastics withstand a post cureat 200 °C, such as PBT.
This recently developed LR adheres well to some PBTgrades (e.g., PBT Pocan B 3235 of Bayer, PBT UltradurB4300G6 of BASF).
Further, it shows a stronger adhesion to other substratesthan with standard silicones.
It would go beyond the scope of this article to go intofurther detail on self adhesive liquid rubbers. For furtherinformation refer to Rapra’s Handbook of RubberBonding containing an interesting review on thebonding of silicone rubber, or contact the raw materialsupplier (a.11).
6.4.8 Electrically Conductive (AntistaticSilicone!) LR
It is quite remarkable that it is also possible to formulatean electrically conductive LR out of one of the bestelastomeric insulators.
If a liquid rubber is filled with substantial amounts ofcarbon black its volume resistivity drops from 1015 Ωcmdown to below 12 Ωcm. This is accompanied by a strongincrease in viscosity, which rises from approximately1,000 Pas to 8,000 Pas at a shear rate of 1 s-1 (cone plateviscometer).
By varying the amount of carbon black, the siliconesupplier is able to provide electrically conductiverubbers in a range of conductivities, as shown inTable 41. Note that the viscosity increases with higher
conductivities. This has to do with the load of carbonblack, which is used to make the silicone rubberconductive. The same conductivities can be realisedwith HTV rubbers.
The use is various, it ranges from conductive pills inelectronic keypads (standard silicone keypad withconductive pills stuck onto it) to so-called stress conesor deflectors in transmission and distribution (T&D)industries. The latter being an application for mediumvolume resistivities.
Unfortunately, because of the nature of carbon black,it is not possible to achieve resistivities which wouldjust provide antistatic behaviour without making thesilicone a good conductor, viz. applying it in volumeresistivities of approximately 1,000 to 5,000 Ωcm. Thisrange is not achievable on a basis which is accurateenough to make antistatic parts, this is due to the factthat resistivity rapidly increases by approximately 5 to8 decades in a narrow range of concentrations (similarto a step function).
6.4.9 Flame Retardant LR
Many consumer electronics contain silicone rubber. Inmost cases standard silicone rubbers are satisfactorywith respect to their flammability.
However, if it comes to high voltage areas such as TVtubes and the like, the requirements for flameretardancy are raised. This means that the materialsmust have a limiting oxygen index of at least 27% anda UL94 rating of V0.
Table 42 shows the differences between standard LRand flame retardant LR.
As mentioned in the applications sections, such rubbersfind their applications in anode caps.
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Silicone Elastomers
47
6.4.10 Extra Liquid Rubber (XLR®)
In some applications such as in transmission anddistribution or for the manufacture of parts with shotweights of several kilograms, it would be necessaryto use injection moulding machines with extremelyhigh clamping force.
Parts of this size not only exhibit very long fillingtime during injection but also high internal pressureduring the cure (the pressure is a consequence of thethermal expansion of the liquid rubber). Further, thecuring times are very long and can easily reach 30minutes to hours.
These difficulties led to the development of extraliquid rubber (XLR®). This material has an extremelylow viscosity allowing for a quicker filling step. Alsothis viscosity allows it to be used in a simple mouldwhich does not require an injection mouldingmachine. The typical mould temperature generally liesbetween 100 °C and 130 °C in this latter case.
The viscosity is down to 100 Pas compared to 500 Pasin the case of a standard LR.
6.4.11 Other Types of LR
It goes without saying, that, at least in theory, onecould combine the LR technologies in order toformulate new compositions. This is possible, e.g.,in the case of self adhesive silicone rubbers. Examplesare: self adhesive, oil resistant LR; and self adhesive,oil bleeding LR.
6.5 Pigment Pastes
Another advantage of silicone elastomers is theirpigmentability. Suppliers have a range of pigmentpastes permitting almost any colour. The user has tomix these pastes in certain ratios in order to obtainthe desired colour. This mix is then added to thesilicone rubber via the colour line of the injectionmoulding machine.
The pastes deep black, ivory and red iron oxide alsoact as heat stabilisers.
Such pastes essentially contain a vinyl siliconepolymer and the pigment. We have already shown thestabilising effect of pigment pastes.
It is highly advisable to the processor to use LR andpigment paste from the same supplier where possible.Then the system is stable, whereas in the opposite casethe pigment paste could affect the performance of the LR.
7 Solid Silicone Rubber
7.1 General
The consistency of solid silicone rubber is reminiscentof plastilline. Hence, its viscosity is lower than that oforganic rubbers. This consistency is such that it ispossible to supply solid silicone in almost any shape.
The available geometries range from simple strips (asthey come off the two roll mill), cords, coils, blocksand profiles to pellets.
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Silicone Elastomers
48
In terms of chemistry there is a major difference betweenRTV and LR. In the first place there is the much higherviscosity. Consequently the molar mass of the polymerswhich form the elastic network is much higher.
Because of this high molar mass, cured HTV usuallyhas a lower crosslink density or at least a differentnetwork structure than RTV or LR and thus much bettermechanical properties.
This mainly holds for peroxide cured HTV rather thanfor addition cured HTV, the latter exhibiting very highmechanical strength but relatively poor recoveryproperties (which can often prove to be advantageous).
Curing mechanisms are restricted to peroxide (Section7.2.2) and addition cure.
No condensation cure is known for HTV silicone rubber.
7.2 Curing Mechanisms of Solid SiliconeRubbers
7.2.1 Addition Cure
Please refer to Figure 9 in Section 5.10. What is verymuch different with addition curing HTV is the factthat it is available both as a one component system,yet exhibiting a considerable life time, and a twocomponent system.
The one component system represents the mostspectacular recent development available on thesilicone market.
Unlike LR, these systems are stable between 2 monthsand even up to 12 months, both at room temperature.
The 2 month system is used for extrusion, the 12 monthsystem is used for moulding.
Because of some uncertainties during transportationof such uncured rubbers to the processors, the providerwill not guarantee any longer than 2 or 3 months aftershipment.
In the second case, the two component system, theprocessor will get two separate components which havea considerably longer shelf life. The mixing ratios rangebetween 1:1 and 100:1.5. For the first mixing ratio,component A again contains the Pt catalyst and B thecrosslinker and inhibitor(s), the latter being the sameas used in LR.
In case of the 100:1.5 system the components are abase and the catalyst. The small component containsPt whereas the large one consists of HTV rubber base,crosslinker and inhibitors.
The life time of the two components as mixed rangesbetween 6 hours (for 1:1 extrusion), over 24-48 hours(for 100:1.5 for extrusion), to more than 1 week (for1:1 moulding).
To date processors seem to prefer 1:1 systems.However, in order to become competitive, such systemswill in future be substituted for 100:1.5 or onecomponent systems because of economic advantagesand increased flexibility.
Currently the preferred curing system is peroxidecuring HTV, which is described below. To dateprocessors seem to prefer such systems for variousreasons including price. The disadvantages of peroxidecured HTVs are:
- Yellowing after post cure,
- Smell in production,
- Peroxide residues in the rubber,
- Regulatory issues (in case of extrudable HTV),
- Surface with very high friction coefficient (so-called surface stickiness),
- Smell and taste issues, and
- Peroxide split products in the atmosphere.
Therefore the future of solid silicone rubber is inaddition curing technology. Its advantages arenumerous and compelling. Today most pharmaceuticalapplications have switched to the use of addition curetechnology, with the following benefits:
- No yellowing, even after post cure,
- Smell free, cleaner production,
- Very dry surface,
- Easy to demould, no air inhibition,
- High transparency,
- High tear and tensile strength,
- No post cure necessary, and
- No peroxide split products or remainders in the rubber.
Silicone Elastomers
49
The fact that it is possible to pelletise solid siliconerubber opens up a very wide spectrum of possibilitiesfor automation (which also holds for peroxide curedsystems).
Another beauty of addition cured technology is theabsence of peroxide split products. Hence, a post cureis not necessary for many applications. However, thelatter is obligatory if one wants to reach compliancewith FDA, BgVV, or to produce cured goods to go intomedical devices.
7.2.2 Peroxide Cure
The most commonly used peroxides are shown, byapplication, in Table 43.
The function of the peroxides is the same. Theseperoxides are chemically stable at room temperature.At elevated temperatures their molecules split andprovide radicals which cure the silicone rubber.
The different chemical structures of the three peroxidesdetermine their use. C1 and C6 split at relatively high
temperatures (C1 at 155 °C and C6 at 160 °C).Therefore they allow the filling of the mould beforecuring. They are not suitable for extrusion because theyreact with ambient air at elevated temperature ratherthan with the vinyl groups of the silicone rubber. Thisbehaviour is also called air inhibition.
Crosslinker E is suitable for extrusion. It splits at>90 °C, and it has a very minute tendency to airinhibition. It is less vinyl specific than C1 or C6.Therefore it is possible to cure a HTV rubber, thepolymer of which is pure polydimethyl siloxane.
A post cure is needed after the initial cure duringextrusion or moulding, if one wants to reachcompliance with FDA, BgVV, or to meet medicaldevice specifications, or obtain smell free products witha low content of volatiles.
7.3 Standard Solid Silicone Rubbers
Standard HTVs are peroxide curing general purposegrades. They originate from the very first HTV gradesthat were provided to the silicone elastomer markets.
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Silicone Elastomers
50
However, their spectrum of properties and productionroutes have been modernised gradually over the past30 years. Also, the number of available products hasincreased to a much wider range of hardness.
General purpose rubbers usually are essentially suitablefor moulding and extrusion.
All general purpose materials are transparent. Manyof them are suitable for applications across all industriesincluding healthcare.
Table 44 shows a rough summary of standard solidsilicone rubbers (HTV) and their features.
The typical tolerance from lot to lot for the hardness ofHTV silicone rubbers is +/- 5 points Shore A.
There are other novelty or speciality HTV productgrades. It is difficult to describe the scope of theserubbers to the full. One section here is also dedicatedexclusively to addition curing HTV.
7.4 Speciality HTV (all peroxide)
7.4.1 High Tear HTV
High tear solid silicone rubbers HTV have a hardnessrange of 30-70 Shore A. Their tear strength is muchhigher than that of standard grades with a range ofvalues of 40-50 N/mm (ASTM 624 B).
These products exhibit slightly lower heat resistancethan general purpose rubbers. Also, their use is inmoulding, preferably.
It should be noted that it is virtually impossible to havehigh tear strength at a hardness higher than 72 ShoreA. Above this hardness, tear strength will drop toapproximately 20-22 N/mm.
7.4.2 Economy High Tear HTV
Such grades have been developed to cope with therequirements for medium to high tear strength. Theirperformance is somewhat between standard and hightear HTV. Their main advantage is a high performancemechanical spectrum coupled with cost savings relativeto high tear strength products.
The tear resistance of such products lies typicallybetween 30 and 40 N/mm (ELASTOSIL® 411/60).
7.4.3 Extrusion HTV
Special technologies are used to provide enough greenstrength to allow for the extrusion of large siliconerubber profiles. This is specially the case in tubingwith large diameters, or building profiles. Please alsorefer to the section on calendering (8.3.6).
The main hardness ranges between 60 and 75 ShoreA. It is interesting that these products also exhibitadvanced mechanical properties in line with theexcellent extrusion properties. However, they are lesssuitable for moulding.
7.4.4 Cable HTV
This is very much related to extrudable HTV. Thetypical hardness ranges between 65 and 80 Shore A.
These grades have been designed for coextrusiononto the copper leads used in the cable industry.Their mechanical properties are such that theinsulators are removable as specified by individualcable makers.
HTV silicone rubbers are used in cables because oftheir excellent electrical properties. The latter beingdesigned into these formulations for the most part.Within the cable grades there are again generalpurpose and speciality grades, this is summarised inTable 45 and referred to in Section 3.3. Table 45lists compliance with VDE Standard, VDE0303.
7.4.5 Oil Resistant HTV (NPC)
These products are similar in their oil resistance tooil resistant liquid rubbers. Likewise they are nopost cure grades as they contain an additive thatprovides the oil resistance. Such applications, beingtechnical in most cases, they will not require a postcure. Typically the hardness ranges from 40 to 80Shore A. The technique of reaching the oilresistance is the same as in the case of the respectiveLRs: special passive fillers and additives enable thisoil resistance.
Table 46 compares the oil resistance of an oilresistant HTV and a standard HTV. A higher fillercontent and a higher crosslink density aid oilresistance.
Silicone Elastomers
51
7.4.6 Electrically Conductive HTV
These rubbers are antistatic.
For moulding it is possible to use peroxide cured conductiveHTV. Its hardness ranges from 50 to 70 Shore A.
For extrusion, generally, an addition cured conductiveHTV is used. This is because the carbon black requiredfor the conductivity will deactivate peroxides in extrusion.
Typical applications would be body electrodes, leads forignition cables, conductive pills in keypads for consumerelectronics, stress cones for transmission anddistribution, etc.
The same conductivities are achievable as with conductiveLR. Again it is impossible to reach an intermediateconductivity of 1,000-5,000 Ωcm precisely enough toprovide antistatic but also insulating properties.
7.4.7 Super Heat Stable HTV
It is very unusual to have freely pigmentable andheat stable HTV. Not in the case of the highlycrosslinked super heat stable HTV. This material isheat stable without the need for a further stabiliser.Hence, it can be used at up to 300 °C.
With such advantages we also have to accept alimited selection of Shore A hardness and the factthat there are materials with better performance inextrusion.
A standard HTV would require a very good heatstabiliser to merely reach this level of stability. Thiswould imply the disadvantage of a loss inpigmentability. The colour restrictions will be to off-white to pastel colours. Table 47 shows heat ageingresults on freely pigmentable, super heat stable HTV.This material lasts up to 7 days at 300 °C.
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Silicone Elastomers
52
7.4.8 High Green Strength/Coolant Resistant HTV
High green strength products are usually good inextrusion. Some of them also are formulated such thatthey provide good coolant resistance. Recently theseproducts have started being used for turbochargerhoses, as well as radiator hoses. They are the preferredmaterial in the manufacture of fabric reinforced hoses.Their green strength is discussed under the section oncalendering (8.3.6).
7.4.9 Steam Resistant HTV
Such compounds will withstand dry steam at moreelevated temperatures than standard silicone elastomers.
Below 130 °C the steam resistance seems to be equalamong most HTV grades. Because of the drastically
increasing aggressivity of steam above this temperaturethe life time of silicone rubbers decays steeply.
While standard HTV grades show a life time at 160 °Cof 4-5 days (embrittlement and disintegration are thesymptoms of destruction), a steam resistant materialwill last for more than 6 weeks (Table 48).
7.4.10 Heat Conductive HTV
New heat conductive grades of HTV have beendeveloped. Their use is in rollers and otherapplications requiring electrical insulation, basicproperties of silicone rubber and heat conductivity ofup to 1.2 W/mK in extreme cases.
A comparison between the conductivities of standardand heat conductive HTV grades is shown in Table 49.
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7.4.11 HTV for Transmission and Distribution(T&D) Applications
These HTV grades exhibit outstanding electricalproperties.
They contain certain anti-tracking additives, fillers(e.g., aluminium trihydrate), etc.
As transmission and distribution applications such asinsulators work under the severest conditions theyrequire a very resistant material. Apart from all thegeneral advantageous properties of silicone rubber oneof the most demanding property requirements istracking resistance. T&D HTVs exhibit trackingresistance of 3.5 kV to 4.5 kV without a problem. As areference, standard HTV allows for 2.5 kV only.
Further, these materials have excellent resistance to anelectric arc and they are highly flame retardant. Also,as silicone rubbers are UV stable, they are the perfectmaterial for outdoor applications, which is documentedby experience over the last 30 years.
7.5 Addition Cured HTV
7.5.1 Introduction
One of the most prevalent disadvantages between HTVand LR has been the speed of curing because of thefaster crosslinking reactions for the LR compared toHTV. By changing from peroxide to addition curedHTV this difference has been compensated for or atleast diminished.
A further motivation for the increased use of additioncured HTV rubbers were the pharmaceutical
requirements, which have become stricter with respectto peroxide split products. Recently, the peroxides havebeen under discussion in Europe, as per likely changesto regulations, in particular for extrusion.
Another asset of the addition curing technique is the factthat it allows for nearly smell free production withoutany residual split products of peroxides. Consequentlythe as cured articles are considerably cleaner.
In addition, their appearance is more sterile, as they donot yellow, and their surface is much drier. The latteralso accounts for less stickiness between the siliconeparts themselves and also for better demouldingproperties.
Addition curing HTVs have more advanced mechanicalproperties as shown in a direct comparison to peroxidecuring HTVs in Table 50.
This table also indicates a remarkably lower modulusat equal Shore A hardness (this can be guessed fromthe elongation at break versus tensile strength).Behaviour like this is typical for addition cured HTVin moulding and extrusion.
7.5.2 Addition Curing
A distinction is made between one component and twocomponent systems. One component systems can beconsidered as mixtures of the two component systems(however the ingredients of the mixes have differentadditives and proportions).
One component (1K) systems have a shelf life of 3 to6 months, whereas the mixes of two components (2K)last for 1 to 7 days.
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Silicone Elastomers
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Table 51 gives examples of addition cured HTV gradesfor extrusion and mouldings, the mixing proportionsof the curing systems and some remarks.
7.5.3 Moulding: 1K Addition Cured HTV
This group of materials represents one of the latestdevelopments in silicone rubber technology. It goeswithout saying that it is quite contradictory if one wantsto have a fast curing material while having to stabilise itsuch that it does not cure at room temperature too quickly.
This has been achieved by using novel technology forsilicone rubber formulations. 1K HTV has alsodeveloped from the idea that processors want a ready-to-use compound, which they can put into the stufferbox of the injection moulding machine or the press.
Time and consequently cost pressure led them todemand a faster cure without increasing the complexityin the processing by having to mix a multi-componentsystem (the latter with a shorter pot life).
Essentially two product series have developed. Thefirst complies with most standard applications knownfor peroxide cured and organic rubbers. The second,a high tear strength series, has been designed to copewith advanced requirements in respect of tear andtensile strength.
Remarkably interesting is the fact that 1K HTV allowsfor the same speed of curing as the equivalent 2K HTV,as shown in Table 52. This table also shows thedifference in curing time of peroxide cured HTV andaddition cured LR.
As also mentioned under the upcoming processingsection, HTV rubber is available in pelletised form(however, there are a few restrictions). For the firsttime in the history of silicone rubber, this preform ofHTV allows for a fully continuous feed not only intoextruders but also to injection moulding machines. Thelatter has been a breakthrough in HTV technology, and,with addition curing and mould technology, HTVprocessing can be simplified as follows:
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Silicone Elastomers
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• Fully automatic,• Waste free,• Short cycles.
This results in low cost per piece. Thus this HTV ismuch more competitive to organic rubbers and evenLR. Such production methods have been demonstratedby LWB and Maplan.
For example, an injection moulded tubing connectorwith a length of 10 cm, inner diameter of 4 cm andwall thickness of 7 mm requires a curing time of only50 seconds, while needing 180 seconds at 180 °C withperoxide cured rubber (and, of course much longer withorganic rubbers). A 200 t ENGEL machine with aspecial feeding system for pellets was used in this test.
7.5.4 Moulding: 1K Self Adhesive AdditionCured HTV
It has been possible to develop a self adhesive HTV whichis addition curing and also a one component material. Itsticks to many more substrates than self adhesive LRs do(while not sticking to the mould, see Figure 13).
The main intention is to provide a self adhesive materialwhich allows for rubber to metal adhesion, easily.
As with self adhesive LR this material does not requirea primer on the substrate. All the processor has to do
is degrease and dry it before applying this novelsilicone rubber.
7.5.5 Moulding: 2K Addition Cured HTV
Some processors prefer 1 component systems allowingfor a storage time of at least 3 months at roomtemperature.
Others, however, prefer to buy two separatecomponents which they can put on the shelf over ayear and mix them, when needed. At this point, theyhave to pay attention to pot life.
Anyhow, both concepts have their pros and cons, and Iwill try to elaborate them in this subsection in Table 53.
In general, 2 component materials will provide moredegrees of freedom with respect to the internal logisticsof a processor: components have a very long shelf life,and there is an increased flexibility as to colour additionand hardness adjustments.
As with peroxide cured materials a mix of two gradeswith different hardness will result in an intermediatevalue. The relation between the mixing ratio and theresulting hardness is almost linear, as shown inTable 54. The hardness of peroxide curing siliconerubbers can be adjusted in the same way.
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Silicone Elastomers
56
By using a 2 component system with a mixing ratio of100:1.5 or 100:2 the processors gain further flexibility.Firstly because of more convenient stock management.Secondly, in order to achieve an intermediate hardnessit is necessary to mix two large components (insteadof 4 as in the case of 1:1 systems). This becomes ofmore importance when the processor has to mix twodifferent viscosities. Thirdly, it is easier to control thetemperature of the mix.
In comparison to peroxide cured HTV, mouldableplatinum cured HTV silicones cure twice as quickly(in most applications). Hence, the process requires lessenergy per piece.
7.5.6 Extrusion HTV
As with peroxide cured HTV, the curing speed has tobe much faster for extrusion than for moulding in orderto allow for sufficient cure.
This is necessary, as the uncured extruded profile hasto remain in shape while passing through the curingtunnel. This shape stability is the green strength. Asthe temperature of the material rises while passingthrough the curing tunnel its viscosity drops. The greenstrength of the material could be destroyed by this drop.A quick speed of curing acts against the drop inviscosity, and it thus assists the stability of the shapeof the extruded goods.
7.5.7 Post Curing of Addition Cured HTV
It is essential for processors to pay attention to the factthat addition cured products must not be post cured (insome cases not even stored closely) together withperoxide cured extrusions or mouldings. This can leadto discoloration, smell and in extreme cases to severedamage to the HTV articles (the latter if stored inhermetic packaging).
8 Processing Silicone Elastomers
Because of the wide variety of industries and the vastnumber of different silicone elastomers, it is notpossible to describe all the processing techniques. I willconcentrate on the most well established processingtechnologies for groups of materials in order to give acomprehensive picture.
Especially in recent years, processors have developedmore and more ideas about how to process silicone
elastomers, which allows us to predict that there will bemany new processing technologies within the near future.
All silicone elastomers should be stored at moderatetemperatures, i.e., between 15 and 30 °C. It is notadvisable to keep the stock of silicone elastomers outsideof shop floors. During hot periods this leads to shortenedshelf life. Too cold a storage leads to condensation ofwater and thus undesired impact on reactivity.
8.1 RTV-1 Systems
RTV-1 materials are supplied in tubes, cartridges, pails,drums and bags. Basically they are pumped from thepackaging and applied as indicated on process guidesand data sheets.
It is imperative to pay attention to the fact that the curingspeed will revert into depolymerisation at 80 °C orhigher, and, that the user must allow for sufficient contactwith ambient air and in particular moisture. This moistureis an essential reactant during the curing step andtherefore indispensable.
Most materials are pumpable manually or automatically.They are applied by robots and/or spreading systems.
Organic solutions of RTV-1 in apolar solvents are easilysprayable.
In order to achieve maximum adhesion when using RTV-1 as adhesives, there must be intimate contact betweenthe glue and substrate(s).
The technical documentation contains hints onprocessing time, pot life and/or skin forming time. Theindustrial application process has to be chosen such thatprocessing occurs well before expiry of these processwindows.
It is highly advisable to take into account the fact thatmost of the stated properties of the cured rubbers developa couple of days after the cure to a tack free state. Thishas to be checked and implemented in the design of theapplication process prior to mass production.
8.2 RTV-2 Systems
For RTV-2 systems basically the same process guidelinesapply as for RTV-1. However, being 2 componentsystems much shorter processing times are possible.
In both RTV-1 and RTV-2 processing it is vital tomaintain a constant temperature relevant to the process
Silicone Elastomers
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step. The same holds for the humidity in the case ofcondensation curing materials.
The mixing ratios allow for certain tolerances in termsof process characteristics. However, an excess or lackof the components leads to varied speed of curing,embrittlement, stickiness, no cure and the like. Thus itis advisable to provide the correct mixing ratios byaccurate operating instructions and personnel training.
It is also vital to take into account differences in viscositiesof the single components. Low viscosity materials tendto stick to the wall of the mixing vessel which can lead todosage errors. Also thin liquids are best mixed into highviscosity media and not the other way round.
Uncured paste-like silicone RTV-2 components cancontain up to 20% dissolved air, especially if thecomponents are pumped by pressurised air. In suchcases the processor has to take care to deaerate thembefore use, particularly, if the curable mix is heated inorder to speed up the curing process. Incompletelydeaerated systems tend to form bubbles.
The processing of RTV-2 materials could be describedad infinitum, because RTV-2 processing includes manydegrees of freedom and many products. It is impossibleto explain everything in one go. The reader is stronglyencouraged to refer to literature on the raw materialsand also to documentation as supplied by equipmentmanufacturers.
Mould making will be described as an example of thecomplexity of processing.
8.2.1 Mould Making: Flexible Moulds
Mould making (flexible moulds) consists of thefollowing steps (a.10):
• Make and prepare a model,
• Get raw materials ready (single components),
• Meter and mix the components,
• Deaerate the mix (air is entrapped after storage andduring mixing),
• Make the mould.
In order to prevent sticking problems the model surfacehas to be free of porous, moisture absorbing (condensationcuring systems!) and silicone/silicate containing surfaces(in particular ceramics, glass, etc.). This can be done bycoating the model with polyvinyl alcohol, methylcellulose, soft soap or Vaseline.
In the case of addition curing RTV-2 systems one has totake care that the model does not inhibit the cure.Otherwise one has to apply a coating to the model.
It is highly advisable to thoroughly stir pourable RTV-2silicone rubber components prior to their use torehomogenise them. The same has to be done withcomponents that have high viscosity with high mechanicalproperties.
The components should be dosed accurately. Variousequipment can be used in metering. Again the equipmentmust be free of inhibitors if addition curing materials areto be processed.
The mix must be homogeneous in order to ensure uniformcuring characteristics.
Pourable and spreadable products can be mixed by handwith a spatula or, for larger amounts, with a mechanicalstirrer or automatic mixing and metering equipment (thelatter can be fully automated). Kneadable compounds aremixed on a triple roll mill or in a kneader.
To obtain vulcanisates without any air bubbles, pourablegrades have to be deaerated in a desiccator or vacuumcabinet at reduced pressure.
Spreadable, non sag and kneadable mixes cannot easilybe deaerated. In this case, first a thin, bubble-free primerof a pourable grade is applied to the surface of the modelfollowed by the spreadable or kneadable compound.
Flowable RTV-2 silicone rubbers are poured over themodel, spreadable and non sag compounds are appliedusing a spatula. Kneadable grades in the form of a sheetare pressed on the model surface by hand or using a roller.
With flexible silicone moulds, undercuts can bedemoulded by stretching the mould.
Apart from the versatile properties of silicone elastomers,RTV-2 silicone has advantages over organic elastomersin mould making:
• Easy processing,
• Extremely flexible when cured and durable,
• High strength grades are available, which are tearresistant,
• Excellent release properties, and
• Relatively safe raw materials compared with, e.g.,polyurethanes.
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8.2.2 Mould Making: Block Moulds
One part block moulds are normally used to copysingle sided objects such as stucco, coins, etc. Themodel is put into a box and covered using flowablesilicone, or, it is impressed into a block or strip ofkneadable silicone rubber.
This is related to spin casting.
It is possible to cut the ready made mould along aparting line in order to allow for better demoulding.These multipart moulds are advantageously made fromtransparent silicone rubbers. Two-part block mouldscan be made by pouring a one-part block mould andcutting it open along a parting line.
8.2.3 Mould Making: Skin Moulds
For large models or ones with deep undercuts, a skinmould is the choice with 5-10 mm thickness.
Skin moulds require less material but they are labourintensive. Thus the mould maker has to assess theeconomics of each moulding job.
Skin moulds result from pouring or spreadingtechniques. Smaller horizontal models are best copiedusing the pouring method.
The model is covered with clay or plastilline. Thethickness of the spacer determines the thickness ofthe skin mould. The rigid layer is put on top of thespacer. It is poured (plaster or casting resin) or spreadin a few layers (polyester, polyurethane or epoxyresin, etc.). After curing it is separated from thespacer. The latter is no longer needed. The supportcontaining air vents and feeding holes is now putover the model. The silicone rubber is fed throughthe feeding hole and left until it is entirely cured.After demoulding the model and recombiningsupport and mould, the skin mould is ready to receivethe reproduction material.
Too large or vertical models are reproduced by thespreading technique. This is a layering method, asdescribed before. A thin primer of pourable siliconerubber is applied to the model. This primer guaranteesthe copying of fine details of the model. After a partialcure a top layer of non sag silicone rubber is appliedusing a spatula. The support consists of fabric stripssoaked in plaster or a fibreglass-reinforced organicresin. The demoulding stages are identical to those ofthe pouring technique.
8.3 LR and HTV
8.3.1 Press Curing HTV
In press curing the processor preforms HTV into piecesof the required size and puts them into a hot mould.The two halves of the mould are mounted in a hydraulicpress. The press closes and the curing takes place. Afterthe cure the processor demoulds the parts manually.
As a post treatment he has to remove flash, which is aresult of internal mould pressure and to check the partsfor incomplete cure, which is particularly important inperoxide cure technology.
In press or compression moulding the processor has toput silicone rubber pieces into each cavity.
8.3.2 Transfer Moulding HTV
In transfer moulding the mould is equipped with areservoir into which the processor puts the rubber.Ideally the temperature of the reservoir is well regulatedwhile not affecting the thermal balance of the mouldwhich is located below it.
The transfer process has the advantage of being ableto provide silicone rubber to multiple single cavitiesand also to fill moulds that have long flow paths.
In transfer moulding one would typically use the samepress as for compression moulding.
Both, transfer and press moulding are processingtechniques most suitable for small series production(or mass production with a wide variety of geometries).However, press curing and transfer moulding will notcompete with injection moulding, if it gets to largerscale production.
Mould design in these two technologies is less criticalthan in injection moulding. But it is well known thateven in these basic technologies of silicone HTVprocessing it is a must to obey the ‘rules of silicone’by applying the correct conditions. In many discussionswith processors these conditions have improved themoulding result upon changing these parameters:
• Moulding temperature (not below 160 °C, ideallyat 180 °C),
• Clamping force (as high as possible, variable),
Silicone Elastomers
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• Mould surface (electroeroded, sand or glass pearlblasted; a smooth or polished surface increasesstickiness),
• Mould release agents ONLY if necessary,
• Internal mould release agents to be avoided wherepossible,
• Volume of the parts to be balanced with the forceof the press.
8.3.3 Injection Moulding LR and HTV
Injection moulding technology easily outdoes the twolatter moulding techniques. It allows for fully automaticprocessing with essentially no need for personnel. Thus,the human factor is negligible in the outcome of theprocessing, or at least it is constant, if the settings ofthe injection moulding machine are kept constant.
As in most fully automatic processes the technicalrequirements for the moulds are stricter than in theprevious cases.
8.3.3.1 Injection Moulding HTV
In the case of HTV an injection moulding machine isfed via a piston (up to 25 l) which presses the siliconerubber into the barrel of the machine. The screw of themachine takes in the required injection volume whilemoving backwards. When finished the screw is pushedforward and this volume is injected into the mould.
In order to avoid back flow of the material the tip ofthe screw is equipped with a check valve. The nozzleof the barrel has a needle shut off valve.
As the rubber cures at elevated temperatures it shouldbe kept as cold as possible during the injection. This iswhy a good injection moulding machine allows forgood temperature control of the rubber during themetering and injection steps.
If the temperature control becomes inefficient, e.g.,because of frictional heat, the injected rubber couldstart to cure prematurely, resulting in filling defects.Hence, it is essential to keep the rubber cold as long aspossible during injection while it should cure as quicklyas possible after filling the mould.
This is achieved by using a cold runner system. This isa manifold which distributes the curable HTV rubber
directly to the single cavities. The cold runner istemperature controlled up to the tips of the nozzles ofthe manifold system. It goes without saying that it isdifficult to design such mould concepts as it is notobvious how to apply cold nozzles hermetically to hotcavities. This is the trick and the know how of the mouldmakers. The hot mould is at 170 to 220 °C. Theinjection volume is kept at room temperature and insome cases up to 60 °C (the latter only in the case ofperoxide cured HTV) in order to reduce viscosity. Thecold runner will typically heat up to approximately40 °C. The nozzles of the cold runner are either openor needle operated.
The injected volume trapped in the cavities heats upwhile having time to cure. As the silicone heats up italso expands. This is why it exerts an internal pressureto the surface of the mould of up to 500 bar. Thispressure has to be compensated for by the clampingforce of the injection moulding machine. Oversizedmoulds (too many cavities and/or too high a cavityvolume) result in defective parts.
The feeding of HTV into the piston (stuffer box) ofcourse is in contradiction to a fully automatic process,particularly if we also consider the fact that the rubberbase has to be mixed with the curing additives on rollermills before being charged. Using advanced mouldingtechnology it is possible to process HTV rubberscompletely waste free and fully automatic between twocharging cycles. Now, these charging cycles may nolonger be relevant.
Injection of HTV is at a revolutionary stage ofdevelopment at the moment. HTV is now available inpellet form. Figure 14 shows the concept of the feedingsystem which prevents bridge formation (thus blockingby electrostatic charge of the HTV pellets). It is possibleto feed the pellets over distances of 20 m out of boxesor vessels of almost infinite size. As a consequence,no storage space is necessary close to the machine.
The processing is further facilitated by the fact that itis possible to add pelletised colour masterbatches.
8.3.3.2 Injection Moulding LR
Liquid silicone rubber has a much lower viscosity thanHTV. This is why the strict requirements as to mouldtechnology are even stricter for LR. The tolerancesalong parting lines have to be as low as possible. Atthe same time, as the speed of injection is much fasterthan with HTV and the viscosity much lower, thecavities have to allow for removal of air.
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Furthermore, LR moulds have to work fully automaticupfront, in order to allow for the desired productivity.Because of the speed of curing one also wants toincrease the number of cavities in order to allow for amaximum number of parts per cycle (today it is possibleto produce up to 256 parts per shot).
All these needs and properties require an utmost degreeof experience in machinery and mould design. Thereare approximately 10 mould makers worldwide whoknow how to construct competitive moulds for LR.
As to machinery, the number of machinery suppliersbeing as small or smaller, the requirements are stricteras well. Because of the increased speed of curing onehas to pay attention to the thermal regulation. The lowviscosity requires specially constructed check valvesat the tip of the screw.
Because of their curing mechanism liquid siliconerubbers are two component systems. LRs are suppliedas two components with a mixing ration of 1:1. Specialpumping units pump the material from drums into astatic mixer, which leads the curable mix into the barrelof the injection moulding machine.
As in HTV the cold runner will consist of a wellbalanced manifold system with open or needle shut offnozzles. The maximum numbers of cavities are 256 or64, respectively.
The processing system essentially consists of apumping unit ensuring a 1:1 mixing ratio of A- and B-components (where component A contains the Ptcatalyst and B the Si-H crosslinker), the injectionmoulding machine (using a static mixer the 1:1 A andB flows result in an intimately mixed curablecomposition) and a cold runner mould for liquid rubber.
In quiescent state the AB mix and also the singlecomponents have a paste like consistency. Theirviscosity typically ranges from 100 to 8,000 Pas. Oncesheared the viscosity drops dramatically. Hence, whenpumped the viscosity drops by a factor of 2-4, wheninjected through the cold runner nozzles the materialturns into a liquid with a consistency of syrup.
This consistency allows for the use of injectionmoulding machines with a relatively low clampingforce. Preferably this is between 80-100 tons. However,special applications such as high volume articles witha high projected surface require up to 400 tons.
The low viscosity also favours long flow paths andcomplex geometry, the latter with very precise tolerances.
Figure 15 describes the processing system. The mouldsymbol comprises the cold runner and the hot mould.The material is kept relatively cool until the end of thecold runner, when it enters a hot mould.
Figure 14
Feeding system for HTV pellets as used in moulding and extrusion
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The cold runner acts a manifold that allows for thetransport of the liquid material directly to the cavities.Its task is to keep the material cold until it enters thehot cavity through the nozzle which is also cooled. Inthe market for liquid silicone rubber moulds such coldrunners can manage up to 128 cavities. The nozzlesare either open, or equipped with needle-shut-offvalves. Both concepts are widely used and each has itspros and cons.
It is highly advisable that interested processors contactmould makers specialising in LR processing. Basedon drawings and article specifications they provide thebest information as to:
Thermal separation between cold runner and hotmould,
Heating of the mould (this is usually insufficientin less experienced mould makers),
Balancing the cold runner manifold in order toprovide uniform flow and thus mould filling,
Numbers of cavities,
Mould design, LR allows for flash free productionwith no waste at all,
Allowing for thermal shrinkage of LR (as shownin Figure 16, please note this is also considerable
when designing HTV moulds!), tolerances, andventing during the filling stage,
Selection of steel quality. It is essential to use thecorrect steel which allows for proper demouldingand life time of the mould,
Spare parts and after sales service,
Training,
Selection of the machine size or adaptation to agiven machine specification,
Demoulding and other automation aids such asrobots, etc.,
They sometimes also offer packages includingeverything.
It goes without saying that processing liquid rubber isnot possible with a machine that is used for thermoplasticinjection and/or high consistency rubber. The machinerysupplier must be prepared to provide a so-called LIM(liquid injection moulding), package. A typical technicalterm in this respect is therefore ‘LIM machine’.
As mentioned before, there are a few machine suppliersthat would be able to provide the knowledge as statedabove for mould makers. It goes without saying thatexperienced machinery and mould makers maintainrelationships which prove productive in each project.
Figure 15
Processing of liquid silicone rubbers
Mode of operation of an injection moulding machine.
ELASTOSIL® LR is suitable for virtually all meteringand mixing equipment,
1 Metering device for Components A and B of theliquid silicone rubber
2 Metering device for pigment (if required)
3 Mixing device
4 Mould
5 Heated injection mould with injection moulding part
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8.3.4 Extrusion of HTV
The major processing techniques of solid siliconerubber are 60% extrusion and 40% moulding. Alesser amount is used in calendering and textilecoatings.
In extrusion, catalysed solid silicone rubber is fedinto an extruder designated for silicone processing.Ideally the screw has a core and/or flight progression.As the screw fulfils various tasks such as feeding,deaeration, residual mixing and replastification (thelatter is of importance, e.g., in the use of siliconerubber pellets) it must have an L/D ratio of 12 to 18.
a) Extruder
The extruder should be well thermally regulated toambient temperature. Its design should allow for easychanges of nozzles and filter screens and its head(and nozzle) should be coolable.
For cable extrusions and multilayer extrusions (suchas in fabric reinforced hoses) the extruders areequipped with so-called cross heads. Ideally anysilicone extruder should include an option for thisset up.
The drive of the extruder should allow for a widerange of rpm. Torque, pressure and temperaturereadings have proven to be useful.
b) Curing tunnel
Most typically the curing furnace or tunnel ishorizontal. It is equipped with a conveyor belt for thetransport of the extruded profile.
If it is essential to produce profiles without any beltmarks, one has to use a shock oven (approximately50 cm long, up to 850 °C) that quickly cures the outerskin of the profile in front of the furnace.
Figure 17 shows a scheme of this set-up. It is importantthat the furnace is long enough, with a wide range oftemperatures, and good and homogeneous heat transferand distribution.
In the case of both the shock zone and the curingtunnel it is highly advisable that a minimum ofirradiation heat gets to the extrusion die. Thisminimises scorch and allows for ideal control ofmaterial viscosity. The latter – this is obvious butimportant – is a function of temperature.
8.3.5 Moulding HTV (General)
Most typically mouldable HTV silicone rubbers areprocessed by press curing, transfer or injectionmoulding.
The typical curing temp is between 170-200 °C.
Figure 16
Linear shrinkage of LR (ELASTOSIL® LR 3003/50) as a function of moulding temperature and flow directions(a) lengthwise, post-cured; (b) lengthwise, not post-cured; (c) broad-side, post-cured; (d) broad-side, not post-cured
Silicone Elastomers
63
In order to facilitate demoulding, the mould surfacesneed treatment. In many cases it is sufficient to use adetergent or an internal release agent as an additive tothe formulation of the silicone rubber.
In more sophisticated moulds special surface structureslead to desired moulding results. C1 and C6 typicallyare the peroxides used in moulding applications. Foraddition curing moulded parts one has to apply therespective addition curing moulding grade, and forextrusion, a special extrusion grade. In extrusion andmoreover in the following section dimensional stabilityand mechanical strength are important even before thecure of the product.
8.3.6 Calendering HTV
Some solid silicone HTV rubbers are designed forprocessing by calendering. During calendering siliconerubber passes through 3 or more rollers while beingformed into a strip. Often calendering is used forpreforming rubber strips on fabrics or just simple stripswhich then cure.
Often it is important to use a so-called high greenstrength rubber which allows for sufficient mechanicalstability of the uncured strips. Such high green strength
rubbers (e.g., ELASTOSIL® R 760/60-70) not onlyexhibit high stability of strips, they would also be goodmaterial for extrusion. Thus a high green strengthusually means good extrudability. One of the measuresfor high green strength are the viscosity parametersWilliams plasticity and Mooney viscosity. However,as in calendering the high green strength behaviour ismore a result of elongation flow (strips are pulled),there is no direct parameter that would fully describehigh green strength behaviour.
Table 55 gives a comparison of standard siliconerubbers versus high green strength silicone rubbers andtheir preferred use.
Fabrics need pre-treatment with primers before coatingwith silicone rubber strips in order to provide goodadhesion between rubber and fabric. Different primersare required for different elastomers and substrates.
The fabrics can be coated with solvent containingprimers. The application is such that the fabric is coatedwith the primer by immersion, painting, spraying, etc.After drying off the solvent it is advisable to cure theprimer at approximately 130 °C for say 10 minutes.
The primers must be protected from moisture. As aconsequence it is essential to apply them onto a dry ordried fabric.
Figure 17
Extrusion line for HTV
VTHsrebburenocilisdilossuoiravforuoivaheb)SGH(htgnertsneerghgihfonosirapmoC55elbaT
epytlairetaMLISOTSALE( ® )edarG,R
ytisocsivyenooM)eulavdne;tratS(
yticitsalpsmailliW noitacilppA
dradnats,07/104 06;66 313 esopruplareneG
SGH,06/204 65;95 872 noisurtxE
SGH,57/204 27;18 203 noisurtxE
SGH,07/067 86;17 004 noisurtxe,gnirednelaC
Silicone Elastomers
64
Another technique is to apply a so-called adhesive basewhich is previously calendered onto the fabric in therequired thickness. The adhesive base allows extremelyhigh adhesion. Cohesive failure is often found in tests.It is popular to use the adhesive base in the manufactureof rollers.
A more detailed description of primers is beyond theintended scope of this article (see a.11, a.12, andtechnical bulletins from material suppliers).
One of the most prominent examples of applicationsfor calendered goods is fabric reinforced hoses as oftenused in the automotive industry. Such hoses are usedas coolant or turbocharger hoses (the latter are verysophisticated composites). The calendered HTV/fabricstrips are wrapped in layers around preformedmandrels. The outer layer is then protected with abandage of, e.g., polyethylene terephthalate (PET).
For pressureless curing one can use crosslinker E.However, typically one uses C1 or C6 with bandagesprotecting the catalysed rubber from contact withoxygen. The curing takes place in steam autoclaves.
8.3.7 Rollers
The components of rollers are an elastic silicone rubberlayer which adheres to a solid metal or plastic core.Again, one can use a primer or a special adhesive baseto provide the adhesion between solid/elasticcomponents.
Rollers are cured with crosslinkers C1 or C6, as thecompression set is much lower than in the case ofcrosslinker E. The same bandages apply for rollers asin case of calendering.
After curing in a steam autoclave the bandages areremoved, and the roller surface gets its final finish bygrinding.
8.3.8 Bonding
Composites of hard and soft materials such as thepreviously mentioned rollers and calendered articlesoften require adhesion between substrate and silicone.Silicone rubber bonding has been reviewed (a.11).
The most spectacular developments in the recent pastrefer to self adhesive technology.
Self adhesive silicone rubbers are demouldable (withthe exception of adhesive bases) while sticking to thesubstrate.
For rubber to metal applications the latest developmentis an addition cured one component solid siliconerubber. It cures rapidly and adheres well to steel andvarious plastics.
9 SUMMARY
The versatility of silicone elastomers is enormous,which is why this review has only covered the majorapplications, groups of materials and the mostimportant processing techniques.
Textile coatings have been mentioned as an extra fieldof applications. This field and some others would againfill an article of this size.
The beauty of silicone elastomers is that they showmany advantages over organic rubbers, such as easyprocessing, much shorter processing times, andimproved physical and chemical properties. Just bytheir appearance and pigmentability, their inert andbiocompatible compositions, silicone elastomers havea great number of future applications. Because of thesefeatures silicone elastomers are being used to substituteorganic rubbers.
Silicone elastomers are special: there is no othermaterial exhibiting a similar spectrum of propertiesbecause of the silicone chemistry. The behaviour is notentirely inorganic and not entirely organic. Thestructure of a polydimethyl siloxane is apolar andchemically quite inert. Silanes and silicones undergochemical reactions by laws that are different to thoseof organic molecules. It took the industry more than50 years of the last century to characterise thischemistry and use it in elastomers.
The seemingly small material family of siliconeelastomers will continue to develop in variety ofmaterials, innovative individual types and specificadvantages in processing. For example, 10 years agonobody would have expected HTV rubber to be availablein pellet form, to allow fully automatic processing andwith no need for secondary treatment because the curingsystem has such a low level of emissions.
Who would have thought that there could be a selfadhesive silicone elastomer that would stick to substrates
Silicone Elastomers
65
when moulded while not sticking to the mould? The latterwould not even require a release agent!
One can predict many such surprises as siliconeelastomers develop further. Innovations will strengthenand complement current advantages and will contributeto many different problem solutions. For example,saving energy, protecting the environment, savinghuman lives, and, of course, much more.
ADDITIONAL REFERENCES
a.1 W. Noll, Chemistry and Technology ofSilicones, Verlag Chemie, Weinheim, 1968.
a.2 A .Tomanek, Silicone und Technik, Wacker-Chemie, Carl Hanser, Munich, 1990.
a.3 UL2196, Tests for Fire Resistive Cables,2001.
a.4 UL94, Tests for Flammability of PlasticsMaterials for Parts in Devices andApplications, 1996.
a.5 ISO 4589, Plastics – Determination ofBurning Behaviour by Oxygen Index, 1996.
a.6 ASTM D 2863, Standard Test Method forMeasuring the Minimum OxygenConcentration to Support Candle-LikeCombustion of Plastics (Oxygen Index),2000.
a.7 BS 6853, Code of Practice for FirePrecautions in the Design and Constructionof Passenger Carrying Trains, 1999.
a.8 K. Wieczorek, High Performance Elastomers2000, Berlin, Germany, 2000, Paper 10.
a.9 ASTM D624-00e1, Test Method D624-00e1Standard Test Method for Tear Strength ofConventional and Vulcanized Rubber andThermoplastic Elastomers, 2000.
a.10 G. Kollmann in Organosilicon Chemistry IV,Ed., N. Auner and J. Weis, Wiley-VCHWeinheim, 2000, 710.
a.11 P. Jerschow and W. Strassberger in Handbookof Rubber Bonding, Ed., B. Crowther, RapraTechnology Ltd., Shawbury, UK, 2001, 287.
a.12 P. Jerschow, Rubber Bonding 2000,Amsterdam, The Netherlands, 2000, Paper 14.
ABBREVIATIONS ANDACRONYMS
BgVV Bundesinstituts für gesundheitlichenVerbraucherschutz und Veterinärmedizin
C1 Dicumyl peroxide
C6 2,5-(bis-t-butylperoxy-)-2,5-dimethylhexane
CIPG Cured-in-place-gasket
CS Compression set
E 2,4-dichlorodibenzoylperoxide
ECU Electronic control unit
EPDM Ethylene-propylene terpolymer
EtO Ethylene oxide
FDA US Food and Drug Administration
FIPFG Formed-in-place-foamed-gasket
FIPG Formed-in-place-gasket
GMP Good manufacturing practice
GP General purpose
HCR High consistency rubber
HGS High green strength
HTV High temperature vulcanising, solidsilicone rubber
IC Integrated circuit
LIM Liquid injection moulding
LOI Limiting oxygen index
LR Liquid rubber
LSR Liquid silicone rubber
MEG Monoethylene glycol
NPC No post cure
NR Natural rubber
PA Polyamide
PBT Polybutylene terephthalate
PC Post cure
PC Polycarbonate
Silicone Elastomers
66
PDMS Polydimethyl siloxane
PET Polyethylene terephthalate
PF Phenol-formaldehyde resin
PMMA Polymethyl methacrylate
POM Polyacetal
PP Polypropylene
PPE Polyphenylene ether
PPO Polyphenylene oxide
PPS Polyphenylene sulfide
PU Polyurethane
PVC Polyvinyl chloride
RTV Room temperature vulcanising
RTV-1 Room temperature vulcanising, onecomponent
RTV-2 Room temperature vulcanising, twocomponent
T&D Transmission and distribution
t90 Time needed to reach 90% vulcanisationunder isothermal conditions
TPE Thermoplastic elastomer
UL Underwriters Laboratory
UV Ultraviolet
VDE Verband Deutscher Elektrotechniker
XLR® Extra liquid rubber
References and Abstracts
© Copyright 2001Rapra Technology Limited 67
References from the Rapra Abstracts Database
Item 1Patent Number: EP 1106654 A2 20010613
SILICONE RUBBER COMPOSITION KEYPADSSugimoto S; Sato T
Dow Corning Toray Silicone Co.Ltd.
The above composition comprises a silicone rubber base
produced by mixing under heat (A) a crosslinkable
diorganopolysiloxane and (B) 20 to about 250 parts by
weight calcium carbonate powder per 100 parts by weight
of component (A), and (C) a curing agent consisting of
(i) an organic peroxide or (ii) an organohydrogen-
polysiloxane and a platinum catalyst in an amount
sufficient to effect cure of the composition.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.818527
Item 2Revue Generale des Caoutchoucs et Plastiques
77, No.790, Nov.2000, p.68-9
French
ENGEL: THE PLASTICS TRUMP CARDDelannoy G
An account is given of developments by Engel in injection
presses, including vertical and horizontal machines for
rubber moulding, special machines for the processing of
silicone rubbers, and machines for use in multi-material
moulding.
ENGEL; ENGEL FRANCEAUSTRIA; EUROPEAN COMMUNITY; EUROPEAN UNION;
FRANCE; WESTERN EUROPE
Accession no.818407
Item 3Patent Number: US 6184260 B1 20010206
METHOD FOR MAKING NANOPOROUSSILICONE RESINS FROMALKYLHYDRIDOSILOXANE RESINSZhong B
Dow Corning Corp.
A method for preparing a nanoporous silicone resin which
can be used to form low dielectric constant films useful
for electrical insulating coatings on electronic devices
comprising (A) contacting a hydridosilicon containing
resin with a 1-alkene comprising about 8 to 28 carbon
atoms in the presence of a platinum group metal-
containing hydrosilation catalyst effecting formation of
an alkylhydridosiloxane resin where at least 5 percent of
silicon atoms are substituted with at least one group
comprising about 8 to 28 carbon atoms and at least 45
percent of silicon atoms are substituted with at least one
hydrogen atom and (B) heating the alkylhydridosiloxane
resin of step (A) at a temperature sufficient to effect curing
and thermolysis of alkyl groups comprising about 8 to 28
carbon atoms from the silicon atoms thereby forming a
nanoporous silicone resin.
USA
Accession no.817427
Item 4Journal of Sol-Gel Science and Technology
21, No.1/2, June 2001, p.75-81
BIOACTIVITY AND MECHANICALPROPERTIES OF POLYDIMETHYLSILOXANE(PDMS)-CAO-SIO2 HYBRIDS WITHDIFFERENT PDMS CONTENTSKamitakahara M; Kawashita M; Miyata N; Kokubo T;
Nakamura T
Kyoto,University
Hybrid materials were synthesised by a sol-gel process frompolydimethylsiloxane (PDMS), calcium oxide, and silicon
dioxide as potential bone replacement materials. They wereinvestigated for their surface apatite formation and releaseof silicon in simulated body fluid, and subjected to Fouriertransform infrared spectroscopy, thin film X-ray diffraction,and three-point bending mechanical tests. The surfaceformation of apatite is a measure of the materials ability to
bond to bone in situ. The surfaces were examined byscanning electron microscopy. The material with PDMS :tetraethoxysilane (TEOS) + PDMS weight ratio 0.3,calcium nitrate : TEOS molar ration 0.15 and water : TEOSmolar ratio 2 showed high apatite-forming ability, lowsilicon release, and mechanical properties similar to human
cancellous bone. 26 refs.
JAPAN
Accession no.817314
Item 5Patent Number: EP 1090967 A2 20010411
COMPOSITION FOR FILM FORMATION,METHOD OF FILM FORMATION, ANDINSULATING FILMKurosawa T; Hayashi E; Youngsoon S; Konno K;
Shiota A; Yamada K
JSR Corp.
A polyorganosiloxane-based composition for film
formation, which gives a film having low dielectricconstant and high elastic modulus and which is useful asan interlayer insulating film in semiconductor devices,comprises (A) a product of hydrolysis and condensationobtained by hydrolysing and condensing, in the presenceof an alkali catalyst, at least one compound(s) of given
formulae and (B) a product of hydrolysis and condensationobtained by hydrolysing and condensing, in the presenceof an acid catalyst, at least one of the above compounds.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.817003
References and Abstracts
68 © Copyright 2001 Rapra Technology Limited
Item 6Rubber and Plastics News
30, No.21, 14th May 2001, p.12
DOW SILICONE SEALANT OFFERS UV,WEATHER RESISTANCE
Dow Corning’s 700 Industrial Grade Silicone Sealant has
been used by an unnamed car manufacturer to re-coat a
PVC-jacketed electrical cable that had faded and cracked
from weathering and exposure. Rather than replace the
cable, Dow Corning suggested the sealant as an alternative
remedy. After testing the adhesion and UV protection of
the silicone formulation, an industrial painting engineer
was employed to coat 7,200 feet of cable on the
automaker’s plant roof, saving the company about
400,000 US dollars. The sealant cures at ambient
temperatures to a tough, rubbery solid that is virtually
unaffected by UV light, ozone, rain and extreme
temperatures.
DOW CORNING CORP.USA
Accession no.816787
Item 7Rubber and Plastics News
30, No.21, 14th May 2001, p.11-2
FULL OF PROMISEMcNulty M
Silicone rubber has been popular in the automotive and
medical device industries for some time, but it is emerging
as a more commonly used material in the electronics,
aerospace, sealants, baby products and a wide assortment
of other markets. Annual growth is estimated at around
4-5%. NuSil Technology attributes the steady
improvement to several factors, including silicone’s
ability to perform well under extremes. Liquid silicone is
ideal for the healthcare industry because it is clean and
has the ability to withstand chemical and foreign body
contamination. The material has also benefited from fears
of allergies related to natural rubber latex. In the
electronics industry, silicone is used for coating systems,
electrically and thermally conducted applications and as
an insulating application.
USA
Accession no.816786
Item 8Patent Number: US 6177143 B1 20010123
ELECTRON BEAM TREATMENT OFSILOXANE RESINSTreadwell C; Yang J; Ross M
Disclosed are electron beam cured siloxane dielectric
films, which are useful in the production of integrated
circuits. A siloxane polymer having less than 40 mole
percent carbon containing substituents or at least
approximately 40 mole percent carbon containing
substituents may be cured by wide beam electron beam
exposure.
USA
Accession no.816249
Item 9Kunststoffe Plast Europe
91, No.4, April 2001, p.32-3
SILICONE BONDSKraibuhler H
Arburg GmbH
New injection moulding concepts are discussed which
have been instrumental in the increase in the use of
injection moulded silicone parts for technical applications.
Such developments include multi-component
applications, sprueless injection moulding, and economic
micromoulding thanks to new micro-metering units.
(Article translated from Kunststoffe 91 (2001) 4, pp.88-
89).
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.815269
Item 10Patent Number: US 6169142 B1 20010102
THERMAL CONDUCTIVE SILICONE RUBBERCOMPOSITIONS AND METHOD OF MAKINGNakano A; Hashimoto T
Shin-Etsu Chemical Co.Ltd.
Silicone rubber parts having a high thermal conductivity
and low hardness are obtained by moulding and curing a
composition comprising (A) 100 parts by weight of an
alkenyl-bearing organopolysiloxane having a viscosity of
up to about 500,000 centistokes at 25 degree C., (B) 300-
1, 200 parts by weight of aluminium oxide powder, (C)
0.05-10 parts by weight of an alkoxysilane of the formula:
R1a Si(OR2)(4-a) wherein R1 is a monovalent 6-20 C
hydrocarbon group, R2 is a C.sub.1-6 alkyl group, and
a=1, 2 or 3, (D) a platinum group metal catalyst, and (E)
an organohydrogenpolysiloxane containing at least two
SiH groups in a molecule. The composition is formulated
so as to suppress the viscosity increase of a liquid silicone
rubber composition due to heavy loading of aluminium
oxide.
JAPAN; USA
Accession no.815127
Item 11Rubber and Plastics News 2
22, No.13, 9th April 2001, p.3
WACKER-CHEMIE ADDS TO LIQUIDSILICONESBegin S
Wacker-Chemie has expanded its line of cost-saving, self-
adhesive liquid silicone rubbers. Last year the company
References and Abstracts
© Copyright 2001Rapra Technology Limited 69
finalised development of nine additional grades of
Elastosil LR for the automotive industry. The grades differ
according to their resistance to temperature, oil and
coolant. Elastosil LR is said to be ideal for overmoulding
thermoplastics and metal parts, in applications ranging
from exhaust pipe hangers and engine mounts to
multifunctional steering wheel switches, air regulator
membranes and automotive cables. Elastosil LR grades
incorporate an adhesion agent which slowly diffuses out
of the rubber and then sticks between it and the plastic or
metal during two-component injection moulding. Metal
and plastic substrates can remain unprimed, saving cost
and time.
WACKER-CHEMIE GMBHEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.814724
Item 12Patent Number: US 6159398 A1 20001212
METHOD OF MAKING REPLICAS WHILEPRESERVING MASTERSavant G D; Hosseini A
Physical Optics Corp.
An improved method of making laminated optical
components using a master and several submasters is
disclosed. A glass/photoresist master is made by recording
optical surface features in the photoresist with coherent
or incoherent light. The master is processed to reveal the
surface features. A frame is fastened to the edges of the
photoresist/glass master with edges rising slightly above
the top surface of the master. Silicone rubber is poured
into the frame over the photoresist layer and allowed to
cure. The silicone rubber submaster is then separated from
the photoresist/glass master. Use of silicone rubber
permits separation of the submaster without damaging
the master. Additionally, silicone rubber is less prone to
shrinkage than prior art submasters, thus permitting more
accurate copying of the surface features of the photoresist/
glass master. Subsequent epoxy replicas may then be made
from the silicone rubber submaster.
USA
Accession no.813549
Item 13Rubber and Plastics News
30, No.16, 5th March 2001, p.16-7
PLUG-LESS SILICONE GASKETS OFFER NEWWAY TO FIRE ENGINEBegin S
The advantages of a new gasket, called the Multiple Spark
Ignition Gasket, developed by Gasket King, are
highlighted. The gasket consists of a pre-ceramic silicone
rubber with fabric reinforcements and a wire ignition
system embedded in the middle of the gasket. Location
of a multiple spark in the gasket creates “surround
combustion”, an optimal method of burning fuel in an
engine’s combustion chamber. The gasket may be
retrofitted on current engines without major changes to
the engine and is expected to greatly minimise emissions
and increase fuel efficiency.
GASKET KINGUSA
Accession no.813046
Item 14Materie Plastiche ed Elastomeri
65, Nos.7/8, July/Aug.2000, p.560/9
Italian
PLASTICS THAT DENTISTS LIKEBaucia G
Applications of plastics, filled composites and silicone
rubbers in dentistry are examined with reference to
materials and product developments by a number of
companies. Dentists’ chairs and associated equipment
produced by Italian companies and incorporating plastics,
composite and PU foam components are also described.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE; WORLD
Accession no.812725
Item 15International Polymer Science and Technology
28, No.2, 2001, p.T/6-8
OIL BLEEDING BEHAVIOUR OF SELF-LUBRICATING LIQUID SILICONE RUBBERSPohmer K
Wacker-Chemie GmbH
The diffusion of silicone oil from self-lubricating liquid
silicone rubbers is examined. Methylphenyl silicone oils,
added to self-lubricating liquid silicone rubbers distribute
homogeneously in rubber and are incompatible with
silicone rubber. This incompatibility is the result of the
differences in the chemical potential between the two
phases of the system. Factors affecting the diffusion or
bleeding of oil from the rubber are examined, with
reference to applications such as automotive weather
seals. 5 refs. (Translated from Gummi Fasern Kunststoffe,
No.10, 2000, p.709)
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.811250
Item 16Patent Number: US 6156241 A1 20001205
IOLS AND PRODUCTION METHODS FORSAMETran D Q; Lind R J
Allergan
Intraocular lenses (IOLs) are produced using a
combination of steps, which increase the pull strength
References and Abstracts
70 © Copyright 2001 Rapra Technology Limited
between the fixation member of the IOL and the optic of
the IOL without requiring sophisticated high frequency
corona discharge activation, plasma activation or other
exotic activation of the fixation member or primer coating
of the fixation member. The silicone polymeric optic
members can be formed, for example, moulded, without
recesses to accommodate the fixation members. Such
recesses can be formed and provided with a quantity of
silicone polymeric material precursor composition after
the optic members are produced. The fixation members
are then placed in the recesses and secured to the optic
members.
USA
Accession no.809891
Item 17Patent Number: EP 1079398 A2 20010228
SILICONE RUBBER COMPOSITIONS, THEIRPREPARATION AND USE IN HIGH-VOLTAGEELECTRICAL INSULATION CONTEXTSMeguriya N; Azechi S; Sekiguchi S
Shin-Etsu Chemical Co.Ltd.
Disclosed is a thixotropic silicone rubber composition
comprising (A) an organopolysiloxane having, on
average, at least two alkenyl groups in a molecule and a
degree of polymerisation of up to 1,200, (B) a liquid
organohydrogenpolysiloxane having at least two
hydrogen atoms each attached to a silicon atom, (C)
aluminium hydroxide, (D) an addition reaction catalyst,
(E) a thixotropic agent and, optionally, (F) a tackifier. It
cures at room or elevated temperature into a silicone
rubber having high strength and electrical insulating
properties sufficient to serve as a high-voltage electrical
insulator. The composition is so thixotropic that it may
be used to repair chipped portions of insulators.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.808483
Item 18Macromolecular Materials and Engineering
Vols.284-5, Dec.2000, p.76-80
RUBBER PROCESSING WITH GAS-ASSISTEDINJECTION MOULDING (R-GAIM)Haberstroh E; Wehr H
IKV
Gas-assisted injection moulding was used to produce
hollow parts made of rubber (EPDM) and liquid silicon
rubber (LSR). The technique could be applied more easily
to LSR moulding than to the processing of EPDM
compounds used in this study. The gas needle and gas
injection area needed to be adapted to the processing
characteristics of the rubber in injection moulding. Further
studies will include the determination of the basic
requirements for mould design, the refinement of the
process control, different gas-assisted injection moulding
variants, limitations of the process and necessary material
characteristics. 14 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.807879
Item 19Composites Science & Technology
61, No.3, 2001, p.453-8
STUDY OF THE FEASIBILITY OF AMONOBLOCK RACING MOTORCYCLE RIMLegrand M; Ngoc Q A P
ENSAM
Details are given of the use of silicone rubber tools for
manufacturing the monoblock of a racing motorcycle. The
tool is made by vulcanising and inflating uncured sheets
of silicone rubber inside a forming mould. During cooling
these tools are regulated under a controlled pressure in
order to obtain an optimal pressing. 5 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.807674
Item 20Journal of Applied Polymer Science
79, No.12, 21st March 2001, p.2251-7
CHARACTERISTICS OF SURFACEWETTABILITY AND HYDROPHOBICITY ANDRECOVERY ABILITY OF EPDM RUBBER ANDSILICONE RUBBER FOR POLYMERINSULATORSJin Kuk Kim; In-Hwan Kim
Gyeongsang,National University
Test slabs of EPDM and silicone rubber were assessed
for long-term pollution resistance by subjecting the slabs
to a surface corona ageing treatment. The results obtained
showed good hydrophobicity of these materials and their
transfer of the contaminant layer deposited on the shed
surface of the insulator. The EPDM and silicone rubbers
are polymers of low density and they maintain significant
resistance to attack by oxygen and ozone. This study
measured the contact angle between water droplets and
other materials to determine the hydrophobicity and
recovery ability of these synthetic polymers. Surface
morphology was also studied in order to obtain a visual
confirmation of the migration phenomena. 15 refs.
SOUTH KOREA
Accession no.807404
Item 21Revista de Plasticos Modernos
79, No.527, May 2000, p.582-8
Spanish
NEW GAS PERMEABLE HYDROGELS FORPROLONGED USE CONTACT LENSES
References and Abstracts
© Copyright 2001Rapra Technology Limited 71
Lasagabaster A; Moreno F; Rodriguez M A; de la
Orden M U
Madrid,Universidad Complutense
Problems of corneal damage caused by the prolonged
wear of contact lenses are discussed, and developments
in highly oxygen permeable polymeric hydrogels aimed
at overcoming such problems are examined.
Consideration is given to the oxygen permeability,
mechanical properties, wettability and resistance to lipid
deposition of hydrogels based on a number of polymers,
with particular reference to silicone polymers
commercially used in the manufacture of contact lenses.
15 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN;
WESTERN EUROPE
Accession no.807118
Item 22Analytical Chemistry
73, No.1, 1st Jan.2001, p.8-12
MICROMOSAIC IMMUNOASSAYSBernard A; Michel B; Delamarche E
IBM Research Division
Miniaturised mosaic immunoassays were developed
based on patterning lines of antigens onto a surface
(polydimethylsiloxane) by means of a microfluidic
network. Solutions to be analysed were delivered by the
channels of a second microfluidic network across thepattern of antigens. Specific binding of the target
antibodies with their immobilised antigens on the surface
resulted in a mosaic of binding events that could readily
be visualised in one screening using fluorescence. It was
thus possible to screen solutions for antibodies in a
combinatorial manner with great economy of reagents and
at a high degree of miniaturisation. Such mosaic-format
immunoassays were compatible with the sensitivity and
reliability required for immunodiagnostic methods. 27
refs.
SWITZERLAND; WESTERN EUROPE
Accession no.805159
Item 23Journal of Biomedical Materials Research
55, No.1, April 2001, p.33-9
IN VITRO BIOCOMPATIBILITY ASSESSMENTOF NATURALLY DERIVED AND SYNTHETICBIOMATERIALS USING NORMAL HUMANUROTHELIAL CELLSPariente J-L; Kim B-S; Atala A
Boston,Harvard Medical School
A primary normal human urothelial cell culture was used
to evaluate the in vitro biocompatibility of natural and
polymeric biomaterials. The cell viability, metabolic
activity, apoptotic properties and DNA-synthesis activity
were measured to determine cytotoxicity and bioactive
effects. Data are presented for polylactic acid,
polyglycolic acid, lactic acid-glycolic acid copolymers
and silicone polymers. 39 refs.
USA
Accession no.804585
Item 24Journal of Materials Science. Materials in Medicine
12, No.1, Jan.2001, p.15-21
DESIGN OF A SIMULATED URETHRA MODELFOR THE QUANTITATIVE ASSESSMENT OFURINARY CATHETER LUBRICITYJones D S; Garvin C P; Gorman S P
Belfast,Queen’s University
Details are given of the development of an in vitro urethral
model to characterise and compare the insertion and
removal properties of commercially available intermittent
catheters. The tensile properties of the silicone catheters
was also evaluated. 16 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.804576
Item 25Plastiques & Elastomeres Magazine
52, No.6, Aug./Sept.2000, p.14/7
French
TEXTILE COATINGDesne F
Rhodia Silicones
The use of silicone rubbers in the coating of fabrics for
clothing and automotive air bags is discussed, and
reference is made to developments by Rhodia Silicones
in Rhodorsil and Silbione silicone rubbers for use in such
applications.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.803934
Item 26Plastiques & Elastomeres Magazine
52, No.6, Aug./Sept.2000, p.8-11
French
SURVEY OF SILICONE ELASTOMERSGouin F
Consideration is given to the vulcanisation, processing,
properties and applications of silicone rubbers, and
reference is made to some developments by Dow Corning,
Rhodia and Wacker in silicone rubbers and platinum
curing agents.
RHODIA SILICONES; WACKER SILICONES;
GESSIL; DOW CORNING CORP.EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
GERMANY; USA; WESTERN EUROPE
Accession no.803932
References and Abstracts
72 © Copyright 2001 Rapra Technology Limited
Item 27Adhasion Kleben & Dichten
42, No.4, 1998, p.40
German
SEALING DEVICES FOR PLUG-INCONNECTIONS
Under the brand name GelTek the firm Raychem from
Ottobrunn has brought out seals that are suitable for
sealing plug-in connections in motor vehicles, especially
for the new generation of miniaturised, high-pole plug-in
connections with a narrow contact gap. These seals are
based on a molecularly cross-linked silicon gel jointing
compound. This article also looks at wire contacts and
production of cable trees. Additional sealants are not
required. With slight pressure the gel seals joints
immediately making them watertight.
RAYCHEMEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.803787
Item 28Journal of Applied Medical Polymers
4, No.2, Autumn 2000, p.81-7
MECHANICAL CHARACTERISATION OFSILICONE ELASTOMER FOR USE IN AMEDICAL DEVICESarnowski E
Sulzer Carbomedics Inc.
A report is presented on the development of a set of
constitutive models to account for softening in silicone
rubbers for heart valve prostheses. These models were
distributed throughout a finite element mesh and used in
the design of a heart valve. A comparison was made of
the maximum predicted stress with data obtained from in
load-controlled fatigue testing in order to predict the
service life of the designs and a fatigue specimen
designed, analysed and tested to provide fatigue-lifetime
data. 10 refs.
USA
Accession no.803436
Item 29Antec 2000.Conference proceedings.
Orlando, Fl., 7th-11th May, 2000, paper 534
CATHETER DESIGNED TO GIVE IMMEDIATE,PAINLESS, OUT-PATIENT RELIEF TO BPHSUFFERERSCzuba L
Herbst LaZar Bell Inc.
(SPE)
The development of a silicone rubber catheter for the
treatment of benign prostatic hyperplasia is described. The
catheter is used to introduce a microwave antenna into
the affected area, and consists of multi-walled tubing to
provide cooling, and has a compression balloon with a
fixed outside diameter to create a biological stent in the
affected area. 3 refs.
USA
Accession no.803381
Item 30Antec 2000.Conference proceedings.
Orlando, Fl., 7th-11th May, 2000, paper 532
POLYURETHANE AND SILICONE AS NON-ALLERGENIC ALTERNATIVES TO LATEX FORMEDICAL BALLOONSShah T M
Polyzen Inc.
(SPE)
Polyurethanes and polysilicones have been developed for
medical applications which match the mechanical and
physical properties of natural latex, and are not allergenic.
They also have enhanced chemical resistance and reduced
UV sensitivity. Products may be shaped by dip moulding,
using a heated mandrel, the polymers being dissolved in
suitable solvents. These polymers are particularly suitable
for the production of low pressure medical balloons.
Accession no.803379
Item 31Journal of Biomedical Materials Research (Applied
Biomaterials)
53, No.6, 2000, p.646-50
TEXTURED POLYDIMETHYLSILOXANEELASTOMERS IN THE HUMAN LARYNX:SAFETY AND EFFICIENCY OF USESittel C; Thumfart W F; Pototschnig C; Wittekindt C;
Eckel H E
Koln,Universitat; Innsbruck,Universitat
The systematic application and long-term results of
vulcanised polydimethylsiloxane (PDMS) particles in the
treatment of glottic insufficiency in the human larynx is
reported. Of ten patients treated with PDMS in the early
1990s, seven patients can be retrieved for reevaluation.
Laryngeal function is assessed by videostroboscopy,
expert rating and further characterised by the objective
parameters of voice profile and maximum phonation time.
All patients are asked for their personal impression of
the results. Mean follow-up time is 88.4 months. Glottic
closure is complete in five of seven patients. There are
no signs of granuloma formation or other pathologic
changes of the injected vocal folds. In four cases, voices
are rated normal or near-normal; two voices rated as fair;
one usable. All the patients report significant and lasting
voice improvement. None of the patients report any
problems related to PDMS. PDMS particles provide
permanent augmentation of human vocal fold volume
without complications. Their use is a valuable and safe
alternative when a definitive one-step procedure seems
advantageous. However, further studies are needed to
References and Abstracts
© Copyright 2001Rapra Technology Limited 73
assess voice improvement in comparison to other
materials. 34 refs.
AUSTRIA; EUROPEAN COMMUNITY; EUROPEAN UNION;
GERMANY; WESTERN EUROPE
Accession no.802623
Item 32Iranian Polymer Journal
9, No.3, July 2000, p.163-7
APPLICATION OF POLYDIMETHYLSILOXANEAS ADSORBENT FOR DETECTION OFALIPHATIC HYDROCARBON COMPOUNDSVAPOURS USING QUARTZ CRYSTALMICROBALANCE (QCM)Mirmohseni A; Hassanzadeh V
Tabriz,University
Polydimethylsiloxane (PDMS) is used as adsorbent for
detection and determination of some aliphatic hydro-
carbons such as n-pentane, n-hexane, n-heptane and
cyclohexane. The contamination of environment by
these volatile organic compounds is a serious problem
due to their potential human toxicity. Therefore, analysis
of these compounds has become more and more
important and various techniques have been developed
to target this aim. A thin layer of PDMS is coated at the
surface of an AT-cut gold-coated quartz crystal electrodes
and a sensor based on the technique of quartz crystal
microbalance is developed for the detection of these
organic vapours. Detection is based on the measurement
of the frequency shifts due to the adsorption of the
organic compounds on the polymer film. Calibration
graphs are constructed by plotting the frequency changes
(delta F/Hz) against the concentration of organic
compounds. Using this method, the detection of these
organic vapours is successfully carried out at parts per
million concentrations. 22 refs.
IRAN
Accession no.802521
Item 33Patent Number: US 6011105 A 20000104
FLAME RETARDANT SILICON RUBBERCOMPOSITION FOR COATING ELECTRICALWIRE AND CABLEOta K; Hirai K
Dow Corning Toray Silicone Co.Ltd.
The above composition comprises: (a) polyorgano-
siloxane with a given average compositional formula, (b)
microparticulate silica having a mean primary particle
diameter of at least 18 nm and a specific surface area no
greater than 95 sq.m./g, (c) platinum or a platinum
compound, (d) triazole compound, and (e) methyl-
substituted benzoyl peroxide.
JAPAN
Accession no.800949
Item 34Patent Number: US 6111221 A1 20000829
HEAT FIXING ROLLSMiyakoshi M; Shudo S; Tomizawa N; Kondou T
Shin-Etsu Chemical Co.Ltd.
These include a silicone rubber layer on a cylindrical metal
mandrel having a penetration of at least 10, according to
ASTM D1403, and a fluoropolymer layer thereon. The
silicone rubber layer is obtained by moulding and curing
an addition reaction type liquid silicone rubber
composition to the mandrel. The roller provides a
sufficient nip width under low pressure, improved
abrasion resistance, long-lasting toner release, and a
satisfactory fixing function even at a high speed over a
long period of time.
JAPAN; USA
Accession no.800308
Item 35European Rubber Journal
183, No.1, Jan.2001, p.18-9
JAMAK TAKES ON TRICO IN WIPER-BLADECONTESTBegin S
Premium-priced wiper blades produced by Jamak
Fabrication and Trico Products will go head-to-head in
the US automotive aftermarket. Jamak is touting its single-edge silicone blade it began producing in January for
Texaco. The company claims the Havoline blades last two
to three times as long as traditional, organic rubber blades
thanks to their resistance to ozone, UV rays and extreme
heat and cold. Trico insists its Teflon Blade gives superior
wiper performance. Trico’s blade has a beige strip on the
wiping edge to indicate the presence of Teflon that is
coextruded with NR.
JAMAK FABRICATION INC.; TRICO PRODUCTS
CORP.USA
Accession no.799078
Item 36Polymers for Advanced Technologies
11, Nos.8-12, Aug./Dec.2000, p.460-7
POLYSILANE LIGHT-EMITTING DIODESSuzuki H; Hoshino S; Furukawa K; Ebata K; Chien-
Hua Yuan; Bleyl I
NTT Basic Research Laboratories
The development of polysilane light-emitting diodes
(LEDs) made from a diaryl polysilane, poly(bis(p-n-
butylphenyl)silane)(PBPS), is described and comparison
is made with LEDs prepared using a conventional
polysilane, polymethylphenylsilane. In contrast to LEDs
based on conventional polysilanes in which a weak UV
electroluminescence(EL) was detected either with a strong
broad visible EL or only at low temps., room temp. pure
References and Abstracts
74 © Copyright 2001 Rapra Technology Limited
near-UV EL was observed with a quantum efficiency of
0.1% photons/electron with an electron injecting Al
electrode in PBPS-LEDs. The spectroscopic, electronic
and structural properties of PBPS were examined and the
improvements observed in the EL characteristics were
ascribed to them. The possible future direction of
polysilane LED research is considered and other potential
optoelectronic applications of polysilanes to the active
medium of lasers are mentioned. 33 refs. (5th International
Symposium on Polymers for Advanced Technologies,
Tokyo, Aug./Sept.1999)
JAPAN
Accession no.798024
Item 37Patent Number: US 6103819 A1 20000815
ADDITIVE FOR THE PREVENTION OFNITROSAMINE FORMATION IN SILICONEARTICLESLewis L N; Jeram E M
General Electric Co.
The present invention relates to a method for making
nitrosamine-free silicone articles by treating the mixture
of vinyl containing organopolysiloxane and filler with
hindered phenols, a nitrosamine-free composition and a
nitrosamine-free article made therefrom. A preferred
nitrosamine-free moulded article is a baby bottle nipple.
USA
Accession no.797938
Item 38Patent Number: US 6103804 A1 20000815
PROCESS FOR THE SEALING COMPONENTSEXPOSED TO AGGRESSIVE FUNCTIONALFLUIDS AND RTV SILICONE COMPOSITIONSSUITABLE FOR USE THEREINDavis T D
Wacker Silicones Corp.
RTV-1 silicone sealants resistant to deterioration in the
presence of aggressive functional fluids are prepared from
an organopolysiloxane component comprising a major
amount of silanol-functional organopolysiloxane, a
primary or secondary amine-functional crosslinker, and
both iron oxide and magnesium oxide, optionally together
with auxiliary fillers, adhesion promoters, catalysts, and
customary additives. The gasket materials are particularly
useful in axle and transaxle seals exposed to fuel
efficiency-promoting aggressive lubricants.
USA
Accession no.797924
Item 39Polymer Preprints. Volume 40. Number 2. August
1999. Conference proceedings.
New Orleans, La., August 1999, p.799-800
SYNTHESIS OF NITRIC OXIDE RELEASINGSILICONE RUBBERS FOR BIOMEDICALAPPLICATIONSZhang H; Schoenfisch M H; Meyerhoff M E
Michigan,University
(ACS,Div.of Polymer Chemistry)
Two approaches for preparing nitric oxide (NO) releasing
silicone rubber films are reported. Silicone rubber (SR)
is widely used in industry, consumer and medical products
for which NO release may prove useful. It is shown that
diazeniumdiolates can be anchored onto either a
polysiloxane matrix or fumed silica filler to fabricate NO
releasing silicone rubbers. 14 refs.
USA
Accession no.797268
Item 40Chemical Marketing Reporter
258, No.24, 11th Dec.2000, p.FR24
SILICONE PRODUCERS ROLL OUTINVESTMENTSBoswell C
There are eight major producers of silicones, with Dow
Corning the largest with a 36% share of the global market,
by value, in 1998. Between 1995 and 1998, the global
market for silicones and silanes grew at an average annual
rate of 6% from 5.7bn to 6.7bn US dollars. The greatestgrowth will be in Asia, where global producers are making
major investments in preparation. The most recent is a
joint venture announced by GE Silicones and Shin-Etsu
in October which will build a facility for the production
of silane monomers and siloxane intermediates at a site
in Southeast Asia. The US market for silicones and silanes
is valued at 2.065bn US dollars based on 1998 estimates.
WORLD
Accession no.797180
Item 41Patent Number: US 6106954 A1 20000822
SILICONE RUBBER COMPOSITIONS FORHIGH-VOLTAGE ELECTRICAL INSULATORSAND POLYMERIC BUSHINGSMeguriya N; Azechi S; Sekiguchi S; Yoshida T
Shin-Etsu Chemical Co.Ltd.
A silicone rubber composition is obtained by blending
(A) 100 parts by weight of an organopolysiloxane
composition of the addition reaction curing type with (B)
about 30 to 400 parts by weight of aluminium hydroxide,
which has been surface treated with an organosilane or
organosilazane substantially free of an aliphatic
unsaturated group or a partial hydrolysate thereof so that
the aluminium hydroxide has 0.01 to 2% by weight of
carbon affixed thereto. The composition maintains
silicone rubber properties even though it is loaded with
large amounts of aluminium hydroxide. It cures into a
References and Abstracts
© Copyright 2001Rapra Technology Limited 75
silicone rubber having improved high-voltage electrical
insulating properties and thus is suited for use as high-
voltage electrical insulators.
JAPAN; USA
Accession no.796589
Item 42Silicones in Coatings II. Conference proceedings.
Florida, USA, 24th-26th March 1998, paper 35
NEW GENERATION OF SILICONEELASTOMERS FOR AIRBAG COATINGSBohin F; Pouchelon A; Surprenant R
Rhodia Silicones
(Paint Research Association)
When airbag technology appeared on an industrial scale
in the middle of the 1980s, the first bags were neoprene
coated. Although neoprene met initially the performance
requirements of airbags, its efficiency was questionable
in the long term. By the end of the 1980s a new trend
appeared: silicone-coated fabrics. In the early 1990s,
specific liquid silicone rubber (RTV-2) was developed
for airbag applications. Being self-bonding onto the fibre,
they require the use of solvent during the coating process.
In 1996, a new generation of silicone elastomers for
coating was launched onto the European market.
Specifically designed to meet the airbag market evolution,
these new products provide specific rheological properties
allowing very thin coating without any change of the
technology or any use of a solvent. This of course allows
significant cost reductions for the customer. Offering
improved thermal protection to the fabric, they are very
well adapted to the new generation of airbag inflators
arising from the market. Their specific properties also
provides a 100% increase of the fabric tear strength. 6
refs.
USA
Accession no.795798
Item 43Silicones in Coatings II. Conference proceedings.
Florida, USA, 24th-26th March 1998, paper 31
BIOPROTECTING ORGANOSILICONECOATINGSVoronkov M; Chernov N
Irkutsk,Institute; Russian Academy of Sciences
(Paint Research Association)
To protect materials and parts against contamination
various polymer coatings are used, containing fungicides,
bactericides or other agents. Protective coatings are
known, based on organosilicone polymers modified with
heteroorganic compounds with antimicrobial activity,
particularly organotin compounds of the R3SnX type.
Heteroorganic fungicides may also be introduced into
hydrolysates of Si(OC2H5)4 or Ti(OC2H5)4, which are
used for clarification of optical glasses. Despite resistance
to bioovergrowth, physicochemical, mechanical and
protective properties of coatings containing heteroorganic
and inorganic fungicides degrade during operation. With
time they completely lose their fungicidal activity under
the action of adverse climatic factors or more or less
corrosive environment. This refers also to a great majority
of the known fungicidal and bactericidal coatings on
organic binders. Biocidal coatings based on polydiorgano-
siloxanes with terminal triorganostannyloxy groups were
patented. However these coatings are short-lived; they
are not chemically bound to the surface, and the OSnR3
terminal fragments are hydrolytically unstable. Extensive
and systematic studies are performed on carbofunctional
organosilicone monomers and resultant coatings. 73 refs.
RUSSIA
Accession no.795794
Item 44Silicones in Coatings II. Conference proceedings.
Florida, USA, 24th-26th March 1998, paper 17
MATRIX ASSISTED PULSED LASEREVAPORATION (MAPLE): APPLICATIONSWITH FUNCTIONALISED POLYSILOXANEMATERIALSMcGill R A; Chrisey D B; Mlsna T E; Pique A
US,Naval Research Laboratory
(Paint Research Association)
A novel polymer processing technique, matrix-assisted
pulsed laser evaporation (MAPLE), for the deposition of
polysiloxane and other materials, as ultra-thin and uniform
coatings has been developed. The technique involves
directing a pulsed excimer laser beam onto a frozen matrix
target composed of the polymer material in a solvent. The
process gently lifts polymeric material into the gas phase
with no apparent decomposition. A plume of material is
developed normal to the target, and a substrate positioned
incident to this plume is coated with the polymer. The
MAPLE technique offers a number of features that are
difficult to achieve with other polymer coating techniques,
including nanometer to micron thickness range, sub
monolayer thickness precision, high uniformity,
applicability to photosensitive materials and patterning
of surfaces. Highly functionalised polysiloxanes are
synthesised and deposited on a range of substrates by the
MAPLE technique, and characterised by IR spectroscopy
and optical microscopy. High quality, uniform and
adherent polysiloxane coatings are produced by the
optimised MAPLE technique. The physicochemical
properties of the coating are unaffected by the process,
and precise thickness control of the coating is straight-
forward. 26 refs.
USA
Accession no.795781
Item 45Patent Number: EP 1043363 A2 20001011
MOTHER MOLD-FORMING SILICONE
References and Abstracts
76 © Copyright 2001 Rapra Technology Limited
RUBBER COMPOSITION AND MOTHER MOLDOBTAINABLE THEREFROMMiyoshi K; Tanaka K
Shin-Etsu Chemical Co.Ltd.
In a silicone rubber composition comprising an
organopolysiloxane as a base polymer, 0.1 to 50 parts by
weight of a modified silicone fluid having a melting point
of up to 100C and a refractive index difference of 0.01 to
0.05 from the base polymer is blended per 100 parts by
weight of the composition. The composition is cast and
cured to form a mother mould, which maintains parting
properties over a long term.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.795412
Item 46158th. ACS Rubber Division Meeting - Fall 2000.
Conference preprints.
Cincinnati, Oh., 17th.-19th. Oct. 2000, paper 116
PEROXIDE CROSSLINKING OF SILICONECOMPOUNDSNiijhof L B G M; Cubera M
Akzo Nobel Polymer Chemicals BV; Akzo Nobel
polymer Chemicals LLS
(ACS,Rubber Div.)
A review is presented of the crosslinking of silicone
compounds by organic peroxides, with particularemphasis on the different peroxide classes available and
their cure characteristics in various silicone formulations.
Processing guidelines are included and the influence of
certain compounding ingredients is addressed. A
comparison is also made between platinum catalysed cure
systems and peroxide cure systems. 9 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; USA; WESTERN EUROPE
Accession no.794212
Item 47Antec 2000.Conference proceedings.
Orlando, Fl., 7th-11th May, 2000, paper 90
SIMULATION OF THE FILLING AND CURINGPHASE IN INJECTION MOLDING OF LIQUIDSILICONE RUBBER (LSR)Haberstroh E; Michaeli W; Henze E
Aachen,Institut fur Kunststoffverarbeitung; GE Bayer
Silicones GmbH & Co.KG
(SPE)
A model was developed for the filling and curing phases
in the injection moulding of two-part liquid silicone
rubbers, from considerations of the specific volume, the
cavity pressure and the material temperature. The filling
phase was modelled using 2-1/2-D simulation software
based on finite element methods, in which over 90% of
the cavity was filled under volume flow controlled
conditions and the balance by the thermal expansion of
the material. Curing, which is thickness-dependent, is
assumed to be complete when an average degree of curing
of 95% over the wall thickness is achieved, with a
minimum degree of 75%. 10 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.793821
Item 48High Performance Elastomers 2000. Conference
proceedings.
Berlin, Germany, 10th-11th Oct.2000, paper 13
ELASTOMERIC SILICONE ADHESIVES FORAUTOMOTIVE ENGINE GASKETS ANDSEALINGLoubet O
Rhodia Silicones
(Rapra Technology Ltd.; European Rubber Journal)
With an average growth of more than 10% each year,
silicone elastomers are used more and more in the
automotive industry, especially for gasketing applications
requiring thermal and chemical resistance. Today, Rhodia
Silicones with a wide range of gasketing technologies,
i.e. silk-screened gasket, injected gasket, formed-in-place-
gasket (FIPG) and cured-in-place-gasket (CIPG), has
reached a leading position in the automotive sealing
industry. The high level of performance of silicone
elastomers is achieved with an additional ease of
processability of the liquid silicone, thus making it the
economical solution for bonding and sealing automotive
parts. Building on the company’s experience of over 30
years in automotive gasketing, the company achieves the
innovation needs of customers through heat curing
elastomers (HCR), RTV1 and RTV2 technologies. A new
generation of elastomeric silicone adhesives targeted for
plastic parts has been developed. 21 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.792375
Item 49High Performance Elastomers 2000. Conference
proceedings.
Berlin, Germany, 10th-11th Oct.2000, paper 12
LIQUID SILICONE RUBBER. THE UNIQUEHIGH PERFORMANCE MATERIAL INAPPLICATIONS AND PROCESSINGTrumm C
Dow Corning GmbH
(Rapra Technology Ltd.; European Rubber Journal)
Injection moulding of liquid silicone rubbers is becoming
increasingly important. One reason for this is the increased
performance requirements of the finished articles. In
addition, more and more producers of rubber parts are
seeing benefits in the high level of automation and
References and Abstracts
© Copyright 2001Rapra Technology Limited 77
productivity. Silastic liquid silicone rubber was pioneered
by Dow Corning and introduced to the rubber fabrication
marketplace in the late 1970s. Today the processing and
product advantages of LSR are exploited in many existing
and new applications. A broad product line is available
both for general applications and certain LSRs tailored
for specific requirements. LSRs are liquids with
viscosities that vary from easily pourable to pastes. These
two component materials are mostly used in a 1:1 ratio
and consist of polysiloxane polymers or copolymers that
are vulcanised above 120 deg.C by polyaddition. Aspects
covered include technology advantages, application
examples, LSR rheology, injection moulding of LSR, and
properties and mould design.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.792374
Item 50International Polymer Science and Technology
27, No.9, 2000, p.T/24-5
HEAT RESISTANCE OF SILICONE RUBBERFILLED WITH HEAT-EXPANDED GRAPHITEDedov A V; Nazarov V G
Tekhindustriya-M Closed Joint Stock Co.
The influence is investigated of dispersed heat-expanded
graphite on the temperature dependences of the strength
of composites based on silicone rubber. It was established
that heating of the material increases the mobility of the
segments of the macromolecules and the relaxation rate,
which leads to a more uniform distribution of the
mechanical load and to an increase in the strength of the
composite. Treatment of the composite at 200 degrees C
for 2 hours was found to be the optimum, and the highest
strength with such treatment was found to be that of a
composite containing 20 wt.% heat-expanded graphite. 4
refs. Translation of Kauchuk i Rezina, No.2, 2000, p.8.
RUSSIA
Accession no.791813
Item 51Plastics, Rubber and Composites
29, No.5, 2000, p.229-34
EFFECT OF CAVITY PRESSURE ONCROSSLINK DENSITY OF INJECTIONMOULDED SILICONE RUBBERBarbaroux M; Regnier G; Verdu J
Dow Corning Healthcare Industries; Ecole Nationale
Superieure d’Arts et Metiers
The effects of injection moulding conditions
(temperatures 120 and 160 deg.C, pressures from 5 to 50
MPa) on the crosslink density of the resulting parts
(determined from equilibrium solvent swelling
experiments) are studied for an elastomer of the liquid
silicone rubber type, in which crosslinking results from
platinum catalysed vinyl-silane addition. It is shown,
unexpectedly, that a pressure increase leads to an increase
in the cure rate, despite the unfavourable effect of pressure
on viscosity. 22 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.789932
Item 52Patent Number: EP 1031596 A1 20000830
KEY PAD WITH RIGID RESIN KEY TOPNishi K
Polymatech Co.Ltd.
A key pad having a rigid key top is disclosed, which is
not subject to key top detachment or dislocation and does
not require key detachment prevention means, such as a
collar. The key top is adhered to a silicone rubber key
pad with a silicone base adhesive by providing a urethane
base adhesion substrate layer on the back of the key top.
EUROPEAN COMMUNITY; EUROPEAN UNION; WESTERN
EUROPE-GENERAL
Accession no.787625
Item 53Patent Number: US 5830951 A 19981103
POLYVINYLSILOXANE IMPRESSIONMATERIALFiedler J H
Dentsply DeTrey GmbH
Improved two component polymerisable polyorgano-
siloxane compositions are described, particularly for use
in making dental impressions, having improved tear
strength and wettability. Improved tear strength results from
inclusion of a quadri-functional polysiloxane having a vinyl
content of 0.16 to 0.24 m-mole/g. Working time is
maintained by including sufficient amounts of a retarder
composition that delays onset of the vinyl polymerisation.
Wettability is improved by including a surfactant resulting
in a surface contact angle with water at three minutes of
less than 50 degrees. The surfactant chosen has an HLB of
8-11, such that the wetting contact angle is achieved within
less than two minutes and remains wetting throughout the
working time of the impression taking, substantially
improving impression quality. A low viscosity impression
material is provided and includes a base component and a
catalyst component. Both components are siloxane-based
materials.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.787417
Item 54IRC 2000. Conference proceedings.
Helsinki, Finland, 13th-15th June 2000, paper 79
SILICONE RUBBER: INNOVATIONS THATCOMPETE
References and Abstracts
78 © Copyright 2001 Rapra Technology Limited
Dietl S
Wacker Chemie GmbH
(Nordic Council of Rubber Technology)
The developments in silicone rubber described open up
possibilities of higher productivity and improved quality.
The concept of fast peroxide-free curing/no post cure and
self-bonding silicone rubber materials provide new and
versatile solutions to the silicone rubber and plastic
processors.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.787111
Item 55Patent Number: US 6051642 A1 20000418
SILICONE COMPOSITION WITH IMPROVEDHIGH TEMPERATURE TOLERANCETkaczyk J E; Klug F J; Amarasekera J; Sumpter C A
General Electric Co.
A high temperature insulating composite composition
comprising at least one ground silicate mineral and at least
one silicone polymer. The at least one ground silicate
mineral is at least one mineral selected from the group of
olivine group; garnet group; aluminosilicates; ring
silicates; chain silicates; and sheet silicates. The high
temperature insulating material has particular usefulness
for insulating electrical wires.
USA
Accession no.786716
Item 56Journal of Applied Polymer Science
78, No.4, 24th October, 2000, p.724-31
SILICON-BASED MATERIALS PREPARED BYIPN FORMATION AND THEIR PROPERTIESTsumura M; Iwahara T
Kaneka Corp.
Silicon-based interpenetrating networks (IPNs) were
prepared from a ladder silsesquioxane oligomer and a
polycarbosilane by hydrosilylation polymerisation of
bifunctional Si-H and Si-vinyl monomers. This was
followed by melt and compression moulding of the B-
staged resin. Materials of various shapes were formed
and the flexural modulus and Izod impact strength were
evaluated, and found to be larger than those for each
component. The thermal, electrical and optical properties
were also measured. 18 refs.
JAPAN
Accession no.786476
Item 57Iranian Journal of Polymer Science & Technology
13, No.1, Spring 2000, p.1-7
Persian
PRODUCTION OF A POLYMERIC OCULAR
PROSTHESIS FOR GLAUCOMA THERAPYJafary M R; Mirzadeh H; Eslami Y; Amini H
Amirkabir,University of Technology; Tehran University
of Medical Science
The manufacture of moulds by electroforming and
preparation of prostheses with both the plate and connecting
tube made from silicone rubber are described. The results
of in vitro tests performed to evaluate the biocompatibility
of the prostheses are also reported. 18 refs.
IRAN
Accession no.786386
Item 58Patent Number: US 6054518 A1 20000425
SILICONE RUBBER MOLDINGCOMPOSITIONS AND METHOD FORPRODUCING SILICONE RUBBER MOLDEDPARTSHayashida O
Shin-Etsu Chemical Co.Ltd.
In a silicone rubber composition comprising an
organopolysiloxane, reinforcing silica, and a curing agent,
an ester wax, typically having a melting point of 40 to
150C is blended as an abherent. When the composition is
moulded in a mould, the flow of the composition in the
mould and the parting of the cured silicone rubber from
the mould are significantly improved.
JAPAN; USA
Accession no.786311
Item 59Patent Number: US 6069186 A1 20000530
RADIATION-CURABLE SILICONE RUBBERCOMPOSITIONOkinoshima H; Kashiwagi T; Yamaguchi S
Shin-Etsu Chemical Co.Ltd.
A radiation-curable silicone rubber composition is provided
which includes: (A) a specific organopolysiloxane having
radiation-sensitive (meth)acryloyl groups at the both
terminals of the molecular chain, (B) a photosensitiser; (C)
a tetraalkoxysilane or a partial hydrolysis-condensation
product thereof; and (D) optionally together with a specific
organic titanium compound. This composition is curable
upon irradiation by ultraviolet rays for a short time and
exhibits adhesion quickly. Hence, it is useful for the
bonding, coating and potting of various substrates. This
composition also has a relatively weak adhesion
immediately after curing, and can be peeled from the
substrate with ease for a while. Hence, it is also suited for
uses where repair is required. Because of a high curing
rate, it can be effective for, e.g. making a process short,
improving productivity and saving energy in the
manufacture of electric and electronic parts.
JAPAN; USA
Accession no.786163
References and Abstracts
© Copyright 2001Rapra Technology Limited 79
Item 60European Rubber Journal
182, No.9, Sept.2000, p.28/31
SILICONE GRADES FOR CO-MOULDINGShaw D
Wacker-Chemie has developed a new grade of liquid
silicone elastomer, Elastosil LR. The benefit of this
material is that it offers easy mould release after a short
period of elevated temperatures, such as the cure cycle,
but then goes on to develop good bond strengths over a
period of 24 hours or so. This makes it ideal for
overmoulding processes or where a thin layer of silicone
needs to be applied over another substrate. The material
bonds to thermoplastics, although not all. Applications
include water-resistant mobile phones, shower heads and
electrical connectors. The company is introducing a high
temperature vulcanisation grade of the self-adhesive
silicone later this year which has been developed for
adhesion to metals. One potential application is for
exhaust pipe mounts used in cars.
WACKER-CHEMIE GMBHEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.785116
Item 61Journal of Biomedical Materials Research
51, No.3, 5th Sept. 2000, p.408-12
IN VITRO FORMATION OF OROPHARYNGEALBIOFILMS ON SILICONE RUBBER TREATEDWITH A PALLADIUM/TIN SALT MIXTUREDijk F; Westerhof M; Busscher H J; van Luyn M J A;
van der Mei H C
Groningen,University
Silicone rubber voice prostheses were treated with a
colloidal palladium/tin solution to form a thin metal coat
intended to discourage biofilm formation. The effect of
the coating on airflow resistance and cytotoxicity was
examined. 28 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.782970
Item 62Patent Number: US 6042766 A1 20000328
METHOD OF FORMING ARTIFICIAL ROCKSHEATHINGBahr G J
Apparatus and method for the fabrication of semi-flexible
artificial rock sheathing are disclosed. A one-coat silicone
elastomer is brushed or sprayed on the surface of a
substantially flat natural rock formation to form a mould
that is adhered to a wood-framed fibreglass cradle that
holds the shape of the mould. When removed from the
rock formation, the mould is sprayed with a thermoplastic
elastomer to form a semi-flexible rock sheathing having
the same characteristics as the natural rock surface from
which the mould was formed. After the materials are fully
cured, the sheathing sheet may be separated from the
mould and used for the fabrication of rock or rock
structures by attaching sheathing sheets to the exterior of
a framework, followed by cutting and forming different
shapes.
USA
Accession no.782380
Item 63Patent Number: US 6037279 A1 20000314
COATED TEXTILE FABRICSBrookman L; Lawson D W
Dow Corning Ltd.
Disclosed is a coated textile fabric, which is useful for
fabricating automobile airbags. A surface of the textile
fabric is coated with first and second layers of
polyorganosiloxane-based elastomeric material, the first
layer being disposed between the textile surface and the
second layer. The polyorganosiloxane-based material of
the first layer exhibits an elongation at break of at least
400%. The polyorganosiloxane-based material of the
second layer exhibits a tear strength of at least 30 kN/m.
USA
Accession no.780295
Item 64Rubber World
222, No.3, June 2000, p.36/48
MULTI-COMPONENT INJECTION-MOULDINGOF RIGID-FLEXIBLE COMBINATIONSRonnewinkel C; Haberstroh E
Institut fur Kunststoffverarbeitung
Multi-component injection moulding offers ecological
and economical advantages. Combinations of rigid and
flexible materials are of major interest to the industry.
Due to their properties, curing rubbers and liquid silicone
rubbers allow extended applications of rigid-flexible
combinations and can substitute rubber-metal parts. The
examinations show a good adhesion strength between
thermoplastics and LSR, and between polyamide 6,12 and
X-NBR rubber. In order to find suitable mould concepts
for these material combinations, it will be demonstrated
how to use computer simulation for the analysis of
temperature distribution and curing rate. 12 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.780117
Item 65Rubber World
222, No.3, June 2000, p.26/35
NEW TRENDS IN SILICONE ELASTOMERTECHNOLOGY
References and Abstracts
80 © Copyright 2001 Rapra Technology Limited
Burkus F S; Amarasekera J
General Electric Co.,Silicones Div.
Siloxanes offer unique properties as elastomers and
therefore are being used in increasing amounts for such
applications. Liquid injection moulded silicone materials
have excellent physical and chemical properties which
make them suitable alternatives to standard millable and
pourable siloxane elastomers. New advances in liquid
injection moulded siloxane materials, including self-
bonding, low compression set and controlled force
deflection, address some previous issues that have
limited the use of these systems in certain applications.
Advances in mould design have enabled a two-shot ETP/
liquid injection moulded elastomer system to be
developed. 6 refs.
USA
Accession no.780116
Item 66Rubber and Plastics News
29, No.22, 29th May 2000, p.22
MCGHAN MEDICAL GETS OK FOR SALINEIMPLANTSMoore M
McGhan Medical, a breast implant manufacturer, having
received government approval to keep saline-filled
implants on the market, will seek to get the near-ban on
silicone-gel implants lifted. A study on silicone implants
from the FDA shows that silicone implants often rupture
in women’s bodies without their knowing, but McGhan
says its implants are much stronger and better than the
devices studied in the report.
MCGHAN MEDICAL CORP.
USA
Accession no.780110
Item 67International Polymer Science and Technology
27, No.5, 2000, p.T/6-T/13. (Translation of Gummi
Fasern Kunststoffe, No. 3, 2000, p. 162)
PRODUCTION OF LARGE-DIMENSIONEDARTICLES FROM SILICONE ELASTOMERSKrell V
The production of large-dimensioned articles from high
temperature vulcanising silicone rubber and liquid silicone
rubbers is described, with respect to the processing
equipment, moulding tools, and processing techniques.
Examples are included of products produced by these
techniques, and include an outdoor terminal plug with
and without field control element, long rod insulators, a
lightening conductor, and an angled plug.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.779949
Item 68International Polymer Science and Technology
27, No.4, 2000, p.T/25-T/28. (Translation of Kauchuk i
Rezina, No.6, 1999, p.8)
PRODUCTS MADE FROM POLYSILOXANESWITH A PROPERTY GRADIENTBritove V P; Yurkhanov V B; Nikolaev O O; Bogdanov
V V
St.Petersburg,State Technical University
It is demonstrated that it is possible to produce products
with different properties on their working surfaces, by a
combination of thermal and radiation vulcanisation
methods. In particular, the crosslinking of polysiloxanes
for use in medical applications, is discussed. The results
of modification by these combined vulcanisation
techniques are examined with reference to
physicomechanical properties. 8 refs.
RUSSIA
Accession no.779702
Item 69Advanced Composites Letters
9, No.2, 2000, p.115-23
ANALYSIS OF EXPLANTED SILICONE/SILICACOMPOSITE BREAST IMPLANTSBrandon H J; Young V L; Jerina K L; Wolf C J
Washington,University
The effect of implantation time on the physical,
mechanical and chemical properties of silicone rubber
(Silastic II)/silica gel breast implants was investigated and
the results compared with those for lot-matched control
(unimplanted) samples. In vivo duration times ranged
from 4 months to 10 years. The tensile strengths of explant
and control samples were determined using identical
testing protocols as were the tensile strengths of implants
extracted with hexane to remove non-crosslinked
silicones. Average molec.wts. between crosslinks were
determined by swelling measurements. 5 refs.
USA
Accession no.778727
Item 70Applied Organometallic Chemistry
14, No.6, June 2000, p.287-303
ORGANOSILICON ION-EXCHANGE ANDCOMPLEXING ADSORBENTSVoronkov M G; Vlasova N N; Pozhidaev Y N
Russian Academy of Sciences
Literature data concerning research organosilicon ion-
exchangers and complexing agents are summarised and
systematised. Data on organophilic organosilicon
adsorbents and sorption systems for chromatography are
not considered. 136 refs.
RUSSIA
Accession no.778015
References and Abstracts
© Copyright 2001Rapra Technology Limited 81
Item 71Journal of Biomedical Materials Research (Applied
Biomaterials)
53, No.3, 2000, p.267-75
FABRICATION OF MICROTEXTUREDMEMBRANES FOR CARDIAC MYOCYTEATTACHMENT AND ORIENTATIONDeutsch J; Motlagh D; Russell B; Desai T A
Illinois,University
Details are given of the preparation of microtextured
silicone membranes using photolithography and
microfabrication techniques. The attachment of cardiac
myocytes onto these membranes was investigated. 34 refs.
USA
Accession no.777781
Item 72Patent Number: EP 1006165 A2 20000607
COATING MATERIALMorita Y; Furukawa H; Aso T
Dow Corning Toray Silicone Co.Ltd.
A highly weather-resistant coating, which exhibits
excellent water resistance and water repellency, contains
a vinyl-type polymer having a pendant carbosiloxane
dendrimer structure. The coating is used on construction
materials, buildings and structures undercoated with an
organic coating material, automobiles, railroad rollingstock, ships, aircraft, bridges, commercial and industrial
plants and electrical and electronic instruments and
devices.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.777717
Item 73Patent Number: EP 1006164 A2 20000607
SILICONE RUBBER BASE COMPOUND FORELECTRICAL WIRE COATING, SILICONECOMPOSITION FOR ELECTRICAL WIRECOATING, AND PROCESS FOR THEPRODUCTION OF SILICONE RUBBER COATEDELECTRICAL WIREBaba K; Ota K
Dow Corning Toray Silicone Co.Ltd.
Disclosed is a silicone rubber base compound for electrical
wire coating such that when it is extruded using an
extruding machine having a variable screw with an L/D=10
and a die with a diameter of 1 mm attached thereto at a
barrel and head temperature of 70C, the per-minute extruder
output rate at a screw rotation speed of 100 rpm is not less
than 1.2 times the extruder output rate at a screw rotation
speed of 50 rpm. It may be obtained by compounding diacyl
organic peroxide consisting of carbon atoms, hydrogen
atoms and oxygen atoms with the silicone rubber base
compound for electrical wire coating.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.777716
Item 74Patent Number: US 6030684 A1 20000229
PROTECTING ELECTRONIC COMPONENTS INACIDIC AND BASIC ENVIRONMENTPolak A J; Baker T L
Motorola Inc.
Electronic devices, which are protected by an organic
polymeric encapsulant and placed in a corrosive
environment, can have added protection by dispersing in
the encapsulant particles of a solid buffer which tend to
neutralise the effect of the corrosive agent. This approach
is quite effective when strong acids are the corrosive
agents and when solid acid-base buffers are dispersed in
the polymeric material. The encapsulant may be
elastomeric. Silicone elastomers containing solid acid-
base buffers are quite effective in protecting the
underlying electronic device from corrosion by strong
acids.
USA
Accession no.777524
Item 75Patent Number: US 5982041 A 19991109
SILICONE DIE ATTACH ADHESIVE, METHODFOR THE FABRICATION OFSEMICONDUCTOR DEVICES, ANDSEMICONDUCTOR DEVICESMitani O; Nakayoshi K; Tazawa R; Mine K
Dow Corning Toray Silicone Co.Ltd.
A silicone die attach adhesive is disclosed which
comprises a silicone composition which cures both
through the free radical reaction of acrylic-functional
organopolysiloxane as induced by exposure to high-
energy radiation and through the hydrosilylation reaction
between alkenyl-functional organopolysiloxane and
silicon-bonded hydrogen-functional organopolysiloxane.
Also disclosed is a fabrication method characterised by
mounting a semiconductor chip on a substrate or in a
package with the aforesaid silicone die attach adhesive
sandwiched between the semiconductor chip and substrate
or package, then inducing the free radical reaction of the
acrylic functional groups by exposing the die attach
adhesive to high energy radiation, and thereafter curing
the die attach adhesive by the hydrosilylation reaction. A
semiconductor device, characterised in that it has been
fabricated by the above-described method, is disclosed.
JAPAN
Accession no.774597
Item 76Patent Number: US 5973061 A 19991026
References and Abstracts
82 © Copyright 2001 Rapra Technology Limited
AQUEOUS SILICONE DISPERSIONSCROSSLINKABLE INTO ELASTOMERICSTATE BY DEHYDRATIONFeder M; Ulrich J
Rhone-Poulenc Chimie
The above dispersions comprise: (a) 100 pbw of an oil-
in-water emulsion of an alpha-omega-(dihydroxy)
polydiorganosiloxane stabilised with at least one anionic
or nonionic surface active agent, or mixture thereof, (b)
1-100 pbw of an hydroxylated silicone resin containing,
per molecule, at least two different recurring structural
units selected from a given group, the resin having a
hydroxyl group weight content of 0.1-10%, (c) 0-250 pbw
of a nonsiliceous inorganic filler, and (d) 0.01-3 pbw of a
metal curing catalyst compound. These dispersions have
a solids content of at least 40%.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.774410
Item 77European Rubber Journal
182, No.1, Jan.2000, p.21-4
TOUGH SERVICE CONDITIONS MEAN TOUGHELASTOMERSWhite L
Fluoroelastomer growth in the US of around 4%/year in
automotive uses is predicted in a recent market report.Dyneon’s base-resistant Fluorel BRE fluoroelastomers are
formulated to withstand the demanding conditions found
in basic and amine-containing environments, most notably
those involving new lubricating fluids in the automotive
industry. DuPont Dow Elastomers’ range, Viton Extreme
ETP, is described as suitable for severe sealing
applications requiring a combination of heat, fluids and
base resistance with low-temperature flexibility. Makers
of silicone elastomers and HNBR have grades which are
suitable for various fuel-contact applications.
USA
Accession no.772741
Item 78International Polymer Science and Technology
26, No.5, 1999, p.44-56
HEAT CURING SILICONE RUBBERSNagy J; Roth G
The article reviews the development of silicones from silane
monomers, polysiloxanes, silicone polymers and rubbers
to the chemistry of crosslinking and its economic
importance. Mechanical and electrical properties of a
number of Wacker Elastosil silicone rubbers are compared.
Applications of silicone rubbers are also listed. 14 refs.
Abs. translation from Muanyag es Gumi, No.2, 1999, p.45.
EASTERN EUROPE; HUNGARY
Accession no.771233
Item 79British Plastics and Rubber
April 2000, p.23-4
LIQUID SILICONE OFFERS THE PLASTICMOULDER A PERFORMANCE ELASTOMER
The injection moulding of liquid silicone rubber is
discussed, with particular reference to the use of specially
modified injection moulding machines. The
characteristics and properties of silicone rubbers are
described, and advantages of these properties in
applications in end use industries such as automotive,
electronic, medical, and household appliances. One area
of application driving the growth in their use is the
increase in multi-component moulding with which a
sealing element can be added to a rigid component in one
moulding operation. Machine design modifications are
examined.
WESTERN EUROPE
Accession no.771105
Item 80Biomaterials
21, No.7, 2000, p.649-65
BIOMATERIALS USED IN THE POSTERIORSEGMENT OF THE EYEColthurst M J; Williams R L; Hiscott P S; Grierson I
Liverpool,University
This review focuses on disorders affecting retinal
detachment, and briefly describes the eye anatomy and
the nature and treatment of posterior segment eye
disorders. The roles, required properties and suitability
of materials used in vitreoretinal surgery such as scleral
buckles, tamponade agents or drug delivery devices are
reviewed. Materials used in posterior segment eye surgery
range from non-degradable solid implants to water-soluble
fluids. Silicone oil is currently the most suitable vitreous
tamponade for long-term use but has many disadvantages.
Silicone in solid and non-biodegradable form has been
used for scleral buckles (explants attached to the outside
of the eye by sutures). Water-swellable hydrogel material
can be used for buckling procedures. Vitreous substitute
materials used in eye repair include semifluorinated
alkanes, silicone-fluorosilicone copolymer oil, methylated
collagen, hydroxypropylmethyl cellulose, and crosslinked
polyvinyl alcohol. 132 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.769343
Item 81Patent Number: EP 992560 A1 20000412
PROCESS FOR SEALING COMPONENTSEXPOSED TO AGGRESSIVE FUNCTIONALFLUIDS AND RTV SILICONE COMPOSITIONSSUITABLE FOR USE THEREINDavis T D
References and Abstracts
© Copyright 2001Rapra Technology Limited 83
Wacker-Chemie GmbH
RTV-1 silicone sealants resistant to deterioration in the
presence of aggressive functional fluids are prepared from
an organopolysiloxane component comprising a major
amount of silanol-functional organopolysiloxane, a
primary or secondary amine-functional crosslinker, and
both iron oxide and magnesium oxide, optionally together
with auxiliary fillers, adhesion promoters, catalysts, and
customary additives. The gasket materials are particularly
useful in axle and trans-axle seals exposed to fuel
efficiency-promoting aggressive lubricants.
EUROPEAN COMMUNITY; EUROPEAN UNION; USA;
WESTERN EUROPE-GENERAL
Accession no.769052
Item 82Patent Number: US 6004496 A 19991221
METHOD OF MAKING A SILICONE RUBBERWINDSHIELD WIPERReo N J
Specialty Silicone Products Inc.
High performance silicone rubber windshield wiper
blades are provided as a result of moulding a tintable
platinum group metal catalysed silicone compositions
having an intrinsic viscosity of less than 1.3. Improved
lubricity with respect to windshield wiper glass is
achieved by a moulding procedure which effects a transfer
such as a migration, or diffusion of release agent, forexample polytetrafluoroethylene, into the surface of the
silicone rubber windshield wiper blade.
USA
Accession no.768871
Item 83Injection Molding
8, No.4, April 2000, p.42/4
USING TECHNOLOGY TO STAY ON TIME ANDUNDER BUDGETManiscalco M
Boston Medical Products uses a combination of rapid
prototyping, rapid tooling and 3D CAD to bring low-
volume, injection moulded silicone rubber medical
devices to market on time and at a competitive price.
Rapid prototypes of the actual mould insert are produced
on a Sanders system. A toolmaker works with these
prototypes and returns sintered tool inserts within two
weeks.
BOSTON MEDICAL PRODUCTS INC.; CADKEY
INC.; NDM INC.USA
Accession no.768540
Item 84Patent Number: US 6001943 A 19991214
SILICONE GEL COMPOSITION AND SILICONEGEL FOR USE IN SEALING AND FILLING OFELECTRICAL AND ELECTRONIC PARTSEnami H; Hamada Y; Nakamura A; Saiki T
Dow Corning Toray Silicone Co.Ltd.
The present invention provides a silicone gel composition
for use in sealing and filling of electrical and electronic
parts, which are characterised by the fact that when the
composition is cured, the composition forms a silicone
gel in which the loss elastic modulus at a temperature of
25 deg C, and a shear frequency of 0.1 Hz is 100 to 1000
Pa, and in which the complex elastic modulus is 100000
Pa or less, and a silicone gel which is characterised by
the fact that in a silicone gel which seals or fills electrical
or electronic parts, the loss elastic modulus of this silicone
gel at 25 deg C and a shear frequency of 0.1 Hz is 100 to
10000 Pa, and the complex elastic modulus is 100000 Pa
or less.
JAPAN
Accession no.766438
Item 85Patent Number: EP 982345 A1 20000301
CONTINUOUS PROCESS FOR PRODUCING ASILICONE POLYMERCurrie J; Griffith P; Herron W; Taylor R
Dow Corning Corp.
This involves the sequential steps of (i) polymerisation
of a linear silanol group containing siloxane by
condensation polymerisation or of a cyclosiloxane by ring
opening polymerisation or of a mixture of the linear and
cyclosiloxanes with a phosphazene base in the presence
of water and the presence or absence of a filler in an
extruder, (ii) neutralising the reaction mixture in an
extruder and (iii) stripping the neutralised reaction mixture
to remove volatile materials. Preferably, step (iii) is
performed in an extruder. More preferably, steps (i), (ii)
and (iii) are all performed in the same extruder.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE; WESTERN EUROPE-GENERAL
Accession no.766190
Item 86New Scientist
165, No.2223, 29th Jan.1999, p.36-9
BORDER OF ORDERBrooks M
The secret of the winter flounder’s survival is a tiny
antifreeze protein: as the disordered water molecules in
its blood begin to turn into the ordered structure of ice,
the protein moves in to break them apart. Just as the
flounder can hold molecular order at bay in its
bloodstream, researchers are learning to map and control
the boundaries between ordered and disordered materials.
Eventually, they hope this will help them devise better
References and Abstracts
84 © Copyright 2001 Rapra Technology Limited
ways to preserve frozen foods or design materials with
remarkable properties to order. But first the researchers
aim to marry the processing power of silicon with the
flexibility of plastics to create cheap, bendy and disposable
electronics. If researchers can make the marriage work,
it could lead to drug packaging that sports unbreakable
polymer display screens, for example. Touch the screen
and health information or medical advice could be at your
fingertips. There would be countless uses for computer
screens that could be worn on a sleeve or rolled up and
stuffed in a pocket - an electronic map for tourists, for
example, or a complete set of wiring diagrams for an
engineer working at a remote location. This plastic-silicon
combination could also be used to make speakers,
microphones or a new generation of sensors to spot
pollutants or diagnose disease. Details are given.
CORNELL UNIVERSITYUSA
Accession no.765153
Item 87Biomaterials
21, No.6, 2000, p.629-36
MICROGROOVED SILICONE SUBCUTANEOUSIMPLANTS IN GUINEA PIGSWalboomers X F; Jansen J A
Nijmegen,University
Cell-substratum interactions are of fundamental
importance for the reaction of body tissues to surgically
implanted foreign materials. The influence of 2 mu m
wide microgrooves, with various depths (0.5-6 mu), on
capsule formation around subcutaneous silicone implants,
is investigated in an animal experiment. Silicone sheets
with microtexture are glued around silicone tubes. These
implants are placed subcutaneously in eight guinea pigs
for ten weeks. The implanted tubes are removed including
all surrounding tissues, and processed for light microscopy
and subsequent histomorphometrical evaluation. All
removed implants are surrounded by a thin fibrous
capsule, and it is observed that this capsule is separated
from the implants by a thin, single layer of mono- and
multinucleated phagocytotic cells. In histomorphometry
no significant differences are seen in relation to the
reaction towards the various textures. It is concluded that
microtextures do not have an effect on the morphological
characteristics of capsule formation around silicone
implants in soft tissue. 32 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.765055
Item 88Patent Number: US 5985945 A 19991116
FOAMABLE SILOXANE COMPOSITIONS ANDSILICONE FOAMS PREPARED THEREFROMLoiselle B P; Rapson L J
Dow Corning Corp.
Foamable organosiloxane compositions are disclosed
which yield, upon cure, silicone foams having low density
and decreased friability, comprising a siloxane base
polymer having an average of at least two hydroxyl groups
per molecule, a silicon-containing crosslinker for the
siloxane base polymer, wherein the crosslinker contains
at least two -SiH groups per molecule; a platinum group
catalyst; a silicone resin copolymer; and, optionally, a
blowing agent; and silicone foams prepared therefrom. A
method of weather-stripping a door or window using a
silicone foam so prepared is also disclosed.
USA
Accession no.764891
Item 89Kunststoffe Plast Europe
90, No.2, Feb.2000, p.32-3
SILICONE COMPOSITESPohmer K
The development of innovative self-adhesive liquid
silicones has made it possible, for the first time, to produce
rigid/flexible composites in thermoplastics and silicones
using hardened steel moulds without any coating.
WACKER-CHEMIE GMBHEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.764600
Item 90Pitture e Vernici
76, No.2, 1st-15th Feb.2000, p.31-6
Italian; English
WATER-BASED SILICONE SEALANTS.EVOLUTION OR REVOLUTIONGiraud M Y; Feder M; Dubouis R
Conchem
Various aspects of the water-based silicone sealants
industry are discussed in some detail. Information
presented includes a brief historical review, a brief
comparison of conventional sealants, market research
carried out by Rhone Poulenc, preparation of sealants by
the emulsion polymerisation and by Rhodalis technology
and a comparison of the two methods, and a comparison
with other sealants.
RHONE-POULENC SAEUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.763094
Item 91Medical Device & Diagnostic Industry
Nov.1999, p.38/44
SILICONE RUBBER FOR MEDICAL DEVICEAPPLICATIONS
References and Abstracts
© Copyright 2001Rapra Technology Limited 85
Heide C
Vesta Inc.
A general overview is presented of silicone rubbers,
including information on physical properties, fabrication
methods and potential advantages for medical device
manufacturing. Their chemical structure and curing
mechanisms are also investigated. 4 refs.
USA
Accession no.760269
Item 92156th ACS Rubber Division Meeting - Fall 1999.
Conference preprints.
Orlando, Fl., 21st-23rd Sept.1999, paper 93
SILICA-PDMS INTERACTIONS - A NEW VIEWOF AN OLD QUESTIONBarthel H
Wacker-Chemie GmbH
(ACS,Rubber Div.)
Fumed silica is an amorphous synthetic silicon dioxide
used in a variety of technical applications. Besides free
flow of powders and thickening of liquids, the
reinforcement of silicone elastomers is of main
importance. Mechanisms of reinforcement are still an
issue of scientific discussions. However, it has been settled
that interactions between the silica surface and the
polydimethylsiloxane (PDMS)chain segments play amajor role. Recent efforts to understand those interactions,
both on a molecular and an atom scale level, are reviewed.
Hydroxylated and silylated silicas with defined degree
of silylation are investigated. As an experimental
adsorption technique, inverse gas chromatography, in an
infinite dilution and a finite concentration mode, is used.
Adsorption of linear oligomers of dimethylsiloxy units
reveal that steric factors dominate the energy of
adsorption. On an atom-scale level, a series of
computational studies together with experimental
vibration spectroscopy is performed. Semi-empirical
quantum chemical techniques, basing on AM1 and PM3
parameters, are used to study nanoscale surface facets.
Unspecific, dispersion forces together with induced
dipole-dipole interactions control the adsorption of
PDMS- on fumed silica, and discrete H-bonding are of
minor importance. A review on various results of
structures and interaction energies from different methods
is presented. 35 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.759686
Item 93156th ACS Rubber Division Meeting - Fall 1999.
Conference preprints.
Orlando, Fl., 21st-23rd Sept.1999, paper 73
REVIEW OF MECHANICAL VERSUS MANUALNICKING OF SILICONE RUBBER
Briggs G; Korthals K
Laur Silicone Rubber Compounding Inc.
(ACS,Rubber Div.)
A mechanical nicking device is initially evaluated to see
if there is justification, through testing, for its purchase.
The goal is to achieve more accuracy and precision in the
Tear Die B tests (ASTM D 624). The original test uses
silicone samples of different durometers and three
operators. In this phase, it is shown that the standard
deviation varies less when done by mechanical means.
Research is continued using side by side comparisons on
various materials with actual production lots. A database
is created tracking Tear Die B standard deviation for the
mechanical versus hand nicking. The performance of each
method is reviewed using silicone materials with a range
of durometers. 4 refs.
USA
Accession no.759667
Item 94156th ACS Rubber Division Meeting - Fall 1999.
Conference preprints.
Orlando, Fl., 21st-23rd Sept.1999, paper 72
SILICONE FOAM - CAN IT MEASURE UPSuprenant R; Wolosen M; Larson E; George C
Rhodia Silicones Inc.
(ACS,Rubber Div.)
Silicone foam materials have been available commercially
for many years. The materials have been either heat cured
rubber or RTV (room temperature vulcanised). Emphasis
is placed on RTV preparation of foam, details are given
of the tools needed to develop low density, high strength
properties. The development of analytical tools used in
efforts to produce silicone foam suited to compete with
PU foam are examined. 158 refs.
USA
Accession no.759666
Item 95156th ACS Rubber Division Meeting - Fall 1999.
Conference preprints.
Orlando, Fl., 21st-23rd Sept.1999, paper 69
COMPRESSION SET BEHAVIOUR OFADDITION CURABLE SILICONE RUBBERMeguriya N; Yoshida T
Shin-Etsu Chemical Co.Ltd.
(ACS,Rubber Div.)
Injection moulding of liquid silicone rubber is becoming
increasingly important. Compared to conventional
compression moulding, liquid injection moulding systems
(LIMS) can be moulded at a much faster pace and
accuracy, required for less steps, which reduces labour
cost and improves productivity. LIMS material has
superior purity and clarity as well as low odour and neutral
taste because it is cured through addition (hydrosilylation)
References and Abstracts
86 © Copyright 2001 Rapra Technology Limited
reaction, so that no by-products are produced and the
whole process goes in closed system. They can also be
produced fully automatically (no runners, flashless, auto-
ejection) if the system is designed properly. Silicone
rubber is used in many fields for their various properties
not available in any other organic rubbers. Compression
set of silicone rubber is very low and varies little -50 deg.C
to 200 deg.C, compared to organic rubbers which are not
suitable for use as sealing materials at their extreme
temperature.
JAPAN
Accession no.759663
Item 96Philadelphia, PA, 1998, pp.18. NALOAN.
MIL-I-46852. INSULATION TAPE,ELECTRICAL, SELF ADHERINGUNSUPPORTED SILICONE RUBBERUS Military
MIL-I-46852
Version C Notice 1. Superseded by A-A-59163 on 13/2/
98. Photocopies and loans of this document are not
available from Rapra.
USA
Accession no.759594
Item 97156th ACS Rubber Division Meeting - Fall 1999.
Conference preprints.
Orlando, Fl., 21st-23rd Sept.1999, paper 68
NEW TRENDS IN SILICONE ELASTOMERTECHNOLOGYBurkus F S; Amarasekera J
General Electric Silicones
(ACS,Rubber Div.)
The trend to high performance, long lasting industrial
subsystems is driving the need for high-performance
elastomers. A high performance elastomer should maintain
material integrity while being exposed to harsh
environmental conditions including thermal cycling,
solvent and chemical exposure, high pressures and high
stress environments. Silicone elastomers are the materials
of choice for such applications and have inherent benefits
when compared to standard organic elastomers. These
properties are described, and compared and contrasted with
those of other elastomeric systems. New material
developments and processing techniques have resulted in
the use of silicone elastomers in applications previously
unattainable. These new material developments are
discussed, as is the process of liquid injection moulding of
elastomers with an emphasis on product design, the
structures of the siloxanes used, the productivity of the
process and the properties of the resulting elastomer. 6 refs.
USA
Accession no.758361
Item 98Journal of Thermal Analysis and Calorimetry
57, No.1, 1999, p.323-8
DEVELOPMENT OF A NEW SILICONE BASETRANSDERMAL SYSTEM. III. STUDY OFTHERMAL PROPERTIES OF SILICONEELASTOMERS CONTAINING LIQUIDINGREDIENTSWagner O; Kenessey G; Liptay G
Budapest,Technical University; MOL Hungarian Oil &
Gas Co.
Commonly-used base silicone elastomers for transdermal
therapeutic systems, i.e. cured polydimethylsiloxanes,
were studied with particular reference to the change of
the inner polarity of silicone elastomers containing various
amounts of polar liquid ingredients and trifunctional
silicone additives. It was shown that the polarity of the
inside of the matrix was related to the diffusion properties
of model substances and thermal properties of silicone
elastomers. The ingredients used changed the matrix
framework, which was also influenced by the type of
trifunctional additive. These properties were markedly
dependent on the timing of the measurement.
Measurements carried out after 48 hours of the production
of the polymer showed reproducible properties, indicating
that the final structure of the polymer was formed. These
results showed that the ingredients influenced the
properties of the silicone matrices significantly, so that
the characteristics of drug release from pharmaceutical
forms could also be varied. 10 refs.
EASTERN EUROPE; HUNGARY
Accession no.755874
Item 99Adhasion Kleben & Dichten
41, No.9, 1997, p.26/32
German
FOAMING OR FOAMABLE SEALS (PART I)?Kayed J
Wil SG (Schweiz)
Foam-in-place seals promise great savings in costs
compared with pre-formed sealing elements. The market
offers different methods and materials, so that the most
varied problem definitions can be solved. First aid to help
decide on the choice of the right system is given in this
article. Part II of this contribution, published in the next
edition (Oct.1997), surveys the properties of starting
materials and completed seals as well as special technical
processes. A list of references appears in the 1997 October
issue. Technical aspects here cover foaming polyurethane
mechanisms and silicones, as well as chemically foaming
seals, physically foamable seals and hot melts for foam-
in-place seals, including temperature and air moisture as
processing parameters.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
SWITZERLAND; WESTERN EUROPE
Accession no.754449
References and Abstracts
© Copyright 2001Rapra Technology Limited 87
Item 100Rubber and Plastics News
29, No.5, 4th Oct.1999, p.6
SURGICAL METHODS IMPACTINGPROCESSORSBoyd J
Trends in surgical procedures have led to the increased
use of minimally invasive surgical procedures in place of
traditional ‘open body’ methods for operations such as
gall bladder surgery, hysterectomies and appendectomies.
These techniques are creating opportunities for silicone
rubber processors, since silicone rubber offers advantages
over other materials such as PVC, latex and polyurethanes
in terms of biocompatibility and processability. Problems
with latex allergies, and perceived potential hazards with
PVC are leading to their replacement with silicone rubber
medical equipment, including long-term implants such
as pacemakers.
USA
Accession no.753319
Item 101Rubber Chemistry and Technology
72, No.1, March-April 1999, p.152-164
BASIC STUDY OF CONTINUOUS ULTRASONICDEVULCANISATION OF UNFILLED SILICONERUBBERDiao B; Isayev A I; Levin V Y
Akron,University
Prepared samples of a peroxide cured silicone rubber were
devulcanised by passing through an extruder fitted with
an ultrasonic die at different throughput rates and back
pressures. A branched structure in the network of the
devulcanised material, the degree of which depends on
the amplitude of the ultrasonic waves, is indicated.
Assessment of amount of devulcanisation was made with
gel fraction and crosslink density measurements. The
devulcanised samples were then revulcanised with further
peroxide, both alone and blended with fresh silicone
rubber. Mechanical properties of the revulcanised samples
were compared with both the original vulcanised samples
and those prepared from a blend of devulcanised and fresh
material. Indications are that a blend of devulcanised and
fresh material has similar tensile but higher elongation
than virgin material. (Originally presented to ACS
meeting, Cleveland, Oct 21-24, 1997, revised May 98)
17 refs
USA
Accession no.753130
Item 102Plastics Technology
No.10, Oct.1999, p.54/61
LIQUID INJECTION MOLDING HITS ITSSTRIDEOgando J
Growth in the use of liquid injection moulding as a
processing method is examined, as suppliers in North
America report sales growth in liquid silicone rubber in
excess of 10% a year, and producers of liquid injection
moulding machines also report a similar picture of double
digit growth. Trends and developments driving this growth
are discussed, and include the ability to mould bigger parts,
the availability of higher mould cavitation, gas-assist
moulding, the possibility to produce dual-durometer parts
and thermoset/thermoplastic combinations. Developments
in machinery are reviewed with details of specific
machines.
NORTH AMERICA
Accession no.752983
Item 103European Coatings Journal
No.10, 1999, p.26/42
SILICONES FOR WATERBORNE WOODCOATINGSEaston T; Cackovich A
Dow Corning Europe
The aim of this paper is to demonstrate the versatility of
silicone technology in meeting the demands of wood
coatings. The choice of a suitable additive or combination
thereof, are shown to provide improved surface lubricity,
gloss, levelling, blocking and chemical resistance. Details
are given of new chemical structures and delivery forms
of silicone which provide better performance in water
based wood coatings. Physical and chemical modification
techniques are discussed for polydimethyl siloxane. 4 refs.
EUROPE-GENERAL
Accession no.751612
Item 104155th ACS Rubber Division Meeting, Spring 1999.
Conference Preprints.
Chicago, Il., 13th-16th April 1999, Paper 83, pp.16
CLOSED LOOP FUZZY CONTROL OF PARTWEIGHT IN INJECTION MOLDING OF LIQUIDSILICONE RUBBER (LSR) BASED ON PVTBEHAVIORHaberstroh E; Henze E
IKV
(ACS,Rubber Div.)
A closed loop system based on pressure-volume-
temperature behaviour for the control of part weight in
the injection moulding of liquid silicone rubber is
described. Depending on the course of cavity pressure
and mould temperature, a fuzzy logic based algorithm
determines the required changes in dosing volume in the
case of process disturbances and ensures a constant part
weight. 3 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
USA; WESTERN EUROPE
Accession no.749893
References and Abstracts
88 © Copyright 2001 Rapra Technology Limited
Item 105155th ACS Rubber Division Meeting, Spring 1999.
Conference Preprints.
Chicago, Il., 13th-16th April 1999, Paper 80, pp.18
MULTI-COMPONENT INJECTION MOLDINGOF RIGID-FLEXIBLE COMBINATIONS MADEFROM THERMOPLASTICS, RUBBER ANDLIQUID SILICONE RUBBERRonnewinkel C; Haberstroh E
IKV
(ACS,Rubber Div.)
Factors influencing adhesion between rubber and
thermoplastic components in parts produced by two-
material injection moulding are examined. Results are
presented of studies undertaken to optimise adhesion in
parts produced by this technique from liquid silicone
rubber and polyamides or PBTP. 22 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
USA; WESTERN EUROPE
Accession no.749891
Item 106Patent Number: US 5952403 A 19990914
MEDICAL ELECTRICAL LEAD ANDREINFORCED SILICONE ELASTOMERCOMPOSITIONS USEDPaulsen M J; Miller J P; Ebert M J
Medtronic Inc.
A medical electrical lead and a reinforced silicone
elastomer used therein. The silicone elastomer used is
preferably made from a novel silica reinforced
polysiloxane material, which after vulcanisation by cross-
linking exhibits improved mechanical properties. The
medical electrical lead features an electrode at a distal
end thereof and an elongated electrical conductor
extending between the electrode and the connector, the
conductor in electrical contact with the electrode at a distal
end and in electrical contact with the electrode at a distal
end, the conductor comprised of several wires or wire
bundles wound in a multifilar coil configuration.
USA
Accession no.749726
Item 107Patent Number: US 5952397 A 19990914
PHOTO-CURABLE LIQUID SILICONE RUBBERCOMPOSITIONS FOR TEMPLATING MOTHERMOLDSFujiki H; Sakamoto T
Shin-Etsu Chemical Co.Ltd.
A photo-curable liquid silicone rubber composition is
curable upon exposure to light into a cured product having
a Shore A hardness of 20-60 and a light transmittance of
at least 10% at a wall gauge of 10 mm. The composition
is suitable for forming a transparent templating mother
mould which allows a photo-curable liquid resin cast
therein to be cured with light transmitted by the mould
wall.
JAPAN
Accession no.749721
Item 108Patent Number: US 5858287 A 19990112
EXTRUSION METHOD OF PRODUCING APOLYMERIC SEALING/SPRING STRIPScott M K
Crane Plastics Co.Ltd.
The present invention pertains to a polymeric sealing/
spring strip and method of producing the same. The
polymeric strip has various embodiments which are based
upon the incorporation of silicone rubber. Some of the
embodiments are based on the formation of a resilient
silicone rubber surface to provide a sealing/spring contact
with an opposing surface period. Other embodiments
incorporate the silicone rubber in such ways as to utilise
its resilient properties to produce a sealing/spring strip
which has improved mechanical resilience properties. The
method allows the production of a sealing/spring strip in
accordance with the present invention by using extrusion
techniques.
USA
Accession no.746980
Item 109Polymer Bulletin
42, No.6, July 1999, p.717-24
SOLID PARTICLE EROSION OFELECTRICALLY INSULATING SILICONE ANDEPDM RUBBER COMPOUNDSBesztercey G; Karger-Kocsis J; Szaplonczay P
Furukawa Electric Institute of Technology; Institut fuer
Verbundwerkstoffe GmbH; Kaiserslautern,University;
Furukawa Composite Insulators
A study was made of the particle jet erosion behaviour of
outdoor insulating silicone and EPDM rubber
compositions subjected to sandblasting. The effects of
impact angle and amount of non-reinforcing filler
(alumina trihydrate) and the wettability of the sandblasted,
contaminated silicone rubber surfaces in the incubation
period are discussed. 8 refs.
EASTERN EUROPE; EUROPEAN COMMUNITY; EUROPEAN
UNION; GERMANY; HUNGARY; WESTERN EUROPE
Accession no.745933
Item 110Patent Number: US 5919437 A 19990706
COSMETIC CREAM COMPOSITIONCONTAINING SILICONE GEL MATERIALLee W; Bianchini R J; Hilliard P J
Colgate-Palmolive Co.
References and Abstracts
© Copyright 2001Rapra Technology Limited 89
Disclosed is a solid cosmetic composition (e.g. a cream
composition) containing an active cosmetic material (e.g.
a deodorant active, an antiperspirant active, a sunscreen,
an insect repellent and/or an anti-fungal agent) and a
silicone gel material. The silicone gel material includes
(a) a volatile silicone material and (b) an
organopolysiloxane material as a gelling agent, able to
form a gel after being mixed with the volatile silicone
material. The organopolysiloxane material can be a
reaction product of a vinyl-terminated siloxane polymer
and a hydride crosslinking agent. The composition can
be formed by mixing the active cosmetic material and
silicone gel material at ambient temperature. The
compositions do not need particulate or clay thickeners
or waxy gelling agents.
USA
Accession no.745873
Item 111Rubber and Plastics News
28, No.24, 28th June 1999, p.1/21
STUDY FINDS BREAST IMPLANTS DON’TCAUSE ILLNESSMoore M
Silicone gel breast implants do not cause cancer or
systemic disease in women, according to a government-
funded study. But other complications, such as implant
rupture and deflation or contraction of the fibrous tissue
around the breast, are fairly common and need to be
studied further, concluded the three-member panel
organised under the auspices of the Institute of Medicine,
the medical arm of the National Academy of Sciences.
Dow Corning, inventor of silicone implants, said the
report ‘provides additional solid evidence that breast
implants do not cause disease’. The panelists, who have
no connection with any parties in the silicone implant
dispute and worked without compensation, reviewed more
than 3,000 publications on implants, giving particular
weight to peer-reviewed scientific articles. All the
evidence indicates that rupture, tissue contraction and
other local complications resulting in pain, disfigurement
or infection are the main problems with silicone implants,
according to the study. Details are given.
US,NATIONAL ACADEMY OF SCIENCES;
US,INSTITUTE OF MEDICINE; DOW CORNING
CORP.USA
Accession no.745570
Item 112Patent Number: EP 939103 A2 19990901
SILICONE RUBBER COMPOSITIONBaba K; Hirai K; Matsushita T
Dow Corning Toray Silicone Co.Ltd.
This comprises a polyorganosiloxane gum of given
formula, microparticulate silica and a methyl-substituted
benzoyl peroxide having a maximum grain diameter not
exceeding 50 micrometers and an average grain diameter
of 30 micrometers. When cured, it exhibits reduced non-
uniformity in the physical properties because of fewer
voids, resulting in decreased frequency of spark-outs in
insulated wires.
JAPAN
Accession no.744615
Item 113Patent Number: US 5889109 A 19990330
SILICONE RUBBERS WITH IMPROVED MOLDRELEASE PROPERTIESKnies W; Guske W
Wacker-Chemie GmbH
The invention relates to polyorganosiloxane rubber
compositions which vulcanise to elastomers under the
influence of heat and comprise: (A) 100 parts by weight
of organopolysiloxane; (B) 10 to 200 parts by weight of
filler; (C) 0.1 to 10 parts by weight of crosslinking agent
which forms free radicals; and (D) 0.05 to 10 parts by
weight of aliphatic alcohol with C8 to C30 alkyl radicals.
The aliphatic alcohol (D) acts as an internal mould release
agent.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.744249
Item 114Patent Number: US 5886111 A 19990323
SILICONE SEALING MATERIAL EXHIBITINGHIGH STRESS RELAXATIONChiotis A; Wojtowicz J
Raychem Corp.
A silicone gel formulation is described having a Voland
hardness of from about 6 to 30 grams, a tack of from
about 17 to 35 grams, and a stress relaxation greater than
50%. The material is especially suitable for sealing the
back end of connectors containing a multiple of fine wires
with gauges between about 14 gauge and 28 gauge. It is
particularly suitable to seal the back end of an automotive
connector subjected to a wide variety of harsh
environmental conditions.
USA
Accession no.741955
Item 115Patent Number: US 5911711 A 19990615
LUBRICANT SYSTEM FOR HYPODERMICNEEDLES AND METHOD FOR ITSAPPLICATIONPelkey B J
Becton,Dickinson & Co.
A lubricious coating having a first layer formed from at
least a partially cured organosiloxane copolymer and
References and Abstracts
90 © Copyright 2001 Rapra Technology Limited
PDMS having a viscosity greater than about 1,000
centistokes and a second layer including PDMS having a
viscosity between about 50 and 350 centistokes is applied
to and adherent to the outside surface of the elongate tube
of the hypodermic needle.
USA
Accession no.741175
Item 116Patent Number: US 5911317 A 19990615
LIGHT PERMEABLE METAL PLATED RUBBERKEYTsai J
Silitek Corp.
The key is made of silicone rubber and has a hardened
head on top printed with light-permeable ink. The key is
metal plated and replaces rubber keys and keys with
adhered rubber and silicone rubber.
TAIWAN
Accession no.741173
Item 117Patent Number: US 5814259 A 19980929
METHOD FOR MOULDING STRUCTURALPARTS UTILISING MODIFIED SILICONERUBBERWeiser E S; Baucom R M; Snoha J J
US,National Aeronautics & Space Administration
This invention improves upon a method for moulding
structural parts from preform material. Preform material
to be used for the part is provided. A silicone rubber
composition containing entrained air voids is prepared.
The silicone rubber and preform material assembly is
situated within a rigid mould cavity used to shape the
preform material to the desired shape. The entire assembly
is heated in a standard heating device so that the thermal
expansion of the silicone rubber exerts the pressure
necessary to force the preform material into contact with
the mould container. The introduction of discrete air voids
into the silicone rubber allows for accurately controlled
pressure application on the preform material at the cure
temperature.
USA
Accession no.740203
Item 118Kunststoffe Synthetics
No.1, 1998, p.12-4
German
NEW USES WAITING FOR DISCOVERYPohmer K; Spirig N
Bayer AG; Lonstroff AG
Silicone rubbers have an average growth rate of 5%. They
can be injection moulded with a special mix and dosing
technology. Easily processable, they can be made into
combinations with thermoplastics into a range of
applications from babies’ dummies and the membranes
in breathing masks, to long-wave stabilizers, gaskets for
irons, percolators, dishwashers and washing machines.
In combined materials the usual processing temperature
is 180-230C but this becomes much less in combinations
using liquid silicone rubber (LSR). LSR has a heat
stability to 200C, cold flexibility to -50C, good
mechanical properties over a long time, chemical
resistance and electrical and thermal isolation. Combined
with thermoplastics, LSR is also used in hair-dryer
diffusers. There are 2,000 LSR parts in the average car. 4
refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.739935
Item 119Rubber World
220, No.3, June 1999, p.35-7
COINJECTION MOULDING FOR LIQUIDSILICONE RUBBERTimmerman J
Engel GmbH
Coinjection moulding is an exciting new process for the
moulding of liquid silicone rubber that opens up new
possibilities. Coinjection involves injecting two or more
similar materials into the mould cavity together. One
material forms the skin and the other forms the core. The
process is described, together with equipment
requirements and design considerations.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.739157
Item 120Muanyag es Gumi
36, No.2, Feb.1999, p.45-56
Hungarian
HEAT-CURING SILICONE RUBBERSNagy J; Roth Gy
Budapest,Technical University
The authors review heat-curing solid and liquid silicone
rubbers, with particular regard to the properties,
processing characteristics and wide applicability of this
group of elastomers. 14 refs. Articles from this journal
can be requested for translation by subscribers to the Rapra
produced International Polymer Science and Technology.
EASTERN EUROPE; HUNGARY
Accession no.738759
Item 121Adhesive Technology
16, No.2, June 1999, p.31
UNDER PRESSUREGreene K
References and Abstracts
© Copyright 2001Rapra Technology Limited 91
Adhesive Research Inc.
Adhesives play multiple roles in the construction of airbag
inflators. Adhesive Research first supplied adhesives to
the airbag industry when Seal Methods encountered a
problem with its acrylic adhesive system which was
releasing combustible gases during inflation. It was
determined that silicones, with their thermal stability, low
outgassing characteristics and capacity for a tight,
hermetic seal, were most promising.
USA
Accession no.735653
Item 122Journal of Biomedical Materials Research (Applied
Biomaterials)
48, No.3, 1999, p.354-64
SILICONE GEL BREAST IMPLANT FAILUREAND FREQUENCY OF ADDITIONALSURGERIES: ANALYSIS OF 35 STUDIESREPORTING EXAMINATION OF MORE THAN8,000 EXPLANTSMarotta J S; Widenhouse C W; Habal M B; Goldberg E P
Florida,University; Tampa Bay,Craniofacial & Plastic
Surgery Center
Although it is well known that silicone gel breast implants
(SGBIs) produce many local complications and
necessitate frequent surgical revisions, no large cohortretrospective quantitative analysis of clinical data has been
reported to date, especially for the prevalence of failures
and additional surgeries. Data from 35 different studies
that encompass more than 8,000 explanted SGBIs are
analysed and reported. Because examination of a
prosthesis when explanted is the definitive method for
determining shell integrity, the only studies used are ones
that report implant duration, the total number of SGBIs
explanted and the number of SGBIs for which shell
rupture or failure (not intact) is confirmed upon surgical
removal. An exponential regression plot of data indicates
a direct correlation of implant duration with percent shell
failure. SGBI failure is found to be 30% at 5 years, 50%
at 10 years and 70% at 17 years. The failure rate is 6%/
year during the first five years following primary implant
surgery. ANOVA comparison of three implant age groups
(mean implant durations of 3.9, 10.2 and 18.9 years)
indicates a highly significant statistical correlation of
percent failure with implant duration. Complications
necessitating at least one additional surgery occur for 33%
of implants within six years following primary implant
surgery. Shell failure is found to be an order of magnitude
greater than the 4 to 6% rupture prevalence suggested by
the AMA Council on Scientific Affairs in 1993, the 0.2 to
1.1 % cited by manufacturers at that time and the 5%
rupture that was stated to be ‘not a safety standard that
the FDA can accept’. 71 refs.
USA
Accession no.734781
Item 123International Rubber Exhibition and Conference 1999.
Conference proceedings.
Manchester, 7th-10th June 1999, Materials paper 1.
BENEFITS OF SILICONE ELASTOMERS INAUTOMOTIVE APPLICATIONSYouren J
Dow Corning Ltd.
(Crain Communications Ltd.)
Automotive engines have become increasingly complex
and powerful and the engine compartment more crowded.
This has resulted in higher temperatures and more
aggressive environments for rubber components. These
changes have resulted in increasing use of silicone
elastomers for a variety of engine seals covering fuel and
oil applications, ignition components and dynamic seals.
Increasing safety requirements together with
miniaturisation has resulted in silicones being widely used
in airbag production rather than organic rubbers. Many
of the above applications are described, together with the
use of existing and new product and process technologies
to make today’s silicone automotive components.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.734464
Item 124Antec ’99. Volume III. Conference proceedings.
New York City, 2nd-6th May 1999, p.2934-7. 012
SELECTION OF SILICONE SEALANTS FORHEAVY TRUCK AND OFF-ROAD VEHICLEAPPLICATIONSBrennan J E; DiPaola D J
Texas Instruments Inc.
(SPE)
The unique sealing requirements encountered in heavy
truck and off-the-road vehicle applications warrant the
investigation of silicone sealants for this marketplace. The
candidate sealants are subjected to a selection protocol
based on lap shear strength as a function of cure time and
after immersion in water, engine wash fluid and common
automotive fluids. An acid cure silicone does not adhere
well to chromate plated steel, and its adhesion to brass
deteriorates after fluid immersions. A neutral cure silicone
adheres well on any of the substrates, and retains adhesion
after fluid immersions. Neutral cure materials are
recognised as the best choice for future product
performance testing. 3 refs.
USA
Accession no.734271
Item 125Antec ’99. Volume 1. Conference proceedings.
New York City, 2nd-6th May,1999, p.539-44. 012
COMBINING LIQUID-SILICONE-RUBBERSWITH THERMOPLASTICS TO RIGID-
References and Abstracts
92 © Copyright 2001 Rapra Technology Limited
FLEXIBLE COMBINATIONS USING 2-COMPONENT INJECTION MOULDINGRonnewinkel C; Haberstroh E
Institute for Plastics Processing
(SPE)
The production of components consisting of flexible
silicone rubber bonded to rigid thermoplastics using two-
component injection moulding techniques is discussed.
The strength of the bond at the interface between a
polyamide and silicone rubber was investigated using an
injection moulded tensile test bar. It was concluded that
such components could replace rubber-metal
combinations for certain applications. 15 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.732951
Item 126Adhesives & Sealants Industry
6, No.3, April 1999, p.38-9
PSAS INCREASE SAFETY ANDEFFECTIVENESS OF AIRBAG INFLATORS
Adhesives Research and Seal Methods have jointly
developed a new generation of pressure sensitive adhesive-
component solutions for automotive airbag inflator
applications. In general, adhesives for airbag inflators serve
to position and set the airbag in place, hermetically seal the
propellant and attach the propellant cover. It was determinedthat silicones, with their thermal stability, low outgassing
and capacity for a tight hermetic seal, were most promising.
ADHESIVES RESEARCH INC.; SEAL METHODS
INC.USA
Accession no.731126
Item 127Kauchuk i Rezina (USSR)
No.6, 1998, p.10-6
Russian
ELECTRICAL CONDUCTIVITY OF FLEXIBLEMATERIALSZuev Yu S
A review is presented of recent studies on the effect of
various factors on the electrical conductivity and volume
resistivity of polymeric systems, also covering the effect
of plasticisers and fillers on the volume resistivity, and
the anomalously low resistivity of black-filled fluorine-
containing rubbers and silicone rubber. Flexible materials
(vulcanisates, thermoplastic elastomers, sealants and
others) are classified in terms of their resistivity. 72 refs.
Articles from this journal can be requested for translation
by subscribers to the Rapra produced International
Polymer Science and Technology.
RUSSIA
Accession no.726960
Item 128Journal of Biomedical Materials Research
45, No.3, 5th Jun.1999, p.240-50
SHEEP, PIG, AND HUMAN PLATELET-MATERIAL INTERACTIONS WITH MODELCARDIOVASCULAR BIOMATERIALSGoodman S L
Connecticut,University
The haemocompatibility of pyrolytic carbon mechanical
heart valve leaflets, PE, and silicone rubber was examined.
Data are given for ovine, porcine and human platelets.
49 refs.
USA
Accession no.726766
Item 129China Synthetic Rubber Industry
22, No.2, Mar.1999, p.70-3
Chinese
ADVANCES IN ADDITION SILICONE RUBBERTan Bi’en; Pan Huiming; Wang Weixing; Zhang
Lianzheng; Zhao Feiming
South China,University of Technology;
Beijing,Aerospace Institute of Materials & Processing
Technology
Advantages in research of addition silicone rubber in high
strength, high heat resistance and addition injectionmoulding were reviewed. 18 refs.
CHINA
Accession no.726408
Item 130Kauchuk i Rezina (USSR)
No.5, 1998, p.33-6
Russian
METHOD OF CALCULATING THE FREE PLAYOF A SEAL OPERATING OVER A WIDETEMPERATURE RANGEShindler V M; Khalo T P
A method is described for calculating the required
tightness of fit of seals based on siloxane rubbers operating
in widely varying temperature conditions. 6 refs. Articles
from this journal can be requested for translation by
subscribers to the Rapra produced International Polymer
Science and Technology.
RUSSIA
Accession no.723338
Item 131Revue Generale des Caoutchoucs et Plastiques
No.769, June/July 1998, p.66/73
French
HIGH TEMPERATURE VULCANISINGELASTOMERS IN THE BIOMEDICAL SECTOR
References and Abstracts
© Copyright 2001Rapra Technology Limited 93
Leuci C
Rhodia Silicones
The structure, properties and biomedical applications of
high temperature vulcanising silicone rubbers are
examined. The conformity of Rhodia Silicones’ Silbione
silicone rubbers with European and US regulations
covering such applications is discussed, and results are
presented of studies of the behaviour of these elastomers
when subjected to different sterilisation techniques. 6 refs.
EU; EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
USA; WESTERN EUROPE; WESTERN EUROPE-GENERAL
Accession no.721744
Item 132Kunststoffe Plast Europe
89, No.1, Jan.1999, p.20-3; p.68/72
RELIABLE PROCESSING OF LIQUIDSILICONE RUBBER (LSR) INTO TECHNICALMOULDINGSHaberstroh E; Henze E; Ronnewinkel C
In a number of research projects, the IKV is working
intensively with raw material and machine manufacturers
as well as the processing industry on technologies for
processing LSR. These activities are concentrating on process
analysis and process development for injection moulding.
Aspects covered include control of the quality of the
moulding, process sequences in the pvT diagram, fuzzy logic
for control of moulding weight, function of the fuzzycontroller, effect of the control system, simulation of the
flow and curing behaviour, multi-component injection
moulding of LSR thermoplastic combinations, polyamide/
LSR composites and production of LSR components with
functional cavities using the gas injection technique. 9 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.719224
Item 133Biomaterials
20, No.3, Feb. 1999, p.291-9
EVALUATION OF THE IN VITROBIOCOMPATIBILITY OF VARIOUSELASTOMERSChauvel-Lebret D J; Pellen-Mussi P; Auroy P;
Bonnaure-Mallet M
Rennes,Universite
An evaluation is presented of the in vitro biocompatibility
of silicone-based rubbers. The dimethylthiazol
diphenyltetrazolium bromide colorimetric test was used
to assess cell viability and flow cytometry was used to
evaluate cell proliferation. Changes in cell morphology
were examined using SEM. Comparisons were made with
PU and PS toxicity controls. 28 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.714416
Item 134ACS Polymeric Materials Science and Engineering.
Fall Meeting 1998. Volume 79. Conference
proceedings.
Boston, Mas., 23rd-27th Aug.1998, p.522. 012
ELASTOMERS FOR IMPLANTABLEAPPLICATIONS - SILICONE ORPOLYURETHANE ?Skalsky M
Elastomedic Pty.Ltd.
Medical device developers have had a very limited choice
of implant materials for highly demanding applications
such as insulation for pacing leads, long term in-dwelling
catheters, synthetic polymer heart valves and coronary
vascular grafts. All of these applications require polymers
with excellent biostability, good mechanical strength and
high resistance to fatigue, abrasion and tear. Traditionally,
silicone rubber was the first material of choice, because
of its excellent biostability, despite shortcomings in the
other material properties. PU, a generic name for a very
large family of synthetic polymers, has emerged as the
principal alternative to silicone rubber because of superior
mechanical properties. 7 refs.
AUSTRALIA
Accession no.713300
Item 135ACS Polymeric Materials Science and Engineering.
Fall Meeting 1998. Volume 79. Conference
proceedings.
Boston, Mas., 23rd-27th Aug.1998, p.514. 012
CHEMISTRY OF SILICONE BASEDBIOMATERIALS AND WHY THEY CONTINUETO BE MATERIALS OF CHOICE FORHEALTHCARE APPLICATIONSPetraitis D J
NuSil Technology
Since their early inception, materials based on silicone
polymers have been characterised by their chemical
inertness. Early silicone materials included greases which
were formulated for insulating electrical ignition systems
used by the military during World War II. Although their
resistance characteristics were primarily concerned with
weathering and other environmental factors such as ozone
and high temperatures, this unique inertness of silicone
polymer based materials ultimately evolved into
biomedical applications. Silicone based materials were
found to be extraordinarily inert to the chemicals present
in biosystems. Silicones are among the most
biocompatible materials known to man and today continue
to outperform other materials in biomedical applications
including applications in such diverse products as
pacemaker leads, intraocular lenses, long and short term
catheter and shunt implants, finger joint implants, as well
as greases, lubricants, encapsulants and adhesives used
in the fabrication, assembly or actual performance of an
endless and continuing to be developed group of
References and Abstracts
94 © Copyright 2001 Rapra Technology Limited
healthcare applications. The basic chemistry involved in
the synthesis of silicone polymers and subsequent product
formulations into elastomers, pressure-sensitive
adhesives, marking inks, fluids and lubricants are
discussed.
USA
Accession no.713295
Item 136Gummi Fasern Kunststoffe
50, No.12, Dec. 1997, p.967-73
German
APPLICATION OF FOAM-IN-PLACE GASKETSKayed J
Instead of prefabricated shaped gaskets physically
manufactured by stamping, injection moulding, extrusion
etc., chemico-technical systems can be employed for the
inline manufacture of precision gaskets (Foam-in-Place
with partial or complete automation). This technique uses
one-, two- or multi-component materials with the help of
mixing and/or metering machines in the low-pressure range.
The fluid compound applied produces a foam gasket with
modifiable physical and chemical properties. At the same
time the adhesion can be adjusted as required, from very
high to zero or near zero. Data are given on the foaming
mechanisms of polyurethanes, silicones and hotmelts for
foam-in-place gaskets. 8 refs. Articles from this journal
can be requested for translation by subscribers to the Rapra
produced International Polymer Science and Technology.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.713240
Item 137Rubber Technology International
1998, p.22-5
SILICONE RUBBER FOR ELECTRICALINSULATORSGoudie J
Dow Corning Corp.
The market for composite insulators is growing steadily.
Composite designs generally employ a fibreglass rod or
hollow core for mechanical strength, with an outer housing
made from either silicone rubber, EPDM or EPR. Insulator
service life can be affected by electrical, mechanical and
environmental stresses. One of the biggest problems in
outdoor applications is airborne contamination that settles
on the insulator surface. The surface of a silicone elastomer
has a unique ability to interact with the contaminant and
control leakage currents. 6 refs.
USA
Accession no.713200
Item 138IRC ’98. Conference Proceedings.
Paris, 12th-14th May 1998, p.321-6. 012
French
APPLICATIONS OF SILICONES IN ARTPujol J M
Rhodia Silicones
(AFICEP; Societe de Chimie Industrielle)
Applications of silicone rubbers in moulds for the
reproduction of works of art and in the assembly of glass
objects and repair of stained glass windows are
described. The use of silicone resins in the protection
and restoration of ancient buildings and monuments is
also examined. 1 ref.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.710626
Item 139Gummi Fasern Kunststoffe
50, No.5, May 1997, p.376-85
German
ROLLS AND ROLLERSZeppernick F
A historical survey is given of the development and use
of polyurethane rubber in rollers and roller coatings, and
of coating of rolls with silicone rubber. Articles from this
journal can be requested for translation by subscribers to
the Rapra produced International Polymer Science and
Technology.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.710477
Item 140Polimery Tworzywa Wielkoczasteczkowe
42, No.5, 1997, p.288-93
Polish
C0NTRIBUTION OF RESEARCH ANDEXPERIMENTAL PRODUCTION AT ICRI TOTHE DISSEMINATION OF SILICONEAPPLICATIONS IN POLANDRosciszewski P; Maciejewski J; Zielecka M; Miazga A;
Paczka J; Porcja I
Warsaw,Industrial Chemistry Research Institute
A historical account is given of the research and development
work carried out on the principal types of silicones that have
been successfully commercialised at the Industrial Chemistry
Research Institute’s Silicone Pilot Plant and at the Organika-
Sarzyna Chemical Works. This includes work on fluids,
emulsions, compounds, resins, varnishes, release agents,
water-repellents for textiles and masonry, adhesives,
antifoaming agents, and room-temperature vulcanising
rubbers. 46 refs. Articles from this journal can be requested
for translation by subscribers to the Rapra produced
International Polymer Science and Technology.
EASTERN EUROPE; POLAND
Accession no.710463
References and Abstracts
© Copyright 2001Rapra Technology Limited 95
Item 141Analytical Chemistry
70, No.23, 1st Dec.1998, p.4974-84
RAPID PROTOTYPING OF MICROFLUIDICSYSTEMS INPOLYDIMETHYLSILOXANE(PDMS)Duffy D C; McDonald J C; Schueller O J A; Whitesides G M
Harvard University
A procedure was developed for designing and fabricating
(including sealing) microfluidic systems in an elastomeric
material (PDMS) in less than 24 h. A network of microfluidic
channels was designed in a CAD program. This design was
converted into a transparency by a high-resolution printer
and this transparency was used as a mask in photolithography
to create a master in positive relief photoresist. PDMS cast
against the master yielded a polymeric replica containing a
network of channels. The surface of this replica and that of a
flat slab of PDMS were oxidised in an oxygen plasma and
these oxidised surfaces were shown to seal tightly and
irreversibly when brought into conformal contact. 88 refs.
USA
Accession no.709681
Item 142Patent Number: US 5741877 A 19980421
SILICONE PSEUDOGELTiffany J S
A silicone gel-like material having reduced content of
extractable silicone fluid and having rheological properties
approximating human tissue. The gel-like material or
“pseudogel” is useful for filling an implantable prosthesis.
Prior art silicone gel-filled prosthetic implants contain a
high proportion of extractable free silicone fluid. The free
silicone fluid within an implant may enter the host’s body
by diffusion through the prosthetic shell or by rupture of
the outer envelope of the prosthesis. The present filler
material, or pseudogel, is produced by controlling the
crosslinking of the silicone polymer network such that every
polymer chain contains only terminal reactive vinyl groups
but not all of the reactive groups participate in the
crosslinking reaction. In a preferred embodiment, the
polymeric vinyl-terminated starting fluids are selected so
that the average molecular weights of the polysiloxane
polymers comprising the fluid may fall into two or three
distinct ranges. The crosslinker, which is composed of a
siloxane molecule containing silicone hydride groups, is
selected to have relatively high Si-H content. By controlling
the crosslinker concentration, essentially all the chains can
be made to react, but in such a way that chains are only
reacted at one end and functional as non-extractable diluents
between the crosslinked longer chains. The resulting
pseudogel exhibits low extractability and is suitable for
filling a soft-tissue prosthesis such as a breast prosthesis
having a flexible outer shell which contains the pseudogel.
USA
Accession no.707845
Item 143Journal of Biomedical Materials Research
42, No.4, 15th Dec.1998, p.485-90
CYTOTOXICITY TESTING OF MATERIALSWITH LIMITED IN VIVO EXPOSURE ISAFFECTED BY THE DURATION OF CELL-MATERIAL CONTACTCiapetti G; Granchi D; Stea S; Savarino L; Verri E;
Gori A; Savioli F; Montanaro L
Bologna,Istituti Ortopedici Rizzoli
Extracts of six addition-type and six condensation-type
silicone dental impression materials were tested with L929
cells according to ISO 10993-Part 5 standard. The
cytotoxicity was evaluated by three different methods.
Contact between cells and material extracts was
maintained for 24 h in the first series of experiments but,
as in vivo application of these materials is restricted to a
few minutes, additional experiments were performed after
1 h of cell/extract contact. The addition-type silicones
were found to be non-toxic even when tested after
prolonged exposure of the cells to the materials while the
condensation-type polymers were cytotoxic at 24 h of
incubation. Most of the silicones were not toxic after 1 h.
16 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.706452
Item 144Nippon Gomu Kyokaishi
69, No.1, 1996, p.23-33
Japanese
AIR BAGS -FOR COMFORTABLE DRIVING INSAFETYSakurai T; Ozaki T; Ushio M
Toyo Gomu Kogyo KK
A discussion is presented of counter-measures taken to
prevent accidents under modern traffic conditions, and
of the development of air-bag systems and materials used
in them such as silicone rubber. 10 refs. Articles from
this journal can be requested for translation by subscribers
to the Rapra produced International Polymer Science and
Technology.
JAPAN
Accession no.705847
Item 145Nippon Gomu Kyokaishi
68, No.9, 1995, p.667-72
Japanese
SILICONE RUBBERSTakahashi M
Shin-etsu Chemical Industries Ltd.
Mechanical properties, abrasion characteristics,
application areas and patented methods for improving the
References and Abstracts
96 © Copyright 2001 Rapra Technology Limited
friction and abrasion characteristics of silicone rubbers
are discussed. 31 refs. Articles from this journal can be
requested for translation by subscribers to the Rapra
produced International Polymer Science and Technology.
JAPAN
Accession no.705426
Item 146Nippon Gomu Kyokaishi
68, No.7, 1995, p.453-59
Japanese
PROBLEMS OF ELASTOMERS USED INMEDICINEIkada Y
Kyoto,University
A classification of materials used in medical applications
is given according to their physical capacities, and current
problems relating to the use of polymer materials in
medicine are discussed, with particular reference to
silicone rubber, polyurethanes, natural rubber and
plasticised PVC. 10 refs. Articles from this journal can
be requested for translation by subscribers to the Rapra
produced International Polymer Science and Technology.
JAPAN
Accession no.704946
Item 147Patent Number: US 5779964 A 19980714
METHOD OF MAKING A MALE CATHETERWelch D P; Ryan T D; Knutson E M
Mentor Corp.
The catheter has a condom-like sheath of silicone rubber
sealingly engaging the penis of the patient. A catheter
stem at the distal end of the sheath couples to a urine
collection system. The sheath is sealed to the penis by an
adhesive, which is applied to the outer surface of the
sheath at the time of manufacture. A surface preparation
layer is applied over the adhesive. The sheath is rolled up
from the proximal end and unrolled to apply it to the
patient. During the unrolling process, the adhesive layer
is removed from the outer surface and deposited on the
inner surface of the sheath.
USA
Accession no.704566
Item 148Gummi Fasern Kunststoffe
48, No.4, 1995, p. 249-251
German
FLUOROSILICONE RUBBER - A VERYMODERN MATERIALKlages D; Raupbach U
Rado Gummi GmbH; GE Silicones
A brief historical survey is presented of the use of silicon
compounds, and some statistics are given on worldwide
silicone rubber production. The author discusses
processing of fluorosilicone rubbers and their properties,
including resistance to fuels, oils and solvents, heat
stability and good electrical properties. Articles from this
journal can be requested for translation by subscribers to
the Rapra produced International Polymer Science and
Technology.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.703558
Item 149Gummi Fasern Kunststoffe
48, No.4, April 1995, p.244-248
German
HOSES AND COUPLINGSHeitz E
Basic properties are given of materials used in the
manufacture of hoses and hose couplings - inner layers,
reinforcements and covers. The materials covered are
butyl rubber, chlorosulphonated polyethylene, ethylene-
propylene rubbers, natural rubber, acrylonitrile-butadiene
rubber, polychloroprene, polyether-urethane rubber and
silicone rubber. Articles from this journal can be requested
for translation by subscribers to the Rapra produced
International Polymer Science and Technology.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.703557
Item 150Industria della Gomma
41, No.8, Oct.1997, p.37-8
Italian
AUTOMATIC PRODUCTION UNIT FORRUBBER-METAL ARTICLESCoscia M
Rutil Srl
The production of an automotive gasket using machinery
developed by Rutil is described. The assembly consists
of a glass fibre-reinforced polyamide base over which is
moulded a silicone rubber gasket, and also incorporates
a number of metal reinforcement washers. The production
unit comprises a pair of C-frame injection presses, one
for moulding the base and the other for overmoulding
the gasket, with rotating tables for handling the parts, a
station for loading the metal washers into the mould, and
an industrial robot for checking the quality of the gaskets
before unloading.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.702481
Item 151Patent Number: US 5665809 A 19970909
References and Abstracts
© Copyright 2001Rapra Technology Limited 97
EXTRUDED SILICONE GEL PROFILESWojtowicz J
Raychem Corp.
A method is provided for making simple or complex
extruded gel profiles and the created article. In a
particularly preferred embodiment, the method involves
the extrusion of a silicone gel composition through a die
into a heated fluid to complete the cure of the gel as well
as to produce the desired gel profile shape. Shapes such
as stars, trapezoids, cusped squares, cusped triangle,
triangles and the like can be fabricated.
USA
Accession no.702431
Item 152International Polymer Science and Technology
25, No.4, 1998, p.T/81-4
MAMMARY PROSTHESES WITH APOLYURETHANE SHELLOsorgina I V; Begishev V P; Kondyurin A V; Plaksin S
A
Perm,State University; Russian Academy of Sciences;
Perm,Medical Academy
The shell was manufactured from segmented PU based
on an oligoether in the form of a copolymer of
polyoxypropylene glycol and polytetrahydrofuran and
2,4-toluene diisocyanate. Curing was carried out with 3,3-dichloro-4,4-diaminodiphenylmethane (Diamet Kh). The
shell was filled with a low molecular weight silicone
rubber of the SKTN-Med type. 10 refs. Translation of
Plast.Massy, No.8, 1997, p.26
RUSSIA
Accession no.702190
Item 153International Composites Expo ’98. Conference
proceedings.
Nashville,Tn., 19th-21st Jan.1998, Session 17-D. 627
ENHANCEMENTS IN RUBBER TOOLING/COMPOSITE FABRICATIONThomas J E
Tecnico Corp.
(SPI,Composites Institute)
A rubber tooling/composite fabrication process, where
silicone rubber is utilised as part of the tool assembly, is
described. The entire assembly of metal tool, rubber tool
and composite material is contained by an outer mould.
When heated, the rubber exerts pressure great enough to
laminate composite parts. An autoclave or vacuum system
is not required. Equations govern the sizing and expansion
of the rubber and lead to theoretical pressures, which can
be regulated. Tecnico has refined this process by utilising
heat strips which are placed in critical locations in the
mould. Conductive heating (vs. convection) allows faster
cure cycles than conventional methods. By the addition
or removal of heat strips, cold and hot spots in the mould
are eliminated, which is crucial for control of the rubber
pressure. The heating system also permits the composite
to be cured in virtually any location, as long as there is
electrical power. The process can be further improved by
better heating methods and improved silicone rubbers that
have higher operating temperatures, and could be recycled
into the next rubber casting. Other improvements could
be in the use of cooling systems allowing the mould
assembly to return to ambient temperature in a minimal
amount of time. 3 refs.
USA
Accession no.702051
Item 154154th ACS Rubber Division Meeting - Fall 1998.
Conference preprints.
Nashville, Tn., 29th Sept.-2nd Oct.1998, paper 12. 012
FASTER CURING LOW COMPRESSION SET NOPOST CURE LIQUID SILICONE RUBBERJohnson E
Wacker Silicones Corp.
(ACS,Rubber Div.)
The economies of the latest developments in liquid
silicone rubber (LSR) materials and process technology
make feasible the replacement of not only conventional
heat cured silicone rubber, but also organic rubber in many
applications. It is now possible to produce parts of at least
5 g in tools with over 30 cavities, with a production cycle
of as little as 20 seconds. The latest cold runner tool and
moulding press technology make it possible to produce
parts with no waste and no flash. This same technology
also makes possible continuous, fully automated
production. Parts can be ejected from the mould into a
box, ready for shipment with no need for deflashing. The
combination of these factors is, in many cases, rapidly
making older methods of moulded rubber part production
uneconomical, despite the premium cost of the LSR
material. Wacker has developed a unique and very
effective method of preventing after cure that has been
applied to a wide range of LSR products. The new
generation of LSR will enable the production of parts that
can behave like parts made from peroxide cure silicone
rubber, but will be able to cure much faster. They are
moulded in this fast, efficient operation without the need
of any subsequent processing.
USA
Accession no.701851
Item 155Journal of Macromolecular Science C
38, No.4, 1998, p.637-50
REVIEW OF ELECTROSYNTHESIS OFPOLYSILANESubramanian K
Vikram Sarabhai Space Centre
References and Abstracts
98 © Copyright 2001 Rapra Technology Limited
A review of the literature on the electrosynthesis of
polysilane is presented. The general procedure and
monomer systems for electroreductive polymerisation are
described, the mechanism of polysilane formation is
considered and the reductive polymerisation of halosilanes
in the presence of vinyl monomers is discussed. The review
clearly demonstrates that, by a suitable choice of solvent,
supporting electrolyte, dihalosilanes and complexing agent,
the electroreductive formation of Si-Si and C-Si linkages
can be used to synthesise ceramic-grade polysilane and
polycarbosilanes, respectively, with less than 0.1 wt %
oxygen and 20-75% yield of polymer. 45 refs.
INDIA
Accession no.700969
Item 156Rubber and Plastics News
28, No.3, 7th Sept.1998, p.6
LATEX-FREE CATHETER UNVEILED BYROCHESTERMcNulty M
Rochester Medical has launched a latex-free silicone
infection control catheter it believes will have a major impact
on both the acute care industry and the company’s bottom
line. The firm, which soon hopes to ready another innovative
product for the market, has also named a new marketing
and sales director. The maker of latex-free disposable urinary
continence care products introduced Release-NF in May and
June. The product has been in the testing and development
stages for several years. Introduction of the product ‘is the
most extensive marketing initiative the company has
undertaken to date’. It is a silicone-advanced Foley catheter
that delivers a controlled release of the antibacterial agent
nitrofurazone, which is contained in the silicone matrix inside
and outside the catheter. It is aimed at the acute care market
and is the first and only latex-free Foley that works as a drug
delivery system. Details are given.
ROCHESTER MEDICAL CO.USA
Accession no.699940
Item 157Kunststoffe Synthetics
No.9, 1994, p.8-11
German
WHERE HIGH TEMPERATURES AREINVOLVED, RELIANCE IS PLACED ONSILICONESFink P
Wacker Chemie GmbH
The use of liquid silicone rubber for injection moulding
is described as an alternative to the solid material or
other materials.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.699741
Item 158Machine Design
70, No.17, 24th Sept.1998, p.166/8
SILICONE-RUBBER HEATERS STRETCHPRODUCT UTILITYCobb P
Watlow Electric Mfg.Co.,Flexible Products Div.
Novel applications for silicone rubber heaters are reported,
and the versatility of the products are illustrated. Silicone
rubber heaters can be shaped to fit most new products,
and although many existing products can be modified,
the best fit is achieved from working with heater
specialists at the start of new design programs, it is
suggested. The construction of a heater is described,
together with and applications in heating frozen blood
for transfusions, in marine applications, and heating a
silicon wafer on a hot chuck for vacuum vapour
deposition.
USA
Accession no.699576
Item 159Plast’ 21
No.63, Sept.1997, p.34
Spanish
EXTENDED USE OF SILICONES IN THE CAR
A review is presented of automotive applications ofBayer’s Silopren range of liquid and solid silicone rubbers.
BAYER AGEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.698945
Item 160Rubber World
218, No.6, Sept.1998, p.20/69
PROCESSING GUIDE TO SILICONE RUBBEREXTRUSIONSTaylor T C
Specialty Silicone Products Inc.
This article is the second part of a series providing a
processing guide to silicone rubber extrusions. Screen
packs and breaker plate, feeding, screw designs, screw
flight design, and dies and guiders are discussed. A
troubleshooting chart is presented.
USA
Accession no.698783
Item 161Journal of Coated Fabrics
27, April 1998, p.326-37
NEW GENERATION OF SILICONEELASTOMERS FOR AIRBAG COATINGSBohin F; Pouchelon A; Surprenant R
Rhone-Poulenc Silicones
References and Abstracts
© Copyright 2001Rapra Technology Limited 99
In 1996, a new generation of silicone elastomers for
coating was launched on the European market.
Specifically designed to meet the airbag market, these
new products have specific rheological properties
allowing very thin coatings without any change in the
technology or use of a solvent, giving significant cost
reduction for the customer. Giving improved thermal
protection to the fabric, they are very well adapted to the
new generation of airbag inflators arising from the market.
Their specific properties also provide a 100% increase of
the fabric tear strength. 6 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.697986
Item 162Patent Number: US 5767183 A 19980616
HEAT SHRINKABLE SILICONE TUBE ANDMETHOD FOR MAKINGTakei H; Shimamoto N; Ohtsuka Y
Shin-Etsu Chemical Co.Ltd.
This tube is made from a silicone rubber composition
comprising a diorganopolysiloxane, a thermoplastic resin,
finely divided silica, an inorganic filler of titanium white,
alumina, quartz powder or talc having a mean particle
size of 0.5 to 15 micrometers and a curing agent by
extrusion moulding, preferably at a drawdown of 150 to
250%, vulcanisation and heat stretching in a radial
direction. It exhibits axial orientation during stretching
and shrinking subsequent thereto and is thus tearable.
JAPAN
Accession no.697587
Item 163RubberTech China ’98. Conference proceedings..
Shanghai, China, 24th-26th March, 1998, paper 17. 012
PROPERTIES AND APPLICATION OFSILICONE RUBBERS (HCR AND LR)Beisswenger H
Wacker Chemie GmbH
(Rapra Technology Ltd.; Crain Communications Ltd.)
The properties, applications, curing and processing of
silicone rubbers are discussed, with particular reference
to the differences between HCR (millable type) and LR
(liquid rubber). The comparisons between the two types
of rubber illustrate advantages and limitations for using
liquid silicone rubbers. Applications in automotive,
personal care products, keypads, baby teats and catheters
are described.
CHINA; EUROPEAN COMMUNITY; EUROPEAN UNION;
GERMANY; WESTERN EUROPE
Accession no.696400
Item 164Patent Number: US 5735985 A 19980407
METHOD FOR MICROMOULDING CERAMICSTRUCTURESGhosh S K; Furlani E P; Grande W J
Eastman Kodak Co.
Ceramic articles and structures having spatial features as
small as 0.1 micrometer and having a depth ranging from
2.0 to 100 micrometer are micromoulded using a master
mould of the article or structure to be moulded and
fabricated utilising a silicon wafer and dry etching
technology. A negative master mould is then produced
by placing the silicon master mould device in a
surrounding mould form and filling the mould form with
a silicone or silicone rubber, preferably a RTV silicone
rubber. Such material replicates each of the micro features
of the master mould in great detail to a resolution of the
order of 0.1 micrometer. The negative master mould is
then used in a die to mould the desired individual elements
or structures from a ceramic powder, which is capable of
replicating each of the micro features of the negative
master mould to the desired resolution.
USA
Accession no.695131
Item 165Patent Number: US 5656690 A 19970812
ORGANOPOLYSILOXANE COMPOSITIONSWHICH CROSSLINK TO GIVE ELECTRICALLYCONDUCTIVE ELASTOMERSPradl F; Fink P; Noemmer K; Birneder R
Wacker-Chemie GmbH
The invention relates to organopolysiloxane compositions
that when crosslinked form electroconductive elastomers.
The elastomers are formed via an addition crosslinking
method and contain 11-30 wt % with respect to the total
composition of carbon fibres having 0.1-10 mm average
length. The compositions are suitable for producing
injection moulded articles.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.690309
Item 166Rubber and Plastics News
27, No.23, 15th June 1998, p.28
DOW CORNING FORMULAS AID TWO HOSEMAKERSWilson E
Two companies are finding Dow Corning STI’s new
advances in silicone technology key ammunition in their
fight against coolant hose wear and tear. Flexfab Horizons
International and Thermopol are finding success in
utilising Dow Corning custom silicone formulations that
markedly sustain elastomeric hose endurance under
repeated exposure to rigorous pressure and temperatures.
Using the formulations, Flexfab has reported an increase
References and Abstracts
100 © Copyright 2001 Rapra Technology Limited
of 50% in the life of its heater and radiator hoses for Class
8 trucks. The firm now offers a warranty on its hoses for
up to 1.5 million miles. As under-the-hood temperatures
rise, cooling system hoses expand, increasing pressure
exerted upon them by metal stems to which they are
clamped. After cool-down, hose stems thin, caused by
this pressure, resulting in a gradual loss of sealant integrity
over extended periods of use. This loss is known as cold
leak. While the compression set of EPDM has been
measured by Society of Automotive Engineers coolant
hose specifications at 75-85%, and that of generic silicone
at 40%, the elastomeric bulk loss of Dow’s custom
formulated compound is 25%. Details are given.
DOW CORNING STI; FLEXFAB HORIZONS
INTERNATIONAL; THERMOPOL INC.USA
Accession no.689777
Item 167Journal of Biomaterials Applications
13, No.1, July 1998, p.66-73
PROPERTIES OF MAXILLOFACIAL SILICONEELASTOMERS REINFORCED WITH SILICAPOWDERAndreopoulos A G; Evangelatou M; Tarantili P A
Athens,National Technical University
Compounds of a silicone elastomer reinforced with
various amounts of silica powder, which were suitable
for preparing maxillofacial prostheses, were studied for
their mechanical response and wetting properties in terms
of contact angle. TS and EB showed an increase with
increasing silica volume fraction up to 35%, whereas the
Young’s modulus displayed a slight dependence on the
silica content and the resistance to tear increased
continuously with filler volume fraction (Vf). The wetting
properties, assessed via the contact angle, seemed to
degrade with increasing Vf, but a dependence on the
elastomer network density was also recorded. 10 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GREECE;
WESTERN EUROPE
Accession no.688759
Item 168Journal of Coated Fabrics
Vol.27, Jan.1998, p.219-36
PRECISION PLACEMENT OF THINPOLYMERIC SILICONE FILMS WITHINFABRICSMeirowitz R
Nextec Applications Inc.
Nextec patented technology is described which allows
for the precision placement of thin polymeric films around
fibres, crossover points and filling in or leaving open
interstitial spaces within fabrics. The choice of polymer,
substrate and placement of polymer is shown to allow
for improvement of properties, such as breathable barrier
performance, controlled porosity, resistance to fluids and
adhesion/release behaviour. Applications of the
technology in apparel, automotive, aerospace and medical
fields are described. The benefits in these applications
are delivered in a process that has no volatile organic
compounds and yields inert residual materials. Examples
of materials and comparative performances are discussed.
7 refs.
USA
Accession no.688755
Item 169Kautchuk und Gummi Kunststoffe
51, No.6, June 1998, p.410/5
German
LIQUID SILICONE RUBBER - PROPERTIESAND APPLICATIONSJerschow P
Liquid silicone rubber is used to produce elastic parts by
injection moulding. Its main properties range from high
resistance against temperatures (both high and low
temperatures) and chemicals to high transparency and
good mechanical properties. It is used in automotive parts,
electronics, medical devices, food and household
appliances and many other sectors. Liquid silicone rubber
is processed fully automatically in an injection moulding
machine. The applications, processing and properties of
liquid rubber are summarised. 5 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.687926
Item 170Patent Number: US 5693689 A 19971202
MONITOR PUTTY WITH INCREASINGSTIFFNESSGibbon R M
JMK International Inc.
An exercise putty kit providing manipulative physical
therapy of increasing difficulty comprises a container
of a large mass of borosiloxane putty and a package of
borosiloxane or siloxane putty. At least one small mass
is provided to the patient along with the large mass, the
small mass and large mass being manipulated by the
patient until a uniform colour and stiffness are achieved
in the combined mass. Preferably, a plurality of small
masses having a variety of colours are available for
successive manipulation with the combined mass. The
kit provides a means by which the difficulty of
manipulative physical therapy may be monitored and
increased. As more small masses are added to the
combined mass, the stiffness increases, requiring more
manipulation to fully blend the masses.
USA
Accession no.687072
References and Abstracts
© Copyright 2001Rapra Technology Limited 101
Item 171International Polymer Science and Technology
24, No.12, 1997, p.T/9-13
NEW TECHNIQUES IN EXTRUSION ANDVULCANISATIONColombo U
Brief details are given of new extrusion and vulcanisation
systems and techniques. Some data are given for the
extrusion of hoses and sections made from silicone rubber
and extrusion lines for the manufacture of elbow hose
blanks. Translated from Gummi Fas Kunst, No.10, 1997,
p.804
Accession no.684804
Item 172Journal of Biomedical Materials Research (Applied
Biomaterials)
43, No.2, Summer 1998, p.99-107
BIOCOMPATIBILITY RESPONSE TOMODIFIED BAERVELDT GLAUCOMA DRAINSJacob J T; Burgoyne C F; McKinnon S J; Tanji T M;
LaFleur P K; Duzman E
Louisiana,State University
Details are given of the modification of a Baerveldt
glaucoma filtering device made of silicone rubber by
adding porous cellular ingrowth material to the posterior
surface of the drainage plate. These materials were
implanted and their biocompatibility was investigated. 33
refs.
USA
Accession no.682945
Item 173Macplas International
Feb.1998, p.42-3
LIQUID RUBBER
MIR has perfected its injection moulding machines
devoted to liquid silicone rubber, achieving the production
of very small to medium size parts of excellent quality at
competitive prices. LSR has high electrical insulation
properties, high resistance to extremes of temperature,
long life, and is non-toxic, non-allergenic and
biocompatible. LSR brings benefits from advanced
processing technology. Manufacturers can obtain
consistent material savings in terms of scrap, flash and
runners.
MIR SPAEUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.682023
Item 174Biomaterials
19, Nos 1-3, 1998, p.55-60
ANALYSIS OF MRI IMAGES OF A SILICONE
ELASTOMER UNDER DIFFERENT AXIALLOADING CONDITIONSAbel E W; Wheeler K I; Chudek J A; Hunter G; Som F M
Dundee,University
Results are presented of tests on axially tensioned silicone
elastomer tendon spacer samples to determine the
relationship between stress in the material and image
intensity. Images were obtained using spin echo, gradient
echo and magnetic resonance imaging snapshot
techniques. 15 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.681411
Item 175Advanced Materials & Processes
153, No.5, May 1998, p.6
VERY SPECIAL CARS BOAST SPIN-CASTPARTS
Metalcrafters builds one-of-a-kind automobile prototypes.
The company was helped by Chrysler to get its business
off the ground with a request for road-worthy metal-
bodied prototypes. In a bid to find a faster way to produce
low to medium volumes of smaller parts like emblems,
air vents, door handles and dashboard knobs,
Metalcrafters turned to spin casting. Silicone rubber
moulds can produce up to 1500 parts, the company claims.
METALCRAFTERSUSA
Accession no.680676
Item 176Rubber and Plastics News
27, No.19, 20th April 1998, p.6
AMERICAN BIOMED CATHETER GAINSCLEARANCEMcCann J
American BioMed Inc. is reported to have gained
clearance from the FDA for a new silicone rubber
thrombectomy catheter that removes blood clots from
blood vessels. A description is given of the Ahn catheter,
which is expected to be launched in this year’s second
quarter, and a US patent on the device is expected during
the next two months. Its design consists of a three balloon
type, which is said to give surgeons more inflation control
during operations and helps prevent blood spattering when
it’s removed. It is the company’s first internally developed
product to make it through the FDA process on a fully
independent basis, it is reported.
AMERICAN BIOMED INC.USA
Accession no.680170
Item 177Journal of Macromolecular Science C
References and Abstracts
102 © Copyright 2001 Rapra Technology Limited
C38, No.2, 1998, p.143-205
SOME HETEROCYCLIC POLYMERS ANDPOLYSILOXANESLu F
Academia Sinica
A review is given of research into several important
heterocyclic polymers with emphasis given to
polyphenylquinoxalines, polytriazines, polypyrrolones,
polyimides, polyamide-imides, polybenzimidazoles, and
polysiloxanes. Details are given of the synthesis of new
monomers and polymers and the development of new
synthetic routes. The thermal degradation, pyrolysis and
hydrolysis at high temperature are discussed. 162 refs.
CHINA
Accession no.679421
Item 178Journal of Polymer Science : Polymer Physics Edition
36, No.6, 30th April 1998, p.1091-4
ELECTRORHEOLOGICAL FLUID ANDSILOXANE GEL BASEDELECTROMECHANICAL ACTUATOR:WORKING TOWARD AN ARTIFICIAL MUSCLEBohon K; Krause S
Rensselaer Polytechnic Institute
A device has been developed to simulate muscle operation
with the time response of the order of a striated skeletalmuscle. 8 refs.
USA
Accession no.678661
Item 179Modern Plastics International
28, No.4, April 1998, p.64-5
NEW FORMULATIONS, PROCESSTECHNOLOGY PROPEL SILICONEMOULDINGSmock D
Recent advances in polymer formulations and process
technology are propelling a boom in liquid silicone
moulding. It is claimed that companies can attain
significant reductions in total part costs with liquid
injection moulding compared with processing heat-cured
elastomers. One development at GE Silicones is low-
compression-set formulations that open opportunities in
automotive applications for moulders seeking ways to add
value to existing business.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
USA; WESTERN EUROPE
Accession no.678253
Item 180Injection Molding
6, No.2, Feb.1998, p.53
USING LIM TO CREATE BETTER, FASTER,
CHEAPER PROTOTYPES
This article highlights an injection moulding process that
has been developed by Vesta Inc. of the USA, intended
to put an end to lengthy, expensive prototype production
of medical products. “Quick Response” uses liquid
injection moulding (LIM) equipment to mould medical-
grade liquid silicone rubber in low volumes.
VESTA INC.USA
Accession no.677267
Item 181Kunststoffe Plast Europe
87, No.10, Oct.1997, p.46-8
English; German
LIQUID SILICONE RUBBERPohmer K; Schmidt G; Steinberger H; BruendL T;
Schmidt T
In this paper, liquid silicone rubber is placed under the
spotlight, and its properties, processing methods (liquid
injection moulding, multi-component injection moulding,
as well as modifying and finishing), and typical
applications are all considered.
EUROPE-GENERAL; EUROPEAN COMMUNITY; EUROPEAN
UNION; GERMANY; WESTERN EUROPE; WORLD
Accession no.676699
Item 182Patent Number: EP 832936 A1 19980401
PHOTOCURABLE LIQUID SILICONE RUBBERCOMPOSITIONS FOR TEMPLATING MOTHERMOULDSFujiki H; Sakamoto T
Shin-Etsu Chemical Co.Ltd.
The cured products have a Shore hardness of 20 to 60
and a light transmittance of at least 10% at a wall gauge
of 10 mm. A photocurable liquid resin cast into the mould
is cured with light transmitted by the mould wall.
JAPAN
Accession no.675916
Item 183Macromolecular Symposia
No.127, Feb.1998, p.205-9
COMPOSITE MATERIAL FOR MEDICALAPPLICATIONZamyslov E V; Klochkov V I; Ostrovidova G U
St.Petersburg,Institute of Technology
Details are presented of the preparation of graphite filled
PDMS for medical applications. The physico-chemical
and mechanical properties were determined. Predicted
thromboresistance is discussed. 22 refs.
RUSSIA
Accession no.672899
References and Abstracts
© Copyright 2001Rapra Technology Limited 103
Item 184Journal of Microencapsulation
15, No.2, March-April 1998, p.227-36
PREPARATION OF SILICONE MICROSPHERESBY EMULSION POLYMERIZATION:APPLICATION TO THE ENCAPSULATION OF AHYDROPHILIC DRUGKedzierewicz F; Darme X; Etienne A; Lemut J;
Hoffman M; Maincent P
Nancy I,University; Dow Corning
The ability of suitable silicone elastomers to encapsulate
hydrophilic compounds in microspheres prepared
according to a multiphase emulsion-polymerisation
process was evaluated. The particle size of the
microspheres could be modified by controlling the usual
emulsification parameters, such as the viscosity of the
different phases, shear rates and surface activity properties
of additives. The encapsulation efficiencies of a
hydrophilic drug, propranolol hydrochloride, were very
high but its release rates were very slow. Osmotic agents
such as glycerol and propylene glycol did not enhance
the release rate, whereas it was slightly increased by both
sodium chloride addition and higher drug loading. 11 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.671085
Item 185Plastiques Modernes et Elastomeres
48, No.7, Sept.1996, p.38/41
French
SILICONE RUBBERS: PROCESSING,PROPERTIES AND APPLICATIONSVasselle J B
The processing, vulcanisation, properties and applications
of hot curing and liquid silicone rubbers are reviewed,
and applications of liquid silicone rubbers in injection
and insert moulding are examined. Statistics are presented
for world consumption of silicone rubbers.
BAYER AG; GE PLASTICSEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
USA; WESTERN EUROPE; WORLD
Accession no.670761
Item 186Journal of Biomedical Materials Research (Applied
Biomaterials)
43, No.1, Spring 1998, p.1-14
INFLUENCE OF PDMS SURFACE TEXTURE ONHUMAN SKIN FIBROBLAST PROLIFERATIONAS DETERMINED BY CELL CYCLE ANALYSISvan Kooten T G; Whitesides J F; von Recum A F
Clemson,University
The interaction of human fibroblasts with silicone
surfaces was studied using cell cycle analysis. The
potential of cell cycle analysis to serve as an integrated
tool in models for biocompatibility assessment in vitro
is discussed. 27 refs.
USA
Accession no.670595
Item 187Surface Coatings International
81, No.2, Feb.1998, p.89-93
MASONRY PROTECTION WITH SILANES,SILOXANES AND SILICONE RESINSMayer H
Wacker-Chemie GmbH
The use is discussed of silanes, siloxanes and silicone
resins in the masonry protection field, where they act
as binders in decorative coatings or as water-proofing
agents. An overview is presented of applications,
product classes and other modes of action. Applications
considered include silicones in masonry paints and
plasters, where they work as binders, additives or
primers, in construction chemicals, where they work
as water and oil repellents, damp-proofing agents or
stone strengtheners, in in-plant produced materials such
as roof tiles and gypsum boards, where they work as
water repellents for after-treatment applications or for
core-treatment applications. The suitability of a single
product class of these silicone masonry water repellents
based on silanes, siloxanes and silicone resins are
discussed for the above applications.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.669231
Item 188Journal of Biomaterials Applications
12, No.3, Jan.1998, p.258-71
BIOMEDICAL SILICONE ELASTOMERS ASCARRIERS FOR CONTROLLED RELEASEAndreopoulos A G; Plytaria M
Athens,National Technical University
The potential of biomedical siloxane elastomers as
carriers for controlled release of drugs was assessed.
A two-component silicone gel system was used and
various crosslinking agent ratio was applied in order
to produce networks with varying crosslink density.
Swelling experiments in toluene were conducted in
order to evaluate the network characteristics. The
silicone elastomer was loaded with salicylic acid and
propanolol hydrochloride and their delivery in distilled
water was followed. The results showed that release
was almost of zero order for high loading of salicylic
acid, while delivery seemed to be diffusion-controlled
up to a certain limit. The drug concentrations
administered were relatively low if silicone discs were
used, due to the hydrophobic nature of this material.
When membranes with a thickness of 0.1-0.2 mm were
used, on the other hand, the delivery rate was much
References and Abstracts
104 © Copyright 2001 Rapra Technology Limited
higher depending, of course, on the hydrophilic
character of the drug. 18 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GREECE;
WESTERN EUROPE
Accession no.668285
Item 189Rubber World
217, No.3, Dec.1997, p.42-4
SILICONE POLYMERS FOR HIGH-VOLTAGEINSULATORSOwen M J
Dow Corning Corp.
Composite insulators with sheds moulded from silicone
rubber have been used in high-voltage service for nearly
30 years and their popularity is on the rise. Silicone
compounds retain hydrophobicity better than ceramics
or glass, especially in coastal regions and contaminated
areas. Composite insulators are lightweight and can
significantly reduce losses from breakage and vandalism.
Much of the current work on the newest generation of
silicone insulators focuses on surface chemistry to better
understand the effects of long-term ageing and electrical
discharge. 9 refs.
USA
Accession no.668231
Item 190Patent Number: US 5639416 A 19970617
METHOD OF MOULDING PRECISION PARTSPennisi R W; Jackson G D; Urbish G F; Megleo L D
Motorola Inc.
This low pressure injection moulding method uses a two-
piece silicone rubber mould having a cavity representative
of the shape of the article to be moulded. The mould is
substantially encased on all sides in a rigid mould box to
prevent deformation of the cavity during the moulding
process. The mould box and the encased mould are placed
in a vacuum chamber and a vacuum is drawn on the
chamber to evacuate the cavity. A predetermined amount
of a reactive mixture is simultaneously mixed and injected
under pressure into the mould to form the article. The
amount of material injected is sufficient to fill the cavity
but not sufficient to distort the cavity. The chamber is
vented and the mould is removed from the mould box.
The mould is then flexed to remove the article therefrom.
USA
Accession no.667840
Item 191Patent Number: EP 816436 A1 19980107
ROOM TEMPERATURE CURABLEORGANOPOLYSILOXANE COMPOSITIONKimura T; Suzuki K; Teshigawara M
Shin-Etsu Chemical Co.Ltd.
This includes a diorganopolysiloxane terminated with a
hydroxyl group at both terminal ends and having a
viscosity at 25C of 25 to 1,000,000 cSt, an organosilane
having 3 or more hydrolysable groups (ketoxime or
alkenyloxy groups) per molecule, a partially hydrolysed
and condensed product thereof or a mixture thereof and a
thin leaf-like inorganic filler. Cured products based
thereon have good oil resistance and are suitable as FIPG
materials for automobiles.
JAPAN
Accession no.665650
Item 192Rubber and Plastics News
27, No.3, 8th Sept.1997, p.11
NOT DUMB LUCKCampanelli J
This article relates the story of how Kathryn Krotseng
created a patented silicone moulding process (the
inversion moulding system or IMS) to make mannequins.
Silicone mannequins, as opposed to PU dummies, are non-
corrosive, non-toxic, and non-flammable. The IMS
process is described.
MANNI-KIT INC.USA
Accession no.665007
Item 193Plastiques Flash
No.287, Jan./Feb.1996, p.70-1
French
STATE OF THE ART IN MOULDING LIQUIDSILICONES
The Arburg Allrounder 120 V-40 injection moulding
machine and its use in the manufacture of prototype
automotive components from liquid silicone rubbers are
described.
ARBURG MASCHINENFABRIK; WOCO; EOC
NORMALIENEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.663471
Item 194Revista de Plasticos Modernos
70, No.472, Oct.1995, p.379-81
Spanish
MCP VACUUM CASTING SYSTEMMCP Iberia SA
Details are given of the MCP vacuum casting system for
the production of plastics prototypes using silicone rubber
moulds.
EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN;
WESTERN EUROPE
Accession no.663464
References and Abstracts
© Copyright 2001Rapra Technology Limited 105
Item 195Analytical Chemistry
69, No.23, 1st Dec.1997. p.4912-6
RELEASE OF LOW MOLECULAR WEIGHTSILICONES AND PLATINUM FROM SILICONEBREAST IMPLANTSLykissa E D; Kala S V; Hurley J B; Lebovitz R M
Baylor College of Medicine
A series of studies was conducted addressing the chemical
composition of silicone gels from breast implants as well
as the diffusion of low molecular weight silicones and heavy
metals from intact implants into various surrounding media,
namely lipid-rich media (soy bean), aqueous tissue culture
medium (modified Dulbecco’s medium, DMEM), or an
emulsion consisting of DMEM plus 10% soy oil. The rates
at which LM-silicones and platinum leaked through the
intact implant outer shell into the surrounding media under
a variety of conditions were studied. 14 refs.
USA
Accession no.662917
Item 196Rubber and Plastics News
27, No.8, 17th Nov. 1997, p.10
NEW COMPANY LAUNCHES NON-METALHEAD GASKETMeyer B
A high temperature, non-metallic head gasket has been
developed that is competitive with metal gaskets.
Developed by William A. Clarke, a former Ford Motor
engineer, it consists of silicone rubber, which he describes
as a pre-ceramic polymer, and a key part of the material
is said to be the fibre reinforcement from Owens Corning
which is claimed to have unusually low thermal
expansion. Clarke’s company is called Gasket King: A
Briefer Clark Company L.L.C., and is currently operating
by using excess capacity at Edler Industries’ plant under
a government program to fund the development of
peacetime products at factories primarily geared toward
defence work.
GASKET KING: A BRIEFER CLARK CO.LLC;
DELER INDUSTRIESUSA
Accession no.662690
Item 197Medtec. Conference proceedings.
Amsterdam, 21st-23rd Oct.1997, Session 102, Thomas,
p.1-6. 6S
BIOPERFORMANCE OF SILICONEMATERIALS IN BIOMEDICAL APPLICATIONSThomas X; Briquet F
Dow Corning Corp.
(Canon Communications Inc.)
The use of polymers for biomedical applications has been
dramatically expanding during the last decades. As
biomaterials, they now play an essential role in helping
healthcare workers to save life, alleviate pains and improve
the general quality of life. Several guidelines and test methods
ensure that adequate information exists regarding the function
of the device and its toxicity profile to define its risk to benefit
ratio. However, beyond the legal requirement, which allows
to qualify biocompatible materials against industrial ones,
there is still an opportunity for performance improvement
in specific applications and thus the differentiation of some
biomaterials to offer substantial benefits. The concept of
BioPerformance is introduced and illustrated with three
comparative examples which highlight the unique
contribution of recognised silicone products to selected
biomedical applications. 13 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.662523
Item 198Journal of Biomedical Materials Research
37, No.4, 15th Dec.1997, p.539-47
EFFECT OF SUBCUTANEOUS SILICONERUBBER IMPLANT WITH SHALLOW SURFACEMICROGROOVES ON SURROUNDING TISSUESIN RABBITSden Braber E T; de Ruijter J E; Jansen J A
Nijmegen,University
It has been suggested that during wound healing,
microtextured surfaces can alter events at the interface
between implant surface surface and surrounding tissues.
To investigate this phenomenon, smooth and microtextured
silicone rubber implants are implanted subcutaneously in
rabbits for 3, 7, 42 and 84 days. The textured implants possess
parallel surface microgrooves and ridges with a width of
2.0, 5.0 and 10.0 micrometer. All grooves have a depth of
approximately 0.5 micrometer. SEM observation shows
fibroblasts, erythrocytes, lymphocytes, macrophages, fibrin
and collagen on all implant surfaces after three and seven
days. After 42 and 84 days only little collagen, a small number
of fibroblasts, but no inflammatory cells are seen on the
implant surfaces. The fibroblasts are not oriented along the
surface grooves on all textured surfaces. Three-dimensional
reconstruction of CLSM images and LM images show no
significant differences between the thickness of the capsules
surrounding the smooth and those surrounding the
microgrooved implants. In contrast, LM does show a
significantly lower number of inflammatory cells and a
significantly higher number of blood vessels in the capsules
surrounding the microgrooved implants. Differences
between the 2.0, 5.0, and 10.0 (m grooved implants are not
detected. Results concerning capsule thickness suggest that
the depth of the grooves is not sufficient to facilitate
mechanical interlocking, but the cause for the observed
differences in inflammatory response and number of blood
vessels remains unclear. 29 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.662315
References and Abstracts
106 © Copyright 2001 Rapra Technology Limited
Item 199Journal of Biomedical Materials Research
37, No.4, 15th Dec.1997, p.534-8
ADJUVANCY EFFECT OF DIFFERENT TYPESOF SILICONE GELNaim J O; Ippolito K M L; van Oss C J
Rochester,General Hospital; Buffalo,University
Women with silicone gel-filled breast implants (SBIs) are
likely to be at a slightly higher risk of developing an
autoimmune-like syndrome. This risk, although small,
may be associated with the immunological adjuvancy
property of the silicone gel. However, not all silicone gels
are chemically formulated exactly the same and their
adjuvancy behaviour may vary. This e adjuvant effect of
three different lots of silicone gel is compared in rats,
using ovalbumin (OVA) as the test antigen. Test bleeds
are taken at 21, 48, 62 and 84 days post immunisation
and the rat sera are analysed for anti-OVA antibodies by
enzyme-linked immunosorbent assay (ELISA). A delayed
type hypersensitivity (DTH) test is performed on all the
treated rats beginning at 14 post-immunisation days. The
results show that silicone gel No.3 (McChan lot no.
S0400488) produces the highest mean anti-OVA antibody
titre followed by silicone gel No.1 (DC lot No.
HHO19581) and silicone gel No.2 (McChan lot No.
13P9339). The DTH results show that rats treated with
silicone gel 1 and 3 have a clear positive response, whereas
silicone gel 2 causes only a minimal response. These
results demonstrate the immunological adjuvancy
difference among three types of silicone gel. The chemical
composition of each of these silicone gels, that would
help explain these results, is yet to be determined. 12 refs.
USA
Accession no.662314
Item 200152nd ACS Rubber Division Meeting, Fall 1997.
Conference Preprints.
Cleveland, Oh., 21st-24th Oct.1997, Paper 96, pp.32.
012
BASIC STUDY OF CONTINUOUS ULTRASONICDEVULCANIZATION OF UNFILLED SILICONERUBBERDiao B; Isayev A I; Levin V Yu
Akron,University,Inst.of Polym.Engineering
(ACS,Rubber Div.)
Unfilled polydimethyl siloxane vulcanisates were
ultrasonically devulcanised under several processing
conditions in an extruder with an ultrasound die
attachment. Gel fraction and crosslink density
measurements indicated that the rubber was partially
devulcanised. The cure behaviour, rheological properties
and structural characteristics of the devulcanised and
virgin rubbers were studied, and the mechanical properties
of revulcanised samples were compared with those of the
virgin rubber. GPC results implied that the creation of a
branched structure in the network was possible after
devulcanisation. Revulcanisation of rubbers devulcanised
under optimal conditions gave mechanical properties
better than those of the virgin rubber. Blends of
devulcanised and virgin rubbers showed the same tensile
strength and modulus as the virgin rubber but higher
elongation. 16 refs.
USA
Accession no.659540
Item 201Patent Number: US 5616647 A 19970401
ONE PART ROOM TEMPERATUREVULCANISING COMPOSITION HAVING BOTHA HIGH RATE OF EXTRUSION AND LOW SAGDziark J J; Pink M R; Martucci J P
General Electric Co.
A base mixture of a diorganopolysiloxane and an end
stopping crosslinking ketoximosilane are reacted prior to
being added to a first injection port along an extruder. An
inorganic filler is added to the base mixture at a second
injection port along the extruder, an M stopped silicone
fluid is partitioned into two parts and the first part of the
M stopped fluid is added to the filler containing base
mixture at a third injection port at the middle of the
extruder. A tin catalyst, an adhesion promoter and the
second part of the M stopped fluid is added at a fourth
injection port along the extruder and the mixture is
extruded towards the extruder exit port.
USA
Accession no.658578
Item 202152nd ACS Rubber Division Meeting, Fall 1997.
Conference Preprints.
Cleveland, Oh., 21st-24th Oct.1997, Paper 30, pp.11.
012
LR3014 SERIES: A NEW FAMILY OF LIQUIDSILICONE RUBBER FOR OUTSTANDING, NOPOST CURE PERFORMANCE IN OIL SEALINGAPPLICATIONSJohnson T
Wacker Silicones Corp.
(ACS,Rubber Div.)
Applications of liquid silicone rubber (LSR) in injection
moulded automotive seals and gaskets are examined, and
results are presented of a study which was undertaken to
compare the performance of a conventional LSR
compound with that of a grade in the Elastosil LR3014
series (Wacker Silicones) which employs a method of
controlling aftercure without post curing. This new grade
showed advantages in terms of reduced compression set,
greater heat resistance, equivalent resistance to motor oils
and equivalent to substantially improved resistance to
different types of transmission fluids.
USA
Accession no.658284
References and Abstracts
© Copyright 2001Rapra Technology Limited 107
Item 203Biomedical Materials
Oct. 1997, p.10-11
SILICONE IMPLANTS
The use of silicone in testicular implants has declined
following the moratorium on the use of silicone breast
implants by the FDA, it is reported. Problems regarding
the presence of impurities in the silicone polymer such
as silica which was used to harden the elastomer, platinum
which acted as the catalyst, and a variety of organic and
inorganic compounds including talc have been implicated
in inciting an inflammatory response in the recipient
which is difficult to avoid, claim scientists. In addition,
the rarity of connective tissue diseases and the long latency
period mean that the definitive epidemiological study to
detect an association between silicone implants and
connective tissue disease, may never be performed, it is
argued.
USA
Accession no.655797
Item 204Kunststoffe Plast Europe
87, No.9, Sept. 1997, p.41-2
LIQUID SILICONE RUBBER (LSR) CAPSEmmerichs H; Giesler D
EOC Normalien
The injection moulding of liquid silicone rubber caps
using a 16 cavity mould with a cold runner system, is
described. The cap is for protecting the power door lock
switch in a car from moisture and dirt. It is stated that the
low viscosity of liquid silicone rubber requires special
precautions with respect to design and operations of
injection moulds, and the use of a standard cold runner
system is said to simplify processing. It is advised that
care should be taken to provide proper thermal separation
of the runner system from the part forming sections of
the mould, but that demoulding of parts with small
undercuts should not cause problems. Details are given
of the mould design and the runner system, and part
release/ejection.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.655713
Item 205Journal of Biomedical Materials Research
36, No.4, 15th Sept.1997, p.487-97
EFFECT OF SALINE EXPOSURE ON SURFACEAND BULK PROPERTIES OF MEDICAL GRADESILICONE ELASTOMERSKennan J J; Peters Y A; Swarthout D E; Owen M J;
Namkanisorn A; Chaudhury M K
Dow Corning Corp.; Lehigh University
Medical grade silicone elastomers are subjected to
accelerated ageing in saline to verify the hydrolytic
stability of the elastomer. Tensile strength, elongation at
break and elastomer stress measured at 100% or 200%
elongation do not change significantly for peroxide-cured
sheeting aged in 37 deg.C or 100 deg.C saline for 45 h.
Under similar conditions, hydrosilylation cured sheeting
behaves similarly; however, increases in stresses
measured at 100% and 200% elongation are observed after
the first hour of treatment. After the first hour, the physical
properties remained relatively constant. On either
elastomer, initial liquid drop advancing contact angles for
water ranges from 110-115 deg., and in no case is a change
of more than 6 deg. observed as a result of ageing in saline
for 45 h at temperatures up to 97 deg.C. The high
advancing angles indicated that the surface remains
largely hydrophobic. Initial liquid drop receding contact
angles range from 48-64 deg., with receding contact
angles being more sensitive to accelerated ageing, in one
case decreasing to 14 deg. Similar decreases in receding
contact angle are observed in PE subjected to the same
accelerated ageing conditions. Decreases in receding
contact angle are not considered to be indicative of
extensive hydrolysis. The observed contact angle
phenomena are consistent with current views of contact
angle hysteresis being caused by surface heterogeneity.
There is no evidence of significant surface or bulk siloxane
hydrolysis under these accelerated ageing conditions. 19
refs.
USA
Accession no.654416
Item 206Journal of Materials Science.Materials in Medicine
8, No.10, Oct.1997, p.631-5
CONDITIONING FLUID INFLUENCES ON THESURFACE PROPERTIES OF SILICONE AND PUPERITONEAL CATHETERS: IMPLICATIONSFOR INFECTIONGorman S P; Jones D S; Mawhinney W M; McGovern
J G; Adair C G
Belfast,Queen’s University
Details are given of the adherence of Staphylococcus
epidermidis to PU and silicone peritoneal catheters in the
presence and absence of proteinaceous conditioning film.
The effects of these conditioning films on the surface
properties of the biomaterials were investigated. Bacterial
adherence was examined using a radiometric adherence
assay. 25 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.653384
Item 207International Polymer Processing
12, No.2, July 1997, p.174-81
DETERMINATION OF INTER-RELATIONSHIPSBETWEEN PROCESSING CONDITIONS ANDPROPERTIES OF INJECTION MOULDED
References and Abstracts
108 © Copyright 2001 Rapra Technology Limited
SILICONE RING USING EXPERIMENTALDESIGNBarbaroux M; Stalet G; Regnier G; Trotignon J-P
Dow Corning France SA; Ecole Nationale Superieure
des Arts et Metiers
The effects of injection moulding parameters on the
mechanical-physical properties of a liquid silicone rubber
(LSR) injection moulded ring are studied through an
experimental design. The effects of the changeover point
(volume or pressure driven), runner (hot or cold), hold
pressure, mould temperature and injection flow rate
variations are evaluated based upon the responses related
to both material properties (ultimate elongation and tensile
stress in a tensile test, swelling in hexane, hardness,
density) and ring properties (cross sectional diameter,
weight, volume). It is determined that ring density is not
dependent on the parameters studied. The mould
temperature appears to be a very influential parameter,
especially concerning material characteristics: it affects
the swelling ratio, hardness, and ultimate properties, but
weight and volume are only affected when the cold runner
is used. The hold pressure has an effect on both the weight
and volume of the ring. The type of changeover used
(volume or pressure) has no effect when a cold runner is
used, but affects the weight, volume and ultimate
properties of the ring, when a hot runner is used. The
injection flow, rate does not affect the observed
characteristics. 20 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.652454
Item 208Biomedical Materials
July 1997, p.12
SILICONE IMPLANTS ARE AT CENTRE OFFRESH CONTROVERSY
This abstract describes the problems associated with
assessing the long-term risks of silicone implants. The
article includes information on the current controversy
over possible adverse health effects of silicone breast
implants and the carcinogenical potential associated with
lifetime tissue exposure to various forms of silicone
polymers.
US,FOOD & DRUG ADMINISTRATIONEUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA;
WESTERN EUROPE
Accession no.651091
Item 209Polymers for Advanced Technologies
8, No.7, July 1997, p.465-70
OXYGEN-CROSSLINKED POLYSILANE: NEWCLASS OF SI-RELATED MATERIAL FORELECTROLUMINESCENT DEVICESHiraoka T; Majima Y; Murai S; Nakano Y; Hayase S
Toshiba Corp.
The preparation and optical properties of the novel
silicone-related material, oxygen-crosslinked polysilane,
are investigated. The oxygen-crosslinked polysilane is
prepared by the thermal annealing of the precursor
polysilane bearing alkoxyl groups. The
photoluminescence, consisting of a broad visible band at
about 440 nm and a relatively sharp band at about 360
nm, is observed at room temperature. The relative
intensities of the visible emission are changed during
crosslinking. Visible emission is greatly affected by the
steric hindrance of the alkoxyl groups of the precursor.
Visible electroluminescene (EL) is also observed
uniformly from the EL cell consisting of the oxygen-
crosslinked polysilane film sandwiched between the Al
electrode and indium-tin oxide (ITO) electrode. The
current densities of the EL cell increase with an increase
in the oxygen-crosslinking. 15 refs.
JAPAN
Accession no.648094
Item 210Chemistry & Industry
No.13, 7th July 1997, p.498
NO EVIDENCE OF SILICONE IMPLANTHEALTH RISK
A new study from the American Academy of Neurology
has reported that there is no evidence to show that silicone
implants cause disease. The article supplies details of the
report’s findings, which could shatter the hopes of
thousands of women who are suing for damages over the
alleged link between implants and ill health.
AMERICAN ACADEMY OF NEUROLOGY; DOW
CHEMICAL CORP.; DOW CORNING CORP.USA
Accession no.647598
Item 211Patent Number: US 5589119 A 19961231
SILICONE ELASTOMER SEALS FORMOULDED PLASTIC PARTSHetherington R C
New Southland Inc.
A process is described for bonding a silicone elastomer
seal to a moulded plastic part, such as an electrical
connector. Prior to moulding, aromatic polyamide pellets
are pretreated with an aminofunctional silicone fluid and
the pretreated pellets are then moulded in the presence of
moisture at a temperature sufficient to chemically graft the
amino function of the silicone fluid to the aromatic carbonyl
function of the aromatic polyamide and to form silanol
groups within the aminofunctional silicone fluid. The
moulded part is coated with an organofunctional
alkoxysilane having at least one vinyl group and then heated
in the presence of moisture to convert the alkoxysilane into
a siloxane polymer with vinyl and silanol groups. These
silanol groups then react with the silanol groups of the
References and Abstracts
© Copyright 2001Rapra Technology Limited 109
aminofunctional silicone fluid. A liquid silicone elastomer,
which contains sufficient Si-H groups to react with vinyl
groups contained in the siloxane polymer formed from the
alkoxysilane, is applied to the coated moulded plastic part,
which is then heated to form a covalent bond between vinyl
groups of the siloxane polymer and Si-H groups of the
elastomer, the liquid silicone elastomer forming a seal,
which is bonded to the moulded plastic part.
USA
Accession no.647462
Item 212Molecular Crystals & Liquid Crystals
Vols 294 & 295, 1997, p.127-32
LIGHT-EMITTING DIODES BASED ONSILICON-BACKBONE POLYMERSSuzuki H
NTT
Electroluminescence characteristics were measured and
analysed as a function of temperature, electron injecting
electrodes, and the concentration of defects at the
polymethylphenylsilane-electron injecting electrode
interface. Applications to polymethylphenylsilane light
emitting diodes are discussed. 16 refs.
JAPAN
Accession no.647206
Item 213Polymers for Advanced Technologies
8, No.6, June 1997, p.351-4
POLYSILOXANE GEL WITH LOWCROSSLINKING DENSITY FOR MAKE-UPCOSMETICSKobayashi R; Yabe S; Nomura T
Kose Corp.
The mechanism whereby a crosslinked silicone having a
specific crosslink density was swollen in the presence of a
silicone oil having a low viscosity to form a stable gel was
applied to the manufacture of cosmetic foundations.
Optimum conditions that provided favourable properties
and satisfactory organoleptic sensation were studied.
Polymethylhydrogensiloxanes with a low crosslink density
were prepared by subjecting alpha,omega-divinyl-
polydimethylsiloxane to addition polymerisation. The
viscoelasticities of the gels formed from the resultant
products and silicone oil were investigated. Based on the
results, it was concluded that the most suitable product was
a low crosslink density material obtained by adding
alpha,omega-divinylpolydimethylsiloxane to polymethyl-
hydrogensiloxane having an average molec.wt. of 2.5 kDa
under conditions in which the concentration of
dimethylpolysiloxane was 60%. This product provided an
enhanced viscosity at a reduced solids content. 5 refs.
JAPAN
Accession no.645630
Item 214Advanced Materials
9, No.9, 4th July 1997, p.741-6
STABILITY OF MOULDEDPOLYDIMETHYLSILOXANEMICROSTRUCTURESDelamarche E; Schmid H; Michel B; Biebuyck H
IBM Corp.
One aspect of the use of elastomeric materials for the
formation of the stamps central to existing demonstrations
of microcontact printing and micromoulding in capillaries
(MIMIC) is examined: the stability of features in
elastomeric stamps to the processes of their formation and
subsequent application. The key function of elastomeric
stamps is to provide a pattern of relief on the surface of a
flexible solid used to transfer or mould the shape of material
in its image. Fabrication of a stamp requires its replication
from a master. Liquid polydimethylsiloxane (PDMS) is
poured on top of the master, which is formed in photoresist,
directly in silicon, or in some other material. The low-
energy siloxane fluid fills the crevices of the master,
forming a negative replica of the surface. Further
crosslinking of the siloxane by light-initiated or metal-
catalysed reaction results in an elastomeric solid that
preserves on its surface - in the best cases - an accurate
record of the topology after its separation from the master.
The pattern of reliefs in the surface of the stamp is then
useful in transferring inks to a substrate by contact between
raised regions of the stamp and the surface of the substrate.
Alternatively, these reliefs act as moulds or conduits for
solids or liquids and thus as a direct template to form
patterns in these materials. 16 refs.
SWITZERLAND; WESTERN EUROPE
Accession no.645230
Item 215NRC ’96. Conference proceedings.
Helsinki, 23rd-24th May,1996, paper 9. 8
SILICONE RUBBER IN SPECIALAPPLICATIONSDietl S
Wacker-Chemie GmbH
(Finnish Association for Rubber Technology; Nordic
Council of Rubber Technology)
Silicone rubber is well-known as a special elastomer for
the solution of problems in individual applications. Its
unique combination of outstanding properties leads to
hundreds of cases where silicone rubber is the only choice.
On account of its versatility, silicone rubber may be
tailored to the demand of special tasks. The lecture covers
well-known applications as well as fascinating new ones.
Silicone rubbers can be used in a number of applications,
including high-temperature, low-temperature, electrical,
flame retardant, health care, food-contact, baby-care,
household, construction and automotive applications.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.641386
References and Abstracts
110 © Copyright 2001 Rapra Technology Limited
Item 216Journal of Biomedical Materials Research
35, No.4, 15th June 1997, p.505-11
THEORETICAL ANALYSIS OF HYDROLYSISOF POLYDIMETHYLSILOXANE(PDMS)West J K
Florida,University
The hydrolysis of PDMS, commonly used in breast
implants, was theoretically modelled using a semi-
empirical quantum mechanical model (AM1). The
activation barrier for removing a methanol monomer was
found to be +82 Kcal/mol, while the removal of a
methane monomer was +41 Kcal/mol. Using the same
AM1 method, hydrolysis of the -Si-O-Si- bond was also
modelled for pentasilicic acid and 1,1,3,3-
tetramethyldisiloxane-1,3-diol. The barrier to the
removal of a silicon-containing tetrahedron for both
studies was found to be +27 Kcal/mol. This was
approximately one and a half times smaller than the
energy of that needed to remove a methyl group. The
pentacoordinated silicon-activated transition state for
hydrolysis of PDMS could provide an energetically
favourable pathway for development of a surface that
would enhance chemisorption of charged protein
molecules and such a pathway map could show up in
NMR studies of the hydrolysis of PDMS. 28 refs.
USA
Accession no.640133
Item 217151st ACS Rubber Division Meeting, Spring 1997,
Conference Preprints.
Anaheim, Ca., 6th-9th May 1997, Paper 88, pp.24. 012
NMR OF TISSUES EXPOSED TOPOLYSILOXANE GELSGarrido L
Massachusetts General Hospital; Harvard Medical
School
(ACS,Rubber Div.)
The migration of polysiloxanes from polysiloxane gel
filled breast implants to local and distant sites in living
systems was studied by NMR spectroscopy. Tissues from
animals and humans exposed to the implants were studied
in-vivo using proton NMR localised spectroscopy and in-
vitro with proton and silicon-29 magic angle spinning
NMR spectroscopy. The results showed that free
polysiloxanes present in the implants migrated to
surrounding tissues and distant organs such as the liver.
In addition, silicon-29 NMR spectra of metabolically
active tissues (liver) showed the presence of chemically
unchanged polysiloxanes and other silicon-containing
compounds (silica), suggesting that these polymers were
biodegradable. 45 refs.
USA
Accession no.639065
Item 218151st ACS Rubber Division Meeting, Spring 1997,
Conference Preprints.
Anaheim, Ca., 6th-9th May 1997, Paper 74, pp.2. 012
ADVANTAGES OF SILICONE ELASTOMERS INTHE CONSTRUCTION OF ROLLERSLapsley T; Dickson S
American Silicones
(ACS,Rubber Div.)
An examination is made of the range of properties
obtainable in rollers covered with silicone rubbers.
USA
Accession no.639054
Item 219151st ACS Rubber Division Meeting, Spring 1997,
Conference Preprints.
Anaheim, Ca., 6th-9th May 1997, Paper 62, pp.8. 012
SILICONE RUBBER APPLICATIONS: WHYSILICONES ARE USEDFinney D; Papa J
General Electric Co.,Silicone Products Div.
(ACS,Rubber Div.)
Uses of silicone rubbers in automotive and aerospace
applications, high voltage insulators and business machine
components are reviewed, and the reasons for selecting
silicone rubbers for such applications are discussed. 3 refs.
USA
Accession no.639044
Item 220Antec 97. Volume I. Conference proceedings.
Toronto, 27th April-2nd May 1997, p.308-14. 012
POLYFLOW: TREATISE ON INVERSE DIE/MANDREL DESIGN FOR HIGH CONSISTENCYSILICONE ELASTOMERAndrejewski D A
Dow Corning Corp.
(SPE)
To date, manufacturing experiences low production yields
when extruding complex cross-sections with high
consistency silicone rubber. In the extrusion process, shear
is imparted and introduced to the material, causing both
shear thinning and elastic effects which make the die/
mandrel design uncertain. Computational Fluid Dynamic
methods (Polyflow) were utilised to model the flow
characteristics of the material through the die/mandrel to
determine their proper shape with respect to the required
extrudate. Non-linear viscoelastic constitutive models
correlating rheology with the actual flow dynamics were
utilised in the software to achieve this end. The die/
mandrel design developed through the modelling
techniques demonstrated their invaluable need by
boosting production rates as high as 167%, and decreasing
waste and set-up time 18-fold respectively. Finally, the
References and Abstracts
© Copyright 2001Rapra Technology Limited 111
process developed should be utilised to improve existing
and future designs where complex profiles cause long set-
up times and high scrap rates. 5 refs.
USA
Accession no.636428
Item 221Biomaterials
18, No.8, 1997, p.635-41
PHYSICOCHEMICAL PROPERTIES OF ARIFAMPICIN-RELEASINGPOLYDIMETHYLSILOXANE SHUNTSchierholz J M
Cologne,University
Results of studies of the above are presented and
discussed, particular attention being paid to the cohesion
energy (solubility parameter) of the polydimethylsiloxane
network and rifampsin, controlled delivery of rifampsin
from the silicone network, mechanical properties of the
conventional and modified silicone shunt, differential
calorimetric determinations of drug, polymer and the
drug-polymer system, and SEM of the polymer and the
polymer-rifampsin system. Rifampsin is a competitive
inhibitor of bacterial RNA polymerase. 30 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.634645
Item 222China Rubber Industry
44, No.4, April 1997, p.233-6
Chinese
STUDY ON RUBBER COMPOUNDS OF HIGHVOLTAGE CAP AND WEDGE FOR TELEVISIONSETWu Shishan; Dou Qiang; Liu Gang; Ma Liming
Nanjing,Institute of Chemical Technology; Nanjing
Jiangpu Dougang Plastics Factory
Silicone rubber compounds of high voltage cap and wedge
for colour television sets were developed. The effect of
flame retardant and filler on the physical properties, flame
retardance and electrical properties was investigated. The
results showed that good flame retardance was obtained
with antimony oxide/DBDPO blend flame retardant
system, 3-4 phr of silica being adequate. The formulation
developed included silicone rubber (151 mix type) 100
parts, 2,5-dimethyl-2,5-bis(tert-peroxy)hexane 1 part,
antimony oxide 2 parts, DBDPO 4 parts, silica 4 and 3
parts, respectively, for high voltage cap compound and
wedge compound. 3 refs.
CHINA
Accession no.632501
Item 223Rubber and Plastics News
26, No.14, 24th Feb.1997, p.19
MOHAWK TURNING OUT RUBBERCOMPONENTSWhitford M
Mohawk Plastics Inc. is a manufacturer of thermoplastic
and thermoplastic elastomer gasket carriers for car
makers. Details are given of its expansion plans which
involve the adding of liquid silicone injection moulding
machines for engine gasket construction. The company
is currently increasing capacity for carriers at its Marine
City factory and plans to double floor space there.
MOHAWK PLASTICS INC.USA
Accession no.631852
Item 224Plastics and Rubber Asia
12, No.69, March 1997, p.32
LIQUID SILICONE DEMONSTRATES SAVINGPOWER
Advantages of the use of liquid silicone rubber Silopren
LSR were demonstrated at Aseanplas, by Bayer. Using
an adapted Engel 90 tonnes clamping force injection
moulding machine, a cycle time of 22 seconds was
achieved to produce injection moulded parts. LSR is
reported to be popular in Asia, with applications in baby
bottle teats and keyboards, and Bayer hopes that the powerindustry will use it in the future to replace porcelain high
voltage insulators.
BAYER AG
Accession no.631813
Item 225Analytical Chemistry
69, No.7, 1st April 1997, p.1267-72
DETECTION AND CHARACTERIZATION OFPOLYDIMETHYLSILOXANES IN BIOLOGICALTISSUES BY GAS CHROMATOGRAPHY(GC)/ATOMIC EMISSION DETECTION(AED) ANDGC/MASS SPECTROMETRY(MS)Kala S V; Lykissa E D; Lebovitz R M
Baylor College of Medicine
A sensitive method was developed for detection,
characterisation and quantification of low molec.wt.
silicones using GC/AED and G C/MS. Using this
approach, twelve distinct silicon-containing peaks were
detected in polydimethylsiloxane oil by GC/AED, and
GC/MS analysis was used to identify some of the
abundant peaks by MS spectral matching. The described
methodology was shown to have the potential to allow
the measurement of less than 1 micro g of silicone/g of
biological tissue. 8 refs.
USA
Accession no.631642
References and Abstracts
112 © Copyright 2001 Rapra Technology Limited
Item 226European Rubber Journal
179, No.4, April 1997, p.27-8
SILICONES STILL A GROWING AREAWhite L
The major French silicone sealant supplier, Rhone
Poulenc, says is is focusing on innovation and new
products. It is particularly optimistic about prospects for
its new generation of water-based silicone sealants. Dow
Corning estimates growth in silicone sealants as averaging
about 5-6%, with regional variations. The sealants
business is heavily dependent on the health of the
construction sector. Europe and Japan, for example, are
experiencing poorer conditions than others for sealant
sales.
WESTERN EUROPE-GENERAL
Accession no.631579
Item 227European Plastics News
24, No.4, April 1997, p.24-5
FLEXIBLE SOLUTIONSAnscombe N
With the correct processing equipment, liquid silicone
rubbers can be easily moulded into a huge variety of
products. Standard injection moulding machines need to
be modified before they can be used for LSR processing.This is done with relative ease and involves changes to
the dosing equipment, barrel, screw and mould nozzles.
MANNESMANN DEMAGEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.630218
Item 228Patent Number: US 5539020 A 19960723
METHOD AND DEVICE FOR CUSHIONINGLIMBSBracken R L; Winn R A; Riley N L
Schering-Plough HealthCare Products Inc.
A soft, tacky polysiloxane elastomer, which has a
tackiness of 10 to 450 grams, as determined by a polyken
probe tack tester, or 0 to 10 cm, as determined by a rolling
ball tack tester, and a tensile strength of 0.14 to 5.52 mega
Pascals (20 to 800 pounds/sq.in.), a minimum elongation
of 250 to 1100% and a tear strength of 0.88 to 35.2 kN/m
(5 to 200 pounds/sq.in.) is disclosed. It can be made into
various cushioning devices with or without a topcover,
including an arch support pad, a metatarsal pad, a heel
cushion, sheet padding, a full-length insole, a three quarter
length insole, a half insole, a toe-crest pad, a heel liner,
an elbow pad, a corn pad, a callus pad, a blister pad, a
bunion pad or a toe pad.
USA
Accession no.629328
Item 229British Plastics and Rubber
March 1997, p.21-2
PROCESSING AS A LIQUID CUTS THE COSTOF SILICONE RUBBER
Liquid silicone rubber is a transparent rubber material
with degrees of hardness between 20 and 90 Shore A,
which crosslinks rapidly when mould temperature reaches
about 200C. The 2KM Silco-Mix metering system from
Prodef Engineers permits both material components to
be dosed directly from their original drums. Demag
Ergotech 25 and 35 tonne injection moulding machines
with a specially designed screw and barrel are now
available for LSR moulding. Processing requirements are
discussed.
PRODEF ENGINEERS LTD.; MANNESMANN
DEMAG; MIR SPA; SILICONE ALTIMEX LTD.WESTERN EUROPE-GENERAL
Accession no.628609
Item 230Patent Number: US 5531923 A 19960702
TWIN-SCREW EXTRUSION OF SILICONEDOUGHS SUITED FOR SIH/SIVI RTVCOMPOSITIONSLe Blanc L; Pagliari R
Rhone-Poulenc Chimie
Silicone doughs suitable for incorporation into
diorganopolysiloxane compositions crosslinkable into
elastomeric state are rapidly and conveniently formulated
by continuously and simultaneously individually
introducing along the longitudinal axis of a twin screw
extruder, via a plurality of longitudinally spaced discrete
inlet entries, and twin screw extruding (a) a
polydiorganosiloxane oil having a viscosity at 25C of less
than 500000 mPa.s and containing at least two given
functional groups per molecule, (b) water, (c) silica, and
(d) a polysilazane which is liquid under normal conditions
of temperature and pressure.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.628335
Item 231Advanced Materials
9, No.2, Feb.1997, p.147-9
REPLICA MOULDING USING POLYMERICMATERIALS: PRACTICAL STEP TOWARDNANOMANUFACTURINGXia Y; McClelland J J; Gupta R; Qin D; Zhao X-M;
Sohn L L; Celotta R J; Whitesides G M
Harvard University; US,National Inst.of Standards &
Technology; Princeton,University
Details are given of the technique of replica moulding
for manufacturing nanostructures with emphasis given
References and Abstracts
© Copyright 2001Rapra Technology Limited 113
to the use of elastomeric masters. Data are given for
PDMS, PMMA, and PU. 13 refs.
USA
Accession no.626453
Item 232Patent Number: US 5516838 A 19960514
FLAME RETARDANT SILICONECOMPOSITIONSHironao Fujiki; Masayuki Ikeno; Hiroyasu Hara;
Kasuyasu Satoh
Shin-Etsu Chemical Co.Ltd.
To a silicone composition comprising (A) an
organopolysiloxane having at least two alkenyl groups in
a molecule, (B) an organohydrogenpolysiloxane having
at least two hydrogen atoms each directly attached to a
silicon atom in a molecule, and (C) a platinum catalyst,
(D) a compound having a phenyl group and a secondary
or tertiary amino group directly attached thereto is added
to render the composition flame retardant. The
composition cures into a transparent product having
improved flame retardancy meeting the UL standard and
is suitable for use in the protection of electronic parts
like IC’s and hybrid IC’s.
JAPAN
Accession no.625227
Item 233Patent Number: US 5525427 A 19960611
ABRASION RESISTANT SILICONEWEATHERSTRIP COATINGGriswold R M; Lin S B
General Electric Co.
A water reducible weatherstrip coating comprises a two
or three component system comprising a silicone emulsion
base, a bath-life extender, and a crosslinking composition.
USA
Accession no.624955
Item 234Injection Moulding International
1, No.1, Nov./Dec.1996, p.36
INTELLIGENT REDESIGN CUTS COST INHALFNeilley R
A computer keyboard mat, situated under the keys, flexes
to transmit the signal then returns the key to its start
position. Traditionally, keyboard mats have been
compression moulded in NR. Starlim GmbH, a liquid
injection moulder of liquid silicone rubber, has redesigned
the part, cutting the finished part weight by more than
half and significantly improving the mat’s performance
and durability. The new design is a pattern of domes and
thin connecting strips.
STARLIM GMBHEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.624824
Item 235Plastics and Rubber Weekly
No.1676, 7th March 1997, p.20
SEMINAR SELLS LIM
GE Silicone and Mannesmann Demag Hamilton recently
joined forces to introduce thermoplastic moulders to the
benefits of liquid injection moulding of silicone
elastomers. From a cost point of view alone, switching
from processing thermoplastics to silicone LIM is a
smaller hurdle than from conventional heat cure
elastomers to LIM. Production of an automotive spark
plug connector was used to demonstrate that silicone LIM
can be carried out on relatively lightly modified moulding
equipment.
GE SILICONES; MANNESMANN DEMAG
HAMILTON LTD.EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.624534
Item 236Journal of Biomedical Materials Research
34, No.2, Feb.1997, p.201-10
ADHESION TO SILICONE RUBBER OF YEASTSAND BACTERIA ISOLATED FROM VOICEPROSTHESES: INFLUENCE OF SALIVARYCONDITIONING FILMSBusscher H J; Geertsema-Doornbusch G I; van der Mei
H C
Groningen,University
Adhesion of two streptococcal, staphylococcal, Candida
albicans and Candida tropicalis strains, isolated from
explanted voice prostheses was investigated to silicone
rubber with and without a salivary conditioning film in a
parallel-plate flow chamber. Within each microbial pair
of one species, the strain with the most negative zeta
potential adhered most slowly to negatively charged
silicone rubber. No other clear relationships were obvious
between adhesion to silicone rubber and microbial zeta
potentials or cell-surface hydrophobicities, as by water
contact angles. 37 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.622299
Item 237Plast’ 21
No.47, Nov.1995, p.85-6
Spanish
PRODUCTION OF PLASTICS AND METALPROTOTYPES BY VACUUM CASTING
References and Abstracts
114 © Copyright 2001 Rapra Technology Limited
Ferrandiz S
AIJU
An account is given of techniques used by AIJU of Spain
for the vacuum casting of plastics and metal prototypes
for the toy industry using silicone rubber moulds.
EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN;
WESTERN EUROPE
Accession no.621102
Item 238Materie Plastiche ed Elastomeri
No.9, Sept.1995, p.524-7
Italian
YEAR OF EXTRUSION
A survey is made of developments by GE Plastics in
engineering plastics grades for extrusion and injection
moulding. Uses of these materials in electrical,
telecommunications, lighting and automotive applications
and domestic appliances are examined. Details are also
given of silicone polymer coatings, liquid silicone rubbers
and silicone rubber gels developed by GE Silicones.
GE PLASTICS; DELPHI INTERIOR & LIGHTING
SYSTEMS; GE SILICONESUSA
Accession no.621090
Item 239Biomaterials
17, No.23, 1996, p.2265-72
TISSUE RESPONSE TO COMMERCIALSILICONE AND POLYURETHANEELASTOMERS AFTER DIFFERENTSTERILISATION PROCEDURESZhang Y Z; Bjursten L M; Freij-Larsson C; Kober M;
Wesslen B
Lund,University
A silicone and a polyurethane elastomer were studied with
regard to correlations between the chemical and physical
compositions of the polymer surfaces and the biological
response on implantation. Test specimens of the materials
were manufactured according to standard procedures. The
specimens were implanted into rats for 10 and 90 days.
Before implantation, the polymers were sterilised by beta
irradiation, ethylene oxide sterilisation and steam
sterilisation. The polymers were characterised before and
after implantation with respect to chemical composition
and morphology of the surfaces. After implantation the
biological response was evaluated by counting numbers
of macrophages, giant cells, fibroblasts and other cells
present at the surfaces. The thickness of the fibrous
capsule surrounding the test specimens was measured at
the thickest and thinnest parts. 17 refs.
SCANDINAVIA; SWEDEN; WESTERN EUROPE
Accession no.616597
Item 240Degradation and Stabilization of Materials. Applied
Polymer Symposium proceedings.
Alexandria, 26th-30th Sept.1992, p.231-42. 012
STUDY OF SOME PROPERTIES OF ALGINATEAND SILICONE RUBBER BASE IMPRESSIONSAFTER IMMERSION DISINFECTIONTaymour N M; El-Shabrawi
Alexandria,University
Edited by: Kandil S H
(Alexandria,University)
Applied Polymer Symposium 55
Dental impressions of an engraved metal die were made
with alginate and silicone rubber base impression
materials. After separation from the metal die, all
impressions were soaked (before pouring with Type IV
gypsum) into a variety of test disinfectants via a 30-min
immersion time. Following immersion disinfection, the
linear dimensions of each stone cast (both intra-arch and
cross-arch dimensions) were measured. Surface hardness
characteristics of all the resultant casts were also
examined. Analysis of the results showed that all the
broad-spectrum disinfectant agents used offered effective
antimicrobial activity without distorting the impressions.
There was no significant linear dimensional change or
any alteration in the surface hardness characteristics of
all the examined stone casts. 19 refs.
EGYPT
Accession no.611280
Item 241Rubber Technology International
1996, p.109-11
PLATINUM CURED SILICONE COMPOUNDSSullivan G
Dow Corning STI
Recent advances in platinum-catalysed silicone
compounds have produced high performance liquid
silicone rubber materials and rapid curing high
consistency rubber formulations. Both are helping
moulders to reduce fabricating costs and increase
processing speeds over conventional peroxide-cured
silicones. This comprehensive article supplies full details.
USA
Accession no.610806
Item 242Rubber and Plastics News
26, No.5, 7th Oct.1996, p.28
ACTIVISTS ASK FDA TO RETHINK IMPLANTBANMoore M
Two members of Congress are reported to have joined
anti-cancer activists in Washington to call on the Food
and Drug Administration to reconsider its moratorium on
References and Abstracts
© Copyright 2001Rapra Technology Limited 115
silicone gel breast implant use. A petition calls on the
agency to ease restrictions on silicone implants for breast
cancer patients. It relies on the body of sound scientific
evidence that has been produced since the FDA
commissioner severely limited access to these medical
devices four years ago. This evidence strongly suggests
that there is no causal link between silicone-gel implants
and systemic connective tissue diseases or classic
autoimmune symptoms. Silicone breast implants are
currently available only to patients involved in the FDA
clinical trials to monitor the effects of silicone on women.
Details are given.
USA
Accession no.610082
Item 243Injection Molding
4, No.9, Sept.1996, p.98/104
FOR LSR, HIGH TECHNOLOGY OUTWITSLOW LABOUR COSTSNeilley R
An Austrian company, Starlim GmbH, has won back from
Asia a keyboard contact mat production job, which was
sourced from Asia due to its low labour costs, since the
compression moulded natural rubber mats required post-
mould trimming and involved much handling. Starlim
uses liquid injection moulding of silicone rubber,
sophisticated moulds, and an injection system to produce
the product at half the cost, whilst improving performance
and durability. Details are given of the production by
Starlim, and the redesign of the mat into a pattern of domes
and connecting strips.
STARLIM GMBHASIA; AUSTRIA; WESTERN EUROPE
Accession no.608155
Item 244Advanced Packaging
5, No.5, Sept/Oct.1996, p.30/2
FINDING A CUREVanwert B; Wilson S W; Hanlon A
Dow Corning Corp.
Electronic applications are reported to demand that
adhesive products possess a number of properties in
addition to good adhesion and compatibility with substrate
materials. Most adhesives used in a production
environment are heat cured, both for processing speed
and ultimate physical properties. Flexibility is also
necessary to prevent damage during temperature cycling,
even if the assemblies are not subjected to extreme heat
or cold. Finally, the ability to maintain physical properties
in the presence of moisture, contaminants and varying
temperatures is imperative for many applications. Aspects
of silicone adhesives in electronic applications described
include application requirements, physical properties,
processing requirements, cure mechanisms and testing.
Accession no.607356
Item 245Chemistry of Materials
8, No.8, Aug.1996, p.1735-8
NANOCOMPOSITES PREPARED BYTHREADING POLYMER CHAINS THROUGHZEOLITES, MESOPOROUS SILICA, OR SILICANANOTUBESFrisch H L; Mark J E
New York,State University; Cincinnati,University
A brief review is given of preliminary attempts to prepare
nanocomposites in which PDMS chains thread through
the cavities or channels of several types of inorganic
materials. Emphasis is given to the use of zeolites, a
mesoporous hexagonal form of silica, and silica
nanotubes. The effects of the constraining geometry on
the properties of the chains, particularly their Tg were
determined. 91 refs.
USA
Accession no.603765
Item 246Antec ’96. Vol.I. Conference Proceedings.
Indianapolis, 5th-10th May 1996, p.381-5. 012
TWIN-SCREW EXTRUSION PROCESSING OFFILLED POLYMERSLawal A; Railkar S; Yaras P; Kalyon D M
Stevens Institute of Technology
(SPE)
Results are presented of an integrated study of the
extrusion behaviour of a viscoplastic polydimethyl
siloxane suspension filled with hollow glass spheres. The
rheological properties of the suspension, including the
Navier wall slip condition, were characterised by multiple
viscometric flows. The pressure and temperature history
in the co-rotating twin-screw extrusion process was
simulated using finite element analysis and compared with
experimental data collected with a well instrumented 50.8
mm twin-screw extruder. The model results agreed well
with the experimental data and provided a detailed
understanding of the thermomechanical history
experienced by the suspension during twin-screw
extrusion. 43 refs.
USA
Accession no.602941
Item 247Biomaterials
17, No.16, 1996, p.1627-30
DYNAMIC MECHANICAL THERMALANALYSIS OF DENTURE SOFT LININGMATERIALSWaters M; Jagger R; Williams K; Jerolimov V
Wales,University; Zagreb,University
References and Abstracts
116 © Copyright 2001 Rapra Technology Limited
Details are given of the characterisation of the deformation
properties of a range of long-term denture soft lining
materials using dynamic mechanical thermal analysis.
Specimens were subjected to sinusoidal shear deformation
to simulate the type and rate of deformation soft lining
materials would experience clinically. Data are given for
various acrylic resins and silicone elastomers. 7 refs.
CROATIA; EUROPEAN COMMUNITY; EUROPEAN UNION;
UK; WESTERN EUROPE
Accession no.602615
Item 248Industria della Gomma
39, No.5, May 1995, p.47-8
Italian
LIQUID SILICONE RUBBERS FOR INJECTIONMOULDING
Processing conditions and machinery used in the injection
moulding of liquid silicone rubbers are described. Types of
products which can be manufactured by this process are
examined, and causes of moulding faults are briefly reviewed.
GE SILICONESUSA
Accession no.598421
Item 249Industria della Gomma
39, No.5, May 1995, p.45-6
Italian
MARGUM 1715U: A SILICONE RUBBER FORWIRE AND CABLE EXTRUSIONCabrini G
Dow Corning STI
Data are presented for the mechanical and electrical
properties and flammability characteristics of Margum
1715U, a silicone rubber compound developed by Dow
Corning STI for applications in wire and cable extrusion.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.598420
Item 250Industria della Gomma
39, No.5, May 1995, p.42-5
Italian
PROPERTIES AND SELECTION OF SILICONERUBBERSSteinberger H
Bayer AG
The structure, properties, vulcanisation and processing of
silicone rubbers are examined. Properties and applications
of Silopren silicone rubbers produced by Bayer are described.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.598419
Item 251Patent Number: US 5459167 A 19951017
PROCESS FOR PRODUCING A FORMEDSILICONE FOAM BY INJECTION MOULDINGGiesen F J
Fuller H.B.,Licensing & Financing Inc.
To manufacture high quality, fine pored silicone foam
parts by the injection moulding process, two reaction
components A and B are used. They both contain a silicone
polymer and fumed silica. The component A also contains
a complexed organo-platinum catalyst and a small portion
of water, whereas the other component B contains as a
crosslinker polydimethyl hydrogen siloxane. At least one
of the two components A and B of the mixture is
pressurised with a gas, preferably air or nitrogen, in a
pressure container so that the gas is dissolved into the
component(s). The components A and B are mixed in the
pressure process, injected into an injection mould, and
heated so that the foaming process forms the silicone foam
part.
USA
Accession no.596618
Item 252Journal of Applied Polymer Science
61, No.4, 25th July, 1996, p.703-13
COLLAPSIBLE-TUBE PULSATIONGENERATOR FOR CROSSFLOWMICROFILTRATION: FATIGUE TESTING OFSILICONE RUBBER TUBESHadzismajlovic D E; Bertram C D
New South Wales,University
Fatigue tests were performed on 18 silicone rubber tubes
operating as the active element of a crossflow pulsation
generator. 22 refs.
AUSTRALIA
Accession no.596012
Item 253Analyst
121, No.6, June 1996, p.53R-63R
SILICONES AND THEIR DETERMINATION INBIOLOGICAL MATRICES: A REVIEWCavic-Vlasak B A; Thompson M; Smith D C
Toronto,University
A review of the literature on silicones and their
determination in biological matrices is presented. The
following topics are covered: properties and applications
of silicones; biochemistry of elemental silicon and
silicones; general approach to the determination of trace
amounts of silicones in biological materials; survey of
methods used for non-specific and silicon-specific
microstructural determination of silicones in tissues
(microanalysis); silicone-specific (elemental) techniques
for the detection of silicones in biological materials;
References and Abstracts
© Copyright 2001Rapra Technology Limited 117
survey of silicone-specific techniques (IR, FTIR, Raman,
NMR spectroscopies, gas chromatography(GC) and GC-
mass spectrometry methods); and problem of speciation
of silicon and identification of silicone biotransformation
products in biological samples. 124 refs.
CANADA
Accession no.595316
Item 254Patent Number: US 5472994 A 19951205
MICROWAVE-HEATABLE EXERCISE PUTTYMicallef A M; Gibbon R M
JMK International Inc.
A microwaveable exercise putty includes a borosiloxane
or stannosiloxane reaction product. The resulting reaction
product is mixed with a second polysiloxane, an internal
lubricant such as a monounsaturated fatty acid, and a
particulate material which creates heating upon subjection
to microwave energy. Precipitated silica is a particularly
preferred particulate material. The exercise putty may be
manipulated by patients, and at the same time is capable
of delivering heat to the body part undergoing the
manipulation.
USA
Accession no.594354
Item 255IRSG 36th International Rubber Forum 1995: Factors
Affecting the Development of the Rubber Industry in
the Pacific Rim. Conference Proceedings.
Tokyo, 27th Feb.-3rd March 1995, p.143-158
SILICONE ELASTOMERS: THEIR PRESENTAPPLICATIONS AND FUTURE POTENTIALTanimura M
Dow Corning Toray Silicone Co.Ltd.
This paper discusses silicone markets, major suppliers,
silicone as an elastomer, silicone rubber applications,
trends in technology and the future outlook. In the US,
the automotive sector is the most important for silicone
rubbers and accounts for 40% of the total market. In Japan,
55% of the total market is accounted for by the electrical/
electronic sector. In the Pacific region, excluding Japan,
68% goes into electrical/electronic manufacturing. New
and emerging applications include automotive airbag
coating, electrical insulators and copier/printer wells.
JAPAN
Accession no.593330
Item 256Patent Number: EP 718369 A1 19960626
METHOD OF REDUCING HOTHYDROCARBON OIL SWELL OF FILLEDSILICONE SEALANT GASKETSLower L D
Dow Corning Corp.
The gaskets are made from a room temperature
vulcanisable silicone sealant composition containing a
hydroxyl endblocked polydimethylsiloxane, calcium
carbonate or a combination of calcium carbonate and
reinforcing silica filler, a specifically selected
ketoximosilane crosslinker combination, such as
vinyltriketoximosilane and methyltriketoximosilane and
a catalyst. They cure rapidly enough to be used on an
automated production line for formed-in-place gaskets.
USA
Accession no.592982
Item 257British Engel Elast Symposium 1995. Symposium
Proceedings.
Warwick, 21st-22nd June 1995, paper 6, pp.16. 831
LIQUID SILICONE RUBBER - PROCESSING,APPLICATIONS AND DEVELOPMENTSNaumann T
Bayer AG
(Engel Vertriebsges mbH)
This paper presents information in some detail on
processing properties and injection moulding applications
of Silopren LSR liquid silicone rubber from Bayer.
Applications listed include electronics, electrical
appliances, automotive products, medical and textile
applications. Newly developed Silopren LSR products,
mould technology and product design are outlined.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.590902
Item 258Polymer Science Series A
38, No.3, March 1996, p.225-31
THERMALLY STABLE ELASTOMERS: INRETROSPECT OF TWO DECADESSokolov S V; Kolokol’tseva I G
Russia,State Research Institute of Synthetic Rubber
State-of-the-art advances that marked the past two decades
in the synthesis and application of thermally stable
siloxane and fluorocarbon elastomers are reviewed. The
main trend consists in changing the priorities from
aerospace applications to automotive and other consumer
goods applications, which determine the new
requirements for the properties of thermally stable
elastomers. 12 refs.
RUSSIA
Accession no.590686
Item 259Rubber and Plastics News
25, No.18, 25th March 1996, p.15
STUDY STIRS BREAST IMPLANTCONTROVERSY
References and Abstracts
118 © Copyright 2001 Rapra Technology Limited
Moore M
It is reported that pro- and anti-breast implant forces are
drawing opposite conclusions from a new epidemiology
study, the results of which were recently published by
researchers at the Harvard University-affiliated Brigham
& Women’s Hospital in Boston. Former silicone implant
manufacturers claim that the study shows that there is no
major risk of disease among women with breast implants.
Opponents of silicone gel breast implants, however, say
that the report invalidates their position. Details are given.
HARVARD UNIVERSITY; BOSTON,BRIGHAM &
WOMEN’S HOSPITALUSA
Accession no.589896
Item 260Patent Number: EP 699512 A1 19960306
LIQUID SILICONE RUBBER INJECTIONMOULDING MACHINEGrenda D
Whitaker Corp.
A distribution member for the above machine comprises
a channel distribution network for feeding liquid silicone
rubber to a mould die. The silicone rubber is vulcanised
by heating the mould die to around 120C and heat must
be prevented from flowing into feed pipes and nozzles of
the distribution network to ensure that the injection fluiddoes not vulcanise within the feed channels. Plastic heat
insulating feed pipes and nozzles are provided to prevent
overheating of the fluid in the feed channel. The liquid
silicone rubber does not bond to these pipes and nozzles.
The feed pipes can be provided with a reflective outer
surface and separated from plate members by an air gap
to further reduce heat transfer. Advantages of the machine
are reduction in machine cost, easy and cheap replacement
of nozzles and feed pipes and increased reliability.
USA
Accession no.589497
Item 261IRC ’95 Kobe International Rubber Conference.
Conference proceedings.
Kobe, 23rd-27th Oct.1995, p.91-4. 012
ADHESION OF ADDITION CURE SILICONESTO THERMOPLASTICFujiki H; Shudo S
Shin-Etsu Chemical Co.Ltd.
(Japan,Society of Rubber Industry)
A new addition curing silicone rubber having selective
bonding to polycarbonate, PBTP, etc. without adhering
to the mould (metal) in thermoplastics insert molding and
co-injection moulding is described.
JAPAN
Accession no.586128
Item 262Medical Device Technology
7, No.2, March 1996, p.22/8
PURCHASING SILICONEPryce T
SF Medical Ltd.
Differences in medical grade and food contact grade
silicone polymers are discussed with reference to CE
marking. Medical device manufacturers need to be able
to document that they employ the correct materials and
components for a particular application, and to
demonstrate that their suppliers possess the necessary
product range, technical expertise and quality procedures
necessary to assure product integrity. An explanation is
offered of the inspection and testing terms relating to
material specification and testing of silicone polymers. 3
refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.584577
Item 263Revista de Plasticos Modernos
68, No.462, Dec.1994, p.568-71
Spanish
LIQUID SILICONE RUBBER: A HIGHPERFORMANCE MATERIAL OF THE FUTURESchulze M
Bayer AG
The processing and applications of Bayer’s Silopren LSR
liquid silicone rubbers are examined. The environmental
advantages of these materials and quality control
procedures used in their manufacture are described.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.583103
Item 264Trends in Polymer Science
4, No.2, Feb.1996, p.52-9
SILICONE HYDROGELS FOR CONTACT LENSAPPLICATIONKuenzler J F
Bausch & Lomb Inc.
The synthetic and formulation approaches that have been
pursued in the design of silicone hydrogels for use in
extended wear contact lenses are reviewed. The synthesis
of hydrophilic block and graft siloxanes and the use of
these hydrophilic silicones in the preparation of hydrogel
formulations are shown to have led to the development
of transparent, wettable and low-modulus materials
possessing extremely high levels of oxygen permeability.
23 refs.
USA
Accession no.582511
References and Abstracts
© Copyright 2001Rapra Technology Limited 119
Item 265Medical Plastics Industry at the Dawn of the 21st
Century. Retec proceedings.
Rosemont, Il., 25th-26th Oct. 1994, p.133-68 6S
DESIGN OF AN INJECTION MOULDEDSTRUCTURAL SPINE SUBASSEMBLY FORINTRACOCHLEAR STIMULATINGELECTRODES: THE BASIS OF LOW COSTAUTOMATED ASSEMBLYBruszewski W; Rebscher S; Heilmann M; Merzenich M
California,University
(SPE; SPI)
Details are given of the design and manufacture of a
multichannel intracochlear stimulating electrode that can
be assembled by electronic pick and place robots. A
subassembly incorporating stimulating contacts and a 16-
channel conductor array was injection moulded from
silicone rubber. Other polymers analysed were polyether
imide, PP, polysulphone, and polyimide. 15 refs.
USA
Accession no.582186
Item 266Journal of Biomedical Materials Research
30, No.3, March 1996, p.305-12
PILLARED-SURFACE MICROSTRUCTURE ANDSOFT-TISSUE IMPLANTS: EFFECT OFIMPLANT SITE AND FIXATIONPicha G J; Drake R F
Baxter Healthcare Corp.
Details are given of the effect of microtissue anatomy
and silicone rubber implant site on fibrosis and blood
vessel approximation. The effect of implant fixation using
sutures was also examined. 5 refs.
USA
Accession no.582162
Item 267Macromolecular Chemistry & Physics
197, No.2, Feb.1996, p.677-86
NOVEL SILICONES FOR TRANSDERMALTHERAPEUTIC SYSTEM. VI. PREPARATIONOF OLIGODIMETHYLSILOXANECONTAINING PYRROLIDONE MOIETY AS ATERMINAL GROUP AND ITS ENHANCINGEFFECT ON TRANSDERMAL DRUGPENETRATIONAoyagi T; Tadenuma R; Nagase Y
Sagami Chemical Research Center
Oligodimethylsiloxanes containing a pyrrolidone
moiety at one chain end were prepared to develop a
silicone-based transdermal penetration enhancer. The
enhancing activity of drug penetration was evaluated
by in vitro experiments using a two-chamber diffusion
cell. Indomethacin and antipyrine were used as model
drugs. 15 refs.
JAPAN
Accession no.580996
Item 268Journal of Biomedical Materials Research
30, No.2, Feb.1996, p.245-50
CONTRIBUTION OF VASCULAR CATHETERMATERIAL TO THE PATHOGENESIS OFINFECTION: DEPLETION OF COMPLEMENTBY SILICONE ELASTOMER IN VITROMarosok R; Washburn R; Indorf A; Solomon D;
Sherertz R
Lentini Medical Center; Wake Forest,University; Akron
Infectious Diseases Inc.; Becton Dickinson
Pharmaceutical Systems
A functional complement opsonisation assay and
radioimmunoassays were used to compare the relative
abilities of silicone, PU and PVC to activate complement.
Serum incubated in silicone catheters for 24 h had less
than 30% of the opsonising ability of fresh serum while
78% or more of the opsonising ability remained with
serum incubated in PU or PVC catheters. Measurement
of C3a des Arg, C4a des Arg, C5a des Arg and SC5b-9
demonstrated that the loss of opsonising ability was due
to 10-fold greater alternate pathway complement
activation by silicone than by PU or PVC. This finding
suggested that excessive complement activation by
silicone could explain the greater inflammation seen
around silicone catheters in vivo and might also play a
role in silicone’s creating a greater risk of infection. 47
refs.
USA
Accession no.580659
Item 269148th ACS Rubber Division Meeting. Fall 1995.
Conference Preprints.
Cleveland, Oh., 17th-20th Oct.1995, Paper 86, pp.12.
012
ADVANCES IN SILICONE RUBBER ENGINEGASKET SEALINGFiedler L D; Hebda T J; Kucinski E M; Lee M H;
Zawadzke J K
Dow Corning Corp.; Dow Corning STI
(ACS,Rubber Div.)
An account is given of tests undertaken by Dow Corning
in the development of silicone rubber compounds for use
in automotive engine gaskets, with particular reference
to the optimisation of compression set resistance,
compression stress relaxation properties and performance
in hot oils.
USA
Accession no.580268
References and Abstracts
120 © Copyright 2001 Rapra Technology Limited
Item 270Polymat ’94 - Polymer Technologies for Electronics.
Conference proceedings.
London, 19th-22nd Sept.1994, p.369-74. 6E
RECENT ADVANCES IN ENCAPSULATION OFMICROELECTRONICS: MATERIALS ANDPROCESSESWong C P
AT & T Bell Laboratories
(Institute of Materials)
Recent advances in polymeric materials and integrated
circuit encapsulants have made high reliability very large
scale integration plastics packaging a reality. High
performance silicone gel possesses excellent electrical
and physical properties for integrated circuit protection.
With their intrinsic low modulus and soft gel-like nature,
silicone gels have become very effective encapsulants
for larger, I/O, wire-bonded and flip-chip VLSI chips.
Integrated circuit technological trends are reviewed,
together with integrated circuit encapsulation materials
and processes. Emphasis is placed on the high
performance silicone gel, epoxies and polyimides, their
chemistry and use as VLSI device encapsulants for single
and multi-chip module applications.10 refs.
USA
Accession no.579676
Item 271Medical Device Technology
7, No.1, Jan/Feb.1996, p.16-8
EVALUATING SILICONE TUBINGHibberd S
Silicone Altimex Ltd.
Concerns associated with the use of silicone tubing in
medical pumping operations are addressed. In particular,
the quantity of extractables that are produced during use
is examined in pumping trials which are performed to
determine the life span of two types of silicone tubing;
platinum cured and peroxide cured. 2 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.579590
Item 272Macplas International
Aug.1995, p.127
SILICONES AND MOULDS
The advantages of using silicone rubber for moulds is
described.
GE SILICONES
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.571210
Item 273Plastics and Rubber Weekly
No.1610, 3rd Nov.1995, p.12
GERMAN MOULDER UPS LSR CONTROL
Woco reports that it is regularly achieving shot weight
standard deviations of less than 0.2% from its Arburg
Allrounder liquid silicone rubber injection moulding
system. In one test, which lasted almost three hours, seal
covers for a car central locking system weighing 5.542g
were produced with a standard deviation of 0.013g. The
Woco machine features Selogica control and a special
15mm screw LSR injection unit. This latter unit is
equipped with a spring-loaded non-return valve which
prevents material from flowing back into the screw,
enabling a high shot weight consistency and a good
surface finish to be achieved even without running a
material cushion.
ARBURG UK LTD.; WOCOEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.568235
Item 274Advanced Materials for Optics & Electronics
5, No.4, July-Aug.1995, p.199-213
COUPLING MONOLAYERS FOR PROTECTIONOF MICROELECTRONIC CIRCUITSFabianowski W; Jaccodine R; Kodnani R; Pearson R;
Smektala P
Lehigh,University
Two polymeric coatings, a silicone gel (Dow Corning
6646) and an epoxy resins (Dexter FP 4402), were glob-
top coated onto representative microelectronic circuits,
AT & T Triple Track Testers(TTTs), and subjected to a
Pressure Cooker Test. Coupling monolayers were self-
assembled on the TTTs prior to encapsulation to improve
the moisture protection capabilities of the coatings.
Leakage current measurements were carried out in order
to evaluate the effect of applied monolayers on the
moisture protection capability. The moisture protection
capability was assessed in short-term and long-term
leakage current measurements. 16-Mercaptohexadecanoic
acid and gamma-aminopropyltriethoxysilane monolayers,
in combination with silicone gel and epoxy resin,
respectively, exhibited very good moisture protection
performance. 29 refs.
DOW CORNING CORP.; DEXTER CORP.; AT & T
BELL LABORATORIESUSA
Accession no.566576
Item 275Nippon Gomu Kyokaishi
67, No.6, 1994, p.411-20
Japanese
PRESSURE-SENSITIVE CONDUCTIVERUBBERS (ROAD SENSORS)
References and Abstracts
© Copyright 2001Rapra Technology Limited 121
Kanamori K
Yokohama Rubber Co.Ltd.
The structure and requirements of silicone-based pressure-
sensitive conductive rubbers are described, particularly
for those used in road sensors for vehicle-sorting systems.
7 refs. Articles from this journal can be requested for
translation by subscribers to the Rapra produced
International Polymer Science and Technology.
JAPAN
Accession no.565957
Item 276Patent Number: US 5412014 A 19950502
FIRE RETARDANT RESIN COMPOSITIONSRomenesko D J
Dow Corning Corp.
A free-flowing silicone polymer powder, which has an
average particle size of 1 to 1000 microns and is prepared
by mixing a polydiorganosiloxane with a silica filler, and
a phosphorus-based fire retardant compound are
uniformly dispersed in an organic resin using conventional
equipment, such as a single screw extruder. The resulting
resin composition shows a significant improvement in fire
retardancy but does not exhibit the severe deterioration
of impact resistance incurred when the resin is modified
with only phosphorus-based fire retardant.
USA
Accession no.564948
Item 277Advanced Materials for Optics & Electronics
4, No.2, March-April 1994, p.95-127
POLYMERIC SILICON-CONTAINING RESISTMATERIALSMiller R D; Wallraff G M
IBM Research Division
A review of silicon-containing bilayer and trilayer
photoresist technology is presented. Multilayer resist
processes of this type are shown to rely on pattern
generation in a thin imaging layer, followed by pattern
transfer to the thick planarising underlayer by oxygen
reactive ion etching. The review concentrates on materials
in which the silicon is an integral part of the polymer and
does not specifically address photoresists where silicon
is incorporated in a post-imaging process step (such as
top-surface-imaging resists). 147 refs.
USA
Accession no.564760
Item 278Journal of Biomedical Materials Research
29, No.10, Oct.1995, p.1179-83
BIOMATERIAL-INDUCED DYSFUNCTION INTHE CAPACITY OF RABBIT ALVEOLARMACROPHAGES TO KILL STAPHYLOCOCCUS
EPIDERMIS RP12Giridhar G; Myrvik Q N; Gristina A G
Medical Sciences Research Institute
The effect of PMMA, titanium alloy, and silicone discs
on the capacity of rabbit alveolar macrophages to kill
RP12 strain of Staphylococcus epidermis was studied in-
vitro. 18 refs.
USA
Accession no.564210
Item 279Journal of Applied Biomaterials
6, No.3, Fall 1995, p.153-60
SELF-REPORTED SIGNS AND SYMPTOMS INBREAST IMPLANT PATIENTS WITH NOVELANTIBODIES TO SILICONE SURFACEASSOCIATED ANTIGENS (ANTI-SSAA(X))Kossovsky N; Gornbein J A; Zeidler M; Stassi J; Chun
G; Papasian N; Nguyen R; Ly K; Rajguru S
California,University
In a pilot study performed several years ago involving
about 350 women, it was observed that a small
subpopulation of silicone breast implants exhibited
antibodies with binding avidities for synthetic
macromolecular complexes of silicone surface charged
adsorbed antigens. These antibodies were unique to breast
implant patients and were not found in either age matchedhealthy patients or rheumatic diseased patients who did
not have silicone implants. The present study was
undertaken to determine if these antibodies might have
any clinical significance and if the model of silicone
surface associated antigens might help rectify the
discrepancy between the various data pools. 60 refs.
USA
Accession no.562154
Item 280Journal of Biomedical Materials Research
29, No.9, Sept. 1995, p.1129-40
AGEING OF SILICONE RUBBERBIOMATERIALS WITH NMRPfleiderer B; Xu P; Ackerman J L; Garrido L
Harvard Medical School; Cincinnati,University
Multinuclear NMR was used to characterise the ageing
process of silicone rubber-based biomaterials after long-
term implantation. The migration of free silicone from
the implants to adjacent tissue was also determined. 35
refs.
USA
Accession no.561605
Item 281Biomaterials
16, No.15, 1995, p.1193-7
INFLUENCE OF DIMENSIONAL STABILITY OF
References and Abstracts
122 © Copyright 2001 Rapra Technology Limited
IMPRESSION MATERIALS ON THEPROBABILITY OF ACCEPTANCE OF APROSTHETIC RESTORATIONPamenius M; Ohlson N G
Karolinska Institute
The accuracy of rubber impression materials was
evaluated by taking impressions of a steel model, pouring
it with stone and comparing certain measurements
between steel and stone models. It is said that acceptance
is achieved when the difference in measurements is within
permissible limits defined by clinical criteria. Data are
given for silicone polymer and polyether impression
materials. 18 refs.
SCANDINAVIA; SWEDEN; WESTERN EUROPE
Accession no.560913
Item 282Injection Molding
3, No.8, Aug.1995, p.66-7
BOTTOM-LINE BENEFITS OF COLD RUNNERLIMKirkland C
Kipe Molds claims that users of the liquid injection
moulding process should weigh the cost and complexity
of cold runner tooling against the cost of non-recyclable
liquid silicone rubber scrap. Cold runner moulds for liquid
silicone rubber can cost two to three times more thanmoulds for conventional runner systems. The elimination
of waste with a costly raw material is likely to provide a
competitive edge. Details are given.
KIPE MOLDS INC.USA
Accession no.560597
Item 283Rubbercon ’95. Conference Preprints.
Gothenburg, 9th-12th May 1995, Paper D1, pp.5. 012
SYNTHETIC VERSUS NATURAL POLYMERS INTHE BIOLOGICAL ENVIRONMENTYannas I V
Massachusetts,Institute of Technology
(Nordic Council of Rubber Technology)
A comparison is made of interactions occurring
between body tissue and synthetic and natural
biomaterials used in implants. It is shown that implants
based on non-degradable polymers such as silicone
rubber induce the synthesis of a fibrous capsule on their
surface, whereas degradable polymers obviate the
formation of a fibrous capsule. Certain natural
polymers, such as highly porous graft copolymers of
type I collagen and chondroitin sulphate (a
glycosaminoglycan), induce the regeneration of
missing tissue rather than the synthesis of scar tissue.
SCANDINAVIA; SWEDEN; USA; WESTERN EUROPE
Accession no.560441
Item 284Design Engineering
July/Aug.1995, p.13
RHEOLOGICAL FLUIDS GIVE BIRTH TOINTELLIGENT SHOCK ABSORBERS
It is reported that the cars of the future may well have
shock absorbers that adapt automatically to road
conditions. Bayer has already made some progress in this
area by carrying out its first tests on shock absorbers with
electrorheological fluids (ERFS). These low-viscosity
‘intelligent fluids’ become highly viscous upon
application of an electrical field. Details are given of the
company’s Rheobay fluid, which is based on a non-
aqueous dispersion of spherical polymer particles in
Baysilone Fluid M, a silicone liquid.
BAYER AGEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.560165
Item 285Patent Number: US 5391336 A 19950221
METHOD FOR FABRICATING FOAM GASKETSAkitomo H; Nozoe T; Shinmi H
Dow Corning Toray Silicone Co.Ltd.
A method for fabricating foam gaskets is characterised in
that during the separate transport and subsequent mixing
in an enclosed chamber of the base and curing agent
portions of a two part foamable and curable organosiloxane
composition an inert gas is injected in an amount of 1-50
ml per 100 g of the total curable organosiloxane
composition. The gas is injected into either the base portion,
the curing agent or during or immediately after mixing of
the two portions, and the resultant foamable composition
is then extruded from a nozzle onto the seal region of the
substrate and cured while foaming.
JAPAN
Accession no.557022
Item 286Journal of Biomedical Materials Research
29, No.7, July 1995, p.849-56
VISCOELASTIC AND ADHERENCEPROPERTIES OF DENTAL RELININGMATERIALSBuch D; Wehbi D; Roques-Carmes C
ENSMM
The viscoelastic properties of acrylic resin, silicone resin
and EVA copolymer dental relining materials were studied
comparatively. Their behaviours were investigated by in
vitro tests that simulate the masticatory cycle. An attempt
was made to correlate the experimental data to the
viscoelastic energy loss observed when instability of the
prosthetic structure occurs. 19 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.555450
References and Abstracts
© Copyright 2001Rapra Technology Limited 123
Item 287Kautchuk und Gummi Kunststoffe
48, No.6, June 1995, p.443-7
UPDATED COMPARISON BETWEEN TOPPERFORMANCE ELASTOMERS INAUTOMOTIVE APPLICATIONSMeyers G
EniChem
Details are given of comparisons between high
performance elastomers used in the automotive industry.
Basic mechanical properties, heat ageing, oil resistance
and low temperature properties are described for NBR,
acrylic rubber, ethylene acrylic rubber, hydrogenated
NBR, chlorosulphonated PE, epichlorohydrin rubber, and
silicone rubber. 5 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.554894
Item 288Patent Number: US 5380478 A 19950110
METHOD FOR PREPARING SILICONE MOULDTOOLINGEast D A
Spraying of high viscosity silicone moulding compositions
is described, together with cured silicone moulds or tools
formed by the process that allow for near perfect transfer
of details from a surface to a moulded object.
USA
Accession no.554039
Item 289Patent Number: US 5376308 A 19941227
COATING SOLUTION FOR FORMINGTRANSPARENT CONDUCTIVE COATING ANDPROCESS FOR PREPARING SAMEHirai T; Komatsu M; Nakashima A; Abe Y; Iwasaki Y
Catalysts & Chemicals Industry Co.Ltd.
A conductive substrate is described, coated with a transparent
conductive coating prepared by dispersion in water and/or
organic solvent of conductive particles having (a) an average
particle diameter of not more than 500 Angstroms, in which
(b) more than 60 wt.% of particles have a diameter of not
more than 600 Angstroms, (c) not more than 5 wt.% of
particles have a particle diameter of not more than 100
Angstroms and (d) not more than 15 wt.% of particles have
a particle diameter of more than 1000 Angstroms. There is a
matrix comprising a silica polymer having an average degree
of polymerisation of 1,500-10,000. The coatings have
excellent adhesion and surface smoothness and also excellent
durability and transparency. Display devices using the
transparent conductive substrates as the display panel have
excellent resolving power, and give constantly clear and
sharp images.
JAPAN
Accession no.553395
Item 290Patent Number: US 5366806 A 19941122
INTEGRATED THERMOPLASTIC RESIN/SILICONE RUBBER ARTICLES AND METHODFOR MAKINGFujiki H; Shudo S
Shin-Etsu Chemical Co.Ltd.
An integrated thermoplastic resin/silicone rubber article
is prepared by modifying a thermoplastic resin with a
silicon-containing compound in monomer or polymer
form, moulding the thermoplastic resin into a shape,
contacting an uncured silicone rubber with the moulded
thermoplastic resin, and curing the silicone rubber at a
temperature below the softening point of the thermoplastic
resin. The article in which the thermoplastic resin is firmly
united with the silicone rubber is useful in electric,
electronic and automotive applications while taking
advantage of the inherent reliability in heat resistance,
weather resistance and electrical properties of the silicone
rubber.
JAPAN
Accession no.552555
Item 291Rubber World
212, No.2, May 1995, p.20/59
AEM - EXTENDED AGEINGS IN SELECTIVEAUTOMOTIVE FLUIDSDobel T M; Kotz D A
DuPont Co.
Changes in the automotive industry are increasing the
demands for higher performance seal and gasket materials
in both the engine and transmission. Moulded rubber
gaskets, carrier gaskets and moulded-in-place
technologies have become the preferred sealing systems.
The vast majority of these newer gasket designs are made
from silicone (VMQ) rubber. The use of ethylene acrylic
elastomers (AEM) in powertrain applications has steadily
increased in recent years, mainly because of their good
balance of high and low temperature properties and oil
resistance. This article compares four AEM polymers,
three of them new grades, with VMQ and polyacrylate.
Extended ageing studies in both engine oil and automatic
transmission fluid are used to demonstrate the merits of
AEM polymers over the long term for powertrain gaskets.
2 refs.
USA
Accession no.552488
Item 292Revue Generale des Caoutchoucs et Plastiques
No.734, Sept.1994, p.68-70
French
SURFACE DEFECTS AND MICROSTRUCTUREOF HEAT CURABLE SILICONE ELASTOMERSVarlet J; Pouchelon A; Bourrain P; Joachim F
References and Abstracts
124 © Copyright 2001 Rapra Technology Limited
Rhone-Poulenc SA
Results are presented of a capillary rheometer study of
the influence of extrusion conditions and rheological
properties on defects occurring on the surface of heat
curable polydimethyl siloxane extrudates. 4 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.552429
Item 293Revista de Plasticos Modernos
68, No.458, Aug.1994, p.173-80
Spanish
DISPERSED ELECTROMAGNETIC SYSTEMS.II. POLYMERS USED IN THEIRMANUFACTURE AND THEIR APPLICATIONSDavidenko N; Orlov D V; Sastre R
Havana,University; Edys; Instituto de Ciencia y
Tecnologia de Polimeros
A survey is made of polymers used in magnetic fluids,
including polysiloxanes and a variety of plastics, and of
a number of uses of these systems, such as hermetic seals,
vibration dampers, lubricants and medical and
pharmaceutical applications. 67 refs.
CUBA; EUROPEAN COMMUNITY; EUROPEAN UNION;
RUSSIA; SPAIN; WESTERN EUROPE
Accession no.552411
Item 294147th Meeting, Spring 1995, Conference Preprints.
Philadelphia, Pa., 2nd-5th May 1995, Paper 57, pp.55.
012
CHARACTERISING RUBBER ELASTICBEHAVIOUR FOR FINITE ELEMENTMODELLINGChouchaoui B; Ulrich E
Gecamex Technologies Inc.
(ACS,Rubber Div.)
Silicone and fluorosilicone rubbers were characterised for
finite element analysis in simple Shore A deformation
modes using as key properties the polynomial and Ogden
strain energy density functions. The influence of material
data on the quality of model representation of automotive
ring gaskets and grommet fasteners was examined. The
predicted force-deflection characteristics satisfactorily
compared to empirical data when proper material models
were selected. Issues such as mesh density, element type
and dimensional tolerances in part geometry were also
studied. 33 refs.
CANADA; USA
Accession no.552390
Item 295147th Meeting, Spring 1995, Conference Preprints.
Philadelphia, Pa., 2nd-5th May 1995, Paper 3, pp.22. 012
USE OF SILICONE RUBBER ON DISCARDINGSABOT PROJECTILESWalker F J
Alliant Techsystems Inc.
(ACS,Rubber Div.)
The application of liquid, high consistency and pumpable
silicone rubbers in gas seals for discarding sabot projectile
assemblies is discussed. An examination is made of the
properties required of such seals, processes used in their
manufacture, and methods for bonding silicone rubber to
steel, aluminium and plastics inserts used in this
application. 7 refs.
USA
Accession no.552346
Item 296Journal of Biomedical Materials Research
29, No.5, May 1995, p.583-90
ASSESSMENT OF VIABILITY ANDPROLIFERATION OF IN-VIVO SILICONE-PRIMED LYMPHOCYTES AFTER IN-VITRORE-EXPOSURE TO SILICONECiapetti G; Granchi D; Stea S; Cenni E; Schiavon P;
Giuliani R; Pizzoferrato A
Bologna,Istituti Ortopedici Rizzoli
The functional response of peripheral blood lymphocytes
isolated from 22 patients with silicone gel-filled breastimplants was assessed after in-vitro re-exposure to
silicone. Using cell culture test methods to quantify
proliferation and viability and/or activation of lymphocyte
microcultures, i.e. the uptake of tritiated thymidine and
the reduction of formazan salts, interesting assay data were
obtained. 18 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.551618
Item 297Journal of Biomaterials Science : Polymer Edition
7, No.2, 1995, p.147-57
REVIEW. RHEUMATIC DISORDERS INPATIENTS WITH SILICONE IMPLANTS: ACRITICAL REVIEWBridges A J
Wisconsin,University; Middleton W.S.,Memorial
Veterans Admin.Hospital
More than 1000 patients with rheumatic disorders and
silicone implants have been reported. The clinical features
of patients with scleroderma, inflammatory myositis,
systemic lupus erythematosus and silicone implants are
discussed. The clinical features of the most common
rheumatic disorder associated with silicone implants, the
‘silicone implant associated syndrome’ are introduced.
In addition, other local regional, and neurological
disorders associated with silicone implants are discussed.
This comprehensive clinical review provides the clinician
References and Abstracts
© Copyright 2001Rapra Technology Limited 125
with information regarding the common symptoms, signs
and laboratory features of rheumatic disorders of patients
with silicone implants. 50 refs.
USA
Accession no.551516
Item 298Journal of Biomaterials Science : Polymer Edition
7, No.2, 1995, p.133-45
SILICONE BREAST IMPLANTS ANDAUTOIMMUNITY: CAUSATION, ASSOCIATION,OR MYTH?Brautbar N; Campbell A; Vojdani A
Southern California,University; Texas,University;
Drew,University of Medicine & Science
In-vivo and in-vitro studies, case reports and population
studies show that (i) silicone is immunogenic, (ii) silicone
is biodegradable and transported via the
reticuloendothelial system to distant locations, (iii)
silicone breast implants leak and in turn silicone migrates
outside the breast tissue, (iv) case reports and population
studies document an autoimmune reaction and
immunological dysfunction in patients with silicone breast
implants, (v) these immunological abnormalities and
symptoms are reversible upon removal of the breast
implants (in 50-70% of cases). The criteria to establish
medical causation are defined, and based on those criteria
it is concluded that silicone breast implants cause
immunological disease. 55 refs.
USA
Accession no.551515
Item 299Journal of Biomaterials Science : Polymer Edition
7, No.2, 1995, p.115-21
REVIEW. DO SILICONE BREAST IMPLANTSCAUSE AUTOIMMUNE RHEUMATICDISEASES?Smith H R
Case Western Reserve University
A spectrum of illnesses ranging from local symptoms to
systemic disease is seen in some patients with silicone
breast implants. However, it remains to be determined
whether such illnesses in these patients are coincidentally
associated or are secondary to the implants. This article
reviews data relating to this issue. 41 refs.
USA
Accession no.551513
Item 300Journal of Biomaterials Science : Polymer Edition
7, No.2, 1995, p.101-13
REVIEW. PHYSICOCHEMICAL ANDIMMUNOLOGICAL BASIS OF SILICONEPATHOPHYSIOLOGY
Kossovsky N; Frieman C J
California,University
Silicones, model biomaterials with almost ubiquitous
applications, are the focus of a contentious debate. In this
review, both established physicochemical phenomena and
immunological phenomena are considered, then the human
clinical phenomena that relate directly to them are
considered. Two competing theories of the biological activity
of silicones are explored, and weaknesses in the various
arguments that silicone is inert are discussed. 91 refs.
USA
Accession no.551512
Item 301Journal of Materials Science.Materials in Medicine
6, No.3, March 1995, p.177-80
SILICONE ELASTOMERS: STUDY OF THEIRMESH SIZE BY THERMAL ANALYSISMoreau J C; Madelmont G; Leclerc B; Mazan J;
Couarraze G
Paris-Sud,Universite
Silicone elastomers are often used as a base for controlled-
release systems for drugs and the modulation of drug
diffusion by varying the mesh size of a silicone elastomer
network has previously been studied. In this work, the
effect of vulcanisation conditions and chemical
modifications on the network mesh size was investigatedby thermal analysis and measurement of swelling ratio.
The influence of these parameters on the diffusion of
model drugs was also studied. 15 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.549399
Item 302Patent Number: EP 640660 A2 19950301
MONITOR PUTTYGibbon R
JMK International Inc.
An apparatus for providing manipulative physical therapy
includes a first mass of a putty including a reaction product
of siloxane with a boron- or tin-containing compound and
a polysiloxane. At least one additional mass of the putty
is provided to the patient, the mass adaptable to be
manually combined by the patient with the first mass until
a uniform colour is achieved. The apparatus provides a
means by which the progress of manipulative physical
therapy may be monitored, as a uniform colour in the
combined mass will be achieved only after extensive
manipulation.
USA
Accession no.545000
Item 303Macplas International
References and Abstracts
126 © Copyright 2001 Rapra Technology Limited
April 1994, p.122-3
LIQUID SILICONE RUBBER FOR HIGHPERFORMANCESchulze M
Bayer AG
Applications of liquid silicone rubbers in injection
moulded components and heat resistant protective
clothing are described. Recycling and other environmental
aspects of these materials are also discussed.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.544318
Item 304Revue Generale des Caoutchoucs et Plastiques
No.729, Feb.1994, p.64-7
French
RUBBER TEATS: MATERIALSDEVELOPMENTS AND REGULATIONSCardinet C; Niepel H
Hutchinson SA; Mapa GmbH
Materials used in teats for baby feeding bottles, including
NR, silicone rubber and styrene-butadiene block copolymer
thermoplastic elastomers are examined, and processes and
additives used in the manufacture of teats are described. A
survey is made of regulations in a number of countries
covering the toxicological characteristics of such materials,
and of test methods used to determine the migration and
extractability of additives and the presence of specific
compounds, with particular reference to nitrosamines. 5 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
GERMANY; WESTERN EUROPE; WORLD
Accession no.544277
Item 305Reinforced Plastics
39, No.3, March 1995, p.16
FAST AND EASY PROTOTYPING OF COMPLEXPARTS
Protomix from Camattini is an easy, cheap and fast tool for
rapid prototyping. The system consists of a vacuum chamber
with a four-way pneumatic injection system controlled by a
pneumatic gun for product mixing and for injection into the
mould, a 24 or 36 element static mixer, twin cartridges
containing the different Protomix PU products designed to
ensure consistent prototyping, and a transparent silicone
rubber which has a high degree of dimensional stability and
low shrinkage for mould production.
CAMATTINI SPAEUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.544136
Item 306Urethane Plastics and Products
25, No.1, Jan.1995, p.1-2
ROGERS CORPORATION SPOTLIGHTS HIGHPERFORMANCE ELASTOMER MATERIALSAND COMPONENTS
Properties and applications of two high performance
elastomer materials from Rogers Corp. are discussed in
some detail. Poron cellular urethane and silicone materials
are reported to be used for products such as gaskets for
disc drives, vibration isolators in machinery, and airbag
detonator protection devices. The company’s Endur range
of elastomeric materials are said to be used in applications
such as components for document handling in office
equipment and extended component life is now reported
to be offered by the new polyisoprene version of Endur
products.
ROGERS CORP.,PORON MATERIALS DIV.USA
Accession no.542377
Item 307Antec ’94. Conference Proceedings.
San Francisco, Ca., 1st-5th May 1994, Vol.I, p.894-6.
012
DETERMINING MOULD FILLING ANALYSISACCURACY FOR THERMOSET MATERIALMutkus E A
Pennsylvania,State University
(SPE)
Pressures predicted by mould filling analysis software
for the moulding of silicone rubber were compared with
results from the actual moulding process. The predictions
were within 10% of the actual process pressures.
USA
Accession no.541223
Item 308Journal of Biomedical Materials Research
29, No.1, Jan.1995, p.59-63
KINETIC STUDY OF RELEASE OF SILICONCOMPOUNDS FROM POLYSILOXANE TISSUEEXPANDERSRaimondi M L; Sassara C; Bellobono I R; Matturri L
Milan,University
The release behaviour of commercial tissue expanders
was examined by the determination of the chemical nature
and its modification after in vivo use by ESCA, and a
kinetic examination of silicon compounds released by the
biomaterial in physiological saline. The correlation of
kinetic and physicochemical tests with the in vivo
behaviour is discussed. 9 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.538596
Item 309Antec ’94. Conference Proceedings.
References and Abstracts
© Copyright 2001Rapra Technology Limited 127
San Francisco, Ca., 1st-5th May 1994, Vol.I, p.234-8.
012
DEVOLATILISATION OF PDMS GUMS: APERFORMANCE COMPARISON OF CO- ANDCOUNTER-ROTATING TWIN-SCREWEXTRUDERSPowell K G
General Electric Co.,Corporate R & D
(SPE)
A study was made of the performance of a co-rotating
twin-screw extruder and a non-intermeshing counter-
rotating twin-screw extruder in the devolatilisation of
polydimethyl siloxane gums. Hydrodynamic differences
between the extruders were reflected in their
devolatilisation performance as a function of operating
parameters. The concept of normalised residuals based
on Latinen’s wiped film model was a useful method for
classifying devolatilisation problems and simplifying
process optimisation. 11 refs.
USA
Accession no.537964
Item 310Antec ’94. Conference Proceedings.
San Francisco, Ca., 1st-5th May 1994, Vol.I, p.94-9.
012
USE OF DIE MODELLING TO IMPROVE THEMANUFACTURING PROCESS FOR EXTRUDEDSILICONE RUBBERReese C; Marchal T; Marchal J M
Dow Corning Corp.; Polyflow SA
(SPE)
Flow analysis software was used to develop a die and
process parameters for the extrusion of complex three-
hole silicone rubber tubing. The resulting modified die
mandrel gave satisfactory match-up of extrudate shape
to the desired shape, increased product quality and
production rate and reduced set-up time. 3 refs.
BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION;
USA; WESTERN EUROPE
Accession no.537941
Item 311Plastiques Flash
No.273, July/Aug.1994, p.40-2
French
LIQUID SILICONES TODAY
The properties, processing and applications of liquid
silicone rubbers are reviewed.
BAYER AG; DOW CORNING CORP.; WACKER-
CHEMIE GMBH; RHONE-POULENC SA;
BEUCHAT G.; M2SEUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
GERMANY; USA; WESTERN EUROPE
Accession no.537919
Item 312Revista de Plasticos Modernos
68, No.457, July 1994, p.22-9
Spanish
SYNTHESIS AND STUDY OF THE OPTICALAND ELECTRONIC PROPERTIES OFPOLYSILANES. II.Peinado C; Catalina F; Schnabel W
Instituto de Ciencia y Tecnologia de Polimeros; Hahn-
Meitner-Institut Berlin GmbH
An examination is made of the electronic transport and
non-linear optical properties of polysilanes. Uses of these
polymers as photoinitiators in polymerisation processes
and precursors for silicon carbide and in microlithography,
charge transport, photoconduction and non-linear optical
applications are described. 26 refs. (Part I: Ibid., 67,
No.456, June 1994, p.567-76).
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
SPAIN; WESTERN EUROPE
Accession no.537904
Item 313Industria della Gomma
38, Nos.7/8, July/Aug.1994, p.42-3
Italian
SILICONE RUBBERS FOR THE TREATMENTOF FABRICSMuller J
Wacker-Chemie GmbH
Applications of silicone rubbers in the coating of fabrics
for use in cable insulation, conveyor belting, protective
clothing and automotive air bags are examined. The
Elastosil range of silicone rubbers produced by Wacker-
Chemie is briefly described.
SILMIX SPA
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
ITALY; WESTERN EUROPE
Accession no.537903
Item 314Polymer Degradation and Stability
46, No.2, 1994, p.241-6
STABILITY OF FIVE PLASTICS USED INMEDICAL DEVICES TO OXIDATIONPRODUCED BY COPPER OR IRON IONS ANDREDUCING AGENTSSagripanti J-L; Hughes-Dillon M K
US,Food & Drug Administration
Polyurethane, silicone rubber, polyamide, PVC, and PE
were exposed to metal-based formulations containing
copper ions or iron ions. Oxidation effects are discussed.
17 refs.
USA
Accession no.537488
References and Abstracts
128 © Copyright 2001 Rapra Technology Limited
Item 315Journal of Biomedical Materials Research
28, No.12, Dec.1994, p.1433-8
SPLENIC RESPONSE TO SILICON DRAINMATERIAL FOLLOWING INTRAPERITONEALIMPLANTATIONGuo W; Willen R; Liu X; Odelius R; Carlen B
Lund,University
Silicone rubber drain fragments were implanted
intraperitoneally to study the splenic response. Four days
after implantation samples of spleen and implanted rubber
fragments were retrieved and studied by SEM and energy
dispersive X-ray microanalysis. 7 refs.
SCANDINAVIA; SWEDEN; WESTERN EUROPE
Accession no.536611
Item 316Polymers for Advanced Technologies
5, No.9, Sept.1994, p.473-8
CYCLIC POLYMERS: PAST, PRESENT ANDFUTURESemlyen J A; Wood B R; Hodge P
York,University; Manchester,University
Methods for characterising cyclic polymers are illustrated
by reference first to dilute solution methods for cyclic
polydimethylsiloxane (PDMS) and then to the entrapment
of cyclic polymers in networks. Preparative routes to
cyclic polymers are reviewed, including ring-chain
equilibration reactions, coupling and condensation
reactions and new methods using polymer-supported
reagents. Some of the properties of PDMS are discussed,
including differences between ring and chain polymer
properties such as their melt viscosities and Tgs. Methods
for preparing the first polymeric catenanes are described,
using polymer-supported reagents. Further directions for
cyclic polymer chemistry are indicated, including
topological polymer chemistry. 43 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.535233
Item 317Journal of Advanced Materials
26, No.1, Oct.1994, p.2-8
MOULDING OF COMPLEX COMPOSITE PARTSUTILISING MODIFIED SILICONE RUBBERTOOLINGWeiser E S; Baucom R M
Georgia,Institute of Technology; US,NASA,Langley
Research Center
Cast silicone rubber was utilised as a tooling aid to apply
pressure to complex composite parts during cure.
Emphasis is given to the governing formula for rubber
expansion and innovative methodology for precise control
of the expansion rate. 6 refs.
USA
Accession no.533922
Item 318Chemistry & Industry
No.17, 5th Sept.1994, p.668
FIRST FOR RAMAN SPECTROSCOPY
The US Armed Forces Institute of Pathology (AFIP)
claims to be the first to use Raman spectroscopy to identify
silicone and other foreign materials in breast tissue. The
article supplies details of a Raman microprobe which
provides a non-destructive technique for examining tissue
on a molecular level. The article includes brief details of
three different types of breast implants analysed using
Raman spectroscopy.
US,FOOD & DRUG ADMINISTRATION;
US,ARMED FORCES INSTITUTE OF PATHOLOGYUSA
Accession no.533709
Item 319Plastics and Rubber Weekly
No.1560, 4th Nov.1994, p.7
RUBBER FLIES SKY HIGH
RE Components has developed a new silicone rubber
compound for cable support bushes for the new V2500
turbofan aircraft engine. The bushes hold wiring in place
in harnesses positioned from near the centre of the engine
to the intake fan. The components had to meet a
specification set by the National Society of British
Aerospace Companies for tolerance of extremes of
temperature. Northern Rubber and British Aerospace
have cooperated to produce an improved thermally
insulated air ducting system for Eurofighter 2000
aeroplanes. The silicone rubber hose system helps keep
equipment cooling air and cockpit air conditioning air
at the right temperature. The insulation material is a
sound-absorbing, flame-retardant PU foam with a tough
film coating.
RE COMPONENTS LTD.; NORTHERN RUBBER
CO.LTD.EUROPEAN COMMUNITY; EUROPEAN UNION; UK;
WESTERN EUROPE
Accession no.533621
Item 320Kunststoff Journal
28, No.3, June 1994, p.44
German
RAPID PROTOTYPES
The MCP vacuum casting method is an effective and
relatively cheap way of producing plastic prototypes and
small batches. A casting mould is made of silicon and
References and Abstracts
© Copyright 2001Rapra Technology Limited 129
casting resin added in a vacuum casting machine and then
cured in a heating chamber.
HEK GMBHEUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.532992
Item 321Plastverarbeiter
45, No.10, Oct.1994, p.26
German
IN-SITU SEALS FOR ENGINE CONSTRUCTION
Using a two-component metering unit, it is possible to
extrude silicon seals directly onto components, e.g. rocker
arm covers, for automobile engine construction.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.532968
Item 322Rubber and Plastics News
24, No.4, 19th Sept.1994, p.6
IMPLANT MAKERS OK 4.25 US BILLIONDOLLAR SETTLEMENTMoore M
The lawsuits taken out against manufacturers of silicone
gel breast implants concern over 90,000 women who have
entered a pact which promises them reimbursement of
between 105,000 and 1.4 million US dollars each over
the next 30 years. Dow Corning and Bristol-Meyers
Squibb Co. affirmed their commitment to the agreement
and the deadline date of 9th September for withdrawal
from the agreement, passed without a defendant company
giving official notice of withdrawal, it is reported.
DOW CORNING CORP.; BRISTOL-MEYERS
SQUIBB CO.USA
Accession no.531787
Item 323Rubber and Plastics News
24, No.3, 12th Sept.1994, p.3
LAWSUITS CLAIM NORPLANT DIFFICULT TOREMOVEMoore M
According to the lawsuit filed recently against Wyeth-
Ayerst Laboratories, their product, a contraceptive system
of implanted capsules tradenamed Norplant, cannot be
removed without extreme pain and permanent scarring
in some cases. The article supplies brief details of the
capsules, made from a patented siloxane polymer, and
the lawsuit.
WYETH-AYERST LABORATORIESUSA
Accession no.531296
Item 324Philadelphia, Pa, 1993. 1/11/93. 6J22
ASTM C 1115-. SPECIFICATION FOR DENSEELASTOMERIC SILICONE RUBBER GASKETSAND ACCESSORIESAmerican Society for Testing & Materials
ASTM C 1115-
Details are given of elastomeric silicone rubber for gaskets
and accessories for use in glazing and sealing applications.
Photocopies and loans of this document are not available
from Rapra. It may be purchased from BSI. Please contact
Rapra for further details.
USA
Accession no.530179
Item 325Antec ’93. Conference Proceedings.
New Orleans, La., 9th-13th May 1993, Vol.III, p.2988-
90. 012
NEW ARTIFICIAL SKIN FACE MASK FORMEASUREMENT OF LACERATIONPOTENTIALMcKinney R; Moody D
Triangle Research & Development Corp.
(SPE)
An account is given of the development of an artificial
skin face mask for dummies used in the measurement offacial laceration potential in trauma and injury research
and automotive component testing. Masks were injection
moulded in PU and silicone polymer compounds, and tests
indicated that a modified two-component silicone had the
best potential for this application. Experiments showed
that such masks could provide approximately the same
laceration index score as double-layer chamois whilst
minimising changes in the dynamic impact response of
the dummy. 7 refs.
APM INC.; BIRMINGHAM,UNIVERSITY;
RENAULT SAEUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; UK;
USA; WESTERN EUROPE
Accession no.528840
Item 326Antec ’93. Conference Proceedings.
New Orleans, La., 9th-13th May 1993, Vol.III, p.2280-
7. 012
PRECISION MOULDING WITH THETIEBARLESS INJECTION MOULDINGMACHINEStrohmaier F
Engel Canada Inc.
(SPE)
Technical features and advantages of tiebarless injection
moulding machines are described, and reference is made
to their use in the flashless moulding of liquid silicone
rubber parts.
References and Abstracts
130 © Copyright 2001 Rapra Technology Limited
CANADA; USA
Accession no.524607
Item 327Adhasion Kleben & Dichten
38, No.4, 1994, p.26-7
German
SEALS EXTRUDED NOT INSERTED
The 2K machine extrudes a silicone-based sealing
material directly where required, instead of an O-ring
being inserted by hand. Measuring and extruding takes a
total of 3 seconds. 300,000 engine gear casings have been
sealed in this way for Peugeot with a failure rate of zero.
Technical details of the robot are given.
PEUGEOT SAEUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.522700
Item 328International Polymer Science and Technology
21, No.4, 1994, p.T/26-37
SYNTHESIS OF SILICONE POLYMERSInoue H
Methods of synthesising silicone polymers with
polysiloxane chains are reviewed in detail, particularly
hydrolytic condensation of chlorosilanes, ring-opening
polymerisation of cyclic siloxanes, synthesis of silicones
by step-growth reaction (condensation), synthesis of
telechelic silicone oligomers by equilibrium
polymerisation, synthesis of modified silicones by
addition reaction, crosslinking of silicones, and the
synthesis of silicone modified polymers with siloxane
polymer chains or side chains. 112 refs. Translation of
Nippon Gomu Kyokaishi, No.9, 1993, p.660
JAPAN
Accession no.522631
Item 329European Plastics News
21, No.7, July/Aug.1994, p.20
PROTECTING ELECTRONIC CHIPSGuyot H
Most of the discrete semiconductors and integrated
circuits in use today are based on silicon and rely on some
form of resin encapsulation to ensure reliable operation
in real-world environmental conditions. Epoxy
compounds dominate with silicones also being used in
considerable volumes. Transfer moulding dominates the
encapsulation business, with multi-plunger moulding
restricted to use with small sized devices. For the new
types of products based on large chips, chip makers have
been forced to return to single piston injection systems
using materials with gel times in excess of 25 seconds. In
the search for low shrink, high throughput resins, a
solution has been found with interpenetrating network
materials based on epoxy and silicone compounds.
WORLD
Accession no.522109
Item 330Rubber and Plastics News
23, No.23, 20th June 1994, p.10
JAMAK WRAPS OFFER RELIEVING HEATMiller J
Jamak Fabrication is reported to have introduced Red-E-
Heat, a new range of therapeutical wraps containing a
microwavable silicone compound. The products are
designed to deliver moist heat therapy and orthopaedic
support to arthritis and muscle pain sufferers, the JMK
International subsidiary claims. Details are given.
JAMAK FABRICATION INC.; JMK
INTERNATIONAL INC.USA
Accession no.521390
Item 331Antec ’93. Conference Proceedings.
New Orleans, La., 9th-13th May 1993, Vol.II, p.2034-6.
012
SILICONE RUBBER MOULDING: THE WHATAND WHYDekker C K
Met-L-Flo Inc.,Plas-T-Flo Div.
(SPE)
The use of silicone rubber moulds for casting PU and
epoxy resins is discussed. Aspects of mould making and
design and factors affecting mould life are examined.
USA
Accession no.520557
Item 332Berlin, 1992. 1/11/92. 6E1
RUBBER INSULATED CABLES, WIRES ANDFLEXIBLE CORDS FOR POWERINSTALLATION - UNBRAIDED HEAT-RESISTANT SILICONE RUBBER INSULATEDCABLESVerband Deutscher Elektrotechniker
VDE 0282(PT506)
Photocopies and loans of this document are not available
from Rapra. It may be purchased from BSI. Please contact
Rapra for further details.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.520334
Item 333Tokyo, 1993. 1/3/93. 45C
References and Abstracts
© Copyright 2001Rapra Technology Limited 131
TESTING METHOD FOR ELECTRICALSILICONE RUBBER COMPOUNDSJapanese Standards
JIS-C2123
Photocopies and loans of this document are not available
from Rapra. It may be purchased from BSI. Please contact
Rapra for further details.
JAPAN
Accession no.520220
Item 334Philadelphia, Pa, 1992. 11/9/92. 6E1
WIRE, ELECTRICAL, SILICONE RUBBERINSULATED, 150 DEG. C, 1000 VOLTS, GLASSBRAID COVERING, ABRASION RESISTANTUS,Navy
MIL-W-16878/31
Photocopies and loans of this document are not available
from Rapra. It may be purchased from BSI. Please contact
Rapra for further details.
USA
Accession no.518409
Item 335Philadelphia, Pa, 1993. 10/2/93. 6H1
HOSE AND HOSE ASSEMBLIES, NONMETALLIC, SILICONE, POLYESTER ANDWIRE REINFORCED (FOR COOLANT ANDHEATING SYSTEMS OF DIESEL & GASOLINEPOWERED ENGINES)US,Navy
MIL-H-62217
Details are given of four types of polyester and wire
reinforced, silicone compounded, elastomeric hose, for
use in coolant and heating systems of diesel and gasoline
engines. Photocopies and loans of this document are not
available from Rapra. It may be purchased from BSI.
Please contact Rapra for further details.
USA
Accession no.518372
Item 336European Rubber Journal
176, No.5, May 1994, p.24-5
EMI SHIELDING: A SILVER LINING?
Dunlop Precision Rubber and James Walker & Co. have
both recently introduced new ranges of high performance
conductive elastomers for EMI shielding seals, primarily
needed in aerospace and defence applications. Dunlop
Precision’s range is based on silicones and fluorosilicones,
with metallic or metal-coated fillers. Materials used as
fillers include hollow glass spheres coated with metal,
which gives low weight, and metallised fabric. James
Walker claims its range of conductive elastomers, using
silver-coated glass spheres, give the highest performance
for cost of any conductive elastomer and will cut the cost
of EMI shielding. The company’s Shieldseal 105 material
is an alternative to heavier, more expensive conductive
elastomers originally designed for military uses, it claims.
DUNLOP LTD.,PRECISION RUBBERS DIV.;
WALKER J.,& CO.LTD.EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.512684
Item 337New Scientist
142, No.1923, 30th April 1994, p.21
POLYMER PUTTY MAKES FOR SAFERTUMOUR TREATMENTBeard J
A polymer putty has been developed which will be of use
in shielding healthy tissue from the effects of radiation
used to treat oral tumours. The putty is made from 90-
95% metal powder bound together by polysiloxane. The
putty can easily be shaped around irregular shaped
tumours and also skin melanomas. Further details are
given.
AMERICAN DENTAL ASSOCIATION HEALTH
FOUNDATION; US,NATIONAL INST.OF
STANDARDS & TECHNOLOGYUSA
Accession no.512191
Item 338International Journal of Adhesion & Adhesives
14, No.2, April 1994, p.103-7
HYDROTHERMAL STABILITY OF JOINTS,USING A SILICONE RUBBER ADHESIVE, FOR ARANGE OF ADHERENDS OF INTEREST TOMAKERS OF SURGICALLY-IMPLANTEDMICROELECTRONIC DEVICESDonaldson P E K
London,University College
This paper describes a series of accelerated life tests on
the adhesion between a convenient silicone rubber (Dow
Corning 3140) and a range of adherend materials of which
such structures might be made. It appears that bonding is
by chemisorption and varies in resistance to degradation
in water according to the density of negative charge on
the adherend surface. The work is thought to provide the
beginnings of a rational process for choosing adherend
materials in implant design. 7 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.510798
Item 339Adhesives Age
37, No.4, April 1994, p.16/22
APPLICATIONS OF CURED-IN-PLACE
References and Abstracts
132 © Copyright 2001 Rapra Technology Limited
GASKETING TECHNOLOGYDiNicola D; Ledoux R E
Robotics Inc.
It is reported that for more than two decades, silicone
rubber has been the material of choice in many industries
for making formed-in-place and moulded-in-place gaskets
on products ranging from small appliances to automotive
engines. The most common form of sealant has, until
recent years, been room temperature vulcanisation.
Several case histories are outlined which focus on liquid
silicone rubber materials used to form cured-in-place
gaskets onto a variety of products.
USA
Accession no.509900
Item 340Journal of Biomaterials Science : Polymer Edition
5, No.4, 1994, p.339-51
CONTROLLED RELEASE OF BETA-ESTRADIOL FROM BIODEGRADABLEMICROPARTICLES WITHIN A SILICONEMATRIXBrannon-Peppas L
Biogel Technology
Biodegradable controlled release systems were prepared
from biodegradable microparticles of poly(lactic acid-co-
glycolic acid) containing beta-estradiol in the presenceor absence of silicone. The release behaviour of beta-
estradiol from free microparticles and from microparticles
embedded within a silicone matrix was compared with
the release behaviour shown by non-encapsulated beta-
estradiol within a silicone matrix. It was found that
incorporating biodegradable microparticles within a
silicone matrix lessened the initial burst of release often
seen with these types of formulations and provided a
controlled rate of drug release. In addition, the release
rate of beta-estradiol from biodegradable microparticles
within silicone was higher than for unencapsulated beta-
estradiol in silicone. This type of formulation could be
useful in a number of instances, such as release of drugs
from implants for which a simple drug-silicone
formulation did not yield desired release behaviour,
formulations which are currently developed for
microparticles but which may need to be removed if
necessary and implant formulations containing drugs
which will not diffuse through silicone. 29 refs.
USA
Accession no.508853
Item 341Modern Plastics International
24, No.3, March 1994, p.20/3
LINE BETWEEN PROTOTYPING,PRODUCTION IS BLURRINGInnace J J; Snyder M R
A recent technical push in rapid prototyping technology
is in the area of short production runs that can yield as
many as 100 low-cost parts in a matter of days. General
Pattern Co. has recently developed an in-house process
using RIM equipment. Mox-Med Inc. is specialising in
the custom prototyping and manufacture of silicone rubber
medical components using the liquid injection moulding
process. MCP Systems Inc., a supplier of automatic
vacuum casting machines, has a system employing
silicone moulds. The company says seven or eight finished
PU parts can be produced per day.
GENERAL PATTERN CO.; MOXMED INC.; MCP
SYSTEMS INC.USA
Accession no.507564
Item 342IRC ’93/144th Meeting, Fall 1993. Conference
Proceedings.
Orlando, Fl., 26th-29th Oct.1993, Paper 112, pp.18.
012
INCREASING THE PROFITABILITY OFSILICONE RUBBER MOULDINGTanton R
Dow Corning STI
(ACS,Rubber Div.)
An examination is made of the advantages in terms of
increased productivity and reduced production costs of
using platinum cure systems in place of peroxides in the
moulding of silicone rubber compounds.
USA
Accession no.505684
Item 343Gummibereifung
69, No.7, July 1993, p.54-6
German
SILICONE RUBBER SUCCESSFUL IN SEALINGJOINTS
Silicone rubber, composed of silicon and oxygen rather
than carbon, is discussed as a material for seals on aircraft
windows and on ovens. The advantages are heat
resistance, cold flexibility, good ageing and weathering
resistance, resistance to ozone and radiation, electrical
insulation. Solid and liquid types of silicone rubber are
described. Further applications are listed, e.g. medical
tubing, rollers, electric cables.
EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.505580
Item 344Plastics & Rubber & Composites Processing &
Applications
19, No.2, 1993, p.87-92
References and Abstracts
© Copyright 2001Rapra Technology Limited 133
INJECTION MOULDING OF CUSTOM HIPREPLACEMENT SOCKETSQuek C H; Crawford R J; Orr J F
Belfast,Queen’s University
An investigation is described of the feasibility of injection
moulding hip replacement sockets on a ‘one-off’ basis. A
silicone rubber impression was used to reproduce the
required socket shape in PMMA within a standard mould
backing block. PE was then injected into the mould to
produce good quality mouldings, the PMMA mould
showing little deformation at the moulding temperature
and pressures used. Further process development is
required for the orthopaedic application described but the
process is offered as a means of injection moulding low
numbers of components or for testing prototype mould
designs. 9 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.505507
Item 345Patent Number: WO 9401496 A1 19940120
METHOD AND DEVICE FOR CUSHIONINGLIMBSBracken R L; Winn R A; Riley N L
Schering-Plough Healthcare Products Inc.
A soft, tacky polysiloxane elastomer, which has specified
tackiness, tensile strength, minimum elongation and tearstrength values, is disclosed. The elastomer may be made
into various cushioning devices with or without a top
cover, such as arch support pads, metatarsal pads, heel
cushions, sheet padding, insoles, toe-crest pads, heel
liners, elbow pads, corn and callus pads, blister pads,
bunnion pads and toe pads.
USA
Accession no.505382
Item 346Progress in Organic Coatings
23, No.3, Feb.1994, p.201-36
SYNTHESIS AND APPLICATIONS OFPHOTOCROSSLINKABLE POLYSILOXANESAbdellah L; Boutevin B; Youssef B
Montpellier,University
This survey reviews the synthesis and curing of
polysiloxanes by UV radiation and electron beams. Three
main kinds of products are described: those formed by
an applied radical mechanism and constituting acrylated
polysiloxanes linked by either Si-OC bonds or Si-C bonds,
or by urethane acrylated polysiloxanes or by the thiol-
enes system; those using a cationic mechanism listing the
epoxy grafted polysiloxanes, the vinyl and the styrenic
corresponding compounds; and a special type of
polysiloxane cured by a noble metal or SiH-Si vinyl. In
each case, the mechanism, photosensitisers, additives,
reactive diluents and apparatus for curing formulations
are given. Some applications and properties of these
products, mainly in the field of coating such as release
papers are described. An attempt is made to relate the
structure of these kinds of polydimethylsiloxanes to their
properties. 149 refs.
EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE
Accession no.503975
Item 347Nippon Gomu Kyokaishi
66, No.12, 1993, p.890-4
Japanese
DETERIORATION OF OIL SEALS ANDANALYSISSenda K
NOK Corp.
A discussion is given of the factors such as cracking and
abrasion which affect the service life of oil seals made
from silicone rubbers, and of their investigation by IR
spectroscopy and bench tests. 14 refs. Articles from this
journal can be requested for translation by subscribers to
the Rapra produced International Polymer Science and
Technology.
JAPAN
Accession no.503825
Item 348Plastics and Rubber Asia
8, No.49, Dec.1993, p.41
INJECTION MOULDING SILICON RUBBERSitard F
Dr.Boy GmbH
The processing of liquid silicone rubber is discussed. The
relatively new material is finding acceptance as an
alternative to solid silicone rubbers and other organic
elastomers. Properties of the material are described, in
particular its good ageing resistance, wide temperature
tolerance, and electrical properties. The advantages of its
processability and high temperature vulcanisation are put
to advantage in industrial scale manufacturing of small
flexible mouldings.
EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.501025
Item 349PV International Plastics Magazine
4, No.2, Oct.1993, p.18-9
BACK-FORMING AND LSR PROCESSING INTHE INJECTION MOULDING PROCESS
A new injection moulding machine from Krauss-Maffei
Kunststofftechnik was presented at the company’s in-
house trade fair 1993. The machine is capable of
producing large laminated plastic parts for use, as an
example, in inside panellings of cars, in one single
References and Abstracts
134 © Copyright 2001 Rapra Technology Limited
operation. It is designated KM 800-5700 VIM based on
the vertical injection moulding principle for back-forming
applications. The KM 40-190 C2 injection moulding
machine also presented, is capable of processing liquid
silicone rubber.
KRAUSS-MAFFEI KUNSTSTOFFTECHNIK GMBHEUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.499130
Item 350Biomedical Materials
Nov.1993, p.7-8
COATED BREAST IMPLANTS FOUND TORELEASE POSSIBLE CARCINOGEN
Research carried out by Bristol-Myers Squibb and
supervised by the US Food & Drug Administration is
reported to show that silicone breast implants coated with
PU foam release a suspected carcinogen. The studies
confirm earlier suspicions about the implants, which were
marketed under the names of Meme, Replicon and Natural
Y before suspension of sales in 1991.
BRISTOL-MYERS SQUIBB CO.USA
Accession no.498799
Item 351Nippon Gomu Kyokaishi
66, No.9, 1993, p.660-72
Japanese
SYNTHESIS OF SILICONE POLYMERSInoue H
Osaka Municipal Industrial Research Institute
A review is given of the reactions of formation of silicone
polymers and of the synthesis of silicone-vinyl block
copolymers, silicone-polyester block copolymers,
silicone-polyamide block copolymers, silicone-modified
polyurethane and polyurea, silicone-polycarbonate block
copolymers, silicone-PSF, -PES and -PEEK block
copolymers, silicone graft copolymers, silicone-modified
epoxy resins, silicone IPN and hybrids. 112 refs. Articles
from this journal can be requested for translation by
subscribers to the Rapra produced International Polymer
Science and Technology.
JAPAN
Accession no.498526
Item 352Plastics in Telecommunicatons VI. Conference
Proceedings.
London 16th-18th Sept.1992, p.12/1-12/9. 6E
SYSTEMS FOR SEALING FIRE-RATEDPENETRATIONSRichards J
Dow Corning Hansil Ltd.
(PRI)
Systems which are used to seal penetrations in fire walls
and partitions caused by the passage of cables, pipes and
ducts are described. Silicone foam penetration seals are
included. These systems prevent the spread of flame,
smoke and toxic gases.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.496029
Item 353Revue Generale des Caoutchoucs et Plastiques
70, No.725, Sept.1993, p.71-2
French
LIQUID SILICONE RUBBER: MATERIAL OFTHE FUTURESchulze M
Bayer AG
An examination is made of the vulcanisation, injection
moulding, environmental and quality aspects and
applications of Silopren LSR liquid silicone rubbers,
developed by Bayer AG.
EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.495691
Item 354Advanced Materials
5, No.10, Oct.1993, p.743-6
ELECTROLUMINESCENT DEVICES BASED ONPOLY(METHYLPHENYLSILANE)Suzuki H; Meyer H; Simmerer J; Jiping Yang; Haarer D
Bayreuth,University
The fabrication of high-efficiency light-emitting diodes
(LEDs) based on sublimed molecular films has attracted
much attention in the search for materials for application
in large-area flat-panel displays. Here, multi-layered
LEDs based on poly(methylphenylsilane)(PMPS) as the
hole transporting material are reported. In contrast to
polyphenylenevinylene, PMPS films exhibit a high
effective mobility of holes, making the material suitable
for fast switching applications. 21 refs.
EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.495629
Item 355Plastverarbeiter
44, No.9, 1993, p.96/8
German
EMBOSSING OF DECORATIVE MATERIALSAND LSR PROCESSING IN THE INJECTIONMOULDING PROCESS
At its in-house trade fair in 1993, Krauss-Maffei
Kunststofftechnik is reported to have presented the following
innovations - a new machine concept for production of large
laminated plastics parts, e.g. the inside panellings in cars in
a single operation; and an injection moulding machine for
processing liquid silicone rubber. Details are given.
References and Abstracts
© Copyright 2001Rapra Technology Limited 135
KRAUSS-MAFFEI KUNSTSTOFFTECHNIK GMBHEUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.495503
Item 356Journal of Applied Polymer Science
50, No.4, 20th Oct.1993, p.729-33
SWELLING PROPERTIES OF CROSS-LINKEDMAXILLOFACIAL ELASTOMERSAndreopoulos A G; Polyzois G L; Evangelatou M
Athens,National Technical University;
Athens,University
Silicone (Cosmesil SM4) specimens cross-linked with
various amounts of cross-linking agent were studied in
terms of mechanical and swelling behaviour. The
measured tensile modulus allowed calculation of the
average molecular weight between crosslinks.
Equilibrium swelling data were also used, in combination
with the molecular weight between crosslinks data, to
obtain the interaction parameter of various silicone-
solvent systems at 25C. Swelling was studied also for
silicone samples with varying network densities in
selected solvents such as toluene, ethyl acetate, n-butanol
and methyl ethyl ketone. 17 refs.
EUROPEAN COMMUNITY; GREECE; WESTERN EUROPE
Accession no.494886
Item 357China Synthetic Rubber Industry
16, No.5, Sept.1993, p.268-70
Chinese
PREPARATION AND PROPERTIES OFSILICONE RUBBER DISPERSIONZhao Mingxing; Dai Mengxian; Wu Ping; Tong
Jinquan; Duan Wei
China,Ministry of Chemical Industry
Based on previous works, this study describes the
preparation and stability of silicone rubber dispersion.
Stable homogeneous silicone rubber dispersion could be
made by dissolving reinforced GY-31 medical grade
silicone rubber in 1,1,1-trichloroethane, then pounding
in a high speed mill. Thin-walled silicone rubber articles
with complex shapes prepared from the dispersion by dip-
coating or spraying could satisfy clinical uses. 6 refs.
CHINA
Accession no.494209
Item 358BIBRA Bulletin
32, No.4/5, May/June 1993, p.155
SILICONE MEDICAL DEVICES
The FDA is requiring manufacturers to update information
on immune-related disorders in the informed consent
documents for women receiving breast implants in clinical
studies, it is announced. This follows data obtained from
rat studies which supports a possible link between silicone
gel-filled breast implants and autoimmune disorders.
Further brief details are given.
US,FOOD & DRUG ADMINISTRATION
USA
Accession no.489233
Item 359Plastverarbeiter
44, No.6, June 1993, p.46/50
German
EXTRUSION AND CROSSLINKING OF SOLIDSILICONE RUBBERFuchs P
This review of silicone rubber extrusion examines plant
design and layout, extrusion lines and conditions, mould
engineering, vulcanisation systems and conditions,
ancillary equipment, profile dies and applications.
EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.488323
Item 360International Polymer Processing
8, No.2, June 1993, p.178-81
COMPUTER CONTROLLED ROTATIONALMOULDING OF LIQUID SILICONE POLYMERTeoh S H; Guan K W; Lee N H; Wong Y S; Nee A Y C;
Pho R W H
Singapore,National University
Computers have made it possible to control the thickness
of the object accurately. This was made possible by
creating an intelligent software which takes in the
viscosity and density time variation of the polymer. Using
the flat plate withdrawal theory, it computes the new speed
for each axis. The relationship between rotational
moulding parameters and polymeric material properties
for a solvent-silicone rubber system is demonstrated using
a hand prosthesis as an example. The time required for
gelation of the silicone rubber was about 2 hours. 8 refs.
SINGAPORE
Accession no.486519
Item 361Journal of Biomedical Materials Research
27, No.7, July 1993, p.867-75
POROUS COLLAGEN SPONGE FOROESOPHAGEAL REPLACEMENTNatsume T; Ike O; Okada T; Takimoto N; Shimizu Y;
Ikada Y
Kyoto,University
A new artificial oesophagus with a bilayered structure
made of porous collagen sponge and silicone was studied.
Microscopic observation of tissue reconstruction and
epithelial regeneration are presented. 41 refs.
References and Abstracts
136 © Copyright 2001 Rapra Technology Limited
JAPAN
Accession no.484268
Item 362Fire & Flammability Bulletin
June 1993, p.7
SILICONE RUBBER DEVELOPMENT PASSESTOUGH SAFETY TESTS
Silicone Altimex has developed a low toxicity/low smoke
silicone rubber, which will have potential for rubber
sealing componentry in the building and transportation
markets. The article supplies details of several stringent
and comprehensive fire and smoke tests passed by the
material. Likely applications include window and door
seals in buildings and transportation.
SILICONE ALTIMEXEUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.484121
Item 363Revue Generale des Caoutchoucs et Plastiques
70, No.720, Feb.1993, p.58-64
French
APPLICATIONS OF SILICONE RUBBERSSchorsch G
Rhone-Poulenc SA
The structure, properties and applications of
polydimethylsiloxane elastomers are examined. 3 refs.
EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE
Accession no.483624
Item 364Plastverarbeiter
43, No.11, Nov.1992, p.183-5
German
AT K ’92: LIQUID SILICONE RUBBER. A HIGH-PERFORMANCE MATERIAL FOR THEFUTURE
This paper is based on an address given by Dr M. Schulze
of Bayer AG. Liquid silicone rubber is the only type of
crosslinkable rubber that can be processed in liquid form.
Bayer supplies this material as Silopren LSR, a ready-to-
use, two-component liquid silicone rubber for the injection
moulding of small flexible parts and the coating of textile
fabrics.
BAYER AGEUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.480540
Item 365Adhesives Age
36, No.5, May 1993, p.26-31
ISO CLASSIFICATION AND REQUIREMENTSTANDARD FOR FACADE AND GLAZINGJOINT SEALANTS. PART II.
Wolf A T
Dow Corning Corp.
This detailed article evaluates ten commercially available
silicone construction sealants according to the draft
standard of ISO/DIS 11600. Information presented
includes an overall assessment summary. The study
concludes that ISO/DIS 11600 can be regarded as a step
towards international harmonisation of the standards
required within the sealant industry. (This article is the
second part of an article dealing with ISO Classification
and Requirement Standard for Facade and Glazing Joint
Sealants; part one of the article appears in Adhesives Age,
April 1993). 5 refs.
USA
Accession no.480387
Item 366Biomaterials
14, No.6, May 1993, p.459-64
BIODETERIORATION OF MEDICAL-GRADESILICONE RUBBER USED FOR VOICEPROSTHESES: A SEM STUDYNeu T R; Van der Mei H C; Busscher H J; Dijk F;
Verkerke G J
Groningen,University; Netherlands,Biomedical
Technology Centre
Silicone voice prostheses used for rehabilitation of speechafter total laryngectomy are inserted in a non-sterile
habitat. Deposits on explanted Groningen Button voice
prostheses revealed a biofilm, the result of colonisation
of the silicone surface by bacteria and yeasts. Furthermore,
it was shown by SEM on sectioned explants that the
silicone material was degraded by filamentous and
vegetative yeast cells. The different explants showed a
variety of sharp-edged, discrete yeast colonies. The yeasts
grew just under the silicone surface and up to 700 microns
into the silicone material. Nine different types of defect
in the silicone material created by the yeasts are described.
This degradation of the silicone by yeasts appeared to be
the main cause of failure and of the need for frequent
replacement of the prostheses. 10 refs.
EUROPEAN COMMUNITY; NETHERLANDS; WESTERN
EUROPE
Accession no.478732
Item 367Rubber World
207, No.6, March 1993, p.17/22
SILICONE MAKING AUTOS QUIETER THANEVERFinney D L
GE Silicones
Automotive engineers are constantly looking for materials
that serve to dampen vibration and hence reduce noise.
Silicones have found numerous automotive applications
where noise is concerned. Silicone gaskets and bushings
References and Abstracts
© Copyright 2001Rapra Technology Limited 137
help to reduce noise within the engine, including noise
produced by timing chain mechanisms, valves and other
enclosed moving engine parts. General Motors’ new
Northstar engine incorporates special silicone gaskets to
help reduce noise produced by the air and fuel delivery
systems. Chrysler is using a special silicone coating
system, developed by GE Silicones, as a coating on EPDM
weather stripping for windows and doors.
USA
Accession no.476856
Item 368Chemical Marketing Reporter
243, No.17, 26th April 1993, p.SR34
NEW MARKETSCintron I
GE Silicones reports that although growth in Western
Europe and the US has slowed, the company has seen
double-digit growth for its silicone rubber line in the Asia
Pacific region. Overall the US domestic silicones market
is estimated at over 300 million pounds, serving the three
principal end use sectors of fluids, elastomers and resins.
Dow Corning, with a 45% share of the US market, is to
double capacity at its plant in Barry, Wales, and has
invested in research facilities at its headquarters in
Midland, Mich. and Yamakita, Japan. GE Silicones has a
new applications development centre in Oyama, Japan.
Union Carbide has announced it has finally found a buyer
for its silanes business.
WORLD
Accession no.476623
Item 369Multiple Shot, Insert, and Co-Injection Molding.
Conference Proceedings.
Northbrook, Il., 23rd-24th Oct.1991, p.129-40. 83
INSERT MOULDING WITH SILICONE RUBBERMiller M
Lucas Duralith Corp.
(SPE,Chicago Section; SPE,Milwaukee Section)
This article describes the insert moulding of silicone
rubber keypads produced at Lucas Duralith using the
liquid injection moulding process. Information is
presented on two types of keypad design - diaphragm or
pusher-pad - which are used for a majority of the
company’s products. The use of the compression process
is also briefly mentioned, although the company is said
to only use this process for the moulding of silicone rubber
stock which is then used to produce conductive ‘pills’ or
contacts.
USA
Accession no.473906
Item 370Biomaterials
14,No.3,1993,p.184-8
IN VITRO ASSESSMENT OF BACTERIALADHESION TO HYDROMER-COATEDCEREBROSPINAL FLUID SHUNTSBridgett M J; Davies M J; Denyer S P; Eldridge P R
Nottingham,University; Brighton,University;
Nottingham,Queens Medical Centre
The adherence of five strains of Staphylococcus epidermis
and one strain of S.aureus to both untreated and
Hydromer-coated silicone rubber cerebrospinal fluid
shunts was studied in vitro using epifluorescent image
analysis. The potential of the Hydromer coating in creating
biomaterial surfaces which reduce the initial adhesion of
bacteria is demonstrated, with a view to reducing the
incidence of biomaterial-related infections. The
importance of uniformity of coating along the lumen of
cerebrospinal fluid shunts is highlighted. 14 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.472417
Item 371International Polymer Science and Technology
19,No.11,1993,p.T/9-11
NON-HALOGEN-CONTAINING ELASTOMERCOMPOSITES OF LOW COMBUSTIBILITYMerkulova T A; Voloshin V N; Mikhlin V E; Kozlova
G S
It was confirmed that vulcanisates of siloxane polymers
with phenyl substituents at the silicon atom are more flame
resistant than polymers containing vinyl and methyl
substituents. A dependence of the time of extinguishment
of specimens on the composition and structure was
established. Compositions developed with increased
flame propagation resistance, based on SKEP (EPM) and
SKEPT (EPDM) and containing aluminium hydroxide,
are recommended for introduction in the production of
cables for ships, shafts and underground railways. 4
refs.Translation of Kauch.i Rezina,No.3,1992,p.10
RUSSIA
Accession no.472378
Item 372Advances in Pressure Sensitive Adhesive Technology
1.
Warwick,RI,1992,p.50-76. 6A1
CHEMISTRY AND TECHNOLOGY OFRADIATION CURABLE SILICONE RELEASECOATINGSEckberg R P
General Electric Co.,Silicones Div.
Edited by: Satas D
(Satas & Associates)
A brief discussion is presented on the UV- and electron
beam curing of silicone release agents followed by an
overview of radiation curable silicones. These silicones
References and Abstracts
138 © Copyright 2001 Rapra Technology Limited
include acrylated silicones, mercapto-vinyl silicone
systems and cationic radiation curable silicones. Mention
is also made of controlled release additives for silicone
systems. 49 refs.
USA
Accession no.469337
Item 373Materials News International
No.39,1993,p.8-9
BRINGING RELIEF TO OVER ONE MILLIONPEOPLESwanson A B
Dow Corning Europe SA
Replacement joint implants are described which are made
of three grades of Silastic elastomers, and which are used
in the treatment of arthritis.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.469318
Item 374Plastics and Rubber Weekly
No.1469,23rd Jan.1993,p.9
THERMOSETS RESTRICTED TO NICHEMARKETS IN THE FUTURE
Krauss Maffei has developed a two component injection
moulding machine to mould polyester BMC valve covers
with integral seals in LSR. KM has developed its new
modular machine concept to assist thermoset processors.
To change from thermoplastics to thermosets moulding
simply involves changing the injection unit and the cards
in the control system. A new machine concept was
developed and this was based upon three stages of
processing. These were the optimised processing of BMC
and LSR and the use of a turntable mould. The KM
patented AZ unit provides fully automatic material supply.
KRAUSS-MAFFEI (UK) LTD.EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.468591
Item 375Polimery Tworzywa Wielkoczasteczkowe
37,No.11-12,1992,p.504-7
Polish
UTILISING THE DAMPINGCHARACTERISTICS OF SILICONE POLYMERSIN SHOCK-ABSORBING STRUCTURES ANDTECHNOLOGYMaciejewski J
Warsaw,Industrial Chemistry Research Institute
The damping characteristics of Polastosil ABM, a range
of siloxane polymers used in shock-absorbing materials,
and their main useful properties and potential applications
are discussed. The design and the static and dynamic
characteristics of a railway buffer constructed using this
type of material, as well as results from the author’s own
studies on the use of Polastosil in the construction of car
suspensions, are also presented.Articles from this journal
can be requested for translation by subscribers to the Rapra
produced International Polymer Science and Technology.
EASTERN EUROPE; POLAND
Accession no.467735
Item 376Polimery Tworzywa Wielkoczasteczkowe
37,No.11-12,1992,p.499-503
Polish
SILICONES AS MATERIALS WITH A FUTUREIN POLANDRosciszewski P; Zielecka M
Warsaw,Industrial Chemistry Research Institute
A brief review is presented, with reference to published
papers and patents, of the history and results of research
at the Zoliborz Chemical Institute in the field of synthesis,
processing and applications of various organosilicon
monomers and polymers. The main commercially
developed manufacturing processes and the development
of production and application of silicones in Poland are
discussed. A table listing the tested and currently
manufactured products with their names is given. It is
pointed out that there is a considerable delay in the
consumption of silicones in Poland in terms of quantity
and range as compared with the industrially developed
countries. 94 refs.Articles from this journal can be
requested for translation by subscribers to the Rapra
produced International Polymer Science and Technology.
EASTERN EUROPE; POLAND
Accession no.467734
Item 377Paper, Film & Foil Converter
66,No.10,Oct.1992,p.74/8
SILICONE TECHNOLOGY TAPS PSA MARKETOPPORTUNITIESHandt C M; Kelly D T
The use of silicone technology in pressure-sensitive
applications is discussed in detail, with special reference
to difficult environments, e.g. when adhesives must resist
moisture, chemicals and extreme temperatures.
DOW CORNING CORP.USA
Accession no.467294
Item 378PV International Plastics Magazine
Oct.1992,p.82/5
HIGH-PERFORMANCE MATERIAL FOR THEFUTURE
The production and application of Bayer’s Silopren LSR,
is described. The two-component, liquid silicone rubber
References and Abstracts
© Copyright 2001Rapra Technology Limited 139
is suitable for injection moulding small parts and coating
textile fabrics. Applications include protective clothing,
electronic applications, automotive applications, medical
applications and many others.
BAYER AGEUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE
Accession no.467145
Item 379Macplas International
May 1992,p.92-3
FAST CURING FOR OPTICAL FIBRESDennis W E; Burke D W
Dow Corning Corp.
The use of UV cured silicone polymers in optic fibre
coatings is examined, and advantages over heat cured
silicone polymer and UV cured acrylic polymer coatings
are described.
USA
Accession no.466464
Item 380Revue Generale des Caoutchoucs et Plastiques
69,No.715,June/July 1992,p.58-62
French
SILICONE TECHNOLOGY IN THE SERVICE OFELECTRONICSGensler G
GE Silicones
An examination is made of the thermal and dielectric
properties, heat resistance and weathering characteristics
of silicone rubbers for use in electronic applications,
including coatings, potting compounds, adhesives and
transfer moulded components.
USA
Accession no.466444
Item 381Materials Engineering
109,No.9,Sept.1992,p.21-2
SILICONE FOAMS LIGHTEN UPHartley K R
GE Silicones
Silicone elastomer foams are reviewed. Their
processability, performance, properties and applications
are discussed in some depth, with particular emphasis on
their stability, fire retardance properties and lower smoke
generation and toxicity than organic foams.
USA
Accession no.465884
Item 382High Performance Textiles
Oct.1992,p.4-5
YARN COATING TECHNIQUE
Cogent Ltd. of London, has developed a treatment in
which a cord or strand can be coated with a dilute solution
of a polysiloxane prepolymer which is then pre-cured in-
situ to create a protective sheath around the yarn
encapsulating it. The article supplies comprehensive
details of the process which is seen as having special
relevance to the production of improved dental floss. (US
patent number 5 021 267).
COGENT LTD.EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.465845
Item 383142nd Meeting,Fall 1992,Conference Proceedings.
Nashville,Tn.,3rd-6th Nov.1992,Paper 93,pp.24. 012
COMPRESSION STRESS RELAXATION. II. ANIMPROVEMENT OVER TRADITIONAL TESTSFOR THE EVALUATION OF SEALANTMATERIALSBunting W; Slocum G H; Russell W D
GE Silicones
(ACS,Rubber Div.)
A compression stress relaxation test method consistent
with ISO 3384 for the evaluation of rubber sealing
materials is described. The test measures important
material performance characteristics not measured bytraditional test methods. A comparison of compression
stress relaxation test results with compression set, volume
per cent swell, oil immersion and heat ageing is made
using heat cured silicone rubber and acrylic elastomer oil
pan gasket materials. 2 refs.
USA
Accession no.465622
Item 384Journal of Biomedical Materials Research
26,No.8,Aug.1992,p.979-87
SHORT-TERM RESPONSE OF BRAIN TISSUETO CEREBROSPINAL FLUID SHUNTS IN VIVOAND IN VITRODel Bigio M R; Fedoroff S
Manitoba,University; Saskatchewan,University
The results are reported of a study carried out to determine
how gross physical characteristics of cerebrospinal fluid
shunts and the cellular proliferative response to shunts
contribute to shunt obstruction. The shunt tubing
employed was made of barium-impregnated, silver-
impregnated or unimpregnated silicone rubber. Contact
between the shunt catheter and vascularised brain tissue
was found to be the most important factor in the genesis
of shunt obstruction. 21 refs.
CANADA
Accession no.463797
References and Abstracts
140 © Copyright 2001 Rapra Technology Limited
Item 385Composites Plastiques Renforces Fibres de Verre
Textile
32,No.3,May/June 1992,p.376-80
MANUFACTURING A VALVE COVER WITHSEAL IN ONE WORK STAGESchultheis S M
KRAUSS-MAFFEI AG
Details are given of an injection moulding machine with
which it is possible to produce an automotive valve cover
in glass fibre-reinforced unsaturated polyester BMC
together with its seal of liquid silicone rubber in one cycle.
The manufacturing costs for this process are compared
with those for the traditional two-stage operation.
GERMANY
Accession no.462092
Item 386Plastverarbeiter
43,No.5,May 1992,p.126/9
German
IMAGE PROCESSING SYSTEM FOR THEAUTOMATIC TESTING OF SILICONE RINGS
A South German company has developed an automatic,
optoelectronic testing system whose possibilities include
the a testing of silicone rings for various types of defect.
The system has been designed in such a way that it
requires no subsequent development or modification, and
can be readily adapted both to the actual parts produced
and to the user’s testing requirements. The entire system,
including testing process, operation of the system and its
capabilities, is described.
WIDMANN BILDVERARBEITUNGSSYSTEME
OHGGERMANY
Accession no.462057
Item 387Rubber and Plastics News 2
3,No.17,15th June 1992,p.4
DOW CORNING OFFERINGS STRESSCUSTOMER SUPPORT
Dow Corning has introduced a range of marked silicone
tubing, and a range of silicone materials for medical
applications. Dow works with its customers to make
materials for specific applications. In particular, details
are given of Silastic Rx marked tubing, made from 50
durometer, medical grade silicone elastomer. Also
mentioned is a series of silicone urethane copolymers, a
clear adhesive gel technology, a silicone elastomer foam,
two-part liquid silicone rubbers, and technology for a one-
part formulation of optically clear, medical-grade
elastomers.
DOW CORNING CORP.USA
Accession no.461100
Item 388Polimeri
13,Supplement 1,1992,p.35-8
Serbo-Croatian
SILICON INSULATORSMardesic O;Tisov J;Zelic N
Previously reported data on silicone insulators are
reviewed. The properties of insulators made from silicone
and ceramics are compared and end-use applications
indicated. 9 refs.
EASTERN EUROPE; YUGOSLAVIA
Accession no.461007
Item 389Journal of Applied Biomaterials
3,No.3,Fall 1992,p.239-42.
CLINICAL REVIEWS: MAMMARY IMPLANTSKossovsky N;Papasian N
CALIFORNIA,UNIVERSITY AT LOS ANGELES
The use of silicone rubbers and PU foams in mammary
implants is reviewed with reference to aspects of
bioreactivity, degradation and carcinogenicity. 38 refs.
USA
Accession no.460974
Item 390Materiaux & Techniques
80,No.1-2-3,1992,p.51-4
French
SOLVENTLESS SILICONE COATINGMATERIAL FOR SURFACE MOUNTEDELECTRONIC COMPONENTSPiazza J;Dinallo A J
GE SILICONES
The use of solventless silicone encapsulating materials
for surface mounted electronic components is discussed
with reference to those developed by GE Silicones. Details
are given of their properties, applications and methods of
polymerisation.
USA
Accession no.459670
Item 391Machine Design
64,No.14,9th July 1992,p.52-3
MINERAL-REINFORCED SILICONES TAKETHE HEATDinallo J
GE SILICONES
The features and end-use applications of mineral-filled
silicone polymers, which can be used as replacements for
metals and injection moulded to produce components
withstanding operating temps. as high as 275C continuously,
are described. Applications include encapsulation for
References and Abstracts
© Copyright 2001Rapra Technology Limited 141
electronic devices, automotive components and domestic
appliances. Fillers employed are generally fused amorphous
silica and a small amount of E-glass.
USA
Accession no.459325
Item 392Industria della Gomma
36,No.4,April 1992,p.35-8
Italian
SILICONE RUBBER IN THE AUTOMOTIVEINDUSTRYBourrain P
RHONE-POULENC SA
The use of silicone rubbers in automotive components is
discussed, and the properties and applications of materials
produced by Rhone-Poulenc are described. These include
Rhodorsil heat curing and Rhodorseal room temperature
curing silicone rubbers. Applications examined in particular
detail include seals, spark plug boots, ignition cables,
coolant and heater hoses and oil pan gaskets. 2 refs.
EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE
Accession no.458545
Item 393Revue Generale des Caoutchoucs et Plastiques
69,No.714,May 1992,p.64-6.
French
THINK VACUUM CASTINGCottineau F
MCP EQUIPMENT
An account is given of the MCP process for vacuum
casting prototypes in two-component resins using silicone
rubber moulds.
EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE
Accession no.457572
Item 394Adesione
3,No.1,Jan/Feb.1992,p.16-24
NEW APPLICATIONS OF SILICONES IN THEBUILDING INDUSTRYMusci G
GENERAL ELECTRIC CO.
(In Italian, English and French). The chemistry, molecular
structure and main physical and chemical properties of
silicones are outlined. New applications of silicones in the
building industry are discussed, including structural glazing,
flame retardant barriers, roofing systems and as an opaquing
agent for reflective glass. Detailed comparative results are
given for accelerated ageing tests and weather resistance of
silicone, PU, butyl elastomer, neoprene + chlorosulphonated
PE, chlorosulphonated PE and vinyl elastomer.
EUROPEAN COMMUNITY; ITALY; WESTERN EUROPE
Accession no.457129
Item 395Adesione
3,No.1,Jan/Feb.1992,p.10-5
SILICONE MASTICS IN THE BUILDINGINDUSTRYHoude M
RHONE-POULENC SA
(In Italian, English and French). The use of silicone
mastics in the building industry is reviewed. Different
silicone mastic formulations and their properties are
discussed, and weathering tests are described. Many
types of silicone sealants are now available. All have
different properties to suit specific requirements, but
all are weatherproof. Durability combined with
elasticity, adhesion to the substrate and chemical
resistance account for the increasing use of silicone
sealants in the building industry. Special reference is
made to the ‘Vitrage Exterieure Colle’ building
technique in which glass elements are bonded and
sealants have to maintain their adhesion properties,
long-term, under all weather conditions.
EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE
Accession no.457128
Item 396International Polymer Science and Technology
19,No.2,1992,p.T/33-40
VULCANISATION OF SILICONE RUBBERSSchaetz M
A review of silicone rubber vulcanisation since the 1950s
is given with emphasis on reaction mechanisms and side
reactions. Methods considered are peroxide vulcanisation,
radiation vulcanisation, hydrosilylation reactions and
condensation vulcanisation of functional groups by
reactive crosslinking agents. Applications, e.g. adhesives
and sealants, and specific advantages of each technique
are pointed out. 34 refs. (Full translation of Plasty a
Kaucuk,No.1,1991,p.5).
CZECHOSLOVAKIA; EASTERN EUROPE
Accession no.456643
Item 397Contraception
45,No.5,May 1992,p.453-61
ACCEPTABILITY OF NORPLANT-2 RODS AS AMETHOD OF FAMILY PLANNINGSingh K;Viegas O A C;Ratner S S
SINGAPORE,NATIONAL UNIVERSITY HOSPITAL
Details are given of a five-year contraceptive study using
the Norplant-2 rod system which consisted of two PDMS
rods in which levonorgestrel was incorporated. 5 refs.
SINGAPORE
Accession no.455249
References and Abstracts
142 © Copyright 2001 Rapra Technology Limited
Item 398Biomaterials
13,No.5,1992,p.333-6
DIMENSIONAL STABILITY OFCONDENSATION SILICONE RUBBERSBraden M
LONDON,UNIVERSITY
Linear shrinkage during 24h after setting of a number of
proprietary condensation silicone dental impression
materials was studied. Weight loss and change in volume
were measured over the same time period by weighing
similar specimens in air and water. It was concluded that
the linear shrinkage of condensation silicone rubbers is,
to a first approximation, predictable from the mass of
volatile products lost, with the exception of the highly
filled putty materials. In the latter case the measured
changes are much larger than those predicted theoretically;
this may be a consequence of strains built in during
moulding of specimens. 5 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.454392
Item 399Journal of Biomedical Materials Research
26,No.5,May 1992,p.631-50
DIFFERENCE IN TUMOUR INCIDENCE ANDOTHER TISSUE RESPONSES TOPOLYETHERURETHANES ANDPOLYDIMETHYLSILOXANE IN LONG-TERMSUBCUTANEOUS IMPLANTATION INTO RATSNakamura A;Kawasaki Y;Takada K;Aida Y;Kurokama
Y;Kojima S;Shintani H;Matsui;Nohmi T;Matsuoka
A;Sofuni T;Kurihara M;Mitaya N
JAPAN,NATIONAL INST.OF HYGIENIC
SCIENCES; JAPAN,PUBLIC WELFARE INST.OF
SCIENTIFIC RESEARCH
The long-term (1- and 2-year) adverse tissue responses
including tumour formation by subcutaneous implantation
of PU and silicone films into rats were compared. Tissue
responses around implants were classified into four
groups: (a) tumour, (b) atypical cell proliferation
accompanied by preneoplastic changes, (c) cell
proliferation without preneoplastic changes, (d) no
obvious responses. In both implantation periods, the PUs
gave higher incidents of adverse responses including
tumour formation in comparison to silicone. 29 refs.
JAPAN
Accession no.453090
Item 400Plastics Technology
38,No.5,May 1992,p.78-80
NEW PLASTICS FOR ELECTRONICS
GE Plastics has expanded its Supec PPS line with the
introduction of high ductility and low-flash grades for
surface mount technology and high-performance
connectors. GE Silicones has introduced two new silicone
moulding compounds for electronics and electronics
packing. Hercules has unveiled a brand new resin
chemistry, Sycar silicon-carbon thermosets. They are
currently available in neat resin grade for multilayer
circuit boards and a formulated liquid resin for potting
and encapsulating.
GE PLASTICS; GE SILICONES; HERCULES INC.USA
Accession no.452191
Item 401Advances in Polymer Technology
11,No.2,Summer 1991/92,p.133-40
INITIATION OF A SOLID-STATE EXTRUSIONOF A CROSSLINKED SILICONE RUBBERCohen A;Burmester A F
DOW CHEMICAL CO.
The initiation stage of a plunger-driven extrusion of a
crosslinked silicone rubber material was investigated. The
experiments were performed at room temp. with a series
of capillaries of various diameters positioned in a
conventional Instron rheometer. It was observed that the
extrusion of the rubber started with a cylindrically shaped
‘plug’ which was followed by an ‘apple peel’ shape. This
change in the shape of extrudates corresponded to changes
in the load applied to the plunger. Analysis of this
transition and its variation with the size of the capillary
indicated that interesting physical mechanisms were
involved in this solid-phase processing operation. 14 refs.
USA
Accession no.451474
Item 402Journal of Microencapsulation
9,No.2,April-June 1992,p.183-6
MICROENCAPSULATION OF MENADIONESODIUM BISULPHITE WITH PDMS BY THESPRAY-DRYING PROCESS.CHARACTERISATION BY THERMALANALYSISGronchi P;Del Rosso R;Centola P;Cosentino R F
MILANO,POLITECNICO
Menadione sodium bisulphite was microencapsulated
with a PDMS membrane using spray-drying technology.
Products were characterised by DTA and chemical and
physical methods. 6 refs.
EUROPEAN COMMUNITY; ITALY; WESTERN EUROPE
Accession no.451328
Item 403Analytical Chemistry
64,No.5.1st March 1992,p.347/56
PRESERVING OUR HERITAGE IN STONE
References and Abstracts
© Copyright 2001Rapra Technology Limited 143
Wheeler G S;Schein A;Shearer G;Su S H;Blackwell C
S
IOWA,UNIVERSITY; NEW
YORK,METROPOLITAN MUSEUM OF ART;
SCIENCE & TECHNOLOGY COMMUNICATIONS;
UNION CARBIDE CORP.
Developments in stone consolidation techniques for use
in art conservation are discussed with particular reference
to the use of alkoxysilane monomers or oligomers to form
crosslinked silicate polymers within the matrix of stone
objects. 14 refs.
USA
Accession no.450279
Item 404Plastics and Rubber Weekly
No.1438,6th June 1992,p.8
GE UNVEILS EUROPEAN FUTURE
Silicones are reported to be some of the most versatile
rubber materials on the market, capable of resisting many
chemicals and solvents as well as operating over a wide
temperature range. GE Silicones currently turns over
approximately 650 million US dollars/yr. in these
materials; some of the key developments that the company
sees as being important in the future are outlined.
GE SILICONESEUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.450048
Item 405Macplas
17,No.135,Jan/Feb.1992,p.68-9
Italian
LIQUID SILICONES
A system developed by Ubalit for liquid silicone rubber
processing uses MIR injection moulding machines and
precision moulds produced by the Multicadd computer
aided design and manufacturing system. Some
applications of the process are described.
FIAT SPA; MICROSYSTEM; MIR SPA; UBALITEUROPEAN COMMUNITY; ITALY; WESTERN EUROPE
Accession no.448074
Item 406Journal of Macromolecular Science A
28,No.11-12,Nov/Dec.1991,p.1151-76
SYNTHESIS AND CHARACTERISATION OFPOLYSILANESMatyjaszewski K;Cypryk M;Frey H;Hrkach J;Kwan
Kyu Kim;Moeller M; Ruehl K;White M
CARNEGIE-MELLON UNIVERSITY
The various methods of synthesis of polysilanes are
reviewed aimed at improving control of the polymer
structure and other properties in copolysilanes of various
composition. Particular attention is paid to sonochemical
reductive coupling, ring-opening polymerisation,
modification of polymethylphenylsilylene and solid-state
transitions in copolysilanes. 47 refs.
USA
Accession no.446966
Item 407Progress in Rubber and Plastics Technology
7,No.4,1991,p.308-24
SILICONE ELASTOMERS. TOXICOLOGICALAND OTHER SAFETY ASPECTSCassidy S L
DOW CORNING LTD.
The safety profile of silicone elastomers is reviewed, with
emphasis on major areas of potential hazard, including
toxicity, biodurability, behaviour in fire and elevated
temp., chemical migrants and contaminants, and food
contact and biomedical applications. It is shown that
silicone elastomers exhibit significantly more benign
characteristics than other competing elastomers offered
for the same end-use applications. 63 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.446907
Item 408Gummi Fasern Kunststoffe
45,No.2,Feb.1992,p.76-8
German
NEW SEALANTS BASED ON SILANE-MODIFIED POLYMERSProbster M
TEROSON GMBH
(Paper given at Eurobond 1991 in Wiesbaden). Sealants
formed from polyoxypropylene diol with silyl end-groups
show a high rate of cure, have good UV resistance and
will take paint readily. The properties of a number of such
sealants are described and examples of their application
are given.
GERMANY
Accession no.443327
Item 409Plastics Design Forum
17,No.1,Jan/Feb.1992,p.16
SILICONE ELASTOMER IMPLANTS HELPRELIEVE ARTHRITIC PAIN
Dow Corning is reported to have led development for 20
years in small-bone orthopaedic implants produced from
medical grade silicones. Now, flexible finger, wrist and
toe implants made from the company’s Silastic 100 high
performance silicone elastomer also include titanium
shields or grommets. These are claimed to help prevent
damage to the implants from rough bone edges. Details
are given.
References and Abstracts
144 © Copyright 2001 Rapra Technology Limited
DOW CORNING CORP.; DOW CORNING WRIGHT;
TAMCENAN INC.USA
Accession no.443172
Item 410Advanced Composites Engineering
Feb.1992,p.10-1
IT’S IN THE BAGCooke M
AEROVAC SYSTEMS (KEIGHLEY) LTD.
Vacuum bugging is reported to be a widely-used technique
for moulding advanced composite components. The
technique has conventionally been achieved using a high
temperature, heat stabilised nylon film as the membrane.
The advantages and disadvantages of re-usable silicone
rubber vacuum bags compared to disposable nylon ones
are discussed in detail.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.442996
Item 411European Rubber Journal
174,No.3,March 1992,p.16
SILICONE FEMRING SEEKS D H OKBebbington S
It is reported that women in UK may be the first to have
a new long term contraceptive device; the manufacturer,
Roussel Laboratories, is waiting for the Department of
Health to licence the silicone rubber intra-vaginal ring
which emits contraceptive hormones. Details are given.
ROUSSEL LABORATORIES; SILICONE
DEVELOPMENTS LTD.; UK,DEPT.OF HEALTH;
WORLD HEALTH ORGANISATIONEUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.442133
Item 412Elastomerics
124,No.1,Jan.1992,p.23-4
SILICONE GASKETS INSTALLED IN RACECARS TAKE DRIVERS ACROSS THE FINISHLINE
Select-Sil moulded valve covers and oil pan gaskets from
Freudenberg-NOK General Partnership are demonstrated
to be able to keep automotive engines leak-free at
temperatures as high as 500F. They are used in the
Chevrolet cars and light trucks, and have performed in
the Chevrolet Corvette which won the SCCA World
Challenge Series Team championship. The silicone
gaskets are re-usable and have shown great durability and
reliability.
FREUDENBERG-NOK GENERAL PARTNERSHIPUSA
Accession no.441194
Item 413Elastomerics
124,No.1,Jan.1992,p.10-3
SILICONE HOSES WITHSTAND HIGH HEAT INTURBOCHARGED CLASS 8 TRUCK ENGINESBayne D;Romanowski R;Arthur M
DOW CORNING CORP.; GATES RUBBER CO.
Due to recent changes in EPA emissions standards, truck
manufacturers have been encouraged to use turbocharged
engines to improve fuel economy and reduce output
emissions. Higher operating temperatures have in turn
led to the design of alternative cooling methods for the
charged air to improve fuel efficiency. Air to air methods
of cooling are described and the market which has opened
up for hose materials which will withstand the high heat
environment over long periods of time without significant
degradation. Silicone rubber and the new generation of
silicones which retain plasticity are evaluated.
USA
Accession no.441193
Item 414Rubber World
204,No.6,Sept.1991,p.14-5
LIQUID SILICONES - TAKE TWOMenough T
Information is presented in some detail on liquid siliconerubber systems (LSR), how they come to be
commercialised and how Liquid Silicone Molding
Laboratories (LSM Labs.) became established.
Advantages of these systems over conventional gum
rubbers, details of how to injection mould LSR and
potential problems are also discussed.
LIQUID SILICONE MOLDING LABORATORIESUSA
Accession no.434455
Item 415Adhesion.Principles and Practice for Coatings and
Polymer Scientists.Conference Proceedings.
Kent,Oh.,20th-24th May 1991,Paper 10. 9(12)4
COUPLING AGENTS AS ADHESIONPROMOTERS IN ADHESIVE BONDINGBoerio F J;Dillingham R G;Ondrus D J
CINCINNATI,UNIVERSITY
Edited by: Krauss C J
(Kent State University)
The characteristics of silane primer films applied to metals
and the use of silane primers to enhance the hydrothermal
stability of adhesive bonds to metal are presented. Emphasis
is given to iron/epoxy adhesive joints, titanium/epoxy
adhesive joints, aluminium/epoxy adhesive bonds, rubber
to metal bonding, adhesion of PE to sapphire. 38 refs.
USA
Accession no.430273
References and Abstracts
© Copyright 2001Rapra Technology Limited 145
Item 416137th Meeting Spring 1990.Conference Preprints.
Las Vegas,Nv.,29th May-1st June 1990,Paper 14. 012
SILICONES IN MEDICAL MARKETS - PAST,PRESENT AND FUTUREBrodhagen T W
DOW CORNING CORP.
(ACS,Rubber Div.)
A review is presented of the historic progression of the
use of elastomeric silicones in medical and pharmaceutical
product markets in the USA. Information is included of
the testing of the biocompatibility of materials, process
controls for the manufacture of these materials, and
regulatory implications for their use in device
applications. 6 refs.
USA
Accession no.430144
Item 417Materials News International
No.37,p.6
SILICONE ENCAPSULANT RESISTSCORROSIVE SPACE HAZARDDOW CORNING CORP.
The structure of the Hubble Space Telescope’s solar array
panel, with its 48, 760 silicon solar cells, and its
deployment in space are described. For the flexibleblankets of the solar generator to survive the harsh
environment of an orbit 600km above the earth for five
years, a special multi-laminate compound was developed.
Its structure is described and illustrated. The silver mesh
used for power transfer is surrounded by a symmetrical
sandwich of silicone adhesive, Kapton and glass-fibre
filled with Dow Corning’s space grade encapsulant. The
properties of this encapsulant are listed and other space
applications of it are given.
EUROPEAN COMMUNITY; UK; USA; WESTERN EUROPE
Accession no.425031
Item 418Journal of Applied Polymer Science
42,No.9,5th May 1991,p.2397-403
PERMEABILITY OF SILICONE POLYMERS TOHYDROGENBhide B D;Stern S A
SYRACUSE UNIVERSITY
Permeability coefficients for hydrogen in ten different
types of silicone polymer membranes were measured
in the temp. range 10C to 55C and at pressures up to
about 6.8 atm. Polymers were polydimethyl siloxane,
polyethylmethyl siloxane, polymethylpropyl siloxane,
polymethyloctyl siloxane, polymethyltrifluoropropyl
siloxane, polymethylphenyl siloxane, polydimethyl
silmethylene, polysilethylene siloxane, polysilhexylene
siloxane and poly-m-silphenylene siloxane.
Permeability coefficients decreased slightly with
increasing pressure difference, but increased with
increasing temp., the activation energies being from
1.4 to 4.3 kcal/mol. Permeability coefficients decreased
with increasing bulkiness of functional groups and
decreased considerably when Si-O bonds were replaced
by Si-C bonds. Relevance to gas separation is
suggested. 12 refs.
USA
Accession no.424146
Item 419Journal of Applied Polymer Science
42,No.2,20th Jan.1991,p.383-9
PERMEATION OF DISSOLVED CARBONDIOXIDE IN SYNTHETIC MEMBRANESNakagawa T;Naruse A;Higuchi A
MEIJI,UNIVERSITY
Permeability coefficients of dissolved carbon dioxide
in polydimethyl siloxane, oxygen plasma-treated
polydimethyl siloxane, PS, LDPE and polyamide-6
membranes were studied by applying a carbon dioxide
electrode in a liquid to liquid diffusion cell. Boundary
layer resistance was estimated for the plasma-treated
and non-treated polydimethyl siloxane. Plasma
treatment, which made the surfaces hydrophilic
without changing polymer bulk properties, decreased
the boundary layer’s thickness and increased the
apparent permeability coefficient in the liquid phase.
18 refs.
JAPAN
Accession no.418477
Item 420Integration of Fundamental Polymer Science and
Technology.
Barking,Elsevier Science Publishers,1989,p.308-12.
012
CONFORMATIONAL DISORDER INPOLYDIETHYLSILOXANE (PDES)Kogler G;Loufakis K;Bahnert R;Moller M
FREIBURG,INSTITUT FUR
MAKROMOLEKULARE CHEMIE
Edited by: Lemstra P J;Kleintjens L A
(Eindhoven,University of Technology; DSM
Research BV)
DSC, solid state NMR, optical microscopy and
rheological measurements were used to examine the phase
diagram of polydiethylsiloxane. The mobility of the chains
in the different phases was investigated. Changes that
occurred upon shearing and the influence of quenching
are discussed. 6 refs.
EUROPEAN COMMUNITY; WEST GERMANY; WESTERN
EUROPE
Accession no.416691
References and Abstracts
146 © Copyright 2001 Rapra Technology Limited
Item 42143rd Annual Conference and Focus ’88;Proceedings.
Cincinnati,Ohio,1st-5th Feb.1988,Session 24-B,pp.4. 627
BONDING TO PLASTIC SURFACES THROUGHSILANE PRIMERS AT MODERATETEMPERATURESPlueddemann E P
DOW CORNING CORP.
(SPI,Reinforced Plastics/Composites Institute)
Silane primers have been developed that will give water
resistant bonds of virtually all thermoplastics to metals or
silaceous surfaces if the polymer is fused against the primed
surfaces. The same primers may be effective in bonding a
lower-melting polymer in its fused state against another
primed higher melting polymer. In some circumstances
adhesion between polymers is desired where fabrication
conditions are limited to room temperature or only mildly
elevated temperatures. A partially hydrolysed vinylbenzyl
cationic silane (Z6032) was especially effective on oriented
polyethylene fibres. A new silane modified melamine resin
was especially effective in bonding urethanes to
engineering thermoplastics either as a primer or as an
additive to the urethanes. 7 refs.
USA
Accession no.414880
Item 422Adhasion
34,No.11,Nov.1990,p.32/5
German
ECONOMIC JOINTING WITH SILICONERUBBEREngelmann H
PCI POLYCHEMIE
A description is given of the uses and advantages of
silicone rubber sealants in the building industry.
GERMANY
Accession no.411463
Item 423Revue Generale des Caoutchoucs et Plastiques
67,No.696,May 1990,p.224-5
French
ADHESIVE AND NON-ADHESIVE BEHAVIOUROF SILICONE COMPOSITIONSSchorsch G
RHONE-POULENC SA
The nature of silicone polymers is discussed and examples
of adhesive and non-adhesive behaviour given. The
dichotomy is further elaborated under three headings: (a)
the behaviour of a dimethylsilicone chain on a solid
surface, (b) the properties of RTV silicones and (c) the
properties of accelerated RTV silicones, recently
introduced for silicone coatings.
EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE
Accession no.410348
Item 424Materiale Plastice
27,No.1,Jan/March 1990,p.50-3
Rumanian
SILICONE RUBBERS. I. CONTRIBUTIONS TOSILICONE RUBBER SYNTHESIS BY HOTVULCANISATIONMarcu M;Stiubianu G;Lazarescu S E;Streba E;Stanciu
A
INSTITUTUL DE CHIMIE MACROMOLECULARA
PETRU PONI
A review is presented of results on the synthesis of hot
vulcanised silicone rubbers. The anionic and cationic
polymerisation, compounding and vulcanisation of the
rubbers are discussed. 22 refs.
EASTERN EUROPE; RUMANIA
Accession no.408497
Item 425Handbook of Elastomers.
New York,Marcel Dekker Inc.,1988,p.551-615. 011
ADVANCES IN SILICONE RUBBERTECHNOLOGYPolmanteer K E
KEP ENTERPRISES
Edited by: Bhowmick A K;Stephens H L
34 refs.
USA
Accession no.406504
Item 426Advanced Materials
2,No.9,Sept.1990,p.398-404
CERAMICS FROM ORGANOMETALLICPOLYMERSPeuckert M;Vaahs T;Brueck M
HOECHST AG
This review of non-oxide ceramics concentrates mainly
on the preparation and properties of silicon preceramic
polymers. Silicon carbide and silicon nitride precursors
are discussed in detail. Pyrolysis converts the polymers
into the ceramic state. The inorganic polymers can be
liquefied and are soluble, which offers advantages over
ceramic powder or metallurgical processing and gives rise
to many novel applications such as ceramic coatings,
binders, impregnations or spun fibres. 70 refs.
HOECHST AG; NIPPON CARBON CO.; UBE
INDUSTRIES LTD.EUROPEAN COMMUNITY; WEST GERMANY; WESTERN
EUROPE
Accession no.406448
Item 427Rubber World
202,No.3,June 1990,p.33-7
References and Abstracts
© Copyright 2001Rapra Technology Limited 147
SILICONE USAGE EXPANDING IN EUROPEANAUTOMOTIVE APPLICATIONSFinney D
GENERAL ELECTRIC CO.,SILICONES DIV.
The versatility of silicone chemistry, couple with the
reliability, safety and superior performance of these
inorganic materials is cited for their ability to penetrate
approximately 40 applications on the average US
automobile. A number of present and potential automotive
applications are described particularly in engine hot spots.
USA
Accession no.404022
Item 428Journal of Materials Science
25,No.6,June 1990,p.3017-23
GAS-INDUCED DAMAGE IN ELASTOMERICCOMPOSITESBriscoe B J;Zakaria S
LONDON,UNIVERSITY,IMPERIAL COLLEGE
Damage in elastomers caused by gases escaping from the
polymer matrix was studied using transparent silicone
elastomer (Sylgard 184) filled with low concentrations
of glass spheres that had been given various surface
treatments to improve or reduce polymer-filler interaction.
Optical microscopy techniques were developed to
examine the internal cracks found during a typical gas-induced rupture cycle. Stress-strain data indicated that
the filler particles significantly modified the stress fields
in the elastomer during gas-induced rupture. Use of
dynamic mechanical properties as a guide to the extent
of damage is discussed. 18 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.403669
Item 429Tech XIII.Proceedings of the Pressure Sensitive Tape
Council’s Thirteenth Annual Technical Seminar.
Itasca,Il.,2nd-4th May 1990,p.155-58. 6A1
ADHESIVE/SILICONE INTERFACEJones J D
DOW CORNING CORP.
(Pressure Sensitive Tape Council)
The interfacial phenomena which occur between the
pressure sensitive adhesive layer and the release coating
are described, together with possible solutions to the
problems which occur.
USA
Accession no.402481
Item 430Meeting Technical & Business Challenges in
Specialised Markets.Proceedings of the ACS Fall 1989
seminar.
Rosemont,Il.,22nd-25th Oct.1989,p.141-52. 6A1
SILICONE SEALANTS AND ADHESIVES FORAEROSPACE/DEFENCE APPLICATIONSBaile M;Fuson S E
DOW CORNING CORP.
(Adhesive & Sealant Council)
A review of the properties and use of silicone sealants
and adhesives for the aerospace industry is presented. It
includes fluorosilicone sealants, sealants for munition
casings, sealants for missiles and aircraft fairing. Silicone
interlayer adhesives for the bonding of substrates used in
canopies and periscopes are also included as well as
general purpose silicone sealants and adhesives which can
be tailored to requirements. Properties of some products
are shown.
USA
Accession no.399401
Item 4313,no.3,1990,p.31/1-31/91
SILICONE RUBBERSTrego B R;Winnan H W
DOW CORNING LTD.; RAPRA TECHNOLOGY
LTD.
Rapra Review Report No.31
A review is presented on silicone rubbers covering basic
formulation and cure chemistry, properties, processing
methods and applications. A literature search from theRapra database on silicone rubbers is included giving
references and abstracts from relevant documents relating
to the report with a subject index. 471 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.398996
Item 432Rubber and Plastics News
18,No.22,15th May 1989,p.12
FDA STUDYING SILICONE RUBBERCONTRACEPTIVEMoore M
An advisory committee to the FDA is urging the
Administration to approve the use of Norplant. Said to
be as effective as birth control pills and safer to use,
Norplant consists of six silicone rubber capsules
containing levonorgestrel. When implanted under the skin
the capsules provide a woman with a constant miniscule
dose of hormone for up to 5 years. According to the
Population Council, the hormone inhibits ovulation and
prevents sperm from entering the uterus. Results of tests
on 2,470 women are reported.
USA
Accession no.381471
Item 433Rubber and Plastics News
18,No.24,12th June 1989,p.36-41
References and Abstracts
148 © Copyright 2001 Rapra Technology Limited
EFFECT OF CROSSLINK STRUCTURE ONPDMSHalladay J R
LORD CORP.
This detailed review describes studies which examine the
effect of network crosslink distribution on the elastomeric
properties of polymethylsiloxane (PDMS). From the work
by J.E.Mark, the term ‘bimodal networks’ has become
popular, which indicates the crosslinking of long polymer
chains with a large mole fraction of short polymer chains.
The majority of data published has focused on the
elucidation of molecular aspects of rubber elasticity, and
have begun to associate increased tear and tensile strength
with the use of bimodal distribution of polymer chains,
since silicone elastomers are not noted for being over-
endowed with either of these two properties. 17 refs.
USA
Accession no.380899
Item 434Handbook of Pressure Sensitive Adhesive
Technology.2nd edn..
New York,1989,p.601-26. 6A1
SILICONE RELEASE COATINGSJones J D;Peters Y A
DOW CORNING CORP.
Edited by: Satas D
(Satas & Associates)
Silicone release coatings are used for bar code labels,
product labels, price tags, care and warning labels, name
tags, display banners, bumper stickers, packaging tapes,
self adhesive wall coverings, floor and carpet tiles and
transfer tapes. Consideration is given to physical
properties, chemistry, types of coating, solvent-borne
release coatings, water-borne systems, solventless silicone
coatings, radiation curable release coatings, coating
evaluation. 12 refs.
USA
Accession no.375985
Item 435Handbook of Pressure Sensitive Adhesive
Technology.2nd edn..
New York,1989,p.508-17. 6A1
SILICONE PRESSURE SENSITIVE ADHESIVESSohieski L A;Tangney T J
DOW CORNING CORP.
Edited by: Satas D
(Satas & Associates)
The adhesives are based on a polymer or gum and a
tackifying resin. High molecular weight polydimethyl
siloxane or polydimethyldiphenyl siloxane containing
residual silanol functionality (SiOH) on polymer chain
ends. The resin is a three dimensional silicate structure that
is endcapped with trimethylolsiloxy groups (OSiMe3).
Polycondensation results in a rheologically suitable
material. Cure chemistry after solvent evaporation is
described. The use of primers to obtain adhesion to some
tape backing materials is discussed. Typical properties,
industrial and medical applications are mentioned. 11 refs.
USA
Accession no.375952
Item 436Journal of Coated Fabrics
17,April 1988,p.279-87
NEW SILICONE FOAM ENHANCES HIGH-PERFORMANCE FABRICSHartley K R
GENERAL ELECTRIC CO.,SILICONE PRODUCTS
DIV.
Details are given of RTF-762 silicone foam for high-
performance fabric applications requiring silicone
properties and light weight. The compound features a
proprietary formulation which is claimed to provide a
level of mechanical strength not previously attainable with
foamed RTV materials.
USA
Accession no.372775
Item 437Adhesives,Sealants,and Coatings for Space and Harsh
Environments.Conference Proceedings.
Denver,Colorado,7-9 April 1987,p.281-91. 63Tr.Sp.
DURABILITY OF SILICONE SEALANTSOwen M J;Klosowski J M
DOW CORNING CORP.
(ACS,Div.of Polymeric Materials Science & Engng.)
The environmental durability of silicone sealants is
reviewed, particular emphasis being placed on PDMS but
with reference to polyphenylmethylsiloxanes and the
fluorosilicone, polytrifluoropropylmethylsiloxanes.
Responses to various environmental stresses, including
those associated with weathering, such as ozone and
temperature extremes, as well as electrical stresses, such
as corona discharge, are discussed. This behaviour is
related to the surface and bulk properties of silicones and
particularly to the low intermolecular forces and high
chain flexibility of the polymer molecules. 27 refs.
USA
Accession no.364141
Item 438European Adhesives & Sealants
5,No.3,Sept.1988,p.3/6
BEWARE THE ACETOXYWoolman R
ADSHEAD RATCLIFFE & CO.LTD.
A review is presented of the many types of silicone
sealants available, their properties, applications and
References and Abstracts
© Copyright 2001Rapra Technology Limited 149
method of cure. The need for careful selection of the
correct sealant type for a particular application, especially
with regard to volatile products evolved during the curing
process, is emphasised. Particular reference is made to
silicones using acetoxy cure systems. Their irritant factor
and corrosive effect on concrete and metals is outlined.
UK
Accession no.360590
Item 439Synthetic Adhesives and Sealants, Chichester, John
Wiley & Sons, 1987, p.89-111. 6A1
SILICONE ADHESIVES, SEALANTS ANDCOUPLING AGENTSWake W C
CITY UNIVERSITY,LONDON
Edited by: Wake W C
A detailed review is given with particular reference to
chemical rather than physical and engineering aspects of
joints involving silicone polymers and other silicone-
containing compounds. It includes synthesis of monomers
and preparation of polymers, synthesis of silane coupling
agents, crosslinking, primers for silicone adhesives, use
of fine particle fillers in silicone adhesives and sealants,
and durability of silicone adhesives and sealants. 46 refs.
UK
Accession no.359907
Item 440Revue Generale des Caoutchoucs et Plastiques
65,No.676,March 1988,p.105-10
French
ADHESION OF SILICONE ELASTOMERS:DEVELOPMENT OF AN ON-LINE METHODBarquins M;Pouchelon A
CNRS,LABORATOIRE DE MECANIQUE DES
SURFACES; RHONE-POULENC SA
The adhesion and peel characteristics of viscoelastic
materials are discussed as an introduction to the
development of equipment for the continuous monitoring
of the effects of incorporating compounding ingredients.
Tests were carried out on silicone rubber sheet formed
several days beforehand on a calender. The test machine
can also be used to characterise the tack of thin adhesive
films especially with respect to stick-slip effects. 16 refs.
FRANCE
Accession no.352270
Item 441Gummi Fasern Kunststoffe
40,No.9,Sept.1987,p.506-8
German
MANUFACTURE WITH SOLID AND LIQUIDSILICONE RUBBERS
Proceedings are reported of the Wurzburg South German
Plastics Federation and the Wurttemburg Engineering
Society meeting in Stuttgart, 21-22 May 1987. A general
description of solid silicone rubber is followed by
suggestions for the design of suitable extruders, infrared
and hot air ovens for crosslinking, and the press moulding
of silicone rubbers. Liquid silicone rubbers are discussed
as an alternative to the solid material and the use of two-
component silicone rubbers is described. Injection
moulding of the two forms is compared and the possibility
of multi-component metering and mixing of the liquid
rubber discussed.
WURTTEMBURG ENGINEERING SOCIETY;
WURZBURG SOUTH GERMAN PLASTICS
FEDERATIONWEST GERMANY
Accession no.348992
Item 442Plaste und Kautschuk
34,No.5,May 1987,p.183-90
German
PHOTOCROSSLINKING OF SILICONESMueller U;Timpe H J;Roesler H
MERSEBURG,TECHNISCHE HOCHSCHULE; VEB
CHEMIEWERK NUENCHRITZ
This is a detailed review on developments in
photocrosslinking of silicones. Principles of
photochemical curing are discussed, types of
photocrosslinkable silicones described and aspects of
application considered. Main application areas for
photocrosslinked silicones are in the production of
printing plates and photoresists. 107 refs.
EAST GERMANY
Accession no.348715
Item 443Pitture e Vernici
63,No.8,Aug.1987,p.13-33
RHODORSILMolteni C
(Italian and English). A detailed account is presented of
the chemistry and technical properties of silicone
polymers in building preservation and restoration. 21 refs.
RHONE-POULENC ITALIA SPAITALY
Accession no.348044
Item 444132nd Meeting,Fall 1987.Preprints.
Cleveland,Ohio,Oct.6-9,1987,Paper 9
SILICONE RUBBER, ITS DEVELOPMENT ANDTECHNOLOGICAL PROGRESSPolmanteer K E
(ACS,Rubber Div.)
The development and technological progress of silicone
rubber since it first became commercially available within
References and Abstracts
150 © Copyright 2001 Rapra Technology Limited
the USA in 1944 from both the Dow Corning Corp. and
the General Electric Co. are discussed. The key advances
in tensile strength, room temp. vulcanisation, copolymers,
new silicas, water-based compounds, high tear/tough
compounds, liquid rubber, the Silastic Compounding
System, cost/performance and medical grade rubber,
responsible for the technological progress of silicone
rubber are chronologically traced from 1944 to 1987.
Finally, the combined silicone rubber technology as it
commercially exists in 1987 is discussed. 33 refs.
DOW CORNING CORP.; GENERAL ELECTRIC CO.
USA
Accession no.344588
Item 445Elastomerics
119,No.8,Aug.1987,p.20-2
TECHNICAL INNOVATIONS ENHANCECOMMERCIAL VALUE OF SILICONE RUBBERToub M R
GENERAL ELECTRIC CO.
The article looks at the value of silicone rubber in a
diversified elastomer market. Silicone sales trends are
examined with respect to physical properties and
application areas such as the automotive, aerospace, wire,
cable and medical markets. 4 refs.
GENERAL ELECTRIC CO.,SILICONE PRODUCTS
DIV.
USA
Accession no.341536
Item 446High Performance Polymers: Their Origin and
Development.Proceedings of the Symposium held New
York,15-18 April 1986.
New York,NY,Elsevier Science Publishing
Co.Inc.,1986,p.381-8. 63E
HISTORY OF SILICONE ELASTOMERSFearon F W G
DOW CORNING CORP.
Edited by: Seymour R B;Kirshenbaum G S
(ACS)
Key discoveries in the development of silicone elastomer
technology were reviewed with comment on monomer
(chlorosilanes, siloxanes) synthesis and polymerisation
(thermal condensation, ring-opening, emulsion),
reinforcement (fumed silica fillers, copolymerisation,
block copolymers, blends, IPN’s), crosslinking
(peroxides, reactive group incorporation, RTV systems,
one- and two-component systems), processing and
fabrication, and properties. Composition and structural
features responsible for the characteristic properties were
discussed and related to applications. 27 refs.
USA
Accession no.330649
Item 447Cyclic Polymers.
Barking,Elsevier Applied Science Publishers
Ltd.,1986,p.85-133. 6116
PREPARATION OF CYCLIC POLYSILOXANESWright P V;Beevers M S
ASTON,UNIVERSITY; SHEFFIELD,UNIVERSITY
Edited by: Semlyen J A
(York,University)
Essential procedures used in preparing and analysing the
products of cyclisation reactions and in separating
fractions of cyclic siloxane material were described in
this review. The formation of siloxane rings in equilibrates
and in irreversible processes, the critical concentration
in polysiloxane equilibrates (theory,influence of
substituents on cyclic formation, thermodynamic
influences on equilibrium position, distribution and
configurational isomers of cyclic phenylmethylsiloxanes),
preparation of siloxane cyclic residues (reaction
quenching, fractionation), analytical GPC (cyclic and
linear distributions within macrocyclic residues),
preparative GPC, and ring-chain equilibration of siloxane
copolymers (polytetramethyloxadisilacycloheptane,
copolymers of polysiloxane and PS segments) were
discussed with relevant equations. 75 refs.
UK
Accession no.329122
Item 448Applied Polymer Science 2nd Edn.,ACS Symposium
Series 285.
Washington D.C.,1985,p.1117-40. 012
RESINS AND ADDITIVES CONTAININGSILICONThames S F
SOUTHERN MISSISSIPPI,UNIVERSITY
Edited by: Tess R W;Poehlein G W
(ACS,Div.of Polymeric Materials Science & Engng.)
Silicon and carbon compounds were compared by
considering inductive effects and (p-d) pi bonding, bond
strengths (silicon bonds to halogen, carbon including
double bond, hydrogen, oxygen and nitrogen). The
characteristics of silicone polymers (enhanced thermal
stability, higher water repellency, incompatibility with
organic materials) and their resultant applications, silicon-
containing polymers (high-temperature coatings, blends),
pigmentation, silicones as water repellents, and silicones
as additives (paint formulation, coupling agents,
incorporation into main chain to lower Tg of polyamides
and polyimides). 29 refs.
USA
Accession no.320195
Item 449Kautchuk und Gummi Kunststoffe
39,No.1,Jan.1986,p.33-6
References and Abstracts
© Copyright 2001Rapra Technology Limited 151
German
SILICON RUBBERS - A SURVEYBittera J
WACKER CHEMIE GMBH
A report on silicon rubbers is given which divides the
materials into different crosslinking categories. These are:
one- and two-component RTV types; addition
crosslinkable HTV types (liquid, dispersion and solid
rubbers); peroxide crosslinkable rubbers; and irradiation
crosslinkable HTV types. Properties and application areas
for these rubbers are indicated. (DKG Conference,
Hanover,March 1985).
WEST GERMANY
Accession no.317150
Item 450Adhesives Age
29,No.6,31st May 1986,p.8-11
SILICONE SEALANT TECHNOLOGY,MARKETS CONTINUE TO GROWElias M
SEALANTS TREMCO INC.
An overview of one-component silicone sealant
technology and applications is presented, with
information being provided on the chemistry of these
sealants, defining the desired property profile,
compounding and end-use applications. Basic high,
medium and low modulus formulations containing
acetoxy, oxime and amine crosslinkers are tabulated
along with suitable fillers. 5 refs.
USA
Accession no.315239
Item 451Advances in Polymer Science
No.68/69,1985,p.216-25
POLYSILOXANESPenczek S;Kubisa P;Matyjaszewski K
The literature on the synthesis of polysiloxanes by cationic
ring-opening polymerisation is reviewed. Aspects covered
include the synthesis of polydimethylsiloxanes from
octamethylcyclotetrasiloxane, telomerisation,
polymerisation of alkylhydrosiloxanes, macrocyclisation,
and the polymerisation mechanism. 35 refs.
POLAND
Accession no.304786
Item 452Manufacturing Chemist
56,No.11,Nov.1985,p.59
COMPARING SILICONE COST-EFFECTIVENESSAlexander P
A review is given of silicone-based cosmetic raw
materials, including polyether polysiloxanes, with an
examination of their cost-effectiveness, particularly as
functional, rather than fashionable, constituents of hair
care preparations.
UK
Accession no.301333
Item 453Plastics for Electronics.
Barking,Elsevier Applied Science Publishers
Ltd.,1985,pp.67-97. 6E
SILICONE PROTECTIVE ENCAPSULANTS ANDCOATINGS FOR ELECTRONIC COMPONENTSAND CIRCUITSDavis J H
DOW CORNING LTD.
Edited by: Goosey M T
(Dynachem Corp.)
Silicones were defined and their physical properties
(thermal and oxidative stabilities, stability in physical and
dielectric characteristics with temperature, surface,
handling, fire resistance, combustion products, chemical
purity, low water absorption), production and typical
products were indicated before reviewing the different
types of silicone and their application in electronics. One-
and two-component elastomeric sealants and
encapsulants, conformal coatings and impregnating resins,
transfer moulding compounds, performance, high purity
coatings and adhesives, insulating and constructional
materials, wire and cables, silicone aids in electronic
production, and future developments were discussed. 20
refs.
UK; USA
Accession no.300427
References and Abstracts
152 © Copyright 2001 Rapra Technology Limited
Subject Index
© Copyright 2001 Rapra Technology Limited 153
Subject Index
AABRASION RESISTANCE, 14 34
42 119 145 161 218 233 306313 334 347 382
ABS, 14 237 238ACCELERATED TEST, 269 338
394 395ACCELERATOR, 304 329 331ACID RESISTANCE, 74 249 293ACOUSTIC INSULATION, 367
381ACRYLIC ELASTOMER, 287 291
383ACRYLIC RESIN, 14 247 286 379
390 422ACTIVATION ENERGY, 200 246
312ACTIVATOR, 304ADDITION CURING, 163 165ADDITION POLYMERISATION,
64 129 143 213 423ADDITION REACTION, 17 34 41
65 89 250 261 263ADDITIVE, 14 25 26 37 38 58 81
92 98 103 105 129 131 138 159167 181 185 187 188 194 200202 218 219 222 237 238 246248 249 250 292 293 295 304311 312 325 331 342 346 363372 379 392 421 440 448
ADHESION, 25 26 59 60 64 65 7789 90 97 105 115 125 136 138150 168 186 206 229 236 238250 261 295 313 338 370 377380 381 390 392 394 395 415423 429 440 448
ADHESION PROMOTER, 38 81201 415
ADHESIVE, 40 52 75 121 126 140147 238 244 338 368 372 377380 387 396 417 430 434 435439 440 453
ADHESIVE TAPE, 96 380 429ADSORPTION, 32 70 300AEROSPACE APPLICATION, 7
15 72 168 185 219 255 258 319336 343 363 377 430 431 445
AESTHETIC, 14 237AGEING, 20 129 131 138 202 205
217 219 248 249 250 269 280287 291 313 343 363 394
AIR BAG, 25 42 63 77 121 123126 144 159 161 255 313 404
AIR CONDITIONING, 319
AIR CURING, 379AIR ENTRAPMENT, 414AIR EVACUATION, 227AIR INTAKE SYSTEM, 64AIR POLLUTION, 137ALKOXYSILANE, 10 211 250ALLERGY, 30 100ALUMINIUM FOIL, 303 353ALUMINIUM HYDROXIDE, 17
41 109 371ALUMINIUM OXIDE, 10 162AMINOPROPYLTRIETHOXYSILANE,
274AMINOSILANE, 408AMMUNITION, 295ANALYSIS, 28 69 92 94 200 208
217 225 246 253 292 294 307310 318 325 326 342 347 447
ANCILLARY EQUIPMENT, 2 359ANIMAL TESTING, 217ANTI-ADHESIVE PROPERTIES,
26 138ANTI-FOAMING AGENT, 140
304 368ANTIFOULING, 43ANTI-SCORCH AGENT, 53ANTI-SLIP PROPERTIES, 25ANTIOXIDANT, 293 304ANTISTATIC PROPERTIES, 218ARAMID FIBRE, 303ARC RESISTANCE, 137 219ARCHITECTURAL
APPLICATION, 138ARMCHAIR, 14ART, 138 403ARTIFICIAL BONE, 4 373 409ARTIFICIAL BREAST, 26 69 111
122 152 195 199 208 216 217242 259 279 283 296 318 350389
ARTIFICIAL HIP, 344ARTIFICIAL JOINT, 373ARTIFICIAL LIMB, 360ARTIFICIAL MUSCLE, 178ARTIFICIAL OESOPHAGUS, 361ARTIFICIAL ROCK, 62ARTIFICIAL SKIN, 325ARTIFICIAL TEETH, 14ARTIFICIAL TENDON, 174ASSEMBLY, 91 121AUTOCLAVE, 131 341AUTOIMMUNE DISEASE, 298
299AUTOMATION, 2 104 121 126
150 193 234 235 243 248 256
326 374 385 393AUTOMOTIVE APPLICATION, 6
7 11 13 15 25 26 27 35 40 42 4854 60 63 64 72 77 79 82 89 103105 114 118 121 123 124 126144 150 159 161 163 166 168175 179 181 185 191 193 194196 202 204 215 219 226 235238 243 250 255 257 258 263269 273 275 284 287 290 291294 303 311 313 321 325 327339 349 353 355 363 364 367368 375 377 378 380 381 385391 392 404 405 408 412 413427 431 445
AXLE, 38
BBABY FEED BOTTLE, 37 224
304 364BACTERIA, 236 268 366BAG, 352BALLOON, 30 176BALLOON CATHETER, 29BARIUM, 384BARREL, 179BARREL TEMPERATURE, 200
227 229 246BARRIER, 168 331 352 394BATH, 238BELLOWS, 250BELT, 306 313BENCH, 347BENDING STRENGTH, 4BENZOYL PEROXIDE, 33 112BETA RAY, 239BETA-ESTRADIOL, 340BIDET, 422BINDER, 187 403 426BIOCHEMISTRY, 217 253 298BIOCOMPATIBILITY, 14 23 24
25 30 31 39 57 61 68 71 87 91100 128 131 133 134 135 172173 174 186 197 199 203 206236 239 255 265 266 268 278279 280 281 283 296 315 384389 399 407 409 416
BIODEGRADATION, 134 216 217283 296 298 340 366
BIOLOGICAL ATTACK, 370 389BIOMATERIAL, 23 24 31 61 71
80 87 128 133 135 172 174 186198 199 206 239 247 278 280281 283 286 296 297 298 300
Subject Index
154 © Copyright 2001 Rapra Technology Limited
308 314 315 361 370 399BIOMEDICAL APPLICATION, 21
30 31 39 131 188 197 217 283389 399
BLEED-THROUGH, 203BLEEDING, 218 219BLEND, 17 41 68 118 200 237 238
276 328 446 448BLOCKING RESISTANCE, 103BLOOD CONTACT
APPLICATION, 131 158 296BLOWING AGENT, 88 136BOND STRENGTH, 11 59 60 125
415 448BONDING, 9 59 64 89 125 202
211 218 295 338 392 421BONDING AGENT, 52 147 295BOROSILICATE, 295BOTTLE, 37 224BREAK RESISTANCE, 189BREAKING STRENGTH, 7BREATHABILITY, 168BRIDGE, 72BUILDING APPLICATION, 26 40
72 76 138 140 187 215 226 238324 352 362 363 365 394 395404 422 423 431 438 443
BUMPER, 159BURST STRENGTH, 428BUSHING, 41 229 367BUSINESS MACHINE, 194 219
234 255
CC-FRAME, 150CABLE, 6 11 20 26 33 106 112
159 185 219 249 250 303 311313 332 343 352 353 363 371392 445 453
CABLE CONNECTOR, 15 185CABLE SUPPORT, 319CALCIUM CARBONATE, 1 256
408CALORIMETRY, 221CAP, 204 222CAPACITY, 226CAPILLARY RHEOMETRY, 246
292 310CAPSULE, 239 323 432CAR, 25 26 105 150 159 185 193
194 202 219 238 250 263 269294 303 311 313 325 353 363380 385 392 405
CARBON BLACK, 46 105 127218 250
CARBON DIOXIDE, 303 419CARBON FIBRE, 19 165 295 336
400CARBORANE SILOXANE
POLYMER, 371CARCINOGEN, 111 208 242 304
350 389 399CASING, 194CAST, 45 107 141 182 393CASTING, 14 26 175 194 237 295
331 357 393CATALYST, 5 17 38 81 88 95 97
157 201 202 232 251 256 400408 434
CATALYTIC CONVERTER, 219CATHETER, 24 29 100 147 156
163 176 206 268 311 370 384CAVITY PRESSURE, 104CELL CULTURE, 23 186 296CELLULAR MATERIAL, 14 88
94 99 136 192 238 285 306 352381 387 389 392 394 436
CERAMIC, 13 155 164 187 312338 352 388 422 426
CERAMIC FIBRE, 426CEREBROSPINAL FLUID
SHUNT, 221CERTIFICATION, 234 243 262
263 353CHAIN SCISSION, 131 200 363CHAIR, 14CHALK, 408CHARACTERISATION, 51 145
225 239 316CHEMICAL MODIFICATION, 3
21 56 65 75 92 103 131 202217 301 406
CHEMICAL PROPERTIES, 7 1114 20 26 48 65 67 69 74 77 8191 103 118 119 131 148 159168 169 185 202 218 240 417425 426 439
CHEMICAL RECYCLING, 263303 311
CHEMICAL RESISTANCE, 7 1114 20 26 35 48 60 65 67 74 7781 91 103 118 119 131 148 159168 169 185 191 202 218 219240 249 293 295 313 336 363367 377 380 381 385 394 395407 431
CHEMICAL STRUCTURE, 5 8 2126 36 65 72 91 112 131 135 138177 185 187 200 212 219 255394 426 450
CHIP, 75CHLOROSILANE, 328 363 446CHONDROITIN SULFATE, 283CHROMATOGRAPHY, 101 200
225
CLAMP FORCE, 2 150 179 229234 235 248 326 341 374 385
CLAY, 110 331CLEAN ROOM, 229 262 408CLOSED MOULD, 295 311CLOTHING, 25 168 263 303 311
313 353CO-ROTATING EXTRUDER, 246
309COATED FABRIC, 14 25 42 63
161 168 255 263 303 313 353436
COATED PAPER, 25 346COATING, 3 6 25 40 42 43 44 59
72 73 77 103 115 137 139 161187 233 237 238 250 263 274289 293 295 303 313 319 331346 350 353 364 367 370 377378 379 380 382 389 390 394404 423 434 448 453
COCHLEAR IMPLANT, 265COEFFICIENT OF FRICTION,
103 218COEXTRUSION, 35 100COINJECTION MOULDING, 26
60 102 119 173 179 185 261COLD CURING, 14 26 363COLD RUNNER, 2 9 102 104 119
150 173 193 204 207 227 235248 273 282 311 385
COLLAGEN, 80 217 283 293 361COLORABILITY, 219COLORANT, 229 237COLOUR, 2 14 131 157 218 219
229 237 248 295 302 311 331408 422
COMBUSTION, 185 263 352 453COMMERCIAL INFORMATION,
40 60 91 120 126 136 179 223306 369 414 426
COMPATIBILITY, 15 21 102 103290 377
COMPETITIVENESS, 381COMPLEMENT ACTIVATION,
268COMPOSITE, 14 19 33 50 55 80
89 127 142 149 150 153 183196 210 238 240 245 246 251263 275 295 303 317 319 323335 336 337 353 360 374 382385 391 400 410 417 426 428
COMPOUND, 26 202 249 269 292342 417
COMPOUNDING, 14 26 40 77137 185 189 200 202 248 250309 311 342 363 392 424 450
COMPRESSION MOULDING, 1456 77 91 163 185 200 234 269
Subject Index
© Copyright 2001 Rapra Technology Limited 155
342 369COMPRESSION PROPERTIES,
14 294 383COMPRESSION SET, 65 77 95 97
154 166 179 202 218 219 248249 250 269 291 342 383 441
COMPRESSION STRESSRELAXATION, 219 269 367383
COMPUTER AIDED DESIGN, 2864 83 141 180 237 238 294 310405
COMPUTER AIDEDMANUFACTURE, 405
COMPUTER APPLICATION, 52243
COMPUTER CONTROL, 104 193360 385 393
COMPUTER SIMULATION, 4764 105 310
CONCRETE, 352 422CONDENSATION
POLYMERISATION, 85 143191 328 423 435 446
CONDUCTIVE COATING, 289CONDUCTIVE RUBBER, 218
250 263 275 289 303 311 312336 353
CONFERENCE, 104 105 138 200202 217 218 219 235 246 269283 294 295 307 309 310 325326 331 342 383 408 441
CONNECTOR, 27 60 106 114 235400
CONSERVATION APPLICATION,403
CONSTRUCTION, 352CONSUMPTION, 40 77 179 185
226 255 368 376CONTACT ANGLE, 20 21 65 97
167 205 206 236 239CONTACT LENS, 21 264 419CONTAMINATION, 20 109 137
262 407CONTRACEPTIVE, 323 397 411
432CONTROL, 2 104 119 132 179
193 234 235 273 385 393CONTROLLED RELEASE, 156
188 221 267 301 340 372 432CONVEYOR BELT, 313COOLANT, 11 166COOLER HOSE, 166 219 392COOLING, 104 105 179 193 235
273 311 319 413COOLING TIME, 105CORE-PULLING, 326CORK SUBSTITUTE, 219
CORNEA, 21CORROSION RESISTANCE, 43
74 159 240 295 438COSMETICS, 110 213 293 318COST, 6 18 99 102 119 150 161
179 180 192 196 218 224 226227 234 235 237 248 260 282342 352 377 381 385 393 444445
COUNTER-ROTATINGEXTRUDER, 309
CRACK, 379 386 428CRACKING, 202 292 295 347 386
428CRANKSHAFT, 219CRASH SIMULATOR, 325CREASE RESISTANCE, 303CROSSLINK, 1 201 250 263 293
303 304 311 353 359 379 395433 439 446 449
CROSSLINK DENSITY, 51 101188 200 213 218 269 283 342356
CROSSLINKING, 18 21 39 46 5154 65 68 78 81 89 131 157 163165 173 197 200 202 209 218227 229 328 395 439 446 449
CUP, 229CURE RATE, 18 26 47 51 64 65
105 200 202 241 248 250 256342 408
CURE TIME, 2 6 26 60 129 131138 150 185 200 202 248 250263 303 311 325 353
CURING, 1 3 6 8 10 12 14 15 2526 34 40 41 47 48 49 59 65 6875 78 90 91 103 107 112 119120 124 131 132 135 138 152153 154 159 163 165 185 194200 202 235 238 244 263 270271 288 290 292 295 307 310320 325 331 339 342 346 348363 377 379 380 383 385 393395 408 411 414 431 434 435438 441 450
CURING AGENT, 1 25 26 38 3958 77 81 88 94 110 113 131 138159 162 185 188 200 202 218233 249 250 285 292 295 304331 342 363 392 396 438 446449 450
CURING SYSTEM, 120 219CURING TEMPERATURE, 17 26
47 60 64 105 120 131 138 185200 248 250 263 303 304 311325 342 353
CUSHION, 228CUSTOM MOULDING, 344
CYCLE TIME, 60 64 65 105 150173 179 185 193 224 229 234235 248 250 331 342
CYTOTOXICITY, 23 25 61 131143
DDAMP-PROOFING, 187DECORATION, 238 349 355DEFECT, 18 248 292 331 366DEFENCE APPLICATION, 295
336DEFORMATION, 105 246 247 283
292 294 310 344DEGRADATION, 4 20 129 131
138 202 205 216 217 219 240258 283 338 347 366 367 380389 394 407
DEMAND, 7 35 40 118 181 376DEMOULDING, 2 49 104 185 193
204 227 248 269 305 326 331385
DENSITY, 65 94 167 192 249 292336 338 352 408
DENTAL APPLICATION, 14 2653 143 240 247 281 286 382398
DEODORANT, 110DESIGN, 9 18 28 29 49 67 105 119
141 158 161 180 189 204 207220 234 237 238 243 264 294331 338 375 405
DEVOLATILISATION, 185 246309
DIAGNOSTIC APPLICATION, 22DIALYSIS, 263 303DIAPHRAGM, 250DIATOMACEOUS EARTH, 441DIE, 73 75 160 238 260 292 309
310 359DIE SWELL, 220 310DIELECTRIC CONSTANT, 3 5
380DIELECTRIC LOSS, 312 371DIELECTRIC PROPERTIES, 131
185 249 293 311 312 363 371380 453
DIFFERENTIAL THERMALANALYSIS, 92 239 245 402420
DIFFUSION, 15 21 82 98 142 188195 267 301 308 340 389
DIMENSIONAL STABILITY, 130138 248 263 272 281 303 305311 331 348 353 398
DIPPING, 304 357DIRECT EXTRUSION, 327
Subject Index
156 © Copyright 2001 Rapra Technology Limited
DIRECT INJECTION, 173 193DIRECTIVE, 262DISC DRIVE, 306DISPERSION, 74 76 276 284 293
357 449DISPLAY DEVICE, 289DIVING MASK, 227DO-IT-YOURSELF, 226DOMESTIC EQUIPMENT, 26 54
79 194 226 238 368 391DOOR, 88 238 362 422DOOR SEAL, 219DOPANT, 312 379DOSING, 104 227DRUG DELIVERY, 98 100 184
188 267 271 301DUAL HARDNESS, 119 179DUCT, 352DUMMY, 118 192 250 263 303
304DURABILITY, 68 243 269 367
381 395 412 417 437 439DYNAMIC MECHANICAL
PROPERTIES, 310 428
EEARPLUG, 263 303ECONOMIC INFORMATION, 7
35 40 60 77 89 99 103 118 148161 179 181 185 226 235 255257 376 377 445
ELASTICITY, 4 5 18 21 25 84 90131 138 159 167 185 237 271292 294 311 379 395 433
ELECTRICAL APPLICATION, 2026 33 41 55 59 72 73 77 84 96106 112 114 159 194 209 215219 222 238 249 250 255 257289 290 311 313 333 334 343353 354 363 405 431 445 453
ELECTRICAL CONDUCTIVITY,67 127 165 218 229 250 263275 289 303 311 312 353
ELECTRICAL CONNECTOR, 2760 211 219 311
ELECTRICAL INSULATION, 3 517 20 26 41 67 73 102 109 112118 137 159 163 173 181 189219 249 255 293 313 332 343363 380 381 388 390
ELECTRICAL PROPERTIES, 3 517 20 26 41 56 65 73 78 91 109112 118 127 131 148 159 163173 179 181 185 218 219 222235 248 249 250 263 274 275290 293 303 311 312 348 353
363 371 377 380 425 431 436437
ELECTROLUMINESCENCE, 36209 212 354
ELECTROMAGNETIC SHIELD,336
ELECTRON BEAM, 346ELECTRON BEAM CURING, 8
363 372 434ELECTRONIC APPLICATION, 1
3 5 7 8 36 52 54 59 72 74 79 8486 116 194 232 238 244 250257 263 270 274 277 290 303311 329 336 339 348 353 364369 377 378 380 390 391 400453
ELONGATION, 63 65 68 90 129131 157 167 200 202 218 219228 235 248 249 291 295 342345 408 441
ENCAPSULATION, 74 184 270274 293 329 391 400 417 453
ENDOSCOPE, 100ENERGY CONSUMPTION, 13 81
173 200 248 342ENGINE, 13 159 219 223 319 321
327 335ENGINE MOUNTING, 11ENGINE OIL, 291ENGINEERING APPLICATION,
14 65 238 439ENVIRONMENT, 103 263 282
303 353 377ENVIRONMENTAL
RESISTANCE, 137 389 417EPOXY RESIN, 12 19 138 305
328 329 331 351 390 415ESTRADIOL, 340ETCHING, 164 295 312ETHYLENE OXIDE, 131 239ETHYLENE-PROPYLENE-
DIENE TERPOLYMER, 18 20109 219 367 408
EXHAUST SYSTEM, 11 60EXPOSURE LIMIT, 208 304EXPOSURE TIME, 131 202 208
217 219EXTRACTION, 69 200 271 304EXTRUDATE, 292 310 401EXTRUDER, 73 160 246 309 310
359 411EXTRUSION, 7 14 26 49 54 85 91
101 108 151 159 160 171 185200 201 230 238 246 249 276285 292 309 310 321 327 359363 401 413 431 441
EXTRUSION MOULDING, 162
EYE DAMAGE, 21 80
FFABRIC, 14 25 42 63 161 168 313
364 378FABRIC REINFORCED, 319FABRICATION, 75 91 141 271
354 425FACE MASK, 325FAILURE, 66 105 111 122 189 295
327 366FAST CURING, 26FATIGUE, 28 219 252FEEDING, 104 160 201 248 295
374FIBROBLAST, 186 198 239 283FILLER, 14 25 26 37 38 41 46 58
64 65 76 81 85 92 105 109 113127 131 137 138 162 165 167183 185 189 191 201 202 218219 222 238 246 250 255 256276 292 295 304 325 329 331363 371 384 391 392 394 439444 446 450
FILM, 3 8 32 39 42 44 168 206 236238 300 312 319 377 394 399440
FINISHING, 181 237 385FINITE ELEMENT ANALYSIS,
28 246 294 310 326FIREPLACE, 422FLAME RETARDANT, 33 219
222 232 238 276 311 352 371381 394 453
FLAMMABILITY, 25 26 185 192215 219 222 238 248 249 263276 303 311 313 319 342 353362 363 371 394 407 436 453
FLASH, 104 227 400FLASH REMOVAL, 269 385 441FLASHLESS, 2 185 202 234 248
311 326FLEXIBILITY, 15 25 64 65 105
118 194 219 227 229 237 248249 313 319 343 348 352 364373 409 423
FLEXURAL PROPERTIES, 56105 190 237
FLOW, 18 58 132 200 220 236 246292 307 309 310 331 342
FLOW RATE, 179 200 246 271307 309
FLUE, 77FLUID, 38 45 202 211 246 271
293FLUID RESISTANCE, 202FLUOROELASTOMER, 34 77
Subject Index
© Copyright 2001 Rapra Technology Limited 157
127 219 249 258FLUOROSILICONE RUBBER, 77
127 148 185 238 248 294 336377 430 437
FOAM, 14 88 94 136 192 238 251285 318 319 350 352 381 387389 392 394 436
FOAM-IN-PLACE, 99 136FOGGING, 303FOOD-CONTACT
APPLICATION, 25 26 54 185215 218 229 255 262 304 313407 408
FOOTWEAR, 228 345 408FORM-IN-PLACE, 339FORMULATION, 46 90 103 166
189 222 241 264 287 340 381395 430 431 444 448 450
FRACTURE MORPHOLOGY, 20133 186 208 231
FREE RADICAL, 75 131 250FRICTION PROPERTIES, 35 103
145 218FUEL HOSE, 77FUEL RESISTANCE, 77 148 159FUMED SILICA, 92 219 251 446FURNITURE, 14 103
GGAMMA-IRRADIATION, 131GAS INJECTION MOULDING,
18 102 132 238 285GAS PERMEABILITY, 21 138
264 313 418GASKET, 13 35 38 48 81 95 118
136 150 181 196 202 219 223256 269 285 291 294 306 324336 339 367 368 383 392 412
GATE, 104 119 227 229 307 311331
GEL, 21 26 27 66 84 101 110 111114 122 151 159 178 188 195199 203 213 217 218 238 270274 296 318 322 358 380 387389
GLASS, 12 14 138 334 394 422GLASS FIBRE, 14 62 150 238 364
374 379 385 400 417GLASS TRANSITION
TEMPERATURE, 131 245 316329 363 379 380 400 443 448
GLAUCOMA, 57GLAZING, 138 226 324 368 394
408GLOSS, 14 103GRANULE, 26 304GREASE RESISTANCE, 249
GREEN STRENGTH, 160 295GRINDING, 200 218GROMMET, 219 294 380GROWTH RATE, 7 40 48 77 102
103 118 185 226 336 368GUN, 305
HHAIR CONDITIONER, 452HARDNESS, 14 26 65 90 95 105
107 114 129 131 138 157 160179 182 185 194 202 207 218219 227 229 235 248 249 263291 292 294 303 311 331 353364 383 393 408
HEAD REST, 14HEALTH HAZARD, 14 25 66 111
131 143 185 192 203 208 210259 271 318 322 323 350 389390 407
HEART VALVE, 28 128HEAT AGEING, 65 177 202 219
249 269 383 392HEAT CURING, 14 15 25 26 40 48
78 120 131 138 159 163 185235 238 244 255 292 310 313363 368 379 383 392
HEAT INSULATION, 55 118HEAT RESISTANCE, 7 11 14 15
25 26 46 48 50 60 64 77 90 105118 121 126 129 131 138 148159 169 179 185 194 202 218219 227 229 235 248 250 263269 290 291 293 295 303 311313 329 343 353 363 380 385391 392 412 422 437 445
HEAT SHIELD, 303 313HEATER HOSE, 392HERMETIC SEAL, 121 126 270
293HIGH-PERFORMANCE, 82 303
377 378HIGH TEMPERATURE, 196 249
269 412 413 448 449HIGH VOLTAGE APPLICATION,
41 189 219 222HINGE, 331 373HIP JOINT, 344HISTOLOGY, 172 266 361HISTORY, 90 139 140 148 363 376
446HOLDING PRESSURE, 64 105HOLDING TIME, 227 229HOLLOW ARTICLE, 18HOSE, 18 77 123 149 159 166 171
219 319 335 368 392 413HOT CURING, 14 15 25 26 40 48
78 120 131 138 159 163 185235 238 441
HOT MELT ADHESIVE, 377HOUSEWARES, 54 79HYDRAULIC, 150 248 311 326
385HYDROGEL, 21 264 370HYDROLYSIS, 5 138 177 191 205
216 217 328 363 389 439HYDROLYTIC STABILITY, 21
185 205HYDROPHILIC, 21 184 188 264
419 423HYDROPHOBIC, 20 21 89 137
138 188 189 218 236 293 389423
HYDROSILYLATION, 3 56 65 75202 363 396
HYDROTHERMAL STABILITY,338 415
HYPODERMIC SYRINGE, 115
IIMMERSION, 202 269 379 383IMMUNOLOGY, 22 298 299 300IMPACT PROPERTIES, 14 25 56
189 276 325IMPLANT, 4 28 31 57 66 69 80 87
111 122 131 172 195 198 199203 210 216 217 229 239 266279 280 283 296 297 298 299300 314 315 322 323 338 340350 358 361 366 373 384 389397 399 409 432
IMPRESSION MOULD, 53IN-VITRO, 57 217 268 278 296
298 389IN-VIVO, 69 87 143 217 296 298
389INDOMETHACIN, 267INDUSTRIAL APPLICATION, 72
140 148 352 377INDUSTRIAL ROBOT, 2 150 193
326INERT, 7 68 300INFLAMMATION, 268 297INFLATABLE, 25 176 358INFLATION PRESSURE, 294INHIBITOR, 157 331INJECTION COMPRESSION
MOULDING, 14INJECTION MOULD, 2 104 105
150 185 193 248 250 263 265295 303 304 307 311 325 326342 353 363 385 391 405
INJECTION MOULDING, 2 7 911 14 15 18 26 47 49 60 64 65
Subject Index
158 © Copyright 2001 Rapra Technology Limited
77 79 83 89 91 95 97 102 104105 118 125 129 132 150 154157 159 163 165 169 173 179180 181 185 190 193 202 204207 219 223 224 229 234 235238 243 251 257 260 261 282290 329 344 348 349 355 364378 385 414 441
INJECTION MOULDINGMACHINE, 2 9 67 79 102 119193 223 227 260 273 341 374
INJECTION PRESSURE, 65 173202 229 248 250 305 326
INJECTION TRANSFERMOULD, 295
INJECTION UNIT, 2 119 150 193235 273
INSERT, 2 150 194 295 331INSERT MOULD, 11 60 64 65 89
105 150 238 248 250 295INSERT MOULDING, 2 26 150
185 229 369INSOLE, 228 345INSULATION, 20 26 41 55 96 118
224 334 453INTEGRATED CIRCUIT, 8 232
270 329 380INTERFACIAL ADHESION, 105
429INTERNAL COMBUSTION
ENGINE, 13INTRAOCULAR LENS, 16IRON OXIDE, 38 81 129 157 219IRRITANT, 131
KKEY, 116KEYBOARD, 116 238 243 250
263 303 311 353KEYBOARD MAT, 234 243KEYPAD, 1 52 163 179 219 224
303 369
LLACQUER, 390LAMINATE, 65 349 355 381 400
417LAPAROSCOPE, 100LARGE-COMPONENT, 67 193LATEX, 7 100 102 293 304LAWSUIT, 210 322 323LEAD TIME, 60 83 341LEAKAGE, 137 195 269 274 298LEGISLATION, 103 111 131 242
262 304LENS, 16 21 238 419
LEVONORGESTREL, 323 397432
LIFETIME PREDICTION, 271LIGHT DEGRADATION, 26 312
363 394 437LIGHT-EMITTING DIODE, 36
212 354LIGHT RESISTANCE, 26 185 248
250 311 380LIGHT TRANSMISSION, 107 116
182LIGHTING APPLICATION, 238LIGHTNING CONDUCTOR, 67LIMITING OXYGEN INDEX, 249LINING, 149 228LIPID, 21 195 217LIQUID CASTING, 295LIQUID INJECTION
MOULDING, 7 15 65 89 91 9597 102 104 159 179 180 185193 202 219 223 235 238 243248 250 263 282 295 303 304311 326 341 342 353 363 368369 385 405
LIQUID POLYMER, 95 97 132154 207 214 284 339 355 400
LIQUID RUBBER, 11 15 18 26 4047 49 51 54 60 64 65 67 77 7989 102 104 105 118 119 132138 157 159 161 163 173 179182 185 193 202 204 219 224227 229 234 238 241 243 248250 255 257 260 263 273 282295 303 304 311 313 326 342348 349 353 363 369 374 378385 387 405 414 441 444 449
LITHOGRAPHY, 71 141 312LONG-TERM, 20 21 34 45 274LOW TEMPERATURE CURING,
377LOW TEMPERATURE
PROPERTIES, 15 77 118 179219 227 235 248 249 287 291313 380 422
LOW TEMPERATURERESISTANCE, 219
LOW VISCOSITY, 104 138 204227 248 250 257 348
LUBRICANT, 24 38 82 115 159202 293 363 392 423
LUMINESCENCE, 36 209
MMACHINERY, 2 9 14 25 51 62 67
73 79 102 104 105 119 150 160179 182 185 193 194 223 227229 234 235 237 246 248 250
260 305 307 309 310 311 320325 326 327 331 342 355 359385 393 405
MACHINING, 237MACROPHAGE, 217 239 278 389MAGNESIUM OXIDE, 38 81 219MAGNETIC PROPERTIES, 217
293MAGNETIC RESONANCE
IMAGING, 174MANDREL, 34 310MANIFOLD, 326 367MANNEQUIN, 192 325MARINE APPLICATION, 72MARKET, 99 161 185 259 329 368
377 413 445MARKET GROWTH, 181MARKET SHARE, 40 77 89 103
179 226 235 255 336 368MASK, 325MASTERBATCH, 26 131MATERIAL REPLACEMENT, 7
30 42 94 100 102 116 134 156224 234 242 243 282 330 404409 410
MATERIALS SELECTION, 91146 149 168 352
MAXILLO-FACIAL SURGERY,167
MECHANICAL PART, 150 159185 202 219 250 255 263 269293 294 295 303 311 353 363380 383 385 392
MECHANICAL PROPERTIES, 47 14 15 17 18 21 24 25 26 2834 35 42 50 53 56 63 64 65 6977 78 84 89 90 91 92 93 94 9597 101 103 105 106 108 114118 119 124 125 129 130 131134 138 145 154 157 159 160161 166 167 174 179 184 185189 190 194 200 202 205 207214 218 219 221 227 228 229233 235 237 241 243 246 247248 249 250 252 257 263 265269 276 283 286 287 291 292294 295 303 304 306 307 310311 312 313 319 325 329 331334 342 343 345 347 348 352353 363 364 367 373 375 379380 381 382 383 389 392 393394 395 398 425 433 436
MEDICAL APPLICATION, 4 7 2122 23 24 25 26 28 29 30 31 3940 54 57 60 61 64 66 68 69 7179 91 100 106 115 128 131 133142 146 147 152 156 163 168170 172 174 176 178 180 183
Subject Index
© Copyright 2001 Rapra Technology Limited 159
185 186 188 197 203 205 206208 210 215 217 225 228 229250 254 255 257 263 264 265266 271 280 283 293 296 302303 308 311 314 315 323 330337 340 341 343 345 353 357360 361 363 364 370 373 378384 387 389 397 407 411 416431 435 444 445
MEDICAL EQUIPMENT, 83 100158 176 262 353
MELT TEMPERATURE, 104 307309
MELT VISCOSITY, 292 307 316329
MEMBRANE, 11 15 71 118 159185 188 243 263 294 311 402418 419
METAL ADHESION, 60 65 77 338METAL COATING, 336METAL FILLER, 41 218 336METAL INSERT, 150 194 250 295
331METAL REPLACEMENT, 14 391METERING, 9 89 229 243 321MICROMOULDING, 9 164MICROWAVE HEATING, 254MIGRATION, 15 20 21 66 82 103
137 195 217 298 300 304 389407
MILITARY APPLICATION, 96295 319 430
MILLING, 65 163 255 357MINERAL FILLER, 26 55 185 202
238 329 363 391MIXER, 157 311MIXING, 1 14 26 46 89 171 181
185 194 200 202 227 229 235246 248 250 287 291 309 311392 393 413 414 441
MOBILE PHONE, 60MODULUS, 131 200 219 249 269
291 295 450MOISTURE CURING, 6 138 363
408MOISTURE RESISTANCE, 137
159 185 274 377MOLECULAR STRUCTURE, 5 8
21 26 36 65 72 91 112 131 135138 163 177 185 187 195 200212 219 239 245 249 250 255267 292 312 316 328 346 363394 395 406 426 434 436 437446 447 448 450
MOLECULAR WEIGHT, 21 26 6568 69 138 152 185 195 200 213280 289 293 356
MOONEY VISCOSITY, 292MORPHOLOGY, 20 133 186 208
231 239 245 406MOTOR CYCLE, 19MOULD, 2 104 105 107 150 185
193 194 204 234 235 237 248250 257 272 288 307 311 320325 326 331 342 344 359 385393 398 405 423 431
MOULD CAVITY, 117 190 331MOULD CLOSING, 150 248MOULD COOLING, 193MOULD CYCLE, 150 185 193
248 250 331MOULD DESIGN, 9 18 49 67 105
204 243 331 344 405MOULD FILLING, 47 64 104 105
119 190 193 227 229 307 331MOULD FLOW, 257 307 331 342MOULD HEATING, 49 193 260
263 303 311 331MOULD INSERT, 83 331MOULD MAKING, 57 102 317MOULD RELEASE, 58 60 89MOULD RELEASE AGENT, 40
58 113 331 363 423MOULD SLIDE CORE, 65MOULD TEMPERATURE, 64 65
89 104 105 118 119 150 193202 207 211 227 229 248 250304 307 342 344 353
MOULDING, 9 10 14 16 18 19 2134 40 54 56 57 58 60 62 77 8291 107 154 162 163 164 179185 190 192 200 202 211 214231 234 270 288 290 304 311331 337 342 363 369 398 431
MOULDING COMPOUND, 58170 288 342 380 391 400 453
MOULDING FAULT, 248MOULDING PRESSURE, 47 190
248 250 307 326 414MOULDMAKING, 57 102 288
317 331 348MOULDS OF POLYMERS, 12 26
45 62 138 153 164 175 182 190194 237 272 288 305 320 331344 393 410
MULTI-CAVITY MOULD, 204248 250 311 342 385
MULTI-COMPONENT, 2 9 26 6479 105 132
MULTI-MATERIAL MOULDING,2 102 105
MUTAGEN, 389 399MYOSITIS, 297NANOSTRUCTURE, 231
NNATURAL RUBBER, 35 64 146
149 234 243 304NEOPRENE, 42 149 161NERVE REGENERATION, 283NIP GAP, 34NIPPLE, 37 163 224 227NITRILE RUBBER, 102 105 149
219NITROSAMINE, 304 407NITROSAMINE-FREE, 37NOISE REDUCTION, 319 367NON-ALLERGENIC, 173NON-RETURN VALVE, 273NON-STICK, 7NON-TOXIC, 25 173 229 303 311NOZZLE, 193 234 235 243 260NUCLEAR MAGNETIC
RESONANCE, 174 216 217245 253 267 280 420
NYLON, 14 25 60 64 89 105 125132 150 161 211 238 255 410
OO-RING, 77 95 269 303 327 368
386ODOUR-FREE, 303OFF-THE-ROAD VEHICLE, 124OFFICE EQUIPMENT, 89 219 306OFFSHORE APPLICATION, 185
352OIL PAN GASKET, 219 269 383
392 412OIL RESISTANCE, 11 60 77 148
159 191 202 219 249 269 287291 380 383 385 445
OIL SEAL, 202 347OLIGOMER, 304 309 328 329 346
363 423 447ONE-COMPONENT, 14 26 138
157 159 250 311 313 342 394400 408 409 422 439 446 449450 453
OPTIC FIBRE, 379OPTICAL APPLICATION, 12 16
21 36 57 264 277OPTICAL PROPERTIES, 14 21 22
25 56 131 141 185 194 202 212218 229 237 248 263 292 293295 303 312 331 353 379
OPTOELECTRONICAPPLICATION, 36 386
ORGANOLEPTIC PROPERTIES,213
ORGANOSILICONE POLYMER,9 16 21 27 37 38 40 43 55 59
Subject Index
160 © Copyright 2001 Rapra Technology Limited
66 70 75 78 84 85 86 87 88 9093 94 97 103 110 113 114 121122 123 124 126 134 135 140142 143 151 154 156 166 168179 195 197 199 203 205 206207 208 209 210 220 226 230232 233 238
OUTGASSING, 77 121 126 331437
OVEN CURING, 25 26 185 200202
OVERMOULDING, 11 60 64 6589 105 150 238
OXIDATION, 141 217 278 314437
OXIDATION RESISTANCE, 26185 293
OXIDATIVE DEGRADATION,141 217 278 314 437
OXIME, 450OXYGEN INDEX, 249OZONE RESISTANCE, 26 35 65
248 250 293 311 343 363 380437
PPACKAGING, 86 270 400 408PAD, 228 345PAINT, 237 390 408 448PAINTABILITY, 90PAPER COATING, 25PARTING LINE, 45 194 331PASTE, 248 250 295 422PATENT, 176 179 192 376 382PEEL STRENGTH, 64 90 105 261
440PELLET, 54 211PENTASILICIC ACID, 216PERFLUOROELASTOMER, 77PERMEABILITY, 21 138 177 264
267 418 419PERMITTIVITY, 371PEROXIDE, 1 26 101 138 157 159
185 200 218 222 241 250 292295 342 363 377 392 446 449
PEROXIDE VULCANISATION,46 67 138 159 163 185 200 218250 271 291 292 295 396
PHARMACEUTICALAPPLICATION, 25 98 131 184188 221 267 293 301 340 402416
PHENYLSILICONE RESIN, 381PHOTOCONDUCTIVITY, 312PHOTOCROSSLINK, 14 107 182
346 442PHOTODEGRADATION, 312 437
PHOTOINITIATOR, 312 346 442PHOTOLITHOGRAPHY, 71 141PHOTORESIST, 12 141 277 312
442PHOTOSENSITISER, 59 346PHYSICAL PROPERTIES, 45 58
69 112 177 222 239 241 244364 384 394 417 426 434 439445 453
PHYSICOCHEMICALPROPERTIES, 183 221 300
PHYSICOMECHANICALPROPERTIES, 68 152
PIGMENT, 14 194 248 249 250255 295 311
PIPE, 352PIPE LINING, 149PISTON, 2 150PLASMA TREATMENT, 21 141
419PLASTICISATION, 104 385PLASTICISER, 127 131 185 255
304 408PLATELET ADHESION, 39PLATINUM, 1 3 10 26 33 51 88 94
95 97 138 157 185 195 202 232241 250 304 331 342 346 377434
PLATINUM CURING, 46 241 271PLUG, 27 67PLUNGER, 385 401POLYADDITION, 64 129 143 213
423POLYAMIDE, 14 25 60 64 89 105
125 132 150 161 211 238 295314 410 448
POLYBUTYLENETEREPHTHALATE, 60 64 105229 238 261
POLYCARBONATE, 14 237 238261
POLYCARBORANE SILOXANE,371
POLYCARBOSILANE, 56 155312
POLYCARBOSILOXANE, 72POLYCHLOROPRENE, 42 149
161 249 394POLYCONDENSATION, 85 143
191 423 435 446POLYCYCLOSILOXANE, 85POLYDIBUTYLPHENYLSILANE,
36POLYDIETHYLSILOXANE, 420POLYDIHEXYLSILANE, 312POLYDIMETHYL SILOXANE, 4
21 22 31 32 92 98 101 103 115131 137 141 178 183 186 197
200 202 203 213 214 216 217221 225 231 245 246 256 267280 283 292 293 299 300 309316 397 428
POLYDIMETHYLPHENYLSILOXANE,371 435
POLYEPOXIDE, 12 19 138POLYETHYLENE, 14 128 237
249 287 314 344 377 394POLYETHYLMETHYLSILOXANE,
418POLYFLUOROSILOXANE, 21POLYIMIDE, 177 265 417 448POLYMERISATION, 4 56 78 85
90 129 155 184 272 293 312363 390 425
POLYMETHYLMETHACRYLATE, 14 231 278305 344
POLYMETHYLOCTYLSILOXANE,418
POLYMETHYLPHENYLSILOXANE, 293
POLYMETHYLPHENYLSILANE,36 212 354
POLYMETHYLPHENYLSILOXANE,418
POLYMETHYLPHENYLSILYLENE,406
POLYMETHYLPROPYLSILOXANE,418
POLYMETHYLSILOXANE, 152380 433
POLYMETHYLTRIFLUORO-PROPYLSILOXANE, 418
POLYMETHYLVINYLSILOXANE, 396
POLYORGANOSILOXANE, 4 916 21 22 27 31 32 37 38 40 4355 59 66 75 78 84 85 86 87 9092 93 94 97 98 101 103 110 113114 115 121 122 123 124 126134 135 140 142 143 151 154156 165 166 168 179 195 197199 203 205 206 207 208 209210 220 226 230 232 233 238285
POLYPHENYL SILOXANE, 380POLYPHENYLENE ETHER, 64
238POLYPHENYLENE OXIDE, 238POLYPHENYLENE SULFIDE,
400POLYPHENYLENE VINYLENE,
354POLYPHENYLMETHYL
SILOXANE, 437 447POLYPROPYLENE, 237 265 349
Subject Index
© Copyright 2001 Rapra Technology Limited 161
377POLYSILETHYLENESILOXANE,
418POLYSILHEXYLENE
SILOXANE, 418POLYSILOXANE ACRYLATE, 21POLYSILOXANE-URETHANE,
21POLYSTYRENE, 87 133 237 238
245 293POLYSULFIDE, 14 408 422POLYTETRAFLUOROETHYLENE,
35 82POLYTRIFLUOROPROPYL-
METHYLSILOXANE, 437POLYURETHANE, 14 21 30 52 99
100 133 134 136 138 146 152192 206 226 231 268 305 306314 318 319 325 328 331 341350 351 352 358 381 389 390394 408 421 422
POLYURETHANE ELASTOMER,138 139 239 389
POLYVINYL CHLORIDE, 6 14100 146 249 268 314
POLYVINYL SILOXANE, 14 53POLYVINYLPYRROLIDONE,
370POROSITY, 3 168 172 218 283
331 361POST CURING, 26 64 105 185
200 202 218 248 304 331 342363
POST FORMING, 319POT LIFE, 89POTTING, 59POTTING COMPOUND, 293 380
400 417 453POWER TRANSMISSION, 137PRECIPITATED SILICA, 292PRECISION MOULD, 190 202
326 405PRECURING, 200PRECURSOR, 13 16 312 426PREFORM, 117PREHEATING, 2 331PREPREG, 400PRESSURE, 34 104 157 190 193
200 202 227 246 269 292 294307 309 310 344 428
PRESSURE CONTROL, 229PRESSURE RESISTANCE, 218
269PRESSURE SENSITIVE, 121 126
275 372 377 380 423 429 434435
PRICE, 7 11 77 102 179 341 400445
PRIMER, 421 422 435PRIMERLESS, 65PRINTED CIRCUIT, 380 390 400PRINTING, 116 238 442PROCESSABILITY, 18 48 65 77
100 118 246 381PROCESSING, 12 18 25 26 46 67
79 91 99 120 131 148 163 169181 185 192 207 237 241 244250 251 255 257 263 295 303311 348 353 364 376 379 382401 416 446
PROCESSING AID, 304PRODUCT ANNOUNCEMENT, 9
13 27 102 156 176 180 192 196243 257 284 306 330 337 339349 355 362 369 373 378 382386 387 390 400 404 408 409411 421 436
PRODUCT DESIGN, 28 119 189234 237 257 294 331
PRODUCT DEVELOPMENT, 1118 60 126 237
PRODUCTION, 148 180 255 453PRODUCTION COST, 18 150 224
235 237 243 248 342PRODUCTION RATE, 60 263 305
310PRODUCTIVITY, 54 150 175 179
220 243 248 257 342 445PROFILE, 151 185 292 359 363PROSTHESIS, 14 26 57 61 122
142 152 167 217 236 250 286296 344 356 361 366 389
PROTECTIVE CLOTHING, 25263 303 311 313 353 364 378
PROTECTIVE COATING, 43 187390 426 453
PROTEIN, 86 217 283 293 389PROTOTYPE, 26 83 141 175 180
193 194 237 320 325 331 341344 393
PSEUDO GEL, 142PULL STRENGTH, 16PUMP, 229 235 271PURITY, 77 271 329 453PUTTY, 170 254 302 337 398PYROGENIC, 157PYROLYSIS, 177 312 407 426
QQUALITY, 54 126 132 150 168
234 241 262 263 273 310 353364 378 386 413 445
QUARTZ, 14 162 441QUICK COLOUR CHANGING, 2QUICK MOULD CHANGING, 326
RRACING CAR, 412RADIATION CROSSLINKING,
59 68 103 250 396 434 449RADIATION DEGRADATION,
131RADIATION RESISTANCE, 313
343 352RADIATION STERILISATION, 7
131RADIATOR, 159RADIOIMMUNOASSAY, 268RAILWAY, 72 375 408RAPID PROTOTYPING, 26 83
305RAPID TOOLING, 83 237REACTION INJECTION
MOULDING, 251 341RECYCLING, 161 200 255 263
282 303 311 349 353 364 377385
RED IRON OXIDE, 157REFRACTIVE INDEX, 45 312REFRIGERATOR, 238REGULATION, 77 242 304 322
390 416REINFORCED PLASTIC, 14 19
142 150 153 183 196 210 238240 245 317 319 323 335 336337 360 374 382 385 391 400410 417
REINFORCED RUBBER, 13 50106 158 295 357
REINFORCEMENT, 58 150 256425 444 446
REJECT RATE, 126RELEASE AGENT, 40 58 82 113
140 372RELEASE COATING, 372 377
428 429 434RELEASE PROPERTIES, 168 218
377 423REPLICATION, 12 164 231REPRODUCIBILITY, 98 104 193RESIDENCE TIME, 200 309RESILIENCE, 108 131 218 243
342RESISTIVITY, 65 127RESTORATION, 138 443RETARDER, 53REVIEW, 9 43 46 50 70 78 80 90
91 94 102 120 122 127 129 139140 144 145 146 148 149 155177 187 241 245 253 258 264277 293 297 298 299 316 328346 351 352 365 369 372 376377 381 388 389 394 395 396
Subject Index
162 © Copyright 2001 Rapra Technology Limited
406 407 414 415 417 418 419420 421 422 423 425 426 427428 429 430 431 432 433 434435 436 437 439 440 441 442443 444 445 446 447 448 449450 451 452 453
RHEOLOGICAL PROPERTIES,10 14 18 25 26 49 51 53 65 7782 104 105 115 119 138 142157 160 161 173 184 191 200213 220 246 248 250 292 293307 309 310 316 331 342 363380 417 420 425
RHEOMETRY, 94 157 241 246292 310 342 401
RHEUMATISM, 297RIFAMPICIN, 221RIGID, 52 64 105 190 394RING-OPENING
POLYMERISATION, 85 328406 446 451
ROBOT, 2 102 150 193 229 234325 327
ROCKER COVER, 269 321ROLLER, 34 139 160 218 219 227
306 343ROOFING, 394ROOM TEMPERATURE
VULCANISATION (RTV), 2526 38 48 81 94 138 159 164191 201 238 250 255 256 313368 380 381 392 423 439 443444 446 449
ROTATING TABLE, 150 385ROTATIONAL MOULDING, 64
105 360RUBBERISED FABRIC, 313RUNNER, 193 307 331RUPTURE, 122 142 428
SSAFETY, 271 322 331 352 362 364
407SAG FACTOR, 201SALES, 11 102 156 179 223 226
368 445SALICYLIC ACID, 188SALIVA, 14 236SALT FOG RESISTANCE, 189
295SANITARYWARE, 422SCANNING ELECTRON
MICROSCOPY, 4 61 133 172177 186 198 221 245 308 315366
SCORCH, 64 105 200 342SCRAP, 150 200 263 269 303 311
342SCRAP REDUCTION, 150 248
250 329 342SCRATCH RESISTANCE, 331SCREW, 160 193 235 246 273 309SCREW SPEED, 200 246 309SEAL, 9 15 18 27 35 38 60 76 77
81 84 95 99 119 121 123 126130 150 159 179 181 185 202211 219 223 227 235 250 269273 291 293 294 295 303 306311 321 327 336 347 352 353362 363 367 374 383 385 386392
SEALANT, 6 7 38 40 48 65 81 90114 124 127 226 255 327 339352 365 368 394 395 404 408422 430 437 438 439 450 453
SEALING, 9 84 324 343 352 383SEALING STRIP, 108SEAT, 14SELF-ADHESIVE, 11 25 26 65 89SELF-EXTINGUISHING, 238 248SELF-LUBRICATING, 15 60 159
185 248 250 263 303 311SEMI-FLEXIBLE, 62SEMICONDUCTOR, 5 75 77 312
329 380SENSITISATION, 131SENSOR, 32 159 275SERVICE LIFE, 6 28 35 166 173
175 189 218 219 269 272 291331 338 347
SERVICE TEMPERATURE, 77SHEAR, 84 89 124 157 200 246
292 294 310 420SHEAR RATE, 184 200 246 292
307 310SHEATH, 62 147SHEET, 55 200SHEET MOULDING
COMPOUND, 14SHELF LIFE, 89 218 342SHELL, 152 195SHIELDING, 337SHIP, 72SHOCK ABSORBER, 159 284 375
392SHORE HARDNESS, 107 129 182SHORT PRODUCTION RUN, 320
341SHOT CAPACITY, 150 374SHOT WEIGHT, 193 273SHOWER, 60 422SHRINKAGE, 12 14 90 157 162
272 305 329 331 348 398SILANOL GROUP, 85 138 211SILICA, 14 33 58 92 95 106 112
131 138 157 162 167 185 202217 218 219 222 245 251 256276 292 363 391 392 395 408423 441 444 446
SILICON CARBIDE, 312 426SILICON-29, 217SILICONE COPOLYMER, 21 88
115 264 351 387 444 452SILICONE OIL, 15 25 26 80 213
363 392 395SIMULATION, 105 132 178 246
292 304 310 325SINGLE-COMPONENT, 14 26
138 157 159SLIP, 246SMALL-COMPONENT, 159 193
248 263 303 311 353 364SMOKE, 26 185 249 352 381SNAP-FIT, 77SOCKET, 344SOFT CONTACT LENSES, 21SOFT-TOUCH, 103SOFTWARE, 83 180 220 294 307
325SOLAR CELL, 417SOLUBILITY, 21 177 217 293 309
363 425SOLUTION CASTING, 360SOLVENT, 21 69 155 356 443SOLVENT EXTRACTION, 69 200
304SOLVENT RESISTANCE, 148 356SOLVENTLESS, 25 161 377 390
408 434SOUND ATTENUATION, 196SOXHLET EXTRACTION, 101
200SOYABEAN OIL, 195SPACE APPLICATION, 417SPARK PLUG, 219 235 250 392SPIN CASTING, 175SPORTS EQUIPMENT, 194 311SPRAYING, 62 288 295 357 408SPREADING, 352SPRUE, 331SPRUELESS, 9STABILISER, 157 250 293 304STABILITY, 21 46 90 121 126 129
148 159 185 202 205 352 357381 395
STANDARD, 34 93 96 157 161262 304 319 324 332 333 334335 353 362 365 377 383
STAPHYLOCOCCUS, 236 278STATIC, 218 375STATIC MIXER, 305 311STATISTICS, 7 35 40 50 77 90 102
118 148 161 179 181 185 226
Subject Index
© Copyright 2001 Rapra Technology Limited 163
255 257 368 413 445STEAM CURING, 26STEEL, 295 422STEERING WHEEL, 11STERILISATION, 7 131 239 311
389STICK-SLIP PROPERTIES, 440STRAIN, 200 236 294 295STRENGTH, 17 50 53 65 94 129STRESS, 28 50 92 189 246 283
294 310 329 379 437STRESS RELAXATION, 114 219
269 310 383STRESS-STRAIN PROPERTIES,
174 200 294SUBCUTANEOUS, 399SULPHUR VULCANISATION,
304SURFACE CRACKING, 292SURFACE DEGRADATION, 137SURFACE ENERGY, 65 103 137
189SURFACE FINISH, 87 103 218
237 248 273SURFACE PROPERTIES, 20 61
64 68 71 105 128 172 186 206214 218 239 292 300 425 437453
SURFACE TREATMENT, 21 4189 135 211 237 238 295 331363 370
SURFACTANT, 53 90 103 293SURGICAL APPLICATION, 4 14
31 100 111 122 131 134 135146 152 167 195 198 199 216236 239 242 253 259 266 279296 300 318 338 344 350 358366 387 389 397 407 409 411416 425 431 435 444 445
SURGICAL TUBING, 100 131250 384
SWELLING, 21 69 90 101 157 188200 202 213 256 287 291 295310 356 380 383
SWITCH, 11SYNTHESIS, 85 155 184 197 258
264 316 328 346 351 357 376406 424 426 439 444 446 447
SYNTHETIC LEATHER, 325SYNTHETIC RUBBER, 90 96 101
120 165SYRINGE, 115 263 303 311 353
TTACK, 17 114 228 342 345TAKE-OFF SYSTEM, 273TAKEOVER, 40 223 368
TALC, 162TAPE, 96 377TEAR STRENGTH, 25 53 63 65
77 93 131 138 161 162 167 185202 218 228 248 249 250 269291 295 331 342 345 433 444
TEAT, 37 163 224 227 304 311 353TELECOMMUNICATIONS
APPLICATION, 194 238 336TELESCOPE, 417TELEVISION, 194 222 238TEMPERATURE CONTROL, 2
104 158 193 273 303 342TEMPERATURE DEPENDENCE,
47 50 130 212 246TEMPERATURE RANGE, 35 65
173 229 255 258 319 336TEMPERATURE RESISTANCE,
67 91 189 364 377 381 394TEMPLATE, 107 182 283TENSILE PROPERTIES, 4 21 24
65 69 95 101 124 125 129 157167 174 200 202 205 218 219228 235 250 291 312 342 345363 392 394 408 422 433 441444 445
TEST EQUIPMENT, 93 94 178325 386
TEST METHOD, 65 68 93 103 137180 189 304 325
TESTING, 65 68 93 94 103 137178 180 189 217 243 244 262271 304 325 333 362 365 367386 389 390 394 395 398 399407 413 416 432 434 440
TETRAMETHYLDISILOXANEDIOL, 216
TEXTILE, 25 140 257 378 364THERMAL CONDUCTIVITY, 10
25 218 246THERMAL DEGRADATION, 65
177 202 219 389 392 394 400413 453
THERMAL EXPANSION, 248 317329 331 380
THERMAL INSULATION, 55 118319 381 394
THERMAL PROPERTIES, 25 2650 56 98 104 131 161 218 245246 247 248 258 293 295 307309 317 331 363 379 380 402425 453
THERMAL STABILITY, 7 11 1425 26 46 48 50 60 64 77 90 105121 126 129 131 138 148 159169 179 185 194 202 218 219227 229 235 248 250 258 263269 290 291 293 295 303 311
313 329 343 353 363 380 385391 392 412 422 437 445 448453
THERMOFORMING, 14THERMOLYSIS, 3 312 407THERMOPLASTIC
ELASTOMER, 62 64 102 127223 235 304
THICK-WALL, 104THICKNESS, 21 25 105 188 237
239 326 331 383THICKNESS CONTROL, 237THIN FILM, 42 44 168THIN-WALL, 104 105 238 331
357THROMBECTOMY, 176THROMBORESISTANCE, 183TIEBARLESS, 234 243 326TIN COMPOUND, 61 129 201 250
302 331 337 434TISSUE EXPANDER, 308TISSUE RESPONSE, 217 239 283
384TITANIUM COMPOUND, 59 162
278 295 415 426TOGGLE, 102 248 326TOLERANCE, 83 104 235 237
294TOOLING, 19 60 153 227 237 317TOOTH RESTORATION, 14TOXICITY, 14 25 131 143 185 192
249 263 271 303 304 352 358362 381 389 390 396 407 438
TOYS, 194 237TRACKING RESISTANCE, 219TRADE NAME, 2 14 25 26 131
159 193 202 219 238 249 250263 313 353 389 392 405
TRAFFIC CONTROL, 275TRANSDERMAL, 98TRANSFER MOULDING, 91 163
185 329 342 380 400 453TRANSLUCENT, 25 272TRANSMISSION FLUID, 202 291TRANSPARENCY, 21 103 107
131 141 185 194 202 229 232237 248 257 263 264 289 292303 305 353 364
TRANSPORT APPLICATION, 362381
TRANSPORT PROPERTIES, 298354
TREND, 100 103 339TRIMETHOXYVINYLSILANE,
408TROUBLESHOOTING, 160TRUCK, 124 413TUBING, 7 100 131 162 185 250
Subject Index
164 © Copyright 2001 Rapra Technology Limited
252 262 271 310 343 352 363387
TUMOUR, 337 399TURBOCHARGER HOSE, 413TWIN-SCREW EXTRUDER, 230
246 309TWO-COMPONENT, 9 11 15 26
42 47 53 65 89 105 125 138150 157 159 161 179 202 224227 229 238 248 250 263 303305 310 311 313 321 325 364374 378 385 393 394 422 439446 449 453
UUNDER-THE-BONNET
APPLICATION, 35 77 89 159166 185 202 219 269 291 294321 327 367 380 385 392 400427
UNDERWATER APPLICATION,158
UNSATURATED POLYESTER,138 335 374 385
UV CURING, 14 25 238 372 377379
UV RADIATION, 137 346UV RESISTANCE, 35 185 189 226
250 311 377 381 394 408
VVACUUM, 190 229 309VACUUM BAG MOULDING, 410VACUUM CASTING, 26 194 237
320 331 341 393VACUUM FORMING, 14 190VACUUM MOULD, 248VALVE, 185 385VALVE COVER, 219 269 374 385
412VANDAL PROOF, 219VARNISH, 103 140VASCULAR PROSTHESIS, 268VEHICLE DOOR, 238VEHICLE ENGINE, 159 219 269
385VEHICLE IGNITION, 219VEHICLE LIGHT, 238VEHICLE RADIATOR, 159VEHICLE SPOILER, 408VEHICLE SUSPENSION, 375VENTING, 49 190 309 331VERTICAL MACHINE, 2 102 349VIBRATION DAMPER, 159 293
367 392
VINYL GROUP, 110 200 202 211VISCOELASTIC PROPERTIES,
213 286 292 310VISCOSITY, 10 14 18 25 26 49 51
53 65 77 82 101 104 115 119138 157 160 173 184 191 200213 246 248 250 255 292 293307 310 331 363 380
VOICE PROSTHESIS, 61 236 366VOID, 112 331VOID-FREE, 341VOLATILE, 85 110 309 438VOLATILITY, 269 293 304 438VOLUME RESISTIVITY, 249 336
371VULCANISATION, 2 25 26 46 67
78 79 101 105 106 131 138 150159 162 163 171 181 185 193194 200 202 218 219 248 249250 260 263 292 295 301 303304 307 310 311 313 331 342348 353 359 363 380 383 392396 424 425 444 449
VULCANISATION TIME, 2 6 2660 129 131 138 150 185 200202 229
WWALL SLIP, 246 292WALL THICKNESS, 18 64 105
310 331 341WASHER, 150 383WASHING, 137 304WASTE, 173 200 263 271 303 311
353WATER, 20 85 188 217 236 263
303 443WATER ABSORPTION, 65 379
421 422 437 443 448 453WATER EXTRACTION, 304WATER PERMEABILITY, 138
423 443WATER REPELLENT, 72 159 187
448WATER RESISTANCE, 20 21 60
72 293 338 421 422 437 443448
WATERPROOFING, 27 138 187423
WAX, 58 110 138WEAR RESISTANCE, 14 34 42
119 145 161 218 306WEATHER RESISTANCE, 6 7 72
77 226 255 290 348 352 381394 395 422
WEATHER STRIPPING, 88 219233 367
WEATHERING, 6 72 77 249 255290 343 380 394 395 422 437443
WEIGHT LOSS, 157 293 309 398WEIGHT REDUCTION, 161 234
243 336WETTABILITY, 20 21 53 65 109WETTING, 92 103 167 264WINDOW, 88 138 238 362 422WINDSCREEN WIPER BLADE,
35 82 159WIRE, 73 112 249 332 334 368
445 453WIRING HARNESS, 319WOOD FINISH, 103WORK SURFACE, 408
XX-RAY CONTRAST MATERIAL,
119
YYIELD, 155 246 426YOUNG’S MODULUS, 4 5 21 84
167 271 292 294 379
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