5096 5100.output

* GB785503 (A)

Description: GB785503 (A) ? 1957-10-30

Improvements in or relating to the electro deposition of a metal on piecesof metal or metallic alloys

Description of GB785503 (A)

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BE542097 (A) CH335578 (A) DE1139713 (B) FR1112967 (A) NL112865 (C) BE542097 (A) CH335578 (A) DE1139713 (B) FR1112967 (A) NL112865 (C) less Translate this text into Tooltip

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PATENT SPECIFICATION 7801 Date of Application and filing Complete Specification Oct 10, 1955. No 28757155. Application made in France on Oct 21, 1954. Complete Specification Published Oct 30, 1957. Index at Acceptance:-Class 41, B(IR: IS: 4: 15 X 17). International Classification: -C 23 b. COMPLETE SPECIFICATION Improvements in or relating to the Electro Deposition of a Metal on Pieces of Metal or Metallic Alloys W 5 Ye, BOZEL-MALETRA, SOCIETE INDUSTRIELLE DE PRODUITS CIIIMIQUES, a French Body Corporate, of 38, rue de Lisbonne, Paris, France, do hereby declare the invention, for

which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - The present invention relates to a process of the kind in which a degreased surface of a metal or metallic alloy which normally bears a protective layer, usually an oxide layer, is provided with an adherent, hard coating of a metal, particularly chromium or nickel, in an acid bath for electrodepositing said metal Such coatings may be applied to the workpieces being treated with the object of conferring certain surface properties on the workpieces or to protect or decorate them. According to the metal employed and the object in view, the coatings can be made to confer on the surface of the workpieces considerable hardness, a good coefficient of friction, a high resistance to wear, oxidisation or corrosion by certain chemicals, or decorative effects The coatings can also provide surfaces which, when suitably treated by various mechanical processes or by polishing, are suitable for optical and mechanical applications, In order to obtain a good adherent coating of the electrolytic metal on the workpiece to he treated, it is necessary to remove the protective layer, generally an oxide layer, which covers the surface of the workpiece. Various processes based on the use of acidic and alkaline compounds have been proposed for removing the protective layer, but except in certain particular cases, a new layer is formed as soon as the cleaned pieces are brought into contact with water or the atmosphere When pieces cleaned in this manner are subsequently treated in an electrolytic bath, they become coated with non-adherent deposits by reason of the presence of this intermediate layer and they frequently present a number of defects (e g flaking and fissuring) lPrice 3 s 6 d l resulting from the loss of adherence on the base metal. Various means are actually used for preparing metals coated with such a layer, in particular aluminium and its alloys, in readiness for chromium plating, nickel plating or other electro-plating process Their object is to obtain a certain adherence of the deposit in the presence of the oxide layer and to make the deposit adhere to the base metal with or without the interposition of various intermediate layers. The main known processes employ one of the following techniques: A More particularly for use with aluminium and its alloys:(a) Electro-plating on to intermediate layers of zinc or other metals applied by a chemical process with or without the passage of an electric current; (b) Electro-plating on to a layer of aluminium oxide produced by an anodic oxidation treatment, this layer frequently being submitted to a chemical or electro-chemical treatment prior to

receiving the electroplating; (c) Electro-plating on to surfaces which have been cleaned mechanically, usually by means of an abrasive in suspension in a liquid which remains adhering to the workpiece and protects it against atmospheric action; (d) Electro-plating on to surfaces cleaned by means of a chemical bath containing a salt of a heavy metal which is deposited on the workpiece and is removed by being chemically dissolved before commencement of the electrolytic treatment. B More particularly in the case of metals, other than aluminium, covered with an oxide layer: (a) In the case of chromium, electroplating after anodic attack of the workpiece in the electrolysis bath by reversing the current flow in the bath; (b) In the case of stainless steels, electroplating after anodic attack of the workpiece in an acidic electrolysis bath of a special com05,3 r 23 p, 785,503 position, this attack being followed, after rapid reversal of the current, by the application of an electrolytic deposit on which is applied the subsequent electro-plating. The primary object of the present invention is to make possible the electrolytic deposition of adherent coatings of various metals, in particular chromium and nickel, on workpieces of metals or alloys which are normally protected by an oxide layer or a layer having an oxide base. According to this invention, we provide a process of the kind above set forth, which comprises the steps of subjecting the degreased metal surface to an acid etching, making said surface a cathode and subjecting the same in the metal electrodepositing acid bath to cathodic action with a current intensitv initially at a level below the minimum value for the incipient metal electrodeposition, then increasing the current intensity from said level slowly enough to reach normal current intensity for metal electrodeposition in a period of not less than five minutes. The preliminary treatment by means of which the metal surface is degreased prior to acid etching may consist of, or comprise, a mechanical abrasion treatment, for example, dry sand blasting or abrasive cleaning in a liquid medium It may also comprise, in succession, degreasing with a solvent, an electrolytic degreasing treatment or cleaning in an alkaline bath and a washing with water. For the first phase of the preliminary treatment trichlorethylene may he used as the degreasing solvent In the second phase of the treatment, the degreased workuiece is placed in a known electrolytic degreasing bath containing water in which there has been dissolved soda, sodium carbonate, an alkaline cyanide, an alkaline phosphate or other alkaline comnround of the kind normally used in baths of this type.

The bath, which may be at the workroom temperature, is provided with the usual current producing members and the workniere is connected to the negative nole The purpose of the acid etching effected after the preliminary treatment is mainly to remove thoroughly the naturally occurring thick layer of oxide on the metal surface, in order that after the acid etching followed with a water washing as will be explained below, the metal surface will become coated with a thin, freshly formed film of oxide which can easily be thoroughly destroyed in the electrolysis bath before commencement of the electro-plating process. For effecting the acid etching, hydrochloric acid, hydrofluoric acid or a mixture of these two is Preferably used These acids are suitable for attacking aluminium and the maioritv of metals which it may be desired to treat by the process according to the invention Tlowever, if it is desired to treat a metal which is not attacked, or only slightly attacked by these acids, it is necessary to replace these acids by an acid capable of attacking the metal under consideration The workpieces to be treated are, for example, simply dipped in the acid. The acids are used, with advantage, in the form of concentrated aqueous solutions Dilute or 70 very dilute solutions may, however, be convenient in certain cases. In the case of aluminium alloys containing a high proportion of silicon, excellent results have been obtained by the employment of 75 hydrochloric acid, while the employment of hydrofluoric acid appears to be even more advantageous The attack which is produced, often with a very abundant and visible evolution of gas, should not be too prolonged so as 80 not to cause the removal of an appreciable thickness of metal It may be interrupted very simply, at the anpropriate time, by washing the workpiece with water After this washing the workpiece may or may not, be coated with 85 a film, often grey or black, the presence or absence of which does not usuallv affect the remainder of the treatment The workpiece is then washed very thoroughly in water completely to remove the cleaning acid with a view 90 to avoiding corrosion of the work-piece and the introduction of the acid into the electrolysis bath During this washing a new oxide film is usually formed on the surface of the cleaned workpiece The wetted workpiece is 95 placed immediately in the appropriate electroplating bath all the necessary operations (fixing of the connections, contacts etc) being effected as rapidly as possible With a view to avoiding an increase in the thickness of 100 the oxide layer when the workpiece is placed in the bath, the operation of Placing the workpiece in the bath may be effected with the bath under current, the anodes and the workpiece being connected to the electric current

source 105 prior to introduction of the workpiece into the bath As a result the workniece is in a reducing medium at the negative pole of the bath, from the commencement of the operation This precaution which may however complicate, and 110 this retard, the placing of the workpiece in the bath; has often proved favourable It is how ever, not indispensable and may be omitted in the maiority of cases It is, however, recommended if, by reason of the dimensions or 115 shape of the wvorkpiece, its placing under current in the bath is likely to occupy a considerable time. When the workpiece is in position in the bath it is nlaced under current as rapidly as 120 possible (if it;s not already under current). This nlacing under current, which is an essential feature of the process, should be effected progressively so as to cause an evolution of hydrogen on all Parts of the workpiece, the 12 ' object of which is to reduce the oxide layer and thus to eliminate the protective layer before the commencement of the electroplating process The current established at the commencement should have as small an intensity as pos 130 785,503 sible and it should be increased progressively, either continuously or in steps, so as to reach, after from five to ten minutes, the current necessary to commence electrolytic deposition on the workpiece being treated A shorter period sometimes is sufficient but it is convenient to stipulate a time of at least five minutes so that the process is suitable in the great mapority of cases If the current regulating means at the disposal of the bath operator does not allow a strictly continuous increase of the current intensity, the current regulation may be effected in from five to ten steps each of about one minute duration, the current being regulated during each of these periods at the corresponding fraction of the finally required current intensity For example, if the final current intensity is to be 80 amps, seven steps may be used each of one minute, the current during any step being 10 amps, higher than during the preceding step The starting current would be 10 amps after one minute it would be increased to 20 amps, after another minute it would be increased to 30 amps, and so on until a current of 80 amps had been reached The number of steps used can be varied according to the metal and shape of the workpieces being treated, but it appears that an increase of the current intensity in five steps, each equal to one sixth of the final electrolysis current required, is the most simple and conventional way to proceed in the mapority of cases In certain cases, according to the metal treated and the shape of the workpiece, a more rapid increase may give good results On the other hand, in certain other cases, a greater number of steps is recommended Again, after having reached a particular current step it is possible to decrease the intensity and

then to increase it again through its original value up to the next higher step. When the regulation described above has been completed it is only necessary to allow the electroplating process to proceed normally. The electroplating bath used must possess the quality of being able to produce an evolution of hydrogen to bring about the reduction of the oxide layer, and it must also be capable, when regulated to low current intensities, of functioning as a hydrogen generator without the deposition of metals, the latter only being produced with higher current intensities at the end of the above-described current regulation when the oxide layer has been eliminated Known electrolysis baths can therefore be classified under two headings, namely:(a) those which, in their usual method of functioning, satisfy the above requirements. By way of example mention may be made of the well-known chromium plating bath having the following composition:Grams per litre Chromic acid 250 Sulfuric acid 2 5 This bath may be used directly for the above described treatment of the workpieces The progressive regulation of the current intensity produces an evolution of hydrogen which eliminates the oxide layer before the com 70 mencement of the electrolytic deposition of chromium, which can thus be made directly on to the base metal. (b) those in which the usual method of functioning is not accompanied by an evolution of 75 hydrogen and in which the reduction of the oxide layer with hydrogen does not occur in the course of the above-described current regulation These baths, which usually have a high cathode yield, must have their composi 80 tions modified with the object of decreasing the cathode yield with, as a consequence, the replacement of the non-deposited metal with a corresponding evolution of hydrogen This modification should be effected in such a way 85 that no metallic deposition occurs at the commencement of the regulation, only hydrogen being produced, and that, at the end of the regulation, the entire workpiece is covered with a metallic electrolytic deposit After a 90 treatment of from 20 to 30 minutes in such a bath the workpiece preferably is transferred into a corresponding bath of the same unmodified composition, but with the usual current regulation, so that the electroplating process 95 proceeds at normal speed These modified baths are obtained in the majority of cases, from baths of normal composiiiion, serving for the continuance of the electrolysis, by decreasing the cathode yield, for example by 100 the addition of the acid corresponding to the princinal anion if it is a case of an acidic bath or by the addition of an alkaline cyanide if it is a case of an alkaline or cyanide bath. By way of example there may be mentioned 105 a nickel plating bath

constituted by a known nickel sulfate bath which has been modified by the addition of sulfuric acid This nickel plating bath may have the following composition: 110 Grams per litre Nickel sulfate (Ni SO 4,6 HO) 140 Sodium sulfate (Na SO,10 HO) 150 Sodium chloride (Na Cl) 24 Boric acid (HBOJ) 30 Free sulfuric acid (H 2504) 4 to 9 The operating temperature may be 32 C. and the final current density 10 amps per dmi. Other nickel plating baths may be employed by acidifying the bath by means of the acid corresponding to the anion of the base, for example a nickel chloride bath with hydrochloric acid. It is, of course, necessary to avoid treating a metal in a bath which will attack the metal or which will cause a chemical deposit on the metal treated. The above described process allows not only the cleaning of workpieces of aluminium, stainless steels (even with high chromium con785,503 tent) and other metals covered with an oxide layer, but also workpieces of certain other metals, such as iron and steels It is thus possible, in the case where a workpiece is made partly of a metal coated with oxide and partly of another metal, to submit the entire workpiece to treatment All parts of the workpiece will thus be coated with an electrolytic metal deposit in the course of the same operation. The process according to the present invention allows the electro-plating of workpieces which are normally covered with an oxide layer (in particular workpieces of aluminium or aluminium alloys), in which the deposited metal has such an adherence that the workpieces can be submitted to considerable mechanical efforts It is thus possible to obtain workpieces in which the properties of the basemetal treated are combined with the properties of the deposited metal, for example the hardness of chromium, resistance to oxidisation, resistance to corrosion, and so forth For example, by the process according to the invention it is possible to obtain chromium plated aluminium or aluminium alloy workpieces having a high thermal conductivity but which have a hard surface which is capable of receiving a mirror finish, which is resistant to chemicals or which has excellent frictional proD perties for mechanical uses By the process it is possible to obtain homogeneous mechanical assemblies, composed of a plurality of parts rubbing against one another, from the same metal, one or more of these parts being chromium plated (for example, light metal pistons for internal combustion engines operating in chromium plated liners of the same metal) It is also possible to obtain light rotating members having a low inertia but with a surface having a high wear resistance; such members are particularly useful in textile machines Again, it allows the manufacture of intermediate or

finished products of stainless steels associated with other metals by welding, rolling, drawing or other mechanical or nonmechanical process after electrolytic treatment of the metal. It is not possible to enumerate the many new applications of metals which are normally covered with an oxide layer (in particular aluminium alloys) and which, by the treatment according to the present invention, can be provided with a coating of electrolytically deposited metal, in particular hard chromium, thick nickel plating and coppering.

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* GB785504 (A)

Description: GB785504 (A) ? 1957-10-30

Rope tightening and snubbing device


PATENT SPECIFICATION Date of Appli h October 24, 11, No 30321/55. Application n November 1, l Complete Spec 785,504 cation and filing Complete Specification: 955. node in United States of America on 1954. ification Published: October 30, 1957. Index at acceptance:-Class 109, F. International Classification:-DO 7. COMPLETE SPECIFICATION Rope Tightening and Snubbing Device We, EASTERN ROTORCRAFT CORPORATION, a corporation organized under the laws of the State of Pennsylvania, United States of America, of Swamp Road at Doylestown,

Bucks County, Pennsylvania, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to rope tightening and snubbing devices. Rope tightening and snubbing devices for use with guy ropes and the like permit the effective shortening of a rope to take out the slack and secure it in the tightened position Known devices, while they provide for the tightening action and the prevention of slippage, are somewhat difficult to adjust because of the frictional action of the rope in passing through the device which usually produces sharp bends in the rope to provide for the snubbing action The construction which provides the sharp bends and deformations in the rope further caused damage to the rope when high loads were applied to it As a result, the rope fails in such devices at capacities considerable lower than the ultimate strength of the rope Many of these devices cause breakage of the rope at values of fifty per cent or less of the ultimate strength. According to the present invention we provide a tightening and snubbing device comprising a beam member having a large diameter fixed drum substantially at its mid region to receive the main rope load, a smaller fixed drum at one end of the beam to receive the reduced load in one side of a loop portion of the rope, and a rope attachment terminal at the other end of said beam. Further features of the present invention will be clear from the following description avn reference to the accompanying drawing, in which: Figure 1 is a view showing the device of the present invention as applied to a guy rope; Figure 2 is a plan view to an enlarged 50 scale of the device in adjusted position having a side plate cut away to show the interior; Figure 3 is view similar to Figure 2 but showing the device in the final position for 55 holding after adjustment has been accomplished; and Figure 4 is a sectional view taken along the line 4-4, Figure 2. In the arrangement illustrated in Figure 60 1 the guy rope 6 is anchored to a stake 7 by means of a looped portion of the rope having lengths 6 a and 6 b The snubber unit 8 provides the means for forming the looped portion 6 a and 6 b and for adjusting 65 the overall length of this portion Referring to the enlarged views, Figures 2, 3 and 4, it will be seen that the tightening device 8 incorporates a beam which is formed from two generally similar side plates identified 70 by the numeral 9 Near the deep centre portion of the beam, longitudinally considered, there is formed a drum 10 of relatively large diameter and toward one end of the beam a smaller drum 11 is formed, the two 75 drums occupying approximately one half the length of the beam It will be observed that the beam is formed with one edge straight and the

other edge tapered from the ends toward the deep center portion This 80 construction allows the placing of the large drum in an offset relationship to give increased length of rope engagement These drums guide the rope 6 through the device so that the main load carrying portion 6 85 enters the centre of the beam and emerges from the opposite side of the beam near one end of the unit as indicated by rope portion 6 a After passing around stake 7 the other loop portion of the rope 6 b is 90 785,504 securely tied to the opposite end of the plates 9 which form the beam From Figure 4 is will be seen that plates 9 at this end are brought together and a metal grommet 12 is used to hold them riveted firmly in position The hole through the grommet 12 serves as a means by which the end of the rope portion 6 b is fastened to the unit 8 A bent piece or clip 13 is formed on one of the side plates 9 to provide for holding the snubber unit in its final position after adjustment. Referring to Figure 4, it will be seen that the drum 10 is formed by means of an inwardly dished portion 14 at the deep section in each of the side plates 9 Similarly smaller drum 11 is formed by smaller diameter dished portions 15 By bringing the bottoms of the dished portions of each of the side plates together and fastening them by means of a large rivet 16 and a small rivet 17, the plates are held in rigidly assembled relationship and provide integrally formed smooth surface drums which permit the passing of the rope 6 through the device These dished portions have a height equal to at least one half the diameter of the rope to be used A washer 18 is provided under the large diameter rivet 16 in order to more fully distribute the load and maintain the parts in intimate assembled relationship. To adjust the device the unit 8 is pulled away from the stake 7 along rope 6 to remove all slack and is then pulled hand tight. This is done with the parts in the relative positions illustrated in Figure 2 In the "sopen" position the parts once adjusted will transmit without slippage the full load applied to the rope 6 However, the unit 8 is liable to be bumped by a moving object with the possibility of accidental movement in a loosening direction In order to place unit 8 in a secure and more compact position, it is swung around the position shown in Figure 3, where it is substantially parallel to the direction of rope pull 19 in which position the portion of the rope 6 a is retained in clip 13 In this position a greater length of travel around the drums is provided for the rope and at the same time portion 6 a of the rope presses against portion 6 which passes around large drum 10, thus providing additional holding capacity against slippage The proportioning of the unit provides that the full load rope portion 6 is positioned approximately midway between the looped portions of the rope 6 a and 6 b Thus when unit 8 is swung around to the position in

Figure 3 no appreciable shortening or lengthening action takes place since the relative position of the drums 10 and 11 is selected to avoid such lengthening or shortening Thus the tightness adjustment is not altered by swinging into the clipped position. From the foregoing it will be seen that we have provided an improved rope snubbing device The use of drums placed in the proper relative positions on the beam 70 unit provides adequate holding capacity to prevent slippage of the rope after adjustment but gives a smooth drum surface which allows smooth and easy adjustment to the tightened position The use of the dished 75 construction for the side plates allows the formation of the drums as an integral part of the plate units The clip formed on the end of the beam to which the rope is tied provides a simple method for holding the 80 snubber in adjusted position with the least amount of projection so that it is out of the way once adjustment has been completed. The use of a relatively large drum in contact with the most highly loaded end of rope 85 permits the transmission of substantially the full ultimate load through the rope without damage With this snubbing device, it is thus possible to use either smaller rope to do the work previously requiring a larger 90 rope or to use the same rope to carry a greater load.


* GB785505 (A)

Description: GB785505 (A) ? 1957-10-30

Improvements relating to irradiated polyethylene and products therefrom

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COMPLETE SPECIFICATION Iprovemen reating t4) Idiatetl Polyethylene and Produtcts Tlherefronn We, GENERAL ELECTRIC COMPANY, a Corporation of the State of New York, United States of America, having its office at Schenectady 5, State of New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to "irradiated polyethylene" by which term as used throughout this specification and in the claims is meant solid polyethylene which has been treated with high energy electrons to effect cross linking of the polyethylene and to yield a product which has improved resisttance to solvents and improved resistance to heat at elevated temperatures that is of about 125 to 175"C. or even higher. However, many applications using the irradiated polyethylene involve maintaining the irradiated polyethylene continuously for very long periods of time at such temperatures. In these cases it has been found that there tends to occur a degradation of the irradiated polyethylene as evidenced by the fact that the surface of the irradiated polyethylene becomes pitted and the irradiated polyethylene exhibits excessive flow. An additional difficulty encountered with irradiated polyethylene occurs when the latter is used to insulate electrical conductors, particularly copper conductors, either by wrapping irradiated polyethylene tape around the conductor or else extruding unirradiated polyethylene over the conductor and thereafter irradiating the insulated conductor. It has been found that when irradiated polyethylene is permitted to remain in contact with copper at elevated temperatures of about 125 to 175"C. or higher for lengths of time of about 25 to 50 hours or more, a reaction appears to occur with the copper causin~greening" which takes the form of a green film on the surface of the copper. The appearance of this green film reduces the adhesion of the polyethylene to the copper core and undesirably affects the electrical properties of the conductor while at the same time causing degradation of the irradiated polyethylene, the

degradation increasing with increase of temperature. If one incorporates the polyethylene oxidation inhibitors or stabilizers usually employed in the art, some improvement in the resistance to oxidation results but undesirable weight losses still occur at elevated temperatures. Although this rate of oxidation or degradation can be slowed down by incorporating larger amounts of the stabilizer, nevertheless such large amounts of stabilizer have undesirable effects on the electrical properties of the insulating conductor. In accordance with the present invention these drawbacks are overcome by applying to the surface of irradiated polyethylene a resinous coating which is capable of protecting the former from the effects of the oxygen on the polyethylene surface, while at the same time maintaining good adhesion between the resinous coating and the e irradiated polyethylene surface. The selection of the varnish used in the practice of the present invention is believed to depend on certain requirements. The varnish should be tough and flexible, and resistant to cracking in the cured or hardened state when applied to the irradiated polyethylene surface, and should have good adhesion to the irradiated polyethylene surface. It was surprising and in no way could have been expected that the use of the varnish treatment on the irradiated polyethylene would produce the results described herein because using many of the same varnishes herein employed on unirradiated polyethylene, difficulty was encountered in obtaining continuous, uniform films which would adequately wet the surface of the polyethylene. Unexpectedly, it was found that after irradiation of the polyethylene with high energy electrons, all difficulties in this respect disappeared and these very same varnishes, when used to coat the irradiated polyethylene, formed uniform, continuous films on the surface of the latter and appeared to wet the irradiated polyethylene surface at every point with which the varnish came in contact. Varnishes found to be especially suitable in the practice of the present invention comprise phenolic varnishes made from a phenol and an aldehyde, furthermore, modified phenolic varnishes, for instance, those modified with oils, with alkylated phenols, with rosin or its derivatives, as well as oilmodified reaction products of polyhydric alcohol-polybasic acid reaction products (commonly identified as "oil-modified alkyd resins"), rosin-modified alkyd resins, phenolic-modified alkyd resins. The varnishes used may be in a sufficiently low molecular weight form that they do not require solvent to maintain a liquid condition, or they may be varnishes dissolved in suitable solvents, for instance, petroleum spirits, xylene, liquid aliphatic hydrocarbons, butanol, aliphatic acylates,

for instance, amyl acetate. Among the varnishes which may be employed for the above-identified purposes are, for example, phenol-aldehyde varnishes (for example, condensation products of phenol and formaldehyde, phenol and acetaldehyde), modified phenolaldehyde reaction products, as, for instance, those modified with alkylated phenols, for example, those modified with cresols, tertiary butyl phenol-modified phenolaldehyde resinous materials; phenol-aldehyde modified polyvinylal resins; ethoxylene resins; oil-modified phenol-aldehyde resins, for instance, oilmodified para-tertiary amyl phenol-aldehyde resins, rosin-modified phenolic condensation products; modified alkyd resins in which the alkyd resins are resinous condensation products resulting from the reaction of one or more polyhydric alcohols with a polycarboxylic acid (or anhydride), with one or more of the following modifying ingredients, for instance, rosin; modifying oils, e.g., nondrying oils, semi-drying oils, drying oils, fatty oils, fatty oil acids, derived either from vegetable or animal sources or produced synthetically; esters, specifically glycerides of fatty acids; and mixtures of one or more of these modifying ingredients with natural resins. Examples of polycarboxylic acids (or anhydrides) used in the manufacture of the aforesaid alkyd resins are oxalic, malonic, succinic, adipic, azelaic, phthalic, halogenated phthalic acids, for example, tetrachlorophthalic acid or anhydride, 4-chlorophthalic acid, isophthalic acid, terephthalic acid, adducts of hexachlorocyclopentadiene and maleic anhydride. Examples of polyhydric alcohols (dihydric, trihydric, etc.) which may be used in formulating the varnishes employed in the practice of this invention are ethylene glycol, diethylene glycol, propylene glycol, glycerine, sorbitol, pentaerythritol. Monohydric alcohols, for example, those boiling above 150 C., such as alkyl ethers of glycols, for instance, alkyl ethers of ethylene and diethylene glycol, may also be used for modification purposes. The modifying ingredients may comprise modifying oils in the raw, heated or blown state which may be employed in making the modified alkyd resins, for example, linseed oil, chinawood oil, castor oil, soya bean oil, oiticica oil, linseed oil acids, coconut oil acids, palmitic acid, stearic acid, oleic acid. The amount of the modifying ingredients may be varied within wide limits, for example, from 5 to 70 per cent, preferably from 10 to 60 per cent, by weight, of the total weight of the modifying ingredient, the polyhydric alcohol and the polybasic acid or acids (or anhydride if used) present in the reaction mixture.

The above-described varnishes, particularly the phenolic varnishes and the oilmodified alkyd varnishes, may be further modified with amine-aldehyde resins, for instance, melamine - formaldehyde resins, urea-aldehyde resins, and modified aminealdehyde resins, as, for instance, the abovementioned melamine-formaldehyde resins modified with butyl alcohol, ethyl alcohol. The varnish applied to the irradiated polyethylene surface is preferably in a dilute concentration and advantageously has a solids content of about 10 to 60 per cent for ease of application. The manner of application of the varnish to the irradiated polyethylene surface may be varied widely. Thus, one may employ dipping techniques, that is, dipping the irradiated polyethylene article or surface in the liquid varnish or varnish solution, by spraying, by brushing the varnish on the irradiated polyethylene artic'e, or surface. The thickness of the resinous coating should range from about 0.0005 of an inch up to a thickness where flexibility of the film is impaired after continued exposure to elevated temperatures. Such upper thicknesses are advantageously about 0.01 of an inch, although thicker coatings may be employed in certain applications using irradiated polyethylene. After application of the varnish to the irradiated polyethylene surface, the treated polyethylene may then be advantageously heated at temperatures of about 100" to 125"C. for times varying from about 15 minutes to an hour to effect cure and drying of the varnished surface. acceleration of this curing may be effected by raising the temperature to-about-I-5C to 175or. Additional acceleration in the drying of the outer varnish coating may be obtained by incorporating cure accelerators in the varnish prior to application to the irradiated polyethylene surface. Among such cure accelerators may be mentioned various dryers including metallic salts of long-chain fatty acids, for instance, iron octoate, tin oleate, manganese octoate, as well as various other metallic salts, such as lead naphth en ate, iron naphthenate, manganese naphthenate. The amount required for these cure accelerators to exert the desired action is relatively small and usually is below 0.5 per cent based on the weight of the resinous coating material. The polyethylene referred to herein is a solid polymeric material formed by the polymerization of ethylene at high temperatures and pressures. It may range in molecular weight from about 10,000 to as high as 30,000 or more. The accelerator apparatus used to irradiate the polyethylene with high energy electrons so as to cross-link it is a high voltage accelerating apparatus capable of producing a beam of high energy electrons. A suitable high voltage accelerating apparatus is described in Electronics, Volume 16, pages 128-133 (1944).

The irradiated polyethylene employed herein may have been subjected to various irradiation doses, for instance, of the order of from about 2 x 106R to as high as 15 to 20 or more x 106R. In general, the irradiation dose will depend upon such factors as the application involved, the type of polyethylene used (its molecular weight, method of preparation, etc.), whether it is to be subsequently milled and moulded. If the polyethylene is irradiated beforehand in the form of for example sheets or tapes and thereafter applied, for instance, as insulation for conductors, it is possible to use higher irradiation doses than if it is to be irradiated, milled and then extruded, for instance, over electrical conductor. In addition, polyethylene-fabricated articles, for instance, containers or gaskets, may be irradiated at higher irradiation doses since the irradiated article will not be subjected to any further physical deformation either before or after treatment with the varnish coating. Accordingly, it is readily apparent that the irradiation dose that the polyethylene will be subjected to is not critical in the practice of this invention. The incorporation of fillers, either before irradiation or after iradiation, and before milling or during milling is not precluded. Among such fillers may be mentioned carbon black and various finely divided silica fillers, such as silica aerogel and fumed silicas, the latter being prepared by deposition of silica in a finely divided state from silica fumes. The polyethylene which is subjected to irradiation may be in any physical state or size. Thus, if it is in a finely divided state and is later to be subjected to a milling action and moulded, for instance, extruded, it may be in the form of finely divided particles which can readily assimilate the high energy electrons. On the other hand, th polyethylene during the irradiation operation may be in the form of a formed article such as a bottle or a gasket, or it may be in the form of polyethylene insulated conductors which are then subjected to irradiation with high energy electrons, electrical equipment containing irradiated polyethylene in its insulation system, e.g., slot liners in motors, taped coils in motors and generators, layer insulation in coils and transformers or protective tapings. In connection with insulated conductors containing irradiated polyethylene as insulation, it is to be understood that these insulated conductors may be used in various applications including the manufacture of windings for motors, generators and transformers, which can be thereafter coated either as individual conductor strands or as a total equipment with the above-described varnishes. In the following examples, all parts are by weight: Example I A sheet of polyethylene about 0.1" thick was irradiated with high

energy electrons to a dose level of 15 x 10tor (RRoentgen units). A square of this irradiated sample was coated by dipping it in a varnish solution comprising a rosin and linseed oilmodified glyceryl-phthalate varnish which was further modified with a resinous composition composed of a reaction product of formaldehyde and p-tertiary butyl phenol. Treatment of the irradiated polyethylene sample was carried out by dipping the entire sample in the varnish (which was at about a 50% solids concentration and contained about 0.1 per cent of a drier, speciffcally lead and cobalt naphthenates) and thereafter baking the sample at about 125"C. for about 1-3/4 hours to cure the varnish. Thereafter, this sample, together with an uncoated sample of similar thickness of the above irradiated polyethylene, was placed in a 150 C. air circulating oven and the weight of the sample noted at various intervals after having first recorded the weight of the sample prior to insertion in the oven. At the end of 50 hours at 150"C., the weight of the uncoated irradiated polyethylene sample began to drop sharply and the sample showed visual signs of degradation as evidenced by surface pitting and melting at the edges. When removed from the oven after 50 hours at 150 C., the sample was losing weight at the rate of 25 per cent of its original weight per 1000 hours at the 150 C. temperature. In contrast to this, the sample coated with the above-mentioned oil-modified, rosin-modified, phenolic-modified glyceryl phthalate resin after 55G0 hours showed no evidence of surface pitting, or melting at the edges, or sagging, and was losing weight at the rate of only 0.5 per cent of the original weight per 1000 hours. Example 2 In this example, copper wire, about 1/4" in diameter was wound with a polyethylene tape 0.005" x 1" (molecular weight about 21,000) which had been irradiated to a dose of 7.5 x 10go. One layer, half-lapped, of this irradiated tape was wound on the conductor. Another taped conductor was pre pared exactly as above, but in addition the taped conductor was dipped in a rosinmodified, linseed oil-modified, glre-r;'- phthalate varnish similar to that employed in Example 1, with the exception that it was not modified with the phenolic resin. This varnish also contained the driers described in Example 1. The coated, insulated conductor was kept at room temperature for about 12 hours to evaporate the solvent, and to effect room-temperature cure of the outer resinous coating. The treated, insulated conductor and the untreated insulated conductor were placed in a IOOGC. aircirculating oven and the condition of the insulation in direct contact with the copper core was noted in each instance. After 72 hours, the insulated conductor which had not been coated on the outside with the

glycerylphthalate resin solution showed "green" spots in the insulation, and the insulation had become weak and cheesy. In addition, the copper surface showed signs of corrosion as evidenced by greenish spots and roughening. In contrast to this, the taped conductor which had been coated with the varnish showed no apparent sign of copper corrosion or discolouration of the polyethylene insulation even after 500 hours at 100 C.; the strength of the insulating tape had not deteriorated to any noticeable extent. Another taped conductor prepared similarly to the above and coated with the same varnish described in the present example was placed in a 150"C. aircirculating oven. At the end of 500 hours, the polyethylene insulation was colourless and its strength appeared to be unchanged despite the drastic conditions to which the insulated conductor had been subjected. Example 3 Polyethylene tape, 1" wide and 0.005 thick was treated with high energy electrons to a dose of 7.5 x 106R. This tape was wound around a 1/4" diameter copper wire to give a total polyethylene thickness of 0.060". Another similarly insulated copper wire was dipped in the glycerylphthalate varnish in Example 2 above, and maintained at room temperature for about 12 hours to effect drying and curing of the outer varnish coating. Thereafter, the coated and uncoated insulated conductors were placed in a 200or. air circulating oven and the effect of this high temperature and air noted at various intervals. The insulated conductor which had not been coated with the varnish darkened badly in less than 48 hours and became almost black. In addition, it showed extreme surface pitting and the insulation had become very weak and "cheesy," and the polyethylene could no longer be cold-drawn. In contrast to this, the sample which was coated with The glyceryl-phthalate varnish, although it had deteriorated somewhat after 500 hours at 200 C., nevertheless, the polyethylene underneath the varnish was still colourless and retained its physical properties as evidenced by the fact that it was tough, flexible and could be readily cold-drawn. By incorporating certain specific types of stabilizers in the polyethylene prior to the latter's irradiation with high energy electrons and by the coating of the irradiated polyethylene with a suitable varnish, still further improvements in resistance to deterioration in air at elevated temperatures are obtained. The following example illustraces this. E,rasnple 4 Polyethylene containing two amounWs asp stabilizer (the stabilizer being N,N'dinaphthyl-p-phenylene diamine) was sheeted and samples of each were subjected to irradiation with high energy electrons to a dose of 15 x 10'R. Thereafter, a sample Oe each

stabilized, irradiated polyethylene sheet was dipped, in one instance in the phenolic modified, rosin-modified, drying oil-modified alkyd varnish containing the two aforesaid driers (identified as "Varnish A") described in Example 1, while the other stabilized and irradiated polyethylene sample was dipped in the rosin and drying oil-modified alkyd varnish (identified as "Varnish B") described in Example 2. Each coated sample was dried at room temperature for about 4 hours. Sample sheets, both coated and uncoated with the varnishes, were placed in an aircirculating oven and maintained at a temperature of 150 C. for varying lengths of time, and periodically examined to determine the effect of the heat-aging. The following Table I shows the results of these heat-aging tests in which table is described the rate of weight loss at failure, and the time at which failure occurred, namely, when the polyethylene became dark, pitted, and began to curl at the edges. TABLE I Weight Time to Per Cent Failure at Rate of Weight Stabilizer Varnish 150"C. loss 0.2% None 1000 hours 12%/1000 hrs. 0.50/O None 2000 hours 3%!1000 hrs. 0.2% Varnish A OK after 0.6%/1000 hrs. 5500 hrs. (at 5500 hrs.) 0.5% Varnish B OK after 0.15%/1000 hrs. 2800 hrs. (at 2800 hrs.) It will be clearly apparent from the above Table I that the stabilizer alone incorporated in the irradiated polyethylene failed to give satisfactory stabilization against continued heating at 150or. In contrast to this, the irradiated polyethylene samples containing the stabilizer and further coated with a varnish, markedly improved the stability of the irradiated polyethylene so that in one instance after 5500 hours no apparent deterioration had occurred while in another instance after 2800 hours, the sample was apparently unchanged. Note should also be taken of the improvement of the combination of stabilizer (containing 0.5 per cent stabilizer) and the overcoating of the varnish whereby the rate of weight loss was only 0.15 per cent per 1000 hours, as compared to the weight loss of 0.5 per cent 1000 hours in Example 2 without the stabilizer. One of the unexpected advantages residing in the use of a cured varnish overcoat superposed upon the irradiated polyethylene is the marked increase in abrasion resistance of such coated irradiated polyethylene surfaces. The following example illustrates this embodiment of the invention.

Example 5 Two layers of 0.005" thick polyethylene tape taped around a 3/8" square brass bar were heat-sealed and thereafter irradiated with high energy electrons to a dose level of about 7.5 x 106R. Samples of the irradiated polyethylene were dipped twice in a varnish comprising a soya oil-modified alkylated phenol-formaldehyde resin dissolved in a solvent comprising xylene and petroleum spirits to about a 50 per cent solids concentration and thereafter dried each time at room temperature for about 4 hours to volatilize the solvent and to cure the resin. An additional sample was prepared by dipping two layers of 0.005" thick glass tape twice in the same modified glyceryl-phthalate resin and dried similarly as above. Samples of the coated and irradiated polyethylene and of the coated glass tape, as well as samples of the irradiated polyethylene which had not been dipped in any varnish, were heat-treated for varying lengths of time. At the end of these heat treatments, the abrasion resistance of each surface was tested employing a 4-pound weight in the Carboloy washer test, more particularly described in an article entitled "Fabric Abrasion Testing" by K. N. Mathes, published in General Electric Review dated November 1940, Volume 43, pages 467-470. The following Table II shows the results of these tests. TABLE 11 Heating Schedule irradiated Polyethylene Samples Glass Tape Dipped No Varnish Treated with Two in Varnish Treatment Coats of Varnish Heated 3 hrs. 1560 turns 20,000 turns 1500 turns at 150 C. Heated 35 days Flowed and 3,400 turns 780 turns at 150"C. couldnotbe tested Similar results were obtained as above employing a water-soluble phenol-formaldehyde resin which by itself was quite brittle in the cured state. However, when this resin in the form of an alcohol-water solution was applied to the irradiated polyethylene surface and then heated for 35 days at 150,C., it was found that the coated polyethylene was extremely flexible and had good abrasion resistance. In making motors, instead of using insulated conductors insulated with irradiated polyethylene and thereafter coated with the protective varnishes, the insulated conductor may be formed into the core or winding of the motor, and the entire assembly dipped in the varnish, and thereafter baked to effect curing of the resinous coating on the ir radiated polyethylene insulation. As a further means of practicing the present invention, sheets composed of irradiated polyethylene may

be coated on one side with the varnish and thereafter slit into the form of tapes, which can then be used for insulating or protective purposes. The invention is also eminently suitable in the packaging of various objects employing for the container irradiated polyethylene. By treating the irradiated polyethylene film with the resinous material to form the coating, either before or after it is placed around the object which it is desired to confine, the irradiated polyethylene can be subjected to elevated temperatures without deterioration of the latter due to the effects of the oxygen in the air. By evacuation of the area confined by the polyethylene, one can obtain sealed objects which can be maintained at elevated temperatures, for instance, for sterilization purposes, without deterioration of the polyethylene film, either on the exterior coated side or the interior uncoated side. What we claim is: 1. Irradiated polyethylene coated with a uniform continuous protective resinous coating which is firmly adherent to the irradiated polyethylene surface. 2. Irradiated polyethylene as claimed in claim 1, in which the resinous coating comprises a resinous polyhydric alcoholpolycarboxylic acid reaction product. 3. Irradiated polyethylene as claimed in daim 2, in which the reaction product is an oil-and phenolic-resin-modified glycol phthalate resin. 4. Irradiated polyethylene as claimed in claim 2, in which the reaction product is a resin-modified glyceryi-phtlialate resin. 5. Irradiated polyethylene as claimed in claim 1, in which the coating comprises a phenol-formaldehyde resin 6. An insulated conductor composed of a metallic core, insulation comprising irradiated polyethylene, and an outer uniform and continuous resinous coating superposed upon the irradiated polyethylene and having firm adhesion to the surface of the irradiated polyethylene. 7. An insulated conductor according to claim 6, wherein the outer resinous coating comprises a resinous product of a polyhydric alcohol and a polycarboxylic acid. 8. An insulated conductor according to claim 6, wherein the outer resinous coating comprises a glyceryl-phthalate resin modified with a phenol-aldehyde condensation product. 9. An electrical winding comprising a wound conductor composed of a metallic core, insulation for the latter comprising irradiated polyethylene, and an outer coating on the irradiated polyethylene comprising a uniform continuous protective resinous coating firmly adherent to the irradiated polyethylene surface. 10. A method of preventing undesirable deterioration of irradiated

polyethylene at elevated temperatures which comprises coating the aforesaid irradiated polyethylene with a resinous composition which is uniformly and continuously coated on and firmly adherent to the irradiated polyethylene surface. 11. A method according to claim 10 wherein the resinous composition comprises a reaction product of a polyhydric alcohol and a polycarboxylic acid. 12. A method according to claim 11 wherein the resinous composition comprises a glyceryl-phthalate resin modified with a phenol-aldehyde condensation product. 13. A method according to claim 10 wherein the resinous composition comprises a phenol formaldehyde condensatio


* GB785506 (A)

Description: GB785506 (A) ? 1957-10-30

Electric welding medium

Description of GB785506 (A) Translate this text into Tooltip



PATENT SPECIEICATION 785,5906

Date of Application and filing Complete Specification: October 31, 1955. No 31100/55. Application made in United States of America on December 17, 1954. Complete Specification Publishcd: October 30, 1957. Index at aceptance:-Ciarges 82 ( 2), M; and 83 ( 4), T 6. Internantinmal Ciaslificatien:-B 23 k. COMPLETE SPECIFICATION Electric Welding Medliria We, UNION CARBIDE CORPORATION, (formerly known as UNION CARBIDE AND CARBON CORPORATION), a Corporation organised under the laws of the State of New York, United States of America, of 30 East 42nd Street, New York, State of New York, United States of America, do hereby declare the invention, for which vie pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention rel ltes to that type of electric welding process in which metal is deposited from a bare welding electrode while the welding zone is covered with a deep layer of a granulated welding composition, and in particular is concerned with a welding medium which makes possible the welding of light gauge sheet metal at high speed. The welding process referred to was originally developed for the welding of heavy sections and has found its greatest utility in the production of welds in plate ranging in thickness from about 1/4 inch to 4 inches ( 6.4 mm to 10 2 cm) The sound, strong welds made automatically and quickly by this welding process have made it attractive for ever-widening fields of application Much time and effort have been expended in an endeavour to adapt the process for use in automatic high speed welding of thin sheet metal While good welds have been made with conventional welding compositions in such thin sheet at rates up to about 150 inches ( 381 cm) per minute, the demand for higher and higher production rates has led to a continuing demand for a medium which would permit welding such material at higher speeds than have been heretofore possible. It is the principal object of this invention to provide a welding composition which makes possible the attainment of high weld(P-d ing speeds in light gauge sheet metal. It has now been found that this object may be attained with a granulated electric welding mediurn containing as essential constituents manganese oxide, titania, and silica 50 and which may also contain, and preferably does, small quantities of alumina and vanadium pentoxide Oxides of iron (Fe O), calcium (Ca O) and magnesium (Mg O) are also generally present 55 Specifically, the granulated welding composition according to the invention contains by weight 15 o

to 28 %' silica, 17 ' to 35 % titania, 40 % to 50 % manganese oxide (calculated as Mn O), up to 7 5 % alumina, up 60 to 5 % calcium fluoride, up to 1 % vanadium pentoxide, and up to 7 5 % in the aggregate of one or more of the compounds iron oxide (calculated as Fe O), lime and magnesia. Preferably, the iron oxide and lime do not 65 each exceed 3 % in the presence of each other, and the magnesia generally does not exceed 2 % '. A preferred range of composition by weight is: 17 % to 20 % silica, 20 % to 24 % 70 titania, 44 % to 48 % manganese oxide, (calculated as Mn O), 3 5 % to 5 5 % alumina, 2 %' to 3 % calcium fluoride, 0 3 % to 0 7 % vanadium pentoxide, up to 3 % iron oxide (calculated as Fe O), up to 1 % lime, and up 75 to 1 % magnesia Moreover, it is particularly pointed out that the composition is not predominantly a silicate as are conventional media and that the silica content must be within the ranges defined herein to 80 achieve the desired results. The welding medium of the invention is preferably pre-fused and is prepared in conventional manner as by fusing raw materials such as silica, rutile and manganese ores 85 The molten mixture is then cast onto chills for solidification The solidified mass is crushed to size, for instance to " 12 x 200 ", that is, so that all will pass a 12-mesh screen ( 1.397 mm openings) and will be retained 90 Ricc, A?' 785506 on a 200-mesh screen ( 074 mm openings), and is then ready for use. In the following table analytically determined proportions of the essential components of a number of particular compositions embodying the invention are set forth All of the tabulated compositions have been found to be uniformly satisfactory for welding light gauge sheet metal at speeds as high as 200 inches ( 508 cm) per minute The 10 figures in the table for each composition do not necessarily add up to 100 %-', since no account has been taken of experimental variations and unanalysed remainders. % COMPOSITION Ti Q Mn O Fe O Ca O 29.00 43 17 3 15 2 71 21.42 44 20 2 25 2 98 20.13 40 84 1 98 1 85 21.42 45 64 4 38 22.16 46 09 1 94 8 17,74 42 42 3 45 2 49 20.53 46 04 1 93 1 49 not determined. BY WEIGHT Mg O A 1 03 0.37 4 24 0.16 2 42 2.05 6 06 40 8 4 94 1.20 5 40 1.04 4 58 Ca F 2 V 205 2.52 1.98 2.62 2.30 0.63 0.63 0.56 0.71 As indicated above, the welding medium of the invention has proved to be satisfactory in all respects when used in producing welds in light gauge sheet metal at high speeds For example, each of the tabulated compositions was used in making welds at speeds of 100, 150, and 200 inches ( 254, 381 and 508 cm) per minute in a series of tests In each case, square edged butt welds were made in 0 078 inch ( 1 98 mm) thick low carbon steel sheet At a welding speed of 100 inches ( 254 cm) per minute, the welding current used was 325 amperes, the voltage 21 volts

At 150 inches ( 381 cm) per minute, welding current was 400 amperes, voltage 22, and at 200 inches ( 508 cm) per minute, the welding current was 490 amperes, the voltage 22 volts In each case, direct current was employed with reverse polarity In each case, and at every speed, sound welds were produced with complete penetration The welds were substantially free of undercutting, pock marks, blowholes, cracks or other imperfections normally encountered with the use of former welding compositions at such high welding speeds. The weld deposit was about 1/8 in ( 3 18 mm.) wide in each case using a 3/32 inch ( 2.38 mm) diameter steel welding electrode containing 1 % manganese, 0 15 % carbon, and 0 2 % silicon. The welding composition of the invention has also been proved useful in welding plate up to one inch ( 2 54 cm) thick in a single pass, single-pass welds in one inch ( 2 54 cm) plate being produced at a speed of about 11 inches ( 27 9 cm) per minute under appropriate welding conditions. Among the advantages of the composition of the invention, is the fact that it may be used on dirty, oily or rusty sheet metal 65 without producing inferior welds.


* GB785507 (A)

Description: GB785507 (A) ? 1957-10-30

Radiochemical preparation of copolymers of maleic anhydride and olefinicmaterials


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US2955994 (A) US2955994 (A) less Translate this text into Tooltip



PATENT SPECIFICATION 7859597 Date of Application and filing Complete /Aj\ I Specification: November 11, 1955 No 32271/55 Application made in United States of America on December 16, 1954 \-'/ D Complete Specification Published: October 30, 1957 Index N ueceptauce:-Cla'ses 1 ( 1), C; and 2 ( 6), P 7 A, P 7 (N:i 1 X:2 A 1:2 B:38), lP 7 K( 7:9), P 72 ( 35 i 6 Xt), P 7 T 2 (D G), P 9 A, P 9 I(INA 1:8), P 9 K 7, P 9 P( 3:5:6 X), P 9 T 2 (D G). uternatfional Ciasfication:-B 13 C 60 If. COMPLETE SPECIFICATION Radiochemical Preparation of C opolymers of Malelc Anhydwide and Olefinic Materials We, Esso RESEARCH AND ENGINEERING COMPANY, a Corporation duly organised and existing under the laws of the state of Delaware, United States of America, of Elizabeth, New Jersey, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to improvements in carrying out polymerization reactions More particularly, the invention is concerned with the initiation, activation or promotion of polymerization reactions by nuclear radiation In brief compass, the invention pertains to an improved method of carrying out polymerization reactions by exposing the reagents to radiation emitted by radioactive materials, particularly the radioactive fission products obtained as byproducts or waste materials in the operation of atomic piles for the production of atomic energy. More particularly, the invention pertains to the polymerization and copolymerization of unsaturated compounds by exposing mixtures of unsaturated monomers to the radiation emitted by sources of high energy radioactivity By a proper selection of the starting materials, radiation intensity and radiation time, polymers useful as ionexchange

resins, soil conditioners and the like are obtained. Polymeric materials have been prepared heretofore by polymerizing mixtures of the monomers involved at elevated temperatures of about 100 '-400 'F in the presence of various catalysts, particularly peroxides, such as benzoyl peroxide and others This method involves a rather complicated process control since, in many cases, relatively lPrice 3 s 6 d l high initial temperatures are required to start the reaction while thereafter the temperature must be carefully controlled and 45 sometimes reduced to prevent over-polymerization or gelation Also, the product must be treated to remove or neutralize the catalyst or its degradation products as well as certain other by-products which usually 5 G interfere with the contemplated use of the polymer Last but not least, it is difficult to operate this process in a continuous fashion because of the required control of a plurality of process variables, such as time, tempera 55 ture, catalyst concentration, etc The present invention overcomes these difficulties and affords various additional advantages as will appear from the description hereinafter. The present invention comprises a process 60 i of copolymerisation which comprises exposing a mixture of maleic anhydride and an olefinic material to a radiation of at least 10,000 R/hr for a time sufficient to effect polymerisation: the olefinic material being a 65 non-conjugated diolefin, a mano-olefin or a mixture of a non-conjugated diolefin and a mano-olefin. Types of radiation suitable for the purposes of the invention include high energy 70 electromagnetic radiation such as gamma rays and X-rays; and high velocity electrons such as beta rays; as well as alpha particles. These types of radiation may be supplied by naturally occurring radioactive materials, 75 such as radium and its compounds, which emit alpha, beta and gamma rays Fission by-products of processes generating atomic power and/or fissionable materials, which emit high energy gamma rays, afford a 8 so highly desirable and most abundant source of radioactivity suitable for the purposes of the invention These by-products include elements with atomic numbers ranging from 785,507 (zinc) to 63 (europium) and their compounds They are formed in the course of converting uranium, thorium and other fissionable material in an atomic reactor. Radiation from an operating reactor itself can also be used Only sources of radiation from which a field intensity of at least 10,000 R/hour can be obtained are practical for the purposes of this invention. Materials made radioactive by exposure to neutron radiation, such as radioactive cobalt (Cow), europium 152 or europium 154 which emit gamma rays, may likewise be used Suitable sources of high velocity

electrons are the beams of electron accelerators, such as the Van de Graaf generator or the Betatron In general, however, high intensity gamma radiation and its well known sources, such as nuclear fission by-products, operating nuclear reactors, and materials made radioactive by neutron radiation are preferred for the purposes of the invention mainly because of the relatively high penetrating power of gamma radiation. The process of the invention has several important advantages Polymerization by means of radioactive irradiation is no more expensive than polymerization by means of conventional chemical procedures, such as peroxide catalysis In addition, this process possesses the following advantages: 1 High temperatures are not required to initiate the polymerization reaction This means that the polymerization may be carried out at ambient temperature without providing heat for the process With peroxide initiated polymerization of the prior art the reaction mixture must be heated to a temperature range in which the peroxide will decompose In using benzoyl peroxide, one of the more common methods for initiating commercial polymerization reactions, it is necessary to heat the reactants to the neighborhood of 120 '-200 'F for polymerization to occur. 2 The reaction is easily controlled With peroxide polymnerization catalysts, the rate at which the chain initiators are produced depends not only upon the concentration of the peroxide and the temperature, but also upon little understood secondary chemical changes in the peroxide decomposition products The rate at which chain initiating gamma rays are produced by the radioactive source is constant for long half-life isotopes. Therefore, at a given temperature the copolymerization will be quite even and not subject to sudden acceleration or deceleration as is the case with peroxide catalysts. Also, with conventional peroxide catalysis it is necessary to heat the reaction mixture to initiate the polymerization process after which rapid cooling may be required so that the polymerization does not run away Diffilcult control problems of this type are avoided in accordance with the invention. As a result, the products have a more uniform molecular weight range which will result in quality advantages Another effect 70 of this regular reaction rate is the production of a clear, water-white product which is superior in appearance to that produced by conventional chemical methods. 3 There is no catalyst contamination in 75 the products polymerized by gamma irradiation Since the radioactive material need not come in direct contact with the reactants, and since the gamma rays themselves

are merely light, the problem of removing 80 initiating materials from the resulting polymer does not exist The absence of catalyst contamination in the final product results in greater thermal stability of the polymer. It should be pointed out that gamma ray 85 irradiation does not make a substance radioactive. 4 Radiation initiation is readily adaptable for continuous polymerization processes Since the irradiation from isotope 90 sources is given out on a 24-hour per day basis from an irradiation source, and since its emission is regular and is not affected by temperature or other outside phenomena, the catalytic effect is controlled in such radiation 95 initiated polymerizations solely by the time of residence of the reactant within the irradiation zone For all practical purposes, the initiator is not consumed as is the case with chemical initiators In addition, a radia 100 tion source, such as a gamma ray source, produces no products which must be removed from the reaction zone These features permit the design of a plant which can manufacture polymer on a 24-hour per day 105 basis by merely pumping monomers through the radiation given out by a suitable source. The above-described process may be applied, according to the present invention, to the production of copolymers of maleic 110 anhydride with a mano-olefin, a nonconjugated diolefin or with a nonconjugated diolefin and a mono-olefin A solvent for the reaction will generally be necessary since maleic anhydride is relatively 115 insoluble in the hydrocarbon olefins Suitable solvents may be dioxane or ethyl acetate The temperature of the reaction mixture need not be elevated and may cover the range from O ' to 300 'F, preferably 120 ' to 80 'F The polymerization may be carried out for 0 5 to 24 hours at an intensity of radiation of 100,000 to 5,000,000 R/hr. When a non-conjugated diolefin is used alone with maleic anhydride a cross-linked, 125 insoluble resin is usually obtained with a composition of 1 mole of olefin to 2 moles maleic anhydride The ratio of maleic anhydride to diolefin then will probably range from 1/1 to 511 with a ratio of 2/1 130 V 85,507 preferred These products will usually be more useful as ion-exchange resins after hydrolysis of the anhydride portions of the molecule due to their insolubility. In order to obtain a partially soluble, slightly less cross-linked polymer for use as a soil conditioning agent, part or all of the diolefin is replaced with mono-olefin In this case the ratio of reactants has a much wider J O range covering maleic anhydride/combined olefin of 1/5 to 5/1 with the ratio of olefins covering the range diolefin/olefin of 95/5 to 5195 or even 0/100. Diolefins which may be used include :55 dimethallyl; pentadiene 1,4; or hexadiene 1,4 or 1,5; heptadiene 1,4; heptadiene 1,5; and

heptadiene 1,6 Alkyl or aryl substituted diolefins related to the above examples may also be used. Olefins which may be used include any paraffinic, naphthenic, or aromatic monoolefin such as butene-2, isobutylene, cyclohexene, vinyl cyclohexane and styrene. Conventional means of irradiating materials with ionizing radiation may be employed to carry out the process of the invention For example, batches of the reaction mixtures may be inserted in, or reactant streams passed through, pipes made of or containing the radioactive material and shielded from the outside to protect the operator Another suitable arrangement is described in British patent 708,901, published May 12, 1954 In accordance with this procedure, liquefiable organic substances such as petroleum fractions are fed to a pile containing fissionable material where they are held for a sufficient time to effect the desired radiation The irradiated material is -4, passed to shielded storage tanks where the product is allowed to gradually lose its activity It is then fractionated and otherwise treated Other suitable means for carrying out the process of the invention may appear to those skilled in the art For example, solutions of the monomers may be exposed to the high intensity radiation emitted by radioactive isotopes or high voltage accelerators. -50 The invention will be further illustrated by the following specific examples. EXAMPLE I. A solution of 13 2 gm ( 0 12 mole) of dimethallyl and 11 8 gm ( 0 12 mole) of maleic -55 anhydride in 25 gm of dioxane was irradiated for 24 hours at room temperature in a 250,000 R /hr Cobalt 60 source-total dosage 6 x 101 R A white insoluble polymer settled from the solution and was separated by filtration After drying it weighed 18 4 gm and did not melt below 290 'C The filtrate from this solid yielded no solid residue after evaporation Thus, the 18 4 gm of polymer is comprised of 11 8 gm maleic anhydride and 6 6 gm, dimethallyl or almost exactly 1 mole dimethallyl and 2 moles of maleic anhydride The calculated and found analyses for a cross-linked polymer of this composition are compared below: Calculated Found 70 % C 62 7 59 98 % H 5 9 7 10 % O 31 4 32 66 0 99 74 75 This solid was refiluxed with potassium hydroxide in order to hydrolyze the anhydride portion of the molecule and form the potassium salt 2 7 gm was refluxed for hours with 20 gm KOH in 50 cc water, 80 cc ethanol, and 25 cc isopropanol The solid was then recovered, washed with hot methanol and dried to yield 4 3 gm product. A sulfated ash determination on the product was 52 1 %, equivalent to 23 4 % K in the 85 solid (calculated for the K salt of a completely hydrolyzed polymer of the above composition= 31 7 % K) The lower value

actually found merely emphasizes the insoluble nature of the polymer whereby the 90 central portions of the powder particles were not exposed to the hydrolyzing medium The potassium salt is an effective ion-exchange resin When 2 gm of this salt was stirred for 2 hours with 100 cc of hard water ( 236 95 ppm Ca as the chloride) at room temperature and then filtered the calcium content in the water was reduced to less than 2 ppm. EXAMPLE H. 14.4 gm ( 0 057 mole) octadecene, 5 6 gm 100 ( 0.057 mole) maleic anhydride were dissolved in 30 gm dioxane and 15 cc benzene and irradiated in a Cobalt 60 source at room temperature and 250,000 R/hr for 24 hours (total dosage 6,000,000 R) After this treat 105 ment the solvents were evaporated on a steam bath under vacuum and the residue was washed thoroughly with methanol The methanol washings were discarded and the residue solidified to a waxy, water white 110 solid weighing 16 3 gm Theory for a 3/2 octadecene/maleic anhydride product is 18 6 gm yield The analyses calculated for this 3/2 molar ratio of octadecene/maleic anhydride are compared in the following 115 table to the values found by analysis. Found Calculated Mean % C 78 0 77 69, 76 80 = 77 25 % H 11 9 12 66, 12 32 = 12 49 120 % O 10 1 9 06, 11 48 = 10 27 0 100 01 This product, while having only limited oil solubility as such, can be readily hydro 125 lyzed and esterified to make it sufficiently soluble for use in lubricating oils Alternately, the product can be hydrolyzed and neutralized to give a salt useful as a soil conditioner 130 785,507


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