* GB786119 (A)

Description: GB786119 (A) ? 1957-11-13

Improvements in or relating to polymers and their uses

Description of GB786119 (A)

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PATENT SPECIFICATION 7869119 Date of Application and filing Complete Specification: Sept 26, 1955. N.27394155. Application made in United States of America on Oct 8, 1954. Complete Specification Published: Nov 13, 1957. Index at acceptance:-Classes 2 ( 3), B 4 B, C 2 B 37 A 3, C 2 D 43 (A: 54), C 3 A 1; 2 ( 6), P 1 A, P 1 C( 8 B: 8 C: 20 C: 20 D 2: 20 D 3), Pl D(IC; 1 X; 5); and 98 ( 2), M. International Classification:-CO 7 c, d CO 8 f G 03 f. COMPLETE SPECIFICATION Improvements' in or relating to 'Polymers, and their uses We, E I Du PONT DE NEM Ou RS AND COMPANY, a Corporation organised and existing under the Laws of the State of Delaware, United States of America, of Wilmington, Delaware, 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 new polymers capable of addition polymerization and more particularly to solvent-soluble linear polymers which contain extralinear ethylenically unsaturated groups and to their preparation and uses It further relates to solid polyacetals of essentially linear hydroxyl polymers having a plurality of intralinear vinyl alcohol (-CH CHOH-) groups and a plurality of extralinear vinylidene (CH 2 = C<) groups in a conjugated system of double bonds The invention also relates to polymerizable compositions containing such a polyacetal and an addition-polymerization initiator activatable by actinic light, and to sheet articles having a solid layer of such composition. According to a first feature of the present invention there is provided a solid polyvinyl acetal of a linear polymeric alcohol of high molecular weight having a large number of intralinear -CH CHOH groups, said acetal containing a plurality of extralinear vinylidene groups (Cil = C<) in a conjugated double bond system More particularly, according to the invention, there are provided solid polyacetals of essentially linear polymeric polyhydric alcohols having a large number of recurring intralinear -CH CHOH units, said polyacetals also comprising a plurality of extralinear vinylidene CH = C< groups, said groups being in conjugated systems of double bonds, i e, each having its double bond conjugated with another double bond, the ratio of acetal groups to vinylidene groups in the polymer being from about 10: 1 to about 1:10 Said polyacetals are soluble in solvents, e g, water, methanol, ethanol, acetone and dioxane and form self-supporting non-tacky films. In the description of the invention which follows, the polymeric polyhydric alcohol containing recurring intralinear -CHCHOHgroups will often be referred to for the sake of brevity, simply as a " polyvinyl alcohol " It will be understood that this term refers broadly to a material having a plurality of polymerized vinyl alcohol, -CHCHOIHunits, whether or not it is polyvinyl alcohol itself or one of a number of related derivatives which contain a large number of intralinear -CH CHOH groups, said material having in general a molecular weight above 5,000 and, preferably between 5,000 and 50,000. In a preferred form of the invention, the solid polyacetal is the reaction product of a polyvinyl alcohol with a terminally unsaturated aldehyde In this case, the aldehyde is so chosen that the resulting polyacetal has a vinylidene group in a conjugated system even though the aldehyde carbonyl is no longer present In other words, the aldehyde must contain a terminal conjugated system which is separate and independent from the aldehyde carbonyl, rather than a conjugated

system (as, for example, in acrolein or crotonaldehyde) which includes the aldehyde carbonyl, since acetalization of the latter would give an acetal no longer containing a conjugated system In polyacetals made solely from aldehydes containing a vinylidene group in a conjugated system independent from the carbonyl group, the ratio of acetal groups to vinylidene groups is necessarily the same as the ratio of carbonyl to vinylidene groups in the starting aldehyde, and is normally 1:1. In another important embodiment of the invention, the solid polyacetal is the reaction product of a polyvinyl alcohol with an aldehyde, which may be saturated or unsaturated, and with an unsaturated reactant, preferably an G-methylene carboxylic acid, capable of reacting withlthe hvdroxvliups of the polys vinyl alcohol and having a vinylidene group in a conjugated system of double bonds In polyacetals of this type, the ratio of acetal groups to vinylidene groups can vary widely; but for a good balance of properties, it should be within the range of about 10: 1 to about 1:10. The polyacetals of this invention always contain a plurality of vinylidine groups in conjugated double bond systems This type of structure has been found necessary for photopolymerization to take place at a practical rate. Polymers having unconjugated vinylidene groups, e g, allyl groups; or having conjugated unsaturation, but not including a vinylidene, i e, terminal methylene group, do not photopolymerize alone with the conventional initiators, or, if they do, the polymerization rate is too slow to be practical, especially for making printing reliefs Thus, the polyacetals of this invention contain groups CIL = C-, where R is hydrogen or a R monovalent radical, attached to an atom which is itself doubly bonded to another group (i e, single atom or radical) Preferably, the vinylidene group CH, = C is attached to carbon R itself doubly bonded to carbon or oxygen It is necessary that a plurality of such vinylidene groups be present in each polyacetal molecule in order for the addition polymerization to produce a cross linked structure. The unsaturated polyvinyl acetals of this invention have good film-forming properties, freedom from tackiness, resistance to physical deformation, toughness and chemical stability and molecular weights from 6,000 to 150,000. In the polyacetals defined above the polyhydric alcohol portion of the molecule is a hydroxyl polymer containing a large number of intralinear -CELCHOH groups that is soluble in cold and/or hot water or is hydrophilic in character, i e, forms films which do not dissolve but are freely water-permeable and swell Such a polymer can be, for example, polyvinyl alcohol itself, i e, a substantially completely hydrolyzed polyvinyl carboxylate; or it may be a partially hydrolyzed

polymer of a vinyl carboxylate, particularly a vinyl ester of a monocarboxylic acid of one to four carbon atoms, e g, vinyl formate, vinyl acetate, vinyl chloroacetate, vinyl propionate or vinyl butyrate The vinyl carboxylate should be sufficiently hydrolyzed so that the -CH CHOH groups represent at least 50 % of the polymer chain, i e, for every 100 chain atoms there are at least 25 hydroxyl groups Hydrolyzed interpolymers of vinyl esters with minor proportions ( 25 % or less by weight) of other polymerizable vinyl compounds, e g, vinyl chloride or methyl methacrylate are suitable In particular, the hydrolyzed olefin/vinyl esters interpolymers and especially the hydrolyzed ethylene/vinyl acetate interpolymer having hydrophilic properties described in Specification No 600,023 65 are useful The preferred starting materials are the 50-100 % 3 hydrolyzed polyvinyl acetates. In the polyvinyl acetals of this invention, it is preferred that between about 10 %,o and 70 about 90 %-', are still more preferably between %X O and 90 % of the hydroxyl groups of the polyvinyl alcohol are acetalized If less than about 10 %', of the hydroxyl groups be acetalized, the desired film toughness and resiliency 75 characteristic of the polyvinyl acetals are not realized, even when many of the non-acetalized hydroxyl groups are replaced by other groups, e g, acyl groups The higher limit of about 90 %,' acetalization is in the neighbour 80 hood of that obtainable by pushing the acetalization reaction to the maximum possible extent lsee the papers by P J Flory in J Am. Chem Soc 61, 1518 ( 1939) and 72, 5052 ( 1950), where it is shown by statistical analy 85 sis that reactions involving pairs of substituents X in a linear polymer composed of -CH 2-CHX units cannot go to completion l As has already been stated, the polyvinyl 90 acetals of this invention may contain substituents besides the acetal groups, such substituents being preferably saturated acyl groups and/or unsaturated acyl groups, the latter furnishing the necessary vinylidene 95 groups when the aldehyde furnishing the acetal groups contains no vinylidene groups. Other saturated or unsaturated substituents may also be present, e g, ether groups. Suitable inert substituents are carboxylic 100 ester groups, e g, acetate, propionate and nbutyrate groups (preferably acetate groups), which are originally present in the starting material, and acetal groups derived from saturated aldehydes, preferably aromatic alde 105 hydes such as benzaldehyde, o-chlorobenzaldehyde and p-benzoxybenzaldehyde In general, it is preferable that as many as possible of the hydroxyl groups of the polyvinyl alcohol be substituted in order to decrease the 110 water-sensitivity of the products The most useful compounds are those in which at least %,

preferably at least 85 %J O of the hydroxyl groups are substituted. The polyvinyl acetals of unsaturated alde 115 hydes may be prepared, for example, by reacting, under acetal-forming conditions, a polyvinyl alcohol with the appropriate aldehyde, or preferably with a monomeric acetal thereof, e g, an acetal of an alkanol of 1 to 4 120 carbon atoms, for example, methanol or ethanol, or of a 1,2 or 1,3 alkanediol of 1 to 4 carbon atoms, such as ethylene glycol and propylene glycol, until acetalization of the hydroxyl groups has proceeded to the desired 125 extent Thus the reaction can be carried out 786,119 786,119 3 at a temperature from 40 C to 150 C, in the presence of an acid, e g, hydrochloric, sulphuric, phosphoric, p-toluenesulphonic, methanesulphonic acetic, chloroacetic or trifluoroacetic acid for a period of 2 to 48 hours. When the last of these organic acids is used, a slight amount of esterification may take place Simultaneously with the acetalization reaction or subsequently, additional substituents, preferably saturated aliphatic acyl groups, can be introduced to decrease further the amount of unreacted hydroxyl groups. This can be done, for example, by carrying out the acetalization reaction in a solvent medium which consists of or comprises a saturated monocarboxylic acid, e g, glacial acetic acid, and may also contain the anhydride of the same acid to absorb the water formed in the reaction When it is desired to introduce the necessary vinylidene groups through reactants other than the aldehyde, for example, through an unsaturated carboxylic acid, this can be done by simultaneous or, if desired, successive acetalization and acylation of the polyvinyl alcohol with the appropriate dldehyde and the appropriate acid containing a vinylidene group in a conjugated system of double bonds The conventional acetalization and acylation procedures, catalysts and conditions can be used. Suitable unsaturated aldehydes are mentioned in the examples which follow Other unsaturated mono-aldehydes (i e, aldehydes having a vinylidene group in a conjugated structure independent of the aldehyde carbonyl) which can be reacted, as such or in the form of a monomeric acetal of a simple monohydric or dihydric alcohol, e g methanol, ethanol or ethylene glycol, with a polymeric polyhydric alcohol to form a polyvinyl acetal, include acrylamidoacetaldehyde, CH 2 = CH-CO-NH-WC CHO;, (methacrylamido) propionaldehyde, CH 2 = CHCO-NH-C Ho-C Ho-CHO; oc-vinylcrotonaldehyde, CHG = CH-C = C-CH,; CHO c'.-phenylacrolein, CHG = C-CHO; o-acrylyloxybenzaldehyde, C Gl = CH-CO-OQH,-CHO; m (a ethylacrylamido)benzaldehyde, CG Il = C-CO-NH-CGH 1CHO; 1-vinyl-4-naphthaldehyde, CH=CHZ c Ho 2-acrylamido-4-naphthaldehyde, CHO 4-vinyl-4 '-formylbiphenyl, and p-( 2-methacrylyloxyethoxy)benzaldehyde, CH = C-CO O c Hit 12 i-o HO CH 3

The preferred polyvinyl acetals are those derived from unsaturated aldehydes having from 5 to 15 carbon atoms and particularly those which are derived from an aromatic aldehyde, since films from such polyvinyl acetals and their addition polymers are harder and dimensionally more stable than others. Within this embodiment of the invention, the preferred polyvinyl acetals are those derived from aldehydes of the general formula: CG = C-(R)12 (X-Q),,-RW-CHO, where y Y is hydrogen or alkyl of one to two carbon atoms, i e, methyl or ethyl; R and R 1 are 70 aromatic carbocyclic radicals, preferably arylene; X is carbonyl, -CO-, or sulphonyl, -SO,-; Q is oxygen, -0-, or imino, -NH-; and m and N are 0 or 1, or their dimethyl, diethyl or ethylene glycol acetals 75 In the embodiment of the invention wherein the conjugated vinylidene unsaturation is furnished partly or entirely by a group other than the acetal group, the unsaturated radical can be any non-acetal radical containing a 80 vinylidene group which is part of a conjugated system of double bonds For example, it can be a carboxylic acid ester group, or a sulphonic acid ester group, or an ether group. Preferably, it is a carboxylic acid ester group, 85 e.g, the ester groups derived from acrylic, methacrylic, ac-ethylacrylic, j 3-vinylacrylics achloroacrylic, -phenylacrylic and p-vinylbenzoic acids The most useful of such unsaturated substituents are the ester radicals 90 corresponding to cc-methylene monocarboxylic acids, and particularly to such acids having from three to five carbon atoms In this type of polymers, the acetal groups can be supplied by any aldehyde, which may be saturated or 95 unsaturated (in which latter case conjugated vinylidene groups may be present in both the acetal group and the auxiliary, e g, ester groups) Suitable aldehydes include, for example, formaldehyde, acetaldehyde, propion 100 CH 2 = CH CHO 786,119 aldehyde, isobutyraldehyde, furfural, cyclohexylaldehyde, o-chlorobenzaldehyde, salicylaldehyde, cinnamaldehyde, phenyl acetaldehyde, the naphthaldehydes, 1-chloro-2naphthaldehyde, anthraldehydes and benzamidoacetaldehydes Preferably, the aldehyde furnishing the acetal groups is one having from one to fifteen carbon atoms and more preferably, it is an aromatic aldehyde of from seven to eleven carbon atoms in which the aldehyde group is directly attached to annular carbon of an aromatic carbocyclic ring. According to a further feature of this invention there are provided photopolymerisable compositions which comprise a polymeric polyvinyl acetal as previously set forth, in admixture with an addition polymerization initiator e g one which is activatable by actinic light of wavelengths from 1800 to 7000 A In order to increase the storage stability of the aforesaid compositions, it is desirable that they

contain a small amount, e.g, between 0 005 and 0 0201 by weight, of one of the known polymerization inhibitors such as hydroquinone or 4-hydroxydiphenyl. The said photopolymerizable compositions can be coated, cast or extruded into a selfsupporting film Such a film may be laminated to a suitable support or coated onto a suitable support, e g, metal sheet or plate, hydrophobic film, impregnated paper or cardboard, or laminated paper sheet and dried to remove water and/or an organic solvent The resulting sheet elements, which bear a photopolymerizable layer, can be used to prepare relief images, particularly printing reliefs. This invention accordingly includes photopolymerizable elements suitable for the preparation of printing relief images Thus, it has been found that letterpress printing plates which have uniform printing height can be prepared by exposing with actir'ic light through a process transparency, e g, a process negative or positive (an image-bearing transparency consisting solely of substantially opaque areas and substantially transparent areas where the opaque areas are substantially of the same optical density, the socalled line or halftone negative or positive) a photopolymerizable layer or stratum comprising an unsaturated polyvinyl acetal of this invention having intimately dispersed therethrough an addition polymerization initiator activatable by actinic light, said layer or stratum being superposed on a suitable adherent support, i e, adherent to the photopolymerized composition, until substantially complete crosslinking through the vinylidene groups take place in the exposed areas, while substantially none takes place in the non-exposed areas, and essentially completely removing the layer, e g, the non-crosslinked polymer together with any admixed material, in said non-exposed areas. The ethylenically unsaturated polyvinyl acetal layer being transparent to actinic light is photopolymerized, i e, crosslinked and rendered insoluble, clear through to the support in the light-exposed areas, whereas the areas not exposed remain in substantially their 70 original state, i e, no significant crosslinking takes place in the areas protected by the opaque images in the process transparency. The unexposed, and therefore non-crosslinked, material is then removed by treating 75 the layer with a solvent for the original poly vinyl acetal The crosslinked (exposed) portions being insoluble in practically all solvents remain unattacked, forming the relief image. The thickness of the photopolymerizable 80 layer is a direct function of the thickness desired in the relief image and this will depend on the subject being reproduced and particularly on the extent of the non-printing areas.

In the case of photopolymerized halftones, the 85 screen used is also a factor In general, the thickness of the polyvinyl acetal layer to be photopolymerized on the base plate will vary from 0 003 to 0 25 inch Layers ranging from 0.003 to 0 03 inch in thickness and usually 90 from 0 003 to 0 007 inch will be used for halftone plates Layers ranging from 0 01 to about 0.06 inch in thickness will be used for the majority of letterpress printing plates, including those wherein halftone and line images are 95 to be combined, and it is with these thicknesses that the process of this invention is particularly effective Layers thicker than 0 05 -0.06 inch will be used for the printing of designs and relatively large areas in letter 100 press printing plates. Actinic light from any source and of any type can be used in carrying out this process. The light may emanate from point sources or be in the form of parallel rays or divergent 105 beams In order to reduce the exposure time, however, it is preferred to use a broad light source, i e, one of large area as contrasted to a point source of light, close to the imagebearing transparency from which the relief 110 image is to be made By using a broad light source, relatively close to the image-bearing transparency, the light rays passing through the clear areas of the transparency will enter as divergent beams into the photopolymeriz 115 able layer, and will thus irradiate a continually diverging area in the photopolymerizable layer underneath the clear portion of the transparency, resulting in the formation of a polymeric relief which is at its greatest width at 120 the bottom surface of the photopolymerized layer, the top surface of the relief being the dimensions of the clear area Such relief images are advantageous in printing plates because of their greater strength and the 125 smooth continuous slope of their sides as contrasted to the undercut or jagged, irregular nature of the sides of photoengraved reliefs. This is of importance since the smooth sloping reliefs obtained in this process reduce or 130 786,119 eliminate the problem of ink-build-up that is always encountered with photoengraved plates. Inasmuch as the photopolymerization initiators or catalysts generally exhibit their maximum sensitivity in the ultraviolet waveband, the light source should furnish an effective amount of this radiation Such sources include carbon arcs, mercury vapour arcs, fluorescent lamps with special ultraviolet-light-emitting phosphors, argon glow lamps, and photographic flood lamps Of these, the mercury vapour arcs, particularly the sunlamp type, and the fluorescent sunlamps are most suitable Groups of these lamps can be easily arranged to furnish the broad light source required to give a frustrumshaped relief image of good mechanical strength The sunlamp mercury vapour arcs are

customarily used at a distance of 7 to 10 inches from the photopolymerizable layer On the other hand, with a more uniform extended source of low intrinsic brilliance, such as a group of contiguous fluorescent lamps with special phosphors, the plate can be exposed within an inch of the lamps. The base material used can be any natural or synthetic product, capable of existence in film or sheet form and can be flexible or rigid, reflective or non-reflective of actinic light. Because of their generally greater strength in thinner form, e g, foils, and readier adaptabilityfor usein printingpresses,it ispreferable to use metals as the base materials However, where weight is critical, the synthetic resins or superpolymers, particularly the thermoplastic ones, are preferable base materials In those instances where rotary press plates are desired both types of base or support materials can be used to form flat relief plates which are then formed to the desired shape The thermoplastic resins or high polymers are particularly suitable base materials in such uses. Such rotary press plates can also be prepared by using cylindrically shaped base plates carrying the photopolymerizable compositions and exposing them directly through a concentrically disposed image-bearing transparency in like manner. Suitable base or support materials include metals, e g, steel, zinc and aluminium plates including grained zinc or aluminium plates, sheets and foils, and films or plates composed of various film-forming synthetic resins or high polymers, and in particular the vinylidene polymers, e g, the vinyl chloride polymers, vinylidene chloride copolymers with vinyl chloride, vinyl acetate, styrene, isobutylene and acrylonitrile; and vinyl chloride copolymers with the latter polymerizable monomers; the linear condensation polymers such as the polyesters, e g, polyethylene terephthalate; the polyamides, e g, polyhexamethylenesebacamide; polyester amides, e g, polyhexamethyleneadipamnide/adipate Fillers or reinforcing agents can be present in the synthetic resin or polymer bases, such as fibres (synthetic, modified, or natural), e g, cellulosic fibres, for instance, cotton, cellulose acetate, viscose rayon, paper, glass wool or 70 nylon These reinforced bases may be used in laminated form. When highly reflective bases and particularly metal base plates are used, any oblique rays passing through clear areas in the image 75 bearing transparency will strike the surface of the base at an angle other than 90 and after resultant reflection will cause polymerization in non-image areas The degree of unsharpness in the relief progressively increases 80 as the thickness of the desired relief and the duration of the exposure increases It has been found that this disadvantage can be overcome when the photopolymerizable composition

is deposited on a light-reflective base by 85 having an intervening stratum sufficiently absorptive of actinic light so that less than 351,' of the incident light is reflected This lightabsorptive stratum must be adherent to both the photopolymerized image and the base mat 90 erial A practical method of providing the layer absorptive of reflected light, or non-halation layer, is to disperse a finely-divided dye or pigment which substantially absorbs actinic light in a solution or aqueous dispersion of a 95 resin or polymer which is adherent to both the support and the photopolymerized image and coating it on the support to form an anchor layer which is dried If desired, where a transparent film or plate is used as a support for the 100 photopolymerizable layer, the antihalation layer may be disposed. For use as photopolymerizable layers or printing relief images, the compositions of this invention may contain, in addition to the un 105 saturated polyvinyl acetals, photopolymerizable monoethylenic monomers which, when converted to linear polymers, serve to improve the properties of the relief image, such as its solvent resistance Such additional materials in 110 dude mono-unsaturated vinylidene monomers, particularly the acrylic and a-alkylacrylic esters, nitriles and amides, and specifically the acrylamide and methacrylamide These additional components are preferably used in 115 amounts between 51 % and 35 % of the weight of the total composition In use, they photopolymerize in the exposed portions of the lightsensitive layer, and any unpolymerized (i e, unexposed) portion of these added monomers 120 is readily removed by solvent treatment at the same time as the non-crosslinked portions of the unsaturated polyvinyl acetal. The photopolymerizable layers may also, if desired, comprise other compatible monomeric 125 or polymeric poly-unsaturated materials which, under the influence of actinic light, polymerize to crosslinked insoluble polymers These agents improve the rate or extent of the crosslinking throughout the photopolymerizable layer, and 130 their presence facilitates the removal of the unexposed areas; they also serve to plasticize the compositions when an initially softer composition is desired A useful class of such matS erials are the monomers or low polymers containing two terminal ethylenic unsaturations, preferably in conjugated systems Suitable examples are the methacrylic and acrylic acid diesters of ethylene glycol, diethylene glycol, and the low molecular weight polyethylene glycols; methacrylic and acrylic acid diesters of polymethylene glycols such as trimethylene glycol; hexamethylene glycol, etc; divinylbenzene, crotyl methacrylate, diallyl phthalate, diallyl maleate and triallyl cyanurate These additional crosslinking agents are preferably used in amounts between 1,% and 40 % by weight of the total compositions.

The photopolymerizable layers may also contain immiscible polymeric or non-polymeric organic or inorganic fillers or reinforcing agents which are essentially transparent, e g, the organophilic silicas, bentonites, silica and nowdered glass, having a particle size less than O 4 mil and in amounts varying with the desired properties of the photopolymerizable layer. Even when containing monomeric or low polymeric additives as described above, the photopolymerizable compositions of this invention are solids While their hardness varies from medium hard to very hard, they are nevertheless substantially non-deformable under ordinary conditions, and non-tacky Thus, they offer considerable physical advantages over photopolymerizable compositions obtained as liquids, viscous liquids or semi-solid gels from the standpoint of forming into convenient elements for commercial printing use. Practically any initiator or catalyst of addition polymerization which is capable of initiating polymerization under the influence of actinic light can be used in the photopolymerizable polymer-initiator layer of this invention. Because transparencies transmit both heat and light and the conventional light sources give off heat and light, the preferred initiators of addition polymerization are not activatable thermally They should be dispersible in the unsaturated polyvinyl acetal to the extent necessary for initiating the desired polymerization under the influence of the amount of light energy absorbed in relatively short term exposures Precautions can be taken to exclude heat rays so as to maintain the photopolymerizable layer at temperatures which are not effective in activating the initiator thermally, but they are troublesome In addition, exclusion of heat rays makes necessary longer exposure times since the rate of chain propagation in the polymerization reaction is lowered at reduced temperatures For this reason, the photoinitiators most useful for this process are those which are not active thermally at temperatures belowabot 800 C These photopolymerization initiators are used in amounts of from 0 05 to 51 % and preferably from 0 1 to 2 0 % based on the weight of the total photopolymerizable composition. Suitable photopolymerization initiators or catalysts include vicinal ketaldonyl compounds 70 such as diacetyl and benzil; 9-k-etaldonyl alcohols such as benzoin and pivaloin; acyloin ethers such as benzoin methyl or ethyl ethers; ot-hydrocarbon substituted aromatic acyloins including o methyl-benzoin, oa-allylbenzoin, and 75 2.-phenylbenzoin. The solvent liquid used for washing or "developing " the plates made from the photopolymerizable compositions of this invention must be such that it has good solvent action on 80 the linear, i e, non-crosslinked, polyvinyl acetal, and has little action on the

hardened image or upon the base material, non-halation layer, or anchor layer in the time required to remove the non-crosslinked portions Methanol 85 or ethanol, particularly the former, and mixtures thereof with methyl or ethyl or propyl acetate, and especially ethyl acetate/ethanol mixtures, have been found to be well suited for a large variety of pliotopolymerizable com 90 positions A blend of about 75/25 by weight of ethyl acetate and ethanol has a boiling range which is satisfactory since it is high enough to avoid blushing but at the same time is low enough that excess solvent evaporates readily 95 Alcohol/water mixtures, e g, methanol/water mixtures, are desirable solvents in some cases. Low aliphatic ketones such as acetone, acetone/ water mixtures, e g, an 8/1 mixture, and methyl ethyl ketone are very satisfactory sol 100 vents, as is also dioxane Other solvents such as propyl acetate, toluene, ethylene glycol monoethyl ether and mixtures thereof, are suitable but are not as convenient to use because of their lower evaporation rate Mixtures of 105 chlorinated aliphatic hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride with methanol are also useful, though less generally so. By the use of the photopolyrnerizable com 110 positions of this invention there is provided a simple, effective process for producing letterpress printing plates from inexpensive materials and with a marked reduction in labour requirements over the conventional photoen 115 graving procedure The images obtained are sharp and show fidelity to the original transparency both in small details and in overall dimensions In addition, the process allows the preparation of many types of ruled line plates 120 which could ordinarily be handled only by the tedious wax engraving technique Moreover, these photopolymerized plates allow much more efficient use of valuable press time since the flatness of the printing surfaces reduces the 125 amount of make-ready required on the press. The smooth clean shoulders of the image minimize ink build-up during use and save much of the time spent in cleaning operations during a press run Another important advantage arises 130 786,119 706,119 from the fact that the resilience and abrasion resistant characteristics of the photopolymerized printing plates make the plate more durable in use than ordinary metal photoengravings In fact, under optimum conditions the photopolymerized printing plates show wear resistance equivalent to that of the expensive nickel-faced electrotypes An important commercial advantage is their lightness in weight. The photopolymerized printing plates can serve as originals for the preparations of stereotypes or electrotypes although in the latter case if only duplicates are desired, it is much more convenient and economical to make duplicate photopolymerized plates Curved plates for

use on rotary presses can be prepared easily by bending the flat plates It may be desirable in some cases to heat the plates sufficiently (generally from 100 to 1200 C) to soften the image layer It is also possible to prepare curved plates directly by polymerization against a curved negative surface. The printing elements of this invention can be used in all classes of printing but are most applicable to those classes of printing wherein a distinct difference of height between printing and non-printing areas is required These classes include those wherein the ink is carried by the raised portion of the relief such as in dry-offset printing, ordinary letterpress printing, the latter requiring greater height differences between printing and non-printing areas and those wherein the ink is carried by the recessed portions of the relief such as in intaglio printing, e g, line and inverted halftone The plates are useful for multicolour printing. The use of compositions containing the unsaturated polyvinyl acetals of this invention as photopolymerizable printing relief elements has been described at length in view of its importance These acetals, however, are also suitable for many other applications in which readily crosslinkable polymers are useful, such as the preparation of filaments, foils, coatings, pellicles, sheets and other shaped or cast objects of excellent hardness and scratch resistance. The following examples will serve to illustrate various aspects of the present invention but are not to be regarded as limiting it in any 5) way, the parts given are by weight. EXAMPLE I. A Preparation of rn-Methacrylamidobenzaldehyde Ethylene Glycol Acetal. To a mechanically stirred solution of 50 parts of rn-aminobenzaldehyde ethylene glycol acetal (Specification No 638,895) in 40 parts of acetone and 5 parts of ice, there was added dropwise a solution of 31 parts of methacrylyl chloride in 30 parts of anhydrous dioxane The temperature was maintained at 0-5 C by means of external cooling and the p H of the reaction was kept at 7-9 by the portionwise addition of a solution of 50 parts of potassium carbonate and 50 parts of water The reaction product, mn methacrylamidobenzaldehyde 65 ethylene glycol acetal, separated as a colourless crystalline solid The reaction mixture was stirred for an additional period of 30 minutes and was diluted to a volume of 500 parts with cold water The m-methacrylamidobenzalde 70 hyde ethylene glycol acetal was collected and washed with cold water and the moist filter cake was dissolved in methylene chloride The organic layer was separated, dried with anhydrous magnesium sulphate and concentrated 75 by evaporation of the solvent until the internal temperature reached 48 C The mixture was cooled slightly and diethyl ether was added until crystals appeared

After cooling to O C. the colourless crystals of m-methacrylamido 80 benzaldehyde ethylene glycol acetal were collected, washed with cold diethyl ether and dried The yield of colourless crystals melting at 113-114 C was 50 parts. Anal Calc'd for CH 11,ON: C, 66 92; 85 11, 6 49; N, 6 01 Found C, 66 67; H, 6 64; N, 6 06. B Preparation of m-Methacrylamidobenzaldehyde Polyvinyl Acetal. A mixture of 5 parts of an 86-90 % hydro 90 lyzed polyvinyl acetate having a viscosity of 4-6 centipoises (for a 41 % water solution at C) (a polyvinyl alcohol commercially sold under the trade mark " Elvanol " 51-05), 2 parts of mn methacrylamidobenzaldehyde 95 ethylene glycol acetal (sufficient to react with about 19 % of the hydroxyl groups present), 20 parts of glacial acetic acid, 1 5 parts of trifluoroacetic acid, and 0 03 part of hydroquinone was stirred at 85 C for 1 5 hours The m 100 methacrylamidobenzaldehyde polyvinyl acetal was precipitated from the resulting pale yellow solution by addition of about 30 parts of diethyl ether followed by the addition of 20 parts of petroleum ether The solvents were decanted 105 from the precipitated product and the heavy, gummy mass was washed with ether The precipitated polyvinyl acetal was dissolved in about 15 parts of methanol and reprecipitated by the addition of 30-40 parts of ether The 110 solution and precipitation processes were repeated a second and third time After the third precipitation from methanol, the m-methacrylamidobenzaldehyde polyvinyl acetal was dissolved in methanol and the resulting solution 115 was filtered, the filtered solution coated on a glass plate and the methanol was allowed to evaporate leaving a colourless, transparent, flexible film The nitrogen content of the solvent free polymer was 1 91 %, indicating that 120 essentially all of the monomeric m-methacrylamidobenzaldehyde ethylene glycol has been converted to the polyvinyl acetal This polymer was a polyvinyl acetal containing, besides unreacted hydroxyl groups in intralinear 125 -CH CHOH groups, m-methacrylamidobenzaldehyde acetal groups of the structure: ci-Cai Cu Cii-c I 0 O ctj Lt N-co-f =Cfi 2 CH 3 and acetoxy groups, the latter being present in the original partially hydrolyzed polyvinyl acetate and also resulting from esterification during the acetalization reaction The polymer was soluble in methanol, ethanol and ethylene glycol but was insoluble in esters, e g, ethyl acetate and methyl acetate, and was insoluble in water. C Preparation of Printing Relief Images. To a methanol solution of the m-methacrylamidobenzaldehyde polyvinyl acetal, prepared as described under Section B, there was added 1,' of the solids content of benzoin methyl ether There was also added 0 01 %, based on the solids content, of hydroquinone to prevent premature

polymerization and insolubilization. The resulting solution was cast on glass plates to give films having a thickness of 0 010-0 020 inches after evaporation of the solvent The methanol was allowed to evaporate at room temperature in subdued light The resulting solid, transparent, tack-free films adhered tenaciously to glass The polyvinyl acetal layer was placed in intimate contact with a suitable line negative, the resulting assembly was placed on a turntable on a piece of black paper-toserve as an antihalation layer and exposed for a period of 15 minutes under four mercury vapour sunlamps suitably arranged at a distance of 12-14 inches from the surface of the layer After removal of the negative, the unexposed material was removed by washing in methanol for 5-10 minutes The resulting plate had scratch-resistant printing relief images of excellent sharpness having deep recess areas. EXAMPLE II. A Preparation of p-Vinylbenzaldehyde Ethylene Glycol Acetal. To a mechanically stirred solution of 27 parts of 85 % potassium hydroxide in 160 parts of 95 M% ethanol at 600 C was added 80 parts of p ( 2-bromoethyl)benzaldehyde ethylene glycol acetal The temperature rose to 70 C. and crystals of potassium bromide separated. The reaction mixture was maintained at 70 C for 15 minutes and most of the ethanol was removed by distillation under reduced pressure. The residue was diluted with water, the organic material was extracted with diethyl ether and after concentration of the ether extract, the residual Pf-vinylbenzaldehyde ethylene glycol acetal was distilled The fraction boiling at 1050 C at 1 mm was recovered as substantially pure p-vinylbenzaldehyde ethylene glycol acetal. Anal Calc'd for,1 IH O 2: C, 74 96; H, 6.87 Found: C, 75 19; H 7 29. B Preparation of p-Vinylbenzaldehyde Polyvinyl Acetal. A mixture of 5 parts of the hydrolyzed polyvinyl acetate used in Example I, 2 5 parts of p-vinylbenzaldehyde ethylene glycol acetal (sufficient to react with about 32 %o of the hydroxyl groups present), 20 parts of glacial acetic acid, 1 5 parts of trifluoroacetic acid and 0 03 part of hydroquinone was stirred at 85-87 ' C for two hours The p-vinylbenzaldehyde polyvinyl acetal thus obtained was freed of hydroquinone and acetic acid essentially as described in Example I, Section B This polymer was a polyvinyl acetal containing, besides residual hydroxyl groups in intralinear -CGI GCHOH groups, acetoxy groups from the starting material and from further esterification by the acetic acid, and p-vinylbenzaldehyde acetal units of the formula: CH-Clif C A-CH 2 \ / CH=C"I" In the latter groups, the vinylidene group is conjugated with a benzenoid double bond. C Preparation of Printing Relief Images.

To the methanol solution of p-vinylbenzaldehyde polyvinyl acetal obtained as described under Section B was added 0 07 parts of benzoin methyl ether and 0 01 %, by weight of the solids content, of hydroquinone to stabilize against premature gelation, and the resulting solution was cast on glass plates After removal of the methanol by evaporation, a transparent, hard film was obtained that adhered tenaciously to glass Exposure under a suitable line negative and removal of unexposed material essentially as described in Example I, Section gave scratch-resistant printing relief images of excellent sharpness having deep recess areas. EXAMPLE III. A Preparation of mz-(p-Vinylbenzenesulphonamido)benzaldehyde Ethylene Glycol Acetal. To a solution of 150 parts of m-aminobenz 100 aldehyde ethylene glycol acetal, 240 parts of acetone, 150 parts of water and 150 parts of potassium carbonate at 5-7 ' C, there was added the sulphonyl chloride obtained by the chlorosulphonation of 200 parts of ( 2-brom 105 ethyl)benzene as described by Inskeep and Deanin, I Amt Chen Soc 69, 2237 ( 1947). The resulting reaction mixture was stirred at 5-10 C for 20 hours; it was then diluted with water and the liquid organic layer was 110 786,119 recess areas An excellent relief printing image was obtained by adding to the photopolymerizable composition 25 % (based on the weight of 60 the polyvinyl acetal) of the bis-methacrylate ester of polyethylene glycol of average molecular weight 200, as a plasticizer and additional crosslinking agent. EXAMPLE IV 65 A Preparation of m-Methacrylamidobenzaldehyde Polyvinyl Acetal Containing Acrylyloxy Groups. A mixture of 10 parts of the hydrolyzed polyvinyl acetate used in Example I, 4 parts of 70 m-methacrylamidobenzaldehyde ethylene glycol acetal (enough to react with about 19 % of the hydroxyl groups present), 40 parts of acrylic acid (a large excess over the calculated amount), 3 parts of trifluoroacetic acid and 75 0.06 part of hydroquinone was stirred at 90950 C for three hours The resulting polymer was freed of excess hydroquinone and acrylic acid essentially as described in Example I, Section B Evaporation of the methanol solu 80 tion gave a clear hard film This polymer was a polyvinyl acetal containing, besides hydroxyl groups in intralinear -CH CHOH groups, acetoxy groups, acrylyloxy groups and mmethacrylamidobenzaldehyde acetal groups 85 B Preparation of Printing Relief Images. To 50 parts of the methanol solution containing approximately 16 parts of the above polyvinyl acetal was added 0 18 part of benzoin methyl ether and about 0 0015 part of hydro 90 quinone and the resulting

solution was cast on glass plates After removal of the methanol at room temperature in subdued light, the layer of solid polymer was exposed under a line negative and unexposed material was removed 95 essentially as described in Example I, Section C Scratch-resistant printing relief images of excellent sharpness with deep recess areas remained adherent to the surface of the glass plate after removal of the unexposed material 100 EXAMPLE V. A Preparation of Benzaldehyde Polyvinyl Acetal Containing Acrylyloxy Groups. A mixture of 10 parts of the hydrolyzed polyvinyl acetate used in Example I, 40 parts of 105 acrylic acid (a large excess), 1 2 parts of benzaldehyde (enough to react with about 12 % of the hydroxyl group), 3 parts of trifluoroacetic acid and 0 03 part of hydroquinone was stirred at 90-95 C for three hours The resulting 110 polymer was freed of excess hydroquinone, acrylic acid and benzaldehyde essentially as described in Example I, Section B This polymer was a polyvinyl acetal containing, in addition to hydroxyl groups in intralinear 115 -CHCHOH groups, acetoxy groups, acrylyloxy groups and benzaldehyde acetal groups In this case, the vinylidene unsaturation was provided solely by the acrylyloxy groups 120 B Preparation of Printing Relief Images. separated and washed with water by decantation The resulting low-melting m-lp-( 2bromoethyl) benzenesulphonamidolbenzaldehyde ethylene glycol acetal, without further purification, was added to a solution of 165 parts of 85 % potassium hydroxide in 700 parts of 95 i% ethanol at 50 C The temperature rose to 67 C and crystals of potassium bromide separated After the mixture had been maintained at 65-69 C for 65 minutes, most of the ethanol was removed by distillation under reduced pressure and the residue was diluted with water The resulting solution was acidified by the addition of acetic acid, whereupon an oil separated that soon solidified Crystallization of the solidified product from a large volume of methylene chloride gave 145 parts of colourless crystals of m-(p-vinylbenzenesulphonamido)benzaldehyde ethylene glycol acetal, melting at 140-142 C. Anal Calc'd for C 17 H,0 NS C, 6159; H, 5 18; N, 4 23; S, 9 68 Found: C, 61 80; H, 5 14; N, 4 03; S, 9 59. B Preparation of m-(p-Vinylbenzenesulphonamido)benzaldehyde Polyvinyl Acetal. A mixture of 25 parts of the hydrolyzed polyvinyl acetate used in Example I, 15 parts of m-(p-vinylbenzenesulphonamido)benzaldehyde ethylene glycol acetal (sufficient to react with about 201 % of the hydroxyl groups present), 100 parts of glacial acetic acid, 7 5 parts of trifluoroacetic acid and 0 2 part of hydroquinone was stirred at 85-87 C for two hours The resulting

m-(p-vinylbenzenesulphonamido)benzaldehyde polyvinyl acetal was freed of excess hydroquinone and acetic acid essentially as described in Example I, Section B This polymer was a polyvinyl acetal having, besides residual hydroxyl groups in intralinear -CHCHOH-, groups, acetoxy groups and acetal groups of the formula: 0 \ O -C,-NH 2-5 2 C D-H 2 H C Preparation of Printing Relief Images. To 30 parts of the methanol solution containing approximately 12 parts of m-(p-vinylbenzene sulphonamido)benzaldehyde polyvinyl acetal prepared as described under Section B, there was added 0 12 part of benzoin methyl ether and about 0 001 part of hydroquinone and the solution was cast on glass plates After evaporation of the methanol, a transparent, non-tacky solid layer was obtained that adhered tenaciously to glass Exposure under a suitable line negative and removal of unexposed material essentially as described in Example I, Section C, gave a scratch-resistant printing relief image of excellent sharpness having deep 786,119 To the methanol solution of the above polyacetal was added 0 18 part of benzoin methyl ether and O 01 % of hydroquinone, based on the solids content, and the resulting solution was cast on glass plates After removal of the methanol by evaporation at room temperature, a non-tacky solid layer was obtained Exposure under a suitable negative and removal of unexposed material essentially as described in Example I, Section C, gave soft, highly resilient images. EXAMPLE VI. A Preparation of mii-Methacrylamidobenzaldehyde Polyvinyl Acetal. A mixture of 50 parts of the polyvinyl alcohol (hydrolyzed polyvinyl acetate) used in Example I, 37 5 parts of rn-methacrylamidobenzaldehyde ethylene glycol acetal (sufficient to react with about 361 % of the hydroxyl groups present), 200 parts of glacial acetic acid, 15 parts of trifluoroacetic acid and 0 3 parts of hydroquinone was stirred at 85-87 C for one hour Twenty ( 20) parts of acetic anhydride was added dropwise during the course of 30 minutes and the reaction was continued for an additional period of 30 minutes The polyvinyl acetal was freed of excess hydroquinone and acetic acid essentially as described in Example I, Section B There was obtained 300 parts of solution of the polyvinyl acetal containing 31 '% solids The solid had a nitrogen content of 2 41 % (theoretical 2 42 %) This polymer was essentially similar to that of Example I except that both the extent of acetalization and the extent of acetylation were higher From the weight of polyvinyl acetal obtained and its nitrogen content, it was calculated that it contained, by weight, 44 5 % of nt methacrylamidobenzaldehyde polyvinyl acetal, 46 C% of polyvinyl acetate and 9 5 % of polyvinyl alcohol This polymer was, therefore, a polyvinyl alcohol in which about 31 % of the hydroxyl groups were

acetalized and about 501 % of them acetylated. B Preparation of Printing Relief Images. To 20 parts of the above solution was added 0.06 part of benzoin methyl ether and 0 01 % of hydroquinone, based on the solids content, and the solution as cast on glass plates Removal of the methanol by evaporation at room temperature gave clear hard films having a thickness of 0 028-0 30 inch Exposure of the polymer under a line negative and removal of the unexposed material essentially as described in Example I, Section C, gave scratch-resistant printing relief images of excellent sharpness with deep recess areas A similar printing relief was obtained when 20 parts of the methanol solution of the m-methacrylamidobenzaldehyde polyvinyl acetal was mixed with 0 08 part of benzoin methyl ether and 1 8 parts of the bismethacrylate ester of a polyethylene glycol of average molecular weight 200, to act as plasticizer and additional crosslinking agent. The next three examples illustrate the use of a photopolymerizable monomer in admixtures with the addition-polymerizable polyvinyl acetal in elements suitable for the preparation of printing relief images The resulting compositions had faster photopolymerization rates 70 than the unmodified ones and the images were more solvent-resistant. EXAMPLE VII. To 20 parts of a methanol solution of a mmethacrylamidobenzaldehyde polyvinyl acetal 75 containing 44 {% solids and prepared essentially as described in Example I, there was added 0 1 part of benzoin methyl ether, about 0.0009 part of hydroquinone and 2 parts of acrylamide The resulting solution was cast on 80 glass plates and after removal of the methanol by evaporation at room temperature, a clear, hard, non-tacky film 0 015-0 020 inch thick was obtained Exposure of the film under a line negative and removal of unexposed material 85 essentially as described in Example I, Section C, gave a scratch-resistant printing relief image of excellent sharpness with deep recess areas. EXAMPLE VIII. To 10 parts of a methanol solution of a m 90 methacrylamidobenzaldehyde polyvinyl acetal containing 40 % solids and prepared essentially as described -in Example I, there was added 0 12 part of benzoin methyl ether, about 0.0004 part of hydroquinone, 0 5 part of acryl 95 amide and 0 5 part of methacrylamide The re sulting solution was cast on glass plates at such a thickness as to give films having a thickness of 0 015-0025 inch after removal of the methanol by evaporation at room temperature 100 Exposure of the resulting hard, non-tacky, transparent film under a negative and removal of the unexposed material essentially as described in Example I, Section C, gave scratchresistant printing relief images of excellent 105

sharpness with deep recess areas. EXAMPLE IX. To 20 parts of the same methanol solution as used in Example VIII, there was added 0 65 part of benzoin methyl ether, about 0 0008 part 110 of hydroquinone, 1 7 parts of the bis-methacrylate ester of polyethylene glycol (average molecular weight 200) and 1 part of acrylamide The resulting solution was cast on glass plates at such a thickness as to give films hav 115 ing a thickness of 0 025-0 030 inch, after removal of the methanol by evaporation at room temperature Exposure of the resulting hard, non-tacky, transparent film under a line negative and removal of the unexposed material 120 essentially as described in Example I, Section C, gave scratch-resistant printing relief images of excellent sharpness with deep recess areas. EXAMPLE X. A Preparation of n-Butyraldehyde Polyvinyl 125 Acetal Containing Methacrylyloxy Groups. A mixture of 5 parts of the polyvinyl acetal obtained by acetalizing polyvinyl alcohol with n-butyraldehyde until about 80 %c, of the hydroxyl groups are reacted, 25 parts of meth 130 786,119 vents at room temperature Exposure of the resulting hard, transparent film under a line negative and removal of the unexposed material essentially as described in Example I, Section C, except that a mixture of methylene chlorideethanol was used in place of methanol, gave hard printing relief images of excellent sharpness. acrylic acid, 1 5 parts of trifluoroacetic acid and 0 05 part of hydroquinone was stirred at 85-90 C for one hour The polymer was precipitated from the resulting clear solution by the addition of ether and freed of excess hydroquinone and methacrylic acid essentially as described in Example I, Section B Evaporation of a test portion of the methanol solution on a glass plate gave a colourless, transparent, tough film This polymer was a polyvinyl acetal containing, besides hydroxyl groups in intralinear -CH 2 CHOH groups, methacrylyloxy groups and n-butyraldehyde acetal groups. B Preparation of Printing Relief Images. To the methanol solution of the polyvinyl acetal prepared as described in Section A, there was added 0 05 part of benzoin methyl ether and 0 01 % of hydroquinone, based on the solids content, and the resulting solution was cast on glass plates to form films having a thickness of 0.010-0 015 inch, after removal of the methanol by evaporation at room temperature Exposure of the resulting hard, transparent film under a line negative and removal of the unexposed material essentially as described in Example I, Section C, gave images which, while useful as printing reliefs, were slightly attacked by the methanol used to removed the unexposed material.

EXAMPLE XI. A Preparation of m-Methacrylamidobenzaldehyde Polyvinyl Acetal. A mixture of 5 parts of the polyvinyl alcohol used in Example I, 20 parts of m-methacrylamidobenzaldehyde ethylene glycol acetal (nearly twice the amount calculated to react with all the hydroxyl groups present), 20 parts of ethanol, 0 1 part of hydroquinone and 0 5 part of a 10 % aqueous solution of sulphuric acid was stirred at 60-65 C for one hour whereupon 2 5 parts of a 101 % solution of triethylamine in methanol was added To the resulting solution was added diethyl ether to precipitate the polyvinyl acetal The excess hydroquinone was removed essentially as described in Example I, Section B, except that a mixed solvent of 3 parts of methylene chloride and 1 part of ethanol, by volume, was used in place of the methanol in Example I, Section B. This polyvinyl acetal was similar in structure to that of Example I except that it contained less acetoxy groups and more acetal groups. Analysis of a portion of the solid polymer gave a nitrogen content of 4 241 % This shows that about 85 % of the available hydroxyl groups were acetalized, since complete acetalization would correspond to 4 96 % nitrogen. B Preparation of Printing Relief Images. To the methylene chloride-ethanol solution of the polyvinyl acetal prepared under Section A was added 0 02 part of benzoin methyl ether and 0 011 % of hydroquinone, based on the solids content, and the solution was cast on glass plates to give films having a thickness of 0 010-0 015 inch on evaporation of the solEXAMPLE XII. A Preparation of p-Vinylbenzaldehyde Poly 75 vinyl Acetal. A mixture of 5 parts of the polyvinyl alcohol used in Example I, 15 parts of p-vinylbenzaldehyde ethylene glycol acetal (nearly twice the amount calculated to react with all the 80 hydroxyl groups present), 20 parts of ethanol, 0.1 part of hydroquinone and 05 part of 10 Q% aqueous sulphuric acid was stirred at 60-65 C for one hour whereupon 2 5 parts of a 10 i% solution of triethylamine in methanol was 85 added The polyvinyl acetal was precipitated by the addition of diethyl ether and freed of excess hydroquinone essentially as described in Example I, Section B, except that a mixed solvent of 3 parts of ethyl acetate and 1 part of 90 ethanol, by volume was used in place of methanol Casting a test portion of the solution of the polyvinyl acetal on a glass plate gave a hard, transparent flexible film This polymer was similar in structure to that of Example II 95except that it contained less acetoxy groups and more acetal groups. B Preparation of Printing Relief Images. To the ethyl acetate-ethanol solution of the polyvinyl acetal prepared in Section A was 100 added 0 1 part of benzoin methyl ether and 0.011

% of hydroquinone, based on the solids content, and one-half of the solution was cast on glass plates to give films having a thickness of 0 010-0 015 inch after evaporation of the 105 solvents at room temperature To the remainder of the original polymer solution was added an additional quantity of 0 02 part of benzoin methyl ether and 1 7 parts of the bismethacrylate ester of polyethylene glycol of 110 molecular weight 200 This solution was also cast on glass plates as previously described The resulting hard, non-tacky films were exposed under a line negative and the unexposed material was removed essentially as described in 115 Example I, Section C, except that a mixed solvent, ethyl acetate-ethanol ( 3 to 1 by volume) was used in place of methanol Both compositions gave scratch-resistant printing relief images of good sharpness with deep recess 120 areas. EXAMPLE XIII. A Preparation of m-Methacrylamidobenzaldehyde/o-chlorobenzaldehyde Polyvinyl Acetal. A mixture of 15 parts of medium viscosity 125 completely hydrolyzed polyvinyl alcohol (commercially sold under the trade mark " Elvanol " 90-25), 13 parts of m-methacrylamidobenzaldehyde ethylene glycol acetal, 10 5 parts of a-chlorobenzaldehyde, 100 parts of glacial 130 786,119 acetic acid, 7 5 parts of trifluoroacetic acid, 30 parts of chloroform and 0 1 part of hydroquinone was stirred at 65 C for 1 5 hours. The polyvinyl acetal was freed of hydroquinone and acetic acid essentially as described in Example I, Section B, except that dioxane was used as the solvent in place of methanol There was obtained 198 parts of dioxane solution having a solids content of 19 % Analysis of a portion of the solvent-free film gave a nitrogen content of 2 401 % and a chlorine content of 5.88 % These figures indicate that the polymer contained 44 5 % rn-methacrylamidobenzaldehyde polyvinyl acetal, 353 % o-chlorobenzaldehyde polyvinyl acetal, 17 8 % of polyvinyl acetate and 2 81 % of unchanged polyvinyl alcohol This polymer was a polyvinyl alcohol derivative in which about 72 % of the hydroxyl groups were acetalized and about 22 % of them were acetylated. B Preparation of Printing Relief Images. To 53 parts of the above dioxane solution of the polyvinyl acetal was added 0 1 part of benzoin methyl ether and 0 001 part of hydroquinone and the solution was cast on glass plates Removal of the dioxane at room temperature in subdued light gave a clear, transparent flexible film Exposure of the film under a suitable line negative and removal of unexposed material essentially as described in Example I, Section C, gave a scratch-resistant image of excellent sharpness with deep recess areas.

EXAMPLE XIV. Preparation of m Methacrylamidobenzaldehyde/3,4-dichlorobenzaldehyde Polyvinyl Acetal. A mixture of 10 parts of completely hydrolyzed high viscosity polyvinyl alcohol (commercially sold under the trade mark " Elvanol " 72-60), 15 parts of rn-methacrylamidobenzaldehyde ethylene glycol acetal, 8 8 parts of 3,4-dichlorobenzaldehyde, 125 parts of glacial acetic acid, 7 5 parts of trifluoroacetic acid and 0 1 part of hydroquinone was stirred at 65 C for 1 5 hours On addition of diethyl ether to the vigorously stirred reaction mixture, the polyvinyl acetal separated as a finely divided solid The solid was collected, washed with diethyl ether and slurried for 15 minutes with diethyl ether The solid polymer was again collected and slurried for 30 minutes with diethyl ether, and the slurrying steps were repeated a third and fourth time with fresh ether to remove the hydroquinone and acetic acid. The resulting dry powder ( 25 parts) had a nitrogen content of 2 55 %, and a chlorine content of 9 781 % These figures indicate that the polymer contained 47 % rz-methacrylamidobenzaldehyde polyvinyl acetal, 33 9 i% 3,4-dichlorobenzaldehyde polyvinyl acetal, 12.4 % of polyvinyl acetate and 6 7 i% of unchanged polyvinyl alcohol This polymer was a polyvinyl alcohol in which about 69 % of the hydroxyl groups were acetalized and about % of them were acetylated The polymer was soluble in dioxane and chloroform-dioxane mixtures. EXAMPLE XV. A Preparation of Methacrylamidoacetaldehyde 70 Ethylene Glycol Acetal. To a solution of 31 parts of aminoacetaldehyde ethylene glycol acetal (prepared as described in Organic Syntheses, Vol 24, p 3) and 50 parts of water cooled to 0-5 C was 75 added dropwise a solution of 35 parts of methacrylyl chloride in 35 parts of dioxane. The p H of the reaction mixture was maintained at 7-9 by the portionwise addition of a solution of 42 parts of potassium carbonate 80 in 40 parts of water After the addition of the acid chloride was complete, the reaction mixture was allowed to warm to 250 C during the course of one hour and stirred an additional period of two hours at 250 C The 85 reaction mixture was extracted several times with ether, the ethereal solution was dried over magnesium sulphate and after filtering, the solution was concentrated Distillation of the residue from 0 1 part of hydroquinone gave 40 90 parts of methacrylamidoacetaldehyde ethylene glycol acetal boiling at 120-122 C at 1 mm. pressure. Anal Calc'd for C 8 H 1,0,N: C, 56 11; H, 7.66 Found: C, 56 34; H 7 75 95 B Preparation of Methacrylamidoacetaldehyde Polyvinyl Acetal.

A mixture of 10 parts of 86-89 %' hydrolyzed low viscosity polyvinyl alcohol, 14 parts of methacrylamidoacetaldehyde ethylene 100 glycol acetal, 0 3 part of hydroquinone, 50 parts of glacial acetic acid and 0 4 part of p-toluene-sulphonic acid monohydrate was stirred at 650 C for 1 25 hours A solution of 2.5 parts of 10 % triethylamine in methanol 105 was added to neutralize the sulphonic acid catalyst and the methacrylamidoacetaldehyde polyvinyl acetal was precipitated by the addition of diethyl ether and freed of hydroquinone and acetic acid essentially as described 110 in Example I, Section B There was obtained 58 parts of methanol solution of the polyvinyl acetal, having a solids content of 32 % The solid polymer had a nitrogen content of 5.21 % On the basis of these figures, the solid 115 polyvinyl acetal had a methacrylamidoacetaldehyde polyvinyl acetal content of 73 5 %, a polyvinyl acetate content of 19 % and unchanged polyvinyl alcohol content of 7 6 %. This polymer was a polyvinyl alcohol deriva 120) tive in which about 19 % of the intralinear -CHICHOH groups were acetylated and about 65 % of them were replaced by acetal units of the formula: -CH-CH p CH-CH 2 f o',CH 11 C Hif NH-CO,-C= CH 2 ONCM 786,119 786,119 C Preparation of Printing Relief Images. To 31 parts of the above methanol solution, there was added 0 1 part of benzoin methyl ether and 0 001 part of hydroquinone and the resulting solution was cast on glass plates. Removal of the methanol at room temperature in subdued light gave a clear, transparent flexible film Exposure under a suitable line negative essentially as described in Example I, Section C, gave hard, scratch-resistant printing relief images of excellent sharpness with deep recess areas. EXAMPLE XVI. A Preparation of p-Methacrylyloxybenzaldehyde. To a solution of 73 parts of p-hydroxybenzaldehyde and 71 parts of anhydrous triethylamine in 200 parts of methylene chloride, there was added dropwise, with stirring, a solution of 73 parts of methacrylyl chloride in parts of methylene chloride, the temperature being maintained at 15-20 C by means of external cooling The mixture was stirred at 20-25 C for an additional period of one hour after the addition of the acid chloride was complete 200 parts of water containing 10 parts of concentrated hydrochloric acid was added and the organic layer was separated and washed twice with 1 % hydrochloric acid After drying and adding 0 2 parts of hydroquinone, the solution was concentrated and the residue was distilled There was obtained 86 parts of p-methacrylyloxybenzaldehyde boiling at 115-120 C at 1 mm. and melting at 27-29 C. Anal Calc'd for Cj HJO,: C, 69 44; H, 5.30 Found: C, 69 49; H, 5 43.

B Preparation of p-Methacrylyloxybenzaldehyde Polyvinyl Acetal. A vessel containing a mixture of 10 parts of 86-89 % hydrolyzed polyvinyl acetate (a low viscosity polyvinyl alcohol), 25 parts of p methacrylyloxybenzaldehyde (an excess over the quantity required to acetalize all the hydroxyl groups), 80 parts of glacial acetic acid, 6 parts of trifluoroacetic acid, and 0 1 part of hydroquinone was placed in a water bath at 600 C After stirring for 10 minutes at a bath temperature of 58-60 C, the bath temperature was allowed to drop to 550 C. during the course of 5 minutes The reaction mixture was diluted with 20 parts of diethyl ether, the polyvinyl acetal was precipitated by the addition of a mixture of diethyl ether and petroleum ether, and freed of hydroquinone and acetic acid essentially as described in Example I, Section B, except that acetone was used as the solvent in place of methanol There was obtained 82 parts of acetone solution having a solids content of 27 % This polymer was a polyvinyl acetal containing, besides intralinear -CHCHOH groups and gcetoxy groups, acetal groups of the formula Ci-C Hf CH -C Hf0 a cho -co C= CH 2 CH 3 C Preparation of Printing Relief Images 65 To 37 parts of the above acetone solution of the polyvinyl acetal, there was added 0 1 part of benzoin methyl ether and 0 001 part of hydroquinone and the resulting solution was cast on glass plates Removal of the acetone at 70 room temperature in subdued light gave a clear, transparent film Exposure of the film under a suitable negative and removal of the unexposed material essentially as described in Example I, Section C, gave a hard-scratch 75 resistant image of excellent sharpness. Ex AMPLE XVII. Preparation of p-Methacrylyloxybenzaldehyde Polyvinyl Acetal. A mixture of 10 parts of medium viscosity 80 polyvinyl alcohol (completely hydrolyzed polyvinyl acetate), 25 parts of p-methacrylyloxybenzaldehyde (an excess over the quantity required to acetalize all the hydroxyl groups), parts of glacial acetic acid, 7 5 parts of 85 trifluoroacetic acid and 0 1 part of hydroquinone was stirred at 60 C for 10 minutes and then at 550 C for an additional period of minutes The polyvinyl acetal was precipitated by the addition of diethyl ether and the 90 hydroquinone and acetic acid were removed essentially as described in Example I, Section B The acetone solution ( 121 parts) had a solids content of 21 % Cast films containing 1 % by weight of benzoin methyl ether and 95 0.01 % of hydroquinone gave hard printing relief images of excellent sharpness on exposure under a suitable line negative and removal of unexposed material essentially as described in Example I, Section C Similar 100 results were obtained by substituting chloroform for the acetone, and substituting a high viscosity polyvinyl alcohol (i e, a completely

hydrolyzed polyvinyl acetate having a viscosity of 45-55 centipoises) for the medium 105 viscosity polyvinyl alcohol (which had a viscosity of 20-25 centipoises. EXAMPLE XVIII. A Preparation of o-Methacrylyloxybenzaldehyde 110 To a solution of 122 parts of salicylaldehyde and 111 parts of anhydrous triethylamine in 350 parts of methylene chloride, there was added dropwise with stirring a solution of 115 parts of methacrylyl chloride in 100 parts of 115 methylene chloride, the temperature being maintained at 15-20 C by means of external cooling The mixture was stirred at i 3 20-25 C for an additional period of one hour after the addition of the acid chloride was complete 300 parts of water containing parts of concentrated hydrochloric acid was added, the organic layer was separated and washed twice with 1 % hydrochloric acid. After drying and adding 0 3 % part of hydroquinone, the solution was concentrated and the residue was distilled There was obtained 162 parts of o-methacrylyloxybenzaldehyde, boiling range 105-110 C /1 mm. Anal Calc'd for Cl H,1,O 3: C, 69 44; H, 5.30 Found: C, 69 32; H, 5 52. B o-Methacryloxybenzaldelhyde Polyvinyl Acetal. A mixture of 10 parts of 86-89 % hydrolyzed low viscosity polyvinyl alcohol, 25 parts of a-methacrylyloxybenzaldehyde, 80 parts of glacial acetic acid, 6 parts of trifluoroacetic acid and 0 1 part of hydroquinone was stirred at 60-65 C for 15 minutes The reaction mixture was diluted with 20 parts of diethyl ether and the polyvinyl acetal was precipitated by the addition of a mixture of equal parts by volume of ether and petroleum ether The polymer was freed of hydroquinone and acetic acid essentially as described in Example I, Section B except that acetone was used as the solvent in place of methanol The acetone solution weighed 60 parts and had a solids content of 37 %. C Preparation of Printing Relief Images. To the above acetone solution, there was added O 22 part of benzoin methyl ether and 0 002 part of hydroquinone and the resulting solution was cast on glass plates Removal of the acetone at room temperature in subdued light gave a clear transparent film Exposure of the film under a suitable negative and removal of the unexposed material essentially as described in Example I, Section C gave a hard, scratch-resistant image of excellent sharpness Similar images were obtained from the polyvinyl acetal composition derived from o-methacrylyloxybenzaldehyde and ( 1) 8689 % hydrolyzed medium viscosity polyvinyl alcohol, ( 2) completely hydrolyzed medium viscosity polyvinyl alcohol and ( 3) completely hydrolyzed high viscosity polyvinyl alcohol. EXAMPLE XIX.

Thick films of the polyvinyl acetal of Example I were prepared by an extrusion process as follows: To 392 parts of a methanol solution containing 133 parts of the mnmethacrylamidobenzaldehyde polyvinyl acetal, there was added 1 35 parts of benzoin methyl ether, 0 005 part of hydroquinone, 160 parts of methanol and 100 parts of water The resulting clear solution was poured slowly into 12,000 parts of distilled water in which had been dissolved 30 parts of sodium bicarbonate. The polyvinyl acetal, ether and hydroquinone precipitated as a white mass which was gathered into a lump and kneaded to work out excess water and methanol The mixture at this stage was a coherent, opaque white mass which contained approximately 37 % by weight of solvent This dough was fed through a screw extruder with the barrel, head and die temperatures at 35-405 C A beading die was 70 used Large amounts of water were squeezed out during the first passage through the die and the extruded material was recycled, after which it emerged as a transparent amber cylindrical filament about -8 inch in diameter 75 The water content was approximately 20%, by weight At this point, the beading die was replaced by a film die which included a screen pack filter consisting of nvo 100 mesh screens between two 50 mesh screens The film 80 die, about 3 inches in width, was set with lips 0.034 " apart The transparent bead was passed into the extruder again, this time passing through the film die The film of polyvinyl acetal and initiator obtained was clear and flat 85 if a slight tension was kept on the film as it left the die lips The thickness of the extruded film was 0 035 to 0 050 inch depending on the exact amount of tension used and the width, about 3 inches Residual solvent was removed 90 by festooning the extruded film and drying in a current of air. Such extruded films were laminated to cold rolled steel base sheets 0 015 " thick by a hot pressing operation The steel sheets were pre 95 pared for this use by cleaning, spraying on a zinc chromate-pigmented polyvinyl butyral wash primer (as described in Plastic (March, 1953), pages 86-87), drying, and applying a thin anchor layer of the mn-methacrylamido 100 benzaldehyde polyvinyl acetal from an alcoholic solution This solution comprised 10 parts of the polymeric acetal, 0 03 part of benzoin methyl ether, 65 parts of methanol and 25 parts of n-butanol After the anchor 105 layer had dried thoroughly, the extruded film was simultaneously laminated to the base and the surface press-polished by pressing between polished plates at 100-1205 C for one minute at 300 lbs per square inch The film 110 was cooled under pressure. Such a mi methacrylamidobenzaldehyde polyvinyl acetal layer on a steel base plate was exposed in contact with a special negative containing lines of varying width, double rules, 115 lines meeting at acute

angles, dots of various sizes and reverse print areas Exposure time was 20 minutes and the surface of the transparency was placed at a distance of 8 to 10 inches from a bank of sixteen 30-watt 120 fluorescent lamps which have a phosphor showing peak emission at 3500-3600 A The exposed plate was gently brushed in a tray of methanol at 40-45 C to remove the unexposed areas The plate was then rinsed and 125 given a brief additional exposure to harden further the addition-polymerized polyvinyl acetal printing relief image This plate was locked on the cylinder of a rotary printing press and printed in normal manner The test 13 Q 786,119 786,119 was discontinued after upwards of 50,000 impressions had been made since little or no wear was evident Reproduction of the detail present in the negative was excellent. Additional accelerated wear tests using an abrasive ink and paper on plates made from this polyvinyl acetal printing relief showed that the material is approximately equivalent to copper electrotypes in wear resistance. A halftone plate from a 150-line screen negative was prepared by exposing and processing a photosensitive polyvinyl acetal layer laminated to a metal base plate as described above The plate obtained gave a printed image of excellent tonal gradation with dots 0 001 to 0 002 inch in diameter present in the extreme highlights.

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* GB786120 (A)

Description: GB786120 (A) ? 1957-11-13

Improvements in or relating to means for controlling the lateral positionsof movingwebs of material

Description of GB786120 (A)

COMPLETE SPECIFICATION Improvements in or relating to Means for Controlling the Lateral Positions of Moving Webs of Material We, sill TS-SCHUCIRERTWERKE AHTI- B-GESELLSCHAFT, a German Company, of 1 Berlin-Siemensstadt and Erlangen, STermany, 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 state- meut This invention relates to means for controlling the lateral position of a moving web of material. When a web of material is caused to move in the direction of its length the possibility exists of the edge of the web deviating from its normal position transversdy of the direction of travel. As an example of this, webs of paper which are wound on to rolls and which travel through a rotary printing press or a cutting machine or a similar device may move transversely due, for example, to irregularities in the winding. In the ease of, for example, a multi-colour rotary printing machine, the result of such a deviation is that a displaeement of the successively applied inks of different colours is prodnced, so that undesirable colour margins are formed. Tn the case of cutting machines the consequence of such a lateral deviation of the web of material would be that the sections cut off would not be right-angled. An object of the present invention is to reduce the disadvantages outlined above bv controlling and regulating the position of the edges of webs of material. According to the invention there is prorided means for controlling the lateral position of a moving web of material, for example a web of paper moving in the direction of its length in a rotary printing press, wherein one or more register marks is, or are, provided on a rotatable element which is disposed on one side of the web near the edge thereof and projects beyond such edge, there being arranged on the other side of the web a light source which directs a beam of light onto said edge and the exposed part of said element, and wherein a photo-electric device is arranged to generate impulses when the mark or marks or part thereof appear in the illuminated area, such impulses being used to control an adjustment device which operates in accordance with the nature of said impulses and serves to correct the lateral position of the web should it deviate from the desired or nominal position, the nature of the mark or marks and the proportion of said element which is exposed dictating the nature of the impulses in respect of their instants of occurrence relative to a reference impulse or in respect either of their wave form or (in the case where

there are more than one mark on said element) their frequency. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made to the accompanying drawing in which: Figs. 1 to 3 are plan views of three different means for controlling the position of a moving web of material. Referring now to the drawing, in each of Figs. 1. to 3 a web 1 of material moves in the direction of the arrow, that is to say in the direction of the length of the web. One edge of the web 1 is shown in its nominal position and is designated by 3 and it is supposed that the web may move laterally so that the edge 3 lies between an innermost extreme position 3a and an outermost position 3b. In Fig. 1 a roller 2 is disposed with its axis in a plane horizontally below that of the web 1 and perpendicular to the edge 3. The roller is provided with a register mark 4 on its circumference, the mark taking the form of a line which is inclined to the roller axis. The roller is arranged to rotate in the direction indicated by the arrow and the register mark on it is so arranged that when the edge of the web is in its nominal position part of the mark, that is the end which leads when the roller rotates, is concealed by the web of material. A light source (not shown) is provided and it projects a beam on to the edge of the material and on to part of the roller 2, thereby producing a spot of light 5 on the material and the roller. A photoelectric device (not shown) is so arranged near the web that it generates an impulse when the register mark appears in the spot of light 5. It will be readily appreciated that the instants at which the impulses commence will depend upon the proportion of the register mark which is covered by the web, the impulses commencing earlier when the edge of the web is in the position 3a than when it is in the position 3b. A reference impulse is also produced optimally, mechanically or by other means and the impulse derived from the photoelectric device is compared with this reference impulse so as to actuate an adjustment member which corrects the position of the web accordingly. The reference impulse can, for example, be produced by scanning a reference mark 6 on the roller. The mark 6 may, however, be formed on another member (not shown) coupled to the roller 6. If desired the roller 2 may be driven directly by the web of material but it is advantageous for it to be driven from a separate constant speed source since it is then possible to detect lateral movement of the edges in a manner independent of the speed of the web. In Fig. 2 a roller 7 is arranged with its asis parallel to the edge 3 of the material. The register marlr on the surface of the roller is here designated by 8, the spot of light from the light source by 9 and a reference mark

on the roller surface by 10, the latter being scanned bv a reference scanning device 10cr In this case the register mark 8 is parallel to the axis of the roller so that, as in the previous case, when the roller is driven the instants at which the impulses occur relative to the reference impulses depend upon the position of the edge of the web. A differential impulse can be derived by comparison of the impulses produced by the register mark and the reference mark and this differential impulse is arranged to cause actuation of the member which corrects the position of the web. As mentioned with reference to Fig. 1, the reference mark can be arranged on a roller or a member (not shown which is then coupled to the roller 7. Fig. 3 shows a further constructional example in which a roller 2 is arranged with its asis perpendicular to the edge 3 of t.he web. In this ease, however, the surface of the roller is provided with a plurality of register marks ila lib and lie all parallel with the axis of the roller. The register marks are of varying length, the marks 11(L being the longest and the marks lie being the shortest. One end of each register mark terminates at a circum- ferential line on the roller, this line corresponding with the extreme position 'a of the edge of the web. Thus when the edge of the web is at or near the extreme position 36b at least part of each of the marks 11a, lib and lie will be visible so that the frequency of the impulses generated by the photo-electric device will be high. On the other hand, when the edge is at or near the extreme position 3b only the marks 11a will be partly visible so that the frequency of the impulses will be low. At the correct or nominal position of the web an intermediate or reference frequenel- will he obtained. It will be appreciated that more than three different lengths of register marks can l)e employed if desired. The factual frequencies derived from the photo-electric device will also, of course, depend upon the numbers of each kind of rev sister mark present. The marks are arranged symmetrically around the circumference of the roller. When the edge of the web is in its correct position, or within a region the width of which is equal to the difference between the lengths ot the register marks 117, and lie, the reference frequency is obtained and the adjustment member is not actuated. A\rhen, however, the edge moves outside this region the frequency and the shape of the impulses alter and these alterations, with the aid of a dividing network, lead to the actuation of the adjustment member which corrects the position of the web. In this ease, as in the case illustrated by Fio. 1 the roller may be driven br the web itself or it may be independently driven at a constant speed. Instead of musing register marks of different lengths, it is possible for one or more register marks of, for example, triangular shape to be

so arranged on the periphery of tulle roller. preferably at equal intelwals, that one side of each triangle extends parallel to the edge of the weh of material. In the nominal position of the weh, half of each triangle is concealed by the web from the photo-eleetrie device. Consequenfly, there is then produced a sequence of impulses with a predetermined wave form (i.e., amplitude and duration of indi-idual impulses and the length of interval between successive impulses). The wave form of the impulses is changed with alteration of the position of the edge of the web so that the aforementioned predetermined wave form acts as a standard for the deviation of the edge from its nominal or pre-caleulated position. The evaluation of the impulses is advantageously effected by a dividing network in combination with an amplitude filter which sereens out the higher harmonics. A magnetically operated electric impulse generator mav be used in scanning the reference marks. What we claim is 1. Means for controlling the lateral position of a moving web of material, for example a web of paper moving in the direetion of its length in a rotary printing press, wherein one or more register marks is. or are, provided on a rotatable element which is disposed on one side of the web near the edge thereof and projects beyond such edge, there being arranged on the other side of the web a light source which directs a beam of light onto said edge and the exposed part of said element, and wherein a photo-electric. device is arranged to generate impulses when the mark or marks or part thereof appear in the illuminated area, such impulses being used to control an adjustment device which operates in accordance with the nature of said impulses and serves to correct the lateral position of the web should it deviate from the desired or nominal position, the nature of the mark or marks and the proportion of said element which is exposed dictating the nature of the impulses in respect of their instants of occurrence relative to a reference impulse or in respect either of their wave form or (in the case where there are more than one mark on said element) their frequency. 2. Means as claimed in Claim 1, wherein one of said register marks is provided, being formed on the curved surface of a roller the asis of rotation of which is generally perpendicular to the edge of the web of material, such register mark being inclined to said axis and being partly masked by an edge portion of the web so that the instants of commencement of the impulses generated by the photo-electric device depend upon the position of the web, the instants at which these impulses commence when the web is in the desired position being a standard for that position and deviations from the standard causing actuation of said adjustment device.

3. Means as claimed in Claim 1, wherein one of said register marks is provided, being formed on the curved surface of a roller the axis of rotation of which is generally parallel to the edge of the web of material, such register mark being generally parallel to said axis, the arrangement being such that the roller is -partly masked bv an edge portion of the web so that the instants of commencement of the impulses generated by the photo-electric device depend upon the position of the web, the instants at which these impulses commence when the web is in the desired position being a standard for that position and deviations from the standard causing actuation of said adjustment device. 4. Means as claimed in any preceding claim, wherein the photo-electric device is associated with means for generating reference impulses, the arrangement being such that any differences between the instants of occurrence of the reference impulses and the instants of occurrence of the impulses generated by the photoelectric device create differential impulses which actuate the adjustment device for the correction of the lateral position of the web. 5. Means as claimed in Claim 1, wherein a plurality of said register marks is provided, the marks being formed on the curved surface of a roller the axis of rotation of which is generally perpendicular to the edge of the web of material, such register marks being of differing lengths and being arranged symmetrically around the circumference of the roller, the arrangement being such that the number of register marks which appear in the illuminated area depends upon the position of the web of material so that the frequency of the impulses generated by the photo-electric device also depends upon the position of the web. 6. Means as claimed in Claim 1, wherein a plurality of said register marks is provided, the marks being formed on the curved surface of a roller the axis of rotation of which is generally perpendicular to the edge of t.he web of material, such register marks having a continuously variable width, for example of triangular form, and being masked from the photoelectric device by the web of material to an extent which depends upon the position of the web, so that the wave form of the generated impulses when the web is in the desired position can be employed as a standard for the deviation of the web from the desired position. 7. Means as claimed in Claim 4, wherein the reference impulses are derived from a separate scanning arrangement which is arranged to co-operate with a reference mark formed on the roller or on a rotatable member connected thereto. 8. Means as claimed in Claim 2 or 3 or any one of Claims 5 to 7, wherein the roller is driven at constant speed

* GB786121 (A)

Description: GB786121 (A) ? 1957-11-13

Wattage controller system for electric heaters

Description of GB786121 (A)

PATENT SPECIFICATION Invntar: CHARLES ROGER TURNER N 786 121 Date of Application and filing Complete Specification Oct 3, 1955. & 8 " 1 ' B No 28052/55. Complete Specification Published Nov 13, 1957. Index at Acceptance:-Classes 38 ( 4), A 2 B( 2: 3: 5); and 38 ( 5), Bl S( 1 A: 5: 11). International Classification: -HO 2 c, j. COMPLETE SPECIFICATION Wattage Controller System for Electric Heaters We, PROCTOR ELECTRIC COMPANY, a Corporation organized under the laws of the State of Pennsylvania, United States of America, of Third and Hunting Park Avenue, Philadelphia, 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: - The present invention relates to a wattage controller system for controlling an electric heating load such as an electric range surface heating unit It is a prime object of this invention to provide a control that will effect rapid energization of a heating unit until the desired operating temperature is reached, with subseqoent senergization ito maintain the heating unit at that selected temperature value. A further object is to provide a system to bring a heating unit rapidly to a selected temperature that will utilize an initial instantaneous energization rate that is greater than that required to maintain the heating unit at the maximum designed " heat " and thereafter will cyclically energize and deenergize at the high instantaneous energization rate to thereby maintain the heating unit

at its maximum " heat " after the unit has reached the predetermined temperature value. Another object is to provide a control system that utilizes a thermal wattage controller to give the various average wattage inputs to the heating unit, wherein one range of inputs is effected through a wattage input in excess of the maximum the unit could normally tolerate continuously, while utilizing, at another range of inputs, a wattage considerably less than the maximum the unit could tolerate continuously. A further object is to provide a system that will permit the economy of using a single coil heating unit. The type of thermal wattage controller contemplated is c racterized in that it provides lPicete 35 a particular wattage input or " heat " by cyclically energizing and de-energizing the heating unit In systems of this type, the thermal wattage controller should not cycle on and off too frequently The maximum number of cycles in any period of time is established at about 2 per minute This is not considered excessive from the standpoint of contact life, radio interference, etc On the other hand, in systems of this type, the length of the individual " on " plus " off " intervals should not exceed a certain maximum This is especially important in the lower range of inputs because excessive " off" intervals are synonymous with large overshoot and undershoot and inherent difficulty in maintaining correct average temperature at the unit. It is, therefore, another object to provide a controller that will permit repid energization of a single coil heating unit and will have favourable cycle lengths at the various heat levels. Briefly, the present invention contemplates the energization of a single coil electric range heating unit from a 3-wire electrical supply through a controller which, by way of example, has the following characteristics:Assuming the maximum continuous duty wattage for the heating unit at 1250, " high " heat equivalent to 1250 watts and " Medium High " heat equivalent to approximately 690 watts are obtained by cyclically energising the heating unit at an instantaneous load of 2400 watts; and the lower heats, namely: "Medium ", "Low ", and " Simmer ", are obtained by cyclically energizing the heating unit at an instantaneous load of 600 watts By using the 2400 watts energization, the heating unit is rapidly brought to its desired temperature level corresponding to the input selected. Utilizing the 600 watts energization in the lower heats, provides better cycle length characteristics and less inherent fluctuation due to overshoot and undershoot than otherwise might be expected at the lower wattage levels. Referring now to the accompanying drawing:Figure 1 is a schematic

diagram of the control system for the heating unit; Figure 2 is a detailed elevational view of a preferred form of the thermal switch, Figure 3 is an exploded view of the thermomotive unit of the switch of Figure 2; Figure 4 is a comparison chart of the cycle lengths at the various " heats " when operating at various energization levels, and Figure 5 shows in graphical form the contour of the cam used with the thermal switch. Figure 1 shows a heating unit 10 connected to a 3-wire electrical supply line 11 through a controller 12 Heating unit 10 is of the rod type generally used for electric range surface units and is made up of one continuous resistance coil so that there are only two terminal connections 14 and 15 Heating units of the rod type are well known in the art, and it will suffice to say that such unit comprises a metallic sheath 16, and inner coil resistance wire 17, held in place by a heat conducting and electrically insulating ceramic material 18 The unit rests on a spider designated as 19 and is supported on the top of an electric range through a reflector 20 and other constructional elements The supply line 11 comprises line L, and L and a neutral or common wire N In the discussion to follow the voltage between L, and L, and N will be taken nominally as 118 volts, while the voltage between L, and L. will be taken nominally as 236 volts. The controller 12 is shown to include a thermal switch 26 and a double-throw singlepole switch 27, both insulatedly supported in or on the controller 12 The thermal switch 26 is preferably of the type disclosed and claimed in U S Patent No 2,623,137, and includes the improvement thereon shown -in U S Patent Specification No 2,673,444 The thermal switch described in U S Patent Specification No 2,623,137 includes a thermomotive means having a free end and a fixed end and comprising two thermomotive members of thermomotively dissimilar material disposed in substantially parallel spaced relationship The more active of these themomotive members is a bimetallic element having its low expansion side facing the less active thermotive member, the latter being a heater strip These two thermomotive members are mechanically connected together adjacent the fixed end of the thermomotive means and at least at one point along the length of the members Thermal insulating means is disposed between the bimetallic element and the heater strip Electrical connections, including contacts cyclically operable by the free end of the thermomotive means, are provided for supplying energy to the heater strip to heat the same rapidly during each cycle, the bimetalic elements receiving heat from the heater strip through said thermal insulating means The initial heating of the heater strip causes a rapid thermomotive action in opposition to the thermomotive action of

the more active bimetallic element on heating Likewise the initial cooling of the heating strip causes a rapid movement in 70 opposition to the movement of the bimetallic element on cooling According to U S Patent Specification No 2,673,444 the above mentioned thermal insulating means is a flexible medium which provides accurate mechanical 75 spacing between the bimetallic element and the heater strip and a heat conductivity path which is substantially unchanged over a substantial range of clamping pressure provided between the bimetallic element and the heater strip 80 In addition the opposed surfaces of said medium are characterised by a multiplicity of small contact areas. In Figure 1 the bimetallic element 30 and the heater strip 31 of the thermal switch 26 85 are shown schematically, while the thermal insulating medium between these two elements is omitted The bimetallic element 30 is fixed at one end and is secured to the heater strip at its free end An electrical contact 32 is car 90 ried on the free end of bimetal 30 In Figure 1, the bimetallic element 30 is arranged to flex upward, having its low expansion side up A cooperating contact 33 is carried on an adjustable blade 34 which is biased toward cam 95 36 and is positioned thereby through a cooperating projection 34 a on blade 34 Cam 36 has an "off" position in which the projection 34 a seats in a recess of the cam, and the cam has a progressively rising surface in the 100 counter-clockwise direction as viewed in Figure 1. Figures 2 and 3 shows the preferred form of the thermal switch 26 for specific use with a heating unit of 2400 watts maximum ener 105 gization Between the bimetal 30 and the heater 31, as shown more clearly in Figure 3, are disposed a rectangular strip of metallic screening 40, an asbestos strip 41 and a mica strip 42 On the left hand side of the heater 110 31 are disposed a mica strip 43, an asbestos strip 44, and a brass shim 45 On the righthand side of bimetal 30 are disposed a brass strip 46 and a brass clamping strip 47 The entire structure is fixedly supported on the 115 switch case 12 through a rivet 48 An insulator 49 separates the base of bimetal 30 and heating element 31 As may be seen in Figure 2, one electrical connection to the thremal switch is connected to heater 31 through a terminal 120 58, while the other electrical connection is connected to resilient blade 34 which is insulated from heater 31 and from bimetal 30. The bimetal used in this particular embodiment is of the kind known under the Regis 125 tered Trade Mark " Morflex " and is 0 035 " thick; and the heater is of 80 % nickel, 20 % chrome and has an approximate resistance of 084 ohms The wire screening is of 30 x 30 mesh and of 015 " diameter stainless steel 130 786,121 786,121 3 wire, calendered to 030 " thickness The brass strips 45, 46 and 47 are each 010 " thick

The asbestos strips are of the Quinterre grade and are 005 " thick, while the mica strips are 001 " thick In normal application this wattage controller has an additional bimetal 50, shown in part in Figure 2, to compensate for changes in the ambient temperature and thereby make wattage inputs independent of any such changes. Referring again to Figure 1, the single-pole, double-throw switch 27 comprises a cantilevermounted flexible blade 52 carrying a contact 53 at its free end The switch blade 52 is biased upwardly, e g by its own resilience, and has a projection 52 a which cooperates with a cam 54, said cam having a raised profile 54 a and a lower profile 54 b When profile 54 a engages projection 52 a of blade 52, contact 53 engages a stationary contact 55 On the other hand, when profile 54 b determines the position of blade 52, contact 53 engages a stationary contatct 56 Cams 54 and 36 are controlled by manual adjusting member or knob 57 and are adapted to move simultaneously These cams, while shown as separate members, can be integrally formed in a single profile or face cam member. The connections are as follows: Blade 34 is connected to line L,, heater 31 is connected to one end 14 of the heating unit 10, blade 52 is connected to the other end 15 of the heating unit, stationary contact 55 is connected to the neutral or common line N, and contact 56 is connected to line L 2. In operation, the user turns the manual knob 57 of the controller 12 to get any one of a number of heats Cam 54 controls the connections according to the heat selected, while cam 36 controls the operation of the wattage controller according to the heat selected Usually the selectable heats will be those which have been termed in the electric range are as the " High ", "Medium High ", " Medium ", " Low " and "Simmer " heats The following table shows the wattages corresponding to these heats and also shows how the heats are obtained: I II III Average Energization Percentage wattage during "on" energization Heat watts period I I Ix 100 Watts Energized "High" 1250 2400 51 2 % "Medium high" 687 2400 28 6 % "Medium " 437 600 73 % "Low " 250 600 41 7 % "Simmer" 113 600 18 8 % The wattages given are obtained by cyclically energizing and de-energizing the heating unit 10 so that the wattages are averages over a period of time and not the energization that would result from the continuous connection of a resistance across a given voltage The " High " and " Medium High " heats are obtained by cyclically energizing and deenergizing the heating unit 10 when the controller is set to energize the heating unit across lines L, and L 2, i e, 236 volts In this condition, the wattage drawn at any instant of energization is 2400 watts The connections necessary to obtain this type of energization can be traced in Figure 1 from line L 1 through blade 34 to contacts 33 and

32, heater 31, heating unit 10, blade 52, stationary contact 56 and thence to line L, Thus to obtain the 1250 watts corresponding to the " High " heat, the table indicates that 52 1 % energization is necessary, while at the " Medium High " heat an energization of approximately 28 6 % is necessary. At the lower heats, the heating unit 10 is energized between line L, and the neutral line N The circuit is traced from line L,, blade 34, contact 33, contact 32, heater 31, heating unit 10, blade 52, stationary contact 55, thence to line N Since the voltage now being applied 85 across the heating unit is y that of the previously described energization, the wattage would be 4-, or in the example chosen, 600 watts Referring to the above table, "Medium" heat is indicated as being 73 %, 90 "Low" heat is indicated as 41 7 % and " Simmer " as 18 8 %-all at 600 watts instantaneous during an energization interval. It is to be understood that the values set forth in the above table are not limiting values 95 but are arbitrarily chosen to be commensurate with established practice and with respect to such other factors as life characteristics of the heating unit and the thermal wattage controller 100 In order to obtain operation according to the above table, the cam 54 is designed to provide the connections as set forth above for the higher and lower heats, while the cam 36 is designed to effect the adjustments of blade 34 105 which will give the time percentages of energization for the different wattages Figure 5 shows the cam throws employed in the preferred embodiment It will be seen that as 786,121 higher inputs are selected the cam 36 will produce greater initial displacement of blade 34 toward the left as viewed in Figure 2 This in turn requires that the thermomotive member 30 be operated at a higher average temperature for the cyclic energization and deenergization of contacts 32 and 33 to occur. It will be apparent that by going to the higher wattage input, the heating unit will attain its operating tempenature in a much shorter time than if the heating unit were energized from a cold start continuously at a rate corresponding to the nominal high heat value. In the aforementioned embodiment of the present invention, the time,required io attain % heat is approximately 1 2 minutes, while with continuous 1250 watt energization, approximately 3 minutes would be required to bring the heating unit to temperature. It is to be noted that the thermal wattage controller used to govern the input to the heating unit has associated therewith a predetermined thermal mass to dissipation ratio Thermal switch 26, with its associated mass-providing shims 46 and 47 provides a device that senses the previous heating history of the heating unit 10 Thus, if heating unit 10 had been previously run at its " High " heat, and then

the unit is turned on after a short lapse of time, the thermostat would permit only a short interval of energization at the 2400 watt level and thereby prevent damage to the heating unit. The thermostat would thereafter cyclically deenergize and reenergize the heating unit at 2400 watts during any "on" cycle, so as to provide an average wattage of 1250. Figure 4 shows at A the " on " times and the total cycle time intervals to attain the respective heats with the present invention The values given at B indicate the " on " and the total cycle times that would be prevalent if 2400 watts were used from the " High " input level down to the " Simmer" level It is apparent that the cycle times would become very long at the " Low " and " Simmer " levels if 2400 watts were used over the entire range. It will be noted from Figure 4, chart B that as the progressively lower " heats " are selected, the total cycle time increases, and further that the rate of increase is larger as progressively lower " heats " are chosen. Due to the inherent characteristics of the thermal wattage controller, if chart B were to be projected beyond the "High" heat, i e by designing cam 36 to give still higher heats, the cycle time would increase and become increasingly longer until a continuous energization were obtained Graphically this would result in a generally Ushaped curve of total cycle time to average wattage, with the lw point of the U near the middle wattages The portion of the U-shaped curve shown in Figure 4, chart B, represents the characteristic of a particular thermal switch having a specific current flowing through its heater during any energization period In that specific instance the current flowing is approximately 10 2 amperes corresponding to the 2400 wattage series circuit, the heating unit having an approximate resistance of 23 1 ohms When 70 the switch is operated at a lower current, i e. 5.1 amperes, by reduction of the voltage to the series circuit of the heating unit 10 and heater 31, the thermal switch provides a total cycle time curve of the same characteristic U-shape 75 The low point of the curve is likewise in the vicinity of the middle range of wattages taken on the basis that maximum wattage results in continuous energization at the afore-mentioned current level By the present invention the F O middle portion of two such curves are chosen, this composite curve being shown at A of Figure 4 In other words, by the present invention the thermal switch is caused to operate at the middle of its characteristic U-shaped curve 85 over the entire range of desired " heats ", this being accomplished by the utilization of the high and low instantaneous wattages. Figure 4 shows further that in the medium heat range the total cycle

times are substanti 90 ally equal regardless of whether 600 watts or 2400 watts are used By using the 600 watts to obtain the medium heat, there is less tendency for overshoot and undershoot because of the relatively long " on " period when compared to 95 that on use of the 2400 watts instantaneous energization Further, it will be apparent that if the switch were to be operated over long periods of time in the medium " heat ", more contact life could be expected when using 600 100 watt energization than when using the 2400 watt energization However, if the 2400 watts energization were used, the system would have the advantage of rapid heating to obtain the preselected temperature The choice of which 105 wattage to use for obtaning the medium " heat " can be seen to depend upon the arbitrary specifications that may be set up by the user or the manufacturer. It will be understood, of course, that the 110 invention contemplates such modifications and embodiments as may occur to those skilled in the art, without limitation to the specific disclosure herein: -

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* GB786122 (A)

Description: GB786122 (A) ? 1957-11-13

Method of making multi-axially stretched aircraft canopies and the like

Description of GB786122 (A)

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PATENT SPECIFICATION 786,122 Date of Application and filing Complete Specification: Oct 3, 1955. No 28128/55. Application made in United States of America on June 13, 1955. Complete Specification Published: Nov 13, 1957. index at acceptance:-Class 87 ( 2), Al R( 14 C 1 X:20:42). International Classification:-B 29 d, f. COMPLETE SPECIFICATION Method of Making Multi-axially Stretched Aircraft Canopies and the like We, GOODYEAR AIRCRAFT CORPORATION, a Corporation organized under the laws of the State of Delaware, United States of America, with offices at 1210 Massillon Road, Akron, Ohio, 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 a method of making curved aircraft enclosures from transparent plastic sheet material, such as methyl methacrylate, and, more particularly, is concerned with a method for effecting a bi-axial stretching of the sheet material before or during the formation of the canopy, the bi-axial stretching being in the neighborhood of 100 %. It is the general object of the invention to improve the physical characteristics of transparent plastic canopies for aircraft and the like-and specifically to improve the shatter resistance of such canopies by the provision of methods and apparatus for stretching the sheet material longitudinally and laterally up to 100 % prior to or during the formation of the canopy. Another object of the invention is the provision of a method whereby the transparent sheet material to be formed into a canopy is first stretched longitudinally to about twice its length and, while held in stretched condition, is then formed into a curved canopy shape, the lateral stretching of the material during the forming to the canopy being greater than normal and approaching 100 %. Another object of the invention is to control the amount of lateral stretching of the sheet material during is formation to canopy shape

by controlling the depth, i.e thickness of the jig in which the canopy is formed. lPrice 3/6 l Another object of the invention is to control the front to rear curve of the top of the canopy by controlling the size of circular pods formed integrally with the canopy at the front and rear thereof 50 Another object of the invention is to hold the sides of the transparent plastic sheet against inward movement during the longitudinal stretching of the sheet, but without interferring with the longitudinal 55 stretching thereof. For a better understanding of the invention, reference should be had to the accompanying drawings wherein Fig 1 is a plan view of a typical apparatus for carry 60 ing out the method of the invention; Fig 2 is a side elevation of the apparatus of Fig 1 but with the sliding side clamps removed to better illustrate the other features of the apparatus; 65 Fig 3 is an enlarged fragmentary sectional view taken on line III-III of Fig 1 and illustrating details of a sliding side clamp. Fig 4 is an enlarged fragmentary 70 sectional view taken substantially on line TV-IV of Fig 1 and showing the manner of effecting extra lateral stretching of the sheet material during the forming of the canopy; and 75 Fig 5 is a diagrammatic plan view of a modification of the apparatus for effecting both longitudinal and lateral stretching of the plastic sheet material prior to formation into a canopy 80 Having particular reference to Figs 1 to 4 of the drawings, the numeral 1 indicates a frame or table carrying as its top a flat metal plate 2 of rectangular shape, with the plate 2 having a conduit 3 85 connected thereto and extending therethrough to supply fluid under pressure to the upper side of the plate for forming the canopy as hereinafter described. Positioned on top of the plate 2 around 90 Fa 25 p e LS 53. 786,122 the edges thereof is a framelike flat gasket or member 4 of rubber or ru Lbber-like material against which rests the sheet 5 of transparent plastic material The sheet 5 may be of laminated or single construction The sheet 5 extends beyond the plate 2 at one end of the apparatus and is adapted to be removably secured in clamping means 6 of any suitable type mounted on brackets 7 fastened to the plate 2. The other end of the sheet 5 is releasably gripped in a jaw 9 of any suitable type and the jaw is adapted to be moved longitudinally as by a cable 9 which extends to a winch 10 driven through a gear reducer 11 and a variable speed transmission 12 by a motor 13. During thle longitudinal stretching of the sheet 5, by the mechanism last described, it is sometimes desirable to hold the sides of the sheet against inward movement but without interferring with the longitudinal stretching operation This is achieved by providing a bar

14 spaced from each side of the plate 2 but mounted thereon by brackets 15 Each bar 14 slidably carries a plurality of clamps 16 each of which is adapted to releasablv engage with the edge of the sheet 5, as best seen in Fig 3 Rollers 17 and 18 carried by each clamp engage with the bar 14 and allow the clamps to move longitudinally but not laterally of the bar. Thus, by attaching the clamps 16 in spaced relation to the sides of the sheet 5 prior to the longitudinal stretching thereof, the sides of the sheet are held against inward movement during longitudinal stretching, all without interferring with the longitudinal stretching operation. It will be understood that stretching of the sheet 5 is facilitated by heating it in an oven to a relatively soft plastic state prior to the actual stretching operation. Fig 5 illustrates diagrammatically a modification of the method and apparatus already described In Fig 5, the sheet 5 of transparent plastic material held by the fixed clamping means 6 at one end and engaged by the jaw 8 at the other is first stretched longitudinally by pull on the cable 9, in the manner heretofore set forth During this operation, in accord with the procedure of the apparatus of Fig 5, the sides of the sheet 5 are not held against inward movement and they move inwardly to the position shown in Fig 5 In other words, the clamps 16 are not utilized, in fact, they are removed from the apparatus. After the sheet 5 has been stretched longitudinally, jaw 8 is locked in stretched position, for example, by dropping pins through holes 19 in the jaw and into corresponding or selected holes in plate 2. Then a pair of jaws 20 are releasably clamped to the sides of the sheet 5, and cable 9 is detached from jaw S and connected to cables 21 which connect to jaws The cables 21 extend over pulleys 2270 mounted on laterally directed frame portions 23 Pull on cable 9, by wineh 10, and the driving means therefor now stretches sheet 5 laterally. Once the sheet a has been stretched by 75 one or other of the methods described, and while it is held in the stretched condition, but before it has had time to set, the sheet is formed to the compoundl-y curved canopy shape This is done with 80 the aid of a jig, indicated as a whole by the numeral 24 The jig 24 is normally lifted out of the way during the stretehing of the sheet a, but as soon as the stretching is completed, 85 the jig 24 is quliclkly moved into position over top of the sheet and the jig is clamped tightly over the sheet to hold it down against the gasket 4 carried on plate 2 Quick-release clamps 25 hold the 90 assembly together. Fluid, usually compressed air, is now supplied throu h conduit 3 to the under side of the sheet 5 and the sheet is blown or moved by the

differential pressure 95 existing on its opposite sides, upwardly into the jig opening The jig opening is of dumbbell-shape including pod-like, substantially circular ends 26 and 27 connected by a portion 28 forming the canopy 100 proper. The jig 24 also has gauge members 29 (shown only in Fig 2 for the sake of clarity) of inverted U-shape positioned substantially at the tonction of the circu 105 lar ends 26 and 27 with the center portion 28 The "auoe members 29 may slant somewhat away from each other as shown in Fig' 2 and define substantially the lines or planes on which the canopy is mounted 110 in its support frame in the airplane Joining the gauge members 29 and extending centrally and longitudinally of the jig is a top center line gauge member 30. In the method of the invention, the 115 sheet 5 is blown into the jig openings and out into contacting engagement with the gauges 29 but spaced approximately 1 '4 inch from the gauge member 30 Usually the sheet 5, with controlled blowing, is 120 brought out to just touch gauge members 29 to effeet a seating thereagainst but without further blowing of the canopy. The jig 24 has several important features First, as best seen in Figs 2 125 and 4, the jig is made up of a base portion 31 having a plurality of shim-like portions 32 for controllably building up the thickness of the jig Serews:33 may be used to secure any selected number of 130 786,122 the shim-like portions 32 to the base portion 31. Selecting or controlling the thickness of the jig 24 is important for the reason that, in this manner, it is possible to control the amount of lateral stretch given the sheet 5 during the canopy-forming operation More specifically, and having reference to Fig 4, when the jig 24 is relatively thick, as in Fig 4, the sheet 5 has to stretch through the jig opening, wherein it is supported, before it can move outwardly above the jig in free blown semi-circular contour It has been discovered that it is possible to take a sheet 5, which has been longitudinally stretched % by the apparatus of Figs 1, 2 and 3, and to then blow the sheet in a jig, such as that of Fig 4, and effect 100 % stretch laterally of the sheet. In other words, if the sheet 5 is initially painted with grid lines defining one inch squares, and the sheet is formed into canopy shape as last described, the grid lines on the finished canopy define two inch squares indicating 100 % longitudinal and 100 % lateral stretch in the finished canopy over the original sheet. It now becomes a relatively simple matter to control the amount of lateral stretch in the finished canopy by using more or less shim-like portions 32 in association with the jig 24, always remembering that the thicker the jig, the greater the lateral stretch.

This feature of controlling lateral stretching of the canopy by controlling the thickness of the jig is of paramount importance when the sheet is not stretched laterally when flat However, the feature may also be utilized with the apparatus and method of Fig 5, as will be understood. The second important feature of the jig 4524 is illustrated in Fig 1 which shows that the pod-like circular openings 26 and 27 are provided with a plurality of shimlike members 34 and 35 for changing the size of the circular openings Of course, as the sheet 5 moves through the openings 26 and 27, it takes the form of a portion of the surface of a sphere and near the end of the blowing operation substantially a hemisphere It has been discovered that the larger the openings 26 and 27 are made the flatter the top center line of the canopy becomes Thus it becomes possible to control the contour of the top center line of the canopy, and accordingly the front to back contour of the canopy and its streamline characteristics, by selecting the proper size openings 26 or 27, the size of these openings being changed by using more or less of the shim-like members 34 and 35 in each opening, which 65 members are removably held in position with screws or other means not sh Qwn In those regions where the shim-like portions 32 overlap the shim-like members 34 and 35, it will be understood that separable 70 shim-like portions 32 are removably mounted on and coincide to the shim-like members 34 and 35 being held in position by screws 36. In this manner the top center line of the 75 canopy can be contoured to match the requirements of a particular gauge member 30 The chain dotted lines in Fig 2 illustrate a typical shape that the sheet 5 takes at the end of a blowing operation 80 Once blown in the manner described, the canopy is allowed to cool and set, whereupon the jig 24 is unclamped and lifted and the canopy is removed from the apparatus and trimmed to finished shape 85 at gauge members 29 and an inch or two below the upper surface of the jig 24. Reference has been made to 100 % longitudinal and lateral stretch This is usually desirable to obtain good shatter resistance 90 improvement, but sometimes greater stretch is used or lesser stretch dependent upon the particular plastic sheet material.

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* GB786123 (A)

Description: GB786123 (A) ? 1957-11-13

Loop and hook fastening device

Description of GB786123 (A)

PATENT SPECIFICATION Date of Application and filing Complete Specification: Oct 4, 1955. 786,123 No 28289155, 2) 19 Application made in United States of America on March 28, 1955. Complete Specification Published: Nov 13, 1957. Index at acceptance:-Classes 43, Q 3, and 89 ( 3), F 2, J 2 81. International Classification:-A 44 b, B 25 c. COMPLETE SPECIFICATION Loop and Hook Fastening Device I, LAWRENCE STEINMETZ, a Citizen of the United States of America, of 165 East 19th Street, Brooklyn, New York, United States of America, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:This invention relates to devices for setting either loops or hooks of garment fastening buckles into the waistband fabric of trousers, skirts or the like. Metallic loops and hooks 'forming a buckle assembly for trouser waistbands or the like have been used for many years A recent improvement in the use of such loops and hooks has been the provision of a backing plate disposed on the opposite side of the fabric from either the loop or hook to provide a reinforcement and extended clinching surface when the prongs of the loop or hook are clinched backward against the backing plate and fabric. It is a principal object of the present invention to provide an improved device for fastening selectively either loops or hooks together with their associated backing plates to a garment without substitution or adjustment of the device. Another object of the invention is to provide an improved punch jaw member adapted to correctly position selectively either a loop or a hook element relative to an anvil, the punch jaw member requiring no change or adjustment to position either the loop or hook element.

Yet another object of the invention is to provide an improved anvil adapted to receive and correctly position relative to common anvil elements a backing plate for either a loop or hook fastener member. Further objects, features and the attending advantages of the invention will be apparent with reference to the following lPrice 3/61 specification and drawings in which: - Fig 1 is a perspective view of a fastener loop element together with the punch jaw member and anvil as shown in inverted positions, with the anvil above the punch jaw 50 member instead of in the normal position with the anvil in the lower position, Fig 2 is a Longitudinal section of the punch jaw member and anvil with a fastener loop element driven through a fabric and 55 about to be fastened to the backing plate as positioned on the anvil; Fig 3 is a view similar to Fig 2 but with the parts in the position at the moment of fastening the loop and backing plate to 60 the fabric; Fig 4 is an elevational view of the anvil together with a backing plate to be positioned thereon, Fig 5 is a top view of the punch jaw 65 member device with a loop element positioned thereon; Fig 6 is a longitudinal sectional view taken on the line 6-6 of Fig 2, Fig 7 is a sectional view similar to Fig 6 70 but with a fastener hook and associated backing plate in position instead of the fastener loop and associated backing plate shown in Figs 2 and 6; Fig 8 is a top plan view of the punch 75 jaw member with the fastener hook in position; Fig 9 is a perspective view of the fastener hook shown in Figs 7 and 8, Fig 10 is a top plan view of the anvil with,80 the backing plate for a fastener hook positioned thereon; Fig 11 is a view similar to Fig 10 but with a backing plate for a fastener loop positioned thereon; and 85 Fig 12 is an exploded perspective view of the punch jaw member. Referring to the drawings, it should be pointed out that the relative positions of the anvil and the punch jaw member have been 90 d 2 Z 1 786,123 inverted in Figs 1 to 3, 6 and 7, as the anvil is normally stationarily positioned below the punch jaw member which is movable towards the anvil Both the anvil and the punch jaw member of the invention are intended to be mounted in a suitable handoperated riveting machine although the invention may be equally well adapted for use with power-operated machinery as should be obvious to those skilled in the art. The fastener loop 10 which is to be secured by apparatus according to the invention is shown in Figs 1, 2, 3, 5 and 6 of the drawings The fastener hook 11 which also may be secured by the same apparatus without change is shown in Figs 7, 8 and 9 of the drawings The associated backing plate 12 for the fastener loop 10 is shown in Figs. 2, 4, 6 and 11 of the drawings and the associated backing plate 13 for the fastener hook 11 is shown in Figs 7 and 10 of the drawings.

The punch jaw member as shown in Fig. 12 is comprised of a body portion 15 having a rounded shank end 16 for removably securing the punch jaw member to the movable punch or head of a riveting machine (not shown) The other end of the body portion 15 is provided with a pair of oppositely disposed guide portions 17 and 18 for receiving, guiding and longitudinally positioning the side end portions 19 and 20 of the fastener loop 10 as shown in Figs 1 and 5 of the drawings A side plate 21 having a side guiding element 22 is secured to the body 15 by means of the bolt 23 and nut member 24 to be received within the aperture 25 of the body member 15 The inner walls 26 and 27 constitute a second pair of oppositely disposed guide members for receiving, guiding and longitudinally positioning the side end portions 28, 29 of the fastener hook 11 as shown in Figs 7, 8 and 9 of the drawings The same previously described side guiding element 22 is adapted to be received in the notch 32 of the fastener hook 11 (Fig 8) for laterally positioning the hook on the punch jaw member and the same side guide element 22 also functions to engage a side portion of the loop 10 (Fig 6) for laterally positioning the hook on the punch jaw member when desired A permanent magnet 33 may be placed within the aperture 25 and is supported on the nut 24 for purposes of temporarily holding in position a fastener loop or hook during the setting operation, it being assumed that either the fastener loop or hook is formed of magnetic material. Either the fastener loop 10 or fastener hook 11 is provided with prong portions as shown to be driven through a garment fabric and suitable apertures of an associated backing plate 12 or 13 respectively In order to upset the prong portions against the backing plate and thereby secure the fastener loop or hook to the garment, an anvil is provided as shown most clearly in Fig 4 of the drawings The anvil is provided with a body portion 40 having a shank adapted to be 70 removably secured to the stationary base of a suitable riveting machine (not shown) It will be noted that the backing plate 12 for the loop fastener 10 is of less width than the backing plate 13 for the hook fastener 75 11 Accordingly, the anvil 40 is provided with a first set of recessed guiding portions 42, 43, 44, 45, 46 and 47 (Fig 1) for positioning the loop backing plate 12 relative to the anvil elements 49 and 50 as shown in 80 Figs 4 and 11 of the drawings A second set of recessed guiding portions 52, 53 54, 55, 56 and 57 (Fig 10) are additionally provided for also positioning the hook backing plate 13 relative to the same anvil cle-85 ments 49 and 50. The use of the punch jaw member and anvil should be obvious from the foregoing description and drawings Either a fastener loop or hook is positioned -on the punch 90 jaw member body 15 (Figs 1 and 8) and an associated backing plate for the respective loop (Fig 11) or hook (Fig

10) fastener is positioned on the anvil 40 Thereafter a garment fabric is placed over the anvil and 95 the punch jaw member moved towards the anvil so that the prongs of the respective loop or hook are caused to penetrate the fabric and the apertures of the backing plate to contact the upsetting anvil elements 49100 and 50 whereby the prongs will be bent back against the backing plate to clinch the fabric. It should be noted that the loop fastener 10 is supported on suitably arranged shoulder portions 60, 61 of the seating body 15 (Fig 2) 105 while the hook fastener 11 is supported on the surface 62 of the body 15 and the surface 63 of the nut 24 (Figs 7 and 12) during the driving of the respective loop or hook in the process of being secured to the backing 110 plate and garment. Various modifications may be made within the scope of the appended claims.

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