Clear Silicone Coated Fabric

European Patent Office (21) Publication number: 0 220 804 Office europeen des brevets A1

cunurcMix rA I tlM | APPLICATION

Ky "ppiiuaiion numDer: ob3UbZi4.7

5) Priority: 20.09.85 US 778461 © Applicant: DOW CORNING CORPORATION 2) Date of of publication application: Midland Michigan 48640(US) 06.05.87 Bulletin 87/19 © Inventor: Gutek, Beth Irene *)~v _ . Designated Contracting States: 9791 djC8 Road BE DE FR GB Freeland Michigan(US) Inventor: Vanwert, Bernard 5305 Fox Hill Drive Norcross Georgia(US)

® Representative: Lewin, John Harvey et al Elkington and Fife High Holborn House 52/54 High Holborn London WC1V 6SH(GB)

v_z . unuiuu ui una imvbmuun produces a silicone coated glass fabric which is translucent or transparent as desired and which has a smooth dry surface. The coated glass fabric is useful in producing air- supported and tension-supported roofs for structures such as greenhouses. A glass fabric is first coated with a polydiorganosiloxane, in which the organo radicals are methyl and phenyl radicals in a ratio of from 0.25 to 3.7, in an amount sufficient to impregnate the fibers in the yarns of the fabric, but leaving tthe interstices of the fabric open. This first layer is •then followed by coating with a polydimethylsiloxane * elastomer to give a continuous layer, then coating 'with an elastoplastic organopolysiloxane resin to give » a smooth, dry surface on the glass fabric reinforced I sheet.

@ I 1 0 220 804 2

CLEAR SIUCONE COATED FABRIC

This invention relates to fabric coated with 0.25 and 3.7 which is subsequently coated with a polyorganosiloxanes which is useful as architectural layer of polydimethyisiloxane elastomer and a layer fabric for use in structures such as air-supported of elastoplastic organopolysiloxane resin. and tension-supported roofs. Fig. 2 is a cross-section of the fabric coated In U.S. Patent Number 3,373,053, issued s as in Fig. 1 showing the first coat of silicone March 12, 1968, Clark teaches a transparent sheet elastomer which impregnates and coats the fabric material consisting essentially of square woven yarn while the second coat of polydimethyisiloxane glass cloth coated and impregnated with a cured elastomer covers the first coat and fills in the polymethylphenylsiloxane having from 45 to 55 interstices of the fabric between the yarns. percent by weight phenyl groups. This transparent 70 The invention relates to a silicone coated glass sheet was useful in electrostatic printing equipment fabric comprising a transparent or translucent sili- to produce transparencies. cone coated glass fabric comprising a first layer of In United States Patent Number 4,489,127, is- polydiorganosiioxane in which the organo radicals sued December 18, 1984, Gutek and VanWert are methyl and phenyl radicals in a ratio of from teach a method of producing a silicone resin-coat- 75 0.25 to 3.7, impregnating and coating the yarns of ed fabric comprising an elastoplastic or- the glass fabric but not filling in the interstices of ganopolysiloxane resin coated silicone elastomer the glass fabric; a second layer of silicone membrane reinforced with fabric. The coated fabric elastomer covering the first layer and filling in the is useful in producing structures such as air-sup- interstices of the glass fabric; and a third layer of ported roofs or tension-supported roofs. 20 elastoplastic organopolysiloxane resin to give a The fabric of Gutek et al. has proven useful in smooth, dry surface. making structures which do not require a large This invention relates to a method of producing amount of light on the interior. A comparable fabric a transparent or translucent silicone coated glass which was clear or transparent to sunlight was fabric comprising (A) applying to a glass fabric a needed for uses such as in greenhouses or solar 25 first layer consisting essentially of a polydior- heated structures. ganosiioxane in which the organo radicals are This invention relates to a silicone elastomer methyl and phenyl radicals in a ratio of from 025 coated glass fabric which is translucent or transpar- to 3.7 in sufficient amount to impregnate and coat ent. A first coating is applied to the glass fabric the yarns of the glass fabric, but not filling the reinforcement, which coating consists essentially of 30 interstices of the glass fabric, then (B) applying a polydiorganosiioxane in which the organo radicals second layer consisting essentially of a silicone are methyl and phenyl radicals in a ratio of from elastomer in sufficient amount to cover the first 0.25 to 3.7. A sufficient amount of this first coating layer and to fill in the interstices of the glass fabric, is applied to the glass fabric to completely coat then (C) applying a third layer consisting essen- and impregnate the fibers in the threads of the 35 tially of an elastoplastic organopolysiloxane resin, fabric, but not enough to fill in the interstices of the to yield a transparent or translucent sheet having a fabric. This first coating is then followed by a glass fiber reinforcement and a smooth, dry sur- coating of polydimethyisiloxane elastomer to fill in face. the interstices, which elastomer coating is in turn In the development of coated fabric useful for coated with an elastoplastic organopolysiloxane 40 structural uses such as air-supported or tension- resin to give a clear or translucent glass reinforced supported roofs, an improved coated fabric was sheet having a slick, dry surface. developed which first coated the fabric with silicone It is an object of this invention to produce a elastomer to coat the yarns in the fabric, then silicone resin-coated glass fabric which is clear or overcoated the cured elastomer with a thin layer of translucent which is useful in air-supported struc- 45 resin, the improvement being a method of obtain- tures or tension-supported structures. ing adhesion between the different coats on the It is an object of this invention to produce a fabric so that the coated fabric could be useful silicone resin-coated glass fabric useful in air-sup- when adhesively bonded to other surfaces, includ- ported structures or tension-supported structures ing two pieces of the coated fabric being bonded to that is clear or translucent and also economical. so each other to produce larger pieces. This coated Fig. 1 is a cross-section of a glass fabric fabric was successful in applications in which an coated with a first coat of silicone elastomer having opaque sheet was satisfactory, but not where a methyl and phenyl radicals in a ratio of between clear or translucent covering was desired, such as in a greenhouse or solar heating device.

2 4

— . — .. w..»w @ ui iu II I WOUIUI iy euiuw inw coanng to penetrate the yams and dis- silicone coated glass fabric, clear being or translu- place the air between the glass fibers. The viscos- cent, was developed to provide a clear or translu- ity of the polydiorganosiioxane can be adjusted by cent covering that could be used in structural ap- dissolving the polymer in solvent if necessary to plications with a minimum increase in cost over the 5 give the required low viscosity. A viscosity of about current method. 0.5 Pas at 258C has been found sufficiently low to Fig. 1 is a cross-section of a silicone coated impregnate the yarns and still give a coating on the glass fabric produced by the method of this inven- outside of the yarns without filling the interstices tion. The 11 of yarns are glass fibers which have between the yarns. been formed into yarns, woven into a fabric, and w After the layer 12 is applied and any solvent is then heat-cleaned to remove the oils and lubricants removed and the coating is cured, a second layer applied to the fibers in the of process forming the of silicone elastomer 21 is applied. The second irams and weaving the fabric. The fabric may be layer 21 is applied in sufficient amount to coat the reated after heat-cleaning with finish a that is com- first layer and to close the interstices of the fabric aatible with the coating to be applied over the 5 to give a continuous coating over the fabric. Prefer- jlass fabric. The fabric yarns 1 1 are coated with a ably, this coating 21 is applied in one step, for irst coat 12 of polydiorganosiioxane in which the economical reasons, but more than one application >rgano radicals are methyl and radicals phenyl in a could be used if desired. The silicone elastomer atio of from 0.25 to 3.7. The polydiorganosiioxane used for layer 21 preferably has a durometer after Mating 12 is present in sufficient amount to im- 0 curing of less than 30 on the Shore A scale. The >regnate the yarn 11 and form a around coating silicone elastomer used for layer 21 preferably is a he individual yarns. There is not sufficient coating polydimethyisiloxane elastomer because these >resent to fill in the interstices of the fabric. Be- dimethyl elastomers are the most economical and ause the polydiorganosiioxane of 12 coating con- the refractive index of layer 21 is not required to be ains both methyl and phenyl radicals, the refrac- 5 matched to the glass fabric so the more expensive ive index of the coating is closer to that of the phenyl radicals are not necessary in this layer. llass fiber than is the previously used poly- After coating 21 is applied and cured, coating 13 of limethylsiloxane. A which coating gives a visibly elastoplastic organopolysiloxane is nproved applied over degree of translucency is provided when coating 21 and cured. ufficient phenyl radical is present to give a methyl 3 Fig. 2 illustrates a cross-section of the con- J phenyl ratio of from 0.25 to 3.7 when compared struction described above and illustrated in Fig. 1. ) a coating having only methyl radicals. As the The first layer 12 is shown impregnating and coat- mount of phenyl radicals is increased, the refrac- ing the glass yarns 1 1 going in both directions as ve index of the coating increases and becomes in a woven fabric. The layer 12 does not fill the loser to that of the glass fabric. A preferred ratio > interstices between the yarns. The second layer 21 f methyl to phenyl radicals is from 0.6 to 1.5 with is shown coating the layer 12 and filling in the le most preferred ratio being about 1 to 1. The interstices between the coated yarns. jfractive index of the glass in the fabric is about As mentioned above, any of the layers of poly- .549. A polydiorganosiioxane having a 1 to 1 ratio siloxane can be composed of a single layer or of f methyl to phenyl radicals has a refractive index 1 multiple layers. Preferred is a single application to F about 1.551. A polydimethyisiloxane has a re- form each layer because this is most economical, active index of about 1.404. The closer the refrac- but multiple applications can be used to /e index of the produce coating is to the refractive index of each layer if desired. e glass fiber, the clearer the coated sheet will be. As discussed above, layer 12, forming the first this invention, it has been discovered that only coat of polydiorganosiioxane over the glass yams, e coating in direct contact with the fibers glass is is required to have both methyl and phenyl radicals quired to have the necessary match in refractive to adjust the refractive index of the coat to the dex. When the glass yarns are impregnated and desired value. As phenyl radical is added, the >ated with a polydiorganosiioxane having a refrac- refractive index value rises to approach that of the 'e index approaching that of the glass fibers and glass, but the cost also rises. The balance between is coating is subsequently coated with succeed- increased transparency of the silicone coated glass 3 coats of po'ymethylsiloxane, a finished sheet fabric and the increased cost must be determined in be produced which can be varied from translu- by the user. Polydiorganosiioxane 12 could be a mt to clear. The closer the match in refractive fluid, if it has a high enough viscosity to prevent it dex between the first coat and the glass, the from being mixed with coating 21 when it is ap- jarer the final sheet of coated glass fabric. The plied. Preferably, polydiorganosiioxane 12 is a cur- ilydiorganosiloxane used to produce the coating able polymer which forms an elastomer upon cure. : has to have a viscosity which is low to enough Any of the well-known means of making polydior- 5 0 220 804 6 ganosiloxane which cures can be useful; such as, The method of applying the various layers to the addition of organic peroxides, the use of vinyl the glass fabric can be by any of the well-known radicals in the polymer and peroxides to crosslink coating methods for silicone elastomers and sili- the polymer through the vinyl groups, the use of cone, resins. A preferred method of coating the vinyl radicals in the polydiorganosiioxane and the 5 silicone elastomer layers is by passing the fabric, addition of crosslinking agents such as siloxanes or previously coated fabric, through a bath of the containing hydrogen on silicon units in conjunction catalyzed elastomer dispersed in solvent to give with platinum containing catalyst, and the use of the desired coating thickness, then heating to drive any of the well-known methods of producing sili- off the solvent and aid in curing the elastomer cone elastomer which cure upon exposure to mois- 10 coating. In those cases in which the elastomer is ture, such as adding an alkyltrialkoxysilane to a cured by exposure to moisture, the hot air should polydiorganosiioxane having hydroxyl endblocking. contain moisture, preferably by injection of steam The second coat of silicone elastomer 21 which into the oven to aid in cure of the elastomer. The covers the first coat and fills in the interstices of silicone elastomer layer can be applied in one, two, the fabric is preferably the silicone elastomer of js or more layers. The outer layer of elastomer, at United States Patent Number 4,489,127, issued least, if it contains ingredients (i), (ii), and (iii) may December 18, 1984, which describes the preferred be tacky when it comes from the curing oven, curable silicone elastomer composition and its before it is coated with the elastoplastic or- method of manufacture. ganopolysiloxane resin. If so, the surface of the The elastoplastic organopolysiloxane resin 13 20 coated fabric is covered with a release sheet so which serves to form a smooth, dirt resistant sur- that the fabric can be rolled up for storage. To face for the coated fabric can be any of the well- continue the method, the release sheet is removed, known elastoplastic organopolysiloxane resins such and the elastoplastic organopolysiloxane resin is as these containing silicone block copolymers such coated over the silicone elastomer and cured. The as those described in United States Patent No. 25 cure times and temperatures are dependent upon 3,280,214, issued October 18, 1966 to Mitchell, such variables as coating thickness, choice of sol- United States Patent No. 3,328,481 , issued to Vin- vent if used, temperature used, and air humidity for cent; United States Patent No. 3,629,228, issued those systems curing on exposure to moisture. December 21, 1971 to Hartlein and Olsen; and Times in the range of 5 to 15 minutes at tempera- United States Patent No. 3,639,155, issued Feb- 30 tures of from 80° to 130°C have been found use- ruary 1, 1972 to Hartlein and Vincent, said patents ful. show the block copolymers and their method of The various embodiments of the method of this manufacture. invention yield a silicone resin coated glass fabric The most preferred silicone elastomer 12 and which is transparent or translucent and is useful for elastoplastic organopolysiloxane resin 13 are those 35 constructing structures such as air-supported and disclosed in United States Patent No. 4,489,127, tension-supported roofs for structures such as where the combination of silicone elastomer and greenhouses and solar heated buildings. The com- elastoplastic organopolysiloxane resin form on in- position of the first coat of polydiorganosiioxane terface which is an adhesive bond derived from a can be varied to obtain the desired degree of combination comprising (i), polydiorganosiioxane of 40 clarity in the silicone coated glass fabric. the formula X(R,SiO) aSiR2Y where R is a mon- Following are examples illustrating the method ovalent hydrocarbon radical containing no more and compositions of this invention and the silicone than 6 carbon atoms, X is a condensable endbloc- coated glass fabric that is produced and its prop- king group and a has a value such that the poly- erties. These examples are included for illustrative diorganosiioxane has a viscosity of greater than 1 45 purposes and should not be construed as limiting Pas at 25°C, (ii) a hydroxyl radical containing, the invention which is properly set forth in the solid, benzene soluble resin copolymer consisting appended claims. essentially of R3SiOi/2 units and SiO*2 units where All parts are by weight. R is as defined above, there being from 0.6 to 0.9 inclusive R3Si01/2 units for every SiO^ unit, at 50 least 95 percent of all R radicals in (ii) being Example 1 methyl, and (iii) a condensation catalyst for (i) and - (ii). These ingredients that form the interface which A glass fiber fabric was coated in accordance is an adhesive bond can be present as ingredients with this invention to produce a clear, smooth sur- in the silicone elastomer coating 12 or can be in a 55 faced, semi-flexible coated fabric. primer coat applied over the silicone elastomer A mixture of 50 parts of toluene, 50 parts of coat 12 and upon which the elastoplastic or- polyphenylmethylsiloxane fluid having a viscosity ganopolysiloxane resin 13 is applied. of about 0.5 Pa s at 25°C and about 4.5 percent

4 a

mo unru coanng solution was applied by dip- kers (methyl to phenyl ratio of and 0.5 1), parts of ping the previously coated fabric into the solution, aluminum acetyl acetonate was applied to heat then removing the solvent by heating for 10 min- cleaned glass fabric (Style 7544 from Burlington utes at 100°C. This third solution gave a thin Industries, a 0.61 kg/mJ, 7.5 x 7.5 ends per 25 mm 5 coating of about 0.04 mm to provide a bond be- construction) by dipping. The solvent was removed tween the second and fourth coats. by heating the coated fabric for 5 minutes at 100°C A fourth coating solution was prepared by mix- in a hot air oven. The coating was sufficient to ing 55 parts of an organopolysiloxane block impregnate the glass fibers and threads of the copolymer mixture, and 45 parts of toluene. The fabric, removing the air between the fibers, but not w arganopolysiioxane block copolymer mixture con- sufficient to fill in the interstices of the woven tained about 76 parts of copolymer containing 26.4 fabric. The coating was cured for 10 minutes at nol percent phenylsiloxy units, 60.5 mol percent 225°C to transform the fluid into a solvent insoluble jimethylsiloxy units, and 13.1 mol percent methyl- jolymer. The glass fibers not visible in were the nethoxysiloxy units, 3.5 parts of methyltrimethox- mating. 75 /silane, and 0.41 part of tetrabutyltitanate. The coated fabric was then dipped into 50 a The fourth coating was applied by dipping and »rcent solids solution of a low viscosity flowable, hen curing for 10 minutes at 100°C. »cetoxy cured, room temperature curing sealant, The resulting coated fabric was a clear sheet, rhe sealant was the product obtained by 90 mixing laving a slick, dry surface. The coated fabric was >arts of a hydroxyl endblocked polydimethylsilox- 20 .emi-flexible in that it could be folded back upon me fluid having a viscosity of about 13.5 Pas at tself and creased without failing by cracking. The >5°C, 1.8 parts of a hydroxyl endblocked poly- :oatings were firmly bonded to each other. limethylsiloxane fluid having a viscosity of about I.04 Pas at 25 °C, and 8.9 parts of fumed silica laving a surface area of about 150 m7g. After 2s tiorough mixing, the reinforced fluid was mixed nth 5.3 parts of a mixture of 100 parts of a 50/50 A comparative example was prepared. nixture of methyltriacetoxysilane and ethyl- A sample of glass fabric as in Example 1 was iacetoxysiiane with 0.5 part of dibutyltindiacetate. Dated with a solution of 50 parts of toluene and 50 Tie solvent was removed from this coating by 30 arts of a trimethylsiloxy endblocked polymethyl- eating for 10 minutes at 100°C. This second rtenylsiloxane fluid having a viscosity of about 0.5 oating was applied in an amount sufficient to fill in a s at 25 °C, by dipping and then drying 10 ie interstices of the fabric so that the coated fabric linutes at 100°C. The coated fabric was then 'as now completely coated with a smooth continu- pped into a second coating and dried as in Ex- us coat over the fabric. A clear sheet resulted 35 nple 1. The result was a cloudy coated sheet 'hich did not show the individual threads. glass scause the first coat of phenylmethyl fluid in this A third coating solution was prepared by mix- ise was not cured and it blended with the second ig 20 parts of a silicone mixture, 0.5 of part )at during the dipping operation so that the ma- minopropyltriethoxysilane, and 80 parts of toluene, rial in between the glass fibers of the threads no he silicone mixture consisted of the ob- product 40 nger had a refractive index close enough to that lined by mixing 27.4 parts of a hydroxyl endbloc- the glass to result in a clear coating. In the first sd polydimethyisiloxane fluid having a viscosity of :ample, the phenylmethylsiloxane first coating Dout 2 Pas at 25 "C with 29.7 of parts a solid as cured so that its refractive index was close to anzene soluble resin copolymer consisting essen- at of the glass fibers it was illy of surrounding and trimethylsiloxy units and Si02 units in a 45 ipregnating. itio of about 0.77 to 1. The resin had a hydroxyl intent of about 2.8 percent by weight. The sili- )ne mixture also contained 6.3 parts of resin >polymer obtained by treating the above type of sin copolymer with hexamethyldisilazane to re- 50 A mixture was prepared of 50 parts of toluene, ove hydroxyl radicals and replace them with parts of the polyphenylmethylsiloxane of Exam- methyisilyl radicals, 2.3 parts of isopropanol, a > 1, and 0.5 part of zinc octoate solution (8 tal of 34.2 parts of xylene, and 0.14 of part a rcent by weight zinc). The mixture was heated to action product of 115 parts of tetramethylguan- lux and water trapped off until about 1/2 of the ne, 144 parts of 2-ethylhexanoic acid, and 1036 55 ino! groups were condensed. After cooling, suffi- irts of xylene. The silicone mixture contained 43.3 nt of a mixture of ethyltriacetoxysiiane and ircent polydimethyisiloxane fluid and 56.7 percent ithyltriacetoxysilane was added to react with the sin on a solids basis. naining hydroxyl radicals. 3 9 220 804 10

A sample of glass fabric as in Example 1 was slear and flexible with a slick surface. dipped into the above mixture, then dried and cured as in Example 1. This coated fabric was clear. The second, third, and fourth coatings were Example 6 then applied as in Example 1. The finished sheet 5 was a clear sheet having a slick dry surface. Be- A first mixture was prepared by mixing 100 cause the first coat was cured, it did not blend with parts of a copolymer of the formula the second coat as in Example 2. ViMe2SiO(Ph2SiOMMe2SiO)«iSiMe2Vi w Example 4 (refractive index is 1.49) (methyl to phenyl ratio is 3.76) where the radicals are as shown in Example A mixture of 100 parts of the polyphenyl- 5, 100 parts of toluene, 0.84 part of PhSi- methylsiloxane of Example 1 was mixed with 0.9 (OSiMe2H)3, 0.15 part of the platinum catalyst of part of potassium hydroxide, then heated to 150±C ?5 Example 5, and 0.02 part of methylbutynol. and the resulting water was trapped off. Polymer- This first coating was applied to a piece of ization was continued until the viscosity was raised cloth as in Example 5, then a second, third, and to 0.7 cps, then the fluid was neutralized with fourth coating was applied as in Example 5. glacial acetic acid and filtered. The fluid was then The resulting sheet was flexible, but not as dissolved in toluene (40 parts fluid and 60 parts 20 clear as that of Example 5. It was clearer than a toluene). sheet produced as in Example 1 of Unites States A curable composition was prepared by mixing Patent No. 4,489,127 when the first coat was a sufficient solution from above to give 100 parts of polydimethyisiloxane as used in the second coat of the polyphenylmethylsiloxane with 28.3 parts of a Example 1 of this invention. 50/50 mixture of methyltriacetoxysilane and ethyl- 25 triacetoxysilane. A piece of the glass fabric of Ex- ample 1 was dipped in the above mixture and then Claims dried as in Example 1. The fluid impregnated the glass fibers of the threads and resulted in clear 1 . A transparent or translucent silicone coated threads. The impregnated sheet was then coated 30 glass fabric comprising a first layer of polydior- with a second, third, and fourth coating as in Exam- ganosiioxane, in which organo radicals are methyl ple 1 . The result was a clear, flexible sheet having and phenyl radicals in a ratio of from 0.25 to 3.7, a slick surface. impregnating and coating the yarns of the glass fabric but not filling in the interstices of the glass 35 fabric; a second layer of silicone elastomer cover- Example 5 ing the first layer and filling in the interstices of the glass fabric; and a third layer of elastoplastic or- A first coating mixture was obtained by mixing ganopolysiloxane resin to give a smooth, dry sur- 100 parts of a polyphenylmethylsiloxane having the face. formula 40 2. The silicone coated glass fabric of claim 1 in which the polydiorganosiioxane forming the first ViMe2SiO(PhMeSiO)«SiMe2Vi layer is an elastomer. 3. The silicone coated glass fabric of claim 1 in when Vi is vinyl radical, Me is methyl radical and which the polydiorganosiioxane forming the first Ph is phenyl radical, (refractive index is 1.56), 100 45 layer has a methyl to phenyl ratio of from 0.6 to parts of toluene, 4.3 parts of PhSi(OSiMe2H)3, 1 1.5. part of HMe2SiOSiPh2OSiMe2H, 0.15 part of a plati- 4. The silicone coated glass fabric of claim 3 in num catalyst having about 0.7 weight percent plati- which the polydiorganosiioxane forming the first num, and 0.02 part of methyl butynol cure inhibitor. layer is an elastomer. The mixture had a viscosity below 0.01 Pas at so 5. The silicone coated glass fabric of claim 4 in 100°C. which the second layer of silicone elastomer and A piece of the glass fabric of Example 1 was the third layer of elastoplastic organopolysiloxane dipped in the above mixture then dried and cured resin form an interface which is an adhesive bond by heating for 10 minutes at 150°C. The individual derived from a combination comprising fibers of the cloth were coated with the cured 55 (i) polydiorganosiioxane of the formula X- polymer, but the interstices of the threads were still (R2SiO)aSiR2Y where R is a monovalent hydrocar- open. A second, third, and fourth coating were then bon radical containing no more than 6 carbon applied as in Example 1. The resulting sheet was

6 Yd

/ . i no mwmoa or aaim b in which the polydior- a has a value such that the polydiorganosiioxane ganosiioxane of (A) is an elastomer. has a viscosity of greater than 1 Pas at 25°C, 8. The method of claim 7 in which the polydior- (ii) a hydroxyl radical containing, solid, ben- ganosiioxane of (A) has a zene soluble methyl to phenyl ratio of resin copolymer consisting essentially 5 from 0.6 to 1.5. of R3Si01/2units and SiO^ units where R is as 9. The method of claim 8 in which the silicone defined above, there being from 0.6 to 0.9 inclusive elastomer of (B) and the elastoplastic or- RsSiOia units for every SiO^ unit, at least 95 ganopolysiloxane resin of (C) form an interface percent of all R radicals in (ii) being methyl, and which is an adhesive bond derived from (iii) a condensation a com- catalyst for (i) and (ii). '0 bination comprising 6. A method of producing a transparent or (i) polydiorganosiioxane of the formula X- translucent silicone coated glass fabric comprising (RsSiO)aSiRjY where R is a monovalent hydrocar- (A) applying to a glass fabric a first layer bon radical containing no more than 6 carbon insisting essentially of a polydiorganosiioxane in X atoms, is a condensable endblocking group and which the organo radicals are methyl and phenyl 5 a has a value such that the polydiorganosiioxane adicals in a ratio of from 0.25 to 3.7 in sufficient has a viscosity of greater than 1 Pas at 25°C, anount to impregnate and coat the of the yams (ii) a hydroxyl radical containing, solid, ben- jlass fabric, but not filling the interstices of the zene soluble resin copolymer consisting essentially jlass fabric, then of R3SiO 1/2units and SiO** units where R is as (B) applying a second layer consisting es- o defined above, there being from 0.6 to 0.9 inclusive sentially of a silicone elastomer in sufficient amount R3Si01/2 units for every SiO^ unit, at least 95 o cover the first layer and to fill in the interstices of percent of all R radicals in (ii) being tie glass fabric, then methyl, and (iii) a condensation catalyst for (i) and (ii). (C) applying a third layer consisting essen- ally of an elastoplastic organopolysiloxane resin, 5 3 yield a transparent or translucent sheet having a liass fiber reinforcement and a smooth, dry sur- ace. 0 220 804 J) Office . application numoer

EP 86306214.7

of relevant passages wl-aooii-IwA I IUN THE r to claim APPLICATION (Int. CI.4)

3 did fl 7/00 * Column 1, lines 4-9; column 3 32 B 25/20 1, line 50 - column 2, line 15; fig. 2 * 3: 32 3 27/12 3 32 B 17/04 " — 3 32 B 17/10 — — — \ u J. Xj1)UIj£i ^ - f o * Claims * » 32 B 31/00 08 L 83/04 03 C 25/02 J0HP0RATI0N) » D * Claims *

* Totality; especially column 1, lines 30-64 * cunwoAL 1-ltLOS EARCHED (Int. CM)

•id a 03 C 25/00' 08 L 83/00

u™ u' completion or me search Examiner VIENNA | 30-12-1986 0NDER CATEGORY OF CITPn nori iucmtc ~7~ 7~ ! ~ @ - ' — K" unuorijring ine invention particularly relevant if earlier patent document, but published on or taken alone after the filing date particularly relevant if combined with another document document of the same category cited in the application technological background document cited for other reasons non-written disclosure intermediate document document — f-""" » i- ""respona.ng