| 摘要 |
<p>1305979 Laminates RHONE-POULENC SA 26 May 1970 [27 May 1969] 25326/70 Heading B5N A reinforced sheet substantially free from micro holes having a total thickness of 120- 350 Á consists of an organopolysiloxane elastomer film supported by a mesh material which is a woven, knitted or netted fabric, partially penetrating one of the faces of the film, the film being produced from a composition vulcanizable at ambient temperature under the influence of liquid or vaporous water and comprising anα,#-dihydroxy diorgano polysiloxane oil and, as cross-linking agent, an organo silane, polysilane or polysiloxane containing more than two hydrolysable groups per molecule. The reinforced sheet may be produced by forming a film of the vulcanizable composition on a non- adherent temporary support, e.g. a film of polytetrafluoroethylene or polyethylene or paraffin-coated paper which may be slightly roughened, exposing this film to liquid or vaporous water until the composition is partially vulcanized but the surface still tacky, applying the mesh material to the film under a pressure of 0À05-0À3 bar and exposing the resulting reinforced sheet to liquid or vaporous water until vulcanization is complete. The reinforced sheet may subsequently be separated from the temporary support. A film of elastomer representing 30-80% of the thickness of the organopoly-siloxane part of the final sheet may be formed on the temporary support, exposed to moisture to effect at least partial vulcanization and one or more further layers of the vulcanizable composition applied and partially vulcanized before applying the mesh material. The mesh material may be made from cotton, polyhexamethylene adipamide polycaprolactam, polyethylene terephthalate or polyacrylonitrile fibres. The hydrolysable silane cross-linking agent may be an organotrialkoxysilane, organotriacyloxysilane, organotriamino silane, organotriaminoxysilane or organotrisiminoxy-silane. The vulcanizable composition may also contain not more than 40% by weight of a filler having a maximum particle diameter of 0À1 Á, e.g. silica which may have been treated with an organopolysiloxane, a pigment and a diorganopolysiloxane of which the chain ends are blocked by trimethyl silyl groups which acts as a plasticizer. The reinforced sheets may be used in gas exchangers, e.g. in artificial lungs, or to cover burns.</p> |
