| 摘要 |
A cross-linkable or cross-linked silicone compsn. contains: (a) a polyorganosiloxane, and (b) a polyvinyl alcohol (PVA1) with ester index (EI) at least 80 (120-200) and dynamic viscosity below 12 mPa.s (below 10 mPa.s), with the proviso that PVA1 is mixed with another PVA if the polyorganosiloxane fraction includes at least one polydiorganosiloxane with at each end of the chain at least two condensible or hydrolysable gps., or a single OH gp., with the molecules of the polydiorganosiloxane(s) being able to react together and/or with an organosilane cross-linking agent carrying at least 3 condensible or hydrolysable gps. if the polydiorganosiloxane is terminally hydroxylated and/or of the polyhydrogen siloxane type, in presence of: (c) a catalyst system contg. a catalyst of the Sn gp., with the mechanism being polycondensation. |
