Silicone composition, method for the preparation thereof and silicone elastomer

摘要

A silicone composition comprising (A) 100 parts by weight of a polydiorganosiloxane containing an average of at least two silicon-bonded alkenyl groups per molecule; (B) 75 to 150 parts by weight of an organopolysiloxane resin having a number-average molecular weight of from 2,000 to 5,000 and comprising R<3>2R<4>SiO1/2 units and SiO4/2 units wherein each R<3> is independently selected from monovalent hydrocarbon and monovalent halogenated hydrocarbon groups free of aliphatic unsaturation, R<4> is selected from R<3> and alkenyl, the mole ratio of R<3>2R<4>SiO1/2 units to SiO4/2 units is from 0.6:1 to 1.1:1, and the resin contains an average of from 2.5 to 7.5 mole percent of alkenyl groups; (C) an organohydrogenpolysiloxane having an average of at least three silicon-bonded hydrogen atoms per molecule in an amount to provide from one to three silicon-bonded hydrogen atoms per alkenyl group in components (A) and (B) combined; (D) an adhesion promoter in an amount to effect adhesion of the composition to a substrate; and (E) a hydrosilylation catalyst in an amount to cure the composition.