Patent ID: 7582697

Claim:
A silicone rubber adhesive film comprising a composition formed from (A) 100 weight parts organopolysiloxane gum that has at least two alkenyl groups in each molecule; (B) 30 to 150 weight parts wet-method hydrophobic reinforcing silica that has a specific surface area of at least 200 m 2 /g and that comprises SiO 4/2 units and siloxane units selected from the group consisting of the R 1 3 SiO 1/2 unit, R 1 2 SiO 2/2 unit, and R 1 SiO 3/2 unit (R 1 in these formulas is C 1-10 hydrocarbyl or C 1-10 halogen-substituted hydrocarbyl), in which the molar ratio of the non-SiO 4/2 siloxane units to the SiO 4/2 units is 0.08 to 2.0; (C) 0.1 to 10 weight parts organohydrogenpolysiloxane that contains at least two silicon-bonded hydrogen atoms in each molecule; (D) a reaction mixture from (a) organopolysiloxane that has a branched molecular chain structure and that contains at least one silicon-bonded alkenyl group in each molecule and at least one silicon-bonded hydrolyzable group in each molecule, said organopolysiloxane having the general formula (R 2 R 3 2 SiO l/2 ) a (R 3 3 SiO l/2 ) b (R 3 O l/2 ) c (SiO 4/2 ) d in which R 2 is C 2-12 alkenyl, each R 3 independently represents a C 1-10 monovalent hydrocarbon group excluding alkenyl groups, a and c are numbers greater than or equal to one, b is a number greater than or equal to zero, d is a number greater than or equal to three but less than thirty, (a+b)/c=0.2 to 2, and (a+b+c)/d=0.4 to 4, and (b) a silicon-containing compound that contains at least one silicon-bonded epoxy-functional hydrocarbon group and at least one silicon-bonded hydrolyzable group, said silicon-containing compound having the formula R 4 R 3 n Si(OR 3 ) 3-n in which R 3 is a C 1-10 monovalent hydrocarbon group excluding alkenyl groups, R 4 is a glycidoxy-functional or epoxycyclohexyl-functional hydrocarbon group, and n is one or zero, wherein component (D) is incorporated in said composition in a quantity such that the weight ratio of component (D) with respect to component (A) does not exceed 1/5; and (E) curing accelerator in an amount sufficient to cure the composition comprising components (A) to (D).