Silicone rubber adhesive film

1. 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).

2. The silicone rubber adhesive film of claim 1 , in which the silicon-containing compound (b) of component (D) is independently selected from the group consisting of gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropylmethyldimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, and 3,4-epoxycyclohexylethylmethyldimethoxysilane.

3. The silicone rubber adhesive film according to claim 1 , that characteristically has a Williams plasticity of 300 to 800 in its uncured state and a green strength of 0.1 to 0.5 MPa.

4. The silicone rubber adhesive film according to claim 1 , that has a heating loss when heat-cured for 30 minutes in a 130° C. oven of not more than 0.25 weight %.