Silicone pressure-sensitive adhesive composition

Claim 1

A silicone pressure-sensitive adhesive composition comprising (A) 30 to 70 parts by weight of a polydiorganosiloxane having the general formula wherein R denotes a monovalent hydrocarbon group, R' denotes an alkenyl group, and n is an integer having an average value sufficient to provide a viscosity of at least 500,000 centipoise at 25°C for the polydiorganosiloxane, (B) 70 to 30 parts by weight of an organopolysiloxane constituted of R" 3 SiO 1/2 units and Si0 2 units in a molar ratio of the former units to the latter units of from 0.6:1 to 0.9:1, wherein R" denotes a group selected from among alkyl groups, alkenyl groups, and the hydroxyl group, at least 95 percent of all R" groups being the methyl group, (C) an amount of an organohydrogenpolysiloxane having an average of at least 2 silicon-bonded hydrogen atoms in each molecule, said amount being sufficient to provide from 1 to 20 silicon-bonded hydrogen atoms per alkenyl group in component (A), (D) a platinum-containing catalyst for the addition reaction of silicon-bonded alkenyl groups with ·silicon-bonded hydrogen atoms, in an amount sufficient to provide from 0.1 to 1000 parts by weight of platinum for every one million parts by weight of the combined quantity of components (A) through (C), and (E) from 25 to 400 parts by weight of an organic solvent for Components (A) through (C).