Curable silicone compositions comprising liquid resin and uses thereof

Claim 1

A composition comprising (I) a liquid copolymeric organopolysiloxane, prepared by a method comprising (A) forming a homogeneous mixture having an acid number greater than zero and comprising (a) an organic solvent solution of a resinous copolymeric siloxane containing silicon-bonded hydroxyl radicals and consisting essentially of R 3 SiO 1/2 siloxane units and SiO 4/2 siloxane units wherein the ratio of the number of said R 3 SiO 1/2 siloxane units to the number of said SiO 4/2 siloxane units has a value of from 0.6/1 to 0.9/1 and each R denotes, independently, a monovalent hydrocarbon radical and (b) a liquid organohydrogenpolysiloxane wherein each organic radical is, independently, a monovalent hydrocarbon radical, there being an average of at least one silicon-bonded hydrogen radical per molecule of said organohydrogenpolysiloxane, and (B) heating said homogeneous mixture to remove substantially all of said organic solvent therefrom and (II) a polydiorganosiloxane having the formula ZR'".sub.2 SiO(R'".sub.2 SiO).sub.c SiR'".sub.2 Z wherein Z denotes hydroxyl or R'" and each R'" denotes independently, a monovalent hydrocarbon radical, there being an average of at least two vinyl radicals or silicon-bonded hydroxyl radicals per molecule and c has a value sufficient to provide a viscosity of from 0.1 to 10,000 Pa·s at 25° C. for the polydiorganosiloxane.