Liquid copolymeric organopolysiloxanes comprising Si02 and method therefor.

摘要

Copolymeric organopolysiloxanes comprising SiO2 are prepared by forming an acidic, homogeneous mixture of a silanol-containing resinous copolymeric siloxane comprising R3SiO1/2 siloxane units and SiO2 siloxane units, an organohydrogenpolysiloxane and an organic solvent and heating the resulting mixture to remove substantially all of the organic solvent. The copolymeric organosiloxanes contain silicon-bonded hydroxyl radicals and/or silicon-bonded hydrogen radicals in varying amounts which depends upon the acidity of the homogeneous mixture that is formed and the ratio of silicon-bonded hydrogen radicals to silicon-bonded hydroxyl radicals therein. The copolymeric organopolysiloxanes are useful as a reactive component in various types of curable silicone compositions.