Silicone defoamer composition.

摘要

Silicone defoamer compositions are prepared by heating a mixture of components which include a trimethylsiloxy-terminated dimethylpolysiloxane, a vinyldimethylsiloxy-terminated dimethylpolysiloxane, a dimethylsiloxane-methylhydrogensiloxane copolymer, (D) a trimethylsiloxysilicate, microparticulate silica, and a catalytic quantity of a platinum catalyst. The compositions of this invention are characterized by an excellent defoaming persistence and do not suffer from a deterioration in defoaming performance even under severe conditions such as vigorous agitation or alkaline conditions.