METHOD FOR PREPARING ORGANOPOLYSILOXANE EMULSION COMPOSITION

摘要

An organopolysiloxane emulsion composition having good age stability is prepared by (I) emulsifying a mixture comprising (A) an organopolysiloxane of formula: HO(R 1 2 SiO) n H, (B) a surfactant and (C-1) water to form a first emulsion composition and (II) effecting emulsion polymerization of the first emulsion composition in the presence of (D) an acid catalyst below 40°C. The target emulsion composition contains an organopolysiloxane product having a viscosity ‰¥ 300,000 mPa·s at 25°C and an octamethylcyclotetrasiloxane content ‰¤ 3,000 ppm, and has an emulsified particle size ‰¤ 500 nm.