Patent ID: 8907006
Filing Date: 2014-12-09
Classification: C08G,C08K,Y10T

Abstract:
1. A process for the preparation of liquid silicone rubber base polymer compositions, comprising a) admixing fumed silica with a silazane and a protic substance in the substantial absence of an organopolysiloxane bearing aliphatically unsaturated groups, and removing ammonia to form an at least partially reacted product; b) immediately following step a), mixing at least one organopolysiloxane (i) bearing at least one aliphatically unsaturated group with said at least partially reacted product from step (a), heating the mixture thus obtained to a temperature above 80° C. and removing further ammonia and removing water to form a hydrophobic filler-containing intermediate product; and c) adding further organopolysiloxane (ii) bearing at least one aliphatically unsaturated group to said hydrophobic filler-containing intermediate product, and cooling to form a liquid silicone rubber base polymer composition, wherein at least a portion of organopolysiloxane (i) or organopolysiloxane (ii) bears at least two aliphatically unsaturated groups, wherein steps a), b), and c) all take place within one reactor.