| 摘要 |
PURPOSE:To obtain the subject composition having long pot-life before molding, easily releasable from mold in molding and moldable without leaving unvulcanized part at the periphery of burr by compounding an organopolysiloxane, fine silica powder, an organo-hydrogen polysiloxane and a spherical fine particle catalyst. CONSTITUTION:The objective composition is produced by compounding (A) 100 pts. wt. of an organopolysiloxane containing at least two alkenyl groups bonded to silicon atom in one molecule and expressed by an average compositional formula RaSiO(4-a)/2 (R is univalent hydrocarbon group; (a) is 1.8-2.3), (B) 10-100 pts. wt. of fine silica powder, (C) 0.1-10 pts. wt. of an organo- hydrogen polysiloxane containing at least two hydrogen atoms bonded to silicon atom in one molecule and (D) a spherical fine particle catalyst consisting of a silicone resin containing >=0.01% (in terms of platinum metal atom) of a platinum-based catalyst (the silicone resin has a softening point of 50-250 deg.C and a particle diameter of 0.01-10mum). |
