PREPARATION OF SILICONE RUBBER COMPOSITION AND SILICONE RUBBER MOLDED PART

摘要

PROBLEM TO BE SOLVED: To provide a silicone rubber composition which greatly decreases the dispersion of mechanical properties caused by voids in silicone rubber molded parts or the frequency of spark outs in coating electric wires. SOLUTION: This composition comprises (A) 100 pts.wt. organopolysiloxane raw rubber of the formula: Ra SiO(4-a)/2 (wherein R is a substituted or unsubstituted monovalent hydrocarbon group; and a is a number of from 1.8 to 2.3), (B) from 10 to 100 pts.wt. fine powdery silica and (C) from 0.05 to 10 pts.wt. methyl group-substituted benzoyl peroxide having a maximum particle size of 50μm or smaller and an average particle size of 20μm.