SILICONE RUBBER COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a composition capable of giving a silicone rubber excellent in heat resistance, and excellent in shelf stability in a compound stage by incorporating a specific amount of cerium oxide powder having a specified specific surface area and a specified pH value. SOLUTION: Cerium oxide powder having a specific surface area by the BET method of at least 80 m2 and a pH value of a 3 wt.% aqueous dispersion of 2.0-5.5 is incorporated in an amount of 0.05-10 wt.%. This composition preferably comprises 100 pts.wt. of an alkenyl group-containing diorganopolysiloxane desirably having at least two alkenyl groups bonded to an Si atom in one molecule; 0.1-10 pts.wt. of cerium oxide powder having a specific surface area by the BET method of at least 80 m2 and a pH value of a 3 wt.% aqueous dispersion of 2.0-5.5; 5-150 pts.wt. of a reinforcing filler (e.g. dry method silica); and a curing agent in an amount enough to cure the composition. Preferably, the curing agent is an organic peroxide. This composition is useful for rubber parts used around an automobile engine and the like.