SILICA-CONTAINING SILICONE RESIN COMPOSITION AND ITS MOLDED PRODUCT

摘要

This invention provides a silica-containing silicone resin composition which can impart high heat resistance, high transparency, and high dimensional stability and is suitable, for example, for optical applications such as lenses, optical disks, optical fibers, and flat panel display substrates, and window materials for automobiles. This silica-containing silicone resin composition is produced by incorporating 1 to 70% by weight of silica fine particles into a silicone resin composition prepared by mixing a silicone resin, which is represented by [RSiO<SUB>3/2</SUB>]<SUB>n</SUB> wherein R represents an (meth)acryloyl-containing organic functional group; and n is 8, 10 or 12, and is composed mainly of polyorganosilsesquioxane having a basket structure in its structural units, and an unsaturated compound, which contains in its molecule at least one unsaturated group represented by -R<SUP>3</SUP>-CR<SUP>4</SUP>=CH<SUB>2</SUB> or -CR<SUP>4</SUP>=CH<SUB>2</SUB> wherein R<SUP>3</SUP> represents an alkylene group, an alkylidene group, or group -OCO-; and R<SUP>4</SUP> represents hydrogen or an alkyl group, and is radically copolymerizable with the silicone resin at a weight ratio of 1 : 99 to 99 : 1.