RUBBER-MODIFIED STYRENE BASED RESIN COMPOSITION HAVING IMPROVED ABRASION RESISTANCE

PURPOSE:A styrene based resin composition, obtained by incorporating a specific polyorganosiloxane in a polymer prepared by copolymerizing a monovinyl aromatic comound with a specific rubber-like material, and having improved abrasion resistance and surface activity. CONSTITUTION:A styrene based resin composition obtained by incorporating (A) 100pts.wt. rubber-modified resin composition prepared by dissolving 15-3wt% rubber-like material, containing >=80wt% high-cis polybutadiene (containing >=90mol% cis-1,4 bonds), and having 1-2.5mum average particle diameter in 85- 97wt% monovinyl aromatic compound, and polymerizing the resultant mixture with (B) 0.25-1.25pts.wt., expressed in terms of Si, polyorganosiloxane, expressed by formula I (R is monofunctional organic grops, e.g. alkyl; R' and R'' are phenyl or 1-6C alkyl; m is a number to keep the polyorganosiloxane in a liquid state at ordinary temperature), and having 100-30,000 stokes viscosity at 25 deg.C.