Styrene-based resin composition

Abstract

A styrene-based resin composition comprising (A) a styrene-based polymer and (B) a rubber-like polymer dispersed in the styrene-based polymer. The dispersed particles of the rubber-like polymer comprise a styrene-butadiene-based block copolymer comprising 5 to 95% by weight of a conventional diblock-type polymer and 95 to 5% by weight of a tapered block-type polymer, wherein the butadiene unit content of the styrene-butadiene-based block copolymer is 6 to 16% by weight, based on the weight of the composition. The particles have a weight ratio of gel content to rubber-like polymer of 1.1:1 to 4.0:1 and have a swelling index of 5 to 20. The particles have an area average diameter of 0.1 to 0.9 .mu.m, with a ratio of area particle diameter to number average particle diameter of 1.0 to 1.8. The styrene-based resin composition has a high Izod impact strength and a high drop-weight impact strength, and further has excellent gloss and stiffness properties.

Dependencies are inferred from the claim text.