Rubber-modified styrene resin composition

A rubber-modified styrene resin composition comprising 99.9 to 97 percent by weight of a rubber-modified styrene resin (E) and 0.1 to 3 percent by weight of a polyorganosiloxane-containing graft copolymer (D), the polyorganosiloxane-containing graft copolymer (D) being one selected from the group consisting of a copolymer (a-1) and a copolymer (a-2), the copolymer (a-1) and the copolymer (a-2) being prepared with a polyorganosiloxane (A) produced by polymerizing 99.9 to 99.6 percent by weight of an organosiloxane with 0.1 to 0.4 percent by weight of a graft-linking agent;

• the copolymer (a-1) being prepared by polymerizing 0.01 to 5 parts by weight of a monomer (B) comprising 100 to 50 percent by weight of a polyfunctional monomer (b-1) having at least two intermolecular polymerizable unsaturated bonds and 0 to 50 percent by weight of another copolymerizable monomer (b-2) in the presence of 86 to 94.99 parts by weight of the polyorganosiloxane (A), and then polymerizing the resulting polymer with 5 to 13.99 parts by weight of a vinyl monomer (C), wherein the sum of the compounds (A), (B), and (C) is 100 parts by weight;
• the copolymer (a-2) being prepared by polymerizing 27.5 to 14 parts by weight of a vinyl monomer (C) in the presence of not less than 72.5 and less than 86 parts by weight of the polyorganosiloxane (A), wherein the sum of the compounds (A) and (C) is 100 parts by weight.