Abstract: Provided is a thermoplastic resin composition having excellent weather resistance, impact resistance, and fluidity and also excellent color developing properties and residence heat stability. A graft copolymer (A) prepared by graft polymerization of a certain amount of a specific monomer (a2)onto a certain amount of composite rubber (a1) composed of a conjugated diene rubber polymer and a cross-linked acrylic ester polymer. The tetrahydrofuran-soluble portion of the composite rubber (a1) has a weight-average molecular weight of 50000 or more in terms of polystyrene and a degree of swelling in toluene of 7.0 or more, or in the composite rubber contained in the graft copolymer, the number of particles having an equivalent-circle diameter of 150 nm or less is 50% or less of the total number of the composite rubber particles.

Abstract: A rubber-reinforced styrene type resin composition for resin foams, the resin foams having a specific gravity of 0.3 to 0.7 and a ratio of the thickness of a skin layer to the thickness of the resin foam of 0.3 to 20%; the composition comprising: 10 to 99% by weight of a rubber-reinforced styrene type resin (A) which is obtained by bulk polymerization of a rubber polymer and an aromatic vinyl monomer, a vinyl cyanide monomer, and if necessary, another monomer that is copolymerizable with these monomers, a weight average particle diameter of the rubber polymer being 0.7 to 3 ?m, and 1 to 90% by weight of a copolymer (B) which is obtained by copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer, and if necessary, another monomer that is copolymerizable with these monomers (with the total of the rubber-reinforced styrene type resin (A) and the copolymer (B) being 100% by weight).

Abstract: Provided is a thermoplastic resin composition having excellent weather resistance, impact resistance, and fluidity and also excellent color developing properties and residence heat stability. A graft copolymer (A) prepared by graft polymerization of a certain amount of a specific monomer (a2) onto a certain amount of composite rubber (a1) composed of a conjugated diene rubber polymer and a cross-linked acrylic ester polymer. The tetrahydrofuran-soluble portion of the composite rubber (a1) has a weight-average molecular weight of 50000 or more in terms of polystyrene and a degree of swelling in toluene of 7.0 or more, or in the composite rubber contained in the graft copolymer, the number of particles having an equivalent-circle diameter of 150 nm or less is 50% or less of the total number of the composite rubber particles.