Abstract: A rubber-modified styrene type polymer comprising from 1 to 15 parts by weight of a dispersed phase made of a rubber-like elastic material and from 99 to 85 parts by weight of a continuous phase made of a polymer comprising from 35 to 75 wt % of styrene type monomer units and from 65 to 25 wt % of (meth)acrylate type monomer units, wherein the rubber-like elastic material is a styrene (30 to 50 wt %)-butadiene (70 to 50 wt %) block copolymer, the weight average molecular weight (Mw) of the polystyrene portions of this block copolymer is from 45,000 to 75,000, and the ratio (Mw/Mn) of Mw to the number-average molecular weight (Mn) is from 1.20 to 1.80.

Abstract: A rubber-modified styrene type polymer excellent in transparency and excellent in impact strength and moldability, is presented.

Abstract: A rubber-modified styrene type polymer excellent in transparency and excellent in impact strength and moldability, is presented. A rubber-modified styrene type polymer comprising from 1 to 15 parts by weight of a dispersed phase made of a rubber-like elastic material and from 99 to 85 parts by weight of a continuous phase made of a polymer comprising from 35 to 75 wt % of styrene type monomer units and from 65 to 25 wt % of (meth)acrylate type monomer units, wherein the rubber-like elastic material is a styrene (30 to 50 wt %)-butadiene (70 to 50 wt %) block copolymer, the weight average molecular weight (Mw) of the polystyrene portions of this block copolymer is from 45,000 to 75,000, and the ratio (Mw/Mn) of MW to the number-average molecular weight (Mn) is from 1.20 to 1.80.

Abstract: A rubber-modified styrene type polymer excellent in transparency and excellent in impact strength and moldability, is presented.A rubber-modified styrene type polymer comprising from 1 to 15 parts by weight of a dispersed phase made of a rubber-like elastic material and from 99 to 85 parts by weight of a continuous phase made of a polymer comprising from 35 to 75 wt % of styrene type monomer units and from 65 to 25 wt % of (meth)acrylate type monomer units, wherein the rubber-like elastic material is a styrene (30 to 50 wt %)-butadiene (70 to 50 wt %) block copolymer, the weight average molecular weight (Mw) of the polystyrene portions of this block copolymer is from 45,000 to 75,000, and the ratio (Mw/Mn) of Mw to the number-average molecular weight (Mn) is from 1.20 to 1.80.

Abstract: A method for producing a molded heat-resistant resin product, which comprises injection-molding a thermoplastic resin (A) and a rubber-reinforced heat-resistant resin (B) having a high temperature side glass transition temperature, the difference of which from the high temperature side glass transition temperature of said thermoplastic resin (A) is within 60.degree. C., simultaneously as they are.

Abstract: A process for producing a maleimide-modified heat-resistant ABS resin comprising a maleimide copolymer, an ABS graft copolymer and an AS copolymer, which comprises kneading a maleimide copolymer, an ABS graft copolymer and optionally an AS copolymer to obtain a heat-resistant master batch resin, and further kneading an ABS graft copolymer and an AS copolymer to the heat-resistant master batch resin or kneading a resin composed of an ABS graft copolymer and an AS copolymer, to the heat-resistant master batch resin.

Abstract: A thermoplastic resin composition well balanced among heat resistance, high-impact properties and moldability is provided, which composition comprises 50 to 90 parts by weight of a random copolymer (A) composed mainly of .alpha.-methylstyrene units and acrylonitrile units, 0.2 to 1.0 part by weight based on 100 parts by weight of the random copolymer (A), of an oligomer (B) composed mainly of .alpha.-methylstyrene units and acrylonitrile units and having a molecular weight of 200 to 500 and 10 to 50 parts by weight of a dienic rubber-aromatic vinyl monomer-vinyl cyanide graft copolymer (C).