Abstract: A rubber-modified styrenic resin composition comprising (A) 100 wt. parts of a rubber-modified styrenic resin which contains 10 to 35 wt. % of soft component particles having an average particle size of 0.1 to 0.5 &mgr;m, where said soft component particles have a single occlusion structure comprising a core part which consists of a single continuous phase of a styrenic resin and a shell part which comprises a rubber polymer and occludes said core part, and (B) 0.1 to 10 wt. parts of a polymer having a solubility parameter (SP) of 8.45 to 8.70 and having no aromatic vinyl compound unit therein. This composition has excellent plane impact strength and gloss properties, as well as moldability and other physical properties, and satisfies properties required for exterior materials, wrapping materials and molded foam articles.

Abstract: A rubber-modified styrenic resin composition comprising (A) 100 wt. parts of a rubber-modified styrenic resin which contains 10 to 35 wt. % of soft component particles having an average particle size of 0.1 to 0.5 .mu.m, where said soft component particles have a single occlusion structure comprising a core part which consists of a single continuous phase of a styrenic resin and a shell part which comprises a rubber polymer and occludes said core part, and (B) 0.1 to 10 wt. parts of a polymer having a solubility parameter (SP) of 8.45 to 8.70 and having no aromatic vinyl compound unit therein. This composition has excellent plane impact strength and gloss properties as well as moldability and other physical properties, and satisfies properties required for exterior materials, wrapping materials and molded foam articles.

Abstract: A rubber-modified styrenic resin composition comprising 100 parts by weight of a rubber-modified styrenic resin (A) having 10 to 40% by weight of the content of a soft component particle and a mean particle diameter of the said particle of 0.1 to 1.2 .mu.m, and 1 to 30 parts by weight of fine particles having a mean particle diameter of 0.1 to 5 .mu.m and not having a glass transition temperature between -130 to 90.degree. C.A rubber-modified styrenic resin composition having superior plane impact strength, rigidity and gloss, and its molded article are provided.

Abstract: A styrene base random copolymer having a weight average molecular weight of 200,000 to 1,000,000, a monovinylbenzene unit and a divinylbenzene unit in an amount of 50 to 500 ppm by weight based on the weight of the monovinylbenzene unit, the divinylbenzene unit consisting of p-divinylbenzene unit and m-divinylbenzene unit, wherein the weight ratio between the p-divinylbenzene unit and the m-divinylbenzene unit is in the range of 100:0 to 75:25, which is superior in impact strength, melt tension, heat resistance and fluidity, and which is capable of being molded within a short molding cycle, is industrially advantageously produced by a continuous bulk polymerization without troubles such as undesirable deposits of polymeric gel material on reactor walls.

Abstract: A styrene resin composition is disclosed which constitutes 45 to 92% by weight of a styrene resin (A), 5 to 45% by weight of an olefin resin other than an ethylene-unsaturated carboxylic acid ester copolymer(B), and 3 to 25% by weight of an ethylene-unsaturated carboxylic acid ester copolymer (C). The styrene resin composition of the present invention may be used to make a variety of shaped articles which exhibit excellent mechanical properties, such as an impact strength, elongation at break and resistance against chemicals such as Freon and oil.

Abstract: Disclosed are a styrene copolymer having a weight average molecular weight of about 200,000 to 2,000,000, having 1 to 20 branching points in the Z-average molecular weight, and having a methyl ethyl ketone/methanol mixture-insoluble matter content of not more than 5% by weight and a methanol-soluble matter content of not more than 5% by weight; processes for preparing the styrene copolymer; a polystyrene resin composition containing the styrene copolymer; and injection-molded article prepared by injection-molding the polystyrene resin composition.

Abstract: Disclosed are a styrenic resin composition comprising (a) a styrenic resin having a weight average molecular weight of 100,000 to 2,000,000 and (b) a finely divided particulate inorganic or organic substance, the inorganic substance having a refractive index of 1.5-2.0 and an average particle diameter of 0.1-20 .mu.m, and the organic substance having a refractive index of 1.5-2.0 and an average particle diameter of 0.1-20 .mu.m and not having a glass transition temperature in a temperature range of 90.degree. C. or below, said particulate inorganic or organic substance accounting for 0.002 to 1 weight % based on the styrenic resin composition, as well as an injection-molded article prepared by molding the styrenic resin composition, and an extrusion-molded article comprising the styrenic resin composition in an amount of at least 50 weight %.

Abstract: Disclosed are a rubber-modified polystyrene resin composition which comprises a polystyrene resin serving as a matrix and soft component particles as dispersed therein, the composition fulfilling the following requirements (a) to (d):(a) the polystyrene resin as the matrix satisfies the following requirements:150,000.ltoreq.Mw.ltoreq.500,000wherein Mw is the weight average molecular weight, and2.ltoreq.Bn(Mz).ltoreq.20wherein Bn(Mz) is the branch count or the number of branching points in the Z-average molecular weight (Mz),(b) the soft component particles in the composition have an average particle diameter (Dp) of 0.1 to 10 .mu.m,(c) the soft component particles in the composition have a swelling index in the range of 3 to 30, and(d) the proportion of the soft component particles in the composition is in the range of 5 to 30% by weight, as well as an injection-molded article formed from the composition.

Abstract: Disclosed are a rubber-modified polystyrene resin composition which comprises a polystyrene resin serving as a matrix and soft component particles as dispersed therein, the composition fulfilling the following requirements (a) to (d):(a) the polystyrene resin as the matrix satisfies the following requirements:150,000.ltoreq.Mw.ltoreq.500,000wherein Mw is the weight average molecular weight, and2.ltoreq.Bn(Mz).ltoreq.20wherein Bn(Mz) is the branch count or the number of branching points in the Z-average molecular weight (Mz),(b) the soft component particles in the composition have an average particle diameter (Dp) of 0.1 to 10 .mu.m,(c) the soft component particles in the composition have a swelling index in the range of 3 to 30, and(d) the proportion of the soft component particles in the composition is in the range of 5 to 30% by weight, as well as an injection-molded article formed from the composition.

Abstract: Disclosed are a styrene copolymer having a weight average molecular weight of about 200,000 to 2,000,000, having 1 to 20 branching points in the Z-average molecular weight, and having a methyl ethyl ketone/methanol mixture-insoluble matter content of not more than 5% by weight and a methanol-soluble matter content of not more than 5% by weight; processes for preparing the styrene copolymer; a polystyrene resin composition containing the styrene copolymer; and injection-molded article prepared by injection-molding the polystyrene resin composition.

Abstract: A rubber modified styrene based resin composition which is excellent in the balance of impact strength and shapes appearance such as gloss and especially image clarity, and has a wide applicability in the field of housings for household electric apparatuses and the like requiring such a shapes appearance as having been difficult to achieve with conventional rubber modified polystyrenes (HIPSs), and which comprises a styrene based resin forming a matrix and particulate soft component containing rubbery elastomer dispersed in the matrix, wherein the soft component dispersed in the composition consists of a small-sized particulate component having a core/shell structure and an average particle size of 0.1 to 0.4 .mu.m and a large-sized particulate component having a cell structure and an average particle size of 0.8 to 2.0 .mu.m, a ratio by weight of the small-sized component to the large-sized component being in the range of 90:10 to 99:1, and the resin composition contains an amount of 0.01 to 0.