Sumitomo Chemical Company, Limited

Hayato Kihara

Shuji Yoshimi

Takahiro Ishii

Satoshi Nakagawa

Masayuki Fujita

Shinichi Mitsui

Hiroshi Miyagi

Takeshi Fujii

Tatsuya Miyatake

Nobuo Oi

Yasuro Suzuki

Kenji Atarashi

Takashi Anbo

Hiroto Mukaiyama

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.

Rubber-modified styrenic resin composition and molded article thereof

A shrink film comprising a non-crystalline copolymer of ethylene with an alkenyl aromatic hydrocarbon, and having a transparency, a low temperature shrinking property, a high shrinkage ratio and a small natural shrinkage.

Shrink film

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.

Rubber-modified styrenci resin composition and molded article thereof

There is provided a rubber-modified styrenic resin composition comprising a rubber-modified styrenic resin containing soft component particles of a salami structure and a polymer having a predetermined solubility parameter, which is much more improved in both of plane impact resistance and Izod impact resistance, while retaining a high level of other properties such as rigidity, gloss and moldability.

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.

Rubber-modified styrenic resin composition and its molded article

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.

Styrene base random copolymer and process for producing the same

A styrene base polymer superior and well-balanced in mechanical strength and fluidity and also superior in heat resistance is industrially advantageously produced by a radical polymerization process comprising;

Process for producing styrene base polymer

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.

Styrene resin composition and shaped article thereof

There is provided a process for producing a styrenic polymer having a weight average molecular weight (Mw) of 200,000-500,000, a number average molecular weight (Mn) of 100,000-450,000 and a molecular weight distribution (Mw/Mn) of from 1.1 to 2 by free radical polymerization. There is also provided a styrenic polymer, a styrenic resin composition comprising such polymer and a molded article comprising such composition. Said styrenic polymer and said resin composition have excellent flowability during molding and also excellent mechanical strength.

Process for producing styrenic polymer

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.

Styrene copolymers, polystyrene compositions, and injection-molded

The method for controlling a polymerization rate, in a continuous radical polymerization of mainly styrene monomer using a complete mixing type reactor, without substantially changing an average molecular weight of a polymer formed, comprising the steps of: (a) keeping a polymerization temperature substantially constant at t(.degree.C.), (b) setting a feeding rate of the styrene monomer to A times larger rate than that in a polymerization conducted in the absence of a radical polymerization initiator, and (c) controlling an amount of the radical polymerization initiator added in the range of from (0.1/n).times.10.sup.-3 to (2.0/n).times.10.sup.-3 mol per 1 liter of the monomer, n being a number of radical generating functional groups present in one molecule of the radical polymerization initiator, such that a polymer concentration x satisfy the mathematical expression: x.gtoreq.0.3t+6.multidot.(A-1)+12 and that x be kept substantially constant, wherein A represents a ratio of a polymerization rate after being controlled to a rate of polymerization conducted in the absent of the radical polymerization initiator. The method can easily and as desired control the polymerization rate using any desired radical polymerization initiator.

Method for controlling a polymerization rate of styrene resins

A thermoplastic resin composition having excellent appearance and moldability contains:

Thermoplastic resin compositions comprising blends of polyphenylene

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 %.

Styrenic resin composition and injection- and extrusion-molded articles

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:

Injection-molded articles

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):

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Ichihara, Japan

Hayato Kihara