Asahi Kasei Kabushiki Kaisha

Asahi Kasei Kogyo Kabushiki Kaisha

Ps Japan Corporation

Ikuji Ohtani

Hajime Nishihara

Yoshikazu Suda

Hideo Kinoshita

Takeshi Yasui

Sigeru Sasaki

Akihiro Watanabe

Toshiharu Kawasaki

Kimio Imaizumi

Akihiro Wada

Kazuhiro Hosoya

Rin-ichi Kakuta

Takeshi Ikematsu

Mitsutoshi Toyama

A thermoplastic crosslinked rubber composition comprising (A) from 1 to 99 parts by weight of a hydrogenated rubber obtained by hydrogenating not less than 50% of total double bonds of at least one homopolymer rubber of a conjugated diene type monomer or a random copolymer rubber consisting of a conjugated diene type monomer unit and an aromatic vinyl monomer unit and (B) from 1 to 99 parts by weight of an olefinic thermoplastic resin, total amount of (A) and (B) being 100 parts by weight, said (A) being partially or completely crosslinked, wherein said (A) is crystalline rubber, having a crystallization temperature in a range of from &#x2212;50 to 70&#xb0; C. and a heat quantity of crystallization at peak in a range of from 3 to 100 J/g in differential scanning calorimetry (DSC method).

Thermoplastic crosslinked rubber composition

The present invention provides a method for manufacturing a styrene-based polymer having the steps of continuously feeding raw materials into one end of two or more polymerization vessels connected in series; polymerizing a styrenic monomer in the coexistence of a (meth)acrylate ester monomer by using an organic radical generating agent as an initiator by a mass or solution polymerization method of continuous process; and continuously taking out a product from another end of the polymerization vessels, wherein polymerization conditions are controlled in ranges specified by the following items (a) and (b): (a) a composition of monomers to be fed is 60 to 97% by weight of a styrenic monomer(s) and 3 to 40% by weight of a (meth)acrylate ester monomer(s); and (b) a concentration of the (meth)acrylate ester monomer(s) at any part of the polymerization vessels exceeds 1% by weight based on total monomers at any time during the polymerization.

Styrene polymer resin and composition thereof

An olefin polymer composition, which comprises a cross-linked olefin polymer composition comprising at least one cross-linking rubber like polymer (A) and an olefin resin (B), the cross-linking rubber like polymer (A) being selected from the group consisting of (1) an ethylene-&agr;-olefin copolymer, which contains an ethylene unit and an &agr;-olefin unit having 3 to 20 carbon atoms, and which is produced using a metallocene catalyst, and (2) at least one hydrogenated rubber selected from the group consisting of a homopolymer of a conjugated diene monomer and a copolymer thereof, in which rubber not less than 50% of all olefinic double bonds are hydrogenated, wherein the cross-linking rubber like polymer (A) has a weight average particle diameter of from 0.01 to 3 &mgr;m.

Olefin polymer composition

High impact thermoplastic resin composition

Disclosed is a thermoplastic elastomer composition which comprises (A) a thermoplastic resin containing a polystyrene resin, (B) a rubber-like polymer obtained by partially or completely crosslinking an ethylene-&agr;-olefin copolymer and (C) a compatibilizing agent, the amount of the component (B) being 40-90 parts by weight and the amount of the component (C) being 0.1-40 parts by weight based on 100 parts by weight of the components (A), (B) and (C) in total. According to the present invention, an elastomer composition excellent in abrasion resistance can be provided.

Thermoplastic elastomer composition

A thermoplastic crosslinked rubber composition comprising (A) from 1 to 99 parts by weight of a hydrogenated rubber obtained by hydrogenating not less than 50% of total double bonds of at least one homopolymer rubber of a conjugated diene type monomer or a random copolymer rubber consisting of a conjugated diene type monomer unit and an aromatic vinyl monomer unit and (B) from 1 to 99 parts by weight of an olefinic thermoplastic resin, total amount of (A) and (B) being 100 parts by weight, said (A) being partially or completely crosslinked, wherein said (A) is crystalline rubber, having a crystallization temperature in a range of from &minus;50 to 70&deg; C. and a heat quantity of crystallization at peak in a range of from 3 to 100 J/g in differential scanning calorimetry (DSC method).

Optical materials having well balanced properties such as high heat resistance, low hygroscopicity and low double refractivity. The optical materials are derived from a low hygroscopic, random copolymer comprising units of methacrylic acid and ester derivatives, and units of a six-membered ring acid anhydride.

Low-hygroscopic copolymer

A novel random copolymer containing, in specific ratios, methyl methacrylate units, aromatic vinyl compound units, methacrylic acid units, hexagonal anhydride units and hexagonal imide units of the formula ##STR1## has been found to have excellent optical properties, mechanical strength, heat distortion resistance, heat decomposition resistance and oil resistance, and have low water absorption. The copolymer can advantageously be employed as a material for parts of light electric apparatus, engineering plastics, lenses, optical fiber cables, and is especially useful as a material for a substrate of optical discs.

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Yokohama, Japan

Ikuji Ohtani