Asahi Kasei Kogyo Kabushiki Kaisha

Asahi-dow Limited

Akihiro Wada

Kichiya Tazaki

Yukihisa Mizutani

Rin-ichi Kakuta

Tamotsu Tahara

Hiroshi Suzuki

Akihiro Watanabe

Shinji Hasegawa

Ikuji Ohtani

Jun Sugiyama

Kenji Ohuchi

A novel optical element substrate which comprises a random copolymer comprising, in specific weight proportions, a methyl methacrylate unit, an aromatic vinyl compound unit, an unsaturated aliphatic acid unit and a hexagonal acid anhydride unit of the formula ##STR1## The substrate has excellent heat resistance, thermal stability, transparency, resistance to scratching and metal layer corrosion preventive properties and exhibits advantageously low double refraction and warpage. The novel substrate can be advantageously employed as a substrate for an optical element such as an optical disc, e.g. a digital audio disc, a video disc and a disc capable of being directly read after recording, a mirror, a lens and the like.

Optical element substrate

A resin composition comprising (A) a copolymer comprising hexagonal units selected from hexagonal acid anhydride units, hexagonal imide units and mixtures thereof, methyl methacrylate units, (meth)acrylic acid units and optionally aromatic vinyl compound units, (B) a graft copolymer rubber, and (C) at least one polymer selected from a polyamide and a polycarbonate, wherein the weight proportions of components (A), (B) and (C) relative to the total weight of components (A), (B) and (C) are in the ranges of from 5 to 50%, from 5 to 50% and from 45 to 80%, respectively. The resin composition has surprisingly improved impact strength not possessed by any of the individual component polymers of the resin composition, while maintaining advantageous properties, such as moldability, other mechanical strengths, rigidity, heat resistance, moisture resistance, chemical resistance and dimensional stability, attributed to the individual component polymers. Advantageous applications of the resin composition of the present invention are found in the manufacturing of various parts for automobiles, household electrical appliances and business machines.

Resin composition comprising a polyamide or polycarbonate

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.

Random copolymer containing hexagonal imide units, a process for

In injection molding thermoplastic resin compositions containing reinforcing materials and/or fillers, high quality molded articles superior in surface gloss and exhibiting substantially no surface defect can be obtained, by employing a technical measure, in which only superficial layer of the inner wall surface of the mold is selectively heated, by high-frequency induction heating, to a temperature above the heat distortion temperature of the thermoplastic resin composition employed prior to injection molding and cooling and solidifying the resin.

Injection molded articles with improved surface characteristics

Injection molded articles with improved surface characteristics,

A molding material structure of a thermoplastic resin composition comprising (1) at least one pillar-shaped body made of a bundle of glass fiber filaments and a non-oriented thermoplastic resin and (2) an outer covering layer of an oriented thermoplastic resin compatible with the resin in said inner body is found to produce molded articles in which glass fiber filaments are dispersed uniformly in the resin matrix with longer average length to improve various properties of molded articles, especially impact strength.

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Inagi, Japan

Akihiro Wada