Sumitomo Chemical Company, Limited

Michihisa Isobe

Shozaburo Imai

Takashi Maruyama

Katsuji Ueno

Yoshiharu Tatsukami

Masahiko Moritani

Masahiro Niwano

Taketsugu Yamamoto

Hideaki Matsuura

Katsuhiko Iwasaki

Atsushi Terahara

Kenji Manabe

Haruo Inoue

Kazuhiro Yokoo

Iko Ito

A polymer electrolyte comprising a sulfonated polyethersulfone having an ion-exchange group equivalent weight of 870 to 5000 g/mol, which is obtainable by sulfonating a polyethersulfone having the structural unit represented by the following structural formula, ##STR1## The polymer electrolyte is cheap, easily mold-processable by virtue of soluble property in organic solvent and thermoplastic property, easily film-processable, highly water-resistant, and suitable for a fuel cell.

Polymer electrolyte and process for producing the same

An optical device comprising a mixture of a polymer constituted mainly of aromatic vinyl monomer units and polyphenylene ether, characterized in that the average molecular weight of the polyphenylene ether is from 0.3 to 0.7 expressed in terms of the intrinsic viscosity measured in chloroform at 25.degree. C.

Optical device

There is disclosed herein an optical disk substrate comprising a copolymer produced by polymerizing 50 to 65% by weight of methyl methacrylate (a) units, 20 to 35% by weight of tricyclo[5.2.1.0.sup.2.6 ]deca-8-yl methacrylate (b) units, 5 to 25% by weight of cyclohexyl methacrylate (c) units and 1 to 5% by weight of acrylic ester (d) units.

Optical disk substrate

Optical resin material having improved birefringence

A process for producing polyphenylene oxide which comprises contacting a phenolic monomer with oxygen in the presence of a catalyst composed of a manganese (II) salt and an ortho-hydroxyazo compound represented by the following formula: ##STR1## wherein A and B represent identical or different arylene ring having a valency of at least 2 and having an oxy group and an azo group directly linked to the ortho carbon atoms of the arylene ring and R represents hydrogen or lower alkyl group, or in the presence of said catalyst and an amine, in a polymerization solvent containing a base and thereby subjecting said phenolic monomer to an oxidative polymerization.

Process for producing polyphenylene oxide

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Tokyo, Japan

Michihisa Isobe