Teijin Limited

Toshihiro Aoyama

Keizo Shimada

Hidetsugu Yoshida

Gentaro Yamashita

Kiyoshi Yamamoto

Tadao Komoriya

Nobuo Sakaiya

Yasushi Tsuru

Moriharu Yamamoto

A new polycarbosilastyrene copolymer which comprises recurring carbosilane units of the formula I: ##STR1## and recurring silastyrene units of the formula II: ##STR2## and having easy shaping and sintering properties, is produced by ultra-violet ray treatment and/or heat treatment of a polysilastyrene material and is useful for producing a shaped sintered silicon carbide article by shaping the polycarbosilastyrene copolymer to a desired form, by applying an ultra-violet ray treatment or heat treatment to the shaped article, and by sintering the resultant corss-linked, non-fusible shaped article at an elevated temperature.

Polycarbosilastyrene copolymer, method for producing the same, and

A polycarbosilastyrene copolymer which comprises recurring carbosilane units of the formula I: ##STR1## and recurring silastyrene units of the formula II: ##STR2## is useful for producing a shaped sintered silicon carbide article by shaping the polycarbosilastyrene copolymer to a desired form, by applying an ultra-violet ray treatment or heat treatment to the shaped article, and by sintering the resultant cross-linked, non-fusible shaped article at an elevated temperature.

Process for producing shaped silicon carbide article from a

A novel 1,3,5,7-naphthalenetetracarboxylic acid, an alkali salt thereof, or an ester thereof, and a novel process for preparation thereof, and method of effective purification thereof.

1,3,5,7-Naphthalenetetracarboxylic acids and process for preparation

Growing community of inventors

Nagareyama, Japan

Toshihiro Aoyama