Nitto Electric Industrial Co., Ltd.

Daikin Kogyo Co., Ltd.

Nitto Denki Kogyo Kabushiki Kaisha (Nitto Electric Industrial Co., Ltd.)

Osaka Gasu Kabushiki Kaisha

Nitto Denki Kogyo Kabushiki Kaisha

Osaka Gasu Kabushiki Kaisha (Osaka Gas Company Ltd.)

Yasuhiro Moriyama

Masao Nakamura

Takashi Ishizuka

Minoru Komura

Satoshi Ogawa

Syuichi Nakamura

Tomihisa Ueno

Syozo Fumoto

Kiyoshi Oshita

Jyuzaemon Hoashi

Atsuo Yoshimura

Kanji Kawakami

Shoji Suzuki

A porous polytetrafluoroethylene material produced by forming a mixture of an adequate amount of a liquid lubricant and polytetrafluoroethylene fine powder having an average molecular weight of at least 6,000,000, an amorphous index larger than 0.1 and a number average primary particle size of 0.1 to 0.8 microns, and a clear endothermic peak at a temperature of 347.+-.3.degree. C. and an another endothermic peak or shoulder at a temperature between 330.degree. C. and the temperature of said clear endothermic peak on a crystalline melting chart recorded by a differential scanning calorimeter, removing the lubricant to obtain an unsintered PTFE material and expanding the unsintered polytetrafluoroethylene material at least monoaxially at a temperature higher than the melting point of polytetrafluoroethylene.

Porous polytetrafluoroethylene material

A heat-shrinkable polyimide film which comprises a polyimide film prepared by converting at least about 50% by weight of polyamide acid obtained by reacting a biphenyltetracarboxylic acid dianhydride represented by the general formula ##STR1## with an aromatic diamine into polyimide, and stretched in at least one direction to provide heat-shrinkability, and a process for producing the film.

Production of heat-shrinkable polyimide films

Heat shrinkable material comprising a heat shrinkable substrate and a layer of different kinds of adhesives provided on the substrate, which exhibits excellent impact resistance and adhesion properties over a wide temperature range.

Heat shrinkable material

A process for producing a polyimide tube which comprises

Process for producing polyimide tubes

A heat-fusible polyimide compound film which comprises a polyimide film and a heat-fusible layer composed of a polyimide precursor having a volatile material content of about 5 to about 50% by weight which is prepared by converting a part of a polyamide acid obtained by reacting a biphenyltetracarboxylic acid dianhydride represented by the general formula ##STR1## with an aromatic diamine into imide, provided on at least one surface of the polyimide film, and a process for producing the film.

Heat fusible polyimide compound films and process for producing the same

Thermoshrinkable or thermoexpansive tubes for corrosion prevention or lin of piping are disclosed which have their inner and/or outer walls covered with at least one protective cover to keep them clean from dust, dirt, water or any other foreign matter which might interfere with adhesion to the pipe connection, thus causing corrosion or poor lining.

Protective cover for a thermoresponsive tube

Thermoshrinkable or thermoexpansive tubes for corrosion prevention or lining of piping are disclosed which have their inner and/or outer walls covered with at least one protective cover to keep them clean from dust, dirt, water or any other foreign matter which might interfere with adhesion to the pipe connection, thus causing corrosion or poor lining.

Growing community of inventors

Ibaraki, Japan

Yasuhiro Moriyama