Ube Industries, Inc.

Ntn-Rulon Industries, Co., Ltd.

Akihiro Kunimoto

Seiichirou Takabayashi

Yuji Matsui

Morio Nakamura

Tatuaki Maeda

Noboru Umemoto

Seiichiro Takabayashi

A method of continuously forming a shaped long article of an aromatic polyimide power including supplying a powdery mixture containing an aromatic polyimide powder having a heat loss ratio of not more than 2 wt. % and a mean particle size in the range of 0.1 to 40 .mu.m, and a small amount of a fluororesin powder to a ram-extrusion apparatus having a mold and performing alternately, at a temperature of not lower than 300.degree. C., filling the mold with the above mixture and ram-extruding the same at a pressure in the range of 100-1,500 kg/cm.sup.2. An extruded long article of an aromatic polyimide which has a specific gravity of more than 1.380, a radial crushing strength of not less than 800 kg/cm.sup.2, and a coefficient of linear expansion in the radial direction being less than that in the longitudinal direction.

Continuous preparation of shaped long articles of polyimide

A shaped electroconductive aromatic imide polymer article comprising an aromatic imide polymer matrix and 10% to 40% by weight of short cut carbon fibers 1 to 30 .mu.m thick and 0.05 to 3.0 mm long dispersed in the matrix, is produced by admixing a slurry of the short cut carbon fibers having a limited moisture content of 1.0% or less in a polymerization medium, with a polymerization mixture containing an aromatic tetracarboxylic acid component and an aromatic diamine component, by subjecting the resultant admixture to a polymerization procedure to prepare a dope comprising a resultant polymerization product, the carbon fibers and the polymerization medium, and by subjecting the dope to shaped article-producing procedures in which the dope is shaped into a desired form and the shaped dope is solidified by removing the polymerization medium to provide a desired shaped article.

Shaped electroconductive aromatic imide polymer article and process for

A process for the production of a polyimide film having an increased adhesiveness which includes the steps of: evenly coating a surface treating solution which contains a heat-resistant surface treating agent of aminosilane type, epoxysilane type or titanate type in an amount not less than 0.5 wt. % on a surface of a solid film comprising an aromatic polymer composition which contains 100 parts by weight of an aromatic polyamic acid and 5-150 parts by weight of an organic polar solvent and heating the solid film having the coated surface treating solution at a temperature of 100.degree.-600.degree. C., to imidize the polyamic acid constituting the solid film as well as to dry the film.

Process for the preparation of polyimide film

An abrasive sheet having an excellent flexibility, mechanical strength and heat resistance comprises an aromatic imide polymer matrix and abrasive particles having an average size of 0.1 to 50 .mu.m and is prepared by evenly dispersing the abrasive particles in an organic polar solvent, mixing the resultant dispersion with a polymerization mixture consisting of an acid component comprising, as a major acid ingredient, a biphenyltetracarboxylic acid or an dianhydride thereof with a diamine component comprising an aromatic diamine, while polymerizing the acid and diamine components at 0.degree. C. to 80.degree. C. into an aromatic polyamic acid, forming the resultant dope dispersion into a thin layer and solidifying the thin layer while imidizing the aromatic polyamic acid into a corresponding aromatic imide polymer.

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Ube, Japan

Akihiro Kunimoto