Ube Industries, Inc.

Akinori Otani

Takashi Kohno

Hideaki Okihara

Susumu Morishige

Hiroshi Inoue

Toshinori Hosoma

An aromatic polyimide film which is favorably employed for preparing a laminate of an aromatic polyimide film, an adhesive layer, and an electroconductive sheet is made of a polyimide prepared from a tetracarboxylic acid component containing at least 15 molar % of biphenyltetracarboxylic acid (or its dianhydride or ester) and an aromatic diamine component containing at least 5 molar % of phenylenediamine, has a specific edge tearing resistance of 11 to 22 kg/20 mm/10 .mu.m, and contains not more than 0.4 weight percent of a volatile component.

Aromatic polyimide film

An aromatic polyimide film in the form of a continuous tape having a thickness of 50 to 125 .mu.m favorably employed for manufacture of electric circuit is composed of a biphenyltetracarboxylic acid recurring unit and a p-phenylenediamine recurring unit. The polyimide film has the following characteristics: a tensile strength of not lower than 30 kg/mm.sup.2 ; a tensile modules of not lower than 500 kg/mm.sup.2 ; a linear expansion coefficient of not higher than 2.5.times.10.sup.-5 cm/cm/.degree.C.; a heat shrinkage ratio of not higher than 0.05%; a low curling having a maximum curling of not higher than 3 mm for a disk of diameter of 86 mm; and a uniform thickness having a maximum rate of inclination of not more than 3 .mu.m per 10 mm.

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Yamaguchi, Japan

Akinori Otani