Ube Industries, Inc.

Yoshikazu Sasaki

Hiroshi Inoue

Hiroshi Itatani

Mikito Kashima

Ichiro Sasaki

Hataaki Yoshimoto

Kazuo Kumamoto

Shuji Yamamoto

Tadashi Miura

Sumio Toudou

Youji Negi

Kazuhiko Sakai

Disclosed is an aromatic polyamic acid solution composition comprising an aromatic polyamic acid dissolved in an amount of 5 to 40% by weight in an organic polar solvent. The aromatic polyamic acid is prepared by polymerizing substantially equimolar amounts of an aromatic tetracarboxylic acid component comprising 15 to 85 mole % of a biphenyltetracarboxylic acid or its functional derivative and 15 to 85 mole % of a pyromellitic acid or its functional derivative and an aromatic diamine component comprising 30 to 100 mole % of a phenylenediamine and 0 to 70 mole % of a diaminodiphenyl ether. The aromatic polyamic acid solution composition is formed into an aromatic polyimide film having a relatively small thermal expansion coefficient, high mechanical strength and good flexibility.

Polyamic acid solution composition and polymide film made therefrom

An aromatic polyimide film having excellent mechanical, thermal and electrical properties, is continuously produced by the steps of: preparing a dope solution having a rotation viscosity of 500-10.sup.5 poises at 100.degree. C. by uniformly dissolving aromatic polyimide in a solvent consisting of at least one phenol compound; extruding the dope solution through a T-die at 50.degree. C. or more, but at least 30.degree. C. below the boiling point of the solvent, under conditions which cause the apparent viscosity and shear stress of the dope solution to be 500-5.times.10.sup.4 poises and 10.sup.4 -10.sup.6 dyne.multidot.cm.sup.-2, respectively, to form a filmy stream of the dope solution; placing the filmy stream of the dope solution on a surface of a supporting means while heating the surface at a temperature of 50.degree. C. or more and continuously moving it along its endless path, maintaining the placed filmy stream of the dope solution on the moving, heating surface of the supporting means until the filmy stream forms a film having a uniform thickness and then the film is solidifed by evaporating the solvent therefrom to an extent that the concentration of the solvent is 50% by weight or less; continuously peeling off the solidified film from the moving heating surface of the supporting means; and drying the peeled film at a temperature of 200.degree. C. to 600.degree. C. to provide an aromatic polyimide film free from the solvent.

Process for continuously producing an aromatic polyimide film

An aromatic imide polymer laminate material comprising at least one aromatic imide polymer film consisting essentially of at least one aromatic imide polymer which comprises at least 80 molar % of at least one type of recurring unit of the formula (I): ##STR1## wherein R represents a divalent aromatic radical; and at least one metallic foil which is superimposed on and directly bonded to said aromatic imide polymer film, which laminate material is produced by heat-pressing said aromatic imide polymer film superimposed on said metallic foil at 250.degree. to 600.degree. C. under a pressure of 1 to 2,000 kg/cm.sup.2 without applying a bonding agent between the polymer film and the metallic foil.

Aromatic imide polymer laminate material and method for producing the

A polyimide solution is prepared by a process wherein a tetracarboxylic acid ingredient containing at least about 80% by mole of 3,3',4,4'-biphenyltetracarboxylic acid or its functional derivative and an aromatic diamine ingredient containing at least about 50% by mole of 4,4'-diaminodiphenyl ether are polymerized at from about 100.degree. to 300.degree. C. in phenol or a halogenated phenolic compound; the amount of the acid and diamine ingredients being approximately equimolar to each other; whereby polymerization of the tetracarboxylic acid ingredient and the aromatic diamine ingredient is effected while being accompanied by imidation. Preferably, the polymerization accompanied by imidation is effected in a manner such that at least a second half of the polymerization is carried out in a closed reaction system. The resulting polyimide solution is suitable for making therefrom shaped articles, such as films, possessing excellent mechanical properties.

Process for preparing polyimide solution

An aromatic polyimide resin composition useful for producing a film or sheet, comprises 2% by weight or more of an imide polymer having at least 90 molar % of a recurring unit of the formula (I): ##STR1## wherein R' is a divalent aromatic radical, and dissolved in an organic polar solvent consisting essentially of one or more halogenated phenol compounds of the formulae (II) or (III): ##STR2## wherein R.sup.2 is a hydrogen atom of a C.sub.1-3 alkyl radical and is a halogen atom, the halogenated phenol compound having a melting point of 100.degree. C. or less and a boiling point of 300.degree. C. or less.

Growing community of inventors

Hirakata, Japan

Yoshikazu Sasaki