Ube Industries, Inc.

W. R. Grace Co.-conn.

Pi Material Research Laboratory

Pi Materials Research Laboratory

Hiroshi Itatani

Mikito Kashima

Akinori Shiotani

Hataaki Yoshimoto

Ichiro Sasaki

Akiyoshi Yokota

Keigo Nishihira

Masayoshi Yamashita

Masaoki Matsuda

Yoshikazu Sasaki

Shuji Yamamoto

Yoshihiro Oie

Hiroyuki Yamamoto

Hiroshi Inoue

Thomas Andrew Blinka

Kozo Fujii

Kenji Nishimura

Shinichiro Uchiumi

Toshihiro Inaike

I-Fan Wang

Mikio Fujimoto

Yasutaka Tasaki

Masao Eguchi

Tetuo Kato

Toshiharu Yamasaki

Schinichiro Uchiumi

Shinichi Furusaki

Sadakazu Hokamura

Motozoh Yoshikiyo

Yuji Yamazaki

Tsutomu Suehiro

Masami Aikawa

Aromatic diamines having a carboxylic acid group and various other diamines are reacted with aromatic tetracarboxylic dianhdyrides in organic polar solvents to provide polyimides. Polyimide compositions for electrodeposition which comprise the neutralized salts of the polyimides, water and poor solvents for the polyimides have good keeping quality and when electrodeposited on electrically conductive materials, can form polyimide coats that have high levels of appearance, smoothness and denseness while exhibiting good physical and chemical characteristics in such aspects as heat resistance, electrical insulation and chemical resistance.

Polyimide compositions for electrodeposition and coatings formed of the

Polyimide soluble in an organic polar solvent was prepared by heating the solution in the presence of a binary catalyst having low boiling point. Block copolyimides consisting of more than three components were prepared by the sequential addition process in the presence of the binary catalyst. Polyimide resins were prepared without the separation of polyimides and catalysts because of evaporating consequently catalysts and solvent. The binary catalyst comprise one compound selected from .gamma.-valerolactone and crotonic acid, and one compound selected from pyridine and N-methylpyrrolidone.

Process for preparing polyimide resins

A tri-component polyimide copolymer and the process of preparing the copolymer are disclosed. A mixed reaction medium or solvent system comprising phenol and at least one compound of resorcinol, 1,6-dimethyl phenol and 4-methoxy phenol is used to produce the copolymer by direct imidization without isolating or purifying the imide oligomer as an intermediate.

Tri-component polyimide composition and preparation thereof

A polyimide resin composition with outstanding heat resistance and mechanical properties is disclosed, along with a novel method of its preparation. A tetracarboxylic acid or its derivative and an aromatic diamine are dissolved in a solvent system of mixed phenols and are both polymerized and imidized on one step.

Polyimide resin and preparation thereof

A novel class of polyimides useful in making semipermeable membranes for gas separation is synthesized by the reaction of 4,4'-[hexafluoroisopropylidene]-bis-[phthalic anhydride] (6FDA) with 3,7-diamino-2,8-dimethyldiphenylenesulfone (AMPS). In lieu of the two methyl groups the diamine may be substituted by H or C.sub.2-4 alkyl. Membranes made from the polyimides have high permeability for CO.sub.2 from mixtures containing CO.sub.2 and other gases such as CH.sub.4 and have commercially acceptable selectivity.

Gas separation material

A liquid thermal accumulator composition comprising a dicarboxylic acid anhydride, an alcohol and a monoester of the dicarboxylic acid and the alcohol. A process for accumulation of thermal energy utilizing said composition is also disclosed.

Liquid thermal accumulator composition and thermal accumulation process

A biphenyltetracarboxylic ester, particularly, 3,3',4,4'-biphenyltetracarboxylic tetraester, is prepared in an increased yield by first oxidative coupling, at 140.degree. C. to 260.degree. C., an o-phthalic diester with a molecular oxygen-containing gas, for example, air, in the presence of a catalyst comprising predetermined amounts of a Pd salt, a basic bidentate ligand compound, and a Cu salt to convert a portion of the o-phthalic diester to the corresponding biphenyltetracarboxylic ester and by additionally oxidative coupling in one or more steps, in each step, the remaining portion of o-phthalic diester with a molecular oxygen-containing gas at 140.degree. C. to 260.degree. C. while controlling the composition of the catalyst to an extent such that the entire molar amount of the Pd salt is 0.0001 to 0.01 time that of the o-phthalic diester, the entire molar amount of the ligand compound is 0.5 to 4 times that of the Pd salt and the entire molar amount of the Cu salt is 0.01 to 5 times that of the Pd salt.

Method for producing biphenyltetracarboxylic esters

An aromatic polyimide composition usable for producing shaped articles, for example, films, or as varnish, lacquer, or bonding agent, comprises a high molecular weight aromatic polyimide resin which is a polycondensation-imidization product of an aromatic tetracarboxylic acid component comprising 50 molar % or more of 3,4,3',4'-biphenyltetracarboxylic acid, anhydride, salt, or ester with an aromatic diamine component including 50 molar % or more of 4,4'-diaminodiphenylether, and which is dissolved in a mixed solvent consisting essentially of 10% by weight or more of a first solvent component selected from naphthol and resorcin and the balance of a second solvent component selected from phenol and cresols.

Aromatic polyimide composition comprising mixed solvent

In a process for producing an iodo-aromatic compound which comprises iodinating an aromatic compound having an electron-donating substituent bonded to the benzene ring with iodine in the presence of a solvent, the improvement wherein about 1/2 to about 10 moles, per mole of iodine added to the reaction system, of nitrogen dioxide (NO.sub.2) is added in the form of NO.sub.2 to the reaction system, and the reaction is carried out in the presence of nitrogen dioxide.

Process for producing iodo-aromatic compounds

Disclosed is an improved process for preparing diesters of malonic acid by subjecting ketene, carbon monoxide and an ester of nitrous acid to a liquid phase reaction in an organic solvent, in which the reaction is carried out in the presence of a catalyst of a platinum group metal complex represented by the formula:

Process for preparing diesters of malonic acid

A biphenyltetracarboxylic tetraester, especially, 3,3',4,4'-biphenyltetracarboxylic tetraalkyl ester, is produced by bringing an orthophthalic diester, especially, orthophthalic dialkylester, into contact with a molecular oxygen-containing gas in the presence of a catalyst consisting of a mixture of a palladium salt with 2,2'-bipyridyl or a chelating reaction product of a palladium salt with 2,2'-bipyridyl, so as to promote oxidative coupling of the orthophthalic diester.

Method of producing biphenyltetracarboxylic esters

A biphenyl compound is produced from a corresponding aromatic monocyclic compound at a high yield thereof and a high percent selectivity thereto, by dehydrogenatively dimerizing the aromatic monocyclic compound with molecular oxygen in the presence of oxalic acid together with a organic palladium salt catalyst, under a pressure higher than the atmospheric pressure.

Process for producing biphenyl compounds

A biphenyltetracarboxylic tetraester, especially, 3,3',4,4'-biphenyltetracarboxylic tetraalkyl ester, is produced by oxidative coupling an orthophthalic diester, especially, orthophthalic dialkylester, in a molecular oxygen-containing atmosphere in the presence of a catalyst consisting of a mixture of a palladium salt with 1,10-phenanthroline and/or 2,2'-bipyridyl or a chelating reaction product of a palladium salt with 1,10-phenanthroline or 2,2'-bipyridyl.

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

Chiba, Japan

Hiroshi Itatani