Hitachi Chemical Company, Ltd.

Shozo Kasai

Yasunori Okada

Hiroshi Nishizawa

Yoshiyuki Mukoyama

Yuichi Osada

Nobuyuki Hayashi

Isao Uchigasaki

Shigeo Tachiki

Mineo Nakano

Masahiro Abo

Toyoji Oshima

A heat resistant resin composition comprising (A) a polyamideimide resin soluble in a cresol type solvent obtained by using a lactam as a reactant, and (B) at least one member selected from the group consisting of a polyester resin, a polyesteramide resin, a polyesterimide resin and a polyesteramideimide resin, preferably heated for conducting a reaction, gives coatings excellent in heat resistance, thermal shock resistance, wear resistance, resistance to hydrolysis, crazing resistance, etc., suitable for enamelled wire.

Heat resistant resin composition

An insulated wire having excellent heat resistance, abrasion resistance and flexibility can be prepared by coating on an electric conductor directly or via another insulating material a polyamide-imide resin composition prepared by reacting an aromatic diisocyanate and a tricarboxylic acid anhydride in the presence of a basic solvent while adjusting the resin content at 40% by weight or more, and adding to the reaction system a lactam in an amount of 0.1 to 1.0 mole per mole of the aromatic diisocyanate, and if necessary, an alcohol and/or an oxime in an amount of 0.01 to 0.5 mole per mole of the aromatic diisocyanate before, during or after the above-mentioned reaction to mask terminal functional groups and to make the reduced viscosity of the composition 0.1 to 0.27, and baking the resin composition.

Insulated wire

A heat resistant resin produced by reacting (A) a polyamideimide resin with (B) an alcohol component and (C) an acid component with heating is soluble in a cresol type solvent and gives coatings excellent in heat resistance, thermal shock resistance, wear resistance, resistance to hydrolysis, etc., suitable for enamelled wire.

Heat resistant resin and process for producing the same

A polyamide-imide resin which can give a varnish having a high resin content, excellent in storage stability and heat resistant final products can be produced by reacting an aromatic diisocyanate with a tricarboxylic acid anhydride in the presence of a basic solvent while adjusting the resin content at 40% by weight or more, and adding a specific amount of lactam and a specific amount of an alcohol and/or an oxime separately before, during or after the above-mentioned reaction so as to adjust the reduced viscosity of the resin to 0.10 to 0.27.

Method for preparing polyamide-imide resin

Heat resistant resin composition comprising reaction product of

A resin composition comprising (A) a reaction product obtained by reacting (a) a polyvalent isocyanate, (b) a polyvalent carboxylic acid anhydride, and if necessary, (c) a polyvalent carboxylic acid, in an organic solvent, and (B) a compound having active hydrogen in the molecule except for a phenolic compound, shows excellent heat resistance and storage stability. Insulated wires obtained by coating said resin composition on an electric conductor directly or indirectly are advantageously produced.

Heat resistant resin composition and insulating wire using the same

A polyester resin, polyester-imide resin or polyester-amide-imide resin dissolved in a solvent containing 60% by weight or more of at least one polyhydric alcohol derivative selected from the group consisting of R.sub.1 COO(CHR.sub.2 CH.sub.2 O).sub.n H, R.sub.1 COO(CHR.sub.2 CH.sub.2 O).sub.n COR.sub.3, R.sub.1 O(CHR.sub.2 CH.sub.2 O).sub.n COR.sub.3 and R.sub.1 O(CHR.sub.2 CH.sub.2 O).sub.n R.sub.4, wherein R.sub.1, R.sub.3 and R.sub.4 are independently lower alkyl, aryl or aralkyl; R.sub.2 is hydrogen or methyl; and n is an integer of 1 to 3, gives an electrical insulating coating having excellent storage stability and high resin concentration without causing defects of phenols when used as a solvent.

Electrical insulating coatings

An electrical insulating resin composition comprising a resin obtained by reacting (a) one or more tri- or higher polyhydric alcohols and/or tri- or higher polybasic acids, (b) one or more dihydric alcohols, (c) one or more dibasic acids, (d) one or more monobasic acids containing one or more aromatic rings in the molecule, and/or (e) one or more monohydric alcohols containing one or more aromatic rings in the molecule, and if desired (f) one or more compounds containing or being able to form one or more 5-membered imide rings, can give high solids varnishes without lowering the molecular weight of the resin produced. Said varnishes can give coating films excellent in heat resistance, flexibility and mechanical strengths.

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Hitachi, Japan

Shozo Kasai