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US 4,362,863 AGranted
Process for production of polyimide resins
AssigneeNitto Electric Industrial Co., Ltd.
InventorsMakoto Kojima, Hideki Yane
Life of this patent
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Abstract
A process for producing an aliphatic polyimide resin is described, comprising reacting an aliphatic tetracarboxylic acid with a diamine in the presence of a second acid having a higher electrolytic dissociation constant than the aliphatic tetracarboxylic acid.
Claims10
A process for producing an aliphatic polyimide resin by reacting an aliphatic tetracarboxylic acid with a diamine represented by the formula H.sub.2 N--R--NH.sub.2, wherein R is a divalent group containing at least two carbon atoms,
- wherein the improvement comprises conducting the reaction in the presence of a second acid having a higher electrolytic dissociation constant than the aliphatic tetracarboxylic acid in an amount of from 0.01 to 1.0% by weight based on the total weight of the reaction system.
Dependencies are inferred from the claim text.