US 3,937,673 A · Modified amide-imide resins and method of making the same

Abstract

A modified completely imidized aromatic polyamide-imide resin which can be applied from conventional phenolic solvents such as cresylic acid, phenols, cresols and the like. The method of the invention includes reacting an aromatic diisocyanate and an aromatic tricarboxylic acid anhydride in an aprotic solvent, modifying the reaction product with an aliphatic dicarboxylic acid, and diluting the same to an appropriate degree with a solvent. Solutions of the resin having relatively low viscosity and a relatively high resin content can also be made by the method of the invention. The modified polyamide-imide resin of the invention has thermal stability and toughness approaching non-modified aromatic polyamide-imide resins and are fully useful as such resins as insulation materials in the electrical industry.

Claims22

Dependent claims

A composition of matter comprising the reaction product of aromatic tricarboxylic acid anhydride reactant and aromatic diisocyanate reactant and aliphatic dicarboxylic acid reactant having more than 6 carbon atoms reacted in a reaction solution comprising aprotic solvent having solvency parameters within the following ranges:

.delta.d 8.0 through 10.0, .delta.p 0.3 through 4.5, .delta.h 0.7 through 4.0 and said reactants at a temperature ranging from about 150.degree.C. to about 200.degree.C., said reactants being a major portion of said reaction solution, said dicarboxylic acid reactant being present in an amount which is greater than about 10 mol percent and less than about 50 mol percent of said anhydride reactant.

Dependencies are inferred from the claim text.

Modified amide-imide resins and method of making the same

Life of this patent

Modified amide-imide resins and method of making the same

Life of this patent

Abstract

Claims22