Catalytic polyamide acid solns prodn - useful as electrical wire coatings, having good storage props

摘要

The solns. are produced by reacting the dianhydrides of aromatic tetracarboxylic acids (e.g. pyromellitic dianhydride) with aromatic diamines (e.g. diamino-diphenylether/methane) in phenolic (aromatic hydrocarbon mixts) solvents in the presence of propylene oxide.