PROCESS FOR THE PREPARATION OF 4,4'-BIS(4-AMINOPHENOXY)-DIPHENYL SULPHONE

摘要

23443-445 A process for the preparation of 4,4'-bis(4-amino-phenoxy)diphenyl sulfone of high purity is disclosed. The process comprises converting 4-aminophenol to the corresponding alkali metal phenolate with an alkali metal hydroxide, reacting the phenolate with a 4,4'-dihalogenodiphenyl sulfone in an organic solvent at 120.degree. to 200.degree.C, precipitating the product by means of a precipitant and separating it off. By using specific narrow molar ratios of alkali metal hydroxide to 4-aminophenol and of 4-aminophenol to 4,4'-dihalogenodiphellyl sulphone and by using a dialkylamide as solvent, products having melting points above 195.degree.C are obtained without recrystallization. The product is useful as monomer for the preparation of high-melting polyamides, polyimides and polyamidoimides and as a curing agent of epoxides.