GB890437A - Polycarbonamides - Google Patents

Abstract

A polycarbonamide possessing improved hydrolytic stability is made by polymerizing linear polycarbonamide-forming reactants in the presence of diamine sufficient to provide from 40 to 140 gram equivalents of amine end groups in excess of the number of carboxyl end groups per 106 grams of polycarbonamide. The polymerization is preferably effected in the presence of sodium hypophosphite monohydrate. The polycarbonamides preferably contain antioxidants, e.g. dibutyl cresol, dilauryl thiodipropionate, propyl gallate, hydroxy- and methoxy-benzophenones, cupric stearate, aldehyde-alkyl phenol condensates, ascorbyl palmitate, sodium phenyl phosphinate, butylated hydroxyanisole, gum guaiac, nordihydroguianetic acid, lecithin, oat gum, tocophenol, diphenylol propane, phenyl-b -naphthylamine, sym-phenyl-naphthyl ethylene diamine, sym-dinaphthyl ethylene diamine and certain polymeric amino compounds. In the Examples:- (1) hexamethylene diammonium adipate is polymerized in the presence of hexamethylene diamine, the resultant polycarbonamide being extruded into a ribbon, cut into pieces and coated with p 1,1-bis-(2-methyl-4-hydroxy-5-tertiary-butylphenyl) butane; (2) a polycarbonamide is made as in (1) with the addition of sodium hypophosphite monhydrate to the reaction mixture; (3) a polycarbonamide is made as in (1) with the addition of sodium hypophosphite monohydrate and a mixture of 2-mercaptobenzimidazole and cupric stearate; (4) a polycarbonamide made as in (1) is blended with N,N-di-b -naphthyl-4,41-diaminodiphenyl; (5) a polycarbonamide is made as in (1) with the addition of bis(2-methyl-4-hydroxy-5-tertiary-butylphenyl) sulphide to the reaction mixture; (6) S -caprolactam is polymerized in the presence of hexamethylene diamine and (7) hexamethylene diammonium sebacate is polymerized in the presence of hexamethylene diamine and sodium hypophosphate monohydrate. The products of the examples being exposed to water under high temperatures and pressures to test their resistance. Specifications 461,236, 506,125 and U.S.A. Specifications 2,071,250, 2,241,322 and 2,434,662 are referred to.