GB872328A - Production of stabilised polyamides - Google Patents

Abstract

872,328. Poly #-caprolactam. MONSANTO CHEMICAL CO. Dec. 12, 1957 [Dec. 13, 1956], No. 38638/57. Class 2(5). #-caprolactam is polymerized by heating under substantially anhydrous conditions in the presence of (a) a catalytic amount of an alkali or alkaline earth metal or of a compound thereof which acts as an anionic polymerization catalyst and (b) a compound containing at least one tertiary nitrogen atom, one group linked to the nitrogen atom being a carbonyl, thiocarbonyl or sulphonyl group and a second being a carbonyl, thiocarbonyl, sulphonyl or nitroso group, the compound being free from primary amino groups. Specified metal compounds are the hydrides, fluorohydrides, oxides, hydroxides and carbonates, lithium, sodium and potassium alkyls, e.g. butyl lithium and sodium phenyl. Specified compounds containing tertiary nitrogen atoms are N-substituted imides, e.g. N-acetyl-2- pyrrolidone; cyclic imides of dicarboxylic acids, e.g. N-phenyl succinimide; N, N-diacyl primary alkyl and arylamines and N, N-diacyl acylamides, e.g. N, N-diacetyl methylamine; the N, N<SP>1</SP>, N<SP>11</SP>- trimethyl ester of isocyanuric acid; N-acyl sulphonamides and sulphonimides, e.g. N-acetyl- N-ethyl-p-toluene sulphonamide; disulphonamides of primary alkyl and aryl amines, e.g. N, N-di(p-toluenesulphonyl) anilide; N-nitrosoamides which do not have a free hydrogen atom on the amide group, e.g. N-nitroso-2-pyrrolidone and N-nitrososulphonamides, e.g. N-nitroso-N- methyl-benzene sulphonamide, many examples of such compounds being listed. The compound containing the tertiary nitrogen may be formed in situ in the reaction mixture by reacting the #- caprolactam with an isocyanate or ketone. In the examples, #-caprolactam is polymerized in the presence of sodium hydride and (1) N-acetyl- #-caprolactam; (2) N, N-diacetyl methylamine; (3) ethyl isocyanate; (4) N-acetyl-N-methyl-ptoluene sulphonamide; (5) 4, 4<SP>1</SP>-diisocyanato diphenyl methane; (6) 2, 4-tolylene diisocyanate; (7) the tri-isocyanate formed by reacting 1, 1, 1- trihydroxymethyl propane with 2, 4-tolylene diisocyanate; (8) N-phenyl succinimide; (9) N-methyl phthalimide and (10) N-acetyl-2- pyrrolidone, the products of the examples being ground, leached and dried.