GB737184A - Production of polyamides - Google Patents

Abstract

Polyamides are prepared by intimately mixing an aqueous solution of a polyamine with a water-immiscible organic solvent solution of a dicarboxylic acid dichloride in the presence of an acid binding agent at temperatures from - 15 DEG to 50 DEG C. If necessary a mono- or polyhydric alcohol may be present as anti-freeze agent. The process may be discontinuous or continuous, the polymer precipitating as a powder. The Specification lists a large number of amines, acids, acid binding substances and dispersing agents. In examples: (1) a solution of 1 mol. of sebacyl chloride in toluene was gradually added, with stirring, to an aqueous solution of 1 mol. of tetramethylene diamine and 1 1/2 mols. of sodium carbonate at 0 DEG C. A 58.3 per cent yield of polymer of 0.81 intrinsic viscosity was obtained. (2) To a solution of 1.5 mols. hexamethylene diamine hydrochloride at 0 DEG C. was added, with stirring, a solution of 1.5 mols. adipyl chloride in toluene and an aqueous solution of N-butyl-N-lauryl-b -amino ethane sulphonic acid sodium salt. An aqueous solution of 6 3/4 mols. sodium hydroxide was then added, with stirring, over a period of 4 minutes. A polymer precipitated immediately, in 44.2 per cent yield, having an intrinsic viscosity of 0.24. (3) An aqueous solution of 46.5 parts per litre of hexamethylene diamine, 64 parts per litre of sodium carbonate and 30 parts per litre of sodium lauryl sulphate solution, and a toluene solution of 37 parts per litre of adipyl chloride were added, the latter solution at twice the rate of the former, to a reaction zone of restricted size. The contact time in the zone was 2 minutes. A 37.5 per cent yield of polymer of intrinsic viscosity 1.14 was obtained. The process of the invention enables polymers to be prepared from short chain intermediates, side reactions, such as 5- or 6-membered ring formation, being avoided.