PROCESS FOR THE PREPARATION OF COPOLYAMIDES BASED ON HEXAMETHYLENEDIAMINE, ADIPIC ACID, POSSIBLY AT LEAST ONE OTHER SHORT CHAIN CARBOXYLIC DIACID AND DIMER ACID

摘要

Homogeneous copolyamides having high melting points and good flexibility, well adapted for the production of textile materials and plastic shaped articles, are prepared by prepolymerizing lower dicarboxylic acid(s) with an excess of hexamethylenediamine in the presence of a catalytically effective amount of a strong inorganic or organic oxyacid, or alkali or alkaline earth metal salt thereof, and thence polycondensing the resulting prepolymer with a fatty acid dimer.