GB568977A - Improvements in or relating to polyamide compositions - Google Patents

Abstract

Polyamide compositions are prepared by heating at temperatures above 180 DEG C., but below the decomposition temperature, until homogeneity is obtained, a melt comprising a synthetic linear polyamide wherein the majority of the amido groups are secondary and which has an intrinsic viscosity of at least 0.4, and at least one further synthetic linear polyamide in which at least 50 per cent of the amido groups are tertiary, the lateral substituents on its amido nitrogens being hydrocarbon groups attached to the nitrogens through aliphatic carbon atoms, and which has an intrinsic viscosity of at least 0.2, the polyamides being blended in such proportions that from 1 per cent to 50 per cent of the amido groups in the resulting composition are tertiary. The tertiary amido polyamides appear to function as plasticizers for the secondary amido polyamides. Homogeneity is generally reached in a period of from 5 to 60 minutes after complete fusion has been effected, and some amide interchange probably takes place during heating. Many starting polyamides are specified, and examples are given of the preparation of blends from: (1) poly-N : N1-dimethylhexamethylene adipamide and polyhexamethylene sebacamide; (2) poly - N : N1 - diethylhexamethylene adipamide and the interpolymerization product of hexamethylenediammonium adipate, hexamethylenediammonium sebacate, and epsilon-aminocaproloctam; and (3) polyhexamethylene adipamide and the interpolymerization product of N : N1 - dimethylhexamethylenediammonium adipate and hexamethylenediammonium adipate. The products can be formed into fibres, films, or other articles, and they exhibit improved receptivity for many dyestuffs. Specifications 461,236, 461,237, 474,999, 501,527, 535,138 and 562,370, and U.S.A. Specifications 2,130,523 and 2,193,529 are referred to.