Copolyamides with long-chain polyamide units

Abstract

A copolyamide composition and article molded therefrom, the molded article being transparent, being especially rigid, tough and cold impact resistant, having good resistance to solvents, and exhibiting negligible changes in mechanical properties in the conditioned state due to very low water absorption. The copolyamide composition including long-chain monomer building blocks and being comprised of from about 30 to about 96 parts by weight of at least one long-chain monomer which is suitable as a long-chain building block for a polyamide and which has from 9 to 12 carbon atoms; and from about 4 to about 70 parts by weight of precursor monomers for semiaromatic polyamides, which precursor monomers comprise at least one diamine, H.sub.2 N--R--NH.sub.2, and at least one aromatic dicarboxylic acid in an approximately equimolar ratio with one another, wherein R is a radical selected from the group consisting of a straight-chain radical having 2 to 12 carbon atoms, an aliphatic radical having 2 to 12 carbon atoms, an araliphatic radical having 7 to 12 carbon atoms, and a cycloaliphatic radical having 6 to 42 carbon atoms. Advantageously, up to about 15 mole percent of the at least one aromatic dicarboxylic acid can be replaced by a long-chain aliphatic dicarboxylic acid having 9 to 36 carbon atoms.