| abstract |
Transparent, high molecular-weight copolyamides having high glass transition temperatures, based on: n (1) lactams or omega-aminocarboxylic acids; n (2) terephthalic acid, isophthalic acid, esters thereof, ester forming derivatives thereof, or mixtures thereof; and n (3) mixtures of diamines; the copolyamide consisting of: n (A) about 25 to 60 mole % of at least one omega-aminocarboxylic acid having at least 11 C atoms or its lactams; n (B) about 40 to 75 mole % of an equivalent mixture of terephthalic acid, isophthalic acid or a mixture thereof, and a diamine mixture of about 80 to 50 mole % referred to the total diamines, of isophorone diamine and correspondingly about 20 to 50 mole % of diamines of the general formula ##STR1## where R 1 and R 2 are hydrogen atoms or alkyl groups having 1 to 4 C atoms and the sum of A+B amounts to 100 mole %. n The copolyamides have utility as transparent, impact resistant molded articles. |