| abstract |
Novel thermoplastic copolyesters useful in fibers, films and molding resins are prepared by the transesterification of (a) straight or branched chain poly(1,4-butylene terephthalates) and (b) a polyester of (i) a cycloaliphatic 1,2-dicarboxylic acid or a derivative thereof, etc., and (ii) 1,4-butanediol. Compositions comprising the new copolymers with high molecular weight poly(1,4-butylene terephthalates) and with reinforcing agents are also disclosed. |