Fast crystallizing polyester resin containing three-component crystallization system

Claim 1

A molding composition comprising (A) 20-90% by weight based on the total of components A, B, C, D and E of a matrix resin having an inherent viscosity of at least 0.4, said matrix resin being selected from the group consisting of polyethylene terephthalate homopolymers, polyethylene terephthalate/polybutylene terephthalate mixtures, polyethylene terephthalate/polybutylene terephthalate copolymers, and mixtures thereof, wherein said polyethylene terephthalate/polybutylene terephthalate copolymers and mixtures contain at least 70% by weight ethylene terephthalate units, (B) 1-15 parts by weight per hundred parts of matrix resin (A) of polyalkylene oxide soft segments incorporated into the polymer chain of matrix resin A, said polyalkylene oxide soft segments having a molecular weight of 200-3250, (C) 1-15 parts by weight per hundred parts of matrix resin (A) of a plasticizer of the formula ##STR4## where m is an integer from 1 to 3, inclusive, n is an integer from 4 to 25, inclusive, A is alkyl, acyl or aroyl of 1-10 carbon atoms, B is alkyl, acyl or aroyl of 1-10 carbon atoms, and X is H, CH 3 or C 2 H 5 , (D) 1-16 parts by weight per hundred parts of matrix resin (A) of a crystallization promotor derived from (a) at least one source of carboxyl groups selected from the group consisting of hydrocarbon acids containing 7-54 carbon atoms and organic polymers having at least one carboxyl group attached thereto, and (b) at least one source of metal ions capable of reacting with the carboxyl groups of (a) selected from the group consisting of sodium and potassium ion sources, where the concentration of said metal in said matrix resin (A) is at least 0.01 weight percent, and (E) 0-80% by weight based on the total of components A, B, C, D and E of a material selected from the group consisting of reinforcing and filling materials.