Patent ID: 6986864

Claim:
A polyester composition comprising: I. about 70 to about 97.5 weight percent of a thermoplastic polyester comprising poly(ethylene terephthalate) having an intrinsic viscosity of about 0.55 to 1.1 dL/g, measured at 25° C. in a solvent consisting of 60 weight percent phenol and 40 weight percent tetrachloroethane; II. about 2 to about 25 weight percent of an impact modifying polymer comprising one or more ethylene/methyl acrylate/glycidyl methacrylate terpolymers containing about 20 to 35 weight percent methyl acrylate residues and about 2 to 10 weight percent glycidyl methacrylate residues and mixtures of the terpolymers with up to 50 weight percent of an ethylene/methyl acrylate copolymer containing about 20 to 35 weight percent methyl acrylate residues; and III. about 0.5 to about 5 weight percent of a block copolymer of poly(tetramethylene terephthalate) and poly(oxytetramethylene)diol wherein (i) the poly(oxytetramethylene)diol residue segment has an average molecular weight of about 800 to about 2000 gram per mole, (ii) the poly(oxytetramethylene)diol residue segment constitute about 10 to 80 weight percent of the block copolymers, and (iii) the block copolymer has an intrinsic viscosity from about 0.25 to about 1.2 dL/g, measured at 25° C. in a solvent consisting of 60 weight percent phenol and 40 weight percent tetrachloroethane; wherein the weight percentages of I, II and III are based on the total weight of components I, II and III.