Patent ID: 7608652

Claim:
Process for the production of polyethylene terephthalate from terephthalic acid and ethylene glycol, comprising the steps of: (a) preparing a catalyst composition consisting of an antimony compound, being present such that the elemental antimony content is in a range of about 100 to about 140 ppm, and a zinc compound, being present such that the elemental zinc content is in a range of about 80 to about 140 ppm, wherein the ppm amounts by weight are based on the theoretical yield of polyethylene terephthalate; (b) placing the catalyst composition, the terephthalic acid and the ethylene glycol in a vessel; and (c) reacting the terephthalic acid and the ethylene glycol in an esterification step and a polycondensation step to obtain polyethylene terephthalate.