Patent ID: 7501373

Claim:
A method of producing a polyester comprising: contacting an acid component and an alcohol component in the presence of a catalyst, the polyester having a glycol component consisting mainly of at least one of ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,4-cyclohexane dimethanol, the catalyst comprising at least one metal-containing component having substantially no catalytic activity for a polyester polymerization, selected from the group consisting of metals and metal compounds, wherein said metal-containing component comprises no antimony or germanium; and an organic compound component having substantially no catalytic activity for a polyester polymerization, wherein said organic compound component is at least one compound containing at least one moiety represented by Formula 1: Ar—O— (Formula 1) wherein Ar represents an aryl group, wherein the aryl group is not a phenyl group (C 6 H 5 ), wherein the metal containing component and the organic compound component are added separately, wherein the activity parameter of the catalyst is less than 2 times the activity parameter observed when using antimony trioxide as a catalyst in the polymerization of polyethylene terephthalate, wherein the activity parameter of the catalyst, AP, fulfills the formula AP<2T wherein AP is the amount of time required for a polymerization using the catalyst conducted at 275° C. under reduced pressure of 0.1 Torr to obtain a polyethylene terephthalate whose intrinsic viscosity is 0.5 dl/g, and wherein T is an AP observed when using antimony trioxide as a catalyst at a level of 0.05 mol % as antimony atom based on an acid component in a resultant polyethylene terephthalate.