POLYESTER SOLID PHASE POLYMERIZATION CATALYST FOR LOW ACETALDEHYDE GENERATING RESINS

Abstract

This invention discloses a process for producing a polyester resin having a low acetaldehyde generation rate comprised of the steps of polycondensing the polyester resin in the presence of tin and antimony; wherein the tin is present within the range of 50 to 110 ppm of the polyester resin and the antimony is present from 105 ppm to 265 ppm of the polyester resin, and solid phase polymerizing the polyester resin for sufficient time so as to increase the intrinsic viscosity of the polyester resin by at least 0.15 dl/g.

Description

Claims

1. A method for producing a polyester resin having a low acetaldehyde generation rate comprised of the steps of polycondensing the polyester resin in the presence of tin and antimony; wherein the tin is present within the range of 30 to 110 ppm of the polyester resin and the antimony is present from 95 ppm to 300 ppm of the polyester resin,andsolid phase polymerizing the polyester resin for sufficient time so as to increase the intrinsic viscosity of the polyester resin by at least 0.15 dl/g.

2. A catalyst composition for producing a low acetaldehyde generation polyester resin using a solid state process, wherein said catalyst composition comprises tin and antimony; wherein the tin is present within the range of 30 to 110 ppm of the polyester resin and the antimony is present from 95 ppm to 300 ppm of the polyester resin.

3. The catalyst of claim 2, wherein the catalyst further comprises a molar equivalent amount of cobalt and phosphorous, wherein the cobalt is present at less than 15 ppm of the polyester resin.