Eastman Chemical Company
COPOLYESTER FROM TEREPHTHALIC ACID CONTAINING LOW DIETHYLENE GLYCOL

Abstract:

Copolyesters made from the direct esterification of terephthalic acid with diols including ethylene glycol, but which contain low diethylene glycol (DEG) content, and processes for making the copolyesters. The copolyesters are characterized by comprising 1.0 wt % or less of DEG without requiring the use of DEG-suppressing additives. The processes are characterized by features including operating at lower pressures and lower EG:TPA feed mole ratios in the first esterification zone, while simultaneously at higher temperatures than typical operation in order to lower incorporation of DEG into the final polymer.