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 reaction zone, while simultaneously at higher temperatures than typical operation in order to lower incorporation of DEG into the final polymer.

Abstract: Process for preparing copolyesters by introducing TPA, EG, and CHDM at an EG:TPA molar ratio of 2.3:1 to 2.7:1 into a reaction zone; reacting TPA with EG and CHDM at a temperature of at least 250° C. and pressure of up to 40 psi to form a first esterification product; passing the first esterification product to a reaction zone; esterifying the first esterification product at a temperature of at least 250° C. and pressure of up to 20 psi to form a second esterification product, passing the second esterification product to a reaction zone; polycondensing the second esterification product in the presence of a catalyst to form a prepolymerization product; passing the prepolymerization product to one or more reaction zones; and polycondensing the prepolymerization product in the presence of the catalyst to form a copolyester comprising 1.0 wt % or less of DEG, without requiring the use of DEG-suppressing additives.

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.

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 reaction zone, while simultaneously at higher temperatures than typical operation in order to lower incorporation of DEG into the final polymer.