LATE ADDITION OF SUPPLEMENTAL ETHYLENE GLYCOL IN THE PREPARATION OF COPOLYESTERS

摘要

THE INVENTION IS DIRECTED TO A METHOD FOR MAKING COPOLYESTERS OF TEREPHTHALIC ACID AND A DIOL COMPONENT INCLUDING ETHYLENE GLYCOL AND INCLUDES THE STEPS OF ADDING TEREPHTHALIC ACID AND DIOL TO A FIRST ESTERIFICATION REACTOR AND THEN LATE ADDITION OF SUPPLEMENTAL ETHYLENE GLYCOL SUBSEQUENT TO THE FIRST ESTERIFICATION REACTOR BUT PRIOR TO A POINT WHERE THE ETHYLENE GLYCOL PARTIAL PRESSURE IS REDUCED BELOW ABOUT 300 TORR.