Polyethylene terephthalate prodn. - by direct esterification of terephthalic acid with monoethylene glycol

摘要

The process is carried out discontinuously e.g. at 230-270 degrees C, pref. in the presence of an inhibitor for the formation of diethyleneglycol, such as a triethanolamine deriv. e.g. Ti aminotriethanolate. The pressure is reduced during the reaction e.g. from 6 kg/cm2 abs to 1 kg/cm2 abs to eliminate the water formed. Process offers a simple means for direct esterification of terephthalic acid with monoethylene glycol without the necessity for using large excesses of the glycol.