AROMATIC POLYESTER RESIN AND METHOD OF PRODUCING THE SAME

摘要

Provided is an aromatic polyester resin which contains only a small amount of metallic impurities, exhibits relatively excellent thermal properties and mechanical properties and has a high molecular weight. Also provided is a method of producing an aromatic polyester resin having a high molecular weight through a process with low environmental burden wherein a hydrolase is employed as a polymerization catalyst. An aromatic polyester resin, which contains a low amount of metallic impurities, exhibits relatively excellent thermal properties and mechanical properties and has a high molecular weight, can be obtained by using a dicarboxylic acid component comprising terephthalic acid, naphthalenedicarboxylic acid or a derivative thereof and a diol component while selecting the kinds of the monomer components employed and the composition ratio thereof so that a polyester resin can be synthesized under such environment as not impairing the catalytic activity of a hydrolase, using as a polymerization catalyst a hydrolase capable of showing a sufficient catalytic activity for these components, and controlling the temperature conditions during the polycondensation or preliminarily preparing an ester oligomer and then using the same in polycondensation.