摘要:
This invention is a polymer and a method of making heat resistant polyester which is characterized by reacting the polyester which consists of aromatic dicarboxylic acid and glycol with 2-6 carbons, with 0.1-5 weight % of the bifunctional epoxy compound which has one carbonyl group adjacent to the nitrogen atom and is expressed by the general formula ##STR1## (R is a divalent organic group) to keep the amount of end carboxyl group below 15 g equivalent/10.sup.6 g polymer.