Method for producing a copolymerized polyester resin

摘要

A method for producing a copolymerized polyester resin, which comprises subjecting a dicarboxylic acid component containing terephthalic acid or its ester derivative as the main component and a phenylene dioxydiacetic acid as a copolymerizable component, and a diol component containing ethylene glycol as the main component, to polycondensation through an esterification reaction or a transesterification reaction, wherein the phenylene dioxydiacetic acid is added to the reaction system in the form of a solution dissolved in the diol component.