Process for preparing polyesters

摘要

In a process for the preparation of high molecular weight linear polyesters of terephthalic acid which comprises partially esterifying terephthalic acid with an alkylene glycol under direct esterification conditions and then further esterifying and polycondensing the partially esterified product, the molecular weight distribution of the polyester is narrowed by correlating the carboxyl conversion with the reacted glycol to terephthalic acid mol ratio in various steps of a multistep process.