| 摘要 |
<p>In a process for the continuous preparation of polybutylene terephthalate from terephthalic acid and 1,4-butanediol comprising:a) direct esterification of terephthalic acid with 1,4-butanediol in a reactor cascade comprising at least two reactors,b) precondensation of the esterification product obtained in stage a), andc) polycondensation of the precondensate obtained in stage b),the reaction pressure decreases and the temperature does not increase along the reactor cascade in stage a).</p> |
