| 摘要 |
<p>An improved process for preparing high molecular weight polyester polymers, such as poly(butylene terephthalate), an alkylene glycol and a di- or tricarboxylic acid by first preparing a pre-polymer in the form of uniform solid particles having an intrinsic viscosity of from 0.1 to about 0.3 dL/gm and a chemical composition which contains greater than a 1% stoichiometric excess of the alkylene glycol above the amount required to produce a high molecular weight polymer, and polymerizing the pre-polymer in the solid state.</p> |
