Polyester in melt preparation used in production of films, etc.

摘要

A process for preparing a polyester in the melt comprises: (1) reacting a diol with a diacid or diester to form a hydroxy-ester by (trans)esterification, and eliminating the majority of the diol (Glycol step); and (2) subjecting the product to polycondensation to achieve the required degree of polymerisation (Polycondensation step). An accelerator compound (I) which is liquid and dispersible in the reaction medium under the prevailing conditions of temperature and pressure is present in an amount of at least 0.25 wt. % of the theoretical weight of the polyester during at least part of the polycondensation step.