| 摘要 |
PURPOSE:To produce a polyester while advantageously recirculating a Ge compound catalyst, by subjecting a distillate containing the Ge compound catalyst to a specified treatment and using the treated distillate in the reaction in the production of a polyester. CONSTITUTION:A process for producing a polyester by esterifying or transesterifying terephthalic acid or dimethyl terephthalate with ethylene glycol and polycondensing the product in the presence of a germanium compound catalyst is performed as follows. Namely, in order to reuse a distillate containing the germanium compound catalyst, which is distilled during the polycondensation, as ethylene glycol in the esterification or the transesterification, insoluble components are removed from the distillate so that their concentration may be decreased to 1wt% or below, and this distillate is treated with an adsorbent and fed to the reaction system. Examples of the germanium compounds which can be used include germanium dioxide, germanium chloride and germanium butoxide.
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