摘要 |
PROBLEM TO BE SOLVED: To provide a method for continuously producing a polyester by reusing a glycol generated in the production process of the polyester, and capable of producing a high quality polyester economically and stably. SOLUTION: This method for continuously producing the polyester by mixing an aromatic dicarboxylic acid with the glycol in a slurry-preparation vessel to make slurry, feeding the slurry into an esterification reaction vessel to perform the esterification reaction, feeding the obtained low molecular weight polyester to a polycondensation reaction vessel to polycondensate, fractionating and removing a low boiling fraction consisting mainly of water from the glycol distilled off from the polyester production process by a distillation column installed in the polyester production process and circulating/reusing is provided by measuring water content in the recovered glycol on line and controlling the water content in the recovered glycol by changing the distillation column temperature through a feedback circuit based on the change of the water content. COPYRIGHT: (C)2007,JPO&INPIT
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