| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyester in which an oligomer can efficiently be removed to the outside of a system without causing the clogging of piping with the oligomer distilled at a polycondensation step, and thus the polyester can be produced in good productivity. SOLUTION: The distillate is removed after dissolving the oligomer by adding the same alkylene glycol as the alkylene glycol used as a raw material to the distillate generated at the polycondensation step so that the concentration of the oligomer becomes≤3 mass%, when producing the polyester from a dicarboxylic acid component comprising an aromatic dicarboxylic acid and a 6-12C aliphatic dicarboxylic acid as main components, and the 2-8C alkylene glycol through an esterification step and the polycondensation step. COPYRIGHT: (C)2009,JPO&INPIT
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