| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for stable continuous production of a polyester without using large-scale distillation equipment for the purification of a glycol component distilled out in a polycondensation reaction process, enabling the use of the glycol component as a raw material without the purification and achieving the reduction of an operation cost and the simplification of the facility. SOLUTION: A polyester is continuously produced from an aromatic dicarboxylic acid, its lower alkyl ester and a glycol component composed mainly of 1,4-butanediol. A part or total of the distillate composed mainly of 1,4- butanediol and recovered in the polycondensation reaction step is reused as a raw material for the polyester by adsorbing and removing the low-boiling materials in the distillate with a molecular sieve and subjecting the purified distillate to transesterification reaction or esterification reaction.
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