| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyester by which the deterioration of hue of a polyethylene terephthalate is suppressed, and the content of ether compounds such as diethylene glycol is reduced while improving the productivity to increase a polycondensation rate with not damaging the characteristics originally possessed by the polyethylene terephthalate at all. SOLUTION: The method for producing the polyethylene terephthalate including an ester-interchange reaction step and a melt polycondensation step includes carrying out the ester-interchange reaction step of dimethyl terephthalate and ethylene glycol by using at least one selected from titanium compounds (a) as an ester interchange catalyst, carrying out the melt polycondensation step by using a germanium compound and/or a titanium compound (b) as a polycondensation catalyst and further a phosphorous compound, and adding 1.0-18.0 mol% of a polycarboxylic acid based on the molar number of the dimethyl terephthalate after finishing the ester-interchange reaction step. COPYRIGHT: (C)2011,JPO&INPIT
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