| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyester produced by using a condensation polymerization catalyst comprising a metal component except antimony and germanium as a main metal component of catalyst, to provide a method for continuous condensation polymerization of stable polyester, with which clogging of filter and nozzle by foreign matter during molding, transparency, yellowing, heat resistance, etc., are improved and to obtain a product thereof. SOLUTION: This method for continuous condensation polymerization of polyester comprises in a method for polyester production by continuous condensation polymerization using an oligomer obtained by direct esterification reaction and transesterification reaction between an aromatic and aliphatic dicarboxylic acid or its ester derivative and a diol or its ester derivative, a polyester condensation polymerization catalyst which is selected from at least an aluminum compound and a cobalt compound and satisfies conditions of a specific Al/Co molar ratio and Co concentration is added to the oligomer under conditions of a specific acid value of the oligomer. |
