| 摘要 |
PROBLEM TO BE SOLVED: To provide a polymerization catalyst for a polyester excellent in moldability and processability, in which problems of deterioration of color tone, strain on spinneret, increase in filtrating pressure, yarn breakage, or the like, are solved in production of molded products such as those for fibers, films and bottles, and to provide a method for producing the polyester by using the catalyst. SOLUTION: In this method for producing the polyester by polycondensing a product obtained by carrying out esterification reaction of an aromatic dicarboxylic acid or an ester-formed derivative thereof with a diol or an ester- formed derivative thereof, the polymerization catalyst for the polyester is characterized by including a titanium compound in which a main metal element is titanium, a phosphorus compound and a nitrogen-containing compound having >=2 carboxylic acids in one molecule. The method for producing the polyester comprises using the above catalyst.
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