POLYESTER POLYMERIZATION CATALYST AND POLYESTER PRODUCED BY USING THE SAME AND METHOD FOR PRODUCING POLYESTER

摘要

PROBLEM TO BE SOLVED: To provide a polyester polymerization catalyst comprising components other than an antimony compound and a germanium compound as principal components of the catalyst and having excellent catalyst activity, a polyester produced by using the catalyst and a method for producing the polyester. SOLUTION: This polyester polymerization catalyst comprises at least two kinds of compounds as constituent components and is characterized in that a spectral change is observed by mixing the components. The polyester is produced by using the polyester polymerization catalyst and the method for producing the polyester comprises using the polyester polymerization catalyst.