| 摘要 |
To provide a catalyst for production of a polyester, a process for producing a polyester using the catalyst and a titanium-containing polyethylene terephthalate having excellent characteristics. A catalyst for production of a polyester, characterized by comprising at least (1) a Group 4A compound (hereinafter referred to as compound (1)), (2) a compound of at least one element selected from the group consisting of magnesium, calcium and zinc (hereinafter referred to as compound (2)) and an oxygen-containing organic solvent. A process for producing a polyester using this catalyst. A titanium-containing polyethylene terephthalate, having characteristics represented by the following (A), (B) and (C): (A) titanium K absorption edge: the peak intensity ratio R defined by R=A/B exceeds 0.2, where A is the intensity of a peak having the maximum intensity among K absorption pre-edge peaks, and B is the maximum peak intensity of K absorption post-edge peaks in a XANES spectrum obtained by normalizing a XAFS spectrum; (B) the amount of carboxyl end groups is less than 35 eq/ton; and (C) the intrinsic viscosity is at least 0.5 dl/g.
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