| 摘要 |
PROBLEM TO BE SOLVED: To provide a polycondensation catalyst for producing a polyester which comprises a metal component as a main component excluding an antimony, a germanium or a titanium compound, sustaining color tone, transparency and thermal stability, having a large polycondensation rate, low in production of foreign materials caused by the polycondensation catalyst and achieving both of quality and efficiency, and to provide a polyester giving a highly transparent molded article with reduced amount of foreign substance caused by the polycondensation catalyst, and to provide a method for producing them. SOLUTION: The invention relates to the polycondensation catalyst for polyester comprising at least a kind of compound selected from a group comprising aluminum compounds and at least a kind of compound selected from a group comprising phosphorus compounds, wherein an ethylene glycol solution is used which has the ratio of an integral of peaks appeared from -15 ppm to +30 ppm of a<SP>27</SP>Al-NMR spectrum to the integral of standard peaks is≥0.3. COPYRIGHT: (C)2006,JPO&NCIPI
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