| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a polyester suited in molding which has good color tone and transparency and reduced mold staining then using a cyclic trimer. SOLUTION: The polyester which has terephthalic acid and ethylene glycol as the major components and an intrinsic viscosity of 0.65-1.0 and a content of a cyclic trimer of <=0.4 mass % can be obtained by solid polymerization of a prepolymer having an intrinsic viscosity of 0.50-0.70 and containing 1×10-4 mol to 7×10-4 mol, based on 1 mol total acid component of the polyester, of a phosphorus element and 5×10-5 mol to 2×10-4 mol, based on 1 mol total acid component of the polyester, of a germanium element, respectively, a content of carboxyl terminal groups of 10-30 equivalents/106 g, and a content of hydroxyl terminal groups of 80-120 equivalents/106 g.
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