| abstract |
(57) [Summary] [PROBLEMS] To provide a method for producing polyethylene terephthalate which can be efficiently precrystallized even with copolymerized polyethylene terephthalate. In a method for producing polyethylene terephthalate including a liquid-phase polycondensation reaction step, a pre-crystallization step, and a solid-phase polycondensation reaction step, the pre-crystallization step (A) is carried out while stirring a PET chip with Tg or more, and Temperature below 150 ° C (T Step ( 1 ) of heating to partially crystallize PET, Heating the PET chip to a temperature in the range from (T bm −40 ° C.) to T bm to crystallize the PET chip until the crystallinity of PET becomes at least 30% (where T bm is Endothermic onset temperature of sub-peak among endothermic peaks observed when the temperature is raised at a rate of 10 ° C./min using DSC), (C) a step of heating and raising the temperature of the PET chip to the solid phase polycondensation temperature while stirring. |