METHOD OF PREPARING POLYETHYLENE TEREPHTHALATE Russian patent published in 1997 - IPC

FIELD: manufacture of bottles, films and synthetic fiber having viscosity index of 74-80. SUBSTANCE: process for preparing polyethylene terephthalate comprises transesterification of dimethyl terephthalate and ethylene glycol in the presence of manganese acetate and polycondensation of the resulting product in the presence of mixed catalyst of manganese acetate and sodium germanate, on completion of transesterification, 90-99% manganese acetate is blocked by phosphorous acid at P/Mn molar ratio of more than 1. This catalyst is added prior to polycondensation stage. Sodium germanate is added in amount of 60-75 ppm Ge, and polycondensation is carried out. Sodium germanate is added in the form of solution in ethylene glycol. Mixed catalyst comprises 90 ppm Mn and 60-75 ppm Ge. EFFECT: more efficient preparation method. 3 cl, 3 tbl