method for preparing a katalysatoroplossing consisting of a solution of germaniumdioxyde in ethylene glycol.method for preparing polyethylene terephthalate in presence of a katalysatoroplossing thus prepared and formed products which are obtained from the vervaa terephthalaterule.

摘要

In the manufacture of polyesters by polycondensing a glycol terephthalate, the polycondensation catalyst used is a preformed solution made in a separate step by heating germanium dioxide and a glycol at 210 DEG to 300 DEG C. and under a pressure of 1.5 to 15 atmospheres absolute. Specified glycols are ethylene glycol and 1:4-di-(hydroxymethyl)-cyclohexane. The glycol terephthalate monomer is preferably made by a transesterification reaction using as a catalyst a compound of an alkali metal, an alkaline earth metal, Zn, Cd, Mn, Pr, Ce or La. Examples describe the manufacture of polyethylene terephthalate from dimethyl terephthalate and ethylene glycol.