Process for manufacturing linear fiber and film forming polyesters by polycondensation in the presence of a titanium alkoxide catalyst and a germanium compound

摘要

In the manufacture of linear film- and fibre-forming polyesters by reacting a dihydric alcohol with terephthalic acid or an ether-forming derivative thereof and polycondensing the resulting diol terephthalate, there is used as a catalyst, at least for the polycondensation reaction, a mixture of a titanium compound and a germanium compound (e.g. a mixture of titanium isopropoxide or n-butoxide and germanium tetraethoxide). If the polyester is prepared from an ester of terephthalic acid, calcium acetate may be used as an ester-interchange catalyst and this may be inactivated before the polycondensation reaction by the addition of triphhexyl phosphite. Titanium dioxide may be added to the polyesterification mixture. Specified dihydric alcohols are polymethylene glycols and 1:4-cyclohexane-dimethanol. A minor amount of the terephthalic acid may be replaced by imphthalic or sebacic acids. Specifications 775,316, 777,216, 793,111, 851,061 and 911,245 and U.S.A. Specifications 2,727,881 and 2,822,348 are referred to.