Poly(ethylene)terephthalate having a slow crystallisation rate and polycondensation catalysts for its preparation

摘要

The preparation of poly(ethylene)terephthalate having a slow crystallisation rate suitable among other things for the production of textile fibre and a class of catalysts for use in the polycondensation stage in synthesis of the said poly(ethylene)terephthalate comprising aromatic sulphonic acids in a mixture with antimony or germanium and titanium derivatives is described.