POLYMERIZATION CATALYST FOR PREPARING POLYESTERS, PREPARATION OF POLYETHYLENE TEREPHTHALATE AND USE OF POLYMERIZATION CATALYST

摘要

The invention relates to a polymerization catalyst for preparing polyesters. The catalyst contains aluminium hydroxide and/or aluminium acetate as a first component and at least one phosphoric or phosphonic ester as a second component. The inventionalso relates to a polymerization process for preparing polyethylene terephthalate from dimethyl terephthalate and ethylene glycol by transesterification and polycondensation respectively. The invention futher relates to the use of aluminium hydroxide and/or aluminium acetate in combination with at least one phosphoric or phosphonic ester as polymerization catalyst when preparing polyesters by polycondensation or transesterification.