Abstract: Disclosed is a method for producing a titanium containing catalyst, wherein the catalyst includes one or more titanium alpha-hydroxy carboxylate species, e.g., titanium citrate, and one or more titanium oxide species, e.g., TiOx, wherein x is greater than 0 and less than or equal to 2, wherein the sum of all of the above titanium oxide species relative to the sum of all titanium alpha-hydroxy carboxylate species in the titanium containing catalyst is greater than 0 but less than 1.00 mol.-%. The method of production involves, for example, reacting tetraisopropyl orthotitanate with an aqueous solution of citric acid, and removing the byproduct of 2-propanol by distillation. Also disclosed is a method for the production of polyesters by the use of the catalyst.

Abstract: The present invention is directed to a method for the production of a titanium containing catalyst, wherein a titanium-(IV)-alkoxide of high purity is reacted with an alpha-hydroxy carboxylic acid. Furthermore the invention concerns a titanium containing catalyst allowing for the production of high viscosity polyesters with high thermal stability. In addition, the invention is directed to a method for the production of polyesters and polyesters themselves.