Process for the preparation of polyesters and copolyesters

US5789528A · kind A · utility

Assignee

• AKZO NOBEL N.V. · NL

Inventors

• Michael Martl · Frankfurt, DE
• Thomas Mezger · Zell am Harmersbach, DE
• Bernard Kuhn · Reichelsheim, DE
• Gerriet Oberlein · Velbert, DE
• Klaus Haferland · Wuppertal, DE
• Bertram Boehringer · Wuppertal, DE
• Ulrich Berger · Trochtelfingen, DE

Key dates

• Filing date: Mar 13, 1997
• Grant date: Aug 4, 1998
• Expiry date: Mar 13, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/85
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The preparation of polyesters and copolyesters, titanium dioxide precipitates and/or titanium dioxide/silicon dioxide coprecipitates having a composition of TiO.sub.2 :SiO.sub.2 >90:10 mol/mol and/or titanium dioxide/zirconium dioxide coprecipitates having a composition of TiO.sub.2 :ZrO.sub.2 >95:5 mol/mol, which have been obtained by hydrolytic precipitation of the corresponding metal alcoholates formed from mono- or polyhydric alcohols, are proposed as polycondensation catalysts. They offer increased safety for the ecosystem and have a higher catalytic activity than Sb.sub.2 O.sub.3, so that the preferred amount used is only 10 to 100 ppm, based on the esters or oligoesters to be subjected to polycondensation. Their storage stability is good if the catalysts have a water content of from 0 to about 15 weight percent, preferably from 0 to about 5 weight percent based upon the hydrated precipitate or coprecipitate, as determined by Karl Fischer titration.