Method for the production of polyester with mixed catalysts

US6358578B1 · kind B1 · utility

Assignee

• Zimmer, Inc. · US

Inventors

• Brigitta Otto · Lenzen (Elbe), DE
• Ulrich Thiele · Bruchköbel, DE
• Jens Schiebisch · Alzenau, DE

Key dates

• Filing date: Jun 12, 1998
• Grant date: Mar 19, 2002
• Expiry date: Jun 12, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/1352
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention comprises a method of producing polyester transesterification of at least a dicarboxylic acid dialkyl ester or esterification of at least a dicarboxylic acid with at least a diol and subsequent precondensation and polycondensation in the presence of the usual catalysts, whereby the polycondensation and optionally the esterification take place in the presence of an additional carbon containing co-catalyst, preferably activated charcoal with a specific surface area of more than 500 m2/g and an average grain size of less than 2 &mgr;m.