Method for producing polyesters with a reduced content of free acetaldehyde

US6559271B2 · kind B2 · utility

Assignee

• Inventa-Fischer GmbH & Co. KG · DE

Inventors

• Eckehart Schaaf · Teltow, DE
• Gerald Rafler · Potsdam, DE
• Rainer Hagen · Leverkusen, DE

Key dates

• Filing date: Sep 13, 2001
• Grant date: May 6, 2003
• Expiry date: Sep 13, 2021

Classification

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

Abstract

The invention relates to a method for producing polyesters with a reduced content of free acetaldehyde from terephthalic acid and ethylene glycol via a catalyzed polycondensation in the melt and also the use of this method. The method is based thereby on the usage of highly active polycondensation catalysts, on the deactivation of these catalysts by the addition of phosphorous-containing inhibitors and the addition of acetaldehyde-bonding substances. The entire polycondensation is thereby implemented at temperatures beneath 280° C.