Inhibition of catalytically active impurities in polycarbonate by the melt transesterification process

US7250483B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Helmut-Werner Heuer · Krefeld, DE
• Melanie Mothrath · Mülheim an der Ruhr, DE
• Peter Snobl · Duisburg, DE
• Lothar Bunzel · Kempen, DE
• Thomas Pfingst · Tönisvorst, DE
• Marc Buts · Duffel, BE
• Lydia Simon · Shanghai, CN

Key dates

• Filing date: Jun 28, 2005
• Grant date: Jul 31, 2007
• Expiry date: Jun 28, 2025

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G64/406
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

An improvement to the melt transesterification process for the preparation of polycarbonate is disclosed. The improvement entails adding to the process between its medium viscosity reactor and a high viscosity reactor at least one bridged ester of organic sulphur-containing acid.