Process for preparing diaryl carbonates and polycarbonates

US9175135B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Pieter Ooms · Krefeld, DE
• Andreas Bulan · Langenfeld, DE

Key dates

• Filing date: Mar 25, 2011
• Grant date: Nov 3, 2015
• Expiry date: Aug 30, 2031

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/10
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the continuous preparation of diaryl carbonates from phosgene and at least one monohydroxy compound (monophenol) in the presence of catalysts, and also the use thereof for preparing polycarbonates. The hydrogen chloride formed in the reaction is converted by thermal oxidation into chlorine, with the chlorine being recirculated to the preparation of phosgene. In particular, the process comprises utilization of the hydrogen chloride formed for the process for preparing diphenyl carbonate (DPC process).