Process for the preparation of polycarbonates

US7071284B2 · kind B2 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Hermann Kauth · Krefeld, DE
• Christian Kords · Krefeld, DE
• Jürgen Heuser · Krefeld, DE

Key dates

• Filing date: Jan 5, 2004
• Grant date: Jul 4, 2006
• Expiry date: Jan 5, 2024

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G64/14
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

An improvement in the continuous two-phase interfacial condensation process for preparing polycarbonate is disclosed. In the process that entails at least one diphenol, phosgene, at least one chain terminator, and optionally branching agents and is carried out in the presence of a catalyst the improvement comprising maintaining the concentration of the catalyst at a level of at least 0.012 mol per mol of diphenol.