Continuous production of polycarbonates

US5235026A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Claus Wulff · Krefeld, DE
• Hermann Kauth · Krefeld, DE
• Gunther Weymans · Leverkusen, DE
• Zoltan Kricsfalussy · Leverkusen, DE
• Wolfgang Alewelt · Krefeld, DE
• Jürgen Heuser · Krefeld, DE

Key dates

• Filing date: May 29, 1992
• Grant date: Aug 10, 1993
• Expiry date: May 29, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G64/24
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

An improvement to the continuous process for the production of polycarbonates by interphase polycondensation is described. Accordingly, the organic phase and the aqueous phase are combined in a tube, forming chlorocarbonic acid ester and further alkali hydroxide is added at, or shortly after, the maximum concentration of said ester is reached. The resulting emulsion is then changed to an oil-in-water emulsion which is then separated and worked up in known manner.