Process for the preparation of polycarbonates

US7705107B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Hermann Kauth · Krefeld, DE
• Wolfgang Ebert · Krefeld, DE
• Wilfried Haese · Rheydt, DE
• Helmut Einberger · Odenthal, DE
• Alexander Meyer · Mülheim an der Ruhr, DE
• Andreas Frankenau · Kempen, DE
• Uli Franz · Solingen, DE
• Christian Eh · Bang Phra, TH
• Stefaan De Vos · Rayong, TH
• Bert Ruytinx · Halen, BE

Key dates

• Filing date: Dec 20, 2005
• Grant date: Apr 27, 2010
• Expiry date: Sep 26, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31507
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

An improvement to the phase interface process of preparing aromatic polycarbonate is disclosed. The process is characterized in that the phosgenation is carried out at 0 to 40° C., and in that the temperature of the reaction mixture at the time of addition of the catalyst at 10 to 40° C., and in that the molar ratio of aromatic dihydroxy compounds to phosgene at 1:1.05 to 1:1.20. The polycarbonate thus produced is characterized in its low content of carbamates, making it particularly suitable for the preparation of optical storage media.