Process for the production of solventless polycarbonate

US5191001A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Steffen Kuhlig · Krefeld, DE
• Ralf Pakull · Krefeld, DE
• Ulrich Grigo · New Martinsville, US
• Peter Tacke · Krefeld, DE
• Dieter Freitag · Krefeld, DE
• Wolfgang Alewelt · Krefeld, DE

Key dates

• Filing date: Oct 10, 1991
• Grant date: Mar 2, 1993
• Expiry date: Oct 10, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/448
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A three-step process for the production of solventless polycarbonate is disclosed. Accordingly, a mixture of two different oligocarbonates each prepared by the interfacial method, is prepared in the first process step. In a second step, the mixture is crystallized. The third step entails polycondensation. In an additional embodiment of the invention the first step uses a mixture of one oligocarbonate with a suitable monomer.