Production and use of polyester carbonates

US6646099B2 · kind B2 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Silke Kratschmer · Krefeld, DE
• Lothar Bunzel · Kempen, DE
• Wolfgang Alewelt · Krefeld, DE
• Renate Wilms · Krefeld, DE

Key dates

• Filing date: Jun 26, 2002
• Grant date: Nov 11, 2003
• Expiry date: Jun 26, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/64
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A transesterification process for producing polyester is disclosed. In a first stage of the process there is heated, in an inert gas atmosphere, a first mixture containing at least one dihydroxy compound and at least one diaryl carbonate to form an oligocondensate. In a second stage there is added to the oligocondensate at least one dicarboxylic acid to form a second mixture. The second mixture is heated to a temperature not higher than 290° C. in the presence of a quaternary onium compound as catalyst to form polyester carbonate. Hydroxyaryl formed throughout the process is distilled-off under reduced pressure.