Process for preparing diaryl carbonates and the polycarbonates obtainable therefrom

US5739258A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gottfried Zaby · Leverkusen, DE
• Hans-Josef Buysch · Krefeld, DE
• Steffen Kuhling · Meerbusch, DE
• Carsten Hesse · Krefeld, DE
• Johann Rechner · Krefeld, DE

Key dates

• Filing date: Mar 3, 1997
• Grant date: Apr 14, 1998
• Expiry date: Mar 3, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C68/01
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for preparing a diaryl carbonate by oxidative carbonylation of the basic aromatic hydroxy compound, in which the aromatic hydroxy compound is the one which is eliminated during melt polycondensation of this diaryl carbonate with a bisphenol. Accordingly the invention also relates to the preparation of polycarbonates by melt polycondensation of diaryl carbonates with bisphenols in which the aromatic hydroxy compounds which is eliminated is used again to prepare the diaryl carbonate. In the event that the aromatic hydroxy compound eliminated is also the basic unit in the bisphenol used, proportions of it may be used to prepare both the diaryl carbonate and the bisphenol.