The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 12, 2003
Filed:
Jun. 15, 2001
Carsten Hesse, Tönisvorst, DE;
Ursula Jansen, Neuss, DE;
Johann Rechner, Kempen, DE;
Claus-Peter Reisinger, Krefeld, DE;
Rob Eek, Bergen op Zoom, NL;
Kaspar Hallenberger, Leverkusen, DE;
Martin Friedrich, Köln, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A process for the work up of a reaction mixture obtained from the preparation of diaryl carbonate by direct carbonylation of aromatic hydroxy compounds is disclosed. The process entails obtaining a reaction mixture that contains diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, separating the mixture in a distillation apparatus having only one theoretical separation stage into a liquid phase and a gas phase and recycling the liquid phase without further work up to the reaction step of the direct carbonylation.