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:
Nov. 06, 2012
Filed:
Oct. 03, 2011
Christoph Gürtler, Köln, DE;
Thomas Ernst Müller, München, DE;
Pieter Ooms, Krefeld, DE;
Friedhelm Risse, Köln, DE;
Johann Rechner, Kempen, DE;
Franco Doro, Aachen, DE;
Angelina Prokofieva, Aachen, DE;
Christoph Gürtler, Köln, DE;
Thomas Ernst Müller, München, DE;
Pieter Ooms, Krefeld, DE;
Friedhelm Risse, Köln, DE;
Johann Rechner, Kempen, DE;
Franco Doro, Aachen, DE;
Angelina Prokofieva, Aachen, DE;
Bayer Intellectual Property GmbH, Monheim, DE;
Abstract
The present invention relates to a process for continuously preparing diaryl carbonates from dialkyl carbonates and at least one monohydroxyl compound in the presence of catalysts, and to the use thereof for preparation of polycarbonates. The alkylene glycol obtained in the preparation of the dialkyl carbonate used is recycled by oxidative carbonylation with carbon monoxide in the presence of a catalyst to give the cyclic alkylene carbonate which is in turn converted to the dialkyl carbonate. More particularly, the process utilizes the alkylene glycol obtained for the diphenyl carbonate preparation process (DPC process).