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:
Sep. 20, 2011
Filed:
Nov. 20, 2008
Pieter Ooms, Krefeld, DE;
Johann Rechner, Kempen, DE;
Matthias Böhm, Leverkusen, DE;
Andre Düx, Brühl, DE;
Kaspar Hallenberger, Leverkusen, DE;
Georg Ronge, Düsseldorf, DE;
Johan Vanden Eynde, Zwijnaarde, BE;
Pieter Ooms, Krefeld, DE;
Johann Rechner, Kempen, DE;
Matthias Böhm, Leverkusen, DE;
Andre Düx, Brühl, DE;
Kaspar Hallenberger, Leverkusen, DE;
Georg Ronge, Düsseldorf, DE;
Johan Vanden Eynde, Zwijnaarde, BE;
Bayer MaterialScience AG, Leverkusen, DE;
Abstract
Processes comprising: transesterifying a dialkyl carbonate and an aromatic hydroxyl compound in the presence of a transesterification catalyst to provide a diaryl carbonate product comprising the transesterification catalyst as an impurity; subjecting the diaryl carbonate product to distillation in a first distillation column having an upper part and a lower part, wherein the upper part comprises a rectifying section and the lower part comprises a stripping section; and withdrawing a first sidestream from the first distillation column, wherein the first sidestream comprises a purified diaryl carbonate.