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:
Oct. 12, 1999
Filed:
Apr. 01, 1997
Applicant:
Inventors:
Hans-Josef Buysch, Krefeld, DE;
Carsten Hesse, Krefeld, DE;
Johann Rechner, Kempen, DE;
Hans-Peter Wirges, Krefeld, DE;
Assignee:
Bayer AG, , DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01J / ; B01J / ; B01J / ; C07C / ;
U.S. Cl.
CPC ...
502 33 ; 502 20 ; 502 24 ; 502 29 ; 558270 ; 558274 ;
Abstract
Catalyst systems with a content of a platinum-group-metal catalyst, a co-catalyst, a quaternary salt and a base for the oxidative carbonylation of aromatic hydroxy compounds to the corresponding diaryl carbonates are according to the invention obtained as a mother liquor by suspension crystallization and can be returned into the carbonylation reaction or worked up to valuable materials. The crystallizate, which consists predominantly of diaryl carbonate and the parent aromatic hydroxy compound, is worked up to pure diaryl carbonate and pure hydroxy compound.