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. 22, 2002
Filed:
May. 21, 2001
Applicant:
Inventors:
Peter Reuter, Mannheim, DE;
Guido Voit, Freinsheim, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
C07D / ;
Abstract
In a process for preparing phthalic anhydride by passing a gas stream comprising o-xylene, oxygen and sulfur dioxide at elevated temperature over a catalyst comprising heavy metals, the content of N-acyl compounds in the gas stream is restricted to less than 200 ppm, based on the weight of o-xylene.