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:
May. 27, 2003
Filed:
Feb. 19, 2002
Applicant:
Inventors:
Werner Peschel, Freinsheim, DE;
Bernd Bessling, Grünstadt, DE;
Peter Reuter, Mannheim, DE;
Peter Michael Lorz, Wachenheim, DE;
Bernhard Ulrich, Bockenheim, DE;
Jean Werner Knab, Limburgerhof, DE;
Matthias Kummer, Weisenheim, DE;
Thomas Rühl, Frankenthal, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
C07D / ;
Abstract
On-spec phthalic anhydride is prepared by distillative purification of crude phthalic anhydride by a process in which crude phthalic anhydride is fed to a distillation column which is operated at reduced pressure, the low boilers are removed at the top or in the vicinity of the top of the distillation column and the on-spec phthalic anhydride is removed from the column via a side take-off.