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:
Feb. 17, 1976
Filed:
Oct. 05, 1973
Applicant:
Inventors:
John D Gardner, Richmond, CA (US);
John F Manning, Albany, CA (US);
Assignee:
Chevron Research Company, San Francisco, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
2603 / ; 2603467 ;
Abstract
A method for obtaining purified polycarboxylic anhydrides of good color stability which comprises combining and contacting a metal halide and P.sub.2 O.sub.5 or a perborate with the crude anhydride before final distillation of the crude anhydride. Preferred metal halides are alkaline earth and transition metal halides, with magnesium, calcium and iron chlorides being particularly preferred. The method is especially advantageously applied to maleic anhydride purification, especially maleic anhydride produced by butane oxidation.