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:
Jun. 07, 1994
Filed:
Nov. 09, 1992
Applicant:
Inventors:
Joon T Kwon, Freehold, NJ (US);
Joseph W Stanecki, Boonton, NJ (US);
Assignee:
ABB Lummus Crest Inc., Bloomfield, NJ (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549262 ; 203-8 ; 203-9 ;
Abstract
In the production of maleic anhydride, a crude maleic anhydride is produced which contains acrylic acid and other by-products. The crude maleic anhydride is dissolved in a solvent and the acrylic acid is distilled off. To avoid the polymerization of the acrylic acid, an inhibitor of phenothiazine is added to the distillation process.