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:
Aug. 09, 2005
Filed:
Aug. 28, 2003
Applicants:
Hiroto Kasuga, Himeji, JP;
Eiichi Shiraishi, Himeji, JP;
Inventors:
Hiroto Kasuga, Himeji, JP;
Eiichi Shiraishi, Himeji, JP;
Assignee:
Sumitomo Chemical Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C051/16 ;
U.S. Cl.
CPC ...
Abstract
This invention provides a method of reactivating a catalyst for methacrylic acid production, which catalyst is used in production of methacrylic acid through vapor-phase oxidation of methacrolein or vapor-phase oxidative dehydrogenation of isobutyric acid, contains P and Mo, and exhibits reduced activity. The process comprises treating the catalyst, whose activity level has dropped (deteriorated catalyst), with a gas containing a nitrogen-containing heterocyclic compound (e.g., pyridine, piperidine, piperazine, quinoline).