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:
Jul. 27, 1999
Filed:
Oct. 27, 1997
Masahiro Chikamori, Ibo-gun, JP;
Ikuo Takahashi, Kobe, JP;
Daicel Chemical Industries Ltd., Osaka, JP;
Abstract
Highly purified 3,5,5-trimethylcyclohexa-3-en-1-one is produced with a high production efficiency by inhibiting thermal decomposition of an isomerization catalyst. The method comprises isomerizing 3,5,5-tri-methylcyclohexa-2-en-1-one (.alpha.-isophorone) in the presence of an isomerization catalyst under reduced pressure at a reaction temperature of 90.degree. C. to 205.degree. C., and simultaneously distilling the reaction product, thereby inhibiting thermal decomposition of the isomerization catalyst. This method provides the isomerized product at a high level of the unit-time production for a long period, and prevents contamination caused by the decomposed product of the isomerization catalyst.