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. 12, 2002
Filed:
Jan. 14, 2000
Daicel Chemical Industries, Ltd., Osaka, JP;
Abstract
&bgr;-isophorone is formed by isomerizing &agr;-isophorone in the presence of an isomerizing catalyst (an aliphatic C polycarboxylic acid) in an isomerizing-reaction unit . The &bgr;-isophorone thus formed is oxidized with oxygen in an inert solvent in the presence of an oxidizing catalyst (a complex salt of a transition metal and an N,N′-disalicylidenediamine) in an oxidizing-reaction unit , thereby forming ketoisophorone. After removing a low-boiling point component, which is an impurity (non-conjugated cyclic ketone), from the reaction mixture using a distilling unit , a high-boiling component (oxidizing catalyst) is separated in a distilling unit , and then ketoisophorone is separated from the solvent in the separation unit . Thereafter, the solvent containing 0 to 5,000 ppm (weight basis) of the impurities and substantially free from ketoisophorone is recycled to the oxidizing reaction through a recycling line . According to the present invention, the combination of the isomerizing reaction and the oxidizing reaction makes it possible to produce ketoisophorone from &agr;-isophorone while maintaining the activity of the oxydizing catalyst.