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:
Mar. 13, 2007
Filed:
Mar. 25, 2005
Keisuke Sugita, Niihama, JP;
Masaru Kitamura, Niihama, JP;
Masahiro Hoshino, Niihama, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
Abstract
The invention provides a method for producing ε-caprolactam comprising the steps of: a reaction process which subjects cyclohexanone oxime to a Beckmann rearrangement reaction in the presence of a solid catalyst; and a catalyst regeneration process which regenerates the solid catalyst used in the reaction process by heat treatment under an atmosphere comprising an oxygen-containing gas, wherein the solid catalyst heat-treated in the catalyst regeneration process is used in the reaction process, the carbon contents in the solid catalyst in the reaction process and the catalyst regeneration process are maintained in a range of 0.5 to 2% by weight, and the nitrogen contents in the solid catalyst in the reaction process and the catalyst regeneration process are maintained in a range of 0.01 to 0.2% by weight. According to the invention, ε-caprolactam can be produced in a high production yield for a long period of time by enhancing persistence of the catalytic activity for producing ε-caprolactam.