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:
Apr. 19, 2005
Filed:
Mar. 01, 2004
Kazuhiko Amakawa, Niigata, JP;
Kazushi Gouroku, Niigata, JP;
Kazuhiko Amakawa, Niigata, JP;
Kazushi Gouroku, Niigata, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
In the method of the present invention, xylylenediamine is produced by a two-stage hydrogenation of a dicyanobenzene compound. In a first stage (a), the hydrogenation is performed until a conversion of nitrile groups reaches 90 mol % or higher and less than 99.9 mol %. In a second stage (b), the hydrogenation is further continued at temperatures 10° C. or more higher than in the step (a) until the conversion of nitrile groups reaches a level which is higher than that attained in the step (a) and equal to 99.5 mol % or more. In the present invention, a highly pure xylylenediamine containing a minimized amount of cyanobenzylamine is efficiently produced in a simple manner without needing a specific purification, and also without deteriorating the use efficiency of the catalyst while reducing the amount of the dicyanobenzene compound remaining not reacted and the generation of the intermediate cyanobenzylamine.