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. 03, 2012
Filed:
Dec. 08, 2009
Tatsuyuki Kumano, Okayama, JP;
Kenji Nakaya, Okayama, JP;
Shinichi Nagao, Okayama, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A method of producing xylylenediamine by the hydrogenation of dicyanobenzene obtained by the ammoxidation of xylene in a high yield while prolonging the catalyst life. In the method, a molten dicyanobenzene from which compounds having a boiling point lower than that of dicyanobenzene have been removed but compounds having a boiling point higher than that of dicyanobenzene are not removed is dissolved in a solvent containing liquid ammonia. By this dissolution, at least part of dicyanobenzene polymers precipitates as insolubles. The precipitates are removed by a solid-liquid separation. By subjecting the resulting solution containing the dicyanobenzene polymers in a reduced amount to hydrogenation, xylylenediamine is produced in a high yield and the life time of hydrogenation catalyst is prolonged.