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:
Dec. 10, 1996
Filed:
Dec. 22, 1994
Applicant:
Inventors:
Assignee:
Degussa Aktiengesellschaft, Frankfurt, DE;
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
564446 ; 564448 ; 564455 ;
Abstract
A method of controlling the cis/trans isomer ratio in the preparation of isophoronediamine by the aminating hydrogenation of isophoronenitrile in the presence of ammonia, H.sub.2 and a catalyst. The reaction takes place in two temperature steps, initially at 10.degree. to 90.degree. C. and then at above 90.degree. to 150.degree. C. with a temperature difference of at least 30.degree. C. between the two steps, the contact time being shorter in the first step than in the second. The cis/trans ratio is increased by lowering the temperature of the first step.