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. 09, 2019
Filed:
Mar. 30, 2017
Evonik Degussa Gmbh, Essen, DE;
Anne Rittsteiger, Olfen, DE;
Alexander Martin Rüfer, Recklinghausen, DE;
Guido Streukens, Wuppertal, DE;
Stephan Kohlstruk, Gladbeck, DE;
Matthias Orschel, Münster, DE;
Matthias Mendorf, Dortmund, DE;
Jorn Walscharts, Edegem, BE;
Axel Hengstermann, Senden, DE;
Anja Müller, Dortmund, DE;
Evonik Degussa GmbH, Essen, DE;
Abstract
A process for fine purification of isophoronediamine (IPDA), including producing IPDA by aminating hydrogenation of isophorone nitrile in the presence of at least ammonia, hydrogen, a a hydrogenation catalyst and optionally further additions to obtain a crude IPDA, and subjecting the crude IPDA to a fine purification via two vacuum distillation columns, wherein in the first vacuum distillation column the removal of any remaining relatively low-boiling byproducts is effected and in the second vacuum distillation column the IPDA is obtained in pure form as tops and thus separated from the organic residues, and wherein the first vacuum distillation column has vacuum distillation column has a partial condenser fitted to it.