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. 21, 2020
Filed:
Dec. 18, 2017
Applicant:
Covestro Deutschland Ag, Leverkusen, DE;
Inventors:
Thomas Knauf, Dormagen, DE;
Stefan Wershofen, Mönchengladbach, DE;
Klaus-Gerd Gruner, Duisburg, DE;
Volker Hartjes, Duisburg, DE;
Assignee:
Covestro Deutschland AG, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 209/78 (2006.01); C07C 209/54 (2006.01); C07C 209/60 (2006.01); C07C 211/48 (2006.01); C07C 211/50 (2006.01);
U.S. Cl.
CPC ...
C07C 209/78 (2013.01); C07C 209/54 (2013.01); C07C 209/60 (2013.01); C07C 211/48 (2013.01); C07C 211/50 (2013.01);
Abstract
The invention relates to a method for producing diamines and polyamines of the diphenylmethane series, by condensing aniline and formaldehyde followed by an acid-catalysed rearrangement at different production capacities. By adapting the temperatures in the acid-catalysed rearrangement step, the rearrangement reaction can be fully completed despite the change in dwell time inevitably associated with changed production capacity, with no undesired changes occurring in the product composition.