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:
Nov. 13, 2018
Filed:
Jun. 22, 2015
Applicant:
Covestro Deutschland Ag, Leverkusen, DE;
Inventors:
Thomas Knauf, Dormagen, DE;
Stefan Wershofen, Monchengladbach, 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);
U.S. Cl.
CPC ...
C07C 209/78 (2013.01); C07C 209/78 (2013.01); C07C 211/50 (2013.01);
Abstract
The invention relates to a method for the preparation of di- and polyamines of the diphenylmethane series (MDA) from aniline and formaldehyde, care being taken during the start up that a sufficient excess of aniline with respect to formaldehyde is ensured, said excess amounting to at least 105% of the desired molar ratio of aniline to formaldehyde for the target recipe of the MDA to be produced.