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. 12, 2016
Filed:
Apr. 09, 2014
Covestro Deutschland Ag, Leverkusen, DE;
Thomas Knauf, Dormagen, DE;
Wolfgang Lorenz, Dormagen, DE;
Stefan Wershofen, Monchengladbach, DE;
Richard Adamson, Leichlingen, DE;
Karsten Becker, Leverkusen, DE;
Covestro Deutschland AG, Leverkusen, DE;
Abstract
The invention relates to a method for producing diamines and polyamines of the diphenylmethane series, wherein first aniline and formaldehyde are reacted in the absence of an acidic catalyst to form a reaction mixture containing animal and water and, after the water has been separated the aminal is reacted by acid catalysis to form a reaction mixture containing diamines and polyamines of the diphenylmethane series, wherein the separation of the water from the aminal is supported by the use of a coalescence aid. According to the invention, a filter bed made front coalescence fiber material is used an coalescence aid.