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:
May. 10, 1994
Filed:
May. 01, 1992
Applicant:
Inventors:
Christian Konig, Kaarst, DE;
Manfred Gallus, Krefeld, DE;
Reinhold Wullner, Krefeld, DE;
Franz-Moritz Richter, Marne, DE;
Rudolf Uchdorf, Krefeld, DE;
William C Forester, Upter St. Clair, PA (US);
Assignees:
Bayer Aktiengesellschaft, Leverkusen, DE;
Miles Inc., Pittsburgh, PA (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
521163 ; 521155 ; 564331 ; 564333 ; 564335 ;
Abstract
A process for production of polyamines of the diphenylmethane series through a condensation reaction of aniline with formaldehyde in the presence of an acid catalyst, neutralization of the acid catalyst after reaction completion, and distillation of the resultant polyamine mixture is described. The key feature of the process is the abrupt increase in reaction temperature after the condensation reaction or after the first rearrangement step.