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:
Mar. 05, 2013
Filed:
Mar. 26, 2009
Gerda Grund, Coesfeld, DE;
Manfred Kreczinski, Herne, DE;
Gerda Grund, Coesfeld, DE;
Manfred Kreczinski, Herne, DE;
Evonik Degussa GmbH, Essen, DE;
Abstract
The invention relates to a method for producing diaminodiphenyl alkanes, wherein an aromatic amine, which can be substituted or unsubstituted, is reacted with a C1-C3 aldehyde in the presence of a heterogeneous catalyst, said catalyst being a mesoporous acidic ion exchanger based on a divinylbenzene/styrene copolymer and the catalyst having acid centers in a concentration of 4 to 6 eq/kg as measured according to DIN 54 403 and the average pore diameter of the catalyst particles being 10 to 32 nm as measured according to ASTM D 4222 10, and the content of polynuclear compounds in the reaction mixture being ≦10% by weight.