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. 02, 1976
Filed:
Dec. 11, 1974
Applicant:
Inventors:
Rudolf Braden, Odenthal-Scheuren, DT;
Hans Knupfer, Schildgen, DT;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
260510 ; 260508 ;
Abstract
Process for the preparation of 4,4'-diaminostilbene-2,2'-disulphonic acid or its alkali salts by catalytic hydrogenation of 4,4'-dinitrostilbene-2,2'-disulphonic acid in an aqueous medium, characterized in that the hydrogenation is carried out on a cobalt catalyst at 70.degree.-180.degree. C and 5-150 bars of H.sub.2, at a pH value between 6.0 and 8.5.