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:
Jun. 06, 1989
Filed:
Jan. 12, 1988
Applicant:
Inventor:
Rainer Gerlach, Leverkusen, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
534578 ; 534587 ; 534615 ; 534753 ; 534768 ; 534770 ; 534787 ; 534788 ; 534791 ; 534794 ; 534795 ; 534850 ; 534852 ; 534887 ;
Abstract
A universally usable process for preparing azo dyestuffs by oxidative coupling consists in carrying out the oxidation in the presence of redox mediators with a standard potential of 0.2-1.5 volts and, if appropriate, an additional oxidizing agent with a standard potential of 0.25-2.5 volts, wherein the sum of the oxidation equivalents should be at least 4. The preferred redox mediator is iodine. The process is particularly suitable for the preparation of heteroaromatic azo dyestuffs using an aniline coupling component.