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:
Jan. 20, 1981
Filed:
Feb. 09, 1978
Applicant:
Inventors:
Herbert Hugl, Leverkusen, DE;
Hans-Gunter Otten, Leverkusen, DE;
Hans W Petroll, Leverkusen, DE;
Karlheinz Wolf, Leverkusen, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
D06P / ; D06P / ;
U.S. Cl.
CPC ...
8574 ; 8602 ; 260208 ; 260165 ;
Abstract
Azo dyestuffs which contain, as the coupling component an indole of the formula ##STR1## wherein R denotes an optionally substituted alkyl radical, an optionally substituted aryl radical or an optionally substituted aralkyl radical, and the benzene ring A can be further substituted, frequently exhibit an undesired irreversible change in the color shade in acid solutions, which surprisingly can be prevented by adding nitrogen-containing complex-forming substances.