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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.:

US 4245995 B1

PDFFull Text
Date of Patent:
Jan. 20, 1981

Filed:

Feb. 09, 1978

Stabilization of anionic indole dyestuffs

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:

Sprung, Felfe, Horn, Lynch & Kramer

Primary Examiner:

Joseph L Schofer

Assistant Examiner:

Maria S Tungol

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.

Find Patent Forward Citations

Hugl, Herbert. (1981). Stabilization of anionic indole dyestuffs (U.S. Patent No. 4245995). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4245995

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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