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:
May. 08, 1990
Filed:
Apr. 14, 1988
Applicant:
Inventor:
Karl Schmeidl, Ludwigshafen, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
C09B / ; C09B / ; C09B / ; C09B / ;
U.S. Cl.
CPC ...
534677 ; 534573 ; 534676 ; 534576 ; 534887 ; 534579 ; 534575 ;
Abstract
Liquid formulations of basic azo dyes are prepared from unsubstituted or C.sub.1 -C.sub.4 -alkyl- or C.sub.1 -C.sub.4 -alkoxy-substituted m-phenylenediamine by diazotizing and coupling in carboxylic acid solution, which comprises performing the reaction with 0.76 to 0.95 mole of nitrile, calculated as nitrous acid and based on 1 mole of m-phenylenediamine, and then heating the resulting reaction mixture at from 60.degree. C. to the boiling point of the reaction mixture.