Disazo compounds and formulations containing same

US4981489A · kind A · utility

Assignee

• Basf Lacke & Farben Aktiengesellschaft · DE

Inventors

• Wolfgang Ruff · Stuttgart, DE
• Egon Liedek · Eßlingen, DE
• Gerhard Berger · Stuttgart, DE
• Hans W. Sonneborn · Schwäbisch Gmünd, DE

Key dates

• Filing date: Oct 23, 1989
• Grant date: Jan 1, 1991
• Expiry date: Oct 23, 2009

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S534/01
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Disazo compounds based on 4,4'-diaminodiphenyl compounds contain not less than 50% by weight of a disazo compound of the general formula EQU A--N.dbd.N--Z--N.dbd.N--B (I) where Z is a radical of an unsubstituted or symmetrically substituted diphenylene, A is a radical of a coupling component of a 1-phenylpyrazolone or of an acetoacetarylide, where the phenyl and the aryl radical is subtsituted by sulfo or carboxyl groups, and B is a radical of a coupling component based on 1-phenylpyrazolone or acetoacetarylide, which are free of sulfo and/or carboxyl groups. The disazo compounds can be obtained by coupling the tetrazotized diamine H.sub.2 N--Z--NH.sub.2 to the coupling component AH containing an acidic group in a medium containing a mineral acid, and then coupling the product to BH in a buffered medium (pH about 4). The novel disazo compounds are suitable as additives to pigments, in particular azo and disazo pigments, for improving the transparency and heat stability of the pigment particles, and the flow behavior.