Continuous process for preparing metal complex pigments

US6448385B2 · kind B2 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Udo Herrmann · Dormagen, DE
• Lothar Weismantel · Neunburg vorm Wald, DE
• Frank Linke · Recklinghausen, DE
• Ronald Gobel · Leverkusen, DE
• Bernhard Krumbach · Leverkusen, DE
• Wolfgang Frank

Key dates

• Filing date: Mar 30, 2001
• Grant date: Sep 10, 2002
• Expiry date: Mar 30, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B67/0015
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for preparing metal complexes of polyvalent metal ions with azo compounds of formula (I) or tautomeric structures, in which R and R′ are —OH, —NH2, —NH—CN, aryl-amino, acylamino, or p-chlorophenyl, and R1 and R1′ are independently —OH or —NH2, that intercalate an intercalate by(1) stirring an aqueous dispersion of an alkali metal salt of the azo compound with the polyvalent metal salt at 10 to 35° C.,(2) admixing an aqueous solution, dispersion, or emulsion of the intercalate,(3) passing the mixture through a reaction zone at 85 to 140° C., while regulating the pH so that the product dispersion leaving the reaction zone has a pH of 0.5 to 3,(4) adjusting the pH of the mixture to at least pH 5, and(5) isolating the intercalated metal complex.