Preparation of brilliant, transparent pigmentary bromo-isoviolanthrone of high tinctorial strength

US4298534A · kind A · utility

Assignee

• BASF SE

Inventors

• Helmut Hoch
• Erwin Hahn · Heidelberg, DE
• Heinrich Hiller · Monsheim, DE

Key dates

• Filing date: Mar 4, 1980
• Grant date: Nov 3, 1981
• Expiry date: Mar 4, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B3/22
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of pigmentary forms of bromoisoviolanthrone, wherein the leuco compound is oxidized in an aqueous alkaline medium, in the presence of a surfactant, at from 10.degree. to 100.degree. C., with exposure to shearing forces. The pigment obtained gives full-shade colorations which are very transparent and very brilliant, while in white reductions very deep colorations are obtained.