Preparation of pigmentary form isoindoline

US4271301A · kind A · utility

Assignee

• BASF SE

Inventors

• Wolfgang Lotsch · Beindersheim, DE
• Peter Hilbert · Worms, DE

Key dates

• Filing date: Jan 5, 1979
• Grant date: Jun 2, 1981
• Expiry date: Jan 5, 1999

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B57/04
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for converting finely particled agglomerated crude isoindoline pigments of the formula ##STR1## where A is ##STR2## and B is the radical of an unsubstituted or substituted barbituric acid, or A and B are both such a barbituric acid radical, into tinctorially valuable pigmentary forms, wherein the crude pigment, which consists of primary particles having a mean size of .ltoreq.0.1 .mu.m, is subjected to shearing forces in water, and thereafter the aqueous suspension is heated at from 90.degree. to 160.degree. C. in the presence or absence of a surfactant and the pigment is isolated. Easily dispersible, high-hiding to extremely high-hiding pigments are obtained, which give brilliant colorations of improved lightfastness and fastness to weathering.