Process for fine division of organic pigments by precipitation

US6537364B2 · kind B2 · utility

Assignee

• Clariant Corporation · DE

Inventors

• Erwin Dietz · Kelkheim, DE
• Joachim Weber · Frankfurt am Main, DE
• Dieter Schnaitmann · Eppstein, DE
• Christian Wille · Weinheim, DE
• Leonhard Unverdorben · Uttenreuth, DE
• Klaus Brychcy · Frankfurt am Main, DE

Key dates

• Filing date: Oct 5, 2001
• Grant date: Mar 25, 2003
• Expiry date: Oct 5, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B67/0001
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The invention provides a process for the fine division of pigments which comprises dissolving coarsely crystalline crude pigments in a solvent and precipitating them with a liquid precipitation medium by spraying the pigment solution and the precipitation medium through nozzles to a point of conjoint collision in a reactor chamber enclosed by a housing in a microjet reactor, a gas or an evaporating liquid being passed into the reactor chamber through an opening in the housing for the purpose of maintaining a gas atmosphere in the reactor chamber, and the resulting pigment suspension and the gas or the evaporated liquid being removed from the reactor through a further opening in the housing by means of overpressure on the gas entry side or underpressure on the product and gas exit side.