Process for the production of rutile mixed-phase pigments

US4919726A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Jakob Rademachers · Krefeld, DE
• Volker Wilhelm · Bensberg, DE

Key dates

• Filing date: Jan 18, 1989
• Grant date: Apr 24, 1990
• Expiry date: Jan 18, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2002/30
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for the production of rutile mixed-phase pigments comprising calcinating of a solid mixture of titanium dioxide or titanium oxide hydroxide with a dye-producing compound of a metal, in one or more directly heated, continuously operated rotary kilns, wherein in terms of material flow, air is introduced into the kiln atmosphere countercurrently to the direction of flow of the solids in the second half of the rotary kiln.