Method for the preparation of gray-green pigments based on zirconium silicate/vanadium compounds and sodium compound

US5021092A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Dietrich Speer · Hanau, DE
• Akos Kiss · Alzenau, DE
• Peter Kleinschmit · Hanau, DE

Key dates

• Filing date: Aug 4, 1989
• Grant date: Jun 4, 1991
• Expiry date: Aug 4, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2002/70
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The preparation of gray-green unitary pigment bodies based on zirconium silicate-vanadium oxide wherein a mixture of zirconium oxide and silicon oxide in the presence of a vanadium and lithium compound is calcined above 600.degree. C. and wherein the amount of V.sub.2 O.sub.5 is more than 17 percent by weight and the amount of lithium compound added is such that the atom ratio Li/Li+V is from 0.1 to 0.5.