Inclusion pigments of zirconium silicate with included chromic oxide, a process for the preparation and use thereof

US5330571A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Dietrich Speer · Hanau, DE
• Akos Kiss · Alzenau, DE
• Peter Kleinschmit · Hanau, DE
• Jenny Horst · Gelnhausen, DE
• Christel Zell · Rodenbach, DE

Key dates

• Filing date: Mar 12, 1992
• Grant date: Jul 19, 1994
• Expiry date: Mar 12, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2002/08
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Inclusion pigments are discolored having zirconium silicate as a casing component and chromium (III) oxide (Cr.sub.2 O.sub.3) as a discrete, included color compound. The included Cr.sub.2 O.sub.3 has a D.sub.50 value in the range of 0.1 to 3.0 .mu.m and a brilliant light green color. Contrary to non-included Cr.sub.2 O.sub.3 of identical value, the pigments of the present invention may be used for the preparation of decorations without problems and difficulties in their application and maintaining sharp lines and contours. The pigments are suitable for direct pressing and high temperature firing processes. They are prepared by fusing a mixture of zirconium dioxide, silicon dioxide, mineralizators and chromium oxide.