Patent · US Expired

Monoclinic zirconium dioxide, method of its production and use

US5318765A · kind A · utility

8Cited by

5References

9Claims

0Family size

Assignee

Degussa AG · DE

Inventors

Dieter Binder · Wien, AT
Peter Kleinschmit · Hanau, DE
Hans Hoffmeister · Gelnhausen, DE
Roland Reuter · Darmstadt, DE

Key dates

Filing date	Feb 27, 1992
Grant date	Jun 7, 1994
Priority date	—
Expiry date	Feb 27, 2012

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01P2006/80
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

A monoclinic zirconium dioxide with an SiO.sub.2 content below 1.0% by weight is provided which is characterized by dendrite-shaped particles with an average grain size (d.sub.50 value) in a range of 0.5 .mu.m to 3.0 .mu.m and a specific surface (BET) in a range of 3 to 15 m.sup.2 /g. This zirconium dioxide is produced by thermally splitting zirconium silicate in a high-frequency- or medium-frequency induction melting furnace with sintering crust crucible, quenching the melt by blowing on a stream of melt with air and/or spraying it with water and leaching out the thermally split zirconium silicate with concentrated alkali lye at 100.degree. 200.degree. C. The zirconium dioxide of the invention provides a material with improved suitability for the production of zirconium silicate pigments of the host lattice type and inclusion type so as to provide for more color-intensive pigments.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.