ZIRCONIUM SILICATE OCCLUSION PIGMENTS WITH SPINEL OCCLUSIONS, THEIR PREPARATION AND THEIR USE

摘要

The invention relates to occlusion pigments based on zirconium silicate as the covering substance and cobalt-free spinels, preferably ZnFe2O4, NiFe2O4 or (Fe,Cr)3O4, as a discretely occluded coloured compound. Preparation is carried out by calcining a mixture of a source of zirconium dioxide, a source of silicon dioxide, mineralisers and cobalt-free oxides in a spinel-forming composition. The pigments are distinguished by their good glaze and colour stability as well as bleeding-out resistance under customary decorative firing conditions.