Spherical pigments, process for producing them and use thereof

摘要

The invention relates to pigments consisting of substantially spherical particles with a mean particle diameter of less than 10 mu m, on the basis of an oxidic or silicate substrate material with noble metal distributed extremely finely on and/or in the particles. Preferred pigments are purple-colored and are based on an oxide from the series SiO2, SnO2 and ZrO2 and gold as noble metal. The pigments are suitable for the production of ceramic decorations and for the dyeing of plastics, synthetic films and fibers as well as lacquers. Exceptional application properties are obtained by virtue of the spherical shape. The pigments are obtainable by a spray-pyrolysis process in which an aerosol consisting of a solution of at least one noble metal compound and an oxide- or silicate-forming precursor is subjected to pyrolysis; the pigment is separated from the pyrolysis gas.