Degussa Aktiengesellschaft

Cerdec Aktiengesellschaft Keramische Farben

Jorg Sperlich

Stipan Katusic

Andreas Schulz

Hauke Jacobsen

Ralph Brandes

Dietrich Speer

Werner Hartmann

Norbert Giesecke

Kai Dorer

Stephan Ludwig

Katia Jackow

The invention relates to spherical colored pigments having an average particle diameter of less than 10 .mu.m on the basis of an oxide, a mixed oxide or a silicate. The pigments are obtainable by means of spray-pyrolysis technology: a solution containing oxide-forming or silicate-forming metal compounds is converted into an aerosol and the latter is fed, preferably after predrying, to a pyrolysis reactor; the pigment is separated from the pyrolysis gas. The colored pigments according to the invention are suitable for the production of ceramic decorations and for the coloring of plastics, synthetic foils, fibers and also lacquers. By reason of the spherical shape, unusual technical application properties are achieved.

Spherical color pigments, process for their production and use thereof

The invention makes available for the first time pure green decoration coloring substances for high-temperature firing at least at 1000.degree. C., in particular at 1100 to 1250.degree. C., with a color hue angle h in the range of 160.degree..+-.20.degree.. The decoration coloring substance comprises chromium oxide as the pigment and one or several glass frits as glass flux, and additionally a cobalt compound from the series CoO, Co(OH).sub.2 and Co compounds forming CoO below or at the firing temperature, with the atomic ratio of Co to Cr being in the range of 0.01 to 0.35, preferably 0.15 to 0.25.

Green decoration coloring substance for high-temperature firing, process

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 SiO.sub.2, SnO.sub.2 and ZrO.sub.2 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.

Spherical pigments, process for producing them and use thereof

Growing community of inventors

Offenbach, Germany

Jorg Sperlich