Merck Patent Gesellschaft MIT Beschrankter Haftung

Constanze Prengel

Klaus Bernhardt

Manfred Kieser

Johann Dietz

Klaus-Dieter Franz

Hartmut Hartner

Axel Von Daacke

Angelika Thurn-Muller

The application relates to deagglomerated and readily dispersible platelet-like substrates with a high degree of softness, which are characterized by a content of 0.5-20% by weight of spherical particles having a small diameter in comparison with the platelet-like substrate, and to a process for their preparation and their use.

Platelet-like substrates

The invention relates to iron oxide pigments based on silica, zirconium dioxide and/or titanium dioxide particles coated with iron oxide, the iron oxide content being more than 350% by weight, relative to the weight of the silica, zirconium dioxide and/or titanium dioxide particles.

Iron oxide pigments

The invention relates to conductive flaky pigments for which a flaky substrate has been coated with an electrically conductive layer, characterized in that the conductive layer comprises a metal oxide pigment layer which is interspersed with carbon black particles and which has at the same time been doped with additional metal oxide particles.

Conductive flaky pigments

The invention is interference pigments having improved covering power and high luster based on platelet-shaped substrates which, if desired, are coated with one or more films comprising one or more metal oxides and are obtainable by adding an aqueous carbon black dispersion and a solution of one or more metal salts to an aqueous suspension of the substrate at a pH suitable for hydrolysis of a film comprising the metal oxide(s) or hydroxide(s) and containing carbon black, in which the product obtained, after being separated off and, if desired, after washing and drying, is ignited at 700.degree.-900.degree. C. in an oxygen-containing atmosphere, during which carbon oxides escape.

Interference pigments

Materials coated with plate-like pigments and characterized in that the coating shows structuring in defined areas due to a difference in the orientation of the pigment particles are highly suitable in the area of general security printing.

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Weiterstadt, Germany

Constanze Prengel