Colored and coated plateletlike pigments
AssigneeMerck Patent GmbH
InventorsGerd Bauer, Karl Osterried, Christoph Schmidt, Reiner Vogt, Helge-Bettina Kniess, Michael Uhlig, Norbert Schül, Günther Brenner
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Abstract
The invention relates to a platelet-shaped pigment having high luster and high covering power or high transparency, consisting of a transparent, inorganic, platelet-shaped matrix which can contain an additional constituent, characterized in that the additional constituent is a soluble or insoluble colorant and in that the matrix is coated at least on one side with one or more thin, transparent or semi-transparent reflective layers of metal oxides or metals to achieve the luster.
Claims17
A platelet-shaped pigment, consisting essentially of an inorganic, platelet-shaped matrix containing silicon dioxide, a silicate, boron oxide, a borate, an aluminate or a mixture thereof, and optionally containing carbon black, coated with one or more thin, transparent or semi-transparent reflective layers of metal oxides selected from titanium dioxide, zirconium dioxide, zinc oxide, iron (III) oxide, chromium oxide or mixtures thereof which give the pigment an interference color effect, prepared by:
- applying a liquid precursor of the matrix to a continuous belt as a thin film,
- solidifying the liquid film by drying,
- separating the resulting layer from the belt as particles and treating them with a mineral acid and washing them,
- suspending the particles in water and
- coating them with one or more reflective layers of the metal oxides.
A platelet-shaped pigment, consisting essentially of an inorganic, platelet-shaped matrix containing silicon dioxide, a silicate, boron oxide, a borate, an aluminum oxide, an aluminate or a mixture thereof, and optionally containing carbon black, coated with a first thin, transparent layer of tin dioxide and a second thin, transparent layer of titanium dioxide, which give the pigment an interference color effect, prepared by:
- applying a liquid precursor of the matrix to a continuous belt as a thin film,
- solidifying the liquid film by drying,
- separating the resulting layer from the belt as particles and treating them with a mineral acid and washing them,
- suspending the particles in water and
- coating them with the layers of tin dioxide and titanium dioxide.
Dependencies are inferred from the claim text.