Effect pigments
AssigneeMerck Patent GmbH
InventorsSabine Schoen, Michael Jungnitz, Stefan Schlueter, Kirsten Fritsche, Carsten Plueg, Stephanie Andes, Ulrich Schoenefeld
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Abstract
Effect pigments based on Al2O3 flakes with high weather resistance and less photoactivity and to their use thereof in paints, industrial coatings, automotive coatings, printing inks, cosmetic formulations. The effect pigments have a ratio of the amount by weight of Al2O3 of the Al2O3 flake and the amount by weight of the metal oxide(s) of the coating layer(s) in the range of from 27:73 to 83:17 based on the total weight of the effect pigment.
Claims45
An effect pigment based on an Al2O3 flake which comprises an Al2O3 flake coated with one or more layers of a metal oxide and/or a metal oxide mixture wherein the ratio of the amount by weight of Al2O3 of the Al2O3 flake to the amount by weight of the metal oxide(s) of the coating layer(s) is in the range of from 27:73 to 83:17 based on the total weight of the effect pigment;
- and
- wherein the pigment further comprises on its surface a protective layer, wherein the protective layer contains at least one rare earth metal oxide in an amount of 0.2-2% by weight based on the total pigment, 0.2-2 wt. % of SiO2, 0.2-4 wt. % of Al2O3 and/or ZrO2 and 1-10 wt. % of an organic compound, wherein the organic compound is an organic coupling agent selected from the group consisting of organofunctional silanes, amino compounds and organic phosphorus compounds.
An effect pigment based on an Al2O3 flake which comprises an Al2O3 flake coated with one or more layers of a metal oxide and/or a metal oxide mixture wherein the ratio of the amount by weight of Al2O3 of the Al2O3 flake to the amount by weight of the metal oxide(s) of the coating layer(s) is in the range of from 27:73 to 83:17 based on the total weight of the effect pigment;
- and wherein the pigment further comprises on its surface a protective layer,
- wherein, the protective layer consists of:
- 4-1.5 wt. % of Ce2O3, 0.4-1 wt. % of SiO2 and 0.5-2.5 wt.% of Al2O3 and/or ZrO2 and 2-5 wt. % of an organic compound which is a coupling agent, based on the total weight of the pigment.
Dependencies are inferred from the claim text.