Pigments
The present invention relates to interference pigments based on multicoated flake-form substrates which have on the surface of the substrate a layer sequence comprising (A0) optionally a high-refractive-index coating consisting of a layer of TiO 2 , (A) a high-refractive-index coating consisting of a mixture of TiO 2 and Fe 2 O 3 , which may optionally be doped with one or more further oxides, (B) a high-refractive-index layer consisting of SnO 2 , (C) a high-refractive-index coating which absorbs in the visible wavelength region, and optionally (D) an outer protective layer, and to the use thereof, in particular in paints, coatings, industrial coatings, automobile paints, automotive refinish paints, coil coating, powder coatings, printing inks, plastics, pigment pastes, pigment preparations and in dry preparations, such as, for example, granules.
1. An interference pigment comprising a flake-form substrate and on the surface of the substrate a coating having a layer sequence consisting of:
(A0) optionally a high-refractive-index coating consisting of a layer of TiO 2 ,
(A) a high-refractive-index coating consisting of a mixture of TiO 2 and Fe 2 O 3 , which may optionally be doped with one or more further oxides,
(B) a high-refractive-index layer consisting of SnO 2 ,
(C) a high-refractive-index coating which absorbs in the visible wavelength region,
and optionally
(D) an outer protective layer.
2. Interference pigment according to claim 1 , wherein the flake form substrate is of natural or synthetic mica, glass flakes, Al 2 O 3 flakes, SiO 2 flakes or TiO 2 flakes or flake-form materials coated with metal oxides.
3. Interference pigment according to claim 1 , wherein the flake form substrate is of mica flakes, glass flakes or Al 2 O 3 flakes.
4. Interference pigment according to claim 1 , wherein the flake form substrate is of SiO 2 -coated glass flakes.
5. Interference pigment according to claim 1 , wherein coating (A) is doped with one or more oxides selected from Al 2 O 3 , Ce 2 O 3 , B 2 O 3 , ZrO 2 , and SnO 2 .
6. Interference pigment according to claim 1 , wherein coating (C) is
a TiO 2 layer followed by an Fe 2 O 3 layer, or
an Fe 2 O 3 layer, or
a layer consisting of a mixture of TiO 2 and Fe 2 O 3 , or
a TiO 2 layer followed by a layer of Carmine Red, or
a TiO 2 layer followed by a layer of Berlin Blue.
7. Interference pigment according to claim 1 , wherein the pigment has the following layer sequence on the substrate:
substrate+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
substrate+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
substrate+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
substrate+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
substrate+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 3 O 4
substrate+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Carmine Red
substrate+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Berlin Blue
substrate+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
substrate+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
substrate+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
substrate+TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
substrate+TiO 2 /Fe 2 O 3 +SnO 2 +Fe 3 O 4
substrate+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Carmine Red or
substrate+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Berlin Blue.
8. Interference pigment according to claim 1 , wherein the pigment has the following structure:
synthetic mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
synthetic mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
synthetic mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
synthetic mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
synthetic mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
synthetic mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
synthetic mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
synthetic mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
glass flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
glass flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
glass flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
glass flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
glass flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
glass flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
glass flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
glass flakes+TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
glass flakes+SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
glass flakes+SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
glass flakes+SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
glass flakes+SiO 2 +TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
glass flakes+SiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
glass flakes+SiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
glass flakes+SiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
glass flakes+SiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
Al 2 O 3 flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
Al 2 O 3 flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
Al 2 O 3 flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
Al 2 O 3 flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
Al 2 O 3 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
Al 2 O 3 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
Al 2 O 3 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
Al 2 O 3 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
SiO 2 flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
SiO 2 flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
SiO 2 flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
SiO 2 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
SiO 2 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
SiO 2 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
SiO 2 flakes+TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
natural mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
natural mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
natural mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3
natural mica flakes+TiO 2 +TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3
natural mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 /Fe 2 O 3
natural mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +TiO 2 /Fe 2 O 3
natural mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +TiO 2 +Fe 2 O 3 or
natural mica flakes+TiO 2 /Fe 2 O 3 +SnO 2 +Fe 2 O 3 .
9. Interference pigment according to claim 7 , wherein the interference pigment additionally has an outer protective layer (D).
10. Interference pigment according to claim 1 , wherein the thickness of all layers (A0)-(C) together on the substrate is ≦300 nm.
11. Process for the preparation of an interference pigment according to claim 1 , comprising applying metal oxides corresponding to the layers to the flake-form substrate by wet-chemical methods, by hydrolytic decomposition of metal salts in aqueous medium or by gas-phase coating in a fluidised-bed reactor.
12. A composition selected from the group consisting of compositions for: paints, coatings, industrial coatings, coil coating, automobile paints, automotive refinish paints, powder coatings, printing inks, security printing inks, plastics, ceramic materials, cosmetic formulations, glasses, paper, toners for electrophotographic printing processes, seed, greenhouse sheeting and tarpaulins, absorbers in the laser marking of paper and plastics, cosmetic formulations, the preparation of pigment pastes with water, organic and/or aqueous solvents, the preparation of pigment preparations and dry preparations, the mass colouring of foods, the colouring of coatings of food products and pharmaceutical products; which comprises a interference pigment according to claim 1 .
13. Formulations comprising one or more interference pigments according to claim 1 .
14. Pigment preparations comprising one or more binders and or more interference pigments according to claim 1 .
15. Dry preparations comprising interference pigments according to claim 1 .