Effect pigments of uniform shape and size
Effect pigments based on a flake-form substrate that have a circular or elliptical shape or have the shape of a polygon, the preparation thereof, and the use thereof, for example, in paints or coatings, or as tracers.
1. An effect pigment of uniform shape and size based on a flake-form, inorganic substrate, comprising inorganic flake-form substrates which are uniform in shape and size and have a circular or elliptical shape or a polygon V n shape, where
n=the number of corners and
n>3, wherein the flake-form inorganic substrate comprises one or more metal oxides, and on the substrate one or more layers comprising a metal oxide, metal oxide hydrates, metal suboxides, metal, metal fluorides, metal nitrides, metal oxynitrides or mixtures thereof.
2. The effect pigment according to claim 1 , wherein n=3, 4, 5, 6, 7 or 8.
3. The effect pigments according to claim 1 , wherein the one or more metal oxides of the substrate is silicon oxide, aluminium oxide, boron oxide, titanium oxide, zirconium oxide and/or iron oxide.
4. The effect pigment according to claim 1 , wherein the flake-form substrate has a circular or elliptical shape with a circle diameter or an ellipse main axis of 3 to 150 μm, or has a polygon V n shape with a greatest diameter of 3 to 150 μm.
5. The effect pigments according to claim 1 , wherein the thickness of the one or more layers is 3 to 300 nm.
6. The effect pigments according to claim 1 , further comprising an organic outer layer.
7. The effect pigments according to claim 1 , obtained by a process comprising
a) applying a film comprising a substrate precursor to a structured support having structuring in circular or elliptical shapes or in the shape of a polygon V n ,
b) solidifying the film by drying,
c) developing a substrate by chemical reaction from the substrate precursor,
d) removing the substrate from the structured support, and
e) optionally washing, drying and/or calcining the substrate.
8. The effect pigment according to claim 7 , wherein the substrate precursor comprises one or more inorganic or organic compounds comprising silicon, aluminium, boron, titanium, zirconium and/or iron.
9. The effect pigment according to claim 7 , wherein the substrate precursor is a silicate.
10. The effect pigment according to claim 7 , wherein the substrate precursor comprises a wetting agent and/or a network former.
11. The effect pigments according to claim 1 , obtained by a process comprising
a) applying a film comprising a substrate precursor to a structured support having a structuring in circular or elliptical shape or in the shape of a polygon V n ,
b) optionally solidifying the film by drying,
c) repeating a) and b) one or more times, in each consecutive case using a different substrate precursor,
d) solidifying the film by drying,
e) developing a substrate by chemical reaction from the substrate precursors,
f) separating the substrate from the structured support, and
g) optionally washing, drying anchor calcining the substrate.
12. A process for preparing effect pigments according to claim 1 , comprising:
a) applying a film comprising a substrate precursor to a structured support having a structuring in circular or elliptical shape or in the shape of a polygon V n ,
b) optionally solidifying the film by drying,
c) repeating steps a) and b) one or more times, in each consecutive case using a different substrate precursor,
d) solidifying the film by drying,
e) developing a substrate by chemical reaction from the substrate precursors,
f) separating the substrate from the structured support, and
g) optionally washing, drying and/or calcining the substrate.
13. A process for preparing effect pigments according to claim 1 , comprising:
a) applying a film comprising a substrate precursor to a structured support having structuring in circular or elliptical shapes or in the shape of a polygon V n ,
b) solidifying the film by drying,
c) developing a substrate by chemical reaction from the substrate precursor,
d) removing the substrate from the structured support, and
e) optionally washing, drying and/or calcining the substrate.
14. A process according to claim 13 , wherein the support is a continuous belt.
15. A process according to claim 13 , wherein the structuring has a circular or elliptical shape with a circle diameter or an ellipse main axis of 3 to 150 μm, or has a polygon V n shape with a greatest diameter of 3 to 150 μm.
16. A process according to claim 13 , wherein the substrate precursor comprises one or more inorganic or organic compounds which are silicon, aluminium, boron, titanium, zirconium and/or iron.
17. A process according to claim 13 , wherein the substrate precursor is a silicate.
18. A process according to claim 13 , wherein the substrate precursor comprises a network former in the form of a soluble salt.
19. A process according to claim 13 , further comprising coating the substrate with one or more layers comprising a metal oxide, metal oxide hydrate, metal suboxide, metal, metal fluoride, metal nitride, metal oxynitride or a mixture thereof.
20. A process according to claim 19 , wherein the coating with one or more layers is carried out wet-chemically, by a sol-gel process or by CVD or PVD process.
21. A process according to claim 13 , further comprising applying an organic outer layer.
22. In a paint, coating, printing ink, toner, plastic material, cosmetic formulation, food material, pharmaceutical product, ceramic material, glass, paper, security material, dry preparation, pigment preparation or tracer comprising conventional excipients and a pigment, the improvement wherein the pigment is one or more effect pigments according to claim 1 .