Complex inorganic effect materials
View Patent ↗The present invention relates to a complex inorganic color effect pigment material based on multiply coated platelet-shaped substrates wherein one of the layers is a complex inorganic colored pigment. The present color effect pigment may be used in automotive applications, security inks, and decorative coatings.
1. A color effect material comprising a laminar substrate having at least one layer sequence comprising: (A) a layer having a high refractive index disposed on the substrate; (B) a layer having a low refractive index disposed on said layer (A); (C) a layer having a high refractive index disposed on said layer (B); and (D), an external layer disposed on said layer (C); wherein at least one of said layers (A) or (C) comprises copper chromite; and wherein the outermost layer of said color effect material contains no copper chromite.
2. The color effect material of claim 1 wherein the layer (B) has a refractive index≦1.9.
3. The color effect material of claim 1 wherein the layer (B) is silicon dioxide.
4. The color effect material of claim 1 wherein the layer (A) and the layer (C) both have a refractive index of ≧1.95.
5. The color effect material of claim 1 wherein the layer (A) is a metal oxide and the layer (C) is copper chromite.
6. The color effect material of claim 1 wherein the layer (A) is iron oxide.
7. The color effect material of claim 1 wherein the layer (A) and the layer (C) both comprise metal oxides.
8. The color effect material of claim 3 wherein the layer (A) is iron oxide.