Merck Patents
Colored Pigments
Patent No. U.S. 6,884,289 B2
Merck Patent Gmbh has received a patent for a colored pigment. It is comprised of a transparent platelet-shaped substrate which is mica, glass, talc, kaolin, aluminum oxide and SiO2, or BiOCl. The functional coating having a refractive index of n>1.8 and a layer thickness of 20-500 nm, a functional colorless coating having a refractive index of n≤1.8 and a layer thickness of 10-100 nm, an optionally functional colorless coating having a refractive index of n>1.8 and a layer thickness of 20-500 nm, a covering of absorbent pigment particles having a particle size of one to 500 nm and an outer protective layer.