pigment from merck
Patent No. U.S. 6,783,584 B2
Merck Patent GmbH has received a patent for a high-chromatic flaky pigment that is comprised of a flaky substrate of a metal flake pigment coated with a silicon dioxide film or an aluminum oxide film or a silica and alumina film. As a protective film, the substrate is coated over its entire surface with a metal oxide, selected from a group consisting of titanium dioxide, zirconium oxide, iron oxide, tin oxide, zinc oxide and cerium oxide, providing an interference color and further coated with a semi-transparent thin metal film to enhance the interference color of the pigment, wherein the pigment exhibits a color flop effect.