Patent ID: 8282729
Filing Date: 2012-10-09
Classification: A61K,A61Q,C01P,C09C,C09D

Abstract:
1. A multilayer effect pigment comprising: a transparent substrate having a layer of titanium dioxide thereon, the optical thickness of said layer of titanium dioxide being such as to provide a white hue to said substrate; a layer of a low refractive index material on said titanium dioxide layer and an outermost layer of a high refractive index material placed on said low refractive index material layer; said outermost layer comprising a high refractive index material selected from anatase titanium dioxide, rutile titanium dioxide, iron oxide, zirconium dioxide, zinc oxide, zinc sulfide, and bismuth oxychloride, said outermost layer having a optical thickness of from about 45 to 240 nm, said low refractive index material layer having an optical thickness of at least 150 nm to provide a variable pathlength for light dependent on the angle of incidence of light impinging thereon; each layer differs in refractive index from any adjacent layer by at least about 0.2 and wherein at least one layer has an optical thickness which is different from all of the other layers, whereby the pigment is not a quarter-wave stack; and said multilayer effect pigment has a non-white hue.