Patent ID: 7517404

Claim:
A pigment, the particles of which have a length of from 2 μm to 5 mm, a width of from 2 μm to 2 mm, and a thickness of from 20 nm to 2 μm, and a ratio of length to thickness of at least 2:1, wherein the particles consist of a core of SiO y with 1.1≦y≦1.8, having two substantially parallel faces, the distance between which is the shortest axis of the core, and (a) a dielectric material layer having a high index of refraction and optionally an additional layer or layers, which layer or layers consist of a material selected from a dielectric material having a high index of refraction, a dielectric material having a low index of refraction, one or more inorganic colorant, one or more organic colorant, a semi-transparent metal layer and mixtures thereof, wherein the metal of the semi-transparent metal layer is selected from Cr, Mo, W, Al, Cu, Ag, Au and Ni, and which pigment particle may also have a surface treatment.