Patent ID: 7374609

Claim:
A platelet-like pigment whose particles have a length of from 2 μm to 5 mm, a width of from 2 μm to 2 mm and a thickness of from 50 nm to 1.5 μm and a ratio of length to thickness of at least 2:1, the particles having a core of a metallically reflecting material having two substantially parallel faces, the distance between which is the shortest axis of the core, comprising (a) on one parallel face of the core, an SiO y layer wherein 0.95<y≦2.0, wherein the thickness of the SiO y layer (a) is from 20 to 500 nm (b) on the SiO y layer, an SiO x layer wherein 0.03≦x≦0.95, and (c) on the SiO x layer, an SiO z layer, wherein 0.95<z≦2.0 wherein the metallically reflecting material is selected from Ag, Al, Au, Cu, Cr, Ge, Mo, Ni, Ti, Zn, alloys thereof, graphite, Fe 2 O 3 and MoS 2 and the thickness of the core is from 20 to 100 nm.