Patent ID: 7223472

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 50 nm to 1.5 μm and a ratio of length to thickness of at least 2:1, the particles having a core S D having two substantially parallel faces, the distance between which is the shortest axis of the core, and optionally having layers Q Z and/or D M applied to those parallel faces or to the entire surface, and wherein the core S D has a thickness of from 20 to 350 nm and comprises from 50 to 97 atom % silicon, bonded to from 3 to 95 atom % oxygen per 100 atom % silicon; optionally, a layer Q Z having a thickness of from 0 to 500 nm is present, which is applied to the core S D and comprises from 17 to 51 atom % silicon, which is bonded to more than 95 atom % oxygen per 100 atom % silicon; and optionally, a layer D M having a thickness of from 0 to 300 nm is present, which has a transparency of from 50 to 100% and a complex refractive index Ñ=n+ik according to the condition √{square root over (n 2 +k 2 )}≧1.5 at the wavelength of maximum visible reflection of the particles, which is substantially composed of carbon, an organic compound, a metal, a dielectric or a mixture thereof, and which is either on the core S D or, in the presence of a layer Q Z , is separated from the core S D by the layer Q Z .