Patent ID: 6630018
Filing Date: 2003-10-07
Classification: A61K,A61Q,C01P,C08K,C09C,C09D,Y10T

Abstract:
A platelet-shaped pigment, consisting essentially of an inorganic, platelet-shaped matrix containing silicon dioxide, a silicate, boron oxide, a borate, an aluminate or a mixture thereof, and optionally containing carbon black, coated with one or more thin, transparent or semi-transparent reflective layers of metal oxides selected from titanium dioxide, zirconium dioxide, zinc oxide, iron (III) oxide, chromium oxide or mixtures thereof which give the pigment an interference color effect, prepared by:applying a liquid precursor of the matrix to a continuous belt as a thin film, solidifying the liquid film by drying, separating the resulting layer from the belt as particles and treating them with a mineral acid and washing them, suspending the particles in water and coating them with one or more reflective layers of the metal oxides.