Patent ID: 7578879

Claim:
Surface-modified effect pigments based on flake-form substrates, which are sheathed with one or more layers of immobilised UCST polymer having layer Thicknesses of 2-500 nm, wherein the UCST polymer is a polystyrene, polystyrene copolymer or polyethylene oxide copolymer, or a mixture thereof, wherein said surface-modified effect pigments based on flake-form substrates are holographic pigments, pearlescent pigments, interference pigments, multilayered pigments, metal-effect pigments, goniochromatic pigments and/or BiOCl pigments, which surface-modified effect pigments are prepared by applying the UCST polymer to the surface of the effect pigments by precipitation in water and/or an organic solvent, and irreversibly immobilizing said UCST polymer on the surface of the effect pigments.