Patent ID: 7819966

Claim:
A dry powder coating composition that comprises surface-modified pearlescent pigments and powder coating binder, each said surface modified pearlescent pigment comprising: a pearlescent pigment comprised of a platelet-shaped substrate of one refractive index and an optically transmissive inorganic body of another refractive index higher than the one refractive index deposited atop the substrate, the pearlescent pigment having over a surface thereof at least one organic phosphorus compound of the general formula (I) R 1 R 2 P(O)(OR 3 ) (I), or of the general formula (II) R 1 P(O)(OR 3 )(OR 4 ) (II), or a combination thereof where R 1 and R 2 independently of one another are hydrogen or an organic radical having 1 to 30 carbon atoms, with the proviso that R 1 and R 2 are not simultaneously hydrogen, R 3 and R 4 independently of one another are H or alkyl having 1-10 carbon atoms; wherein said dry powder coating composition includes 0.1% to 12% of surface modified pearlescent pigments by weight and 88% to 99.9% of powder coating binder by weight, said surface modified pearlescent pigments and said powder coating binder being bonded, wherein said surface modified pearlescent pigments and said powder coating binder are bonded by mixing and heating up to the softening temperature of said powder coating binder, and wherein said dry powder coating composition when applied exhibits a higher chroma value than a powder coating composition containing an identical amount of said pearlescent pigment without an organic phosphorus compound of the general formula I or general formula II over a surface thereof.