Patent attributes
A color toner composition for developing latent electrostatic images includes nanopowder-coated toner particles, the powder-coated toner particles being characterized in that each comprises a core toner particle having a volume average diameter, Dp, and the core toner particles have affixed to their surfaces a plurality of discrete colorant powder particles having a volume average diameter, dp, wherein the ratio of Dp/dp is at least about 5 and the weight fraction of colorant powder particles is at least about 0.01 based on the combined weight of core toner particles and colorant powder particles. Preferably, the weight fraction of colorant powder particles is from about 0.3 to about 3 times the product, (ρp/ρr) (d/r) (1+d/r)2, where ρp is the density of the colorant powder particles, ρr the density of the core resin particles, d, the volumetric mean diameter of the colorant powder particles and r the volumetric mean radius of the toner core resin particles.
