Patent ID: 7393571

Claim:
A coated substrate comprising a substrate and at least one layer thereon comprising (a) inorganic oxide particles having i) a median particle size in the range of 0.05 to 3 microns; and ii) porosity such that when an aqueous dispersion of the particles and fluid phase is dried at least 0.5 cc/g of pore volume as measured by BJH nitrogen porosimetry is from pores having a pore size of 600 Å or smaller; and (b) binder; and said particles possess a viscosity derived pore volume (Pva) in the dispersion of at least 0.5 cc/g as governed by the relationship: slope = - 2.5 ⁢ ⁢ ( 1 ρ ⁢ ⁢ s + PVa ) ⁢ ⁢ ρ ⁢ ⁢ f where the slope is about 2.4 or greater, ρs is the particles skeletal density and ρf is the density of the fluid phase in the dispersion.