COATING COMPOSITION AND PRINTING MEDIUM

摘要

A printing medium comprising a substrate having at least one surface and a coating on the surface wherein the coating comprises: (a) binder comprising: (1) organic polymer which is substantially free of ammonium groups, (2) first cationic addition polymer consisting essentially of quaternary ammonium-containing mer units derived from addition monomer and ammonium-free mer units derived from addition monomer, and (3) second cationic addition polymer consisting essentially of secondary, tertiary, or both secondary and tertiary ammonium-containing mer units derived from addition monomer and ammonium-free mer units derived from addition monomer, wherein the binder constitutes from 20 to 90 percent by weight of the coating; and (b) finely divided substantially water-insoluble filler particles which have a maximum dimension of less than 500 nanometers, are distributed throughout the binder, and constitute from 10 to 80 percent by weight of coating.