| 摘要 |
The present invention resides in a layered composite pigment comprising a first pigment particle having a charge of one sign and a second pigment particle having a charge of opposite sign to said one sign. The first pigment particle is an inorganic pigment particle. The first inorganic pigment particle has adsorbed on its surface an organic polymeric dispersant. The dispersant is selected from the group consisting of (a) an anionic or cationic polyelectrolyte dispersant; (b) a cationic synthetic latex having dispersant functionality; and (c) a cationic water-soluble binder having dispersant functionality. The dispersant is adsorbed onto the surface of the inorganic pigment particle in an amount effective to disperse the inorganic particle in an aqueous medium. The second pigment particle is selected from the group consisting of (a') an anionic or cationic synthetic latex particle or swollen binder particle which said swollen binder particle has a particle size greater than 0.05 micron; and (b') a second inorganic pigment particle which has adsorbed on its surface an anionic polyelectrolyte dispersant in an amount effective to disperse the second inorganic particle in an aqueous medium. The layered composite pigment comprises the combination of (a') with an inorganic pigment particle dispersed with (a), (b) or (c); or (b') with an inorganic pigment particle dispersed with only (b) or (c).
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