AQUEOUS PIGMENT DISPERSION, PROCESS FOR PRODUCING THE SAME, AND RECORDING LIQUID COMPRISING THE SAME

摘要

An aqueous pigment-dispersion recording liquid which has high dispersion stability and suitability for delivery and gives a print having an excellent gloss. Also provided is an aqueous pigment dispersion which contains a pigment, a polymer comprising structural units of a cationic monomer and structural units of a hydrophobic monomer (hydrophobic-group-containing cationic polymer), and a polymer comprising structural units of an anionic monomer and structural units of a hydrophobic monomer (hydrophobic-group-containing anionic polymer), the ratio of the number of the anionic groups contained in the hydrophobic-group-containing anionic polymer to the number of the cationic groups contained in the hydrophobic-group-containing cationic polymer being from 1.0 to 8. The ratio (by mole) of the hydrophobic-monomer structural units to the anionic-monomer structural units in the hydrophobic-group-containing anionic polymer is from 5/95 to 50/50, or the content of the pigment is 51 wt.% or higher based on the solid components. This aqueous pigment dispersion is produced by dispersing a pigment with a hydrophobic-group-containing cationic polymer, subsequently subjecting the dispersion to ultrafiltration/microfiltration, and adding a hydrophobic-group-containing anionic polymer thereto.