Patent attributes
The present invention provides an aqueous pigment dispersion liquid being such that a pigment is finely dispersed, and the viscosity, and the particle diameters of the pigment are unlikely to fluctuate, being excellent in storage stability, and enabling preparation of an emulsion-polymerized toner having properly controlled particle diameters while improving the pigment utilization rate. The aqueous pigment dispersion liquid is an aqueous pigment dispersion liquid for an emulsion-polymerized toner containing a pigment, a dispersant, and an aqueous medium. The dispersant is a polymer containing a constitutional unit (A) derived from a monomer (A) such that a group containing a (meth)acryloyloxy group or the like is bonded to one end of a particular polyethylene glycol chain or the like, and a constitutional unit (B) derived from a monomer (B) having a carboxy group or the like, the polymer has a number average molecular weight in terms of polystyrene of 4,000 to 15,000, as measured by gel permeation chromatography, the polymer is contained in a state of being not ionized substantially, and the aqueous pigment dispersion liquid has a pH of 3.0 to 8.4.
