Method for producing pigment dispersion, and method for producing toner for developing electrostatic charge images

Abstract

A method for producing a pigment dispersion includes: wet-dispersing a mixture A containing an organic pigment, a flame retardant, a dispersant, and an aqueous medium by using a media disperser to form a mixture B; and wet-dispersing the mixture B by using a media disperser to form a mixture C. The media disperser in the wet-dispersing of the mixture A and the media disperser in the wet-dispersing of the mixture B are annular-type media dispersers each having a cylindrical vessel, a cylindrical rotor that is disposed inside the cylindrical vessel and that rotates to disperse the mixture, and a screen-type media separator that separates media particles and the mixture. The number-average particle size MA of the media particles in the media disperser in the wet-dispersing of the mixture A and the number-average particle size MB of the media particles in the media disperser in the wet-dispersing of the mixture B satisfy the following formula (1) and the following formula (2): 0.5 mm≥MA>MB≥0.05 mm,  Formula (1): 0.3 mm≥MB≥0.05 mm.  Formula (2):

Dependencies are inferred from the claim text.