Patent ID: 9005866
Filing Date: 2015-04-14
Classification: G03G

Abstract:
1. A method for preparing a toner having honeycomb-shaped core-shell structured particles which comprise two or more core layers, each of which is completely covered by a shell layer, said method comprising: (a) dispersing a core-forming binding resin, a colorant, and a dispersant in an organic solvent to form an oil phase dispersing liquid, adding water to the oil phase dispersing liquid to emulsify and form a mixture emulsion; (b) under shearing, adding a coagulating agent to the resultant emulsion from step (a) to form a dispersion of the coagulated core particles; (c) to the resultant dispersion from step (b), adding a shell-forming binding resin dispersion which contain shell-forming binding resin particles, wherein the shell-forming binding resin particles form shells surrounding the coagulated core particles and yield coagulated core-shell structured particles dispersion; (d) to the coagulated core-shell structured particles dispersion from step (c), adding a coagulating agent to merge the coagulated core-shell structured particles into honeycomb-shaped, core-shell structured toner particles, wherein the sphericity of the toner particles is controlled by controlling the coagulating time; and (e) precipitating, washing, filtrating, and vacuum-drying of the toner particles from step (d) to yield honeycomb-shaped, core-shell structured toner particles having two or more core layers, each of which is covered by a shell layer.