TONER FOR ELECTROSTATIC DEVELOPMENT BY SUSPENSION TREATMENT ACCOMPANIED WITH REVERSE NEUTRALIZATION AND PREPARATION METHOD

PURPOSE: A toner for electrostatic development and its preparation method are provided, to obtain low softening point and low melting viscosity and improve offset resistance even in high rate development and fixation. CONSTITUTION: The method comprises the steps of preparing a linear low molecular weight polyester resin having a carboxyl group at the end; preparing a crosslinked polyester resin having a carboxyl group at the end; neutralizing the polyester resin and adding water to the polyester resin to prepare a polyester resin aqueous solution; preparing a crosslinked ethylenically copolymerized latex; adding a colorant, a charge control agent and a releasing agent to the polyester resin aqueous solution and applying high shear force to mix it to prepare a coloring resin dispersion; adding a colorant, a charge control agent and a releasing agent to the polyester resin aqueous solution, applying high shear force to mix it and mixing the coloring resin dispersion with the latex to prepare a coloring resin dispersion; adding the two coloring resin dispersion in an aqueous solution containing an acidic compound, respectively, applying high shear force to reverse neutralize them to generate toner particles, and heating the toner particles to stabilizer it; filtering and washing the toner particles and vacuum drying it; and adding hydrophobic silica or hydrophobic titanium dioxide to the toner particles and mixing them.