| 摘要 |
A process for the preparation of toner compositions comprising: (i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment, an ionic surfactant and optionally a charge control agent; (ii) shearing the pigment dispersion with a latex blend comprised of resin particles, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin and charge control agent to form a uniform dispersion of solids in the water, and surfactant; (iii) heating the above sheared blend at a critical temperature region about equal to or above the glass transition temperature (Tg) of the resin, while continuously stirring, to form electrostatically bounded toner size aggregates with a narrow particle size distribution and wherein said critical temperature is from about 0 DEG C. to about 10 DEG C. above the resin Tg, and wherein the resin Tg is from about 30 DEG C. to about 65 DEG C. and preferably in the range of from about 45 DEG C. to about 65 DEG C.; (iv) heating the statically bound aggregated particles from about 10 DEG C. to about 45 DEG C. above the Tg of the resin particles to provide a toner composition comprised of polymeric resin, pigment and optionally a charge control agent; and (v) optionally separating and drying said toner.
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