| 摘要 |
<p>A process for the preparation of toner compositions with controlled particle size comprising: (i) preparing a pigment dispersion in water, which dispersion comprises a pigment, and an ionic surfactant in controlled amounts of from about 0 5 percent to about 10 percent based on the amount of water; (ii) shearing the pigment dispersion with a latex mixture comprised of a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant, a nonionic surfactant, and resin, thereby causing a flocculation or heterocoagulation of the formed particles of pigment and resin; (iii) further stirring of the resulting mixture to form electrostatically bound relatively stable toner size aggregates with a narrow particle size distribution; (iv) adding further surfactant to minimize further growth, or freeze the particle size in the coalescence step; and (v) heating above the glass transition temperature of the resin (Tg) to coalesce the statically bound aggregated particles to form said toner composition comprising resin and pigment.</p> |
