abstract |
A process for the preparation of carrier particles which comprises mixing a dispersion of water, submicron magnetic particles, and ionic surfactant with a latex comprised of resin particles suspended in an aqueous solution containing a surfactant that is counterionic in charge to said ionic surfactant, and a nonionic surfactant; thereafter heating the resulting mixture below about the latex resin glass transition temperature (Tg) while stirring to form aggregates, followed by increasing the temperature of said mixture to about above the latex resin Tg, and subsequently adding additional counterionic or nonionic surfactant solution to minimize, or avoid any further growth in particle size during heating of the mixture about above the latex resin Tg, and wherein said resin Tg is in the range of from between about 45° C. to about 100° C. |