Process for the continuous preparation of encapsulated toner

摘要

A process for the continuous preparation of an encapsulated toner comprised of a core comprised of polymer and pigment encapsulated within a polymer shell, which process comprises continuously separately feeding an oil phase containing core monomers, oil soluble shell monomers and pigment and an aqueous phase containing surfactant into a continuous flowthrough mixing tank; homogenizing the aforementioned two phases to enable small oil droplets with an average diameter of from between about 3 to about 25 microns; overflowing the resulting droplets to at least one continuously stirred tank reactor while simultaneously feeding water soluble shell monomer to said stirred reactor to effect interfacial polymerization thereby causing shell formation; and thereafter allowing the encapsulated droplets to flow into a reactor or reactors and heating the reactor or reactors to effect free radical polymerization of the core monomers, followed by cooling, and isolating the said encapsulated toner.