Process for making composite colorant particles

摘要

A process for making composite colorant particles comprising, in order: I) suspending in an aqueous medium, under agitation, finely divided colorant particles to form an aqueous colorant mixture; II) adding to the aqueous colorant mixture an addition polymerization initiator; and III) causing the addition polymerization initiator to form a free radical while continuously introducing continuously to the aqueous colorant mixture a monomer mixture comprising: a) an addition polymerization initiator, and b) at least one ethylenically-unsaturated monomer; thereby forming the composite colorant particles having a colorant phase and a polymer phase.