To provide a method of preparing pigment particle dispersion that is improved for ink-jet printing.
The objective method of producing composite pigment particles comprises the following steps, in order: I) the finely divided pigment particles are suspended in an aqueous medium with stirring to form an aqueous pigment mixture, II) an addition polymerization initiator is added to the resultant aqueous pigment mixture and III) while the addition polymerization initiator is allowed to form free radicals, a) the addition polymerization initiator and b) a monomer mixture including at least one of ethylenically unsaturated monomer are continuously introduced into the aqueous pigment mixture. Consequently, the composite pigment particles having both of the pigment phase and the polymer phase are produced.
WANG YONGCAI
SCHOFIELD EDWARD
