INKJET INK COMPRISING ENCAPSULATED PIGMENT DISPERSIONS WITH TWO ENCAPSULATION STEPS

摘要

The present disclosure provides an inkjet ink comprising an aqueous vehicle and an encapsulated pigment dispersion. A process for encapsulating pigment dispersions is provided where a pigment is dispersed with a polymeric dispersant in an aqueous solvent system. The encapsulation process has at least two additions of encapsulating monomers followed by polymerization. To a pigment dispersed with a polymeric dispersant is added an encapsulating monomer(s) and a polymerization initiator is added which forms a stage 1 encapsulated pigment. Then a second encapsulating monomer(s) is added and these monomers are polymerized by a second addition of polymerization initiator, forming a second stage encapsulated pigment. The second encapsulating monomer(s) may be added continuously to the stage 1 encapsulated pigment. Such encapsulated pigment dispersions may be used in inkjet inks and are stable to heat, aging test conditions, and solvent challenges. Prints from these inks have better durability.