To provide an ink-jet ink composition, a method and a system for improving breed, smear fastness and the optical density of a printed image.
This aqueous ink-jettable ink composition which exhibits a decrease in pH followed by the sedimentation of an ink colorant upon exposure to radiation contains an ink vehicle (a color-developing agent), the ink colorant of an effective amount, having a pH dependent solubility characteristic, and an effective amount of a photo-initiated acid-generator. The method for printing the image on a substrate by improving printing quality, water and smear fastness, and optical density comprises steps of preparing the composition, jetting the ink composition from an ink-jet pen on the substrate and exposing the ink ink-jetted on the substrate to radiation to exhibit the decrease of pH of the ink-jetted ink followed by the sedimentation of the colorant.
STRAMEL RODNEY D
Takahiko Mizobe
Kiyoharu Nishiyama