abstract |
The ink of the invention comprises a vehicle and a colorant. The colorant is a water-insoluble macromolecule that has been chemically modified to be water soluble by addition of functional groups to the surface of the chromophores resulting in water soluble colorant particles. The resulting chromaphore is called a macromolecular chromophore (MMC). The performance of these MMCs is improved by substitution of (a) the normal counter-cations with substituted ammonium cations or (b) the normal counter-anions with any of a variety of organic and inorganic anions. The inks described herein demonstrate high edge acuity, high optical density, fast drying times, high waterfastness, and high smearfastness. |