Water-soluble dyes and inks formulated by insolubilizing reactions initiated by loss of water

摘要

A water-soluble ink-jet dye for use in ink-jet printing is designed to undergo a reaction, initiated by the loss of water and natural neutralization, as the ink dries on paper, causing the dye to (1) change and lose solubility and (2) bind to the paper. The dye comprises a polymeric chain, to which one or more chromophores are attached. Also attached to the chain are a plurality of hydroxyl or amine groups, up to approximately one-half of which are converted to carboxyl groups. The ink containing the dye is maintained at a basic pH. Upon printing on a print substrate, the dye is neutralized, causing lactone (from hydroxyl groups) or lactam (from amine groups) ring formation. The resulting reacted dye is substantially totally waterfast on the print substrate.