| abstract |
Color bleed (the invasion of one color into another on the surface of the print medium) using ink-jet inks is alleviated by employing zwitterionic surfactants (ph-sensitive or pH-insensitive) or ionic or non-ionic amphiphiles. The inks of the invention comprise a vehicle and a dye. The vehicle typically comprises a low viscosity, high boiling point solvent, one or two amphiphiles at concentrations above their critical micelle concentration (cmc), while the dye typically comprises any of the dyes commonly employed in ink-jet printing. The amount of surfactant/amphiphile is described in terms of its critical micelle concentration (cmc), which is a unique value for each amphilphile. Above the cmc, micelles form, which attract the dye molecule and thus control the color bleed. Below the cmc, there is no micelle formation, and thus no control of the color bleed. |