Bleed alleviation using zwitterionic surfactants and cationic dyes
First Claim
1. A process for reducing color bleed in inks employed in ink-jet printing, comprising printing on a medium with an ink having the following composition:
- (a) a vehicle; and
(b) about 0.1 to 10 wt % of at least one water-soluble cationic dye dissolved therein, wherein said vehicle comprises (1) at least one member selected from the group consisting of zwitterionic surfactants and non-ionic amphiphiles, present in an amount that is at least equal to its critical micelle concentration;
(2) about 0.5 to 20 wt % of at least one organic solvent which supports the micelle formation of said at least one member; and
(3) the balance water.
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Accused Products
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 cationic 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 surfactants/amphiphile is described in terms of its critical micelle concentration (cmc), which is a unique value for each amphiphile. 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.
87 Citations
13 Claims
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1. A process for reducing color bleed in inks employed in ink-jet printing, comprising printing on a medium with an ink having the following composition:
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(a) a vehicle; and (b) about 0.1 to 10 wt % of at least one water-soluble cationic dye dissolved therein, wherein said vehicle comprises (1) at least one member selected from the group consisting of zwitterionic surfactants and non-ionic amphiphiles, present in an amount that is at least equal to its critical micelle concentration;
(2) about 0.5 to 20 wt % of at least one organic solvent which supports the micelle formation of said at least one member; and
(3) the balance water. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification