Back to results
US 7,479,180 B2Granted
Inkjet inks with improved bleed performance
AssigneeHewlett-Packard Development Company, L.P.
InventorSundar Vasudevan
Life of this patent
Estimating the term…
Abstract
Inkjet ink formulations, and ink sets and methods using the same, with improved performance, wherein the inks are formulated to work as an ink set having different polarities.
Claims27
An inkjet ink set, comprising:
- a. a plurality of inks including at least a first and a second ink, each ink comprising an aqueous vehicle;
- b. a first pigmented colorant dispersed in the first ink and having a pre-determined first polarity;
- and
- c. a second pigmented colorant being different than the first colorant and dispersed in the second ink and having a pre-determined second polarity opposite that of the first polarity of the first ink;
- said second ink initially having an initial polarity similar to that of the first ink and the second polarity is achieved by the addition of a surfactant to the second ink in sufficient amount to reverse the second ink's initial polarity from the initial polarity to the second polarity, said second ink having a first zeta potential at the initial polarity and a second zeta potential opposite that of the first zeta potential, wherein the first zeta potential goes through a zero point before reversing its path to the second zeta potential in a direction opposite that of the first polarity such that the difference between the first and second zeta potential is at least 40 mV, wherein at least one of the colorants of either the first or the second ink is substantially achromatic and the other is substantially chromatic.
2 more elements
A method for enhancing bleed performance using an inkjet printer, comprising:
- a. ejecting at least one drop of a first inkjet ink comprising a first pigmented colorant dispersed in the first ink and having a pre-determined first polarity, and;
- b. ejecting at least one drop of a second inkjet ink comprising a second pigmented colorant being different than the first colorant and dispersed in the second ink and having a pre-determined second polarity opposite that of the first polarity of the first ink, said second ink initially having an initial polarity similar to that of the first ink and the second polarity is achieved by the addition of a surfactant to the second ink in sufficient amount to reverse the ink's initial polarity from the initial polarity to the second polarity, said second ink having a first zeta potential at the initial polarity to the second zeta potential opposite that of the first zeta potential, wherein the first zeta potential goes through zero point before reversing its path to the second zeta potential in a direction opposite that of the first polarity such that the difference between the first and second zeta potential is at least 40 mV, and;
- wherein at least one of the colorants of either the first or the second ink is substantially achromatic and the other is substantially chromatic.
An inkjet ink set, comprising:
- a. a plurality of inks including at least a first and a second ink, each ink comprising an aqueous vehicle;
- b. a first pigmented substantially chromatic colorant dispersed in the first ink and having a pre-determined first polarity;
- and
- c. a second pigmented substantially achromatic colorant being different than the first colorant and dispersed in the second ink and having a pre-determined second polarity opposite that of the first polarity of the first ink;
- said second ink initially has an initial polarity similar to that of the first ink and the second polarity is achieved by the addition of a surfactant to the second ink in sufficient amount to reverse the second ink's initial polarity from the initial polarity to the second polarity.
2 more elements
Dependencies are inferred from the claim text.