Additive for high optical density inkjet ink
AssigneeE.I. du Pont de Nemours and Company
InventorChristian Jackson
Life of this patent
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Abstract
This invention pertains to an aqueous inkjet ink with a certain chelator additive, inkjet ink sets based on this aqueous inkjet ink, and to a method of printing with these inks and ink sets, whereby optical density (OD) of a printed image is increased. The chelator additive is particularly advantageous for increasing the OD of inks with a self-dispersing pigment colorant, and particularly the combination of such colorant with a multivalent cation additive.
Claims23
An inkjet ink comprising an aqueous vehicle and a chelator, wherein the chelator comprises a non-polymeric molecule having at least two coordinating nitrogen atoms and no carboxyl groups and wherein either a) the ink is substantially colorless or b) the ink further comprises a self-dispersing pigment colorant.
An inkjet ink set comprising a first inkjet ink and a second inkjet ink, wherein the first inkjet ink is a substantially colorless inkjet ink comprising an aqueous vehicle and a chelator, wherein the chelator comprises a non-polymeric molecule having at least two coordinating nitrogen atoms and no carboxyl groups, and the second inkjet ink is a colored ink comprising of an aqueous vehicle and pigment colorant.
An inkjet ink set comprising a at least three differently colored inkjet inks comprising, individually, a colorant stably dispersed or dissolved in an aqueous vehicle, wherein at least one of the three differently colored inkjet inks further comprises a chelator, wherein the chelator comprises a non-polymeric molecule having at least two coordinating nitrogen atoms and no carboxyl groups.
A method for ink jet printing onto a substrate, comprising the steps of:
- (a) providing an ink jet printer that is responsive to digital data signals;
- (b) loading the printer with a substrate to be printed;
- (c) loading the printer with an inkjet ink;
- and
- (d) printing onto the substrate using the inkjet ink in response to the digital data signals,
- wherein the inkjet ink comprises an aqueous vehicle and a chelator, wherein the chelator comprises a non-polymeric molecule having at least two coordinating nitrogen atoms and no carboxyl groups and wherein either a) the ink is substantially colorless or b) the ink further comprises a self-dispersing pigment colorant.
Dependencies are inferred from the claim text.