Ink to ink bleed and halo control using specific polymers in ink-jet printing inks
AssigneeHewlett-Packard Company
InventorDennis P. Parazak
Life of this patent
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Abstract
The ink set of this invention comprises at least two inks, one of which contains a pH sensitive polymer and preferably a self-dispersing pigment colorant. A second ink is provided which comprises incompatible inorganic or organic salts or has an appropriate pH. The polymer precipitates onto a medium upon contact with the second ink, thereby providing improved bleed and halo control.
Claims27
An ink-jet ink set for inkjet printing comprising a first ink and a second ink, wherein said first ink comprises at least one pH-sensitive polymer and a self-dispersing pigment and wherein said second ink comprises a multi-valent salt or has an appropriate pH, such that when said first ink and said second ink contact on a print medium, said polymer in said first ink will precipitate onto said print medium;
- and wherein said polymer comprises monomers having the structure:
- wherein R1 are independently selected from H or a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain, optionally containing halogen, ester, ether, amine or amide functionalities;
- R2 is a group selected from the group consisting of a moiety containing a carboxylic acid group, primary amine, secondary amine, tertiary amine, or mixtures thereof;
- and R3 is a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain, optionally containing ester, ether, amine or amide functionalities, said monomer present in an amount sufficient to provide a stable polymer when solubilized in water, yet will precipitate upon contact with said second ink, and providing that at least one monomer must be N-octylacrylamide, at least one monomer is a basic amine group, and one monomer is an acid group, wherein said polymer an acid number within a range of a 80-200 mgKOH/g of polymer.
A method of reducing bleed and halo between at least two different inks on a print medium, said at least two different inks comprising a first ink composition and a second ink composition;
- said method comprising the steps of:
- a) formulating said first ink to comprise a pH-sensitive polymer and a self-dispersing pigment, wherein said polymer comprises monomers having the following basic structure:
- wherein R1 are independently selected from H or a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain, optionally containing halogen, ester, ether, amine or amide functionalities;
- R2 is a group selected from the group consisting of a moiety containing a carboxylic acid group, primary amine, secondary amine, tertiary amine, or mixtures thereof;
- and R3 is a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain, optionally containing ester, ether, amine or amide functionalities, and providing that at least one N-octylacrylamide monomer, one basic amine group and one acid group are present, wherein said polymer has an acid number within a range of bout 80-200 mgKOH/g of polymer;
- and
- b) formulating said second ink to comprise a sufficient amount of a multi-valent salt which is incompatible with said pH-sensitive polymer or a sufficient amount of an organic acid such that said second ink has an appropriate pH such that when printed on a print medium and said inks come into contact, said polymer in said first ink will precipitate onto said print medium to effect a reduction in migration of said first ink into said second ink, thereby reducing bleed and halo between said at least two inks.
Dependencies are inferred from the claim text.