Ink jet inks having improved corrosion resistance for use in ink jet print heads comprising nickel or nickel alloys
View Patent ↗The present disclosure pertains to an aqueous ink jet ink having improved corrosion resistance for use in an ink jet print head including: (a) a colorant; (b) an aqueous vehicle; and (c) a certain random hydrophilic polymer additive, wherein the random hydrophilic polymer additive includes a random copolymer consisting of a hydrophilic component and an optional hydrophobic component, wherein the hydrophobic component includes a monomer selected from the group consisting of methyl acrylate and/or vinyl acetate and/or a hydrophobic monomer having a carbon to oxygen ratio of at least about 2.5, and wherein the hydrophobic component has a concentration of less than about 40% by weight, based on the weight of the polymer additive, and the hydrophilic component includes at least one non-acidic hydrophilic monomer having a carbon to oxygen ratio of less than about 2.5, and a monomer with an ionizable acidic group with a carbon to oxygen ratio of less than about 2.5 present in the amount of at least 10%, based on the weight of the polymer additive; and wherein the ink jet print head includes an ink flow passage, at least a portion of which is formed of nickel-containing metal such as nickel or nickel alloy.
1. An aqueous ink jet ink and an ink jet print head combination, wherein the ink jet ink comprises:
(a) a colorant;
(b) an aqueous vehicle; and
(c) a random hydrophilic copolymer additive, wherein the random hydrophilic copolymer additive comprises a random copolymer comprised of a hydrophilic component and an optional hydrophobic component, wherein the hydrophilic component comprises a monomer (X) having an ionizable acidic group and having a carbon to oxygen ratio of less than about 2.5, wherein said monomer (X) is present in the amount of more than 10%, based on the weight of the polymer additive, and at least one non-acidie hydrophilic monomer (Y) having a carbon to oxygen ratio of less than about 2.5, and the hydrophobic component comprises a monomer (Z) selected from the group consisting of methyl acrylate, vinyl acetate, a hydrophobic monomer (W) having a carbon to oxygen ratio of at least about 2,5, and mixtures thereof, and wherein the hydrophobic component has a concentration of from 0% to less than about 40% by weight, based on the weight of the polymer additive; and
wherein the ink jet print head comprises an ink flow passage, at least a portion of which is formed of a nickel-containing metal.
2. The ink jet ink/print head combination of claim 1 wherein the ionizable acidic group is selected from the group consisting of carboxylic acid, suifonic acid and phosphonic acid.
3. The ink jet ink/print head combination of claim 2 wherein the ionizable acid groups with a carbon to oxygen ratio of less than about 2.5 is selected from the group consisting of methacrylic acid, acrylic acid, maleic acid, maleic acid mono-methyl ester, maleic acid mono-ethyl ester, maleic acid mono-propyl ester, maleic acid mono-butyl ester, maleic acid mono-pentyl ester, maleic acid mono-hexyl ester, fumaric acid, fumaric acid mono methyl ester, fumaric acid mono-ethyl ester, fumaric acid mono-propyl ester, fumaric acid mono-butyl ester, fumaric acid mono-pentyl ester, fumaric acid mono-hexyl ester, itaconic acid, itaconic acid mono-methyl ester, itaconic acid mono-ethyl ester, itaconic acid mono-propyl ester, itaconic acid mono-butyl ester, itaconic acid mono-pentyl ester, crotonic acid, acryloyloxyethyl succinate, acrylamido-glycolic acid, acrylamido-propane sulfonic acid and acryiamido-methyl-propane sulfonic acid.
4. The ink jet ink/print head combination of claim 1 wherein the co orant is selected from the group consisting of a pigment dispersion, a self dispersible pigment, a dye, and mixtures thereof.
5. The ink jet ink/print head combination of claim 4 wherein the colorant is a pigment dispersion, a self dispersible pigment, or a mixture thereof.
6. The ink jet inkiprint head combination of claim 1 wherein the hydrophobic monomer (W) having a carbon to oxygen ratio of at least about 2.5 is selected from the group consisting of benzyl methacrylate, butyl methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, hexyl methacrylate, 2-ethythexyl methacrylate, octyl methacrylate, lauryl ethacrylate, stearyl methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, p-tolyl rnethaerylate, sorbyl tuethaerylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl aerylate, phenyl acrylate, phenoxyethyl aerylate, p-tolyl acrylate, sorbyl acrylate, styrene, alpha-methyl styrene, substituted styrenes, IN-alkyi aerylamides, N-alkyl methaerylamides, vinyl butyrate and vinyl benzoate.
7. The ink jet ink/print head combination of claim 1 wherein the hydrophilic monomer (Y) with carbon to oxygen ratio of less than about 2.5 is a non-ionic, non-acidic monomer selected from the group consisting of ethoxy triethyleneglycol methacrylate, (methoxy-ethoxy)ethyl acrylate, methoxy polyethylene glycol methacrylate, polyethylene glycol monomethacrylate, glycidyl methacrylate, glycidyl acrylate, hydroxyeth methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate.
8. The ink jet ink/print head combination of claim 7 wherein the hydrophilic monomer (Y) is ethoxy triethyleneglycol methacrylate, polyethylene glycol methacrylate, or hydroxyethyl methacrylate.
9. The ink jet ink/print head combination of claim 1 wherein the random hydrophilic copolymer additive has a number average molecular weight of about 1,000 to about 10,000.
10. The ink jet ink/print head combination of claim 1 wherein the random hydrophilic copolymer additive may be present in the amount of about 0.01 wt % to about 3 wt %, based on the total weight of ink.
11. The ink jet ink/print head combination of claim 1 wherein the random hydrophilic copolymer additive to pigment ratio is about 1:1 to about 1:40.
12. The ink jet ink/print head combination of claim 1 wherein the hydrophobic component has a concentration of less than about 15% by weight, based on the weight of the polymer additive,
13. The ink jet ink/print head combination of claim 1 wherein the ionizable acidic group is present in the amount of at least 20% by weight, based on the weight of polymer additive.
14. The ink jet ink/print head combination of claim 1 wherein the ink further comprises a vehicle comprised of water or a mixture of water and at least one water-soluble organic solvent (co-solvent).
15. The ink jet ink/print head combination of claim 1 wherein the hydrophobic component has a concentration of less than about 2% by weight, based on the weight of the polymer additive.
16. The ink jet ink/print head combination of claim 1 wherein the hydrophobic component has a concentration of about 0% by weight, based on the weight of the polymer additive.
17. The ink jet ink/print head combination of claim 1 wherein the ink jet ink has a current density at 400 mV of 100 μA per cm 2 or less.
18. An aqueous ink jet ink and an ink jet print head combination, wherein the ink jet ink comprises:
(a) a colorant;
(b) an aqueous vehicle; and
(c) a random hydrophilic copolymer additive, wherein the random hydrophilic copolymer additive comprises a random copolymer comprised of a hydrophilic component and optional hydrophobic component, wherein the hydrophobic component comprises a monomer (Z) selected from the group consisting of methyl acrylate, vinyl acetate, a hydrophobic monomer (NV) having a carbon to oxygen ratio of at least about 2.5, and mixtures thereof, and wherein the hydrophobic component has a concentration of from 0% to less than about 40% by weight, based on the weight of the polymer additive, and the hydrophilic component comprises at least one non-acidic hydrophilic monomer (Y) having a carbon to oxygen ratio of less than about 2.5, and a monomer (X) with an ionizable acidic group with a carbon to oxygen ratio of less than about 2.5 present in the amount of more than 10%, based on the weight of the polymer additive; and wherein the hydrophilic monomer (Y) having a carbon to oxygen ratio of less than about 2.5 has the following structure:
wherein n is an integer greater than about 0,
R a R b and R d are independently either H or alkyl, and
R c is alkyl; and
wherein the ink jet print head comprises an ink flow passage, at least a portion of which is formed of nickel-containing metal.
19. The ink jet ink/print head combination of claim 18 wherein n is about 1 to about 10.
20. The ink jet ink/print head combination of claim 18 wherein n is about 1 to about 4.
21. The ink jet ink/print head combination of claim 18 wherein the non-acidic hydrophilic monomer (Y) is selected from the group consisting of ethoxy triethyleneglycol methacrylate, (methoxy-ethoxy)ethyl acrylate, methoxy polyethylene glycol methacrylate, glycidyi methacrylate, and glycidyi acrylate.
22. An aqueous ink jet ink and an ink jet print head com)ination, wherein the ink jet ink comprises:
(a) a colorant;
(b) an aqueous vehicle; and
(c) a random hydrophilic polymer additive, wherein the random hydrophilic polymer additive is a random copolymer comprised of components A to C as follows:
A. more than 10 weight % of a hydrophilic monomer selected from the group consisting of monomers having an ionizable acidic group;
B. at least 25 weight % of a monomer or a combination of monomers selected from the group consisting of monomers of formula I:
wherein n is an integer greater than 0; R a , R b and R d are independently either H or alkyl, and R, is alkyl; and
C. 0-40 weight % of a hydrophobic monomer or combinations of such monomers;
wherein the total of monomers A B C is equal to 100 weight %, and the total of monomers A +B is 55-100 weight % (weight % of monomers is based on the weight of the polymer additive).
23. The ink jet ink/print head combination of claim 22 wherein the weight ratio of monomer B:A is in the range of about 1:1 to about 10:1.
24. The ink jet ink/print head combination of claim 22 or 23 , wherein monomers A and C are acrylic or methacrylic monomers.