US5320668A
Expired / Lapsed
US
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Bleed alleviation using pH-sensitive agents
Assignee: HP Inc
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Filing: 1993-01-19
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Granted: 1994-06-14
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Expires: 2013-01-19
Abstract
Abstract Certain colorants become insoluble under specific and well-defined pH conditions. By forcing a colorant to become insoluble on the page, migration of the colorant is inhibited, thereby helping to reduce bleed between inks of different colors. The colorant is forced out of solution from the ink by contact with another ink having the appropriate pH (either higher or lower than that of the first ink). In particular, an ink containing a colorant comprising a pigment in combination with a pH sensitive dispersant is used in conjunction with an ink of the appropriate pH.
Inventors
- 👤 James P. Shields
- 👤 Raymond J. Adamic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:32
CPC Classifications
B; B41; B41M; B41M7/00; B41M7/0027; C; C09; C09D; C09D11/00; C09D11/30; C09D11/32; C09D11/324; C09D11/326; C09D11/328; C09D11/40; B41M5/00; B41M5/0011; B41M5/0017
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
63 words
A method of reducing bleed in printing at least two different colors on a print medium from an ink-jet pen, comprising printing a first ink containing a dispersed pigment, comprising a pigment in combination with a pH-sensitive dispersant, and printing a second ink having an appropriate pH to cause said dispersed pigment of said first ink to precipitate out on said print medium.
Claim 2
Independent Claim
63 words
A method of reducing bleed in printing at least two different colors on a print medium from an ink-jet pen, comprising printing a first ink containing a dispersed pigment, comprising a pigment in combination with a pH-sensitive dispersant, and printing a second ink having an appropriate pH to cause said dispersed pigment of said first ink to precipitate out on said print medium.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said second ink has a pH that is lower than that of said first ink.
Claim 4
Dependent Claim
33 words
The method of claim 2 wherein said pigment of said first ink is selected from the group consisting of carbon black, Pigment Black 7, Pigment Blue 15, Pigment Red 2, Disperse Red 17.
Claim 5
Dependent Claim
74 words
The method of claim 3 wherein said first ink comprises about 1 to 30 wt % solvent, 0 to about 15 wt % cosolvent, about 0.5 to 7 wt % carbon black, about 0.25 to 3.5 wt % dispersant, and the balance water and having a pH of about 8 to 10, and wherein said second ink includes at least one water-soluble dye and water and has a pH of about 3.6 to 5.6.
Claim 6
Dependent Claim
36 words
The method of claim 4 wherein said solvent is selected from the group consisting of glycols, diols, glycol esters, glycol ethers, long chain alcohols, esters, ketones, lactones, lactams, and glycerols, and derivatives thereof and mixtures thereof.
Claim 7
Dependent Claim
90 words
The method of claim 5 wherein said solvent is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, hydroxypivalyl hydroxypivalate, and derivatives thereof; butanediol, pentanediol, hexanediol, and homologous diols; propylene glycol laurate; ethylene glycol monobutyl ether, diethylene glycol mono ethyl ether, diethylene glycol mono butyl ether, diethylene glycol mono hexyl ether, propylene glycol ether, dipropylene glycol ether, and triethylene glycol ether; butyl alcohol, pentyl alcohol, and homologous alcohols; sulfolane, γ-butyrolactone, 2-pyrrolidone, 1-methyl-2-pyrrolidone, and 1-(2-hydroxyethyl)-2-pyrrolidone, and glycerols and their derivatives.
Claim 8
Dependent Claim
14 words
The method of claim 2 where said dispersant has at least one carboxyl group.
Claim 9
Dependent Claim
12 words
The method of claim 7 wherein said dispersant has multiple carboxyl groups.
Claim 10
Dependent Claim
18 words
The method of claim 2 where said dispersant is selected from the group of acrylic monomers and polymers.
Claim 11
Dependent Claim
79 words
The method of claim 4 wherein said first ink comprises about 5 wt % hydroxypivalyl hydroxypivalate, about 5 wt % ethoxylated glycerin, about 3.5 wt % carbon black, about 1.75 wt % dispersant, and the balance water and having a pH of about 8.5, and wherein said second ink comprises 5.5 wt % diethylene glycol, about 2 wt % Acid Yellow 23 dye, and the balance water and having a pH ranging from about 3.6 to less than 5.6.
Claim 12
Dependent Claim
21 words
The method of claim 1 wherein said second ink has a pH that is higher than that of said first ink.
Claim 13
Dependent Claim
95 words
A thermal ink-jet ink for printing at least two different colors on a print medium from an ink-jet pen, wherein a first ink has the following composition and pH: (a) about 1 to 30 wt % solvent, (b) 0 to about 15 wt % co-solvent, (c) about 0.5 to 7 wt % pigment, (d) about 0.25 to 3.5 wt % pH-sensitive dispersant, (e) the balance water, (f) pH of about 8 to 10, and wherein a second ink includes at least one water-soluble dye and water and has a pH of about 3.6 to 5.6.
Claim 14
Dependent Claim
95 words
A thermal ink-jet ink for printing at least two different colors on a print medium from an ink-jet pen, wherein a first ink has the following composition and pH: (a) about 1 to 30 wt % solvent, (b) 0 to about 15 wt % co-solvent, (c) about 0.5 to 7 wt % pigment, (d) about 0.25 to 3.5 wt % pH-sensitive dispersant, (e) the balance water, (f) pH of about 8 to 10, and wherein a second ink includes at least one water-soluble dye and water and has a pH of about 3.6 to 5.6.
Claim 15
Dependent Claim
35 words
The thermal ink-jet ink of claim 12 wherein said pigment of said first ink is selected from the group consisting of carbon black, Pigment Black 7, Pigment Blue 15, Pigment Red 2, Disperse Red 17.
Claim 16
Dependent Claim
38 words
The thermal ink-jet ink of claim 13 wherein said solvent is selected from the group consisting of glycols, diols, glycol esters, glycol ethers, long chain alcohols, esters, ketones, lactones, lactams, and glycerols, and derivatives thereof and mixtures thereof.
Claim 17
Dependent Claim
92 words
The thermal ink-jet ink of claim 14 wherein said solvent is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, hydroxypivalyl hydroxypivalate, and derivatives thereof; butanediol, pentanediol, hexanediol, and homologous diols; propylene glycol laurate; ethylene glycol monobutyl ether, diethylene glycol mono ethyl ether, diethylene glycol mono butyl ether, diethylene glycol mono hexyl ether, propylene glycol ether, dipropylene glycol ether, and triethylene glycol ether; butyl alcohol, pentyl alcohol, and homologous alcohols; sulfolane, γ-butyrolactone, 2-pyrrolidone, 1-methyl-2-pyrrolidone, and N-(2-hydroxyethyl)pyrrolidone, and glycerols and their derivatives.
Claim 18
Dependent Claim
93 words
The thermal ink-jet ink of claim 12 wherein said first ink has the following composition and pH: (a) about 5.0 wt % hydroxypivalyl hydroxypivalate, (b) about 5.0 wt % ethoxylated glycerin, (c) about 3.5 wt % carbon black, (d) about 1.75 wt % pH-sensitive dispersant, (e) the balance water, (f) pH of 8.5, and wherein said second ink has the following composition and pH: (a) about 5.5 wt % diethylene glycol, (b) about 2 wt % Acid Yellow 23 dye, (c) the balance water, (d) pH of about 3.6 to less than 5.6.
Claim 19
Dependent Claim
17 words
The ink of claim 12 wherein said pH-sensitive dispersant includes those having at least one carboxyl group.
Claim 20
Dependent Claim
13 words
The ink of claim 17 wherein said pH-sensitive dispersant has multiple carboxyl groups.
Claim 21
Dependent Claim
19 words
The ink of claim 12 wherein said pH-sensitive dispersant is selected from the group of acrylic monomers and polymers.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1997-06-13 | 1997-12-13 | 1998-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-13 | 2001-12-13 | 2002-06-14 | $3760.00 | Window Closed / Lapsed |
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