EP0463737A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Use of ink formulations comprising mixtures of anionic waterfast dyes containing two or more carboxyl groups in thermal ink-jet printers to reduce nozzle clogging of the printer
Assignee: HP Inc
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Filing: 1991-05-29
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Granted: —
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Expires: 2011-05-29
Abstract
Abstract Inks are provided comprising (a) at least two dyes corresponding to the formula wherein W is COOH, X is H, or COOH, Y is H, COOH, or SO₃H, Z is H, COOH, or SO₃H, and R is H, CH₂COOH, or CH₂CH₂COOH; with the proviso that there are at least two COOH groups and that the number of COOH groups is equal to or greater than the number of SO₃H groups, and (b) a solvent which may be water or a mixture of water and a water-soluble organic solvent provide excellent waterfast prints on paper. The inks preferably have a pH from about 7 to about 9.5. Also preferably, a phosphate is added to reduce kogation and a metal chelating agent is added to further reduce nozzle clogging.
Inventors
- 👤 Garold E. Radke
- 👤 Suraj L. Hindagolla
- 👤 Raymond J. Adamic
- 👤 Palitha Wickramanayake
- 👤 David J. Halko
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 00:20
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/30; C09D11/32; C09D11/328
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
101 words
An ink comprising, by wt%: a) from about 0.5% to about 20% of at least two dyes, each of which, in the free acid state, independently corresponds to the formula wherein W is COOH, X is H or COOH, Y is K, COOH, or SO₃H, Z is H, COOH, or SO₃H, and R is H, CH₂COOH or CH₂CH₂COOH; provided that there are at least two COOH groups and that the number of COOH groups is equal to or greater than the number of SO₃H groups, b) up to about 30% of a water-soluble organic solvent for said dye, and c) water.
Claim 2
Dependent Claim
21 words
An ink according to claim 1 wherein each dye comprises at least about 10% by weight of the total dye concentration.
Claim 3
Dependent Claim
23 words
An ink according to claim 1 or 2 wherein two dyes are present in a ratio of from 15:85 to 70:30 by weight.
Claim 4
Dependent Claim
19 words
An ink according to claim 3 wherein said two dyes are present in a ratio of 50:50 by weight.
Claim 5
Dependent Claim
59 words
An ink according to any of claims 1 to 4 wherein: (a) in the first dye, W and X are COOH, Y and R are H, and Z is SO₃H, and (b) in the second dye, W and X are COOH, and either Y, Z and R are H or Y is SO₃H and Z and R are H.
Claim 6
Dependent Claim
29 words
An ink according to any of claims 1 to 5 wherein the dyes are present in the form of their alkali metal salts or ammonium or substituted ammonium salts.
Claim 7
Dependent Claim
28 words
An ink according to claim 6 wherein the alkali metal is Na, K or Li, and the ammonium or substituted ammonium is NH₄, (CH₃)₄N, (CH₃)₃NH, (CH₃)₂NH₂ or CH₃NH₃.
Claim 8
Dependent Claim
18 words
An ink according to any of claims 1 to 7 having a pH of from 7 to 9.5.
Claim 9
Dependent Claim
17 words
An ink according to claim 8 comprising a buffer to maintain said pH at 7 to 9.5.
Claim 10
Dependent Claim
38 words
An ink according to any of claims 1 to 9 which comprises (a) from 1 to 10% by weight of said at least two dyes, and (b) from 2 to 30% by weight of said water-soluble organic solvent.
Claim 11
Dependent Claim
63 words
An ink of any of claims 1 to 10 wherein the water-soluble organic solvent is an alkanol having from 1 to 4 carbon atoms, an amide, a ketone, a ketone alcohol, an ether, a nitrogen containing heterocyclic ketone, a polyalkylene glycol, an alkylene glycol, an alkylene thioglycol, thiodiglycol, hexylene glycol, diethylene glycol, a polyol, and a lower alkyl ether of a polyhydric alcohol.
Claim 12
Dependent Claim
15 words
An ink according to claim 11 wherein the organic solvent is diethylene glycol or 2-pyrrolidone.
Claim 13
Dependent Claim
36 words
An ink according to any of claims 1 to 12, additionally containing from 0.005 to 0.5% by weight of a monobasic or dibasic phosphate, and from 0.01 to 0.5% by weight of a metal chelating agent.
Claim 14
Dependent Claim
23 words
An ink according to claim 13 wherein the metal chelating agent is ethylenediaminetetraacetic acid, present in an amount of about 0.1% by weight.
Claim 15
Dependent Claim
97 words
An ink according to claim 14 and consisting essentially of: (a) about 1.1 wt% of a first dye in which W and X are COOH, Y and R are H, and Z is SO₃H, and a second dye in which W and X are COOH, and Y, Z and R are H; (b) about 7.5 wt% of 2-pyrrolidone; (c) about 0.2 wt% of sodium borate decahydrate and 0.2 wt% of tris[hydroxymethyl]aminomethane; (d) about 0.07 wt% of phosphate anion; (e) about 0.1 wt% of ethylenediaminetetraacetic acid; (f) about 0.3 wt% of a biocide; and (g) the balance water.
References Cited (Backward Citations)
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