JP2015168763A - Ink composition, inkjet recording method, and colored body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous ink composition for inkjet printing, which can improve water resistance of an image.SOLUTION: An ink composition giving high water resistance and a neutral gray to black hue is provided, which comprises at least a dye represented by formula (1) or its salt or its mixture, and a red dye having a specific structure, a yellow dye, and an orange dye. In formula (1), R, R, and Rto Reach independently represent a H atom, sulfo group, nitro group, carboxyl group, cyano group, halogen atom, hydroxy group, sulfamoyl group, or alkyl group, alkoxy group, alkylsulfonyl group, arylsulfamoyl amino group which may have a substituent, or the like; Rand Reach independently represent a H atom, sulfo group, halogen atom, cyano group, carboxy group, nitro group, or alkoxy group or alkyl group which may have a substituent; and n is 0 or 1.

Description

  The present invention relates to an aqueous black ink composition, an ink jet recording method using the same, and a colored body.

  An ink jet recording method, which is one of color recording methods, is a method of recording by generating ink droplets and attaching them to various recording materials (paper, film, fabric, etc.). This method is quiet because it does not generate sound because the recording head and the recording material are not in direct contact with each other. In addition, it has been spreading rapidly in recent years due to the feature of being easy to downsize and speed up, and is expected to grow greatly in the future.

Due to the recent development of ink-jet related technology, the recording speed in ink-jet recording (printing) is remarkably improved. For this reason, inkjet recording has been spreading not only for home use but also in commercial printing and offices.
Black ink used for inkjet recording is an important ink used for both mono-color and full-color images. However, there are many technical difficulties in developing pigments that are neutral in hue and light color gamut, high in color density, and excellent in fastness. There are few things with sufficient performance. Therefore, generally, a black ink is prepared by mixing a plurality of various pigments. However, when an ink is prepared by mixing a plurality of dyes, there are problems such as 1) the hue differs depending on the recording material, and 2) the discoloration is increased due to water, compared to the case where the ink is prepared using a single dye. It is easy to happen.
It is known that the above “discoloration” can generally be evaluated separately as two different indicators. One is evaluated as a change in print density using “fading” as an index. The other one uses “discoloration” as an index and is evaluated as a change in hue (ΔE). Among these, the latter “discoloration” is remarkably observed in inks prepared from a plurality of pigments, and is visually perceived as a marked deterioration of the recorded image, so that there is a strong demand for improvement.

  As a black ink in which a plurality of various pigments are mixed, for example, a black ink composition of Patent Document 1 has been proposed.

  In addition, the dye represented by the following formula (1) described in this specification is represented by Patent Documents 2 to 5, and the dye represented by the following Formula (2) is represented by Patent Document 6 and the following Formula (3). The dyes to be used are described in Patent Document 7, respectively.

Japanese Patent No. 3178200 International Publication 2006/051850 Pamphlet International Publication No. 2013/035560 Pamphlet JP 2008-69331 A JP 2013-32469 A Japanese translation of PCT publication No. 2004-83892 JP 2005-68416 A

  An object of the present invention is to provide a water-based ink composition that exhibits a neutral gray to black hue and is excellent in water resistance of a recorded image.

    As a result of intensive studies to solve the above-described problems, the present inventors have found that the above-described problems can be solved by the aqueous ink composition having the specific configuration described below, and have completed the present invention.

That is, the present invention relates to the following (1) to (10).
(1)
An ink composition containing at least a dye represented by the following formula (1) or a salt thereof or a mixture thereof, and a dye represented by the following formula (2) or a salt thereof or a mixture thereof.

(In the above formula (1),
R ₁ , R ₂ , R ₅ , R ₆ and R ₇ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxy group, a carboxy group, a sulfo group, a sulfamoyl group, a nitro group, or a substituent. Represents a group selected from the group consisting of an alkoxy group which may have a substituent, an alkylsulfonyl group which may have a substituent, an alkyl group, an arylsulfamoylamino group which may have a substituent, and an alkylcarbonylamino group .
R ₃ and R ₄ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a cyano group, a sulfo group, a carboxy group, a nitro group, an optionally substituted alkoxy group, and an alkyl group. Represents a group.
n represents 0 or 1. )

(In the above formula (2),
X and Y each independently represent a group selected from the group consisting of a substituted or unsubstituted amino group, an alkoxy group, a hydroxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted aryloxy group,
B represents a carbonyl group or a sulfonyl group,
q represents an integer of 0 to 2,
R ₁₁ represents a substituted or unsubstituted phenyl group, an alkyl group, a phenacyl group, or a phenoxymethylcarbonyl group, and A represents a hydrogen atom or a substituent. )
(2)
Furthermore, the ink composition according to the above (1), further comprising at least one kind of dye selected from a yellow dye and an orange dye.
(3)
The yellow dye is C.I. I. The ink composition according to the above (2), which is a pigment selected from Direct Yellow 86 and 132.
(4)
The orange dye is C.I. I. The ink composition according to the above (2), which is a dye selected from Direct Orange 39 and a dye represented by the following formula (3), a salt thereof, or a mixture thereof.

(In said formula (3), Q represents the integer of 1-3.)
(5)
Furthermore, the ink composition as described in any one of (1) to (4) above, which contains at least one water-soluble organic solvent.
(6)
The ink composition according to any one of (1) to (5), which is used for inkjet recording.
(7)
An ink jet recording method in which recording is performed by ejecting droplets of the ink composition according to any one of (1) to (6) according to a recording signal and attaching the droplets to a recording material.
(8)
The inkjet recording method according to (7), wherein the recording material is an information transmission sheet.
(9)
The colored body colored with the ink composition as described in any one of said (1)-(6).
(10)
An inkjet printer loaded with a container containing the ink composition according to any one of (1) to (6) above.

  According to the present invention, a water-based ink composition that exhibits a neutral gray to black hue and is excellent in water resistance of a recorded image can be provided.

The present invention is described in detail below. In the present specification, “%” and “parts”, including examples and the like, are described on a mass basis unless otherwise specified. In the present specification, “CI” means “color index”.
In the present specification, unless otherwise specified, “pigment or a salt thereof or a mixture thereof” is simply described as “pigment”.

  The ink composition is water-based and substantially a solution-based water-based ink composition.

The dye represented by the above formula (1) is a water-soluble black dye.
In the above formula (1), R ₁ , R ₂ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, a halogen atom, a cyano group, a hydroxy group, a carboxy group, a sulfo group, a sulfamoyl group, or a nitro group. , An alkoxy group which may have a substituent, an alkylsulfonyl group which may have a substituent, an alkyl group, an arylsulfamoylamino group which may have a substituent, and an alkylcarbonylamino group Represents a group selected from:
R ₃ and R ₄ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a cyano group, a sulfo group, a carboxy group, a nitro group, an alkoxy group that may have a substituent, and an alkyl group. Represents a group.

  Examples of the alkoxy group which may have the above-described substituent include an alkoxy group in which the alkoxy moiety is linear, branched or cyclic. Among them, an alkoxy group that may have a sulfo group is preferable, a C1-C6 alkoxy group that may have a sulfo group is more preferable, and a C1-C4 alkoxy group that may have a sulfo group is more preferable. .

  Examples of the alkylsulfonyl group that may have a substituent include alkylsulfonyl groups in which the alkyl moiety is linear, branched or cyclic. Especially, the alkylsulfonyl group which may have a hydroxy group is mentioned preferably, the C1-C6 alkylsulfonyl group which may have a hydroxy group is more preferable, and the C1-C4 alkylsulfonyl group which may have a hydroxy group Is more preferable.

As said alkyl group, a linear, branched or cyclic alkyl group is mentioned, A linear or branched thing is preferable and a linear thing is more preferable.
Specific examples thereof include linear C1-C6 alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl and n-hexyl; isopropyl, isobutyl, sec-butyl, t-butyl, isopentyl and isohexyl. Branched C1-C6 alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like cyclic C1-C6 alkyl groups; and the like.

  Examples of the arylsulfamoylamino group which may have a substituent include a phenylsulfamoylamino group which may have a substituent, and a phenylsulfamoylamino group which may have an alkyl group. Groups are preferred. Examples of the alkyl group include the same alkyl groups as those described above including preferable ones.

  Examples of the alkylcarbonylamino group include an alkylcarbonylamino group having the same alkyl group as the alkyl group, including those preferable for the alkyl group.

  As said halogen atom, a chlorine atom, a bromine atom, or an iodine atom is mentioned, A chlorine atom or a bromine atom is preferable, and a chlorine atom is more preferable.

Among the above, as R ₁ and R ₂ ,
At least one is preferably a group other than a hydrogen atom,
More preferably, at least one is a carboxy group, a sulfo group or an unsubstituted alkoxy group, and the other is a hydrogen atom or a sulfo group,
More preferably, one is a sulfo group and the other is a hydrogen atom.
Among these, “one” is preferably R ₁ and “the other” is preferably R ₂ .

Of the above, as R ₅ , R ₆ and R ₇ ,
At least one of them is preferably a group other than a hydrogen atom,
A group in which at least one of them is selected from a carboxy group, a sulfo group, and a nitro group is more preferable,
More preferably, at least one is a hydrogen atom and one of the remaining two is a carboxy group, a sulfo group, or a nitro group, and the other is a hydrogen atom or a nitro group,
It is particularly preferable that at least one is a hydrogen atom and one of the remaining two is a sulfo group and the other is a hydrogen atom or a nitro group.
Of these, “of one of the remaining two” is preferably R ₆ and “the other” is preferably R ₅ .

Among the above, as R ₃ and R ₄ ,
At least one is preferably a group other than a hydrogen atom,
More preferably, at least one is a sulfo group, an alkoxy group which may have a substituent, or an alkyl group, and the other is a hydrogen atom, a sulfo group or an alkyl group,
More preferably, at least one is a sulfo group, the other is a hydrogen atom, or one is an alkoxy group which may have a substituent, and the other is an alkyl group,
One is particularly preferably a sulfo group and the other a hydrogen atom.
Among the above, it is preferable that “one” is R _{3 and} “the other” is R ₄ .

In the above formula (1), examples of the substitution position of the nitro group, R _{1 to} R ₇ , and — (SO ₃ H) n group whose substitution positions are not specified include the following positions.

[Substitution positions of R ₁ , nitro group, and R ₂ ]
As for the substitution position of each group on the benzene ring substituted by these, the substitution positions of the following (a) to (c) are exemplified with the substitution position of the azo group bonded to the benzene ring as the first position.
(A) R ₁ is in position 2, the nitro group is in position 4, and R ₂ is in position 5.
(B) R ₁ is 4-position, nitro group is 2-position, and R ₂ is 5-position.
(C) R ₁ is in position 2, the nitro group is in position 5, and R ₂ is in position 4.
Of these, (a) or (b) is preferred, and (a) is more preferred.

[Substitution positions of R ₃ and R ₄ ]
The substitution position of each group on the benzene ring to which these are substituted is such that R ₃ is the 3-position, with the substitution position of the azo group binding to the benzene ring and binding to the benzene ring having R _{5 to} R ₇ as the 1-position. R ₄ is preferably substituted at the 6-position.

[Substitution positions of R ₅ , R ₆ and R ₇ ]
As for the substitution position of each group on the benzene ring substituted by these, the substitution positions of the following (a) to (c) are exemplified with the substitution position of the azo group bonded to the benzene ring as the first position.
(A) R ₅ is 2nd, R ₆ is 4th, and R ₇ is 5th.
(B) R ₅ is 3rd, R ₆ is 5th, and R ₇ is 4th.
(C) R ₅ is 2nd, R ₆ is 5th, R ₇ is 4th.
(D) R ₅ is 3rd, R ₆ is 4th, and R ₇ is 6th.
Of these, (a) is preferred.

[Substitutional position of — (SO ₃ H) n group]
When the substitution position of the hydroxy group substituted on the naphthalene ring substituted by the — (SO ₃ H) n group is 1-position and the substitution position of the sulfo group whose substitution position is specified is the 3-position, the — (SO ₃ H) n group is Substitution at the 5-position is preferred.

Regarding the dye represented by the above formula (1), each group represented by R ₁ to R ₇ and each group whose substitution position including a nitro group and a “— (SO ₃ H) n group” is not specified As for the substitution position, a combination of preferable ones is more preferable, and a combination of more preferable ones is more preferable. The same applies to combinations of preferable ones and combinations of preferable ones and more preferable ones.

  Specific examples of the dye represented by the above formula (1) are listed in Tables 1 to 3 below. However, the compound represented by the above formula (1) is not limited thereto. In each table, ionic functional groups such as sulfo group and carboxy group in formula (1) are all described in the form of free acid.

  Among the dyes represented by the above formula (1), dyes represented by the following formula (22), formula (23) or formula (26) are particularly preferable, and among these, the formula (22) is most preferable. These dyes are particularly effective for color development, light resistance, ozone resistance and water resistance.

  The pigment | dye represented by the said Formula (1) is compoundable by the method of the said patent document 3, for example.

The dye represented by the above formula (2) is a water-soluble magenta dye.
In the above formula (2), examples of the substituted amino group in X and Y include an arylamino group, a pyridinium group, an aralkylamino group, a mono- or di-alkylamino group, a morpholin-4-yl group, an allylamino group, a diallylamino group, A quaternary ammonium group etc. are mentioned.
Examples of the arylamino group include a C6-C10 arylamino group, and a phenylamino group (anilino group), a naphthylamino group, and the like are preferable. Specific examples thereof include anilino; arylamino groups optionally having a C1-C8 alkyl group such as 2-methylanilino, 4-butylanilino, 4-octylanilino; 3-sulfoanilino, 4-sulfoanilino, 2,5- It consists of a sulfo group, a carboxy group, and a hydroxy group, such as disulfoanilino, 2-carboxyanilino, 3,5-dicarboxyanilino, 4-hydroxy-3-carboxyanilino, 4-hydroxy-5-carboxyanilino, etc. Arylamino group which may have a group selected from the group; and the like.
The pyridinium group is a group selected from the group consisting of a carboxy group, a C1-C4 alkyl group, a carbamoyl group, and a sulfo group, such as 3-carboxypyridinium, 4-methylpyridinium, 3-carbamoylpyridinium, and 4-sulfopyridinium. And a pyridinium group which may have
Examples of the aralkylamino group include a C6-C10 aryl C1-C4 alkylamino group. Specific examples thereof include C1-C4 alkyl groups such as benzylamino, 4-methylbenzylamino and 4-chlorobenzylamino, or aralkylamino groups which may have a halogen atom.
The mono- or dialkylamino group includes dimethylamino, ethylamino, n-propylamino, n-butylamino, n-pentylamino, n-hexylamino, cyclohexylamino, n-heptylamino, n-octylamino, 2-sulfo. Ethylamino, carboxymethylamino, di (carboxymethyl) amino, 1,2-dicarboxypropylamino, 2-hydroxyethylamino, di (2-hydroxyethyl) amino, 2-hydroxypropylamino, 2-hydroxyethoxyethylamino Linear, branched, or cyclic mono- or di-C1-C8 alkyl, which may have a substituent selected from the group consisting of a sulfo group, a carboxy group, a hydroxy group, and a C1-C4 alkoxy group, An amino group is mentioned.
Examples of the quaternary ammonium group include quaternary ammonium groups having a C1-C8 alkyl group, such as trimethylammonium, triethylammonium, and quaternary ammonium of 1,4-diazabicyclo- (2,2,2) -octane.

Examples of the alkoxy group in X and Y include C1-C8, preferably C1-C6, and more preferably a C1-C4 alkoxy group.
Specific examples thereof include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, t-butoxy, n-pentoxy, n-hexyloxy, n-heptyloxy, n-octyloxy and the like. A linear or branched alkoxy group is mentioned.

Examples of the substituted thio group include a C1-C6 alkylthio group which may have a group selected from the group consisting of a hydroxy group, a cyano group, an alkoxy group, a hydroxyalkoxy group, a sulfo group, and a carboxy group.
In the present specification, the unsubstituted thio group means a group represented by “HS—”.

The aryloxy group in the substituted or unsubstituted aryloxy group includes a C6-C10 aryloxy group, preferably a phenoxy group and a naphthyloxy group, and more preferably the former.
Specific examples thereof include a group selected from the group consisting of a carboxy group, a C1-C4 alkyl group, and a sulfo group, such as phenoxy, 2-carboxyphenoxy, 4-carboxyphenoxy, 3-methylphenoxy, and 4-sulfophenoxy. A C6-C10 aryloxy group which may have

  Among the above, as X and Y, morpholino, hydroxy, 2-methylanilino, 3-sulfoanilino, 3,5-dicarboxyanilino, 4-hydroxy-5-carboxyanilino, 3-carboxypyridinium, carboxymethylamino, Preferred is a group selected from di (carboxymethyl) amino, phenoxy, 2-carboxyphenoxy, sulfopropylthio, sulfoethylamino, hydroxy, 3,5-dicarboxyanilino, 4-hydroxy-5-carboxyanilino, A group selected from sulfopropylthio and sulfoethylamino is more preferable.

Examples of the substituted phenyl group for R ₁₁ include a phenyl group which may have a C1-C4 alkyl group. Examples of the C1-C4 alkyl group include a linear, branched, or cyclic alkyl group. Specific examples thereof include alkyl groups such as straight chain such as methyl, ethyl, n-propyl and n-butyl; branched chain such as isopropyl, isobutyl, sec-butyl and t-butyl; cyclic such as cyclopropyl and cyclobutyl. .
Of the above, R ₁₁ is preferably an unsubstituted phenyl group.

A represents a hydrogen atom or a substituent, and is preferably a substituent. The substituent is preferably a group selected from the group consisting of a sulfo group and a carboxy group, and more preferably a sulfo group.
Although the substitution position of A is not particularly limited, it is preferable to substitute the 4-position and / or the 6-position with the substitution position of the amino group bonded to the benzene ring substituted by A as the 1-position and the substitution position of the azo group as the 3-position. More preferred is substitution at the 4-position.

  Q representing the number of substitutions of A is generally an integer of 0 to 2, preferably 1 or 2, and more preferably 1.

  In the above formula (2), the substitution position of the sulfo group whose substitution position is not specified is not particularly limited, but the substitution position of the amino group bonded to the naphthalene ring is the 1st position, and the substitution of the sulfo group whose substitution position is specified The position is 6-position, the substitution position of azo group is 7-position, and the substitution position of hydroxy group is 8-position. Substitution is preferably 3-position or 4-position, more preferably 4-position.

A particularly preferred dye as the above formula (2) is a dye represented by the following formula (4).
The pigment | dye represented by the said Formula (2) is compoundable according to the method of the said patent document 6, for example.

  The ink composition may further contain at least one dye selected from yellow dyes and orange dyes in addition to the dyes represented by the formulas (1) and (2). By further containing these pigments, in addition to water resistance, the hue can be further improved from neutral gray to black.

  Examples of the yellow dye include C.I. I. And a dye selected from Direct Yellow 86 and 132. Any of these dyes is preferable.

Examples of the orange dye include C.I. I. Direct orange 39 and the pigment | dye represented by the said Formula (3) are mentioned. Of these, the latter is preferred.
The pigment | dye represented by the said Formula (3) is compoundable according to the method of patent document 7, for example. The pigment | dye obtained by a synthesis | combination is a mixture of the pigment | dye represented by the integer whose Q in the said Formula (3) is 1-3. This mixture of dyes can be purified to give a single compound, but can also be used as a mixture.

The above-mentioned ink composition may further contain a coloring matter other than those described above within a range not hindering the effect obtained by the present invention for the purpose of finely adjusting the hue to a desired hue.
As such a pigment, a reactive dye, an acid dye or a direct dye is preferably exemplified, and a direct dye is preferable.

  Specific examples of reactive dyes include C.I. I. Yellow dyes such as Reactive Yellow 2, 3, 18, 81, 84, 85, 95, 99, 102; I. And orange dyes such as Reactive Orange 5, 9, 12, 13, 35, 45, 99;

  Specific examples of the acid dye include C.I. I. Acid Yellow 1, 3, 11, 17, 18, 19, 23, 25, 36, 38, 40, 40: 1, 42, 44, 49, 59, 59: 1, 61, 65, 72, 73, 79, Yellow dyes such as 99, 104, 110, 159, 169, 176, 184, 193, 200, 204, 207, 215, 219, 219: 1, 220, 230, 232, 235, 241, 242, 246; C. I. Acid Orange 3, 7, 8, 10, 19, 24, 51, 56, 67, 74, 80, 86, 87, 88, 89, 94, 95, 107, 108, 116, 122, 127, 140, 142, 144, 149, 152, 156, 162, 166, 168, etc. Orange dyes;

  Specific examples of the direct dye include C.I. I. Yellow dyes such as Direct Yellow 8, 11, 12, 21, 28, 33, 39, 44, 49, 50, 85, 87, 88, 89, 98, 100, 110, 142, 144, 146; I. And orange dyes such as Direct Orange 17, 26, 102, and the like.

  Among the above dyes, C.I. I. Direct Yellow 142, and C.I. I. Direct Orange 17 is preferred.

All the dyes mentioned above can be used as salts.
Examples of the salt of the dye include salts formed with inorganic or organic cations. Among them, specific examples of inorganic salts include salts formed with cations of elements of Group 1 or Group 2 of the periodic table of elements, and ammonium salts. Among these, preferred inorganic salts are lithium, sodium, potassium and ammonium salts.
Examples of the organic cation salt include, but are not limited to, salts formed with the compound represented by the following formula (16).

In the above formula (16), Z ₁ , Z ₂ , Z ₃ and Z ₄ each independently represent a hydrogen atom, an alkyl group, a hydroxyalkyl group or a hydroxyalkoxyalkyl group, but Z ₁ , Z ₂ , Z All of ₃ and Z ₄ are not hydrogen atoms.

As the alkyl group of Z ₁ , Z ₂ , Z ₃ and Z _{4 in} the formula (16), a C1-C4 alkyl group is preferable, and specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec -Butyl, t-butyl and the like.
Examples of hydroxyalkyl groups include hydroxy-C1-C4 alkyl groups such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl and the like.
Examples of hydroxyalkoxyalkyl groups include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl, etc. A hydroxy C1-C4 alkoxy-C1-C4 alkyl group is mentioned, Among these, a hydroxyethoxy-C1-C4 alkyl group is preferable. Particularly preferred are hydrogen atoms; methyl; hydroxy-C1-C4 alkyl groups such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl; Hydroxyethoxy-C1-C4 alkyl groups such as hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl, etc. Can be mentioned.

Specific examples of Z ₁ , Z ₂ , Z ₃ and Z _{4 in} the formula (16) are shown in the following Table 4, but the compound represented by the formula (16) is not limited to these specific examples.

  Preferred examples of the organic cation salt include monoethanolamine salts, diethanolamine salts, triethanolamine salts, monoisopropanolamine salts, diisopropanolamine salts, and triisopropanolamine salts.

  When the above-mentioned various dyes are used in ink jet recording, it is preferable to remove inorganic impurities mixed in when they are generally obtained as commercial products by a refining operation. Examples of such a purification operation include a purification method using a reverse osmosis membrane; or a purification method in which the chromogen is stirred in a mixed solvent of alcohol such as methanol and water, separated by filtration, and dried. Examples of inorganic impurities include chlorides (for example, sodium chloride) and sulfides (for example, sodium sulfate) of Group 1 and / or Group 2 elements of the periodic table of elements. When purification is performed, the total content of inorganic impurities in the total mass of the water-based ink composition is preferably 100 ppm or less, and more preferably 50 ppm or less. The lower limit may be equal to or lower than the detection limit of the detection device, that is, 0%.

The ink composition is prepared using water as a medium, and may contain an ink preparation agent as needed within a range that does not impair the effects of the present invention.
Examples of ink preparation agents include water-soluble organic solvents, preservatives, antifungal agents, pH adjusters, chelating reagents, rust inhibitors, water-soluble ultraviolet absorbers, water-soluble polymer compounds, dye solubilizers, antioxidants, Surfactant etc. are mentioned.

Examples of the water-soluble organic solvent include C1-C4 alkanols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol and tert-butanol, N, N-dimethylformamide, N, N-dimethylacetamide and the like. Carboxylic acid amide, 2-pyrrolidone, lactam such as N-methylpyrrolidin-2-one, and cyclic urea such as 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido-2-one , Ketones such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one or cyclic ethers such as keto alcohol, tetrahydrofuran, dioxane, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butyle (C2-C6 such as glycol, 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol, dithiodiglycol, etc. ) Monomer having an alkylene unit, oligomer or polyalkylene glycol or thioglycol, polyol (triol) such as glycerin, hexane-1,2,6-triol, ethylene glycol monomethyl ether or ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol Monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol) or triethyl Glycol monomethyl ether or polyhydric alcohol (C1 -C4) alkyl ethers such as triethylene glycol monoethyl ether, gamma-butyrolactone or dimethyl sulfoxide. Among these water-soluble organic solvents, 2-pyrrolidone, isopropyl alcohol, glycerin, diglycerin, butyl carbitol, ethylene glycol, diethylene glycol, and propylene glycol are preferable, and 2-pyrrolidone, isopropyl alcohol, glycerin, and butyl are more preferable. And carbitol. These water-soluble organic solvents can be used alone or in combination of two or more.
The content of the water-soluble organic solvent is usually 0 to 50% by mass, preferably 25 to 50% by mass, based on the total mass of the aqueous ink composition. When the ink composition is used as an inkjet ink, it preferably contains at least one water-soluble organic solvent.

  Examples of the preservative include organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, (double) nitrile, pyridine, 8-oxyquinoline, Benzothiazole, isothiazoline, dithiol, pyridine oxyd, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone , Benzyl bromacetate compounds, inorganic salt compounds and the like. Examples of the organic halogen compound include sodium pentachlorophenol, examples of the pyridine oxido compound include sodium 2-pyridinethiol-1-oxide, and examples of the inorganic salt compound include anhydrous sodium acetate. Examples of the isothiazoline-based compound include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 5 -Chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride, etc. Can be mentioned.

Examples of the antifungal agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one and salts thereof.
Other antiseptic / antifungal agents include sodium sorbate and sodium benzoate.
The total content of the antiseptic and / or antifungal agent is preferably 0.02 to 1%.

  As the pH adjuster, any substance can be used as long as it can control the pH of the ink within a range of usually 5 to 12, preferably 7 to 12, more preferably 7 to 10 without adversely affecting the ink to be prepared. Can be used. Examples include alkanolamines such as diethanolamine, triethanolamine, N-methyldiethanolamine, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide (ammonia), or lithium carbonate. And alkali metal carbonates such as sodium carbonate, sodium hydrogen carbonate and potassium carbonate, and inorganic bases such as potassium acetate, sodium silicate and disodium phosphate.

  Examples of chelating reagents include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate, and the like.

  Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

  Examples of the water-soluble ultraviolet absorber include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

  Examples of the water-soluble polymer compound include polyvinyl alcohol, cellulose derivatives, polyamines and polyimines.

  Examples of the dye solubilizer include ε-caprolactam, ethylene carbonate, urea and the like. Of these, urea is preferred.

  As the antioxidant, for example, various organic and metal complex antifading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, and the like.

Examples of the surfactant include known surfactants such as anions, cations, and nonions.
Examples of anionic surfactants include alkyl sulfonates, alkyl carboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurate, alkyl sulfate poly Oxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkyl allyl sulfone hydrochloride, diethyl sulfo Examples thereof include oxalate, diethyl hexyl sulfosuccinate, dioctyl sulfosuccinate and the like.
Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.
Examples of amphoteric surfactants include lauryl dimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and other imidazoline derivatives. Can be mentioned.
Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, polyoxyallylalkyl. Ethers such as alkyl ethers, polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate Ester, polyoxyethylene stearate and the like, 2,4,7,9-tetramethyl-5-decyne-4,7-dioe Acetylene glycols such as 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3ol (for example, Surfinol 104, 105, 82 manufactured by Nissin Chemical Co., Ltd.) 420, 440, 465, Olfin STG, etc.).
Among these, Surfynol 420, 440 and 465 are preferable, and Surfynol 440 is more preferable.

In the production of the ink composition, there is no particular limitation on the order in which the coloring matter and various ink preparation agents used as necessary are dissolved. The water used for preparing the ink composition is preferably water with few impurities such as ion exchange water and distilled water.
In addition, if necessary, after the aqueous ink composition is prepared, microfiltration using a membrane filter or the like can be performed to remove impurities in the ink composition. In particular, when the ink composition is used for ink jet recording, it is preferable to perform microfiltration. The pore size of the filter used for microfiltration is usually 1 to 0.1 μm, preferably 0.8 to 0.1 μm.

The surface tension of the ink composition is usually 25 to 70 mN / m, preferably 25 to 60 mN / m.
Similarly, the viscosity is usually 30 mPa · s or less, preferably 20 mPa · s or less.

  The ink composition can be used in various fields. As an example, it can be used for writing, water-based printing, information recording, and the like, and is particularly preferably used for inkjet recording.

When performing the ink jet recording, an ink jet printer is generally used. There are no particular restrictions on the ink nozzles, ink ejection methods, and the like provided in the ink jet printer, and they can be appropriately selected according to the purpose.
Examples of the ink ejection method include a charge control method; a drop-on-demand method (pressure pulse method); an acoustic ink jet method; a thermal ink jet method such as a bubble jet (registered trademark) method.
As a method of inkjet recording, a method called a photo ink or the like that ejects a large amount of ink with a small pigment content in a volume smaller than a normal discharge amount; substantially the same hue and a pigment content. Also included is a method for improving the image quality of a recorded image by discharging a plurality of different inks in combination; or a method for discharging a color ink and a colorless and transparent ink in combination.

The ink jet recording method is a method of performing recording by ejecting droplets of the ink composition according to a recording signal and attaching them to a recording material.
By using the above ink composition as a black ink and using each ink composition such as magenta, cyan, yellow, green, blue (or violet) and red (or orange) as necessary, a full color A recorded image can also be obtained. At this time, the ink composition of each color can be poured into each container, and the container can be loaded into a predetermined position of the ink jet printer and used for ink jet recording in the same manner as the container containing the ink composition. .

The colored body means a substance colored with the ink composition, and is preferably a substance colored by the inkjet recording method.
The substance is not particularly limited as long as it can be colored by the ink composition. Among such substances, recording materials such as information transmission sheets such as paper and film; fibers and fabrics (cellulose, nylon, wool, etc.); leather; base materials for color filters;
Examples of the information transmission sheet include those that have been surface-treated, specifically, those in which an ink receiving layer is provided on a substrate such as paper, synthetic paper, and film, and those in which an ink receiving layer is not particularly provided. It is done. The ink receiving layer is formed by, for example, impregnating or coating the above base material with a cationic polymer; a porous white inorganic substance capable of absorbing a pigment in an aqueous ink composition such as porous silica, alumina sol, or special ceramics; And coating with the hydrophilic polymer such as polyvinyl pyrrolidone on the surface of the substrate. A sheet provided with such an ink receiving layer is usually called ink jet dedicated paper (film), glossy paper (film) or the like. Specific examples thereof include, for example, Pictrico manufactured by Asahi Glass Co., Ltd .; professional photo paper manufactured by Canon Inc., super photo paper, matte photo paper, glossy gold, platinum grade; photographic paper manufactured by Seiko Epson Corporation ( Glossy), photo matte paper, photo paper Crispier (high gloss); Premium Plus Photo Paper, Premium Glossy Film, manufactured by Hewlett-Packard Japan; Advanced Paper, Premium Glossy Film, Photo Paper, manufactured by Hewlett-Packard Company; Advanced photo paper; Photo-like QP manufactured by Konica Corporation; Painting photo finish Pro manufactured by Fuji Film Co., Ltd .; and the like.
On the other hand, examples of the information transmission sheet that is not particularly provided with an ink receiving layer include plain paper, high-quality paper, and coated paper. Many types of plain paper are commercially available depending on the application. Examples of commercially available plain paper include: Double-sided plain plain paper manufactured by Seiko Epson Corporation; PB PAPER GF-500 manufactured by Canon Inc .; Multipurpose Paper, All-in-One Printing Paper manufactured by Hewlett-Packard Company. Inkjet mat paper manufactured by Mitsubishi Paper Industries Co., Ltd., trade name DL-9084; Premium multi-purpose paper 4024 manufactured by Xerox Co., Ltd .; NPi Form <70> manufactured by Nippon Paper Industries Co., Ltd. In addition, PPC (plain paper copy) paper and the like are plain paper.

The ink composition is very clear on the recording material, has high saturation and printing density, and gives a black recorded image with an ideal hue. Further, the aqueous black ink composition of the present invention has very good storage stability without solid precipitation, physical property change, hue change and the like after long-term storage.
The aqueous black ink composition of the present invention is used for inkjet recording and writing instruments, and even when used as an inkjet ink, solid precipitation due to drying of the ink composition near the nozzle is very unlikely to occur. ) Is not blocked. In addition, the aqueous black ink composition of the present invention uses a continuous ink jet printer, and when the ink is recirculated at a relatively long time interval or used intermittently by an on-demand ink jet printer, Does not cause changes in physical properties.
Furthermore, the image recorded with the water-based black ink composition of the present invention has various fastness properties such as water resistance, moisture resistance, ozone gas resistance, abrasion resistance, and light resistance, particularly light resistance and water resistance.
In addition, the recording material is excellent in long-term storage stability, and is particularly excellent in water resistance even on an inkjet-dedicated paper together with a hue on plain paper.

EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples. Moreover, in each structural formula of the compound obtained in the Example, acidic functional groups, such as a sulfo group, were described in the form of a free acid.
[(A) Preparation of Ink Composition]
[Examples 1 to 4 and Comparative Example 1]
Each component described in Table 5 below was mixed and stirred for about 1 hour to make a solution, and then filtered through a 0.45 μm membrane filter (trade name cellulose acetate filter paper manufactured by Advantech) for evaluation test. Ink compositions were prepared. The numerical value of each component in the following Table 5 means “part”.
In addition, the pigment | dye represented by Formula (22) is to patent document 3, the pigment | dye represented by Formula (4) is to patent document 6, and the mixture of the pigment | dye represented by Formula (3) is to patent document 7. Were synthesized according to the respective methods described. Among these, the pigment | dye represented by Formula (3) was used with the mixture as it was.

Abbreviations in Table 5 below have the following meanings.
Formula (22): The pigment | dye represented by the said Formula (22).
Formula (4): The pigment | dye represented by the said Formula (4).
Formula (3): The pigment | dye represented by the said Formula (3).
DY86: C.I. I. Direct yellow 86.
DY132: C.I. I. Direct yellow 132.
GLY: Glycerin.
2-PY: 2-pyrrolidone.
IPA: isopropyl alcohol.
BCA: Butyl carbitol.
SF440: Surfynol 440.
TEA: triethanolamine.

[(B) Inkjet recording]
The ink compositions prepared in each Example and Comparative Example were subjected to inkjet recording on the following plain paper and inkjet exclusive paper using an inkjet printer manufactured by EPSON Co., Ltd., trade name PX205.
Plain paper: NPi Form <70> manufactured by Nippon Paper Industries Co., Ltd.
Inkjet dedicated paper: Advanced Paper, manufactured by Hewlett-Packard Company.
During ink jet recording, an image pattern is created so that six levels of gradations of 100%, 80%, 60%, 40%, 20%, and 10% density can be obtained, and a dark black to light black gradation recorded matter. Got. The following evaluation tests were carried out using this as a test piece.

[(C) Colorimeter and colorimetric conditions]
When color measurement was necessary in the following evaluation tests, color measurement was performed using the following colorimeter and color measurement conditions.
Colorimeter:
Product name SpectroEye manufactured by GRETAG-MACBETH.
Colorimetric conditions:
The density standard is ANSI A, the viewing angle is 2 °, and the light source is D50.

[(D) Water resistance test]
Among the test pieces of Examples and Comparative Examples obtained in the above “(B) Inkjet recording”, after preparing a test piece of ink jet dedicated paper, it was naturally dried for 24 hours. After the dried test piece was immersed in ion-exchanged water for 1 minute, the test piece was slowly taken out from the water and dried by natural drying for 24 hours. The test piece was measured for color difference (ΔE) before and after the test. The smaller the obtained color difference ΔE means that there is less discoloration of the hue due to water, and the water resistance is excellent.
AA: ΔE is less than 3.0.
A: ΔE is 3.0 or more and less than 4.0.
B: ΔE is 4.0 or more and less than 5.0.
C: ΔE is 5.0 or more.
The results are shown in Table 6 below.

  As is apparent from the results in Table 6, Example 1 containing the dye corresponding to Formula (2) and Formula (2) compared to Comparative Example 1 containing only the dye corresponding to Formula (1) above. It was confirmed that Examples 2 to 4 containing yellow or orange pigments in addition to the above were excellent in water resistance.

[(E) Hue evaluation test]
Among the test pieces of each Example and Comparative Example obtained in the above “(B) Inkjet recording”, L *, a *, b * of the gradation portion of 100% density in the test piece using plain paper 1 The chroma C * value was calculated by the following formula.
C * = (a * ² + b * ² ) ^1/2
In addition, obtained C * is a preferable black hue, so that it is close to 0, and it evaluated it on the basis of the following four steps. In this standard, “B” or more is a normal practical black hue.
A: C * is less than 3.0.
B: C * is 3.0 or more and less than 4.0.
C: C * is 4.0 or more and less than 7.0.
D: C * is 7.0 or more.
The results are shown in Table 7 below.

  As is clear from the results of Table 7, in addition to the dyes corresponding to the above formulas (1) and (2), each example containing a yellow or orange dye produces an achromatic and high-quality black image. Confirmed to give.

  Since the water-based ink composition of the present invention is excellent in water resistance and hue, it is very suitably used for various recording applications, particularly inkjet recording.

Claims (10)

An ink composition containing at least a dye represented by the following formula (1) or a salt thereof or a mixture thereof, and a dye represented by the following formula (2) or a salt thereof or a mixture thereof.

(In the above formula (1),
R ₁ , R ₂ , R ₅ , R ₆ and R ₇ each independently have a hydrogen atom, a halogen atom, a cyano group, a hydroxy group, a carboxy group, a sulfo group, a sulfamoyl group, a nitro group, or a substituent. Represents a group selected from the group consisting of an alkoxy group which may have a substituent, an alkylsulfonyl group which may have a substituent, an alkyl group, an arylsulfamoylamino group which may have a substituent, and an alkylcarbonylamino group .
R ₃ and R ₄ are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a cyano group, a sulfo group, a carboxy group, a nitro group, an optionally substituted alkoxy group, and an alkyl group. Represents a group.
n represents 0 or 1. )

(In the above formula (2),
X and Y each independently represent a group selected from the group consisting of a substituted or unsubstituted amino group, an alkoxy group, a hydroxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted aryloxy group,
B represents a carbonyl group or a sulfonyl group,
q represents an integer of 0 to 2,
R ₁₁ represents a substituted or unsubstituted phenyl group, an alkyl group, a phenacyl group, or a phenoxymethylcarbonyl group, and A represents a hydrogen atom or a substituent. )   The ink composition according to claim 1, further comprising at least one dye selected from a yellow dye and an orange dye.   The yellow dye is C.I. I. The ink composition according to claim 2, wherein the ink composition is a dye selected from Direct Yellow 86 and 132. The orange dye is C.I. I. The ink composition according to claim 2, which is a dye selected from Direct Orange 39 and a dye represented by the following formula (3), a salt thereof, or a mixture thereof.

(In said formula (3), Q represents the integer of 1-3.)   The ink composition according to any one of claims 1 to 4, further comprising at least one water-soluble organic solvent.   The ink composition according to any one of claims 1 to 5, which is used for inkjet recording.   An ink jet recording method for performing recording by ejecting the droplets of the ink composition according to any one of claims 1 to 6 in accordance with a recording signal and attaching the droplets to a recording material.   The ink jet recording method according to claim 7, wherein the recording material is an information transmission sheet.   The colored body colored with the ink composition as described in any one of Claims 1-6. An ink jet printer loaded with a container containing the ink composition according to claim 1.