JP2015117254A - Ink, ink cartridge, and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink that suppresses stains inside a recording device even when borderless recording is performed, and is excellent in intermittent discharge stability.SOLUTION: An ink for inkjet contains a first color material and a second color material. The first color material is represented by following general formula (I), and the second color material is represented by following general formula (II). The ink further contains a 18-crown-6 ether. The content (mass%) of the 18-crown-6 ether in the ink is not less than 1.00 times and not more than 2.00 times the content (mass%) of the second color material in the ink.

Description

  The present invention relates to an ink, an ink cartridge, and an ink jet recording method.

  The ink jet recording method is a recording method in which an ink droplet is applied to a recording medium such as plain paper to form an image, and is rapidly spreading due to its low price and an increase in recording speed. In general, the recorded matter obtained by the ink jet recording method has low image fastness as compared with a silver salt photograph. In particular, when the recorded material is exposed to environmental gases such as light, humidity, heat, or ozone gas present in the air for a long time, the color material of the recorded material deteriorates, and the color tone of the image or fading easily occurs. There is a problem.

  The discoloration of an image recorded using an ink having a black hue is often accompanied by a change in color tone due to deterioration of the color material. In order to solve such a problem, various proposals have been made for improving the ozone resistance of an image by using an ink containing a coloring material having a structure excellent in ozone resistance. For example, there is a proposal regarding an ink using a polyazo compound (see Patent Document 1).

  On the other hand, in the ink jet recording method, by applying ink to a region slightly larger than the size of the recording medium, an image is recorded over the entire surface of the recording medium, and no margin is generated at the edge of the recording medium (edgeless). Recording). When performing borderless recording, an ink absorbing member that absorbs ink ejected to the outside of the recording medium is provided with a predetermined amount so that the ink ejected to the outside of the recording medium does not contaminate the inside of the recording apparatus or the recording medium. There is known a method of arranging at a location (see Patent Documents 2 and 3). As the material of the ink absorbing member, urethane foam or the like is widely used.

  Further, in the case of using an ink that easily aggregates, a technique for impregnating the ink absorbing member with an organic solvent has been proposed in order to prevent the ink applied to the ink absorbing member from aggregating and depositing due to evaporation of moisture. (See Patent Document 4). Furthermore, it has been proposed to suppress the accumulation by adding the ink that is difficult to accumulate aggregates to the ink that easily accumulates aggregates and mixing the inks (see Patent Document 5).

JP 2008-169374 A JP 2001-260391 A JP 2002-337405 A JP 2004-174978 A JP 2011-051135 A

  The present inventors have examined the ink containing the black color material described in Patent Document 1. However, it has been found that the fastness of images recorded using this ink has not reached the level required in recent years. Therefore, as a result of further studies, when the black color material described in Patent Document 1 and the color material having a specific structure are used in combination, it has high fastness and can record an excellent black color tone. I found. In the present invention, the excellent black color tone means “neutral black color tone”. Specifically, this means that the image shows absorption close to flat in the visible light region (wavelength region of 400 nm to 780 nm), that is, the absorption spectrum does not have a large absorption peak.

  However, after adopting the methods described in Patent Documents 2 and 3 and performing borderless recording with ink using a color material having the above specific structure, the ink deposited on the ink absorbing member contacts the recording medium. A new problem has arisen in that dirt is generated by doing. In response to this problem, it has been found that the method described in Patent Document 4 can reduce the ink accumulation, but the ink accumulation may not be suppressed when the number of borderless recordings is increased. In addition, although the method described in Patent Document 5 can suppress the initial ink accumulation, it cannot suppress the ink accumulation when the number of borderless recordings increases. Furthermore, it was found that this ink has insufficient intermittent ejection stability.

  Accordingly, an object of the present invention is to provide an ink that suppresses contamination inside the recording apparatus and has excellent intermittent ejection stability even when borderless recording is performed. Another object of the present invention is to provide an ink cartridge and an ink jet recording method using the ink.

  The above object is achieved by the present invention described below. That is, the ink according to the present invention is an ink jet ink containing a first color material and a second color material, and the first color material is a compound represented by the following general formula (I). The second colorant is a compound represented by the following general formula (II) and further contains 18-crown-6-ether, and the ink contains 18-crown-6-ether The amount (mass%) is a mass ratio with respect to the content (mass%) of the second color material and is 1.00 times or more and 2.00 times or less.

In the general formula (I), R ₁ represents an alkyl group having 1 to 4 carbon atoms; an alkyl group having 1 to 4 carbon atoms substituted with a carboxy group; a phenyl group; a phenyl group substituted with a sulfonic acid group; or R ₂ represents a cyano group; a carbamoyl group; or a carboxy group, and R ₃ and R ₄ each independently represent a hydrogen atom; an alkyl group having 1 to 4 carbon atoms; a halogen atom; Represents an alkoxy group having 1 to 4; or a sulfonic acid group, and R ₅ and R ₇ are each independently selected from the group consisting of an alkylthio group having 1 to 4 carbon atoms; or a hydroxy group, a sulfonic acid group, and a carboxy group. represents at least one substituted alkylthio group having 1 to 4 carbon atoms in the group, R ₆ and R ₈ each independently represents an alkylcarbonylamino group having 1 to 4 carbon atoms, ₉ and R _10, each independently, a hydrogen atom; a carboxyl group; a sulfonic group; an acetylamino group; a halogen atom; an alkoxy group having 1 to 4 carbon atoms; an alkyl group having 1 to 4 carbon atoms or hydroxy groups, carbon Represents an alkoxy group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of an alkoxy group having 1 to 4 groups, a sulfonic acid group, and a carboxy group, and R ₁₁ , R _12, and R ₁₃ are: Each independently a hydrogen atom; a carboxy group; a sulfonic acid group; a hydroxy group; an acetylamino group; a halogen atom; a cyano group; a nitro group; a sulfamoyl group; an alkyl group having 1 to 4 carbon atoms; A group; at least one selected from the group consisting of a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, and a carboxy group An alkoxy group having 1 to 4 carbon atoms substituted with a group; an alkylsulfonyl group having 1 to 4 carbon atoms; or substituted with at least one group selected from the group consisting of a hydroxy group, a sulfonic acid group, and a carboxy group An alkylsulfonyl group having 1 to 4 carbon atoms is represented.

In the general formula (II), R ₁ represents a monovalent group, R ₂ represents —OR ₃ or —NHR ₄ (R ₃ and R ₄ represent a hydrogen atom or a monovalent group), R ₅ Represents an anionic group in which the counter ion is a potassium ion, R ₆ represents an arylene group or a divalent heterocyclic group, R ₇ represents a divalent linking group, and m represents 0 or 1.

  According to the present invention, it is possible to provide an ink excellent in intermittent ejection stability while suppressing contamination inside the recording apparatus even when borderless recording is performed. In addition, according to the present invention, it is possible to provide an ink cartridge and an ink jet recording method using this ink.

It is sectional drawing which shows typically one Embodiment of the ink cartridge of this invention. FIG. 2 is a diagram schematically illustrating an example of an ink jet recording apparatus used in the ink jet recording method of the present invention, in which (a) is a perspective view of a main part of the ink jet recording apparatus, and (b) is a perspective view of a head cartridge.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. In the present invention, when the compound is a salt, the salt is dissociated into ions in the ink, but is expressed as “contains a salt” for convenience. Ink jet ink may be simply referred to as “ink”.

  In order to obtain an ink having high fastness and capable of recording an image having an excellent black tone, the present inventors have obtained a compound represented by the general formula (I) (first coloring material) and a general formula The ink containing the compound represented by (II) (second color material) was examined. As a result, it was found that the image characteristics are satisfactory by using these color materials together.

  However, when borderless recording is performed using this ink, it has been found that a new problem arises that the ink deposited on the ink absorbing member is contaminated by coming into contact with the recording medium. The present inventors presume the cause of such a problem as follows.

  When borderless recording was performed using ink containing only the first color material as the color material, the first color material aggregated and deposited in the ink absorbing member to which the ink was applied. However, in this case, the degree of aggregation and deposition of the coloring material was not so severe as compared to the case where the borderless recording was performed using the ink containing the first coloring material and the second coloring material. On the other hand, when borderless recording was performed using ink containing only the second color material as the color material, the second color material did not aggregate and accumulate in the ink absorbing member to which the ink was applied. From these facts, it became clear that the second coloring material promotes the aggregation and deposition of the first coloring material.

  As a result of further studies by the present inventors, it has been found that the aggregation and deposition of the first coloring material are promoted by potassium ions which are counter ions of the anionic group of the second coloring material. From this, it was thought that the effect | action by a potassium ion should just be suppressed. As a result of examining the technique, potassium ions are included by adding 18-crown-6-ether that includes potassium ions to the ink, and aggregation and deposition of the first coloring material are suppressed. I found.

  It is also considered that aggregation and deposition of the first coloring material can be suppressed by making the counter ion of the anionic group of the second coloring material other than potassium ion. However, since the solubility of the second coloring material is impaired, the aggregation and deposition of the second coloring material in the ink absorbing member cannot be suppressed.

  On the other hand, it has also been found that when a large amount of 18-crown-6-ether is added to the ink, the intermittent ejection stability of the ink tends to be lowered. Here, the intermittent ejection stability will be described. When an image is recorded by the ink jet recording method, if the state where ink is not ejected from a certain ejection port of the recording head for a certain period of time continues, evaporation of water in the ink from the ejection port proceeds. Thereafter, when the next first drop of ink is ejected from the ejection port, the ejection of the ink becomes unstable or cannot be ejected. The reason why this phenomenon occurs is as follows. As the water in the ink evaporates from the ejection port, the viscosity of the ink existing in the vicinity of the ejection port increases rapidly. Then, the ejection port is easily blocked by the thickened ink, and as a result, the ink is not ejected normally and the intermittent ejection stability is lowered.

  Based on the above points, the present inventors have conducted a study to suppress stains inside the printing apparatus and ensure intermittent ejection stability of ink even when borderless printing is performed. Found that the following requirements must be met. That is, the content (mass%) of 18-crown-6-ether in the ink is represented by a mass ratio with respect to the content (mass%) of the compound (second coloring material) represented by the general formula (II). , 1.0 to 2.0 times.

<Ink>
Hereinafter, each component constituting the ink of the present invention will be described in detail.

(First color material)
The ink of the present invention contains a compound represented by the following general formula (I) as a first color material.

In the general formula (I), R ₁ represents an alkyl group having 1 to 4 carbon atoms; an alkyl group having 1 to 4 carbon atoms substituted with a carboxy group; a phenyl group; a phenyl group substituted with a sulfonic acid group; or Represents a carboxy group. R ₂ represents a cyano group; a carbamoyl group; or a carboxy group. R ₃ and R ₄ each independently represent a hydrogen atom; an alkyl group having 1 to 4 carbon atoms; a halogen atom; an alkoxy group having 1 to 4 carbon atoms; or a sulfonic acid group. R ₅ and R ₇ are each independently an alkylthio group having 1 to 4 carbon atoms; or 1 to 1 carbon atoms substituted with at least one group selected from the group consisting of a hydroxy group, a sulfonic acid group, and a carboxy group. 4 represents an alkylthio group. R ₆ and R ₈ each independently represents an alkylcarbonylamino group having 1 to 4 carbon atoms. R ₉ and R ₁₀ are each independently a hydrogen atom; a carboxy group; a sulfonic acid group; an acetylamino group; a halogen atom; an alkyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 4 carbon atoms; It represents an alkoxy group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, and a carboxy group. R ₁₁ , R ₁₂ and R ₁₃ are each independently a hydrogen atom; a carboxy group; a sulfonic acid group; a hydroxy group; an acetylamino group; a halogen atom; a cyano group; a nitro group; a sulfamoyl group; A group having 1 to 4 carbon atoms; a group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, and a carboxy group; An alkylsulfonyl group having 1 to 4 carbon atoms; or an alkylsulfonyl group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of a hydroxy group, a sulfonic acid group and a carboxy group; Represent.

The compound represented by the general formula (I) has tautomers. As tautomers, in addition to the compounds represented by the general formula (I), compounds represented by the following formulas (III) and (IV) can be considered. In the present invention, these compounds (tautomers) and salts are also included in the compound represented by the general formula (I). Incidentally, _{R 1} to _{R 13} in formula (III) and (IV) has the same meaning as _{R 1} to _{R 13} in the general formula (I).

In general formula (I), examples of the alkyl group having 1 to 4 carbon atoms represented by R ₁ include a linear or branched unsubstituted alkyl group. Among these, a linear unsubstituted alkyl group is preferable. Specific examples of the alkyl group having 1 to 4 carbon atoms include linear alkyl groups such as methyl, ethyl, n-propyl, and n-butyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, and tert-butyl. Can be mentioned. Among these, a methyl group and an n-propyl group are preferable, and a methyl group is more preferable.

In the general formula (I), the alkyl group having 1 to 4 carbon atoms substituted by the carboxy group represented by R ₁ is _{one in} which any of the above-mentioned unsubstituted alkyl groups is substituted with a carboxy group. Can be mentioned. The substitution position of the carboxy group is preferably the terminal of the alkyl group. Further, the number of substitutions of the carboxy group is preferably 1 or 2, and more preferably 1. Specific examples of the alkyl group having 1 to 4 carbon atoms substituted with a carboxy group include carboxymethyl and 2-carboxyethyl. Among these, a carboxymethyl group is preferable.

In the general formula (I), examples of the phenyl group substituted with the sulfonic acid group represented by R ₁ include a phenyl group substituted with 1 to 3, preferably 1 or 2 sulfonic acid groups. . Specific examples of the phenyl group substituted with a sulfonic acid group include 3-sulfophenyl, 4-sulfophenyl, 2,4-disulfophenyl, and 3,5-disulfophenyl. Among these, a 4-sulfophenyl group is preferable.

R ₁ in the general formula (I) is an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms substituted with a carboxy group, a phenyl group, or a phenyl group substituted with a sulfonic acid group. It is preferable. R ₁ is more preferably a phenyl group substituted with an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a sulfonic acid group, and more preferably an alkyl group having 1 to 4 carbon atoms or a phenyl group. preferable. R ₁ is particularly preferably an alkyl group having 1 to 4 carbon atoms, and most preferably a methyl group.

R ₂ in the general formula (I) is preferably a cyano group or a carbamoyl group, and more preferably a cyano group.

In general formula (I), examples of the alkyl group having 1 to 4 carbon atoms represented by R ₃ and R ₄ include those exemplified for the alkyl group having 1 to 4 carbon atoms represented by R ₁ , and preferred ones. The same thing can be mentioned including.

In general formula (I), examples of the halogen atom represented by R ₃ and R ₄ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and among these, a chlorine atom is preferable.

In the general formula (I), examples of the alkoxy group having 1 to 4 carbon atoms represented by R ₃ and R ₄ include linear or branched alkoxy groups. Among these, a linear alkoxy group is preferable. The alkoxy group may have a substituent, but an unsubstituted alkoxy group is preferable. Specific examples of the alkoxy group having 1 to 4 carbon atoms include straight-chain alkoxy groups such as methoxy, ethoxy, n-propoxy, and n-butoxy; branched-chain alkoxy groups such as isopropoxy, isobutoxy, sec-butoxy, and tert-butoxy And so on. Of these, a methoxy group is particularly preferable.

R ₃ and R _{4 in} general formula (I) are each independently preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a sulfonic acid group. A combination in which one of R ₃ and R ₄ is a hydrogen atom and the other is a sulfonic acid group is more preferable. In the case where one of R ₃ and R ₄ is a hydrogen atom and the other is a sulfonic acid group, the substitution position of the sulfonic acid group is two adjacent to any nitrogen atom constituting the benzimidazolopyrrolidone ring. Preferably they are either carbon atoms. The compound represented by the general formula (I) may be a mixture containing at least two kinds of positional isomers having different substitution positions of R ₃ and R ₄ from the viewpoint of ease of synthesis and cost.

Preferred combinations of R _{1 to} R _{4 in} the general formula (I) are as shown below. R ₁ : an alkyl group having 1 to 4 carbon atoms or a phenyl group (preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group)
R ₂ : cyano group or carbamoyl group (preferably cyano group)
R ₃ : hydrogen atom, methyl group, or methoxy group (preferably methoxy group)
R ₄ : Sulfonic acid group In general formula (I), examples of the alkylthio group having 1 to 4 carbon atoms represented by R ₅ and R ₇ include an unsubstituted alkylthio group in which alkyl is linear or branched. . Of these, a straight-chain unsubstituted alkylthio group is preferable. Specific examples of the alkylthio group having 1 to 4 carbon atoms include linear alkylthio groups such as methylthio, ethylthio, n-propylthio, and n-butylthio; branched alkylthio such as isopropylthio, isobutylthio, sec-butylthio, and tert-butylthio. Examples include groups.

In the general formula (I), the alkylthio group having 1 to 4 carbon atoms substituted by a specific substituent represented by R ₅ and R ₇ is any carbon constituting the alkylthio group having 1 to 4 carbon atoms. The thing which the specific substituent couple | bonded with the atom can be mentioned. The specific substituent is at least one group selected from the group consisting of a hydroxy group, a sulfonic acid group, and a carboxy group. The number of substituents is preferably 1 or 2, and more preferably 1. The position of the substituent is preferably a carbon atom other than the carbon atom to which the sulfur atom constituting the alkylthio group is bonded. Specific examples of the alkylthio group having 1 to 4 carbon atoms substituted with a specific substituent include hydroxyalkylthio groups such as 2-hydroxyethylthio, 2-hydroxypropylthio, and 3-hydroxypropylthio; 2-sulfoethylthio And sulfoalkylthio groups such as 3-sulfopropylthio; carboxyalkylthio groups such as 2-carboxyethylthio, 3-carboxypropylthio and 4-carboxybutylthio.

R ₅ and R _{7 in} formula (I) are each independently preferably a sulfoalkylthio group or a carboxyalkylthio group, more preferably a sulfoalkylthio group, and particularly preferably a sulfopropylthio group. preferable.

In the general formula (I), examples of the alkylcarbonylamino group having 1 to 4 carbon atoms represented by R ₆ and R ₈ include a linear or branched alkylcarbonylamino group having an alkyl group. Of these, a linear alkylcarbonylamino group is preferred. The alkylcarbonylamino group may have a substituent, but an unsubstituted alkylcarbonylamino group is preferable. Specific examples of the alkylcarbonylamino group having 1 to 4 carbon atoms include straight-chain unsubstituted groups such as acetylamino (methylcarbonylamino), propionylamino (ethylcarbonylamino), n-propylcarbonylamino, and n-butylcarbonylamino. An alkylcarbonylamino group; branched-chain unsubstituted alkylcarbonylamino groups such as isopropylcarbonylamino, isobutylcarbonylamino, sec-butylcarbonylamino, and pivaloylamino (tert-butylcarbonylamino). Among these, a linear unsubstituted alkylcarbonylamino group is preferable, and an acetylamino group is more preferable.

As a combination of R ₅ and R ₆ in general formula (I), it is preferable that R ₅ is a sulfoalkylthio group having 1 to 4 carbon atoms and R ₆ is an acetylamino group. More preferably, R ₅ is a sulfopropylthio group and R ₆ is an acetylamino group.

As a combination of R ₇ and R _{8 in} the general formula (I), it is preferable that R ₇ is a sulfoalkylthio group having 1 to 4 carbon atoms and R ₈ is an acetylamino group. More preferably, R ₇ is a sulfopropylthio group and R ₈ is an acetylamino group.

In the general formula (I), examples of the halogen atom represented by R ₉ and R ₁₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and among these, a chlorine atom is preferable.

In general formula (I), examples of the alkyl group having 1 to 4 carbon atoms represented by R ₉ and R ₁₀ include those exemplified for the alkyl group having 1 to 4 carbon atoms represented by R ₁ and preferred ones. The same thing can be mentioned including.

In the general formula (I), examples of the alkoxy group having 1 to 4 carbon atoms represented by R ₉ and R ₁₀ include those exemplified for the alkoxy group having 1 to 4 carbon atoms represented by R ₃ and R _4. The same thing can be mentioned including a preferable thing.

In general formula (I), the alkoxy group having 1 to 4 carbon atoms that is substituted with a specific substituent represented by R ₉ and R ₁₀ is any carbon constituting an alkoxy group having 1 to 4 carbon atoms. The thing which the specific substituent couple | bonded with the atom can be mentioned. The specific substituent is at least one group selected from the group consisting of a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, and a carboxy group. The number of substituents is preferably 1 or 2, and more preferably 1. The position of the substituent is preferably a carbon atom other than the carbon atom to which the oxygen atom constituting the alkoxy group is bonded. Specific examples of the alkoxy group having 1 to 4 carbon atoms substituted with a specific substituent include hydroxyalkoxy groups such as 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy; 2-sulfoethoxy, 3-sulfo Examples thereof include sulfoalkoxy groups such as propoxy and 4-sulfobutoxy; carboxyalkoxy groups such as 2-carboxyethoxy, 3-carboxypropoxy and 4-carboxybutoxy.

R ₉ is preferably a sulfoalkoxy group or a carboxyalkoxy group, more preferably a sulfoalkoxy group, and particularly preferably a sulfopropoxy group or a sulfobutoxy group. R ₁₀ is preferably an alkyl group, an alkoxy group, a sulfoalkoxy group, a carboxyalkoxy group, or an acetylamino group, more preferably an alkyl group, and particularly preferably a methyl group.

As a combination of R ₉ and R _{10 in} the general formula (I), it is preferable that R ₉ is a sulfoalkoxy group and R ₁₀ is an alkyl group. More preferably, R ₉ is a sulfopropoxy group (particularly 3-sulfopropoxy group) or a sulfobutoxy group (particularly 4-sulfobutoxy group), and R ₁₀ is a methyl group.

In the general formula (I), examples of the halogen atom represented by R ₁₁ , R ₁₂ and R ₁₃ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a chlorine atom is preferable.

In the general formula (I), as the alkyl group having 1 to 4 carbon atoms represented by R ₁₁ , R ₁₂ and R ₁₃ , those exemplified for the alkyl group having 1 to 4 carbon atoms represented by R ₁ The same thing can be mentioned including a preferable thing.

In the general formula (I), examples of the alkoxy group having 1 to 4 carbon atoms represented by R ₁₁ , R ₁₂ and R ₁₃ include the alkoxy groups having 1 to 4 carbon atoms represented by R ₃ and R _4. The same thing including what was preferable and what was preferable can be mentioned.

In the general formula (I), the alkoxy group having 1 to 4 carbon atoms substituted by a specific substituent represented by R ₁₁ , R ₁₂ and R ₁₃ is represented by R ₉ and R ₁₀ . The thing similar to what was illustrated about the C1-C4 alkoxy group substituted by the specific substituent can be mentioned. Further, preferred examples of the alkoxy group having 1 to 4 carbon atoms substituted with a specific substituent are the same as those exemplified in the above R ₉ and R ₁₀ . The specific substituent is at least one group selected from the group consisting of a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, and a carboxy group.

In the general formula (I), examples of the alkylsulfonyl group having 1 to 4 carbon atoms represented by R ₁₁ , R _12, and R ₁₃ include a linear or branched unsubstituted alkylsulfonyl group. Of these, a straight-chain unsubstituted alkylsulfonyl group is preferred. Specific examples of the alkylsulfonyl group having 1 to 4 carbon atoms include linear alkylsulfonyl groups such as methylsulfonyl, ethylsulfonyl, n-propylsulfonyl, and n-butylsulfonyl; branched alkyl such as isopropylsulfonyl and isobutylsulfonyl. A sulfonyl group can be mentioned. Among these, a methylsulfonyl group, an ethylsulfonyl group, or an isopropylsulfonyl group is preferable, and a methylsulfonyl group is more preferable.

In the general formula (I), the alkylsulfonyl group having 1 to 4 carbon atoms substituted with a specific substituent represented by R ₁₁ , R ₁₂ and R ₁₃ is the alkylsulfonyl group having 1 to 4 carbon atoms. In which a specific substituent is bonded to an arbitrary carbon atom that constitutes. The specific substituent is at least one group selected from the group consisting of a hydroxy group, a sulfonic acid group, and a carboxy group. The number of substituents is preferably 1 or 2, and more preferably 1. Specific examples of the alkylsulfonyl group having 1 to 4 carbon atoms substituted with a specific substituent include hydroxyethylsulfonyl, 2-hydroxypropylsulfonyl, 2-sulfoethylsulfonyl, 3-sulfopropylsulfonyl, and 2-carboxyethylsulfonyl. , 3-carboxypropylsulfonyl and the like.

R ₁₁ is preferably a hydrogen atom, a carboxy group, a sulfonic acid group, a chlorine atom, a nitro group, a methyl group, a methoxy group, or an alkylsulfonyl group having 1 to 4 carbon atoms. Further, it is more preferably a hydrogen atom; an electron-withdrawing group such as a carboxy group, a sulfonic acid group, a chlorine atom, a nitro group, an alkylsulfonyl group having 1 to 4 carbon atoms; a methyl group; or a methoxy group, and a hydrogen atom Or it is especially preferable that it is a chlorine atom.

R ₁₂ is a hydrogen atom, a carboxy group, a sulfonic acid group, a chlorine atom, a nitro group, a sulfamoyl group, a methyl group, a methoxy group, an alkylsulfonyl group having 1 to 4 carbon atoms, or a carboxyalkylsulfonyl group (the carbon number of alkyl is 1). To 4) and a sulfoalkylsulfonyl group having 1 to 4 carbon atoms (the alkyl has 1 to 4 carbon atoms). In addition, a hydrogen atom; an electron-withdrawing group such as a carboxy group, a sulfonic acid group, a chlorine atom, a nitro group, a sulfamoyl group, an alkylsulfonyl group having 1 to 4 carbon atoms, or a carboxyalkylsulfonyl group (the alkyl has 1 to 4), a sulfoalkylsulfonyl group having 1 to 4 carbon atoms (the alkyl has 1 to 4 carbon atoms); a methyl group; or a methoxy group, more preferably a sulfonic acid group, a nitro group, a sulfamoyl group, a methyl group, A methoxy group, a sulfopropylsulfonyl group, or a carboxyethylsulfonyl group is particularly preferable, and a sulfonic acid group is most preferable.

R ₁₃ is preferably a hydrogen atom, a carboxy group, a sulfonic acid group, a methoxy group, a chlorine atom, a nitro group, or an alkylsulfonyl group having 1 to 4 carbon atoms. Further, a hydrogen atom; an electron-withdrawing group such as a carboxy group, a sulfonic acid group, a chlorine atom, a nitro group, an alkylsulfonyl group having 1 to 4 carbon atoms; or a methoxy group is more preferable, and a hydrogen atom. Is particularly preferred.

Preferred combinations of R ₁₁ , R ₁₂ and R _{13 in} the general formula (I) are (a), (b) and (c) shown below. Among these, the combination (c) is particularly preferable.

(A) R ₁₁ is a hydrogen atom, R ₁₂ is a sulfonic acid group, R ₁₃ is a combination of hydrogen atoms (b) R ₁₁ is a hydrogen atom, R ₁₂ is a sulfamoyl group, and R ₁₃ is a combination of hydrogen atoms (c) R ₁₁ Is a hydrogen atom, R ₁₂ is a chlorine atom, and R ₁₃ is a combination of sulfonic acid groups Among the compounds represented by the general formula (I), the compounds represented by the following general formula (V) are preferred.

_{R 1} to _{R 13} in the general formula (V), the general formula (I) in the same meanings as those of _{R 1} to _{R 13} of the same as if preferred groups and combinations thereof also general formula (I). In the benzene ring substituted by R ₁₁ , R ₁₂ and R ₁₃ in the general formula (V), when the substitution position of the azo group is 1-position, the substitution position of R ₁₁ is 2-position or 3-position, R It is preferable that the substitution position of ₁₂ is 4-position and the substitution position of R ₁₃ is 5-position or 6-position. Preferred combinations of R _{1 to} R _{13 in} the general formula (I) are (i) and (ii) shown below. The combination (ii) is more preferable than the combination (i).

(I)
R ₁ : methyl group R ₂ : cyano group or carbamoyl group R ₃ : hydrogen atom, methyl group, or methoxy group R ₄ : sulfonic acid group R ₅ : C 1 to C 4 sulfoalkylthio group R ₆ : carbon number 1 to 4 alkylcarbonylamino group R ₇ : sulfoalkylthio group having 1 to 4 carbon atoms R ₈ : alkylcarbonylamino group (the alkyl has 1 to 4 carbon atoms)
R ₉ : a sulfoalkoxy group having 1 to 4 carbon atoms R ₁₀ : an alkyl group having 1 to 4 carbon atoms or an acetylamino group R ₁₁ , R ₁₂ and R ₁₃ : each independently a hydrogen atom, a sulfonic acid group, a methyl group, A methoxy group, a chlorine atom, a nitro group, or a sulfamoyl group (ii)
R ₁ : methyl group R ₂ : cyano group R ₃ : hydrogen atom or methoxy group R ₄ : sulfonic acid group R ₅ : sulfoalkylthio group having 1 to 4 carbon atoms R ₆ : acetylamino group R ₇ : 1 to 4 carbon atoms Sulfoalkylthio group R ₈ : acetylamino group R ₉ : sulfopropoxy group or sulfobutoxy group R ₁₀ : alkyl group having 1 to 4 carbon atoms R ₁₁ : hydrogen atom or sulfonic acid group R ₁₂ : sulfonic acid group or chlorine atom R ₁₃ : Hydrogen atom or sulfonic acid group As specific examples of the compound represented by the general formula (I), Exemplified compounds I-1 to I-90 shown in Table 1 and Table 2 may be mentioned. In addition, in Table 1 and Table 2, an exemplary compound is shown as a free acid type (H type) in the format of the following general formula (V '). Of course, the present invention is not limited to the exemplified compounds shown in Tables 1 and 2 as long as they are included in the structure of the general formula (I) and the definition thereof.

  In the present invention, among the exemplified compounds shown in Tables 1 and 2, Exemplified Compounds I-1 to I-12, I-19 and I-20 are preferable, and Exemplified Compounds I-7 to I-12, I-20 are preferred. −19 and I-20 are more preferable, and Exemplified Compounds I-7 to I-12 are particularly preferable. In particular, a compound represented by the following formula (III) is preferable.

(In the formula (III), R ₁ and R ₂ each independently represents SO ₃ M or OCH ₃ , and M independently represents lithium or sodium.)
(Second color material)
The 2nd color material combined with said compound represented by general formula (I) used as a 1st color material is a compound represented by the following general formula (II). In addition to the first color material and the second color material, the ink may further contain other color materials as long as the effects of the present invention are not impaired.

R ₁ in the general formula (II) represents a monovalent group. Monovalent groups include halogen atoms, alkyl groups, cycloalkyl groups, aralkyl groups, alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups, cyano groups, hydroxy groups, nitro groups, and carboxy groups (may be in salt form). , Alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group, alkylamino group, anilino group, acylamino group, aminocarbonylamino Group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkylsulfonylamino group, arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, Sulfonic acid group (may be salt type), alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, imide group, phosphino group, phosphinyl group, A phosphinyloxy group, a phosphinylamino group, and a silyl group can be mentioned.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  The alkyl group includes a substituted or unsubstituted alkyl group. As the substituted or unsubstituted alkyl group, an alkyl group having 1 to 30 carbon atoms is preferable. Examples of the substituent include the same as those mentioned as specific examples of the monovalent group described above. Among these, a hydroxy group, an alkoxy group, a cyano group, a halogen atom, a sulfonic acid group (may be a salt type), and a carboxy group (may be a salt type) are preferable. Examples of the alkyl group include methyl, ethyl, butyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, hydroxyethyl, cyanoethyl, 4-sulfobutyl, 4-carboxybutyl and the like.

  The cycloalkyl group includes a substituted or unsubstituted cycloalkyl group. As the substituted or unsubstituted cycloalkyl group, a cycloalkyl group having 5 to 30 carbon atoms is preferable. Examples of the cycloalkyl group include cyclohexyl, cyclopentyl, and 4-n-dodecylcyclohexyl.

  Aralkyl groups include substituted or unsubstituted aralkyl groups. As the substituted or unsubstituted aralkyl group, an aralkyl group having 7 to 30 carbon atoms is preferable. Examples of the aralkyl group include benzyl and 2-phenethyl.

  Alkenyl groups include linear, branched, or cyclic, substituted or unsubstituted alkenyl groups. As the substituted or unsubstituted alkenyl group, an alkenyl group having 2 to 30 carbon atoms is preferable. Examples of the alkenyl group include vinyl, allyl, prenyl, geranyl, oleyl, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl and the like.

  Alkynyl groups include substituted or unsubstituted alkynyl groups. As the substituted or unsubstituted alkynyl group, an alkynyl group having 2 to 30 carbon atoms is preferable. Examples of the alkynyl group include ethynyl and propargyl.

  The aryl group includes a substituted or unsubstituted aryl group. As the substituted or unsubstituted aryl group, an aryl group having 6 to 30 carbon atoms is preferable. Examples of the aryl group include phenyl, p-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl, and the like.

  The heterocyclic group includes a monovalent group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic or non-aromatic heterocyclic compound. As the substituted or unsubstituted heterocyclic group, a 5-membered or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms is preferable. Examples of such aromatic heterocyclic groups include 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl and the like.

  The alkoxy group includes a substituted or unsubstituted alkoxy group. As the substituted or unsubstituted alkoxy group, an alkoxy group having 1 to 30 carbon atoms is preferable. Examples of the alkoxy group include methoxy, ethoxy, isopropoxy, n-octyloxy, methoxyethoxy, hydroxyethoxy, 3-carboxypropoxy and the like.

  The aryloxy group includes a substituted or unsubstituted aryloxy group. The substituted or unsubstituted aryloxy group is preferably an aryloxy group having 6 to 30 carbon atoms. Examples of the aryloxy group include phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylaminophenoxy and the like.

  As the silyloxy group, a silyloxy group having 3 to 20 carbon atoms is preferable. Examples of the silyloxy group include trimethylsilyloxy and t-butyldimethylsilyloxy.

  The heterocyclic oxy group includes a substituted or unsubstituted heterocyclic oxy group. As the substituted or unsubstituted heterocyclic oxy group, a heterocyclic oxy group having 2 to 30 carbon atoms is preferable. Examples of the heterocyclic oxy group include 1-phenyltetrazole-5-oxy, 2-tetrahydropyranyloxy and the like.

  As the acyloxy group, a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, and a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms are preferable. Examples of the acyloxy group include formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy and the like.

  The carbamoyloxy group includes a substituted or unsubstituted carbamoyloxy group. As the substituted or unsubstituted carbamoyloxy group, a carbamoyloxy group having 1 to 30 carbon atoms is preferable. Examples of the carbamoyloxy group include N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy, N, N-di-n-octylaminocarbonyloxy, Nn-octylcarbamoyloxy and the like. Can do.

  The alkoxycarbonyloxy group includes a substituted or unsubstituted alkoxycarbonyloxy group. The substituted or unsubstituted alkoxycarbonyloxy group is preferably an alkoxycarbonyloxy group having 2 to 30 carbon atoms. Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy, ethoxycarbonyloxy, t-butoxycarbonyloxy, n-octylcarbonyloxy and the like.

  The aryloxycarbonyloxy group includes a substituted or unsubstituted aryloxycarbonyloxy group. The substituted or unsubstituted aryloxycarbonyloxy group is preferably an aryloxycarbonyloxy group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyloxy group include phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, p- (n-hexadecyloxy) phenoxycarbonyloxy and the like.

  The alkylamino group includes a substituted or unsubstituted alkylamino group. As the substituted or unsubstituted alkylamino group, an alkylamino group having 1 to 30 carbon atoms is preferable. Examples of the alkylamino group include methylamino and dimethylamino.

  The anilino group includes a substituted or unsubstituted anilino group. As the substituted or unsubstituted anilino group, an anilino group having 6 to 30 carbon atoms is preferable. Examples of the anilino group include anilino, N-methylanilino, diphenylamino and the like.

  The acylamino group is preferably a formylamino group, a substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms. Examples of the acylamino group include formylamino, acetylamino, pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino and the like.

  The aminocarbonylamino group includes a substituted or unsubstituted aminocarbonylamino group. As the substituted or unsubstituted aminocarbonylamino group, an aminocarbonylamino group having 1 to 30 carbon atoms is preferable. Examples of the aminocarbonylamino group include carbamoylamino, N, N-dimethylaminocarbonylamino, N, N-diethylaminocarbonylamino, morpholinocarbonylamino and the like.

  The alkoxycarbonylamino group includes a substituted or unsubstituted alkoxycarbonylamino group. As the substituted or unsubstituted alkoxycarbonylamino group, an alkoxycarbonylamino group having 2 to 30 carbon atoms is preferable. Examples of the alkoxycarbonylamino group include methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methyl-methoxycarbonylamino and the like.

  The aryloxycarbonylamino group includes a substituted or unsubstituted aryloxycarbonylamino group. As the substituted or unsubstituted aryloxycarbonylamino group, an aryloxycarbonylamino group having 7 to 30 carbon atoms is preferable. Examples of the aryloxycarbonylamino group include phenoxycarbonylamino, p-chlorophenoxycarbonylamino, m- (n-octyloxy) phenoxycarbonylamino and the like.

  The sulfamoylamino group includes a substituted or unsubstituted sulfamoylamino group. As the substituted or unsubstituted sulfamoylamino group, a sulfamoylamino group having 0 to 30 carbon atoms is preferable. Examples of the sulfamoylamino group include sulfamoylamino, N, N-dimethylaminosulfonylamino, N, N-octylaminosulfonylamino and the like.

  The alkylsulfonylamino group includes a substituted or unsubstituted alkylsulfonylamino group. As the substituted or unsubstituted alkylsulfonylamino group, an alkylsulfonylamino group having 1 to 30 carbon atoms is preferable. Examples of the alkylsulfonylamino group include methylsulfonylamino and butylsulfonylamino.

  The arylsulfonylamino group includes a substituted or unsubstituted arylsulfonylamino group having 6 to 30 carbon atoms. As the substituted or unsubstituted arylsulfonylamino group, an arylsulfonylamino group having 6 to 30 carbon atoms is preferable. Examples of the arylsulfonylamino group include phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino and the like.

  The alkylthio group includes a substituted or unsubstituted alkylthio group. As the substituted or unsubstituted alkylthio group, an alkylthio group having 1 to 30 carbon atoms is preferable. Examples of the alkylthio group include methylthio, ethylthio, n-hexadecylthio and the like.

  The arylthio group includes a substituted or unsubstituted arylthio group. As the substituted or unsubstituted arylthio group, an arylthio group having 6 to 30 carbon atoms is preferable. Examples of the arylthio group include phenylthio, p-chlorophenylthio, m-methoxyphenylthio and the like.

  The heterocyclic thio group includes a substituted or unsubstituted heterocyclic thio group. As the substituted or unsubstituted heterocyclic thio group, a heterocyclic thio group having 2 to 30 carbon atoms is preferable. Examples of the heterocyclic thio group include 2-benzothiazolylthio, 1-phenyltetrazol-5-ylthio and the like.

  The sulfamoyl group includes a substituted or unsubstituted sulfamoyl group. As the substituted or unsubstituted sulfamoyl group, a sulfamoyl group having 0 to 30 carbon atoms is preferable. The sulfamoyl group includes N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoylsulfamoyl, N- (N '-Phenylcarbamoyl) sulfamoyl) and the like.

  The alkylsulfinyl group includes a substituted or unsubstituted alkylsulfinyl group. As the substituted or unsubstituted alkylsulfinyl group, an alkylsulfinyl group having 1 to 30 carbon atoms is preferable. Examples of the alkylsulfinyl group include methylsulfinyl and ethylsulfinyl.

  The arylsulfinyl group includes a substituted or unsubstituted arylsulfinyl group. The substituted or unsubstituted arylsulfinyl group is preferably an arylsulfinyl group having 6 to 30 carbon atoms. Examples of the arylsulfinyl group include phenylsulfinyl and p-methylphenylsulfinyl.

  The alkylsulfonyl group includes a substituted or unsubstituted alkylsulfonyl group. As the substituted or unsubstituted alkylsulfonyl group, an alkylsulfonyl group having 1 to 30 carbon atoms is preferable. Examples of the alkylsulfonyl group include methylsulfonyl and ethylsulfonyl.

  The arylsulfonyl group includes a substituted or unsubstituted arylsulfonyl group. As the substituted or unsubstituted arylsulfonyl group, an arylsulfonyl group having 6 to 30 carbon atoms is preferable. Examples of the arylsulfonyl group include phenylsulfonyl and p-methylphenylsulfonyl.

  As the acyl group, a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, a substituted or unsubstituted group having 4 to 30 carbon atoms, A heterocyclic carbonyl group bonded to a carbonyl group at a carbon atom is preferred. Examples of the acyl group include acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, p- (n-octyloxy) phenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl and the like.

  The aryloxycarbonyl group includes a substituted or unsubstituted aryloxycarbonyl group. The substituted or unsubstituted aryloxycarbonyl group is preferably an aryloxycarbonyl group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyl group include phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, p- (t-butyl) phenoxycarbonyl, and the like.

  The alkoxycarbonyl group includes a substituted or unsubstituted alkoxycarbonyl group. The substituted or unsubstituted alkoxycarbonyl group is preferably an alkoxycarbonyl group having 2 to 30 carbon atoms. Examples of the alkoxycarbonyl group include methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl and the like.

  The carbamoyl group includes a substituted or unsubstituted carbamoyl group. As the substituted or unsubstituted carbamoyl group, a carbamoyl group having 1 to 30 carbon atoms is preferable. Examples of the carbamoyl group include carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl and the like.

  The imide group includes a substituted or unsubstituted imide group. As the substituted or unsubstituted imide group, an imide group having 4 to 30 carbon atoms is preferable. Examples of the imide group include succinimide, phthalimide, glutarimide, hexaneimide and the like.

  The phosphino group includes a substituted or unsubstituted phosphino group. As the substituted or unsubstituted phosphino group, a phosphino group having 2 to 30 carbon atoms is preferable. Examples of the phosphino group include dimethylphosphino, diphenylphosphino, methylphenoxyphosphino and the like.

  The phosphinyl group includes a substituted or unsubstituted phosphinyl group. As the substituted or unsubstituted phosphinyl group, a phosphinyl group having 2 to 30 carbon atoms is preferable. Examples of the phosphinyl group include phosphinyl, dioctyloxyphosphinyl, diethoxyphosphinyl and the like.

  The phosphinyloxy group includes a substituted or unsubstituted phosphinyloxy group. As the substituted or unsubstituted phosphinyloxy group, a phosphinyloxy group having 2 to 30 carbon atoms is preferable. Examples of the phosphinyloxy group include diphenoxyphosphinyloxy and dioctyloxyphosphinyloxy.

  The phosphinylamino group includes a substituted or unsubstituted phosphinylamino group. As the substituted or unsubstituted phosphinylamino group, a phosphinylamino group having 2 to 30 carbon atoms is preferable. Examples of the phosphinylamino group include dimethoxyphosphinylamino and dimethylaminophosphinylamino.

  The silyl group includes a substituted or unsubstituted silyl group. The substituted or unsubstituted silyl group is preferably a silyl group having 3 to 30 carbon atoms. Examples of the silyl group include trimethylsilyl, t-butyldimethylsilyl, phenyldimethylsilyl and the like.

  Of the monovalent groups described above, those having a hydrogen atom may be substituted with the above-mentioned monovalent group. Examples of such a substituent include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Specific examples thereof include methylsulfonylaminocarbonyl, p-methylphenylsulfonylaminocarbonyl, acetylaminosulfonyl, and benzoylaminosulfonyl groups.

R ₂ in the general formula (II) represents —OR ₃ or —NHR ₄ . R ₃ and R ₄ represent a hydrogen atom or a monovalent group. Examples of the monovalent group include those exemplified for the monovalent group represented by R ₁ described above, and the same groups including preferred ones. R ₂ is preferably —OH or —NH ₂ , and more preferably —NH ₂ .

R ₅ in the general formula (II) represents an anionic group. This anionic group requires that the counter ion be a potassium ion. Examples of the anionic group include a carboxy group, a sulfonic acid group, a phosphoric acid group, and a phosphonic acid group. Of these, a carboxy group is preferable.

In addition, when the compound represented by the general formula (II) has a monovalent group or an ionic group as a substituent, a counter ion in the case of forming a salt includes alkali metal; ammonia (NH ₃ ); organic Mention may be made of cations such as ammonium. Examples of the alkali metal include lithium, sodium, and potassium. Examples of organic ammonium include alkylamines having 1 to 3 carbon atoms such as methylamine and ethylamine; 1 to 4 carbon atoms such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine. The following organic ammonium such as mono-, di- or trialkanolamines can be mentioned.

R ₆ in the general formula (II) represents an arylene group or a divalent heterocyclic group. The arylene group represented by R ₆ includes a substituted or unsubstituted arylene group. As the substituted or unsubstituted arylene group, an arylene group having 6 to 30 carbon atoms is preferable. Examples of the substituent include those similar to those exemplified for the monovalent group represented by the aforementioned R _1. Examples of the arylene group include phenylene and naphthylene.

The divalent heterocyclic group represented by R ₆ is preferably a 5-membered ring or a 6-membered ring. These divalent hetero rings may be further condensed, and may be an aromatic hetero ring or a non-aromatic hetero ring. In general, heterocyclic groups can be classified into type I and type II. Type I heterocyclic groups are known as acidic nuclei. Examples of type I heterocyclic groups include 5-pyrazolone ring, 5-aminopyrazole ring, oxazolone ring, barbituric acid ring, pyridone ring, rhodanine ring, pyrazolidinedione ring, pyrazolopyridone ring, Meldrum acid ring Can do. Of these, a 5-pyrazolone ring and a 5-aminopyrazole ring are preferable. Type II heterocyclic groups are known as basic nuclei. Type II heterocyclic groups include pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, cinnoline, phthalazine, quinoxaline, pyrrole, indole, furan, benzofuran, thiophene, benzothiophene, pyrazole, imidazole, benzimidazole , Triazole, oxazole, benzoxazole, thiazole, benzothiazole, isothiazole, benzisothiazole, thiadiazole, isoxazole, benzisoxazole, pyrrolidine, piperidine, piperazine, imidazolidine, thiazoline and the like. Among them, an aromatic heterocyclic group is preferable, and pyridine, pyrazine, pyrimidine, pyridazine, triazine, pyrazole, imidazole, benzimidazole, triazole, thiazole, benzothiazole, isothiazole, benzisothiazole, thiadiazole are more preferable, and light resistance is improved. From the viewpoint, thiadiazole is particularly preferable. The divalent heterocyclic group may have a substituent. Examples of the substituent include those similar to those exemplified for the monovalent group represented by the aforementioned R _1.

R ₇ in the general formula (II) represents a divalent linking group, and m represents 0 or 1. When m is 0, it means that two R ₆ are bonded to each other.

Examples of the divalent linking group represented by R ₇ include alkylene groups such as methylene, ethylene, propylene, butylene, and pentylene; alkenylene groups such as ethenylene and propenylene; alkynylene groups such as ethynylene and propynylene; phenylene, naphthylene, and the like A divalent heterocyclic group such as 6-chloro-1,3,5-triazine-2,4-diyl group, pyrimidine-2,4-diyl group, quinoxaline-2,3-diyl group; _{O -; - CO -; -} NR 9 - (R 9 is a hydrogen atom, an alkyl group or an aryl _{group); - S -; - SO} 2 -; - SO-; and thereof, and the like combinations.

The alkylene group, alkenylene group, alkynylene group, arylene group, divalent heterocyclic group, alkyl group represented by R ₉ , and aryl group may all have a substituent. Examples of the substituent include the same as those exemplified for the monovalent group represented by R ₁ described above. Examples of the alkyl group and aryl group represented by R ₉ include those exemplified above for the alkyl group and aryl group among the monovalent groups represented by R ₁ , including the preferred ones. be able to.

R ₇ in the general formula (II) is an alkylene group having 10 or less carbon atoms, an alkenylene group having 10 or less carbon atoms, an alkynylene group having 10 or less carbon atoms, an arylene group having 6 to 10 carbon atoms, or a divalent heterocyclic ring. More preferably, it is a group, —O—, —S—, or a combination thereof. Among these, a combination of —S— and an alkylene group is particularly preferable from the viewpoint of the stability of the compound represented by the general formula (II).

The total number of carbon atoms of the divalent linking group represented by R ₇ is preferably 0 to 50, more preferably 0 to 30, and particularly preferably 0 to 10.

In the present invention, it is particularly preferable that the compound represented by the general formula (II) has the following structure. R ₂ is preferably an amino group. R ₆ is preferably a heterocyclic group, more preferably thiadiazole. R ₇ is preferably an alkylene group or an alkylene group containing a hetero atom, and more preferably an alkylene group containing a hetero atom.

  When the suitable example of a compound represented by general formula (II) is represented by a free acid form, the example compounds II-1 to II-29 shown below can be mentioned. Of course, the present invention is not limited to the exemplified compounds shown below as long as it is included in the structure of the general formula (II) and its definition.

  In the present invention, among the exemplary compounds shown above, exemplary compounds II-1 to II-13, II-18 to II-22, and II-29 are preferable, and exemplary compound II-2 is more preferable. In particular, a compound represented by the following formula (IV) is preferable.

(Coloring material content)
The content (% by mass) of the first coloring material in the ink is preferably 0.2% by mass or more and 6.0% by mass or less based on the total mass of the ink. The content (% by mass) of the second coloring material in the ink is preferably 0.05% by mass or more and 2.0% by mass or less based on the total mass of the ink. The total content (% by mass) of the first color material and the second color material in the ink is preferably 0.3% by mass or more and 8.0% by mass or less based on the total mass of the ink. . Further, the content (% by mass) of the second color material is a mass ratio with respect to the content (% by mass) of the first color material, and is preferably 0.1 to 0.5 times. If the mass ratio is out of the range, an excellent black color tone may not be obtained.

(18-crown-6-ether)
The ink of the present invention contains 18-crown ether-6. Crown ether is a macrocyclic ether represented by (—CH ₂ —CH ₂ —O—) _n and is represented as X-crown ether-Y. X represents the total number of atoms constituting the ring, and Y represents the number of oxygen atoms. Since the crown ether has an unshared electron pair of oxygen atoms inside the ring, it takes in ions having a radius corresponding to the cavity radius of the ring. For example, 12-crown ether-4 optimally takes in lithium ions, 15-crown ether-5 takes in sodium ions, and 18-crown ether-6 takes in potassium ions.

  In the present invention, 18-crown ether-6 is used to take in potassium ions which are counter ions of the second color material. Further, by using the second color material and 18-crown ether-6 at a specific mass ratio, the inside of the recording apparatus can be prevented from being stained even when borderless recording is performed, and intermittent ejection stability can be achieved. Can be improved. Specifically, the content (mass%) of 18-crown-6-ether is a mass ratio with respect to the content (mass%) of the second color material and is 1.00 times or more and 2.00 times or less. It takes a thing. That is, (18-crown-6-ether content / second color material content) = 1.00 times or more and 2.00 times or less is required. When the mass ratio is less than 1.0 times, it is not possible to suppress stains inside the printing apparatus when borderless printing is performed, and when it is more than 2.0 times, the intermittent ejection stability of the ink is increased. It becomes insufficient. The mass ratio is more preferably 1.25 times or more and 1.75 times or less.

  The content (% by mass) of 18-crown-6-ether in the ink is preferably 0.1% by mass or more and 2.0% by mass or less, and 0.3% by mass or more based on the total mass of the ink. More preferably, it is 1.0 mass% or less.

(Aqueous medium)
In the ink of the present invention, water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent can be used. It is preferable to use deionized water (ion exchange water) as the water. The content (% by mass) of water in the ink is preferably 10.0% by mass or more and 90.0% by mass or less based on the total mass of the ink.

  The water-soluble organic solvent is not particularly limited as long as it is water-soluble, and alcohol, polyhydric alcohol, polyglycol, glycol ether, nitrogen-containing polar solvent, sulfur-containing polar solvent and the like can be used. The content (% by mass) of the water-soluble organic solvent in the ink is 5.0% by mass or more and 90.0% by mass or less, and further 10.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. It is preferable that If the content of the water-soluble organic solvent is out of the above range, a high level of ink ejection stability may not be obtained sufficiently.

(Other additives)
In addition to the components described above, the ink of the present invention is a water-soluble organic substance that is solid at room temperature, such as polyhydric alcohols such as trimethylolpropane and trimethylolethane, and urea derivatives such as urea and ethyleneurea, if necessary. A compound may be contained. Furthermore, the ink of the present invention contains a surfactant, a pH adjuster, a rust inhibitor, an antiseptic, an antifungal agent, an antioxidant, an anti-reduction agent, an evaporation accelerator, a chelating agent, and a water-soluble agent as necessary. Various additives such as a functional resin may be contained.

(Other inks)
In order to form a full-color image or the like, the ink of the present invention can be used in combination with another ink having a hue different from the ink of the present invention. Examples of the other ink include at least one ink selected from the group consisting of black ink, cyan ink, magenta ink, yellow ink, red ink, green ink, and blue ink. Further, a so-called light ink having substantially the same hue as these inks can be used in combination. The coloring material used for other inks and light inks may be a known dye or a newly synthesized dye.

<Ink cartridge>
The ink cartridge of the present invention includes ink and an ink storage unit that stores the ink. And the ink accommodated in this ink accommodating part is the ink of this invention demonstrated above. FIG. 1 is a cross-sectional view schematically showing an embodiment of the ink cartridge of the present invention. As shown in FIG. 1, an ink supply port 12 for supplying ink to the recording head is provided on the bottom surface of the ink cartridge. The inside of the ink cartridge is an ink storage portion for storing ink. The ink storage portion is composed of an ink storage chamber 14 and an absorber storage chamber 16, which communicate with each other via a communication port 18. The absorber housing chamber 16 communicates with the ink supply port 12. The ink storage chamber 14 stores liquid ink 20, and the absorber storage chamber 16 stores absorbers 22 and 24 that hold the ink in an impregnated state. The ink storage unit may have a form in which the entire amount of ink stored is held by an absorber without having an ink storage chamber for storing liquid ink. Further, the ink storage portion may have a form that does not have an absorber and stores the entire amount of ink in a liquid state. Further, the ink cartridge may be configured to have an ink storage portion and a recording head.

<Inkjet recording method>
The ink jet recording method of the present invention is a method of recording an image on a recording medium by discharging the ink of the present invention described above from an ink jet recording head. Examples of the method for ejecting ink include a method for imparting mechanical energy to the ink and a method for imparting thermal energy to the ink. In the present invention, it is particularly preferable to employ a method in which thermal energy is applied to the ink and the ink is ejected. Other than using the ink of the present invention, the steps of the ink jet recording method may be known.

  2A and 2B are diagrams schematically showing an example of an ink jet recording apparatus used in the ink jet recording method of the present invention. FIG. 2A is a perspective view of a main part of the ink jet recording apparatus, and FIG. 2B is a perspective view of a head cartridge. It is. The ink jet recording apparatus is provided with a conveying means (not shown) for conveying the recording medium 32 and a carriage shaft 34. A head cartridge 36 can be mounted on the carriage shaft 34. The head cartridge 36 includes recording heads 38 and 40, and is configured such that an ink cartridge 42 is set. While the head cartridge 36 is conveyed along the carriage shaft 34 in the main scanning direction, ink (not shown) is ejected from the recording heads 38 and 40 toward the recording medium 32. Then, the recording medium 32 is conveyed in the sub-scanning direction by a conveying unit (not shown), whereby an image is recorded on the recording medium 32.

  On the platen (not shown), an ink absorbing member is provided that absorbs ink applied to the outside of the recording medium when borderless recording is performed. As the ink absorbing member, a material having ink absorbability such as urethane foam is used.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further in detail, this invention is not limited at all by the following Example, unless the summary is exceeded. In addition, what is described as “parts” and “%” with respect to the component amounts is based on mass unless otherwise specified.

<Preparation of coloring material>
(Synthesis of Compound A)
With reference to the description of WO 2012/081640, a sodium salt of a compound represented by the following formula (1) was synthesized as a free acid form. The compound represented by formula (1) includes (A) a compound in which a methoxy group is substituted with b and a sulfonic acid group is substituted with a, c or d, and (B) a methoxy group substituted with c and a sulfonic acid group It is a mixture comprising 2 to 6 types of compounds, including a compound substituted with a, b or d. The compound represented by the formula (24) obtained above and lithium chloride were added to water and stirred. 2-Propanol was further added, and the precipitated solid was separated by filtration to obtain a wet cake. The obtained wet cake and lithium chloride were added to water and stirred. 2-Propanol was further added, and the precipitated solid was separated by filtration to obtain a wet cake. After the obtained wet cake was added to water, 2-propanol was further added. The precipitated solid was separated by filtration to obtain a wet cake. After the obtained wet cake was added to water, 2-propanol was further added. The precipitated solid was separated by filtration and dried to obtain a compound A in which 80.0% of the anionic group was a lithium salt type and 20.0% was a sodium salt type.

(Synthesis of Compound B)
With reference to the description in JP-A-2004-083903, a compound represented by the following formula (2) is synthesized as a free acid form, and an aqueous potassium hydroxide solution is added to adjust the pH to 8.0, A potassium salt type compound B was obtained.

<Preparation of ink>
Each component (unit:%) shown in the upper part of Table 3 was mixed and sufficiently stirred, and then each ink was prepared by pressure filtration with a filter having a pore size of 0.20 μm. “Acetylenol E100” in Table 3 is a trade name of a nonionic surfactant (manufactured by Kawaken Fine Chemicals). In the lower part of Table 3, the content A (%) of 18-crown-6-ether, the content B (%) of the second coloring material, and the mass ratio (times) of A / B in the ink are shown. ) Values are shown respectively.

<Evaluation>
Each ink obtained above was filled in an ink cartridge and mounted on an ink jet recording apparatus (trade name “PIXUS iP8600”, manufactured by Canon Inc.) that discharges ink from the recording head by the action of thermal energy. In this embodiment, a solid image recorded by applying 22 ng of ink to a unit area of 1/600 inch × 1/600 inch is defined as “recording duty is 100%”. In the present invention, according to the evaluation criteria for the following items, C is a level that is not acceptable, and A and B are levels that are acceptable. The evaluation results are shown in Table 4.

(Deposition suppression)
Using the above inkjet recording apparatus, a solid image with a recording duty of 100% is recorded on a recording medium (trade name “Canon Photo Paper / Glossy Professional PR-201L; manufactured by Canon) for 1,000 sheets with borderless recording. After recording, the ink absorbing member of the recording apparatus was visually confirmed, and deposition suppression was evaluated according to the following evaluation criteria.

A: There was no accumulation on the ink absorbing member, and the ink had permeated into the ink absorbing member. B: There was no accumulation on the ink absorbing member, but ink was accumulated on the surface of the ink absorbing member. C: There was deposit on the ink absorbing member.

(Intermittent discharge stability)
An ink cartridge was mounted on the ink jet recording apparatus modified so that the ejection volume per ink drop was about 2 pL, and the following operation was performed in an environment of a temperature of 25 ° C. and a relative humidity of 50%. The ink jet recording apparatus was left without discharging for more than 5 hours while keeping the temperature of the ink existing in the vicinity of the discharge port of the recording head from rising, and then the ink was discharged. Thereafter, after the ink ejection is paused for 5 seconds, the ink is ejected again without performing the recovery operation of the recording head, and the vertical ruled lines are recorded on the recording medium (trade name “HR-101”, manufactured by Canon). A product was made. The vertical ruled lines of the obtained recorded matter were visually confirmed, and the intermittent discharge stability was evaluated according to the following evaluation criteria.

A: The ruled line was not disturbed. B: The ruled line was slightly disturbed. C: The ruled line was not ejected or disturbed and could not be recorded normally.

Claims (5)

An ink-jet ink containing a first color material and a second color material,
The first colorant is a compound represented by the following general formula (I), and the second colorant is a compound represented by the following general formula (II);
Furthermore, it contains 18-crown-6-ether, and the content (mass%) of the 18-crown-6-ether in the ink is a mass ratio with respect to the content (mass%) of the second color material. And an ink having a ratio of 1.00 times to 2.00 times.

(In the general formula (I), R ₁ represents an alkyl group having 1 to 4 carbon atoms; an alkyl group having 1 to 4 carbon atoms substituted with a carboxy group; a phenyl group; a phenyl group substituted with a sulfonic acid group; Or a carboxy group, R ₂ represents a cyano group; a carbamoyl group; or a carboxy group, and R ₃ and R ₄ each independently represent a hydrogen atom; an alkyl group having 1 to 4 carbon atoms; a halogen atom; Represents an alkoxy group having 1 to 4; or a sulfonic acid group, and R ₅ and R ₇ are each independently selected from the group consisting of an alkylthio group having 1 to 4 carbon atoms; or a hydroxy group, a sulfonic acid group, and a carboxy group. represents at least one substituted alkylthio group having 1 to 4 carbon atoms in the group that, R ₆ and R ₈ each independently represents an alkylcarbonylamino group having 1 to 4 carbon atoms R ₉ and R ₁₀ each independently represent a hydrogen atom; a carboxyl group; a sulfonic group; an acetylamino group; a halogen atom; or a hydroxy group; an alkoxy group having 1 to 4 carbon atoms; an alkyl group having 1 to 4 carbon atoms Represents an alkoxy group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, and a carboxy group, and R ₁₁ , R _12, and R ₁₃ Each independently represents a hydrogen atom; a carboxy group; a sulfonic acid group; a hydroxy group; an acetylamino group; a halogen atom; a cyano group; a nitro group; a sulfamoyl group; an alkyl group having 1 to 4 carbon atoms; An alkoxy group; at least one selected from the group consisting of a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, and a carboxy group An alkoxy group having 1 to 4 carbon atoms, an alkylsulfonyl group having 1 to 4 carbon atoms; or at least one group selected from the group consisting of a hydroxy group, a sulfonic acid group, and a carboxy group. Represents an alkylsulfonyl group having 1 to 4 carbon atoms.)

(In the general formula (II), R ₁ represents a monovalent group, R ₂ represents —OR ₃ or —NHR ₄ (R ₃ and R ₄ represent a hydrogen atom or a monovalent group), R ₅ represents an anionic group in which the counter ion is a potassium ion, R ₆ represents an arylene group or a divalent heterocyclic group, R ₇ represents a divalent linking group, and m represents 0 or 1.) The ink according to claim 1, wherein the coloring material represented by the general formula (I) is a compound represented by the following formula (III).

(In the formula (III), R ₁ and R ₂ each independently represents SO ₃ M or OCH ₃ , and M independently represents lithium or sodium.) The ink according to claim 1 or 2, wherein the color material represented by the general formula (II) is a compound represented by the following formula (IV).
An ink cartridge comprising ink and an ink containing portion for containing the ink,
The ink cartridge according to claim 1, wherein the ink is an ink according to claim 1. An inkjet recording method for recording an image on a recording medium by discharging ink from an inkjet recording head,
An ink jet recording method, wherein the ink is the ink according to any one of claims 1 to 3.