JP2017171841A - Azo compound, ink composition, recording method, and colored body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye excellent in fastness, particularly, ozone gas resistance when recorded in inkjet-exclusive paper; and an ink composition containing the dye, particularly, a black ink composition for inkjet recording.SOLUTION: There are provided an azo compound represented by formula (1) or a tautomer thereof, or a salt thereof. In formula (1), Rrepresents C1-4 alkyl group and the like; Rrepresents a cyano group; Rand Reach independently represents H, a sulfo group, and the like; Rand Reach independently represents C1-C4 alkylthio group substituted with one or more groups selected from a hydroxy group, a sulfo group, or a carboxyl group; Ris an alkoxyl group of C1-4 sulfo group; Rrepresents an alkylcarbonylamino group of C2-4 carboxy group and the like; Rrepresents C1-4 alkylcarbonylamino group; Rrepresents a methyl group; and Rto Reach independently represents H, a sulfo group, C1-4 alkyl group, and the like.SELECTED DRAWING: None

Description

  The present invention relates to a novel azo compound or a tautomer thereof, or a salt thereof, an ink composition containing them, and a colored product colored by them.

A recording method using an ink jet printer, that is, an ink jet recording method is one of representative methods among various color recording methods. The ink jet recording method performs recording by generating droplets of ink 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. Moreover, since it has the feature that it is easy to reduce the size and increase the speed, it has been spreading rapidly in recent years, and is expected to grow greatly in the future.
Conventionally, water-based inks in which water-soluble pigments are dissolved in an aqueous medium have been used as fountain pens, felt-tip pens, and inks for ink jet recording. In general, a water-soluble organic solvent is added to these water-based inks in order to prevent clogging of the ink at the pen tip or the ink discharge nozzle. These inks provide a recorded image with sufficient density, do not cause clogging of the pen tip and nozzles, have good drying properties on recording materials, have little bleeding, and have storage stability. It is required to be excellent. Further, the water-soluble dye used is required to have particularly high solubility in water and high solubility in the water-soluble organic solvent added to the ink. Further, the formed image is required to have image fastness such as water resistance, light resistance, gas resistance and moisture resistance.

  Among these, the gas resistance refers to the resistance to a phenomenon in which ozone gas having an oxidizing action existing in the air acts on the dye on the recording material or in the recording material to cause the recorded image to discolor. It is. In addition to ozone gas, examples of the oxidizing gas having this kind of action include NOx and SOx. However, among these oxidizing gases, ozone gas is regarded as a main causative substance that promotes the discoloration phenomenon of ink jet recorded images, and particularly, ozone gas resistance is regarded as important. An ink receiving layer is provided on the surface of the exclusive inkjet paper capable of obtaining photographic image quality in order to expedite ink drying and to reduce bleeding at high image quality. In many cases, the ink receiving layer is made of a material such as a porous white inorganic material. On such a recording paper, the discoloration due to ozone gas or the like is noticeable. Since this discoloration phenomenon due to the oxidizing gas is characteristic of an ink jet recording image, improvement of gas resistance, particularly ozone gas resistance, is one of the most important issues in ink jet recording.

  In addition, the bronzing phenomenon may be a problem. The bronzing phenomenon is a phenomenon in which the dye becomes flickering on the metal piece on the surface of the non-recording material due to the association of the dye or the poor absorption of the ink. When this phenomenon occurs, the gloss, print quality, and print density are all inferior. Especially when a metal phthalocyanine dye is used as a pigment, it often appears as a “red float phenomenon” in the portion printed at a high density, and the balance of the entire image becomes non-uniform and the quality is deteriorated. A pigment that does not cause a phenomenon is desired. In recent years, glossy paper is often used as a recording medium having a texture similar to a photographic tone. However, when the bronzing phenomenon occurs, the glossiness on the surface of the recorded material varies, and the texture of the image is significantly impaired. From this viewpoint, there is a strong demand for a dye that does not cause a bronzing phenomenon. In addition, in this specification, the pigment | dye which does not produce this bronzing phenomenon is described as a pigment | dye which is excellent in bronzing property.

  In the future, in order to expand the field of use of ink jet recording, further improvement in light resistance, gas resistance, moisture resistance, water resistance, bronzing resistance and the like is strongly demanded for ink jet recorded images. In addition to this, a black image is required to have excellent color rendering properties. A phenomenon in which the hue appears to change depending on the type of the light source is referred to as color rendering, but generally this phenomenon is likely to occur in black dyed matter or recorded matter. In the field of dyeing processing, it is common to use a compound having absorption at a long wavelength as a method for improving color rendering properties. For example, Patent Document 6 and Non-Patent Document 1 disclose these methods.

  Various hue inks are prepared from various pigments, of which black ink is an important ink used for both monocolor and full color images. Many pigments for these black inks have been proposed to date, but they have not yet provided a pigment that sufficiently satisfies the demands of the market. Many of the proposed dyes are azo dyes, of which C.I. I. Disazo dyes such as Food Black 2 have problems such as poor water resistance and moisture resistance, insufficient light resistance and gas resistance, and high color rendering. A polyazo dye having an extended conjugated system generally has problems such as low water solubility, easily causing a bronzing phenomenon in which a recorded image has a partially metallic luster, and insufficient light resistance and gas resistance. Similarly, many azo metal-containing dyes that have been proposed have good light resistance, but they contain metal ions, which are undesirable for biological safety and environmental problems, and have extremely low gas resistance. There are problems such as.

  As a black compound (black pigment) for ink jet recording improved with respect to gas resistance, which has become the most important issue in recent years, for example, the compounds described in Patent Document 1 can be mentioned. Although the gas resistance of these compounds has been improved, they do not fully meet market demands. Further, azo compounds having a benzimidazolopyridone skeleton, which is one of the characteristics of the black pigment of the present invention, are disclosed in Patent Documents 3 to 5 and the like. Patent Documents 3 and 4 disclose that a trisazo compound and a water-soluble black compound are used for inkjet recording. Patent Documents 5 and 8 disclose that a tetrakisazo compound and a water-soluble black compound are used for inkjet recording.

International Publication No. 2005/054374 International Publication No. 2004/050768 International Publication No. 2007/077931 International Publication No. 2009/069279 JP 2008-169374 A Japanese Patent Laid-Open No. 01-284562 JP 2004-75719 A International Publication 2012/081640 International Publication No. 2014/132926

Processing Technology Vol. 31, No. 9, 1996, 599-602

  The present invention is particularly excellent in ozone gas resistance, excellent in light resistance and moisture resistance, extremely high in print density, excellent in bronzing resistance, color rendering, and low in saturation when recorded on inkjet dedicated paper. Another object of the present invention is to provide a pigment having a high-quality black hue, and an ink composition containing the pigment, particularly a black ink composition for inkjet recording.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific azo compound can solve the above problems, and have completed the present invention.

［式（１）中、
Ｒ¹は、（Ｃ１〜Ｃ４）アルキル基；又はカルボキシ基で置換された（Ｃ１〜Ｃ４）アルキル基；を表し、
Ｒ²はシアノ基；を表し、
Ｒ³及びＲ⁴は、それぞれ独立して、水素原子；（Ｃ１〜Ｃ４）アルコキシ基；又は、スルホ基；を表し、
Ｒ⁵は、ヒドロキシ基、スルホ基およびカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された（Ｃ１〜Ｃ４）アルキルチオ基を表し、
Ｒ⁶は、ヒドロキシ基、スルホ基およびカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された（Ｃ１〜Ｃ４）アルキルチオ基を表し、
Ｒ⁷は、スルホ（Ｃ１〜Ｃ４）アルコキシ基を表し、
Ｒ⁸は、カルボキシ（Ｃ２〜Ｃ４）アルキルカルボニルアミノ基；又は２−カルボキシフェニルカルボニルアミノ基；（Ｃ１〜Ｃ４）アルキルスルホニルアミノ基；又は４−メチルフェニルスルホニルアミノ基
を表し、
Ｒ⁹は（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基であり、
Ｒ¹⁰は、メチル基；を表し、
Ｒ¹¹〜Ｒ¹³は、それぞれ独立して水素原子；カルボキシ基；スルホ基；ヒドロキシ基；アセチルアミノ基；ハロゲン原子；シアノ基；ニトロ基；スルファモイル基；（Ｃ１〜Ｃ４）アルキル基；（Ｃ１〜Ｃ４）アルコキシ基；ヒドロキシ基、（Ｃ１〜Ｃ４）アルコキシ基、スルホ基およびカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された（Ｃ１〜Ｃ４）アルコキシ基；（Ｃ１〜Ｃ４）アルキルスルホニル基；、又はヒドロキシ基、スルホ基およびカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された（Ｃ１〜Ｃ４）アルキルスルホニル基；を表す。である。］
２）
上記式（１）において、
Ｒ¹は、（Ｃ１〜Ｃ４）アルキル基；又はカルボキシ基で置換された（Ｃ１〜Ｃ４）アルキル基；を表し、
Ｒ²はシアノ基を表し、
Ｒ³及びＲ⁴は、それぞれ独立して、水素原子；（Ｃ１〜Ｃ４）アルコキシ基；又は、スルホ基；を表し、
Ｒ⁵は、ヒドロキシ基、スルホ基およびカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された（Ｃ１〜Ｃ４）アルキルチオ基を表し、
Ｒ⁶は、ヒドロキシ基、スルホ基およびカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された（Ｃ１〜Ｃ４）アルキルチオ基を表し、
Ｒ⁷は、スルホ（Ｃ１〜Ｃ４）アルコキシ基を表し、
Ｒ⁸は、カルボキシ（Ｃ２〜Ｃ４）アルキルカルボニルアミノ基；又は２−カルボキシフェニルカルボニルアミノ基
を表し、
Ｒ⁹は（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基であり、
Ｒ¹⁰は、メチル基；を表し、
Ｒ¹¹〜Ｒ¹³は、水素原子；スルホ基；又はニトロ基；を表し、
Ｒ¹¹〜Ｒ¹³のうち少なくとも１つがニトロ基；である
上記１）に記載のアゾ化合物若しくはその互変異性体、又はそれらの塩、
３）
上記式（１）において、
Ｒ¹がメチル基；、
Ｒ²がシアノ基；、
Ｒ³がメトキシ基；、
Ｒ⁴がスルホ基；、
Ｒ⁵がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁶がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁷がスルホ（Ｃ１〜Ｃ４）アルコキシ基；、
Ｒ⁸がカルボキシ（Ｃ２〜Ｃ４）アルキルカルボニルアミノ基；
Ｒ⁹が（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基；
Ｒ¹⁰がメチル基；
Ｒ¹¹乃至Ｒ¹³のうち、少なくとも１つがニトロ基、それ以外の２つがそれぞれ独立にスルホ基、又は水素原子である
上記１）又は２）に記載のアゾ化合物若しくはその互変異性体、又はそれらの塩、
４）
上記式（１）において、
Ｒ¹がメチル基；、
Ｒ²がシアノ基；、
Ｒ³がメトキシ基；、
Ｒ⁴がスルホ基；、
Ｒ⁵がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁶がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁷がスルホ（Ｃ１〜Ｃ４）アルコキシ基；、
Ｒ⁸がカルボキシエチルカルボニルアミノ基；
Ｒ⁹が（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基；
Ｒ¹⁰がメチル基；
Ｒ¹¹乃至Ｒ¹³がニトロ基、スルホ基、又は水素原子である
上記１）乃至３）のいずれか一項に記載のアゾ化合物若しくはその互変異性体、又はそれらの塩、
５）
上記１）乃至４）のいずれか一項に記載のアゾ化合物若しくはその互変異性体、又はそれらの塩を、色素として少なくとも１種類含有する水性インク組成物、
６）
水溶性有機溶剤をさらに含有する上記５）に記載の水性インク組成物、
７）
上記５）又は６）に記載のインク組成物をインクとして用い、該インクのインク滴を記録信号に応じて吐出させて被記録材に記録を行うインクジェット記録方法、
８）
被記録材が情報伝達用シートである上記７）に記載のインクジェット記録方法、
９）
情報伝達用シートが多孔性白色無機物を含有するインク受容層を有するシ−トである上記８）に記載のインクジェット記録方法。
１０）
上記５）又は６）に記載のインク組成物を含む容器を装填したインクジェットプリンタ。
１１）
ａ）上記１）乃至４）のいずれか一項に記載のアゾ化合物若しくはその互変異性体、又はそれらの塩、又は
ｂ）上記５）又は６）に記載の水性インク組成物
によって着色された着色体、に関する。 That is, the present invention
1)
An azo compound represented by the following formula (1) or a tautomer thereof, or a salt thereof;

[In Formula (1),
R ¹ represents a (C1-C4) alkyl group; or a (C1-C4) alkyl group substituted with a carboxy group;
R ² represents a cyano group;
R ³ and R ⁴ each independently represent a hydrogen atom; a (C1-C4) alkoxy group; or a sulfo group;
R ⁵ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁶ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁷ represents a sulfo (C1-C4) alkoxy group,
R ⁸ represents a carboxy (C2-C4) alkylcarbonylamino group; or a 2-carboxyphenylcarbonylamino group; a (C1-C4) alkylsulfonylamino group; or a 4-methylphenylsulfonylamino group,
R ⁹ is a (C1-C4) alkylcarbonylamino group,
R ¹⁰ represents a methyl group;
R ^{11 to} R ¹³ each independently represent a hydrogen atom; a carboxy group; a sulfo group; a hydroxy group; an acetylamino group; a halogen atom; a cyano group; a nitro group; a sulfamoyl group; (C1 to C4) an alkyl group; (C4) alkoxy group; (C1-C4) alkoxy group substituted with at least one group selected from the group consisting of hydroxy group, (C1-C4) alkoxy group, sulfo group and carboxy group; (C1-C4) An alkylsulfonyl group; or a (C1-C4) alkylsulfonyl group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group. It is. ]
2)
In the above formula (1),
R ¹ represents a (C1-C4) alkyl group; or a (C1-C4) alkyl group substituted with a carboxy group;
R ² represents a cyano group,
R ³ and R ⁴ each independently represent a hydrogen atom; a (C1-C4) alkoxy group; or a sulfo group;
R ⁵ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁶ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁷ represents a sulfo (C1-C4) alkoxy group,
R ⁸ represents a carboxy (C2-C4) alkylcarbonylamino group; or a 2-carboxyphenylcarbonylamino group,
R ⁹ is a (C1-C4) alkylcarbonylamino group,
R ¹⁰ represents a methyl group;
R ^{11 to} R ¹³ represent a hydrogen atom; a sulfo group; or a nitro group;
The azo compound or the tautomer thereof according to the above 1), or a salt thereof, wherein at least one of R ^{11 to} R ¹³ is a nitro group;
3)
In the above formula (1),
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfo (C1-C4) alkoxy group;
R ⁸ is a carboxy (C 2 -C 4) alkylcarbonylamino group;
R ⁹ is a (C1-C4) alkylcarbonylamino group;
R ¹⁰ is a methyl group;
The azo compound or the tautomer thereof according to 1) or 2) above, wherein at least one of R ^{11 to} R ¹³ is a nitro group and the other two are each independently a sulfo group or a hydrogen atom, or Salt of
4)
In the above formula (1),
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfo (C1-C4) alkoxy group;
R ⁸ is a carboxyethylcarbonylamino group;
R ⁹ is a (C1-C4) alkylcarbonylamino group;
R ¹⁰ is a methyl group;
The azo compound or a tautomer thereof according to any one of 1) to 3), or a salt thereof, wherein R ^{11 to} R ¹³ are a nitro group, a sulfo group, or a hydrogen atom,
5)
An aqueous ink composition containing at least one kind of the azo compound according to any one of 1) to 4) or a tautomer thereof, or a salt thereof;
6)
The water-based ink composition as described in 5) above, further containing a water-soluble organic solvent,
7)
An ink jet recording method for recording on a recording material by using the ink composition according to 5) or 6) as an ink, and discharging ink droplets of the ink in accordance with a recording signal;
8)
The inkjet recording method according to 7) above, wherein the recording material is an information transmission sheet,
9)
8. The ink jet recording method according to 8) above, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance.
10)
An ink jet printer loaded with a container containing the ink composition described in 5) or 6) above.
11)
a) The azo compound according to any one of 1) to 4) or a tautomer thereof, or a salt thereof, or b) the water-based ink composition according to 5) or 6) above. It relates to a colored body.

  The azo compound of the present invention or a tautomer thereof, or a salt thereof, and an ink composition containing the same have high storage stability and are preferably used as an ink for ink jet recording, and further recorded on ink jet dedicated paper. In this case, the printing density is very high, the color rendering property is excellent, the saturation is low, the color has a high-quality black hue, and the (ozone) gas resistance is particularly excellent. Therefore, the ink composition containing the azo compound of the present invention or a tautomer thereof, or a salt thereof is extremely useful as a black ink for inkjet recording.

Hereinafter, the present invention will be described in detail.
For the sake of convenience, in the present specification, the “azo compound of the present invention”, including all of the “azo compound of the present invention or a tautomer thereof, or a salt thereof”, will be simply described below.
Here, examples of the tautomer include structures represented by the following formulas (2) and (3). In formulas (2) and (3), R ^{1 to} R ¹³ have the same meaning as in formula (1).

In the above formula (1), R ¹ represents a (C1-C4) alkyl group; or a (C1-C4) alkyl group substituted with a carboxy group.

Examples of the (C1 to C4) alkyl group for R ¹ include a linear or branched unsubstituted group, and a linear group is preferable. Specific examples thereof include, for example, straight chain such as methyl group, ethyl group, n-propyl group and n-butyl group; branched chain such as isopropyl group, isobutyl group, sec-butyl group and tert-butyl group And the like. Preferable specific examples include a methyl group and an n-propyl group, and a methyl group is more preferable.

Examples of the (C1 to C4) alkyl group substituted with a carboxy group in R ¹ include those obtained by substituting a carboxy group for any carbon atom of the unsubstituted (C1 to C4) alkyl group. The substitution position of the carboxy group is not particularly limited, but it is preferably substituted at the end of the alkyl group, and the number of substitution of the carboxy group is 1 or 2, preferably 1. Specific examples include a carboxymethyl group and a 2-carboxyethyl group. A preferred specific example is a carboxymethyl group.

R ¹ is preferably a (C1 to C4) alkyl group or a (C1 to C4) alkyl group substituted with a carboxy group, but more preferably a (C1 to C4) alkyl group.
More preferably, it is a methyl group or an n-propyl group. Particularly preferred is a methyl group.

In the formula (1), R ² represents a cyano group.

In the formula (1), R ³ and R ⁴ each independently represent a hydrogen atom; a (C1-C4) alkoxy group; or a sulfo group.

Examples of the (C1 to C4) alkoxy group in R ³ and R ⁴ include a linear or branched unsubstituted group, and a linear group is preferable. Specific examples include straight chain groups such as methoxy group, ethoxy group, n-propoxy group and n-butoxy group; branched chains such as isopropoxy group, isobutoxy group, sec-butoxy group and tert-butoxy group; Etc. In these, a methoxy group is more preferable.

As R ³ and R ⁴ , one is preferably a methoxy group, the other is a sulfo group, or one of them is a hydrogen atom, and the other is a combination of a sulfo group. More preferably, one is a combination of a methoxy group and the other is a sulfo group.
The substitution position of R ³ and R ⁴ is not particularly limited, but when either one is a hydrogen atom and the other is a sulfo group, the sulfo group is any of the four carbon atoms that do not constitute the imidazole ring of the benzimidazolopyridone ring. It is preferable to substitute two.

The compound represented by the above formula (1) of the present invention may be used as a mixture containing at least two kinds of positional isomers at the substitution positions of R ³ and R ⁴ from the viewpoint of ease of synthesis and low cost. good.

As a preferable combination of R ^{1 to} R ⁴ in the above formula (1), R ¹ is a (C1-C4) alkyl group (preferably a methyl group or an n-propyl group, more preferably a methyl group), and R ² is a cyano group. A group in which R ³ is a hydrogen atom or a methoxy group (preferably a methoxy group), and R ⁴ is a sulfo group.

In the above formula (1), R ⁵ and R ⁶ each independently represent a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxyl group. .

As the substituent in R ⁵ and R ^6, the (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group includes (C1-C4) Those having these substituents at any carbon atom in the alkylthio group are exemplified. The number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but is preferably substituted with a carbon atom other than the carbon atom to which the sulfur atom in the alkylthio group is bonded.
Specific examples thereof include 2-hydroxyethylthio group, 2-hydroxypropylthio group, 3-hydroxypropylthio group, 2-sulfoethylthio group, 3-sulfopropylthio group, 2-carboxyethylthio group, 3 -Carboxypropylthio group, 4-carboxybutylthio group, etc. are mentioned.

Among the above, preferable R ⁵ and R ⁶ include a sulfo (C1 to C4) alkylthio group or a carboxy (C1 to C4) alkylthio group, more preferably a sulfo (C1 to C4) alkylthio group, and 3-sulfopropyl. A thio group is particularly preferred.

In the formula (1), ^{R 7} represents a sulfo (C1 -C4) alkoxy groups.

In the above formula (1), ^{R 8} is carboxy (C2-C4) alkylcarbonylamino group; represents a or 4-methyl-phenylsulfonylamino group; or 2-carboxyphenyl carbonyl amino group; (C1 -C4) alkylsulfonylamino group .

Carboxy (C2-C4) alkylcarbonylamino group in the above R ^8, include those any carboxy group to a carbon atom of straight-chain or unsubstituted (C2-C4) alkylcarbonylamino group branched chain is substituted It is done. Specific examples thereof include 2-carboxyethylcarbonylamino group, 3-carboxy n-propylcarbonylamino group, 4-carboxy n-butylcarbonylamino group, and 2-carboxyethylcarbonylamino group is more preferable.

The (C1-C4) alkyl moiety of the (C1-C4) alkylsulfonylamino group in R ⁸ represents the same meaning as the (C1-C4) alkyl group in R ¹ .

In the above formula (1), R ⁹ represents a (C1-C4) alkylcarbonylamino group.

Examples of the (C1 to C4) alkylcarbonylamino group for R ⁹ include straight chain or branched chain unsubstituted alkyl groups, with straight chain groups being preferred. Specific examples thereof include straight chain such as acetylamino group (methylcarbonylamino group), propionylamino group (ethylcarbonylamino group), n-propylcarbonylamino group, n-butylcarbonylamino group; isopropylcarbonylamino Group, an isobutylcarbonylamino group, a sec-butylcarbonylamino group, a branched chain such as a pivaloylamino group (tert-butylcarbonylamino group); and the like, and an acetylamino group is more preferable.

In the above formula (1), R ¹⁰ represents a methyl group.

R ^{11 to} R ¹³ are each independently hydrogen atom; carboxy group; sulfo group; hydroxy group; acetylamino group; halogen atom; cyano group; nitro group; sulfamoyl group; (C1 to C4) alkyl group; -C4) alkoxy group; (C1-C4) alkoxy group substituted by at least one group selected from the group consisting of hydroxy group, (C1-C4) alkoxy group, sulfo group and carboxy group; (C1-C4) ) An alkylsulfonyl group; or a (C1-C4) alkylsulfonyl group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group.

The (C1 to C4) alkoxy group substituted with at least one group selected from the group consisting of a hydroxy group, a (C1 to C4) alkoxy group, a sulfo group and a carboxy group in R ^{11 to} R ¹³ includes (C1 -C4) What has these substituents in the arbitrary carbon atoms in an alkoxy group is mentioned. The number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but is preferably substituted with a carbon atom other than the carbon atom to which the oxygen atom in the alkoxy group is bonded. Specific examples thereof include, for example, 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy, hydroxy (C1-C4) alkoxy groups; 2-sulfoethoxy, 3-sulfopropoxy, 4-sulfobutoxy, sulfo ( C1-C4) alkoxy group; 2-carboxyethoxy, 3-carboxypropoxy, 4-carboxybutoxy and the like, carboxy (C1-C4) alkoxy group;
Examples of the (C1 to C4) alkylsulfonyl group for R ^{11 to} R ¹³ include linear or branched ones, and linear ones are preferred. Specific examples thereof include linear ones such as methylsulfonyl, ethylsulfonyl, n-propylsulfonyl and n-butylsulfonyl; branched ones such as isopropylsulfonyl and isobutylsulfonyl;
Of the above, methylsulfonyl, ethylsulfonyl, and isopropylsulfonyl are preferable, and methylsulfonyl is particularly preferable.
As the substituent in R ¹¹ to R ¹³ , the (C1 to C4) alkylsulfonyl group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group includes the above (C1 to C1). C4) The above-mentioned groups are substituted on any carbon atom in the alkylsulfonyl group, and the number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited. Specific examples include hydroxy-substituted compounds such as hydroxyethylsulfonyl and 2-hydroxypropylsulfonyl; sulfo-substituted compounds such as 2-sulfoethylsulfonyl and 3-sulfopropylsulfonyl; 2-carboxyethylsulfonyl and 3-carboxypropylsulfonyl. Carboxy-substituted ones such as;

Among the above, preferable R ¹¹ includes a hydrogen atom, a carboxy group, a sulfo group, a nitro group, a chlorine atom, a methyl group, a methoxy group, and a (C1 to C4) alkylsulfonyl group. A carboxy group, a sulfo group, a nitro group, a chlorine atom, a (C1-C4) alkylsulfonyl group, or a methyl group and a methoxy group are more preferable, and a hydrogen atom and a sulfo group are particularly preferable.

Among the above, preferable R ¹² is a hydrogen atom, a carboxy group, a sulfo group, a nitro group, a chlorine atom, a methyl group, a methoxy group, a sulfamoyl group, a (C1 to C4) alkylsulfonyl group, or a carboxy (C1 to C4) alkyl. A sulfonyl group, a sulfo (C1-C4) alkylsulfonyl group, a hydrogen atom or an electron-withdrawing substituent such as a carboxy group, a sulfo group, a nitro group, a chlorine atom, a sulfamoyl group, a (C1-C4) alkylsulfonyl group, A carboxy (C1 to C4) alkylsulfonyl group, a sulfo (C1 to C4) alkylsulfonyl group, or a methyl group or a methoxy group is more preferable, and a sulfo group, a nitro group, a methyl group, a methoxy group, a sulfamoyl group, a sulfopropylsulfonyl group, A carboxyethylsulfonyl group is more preferred, and a nitro group is particularly preferred. Preferred.

Among these, preferable R ¹³ includes a hydrogen atom, a carboxy group, a sulfo group, a methoxy group, a nitro group, a chlorine atom, and a (C1 to C4) alkylsulfonyl group, and is a hydrogen atom or an electron-withdrawing substituent. A carboxy group, a sulfo group, a nitro group, a chlorine atom, a (C1-C4) alkylsulfonyl group, or a methoxy group is more preferable, and a hydrogen atom is particularly preferable.

In the formula (1), more preferable R ^{11 to} R ¹³ can specify the substitution position and the like.
That is, in the benzene ring substituted by R ^{11 to} R ^13, when the substitution position of the azo group is 1-position, R ¹¹ is 2-position, R ¹² is 3-position or 4-position, and R ¹³ is 5-position Alternatively, those substituted at the 6-position are preferred.

Specific examples of preferable combinations in the above formula (1) include the following combinations (i) to (v). (Ii) or (iii) is more preferable, and (iv) or (v) is more preferable.
(I)
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a hydrogen atom; or a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is substituted by a sulfo group or a carboxy group (C1 -C4) alkylthio groups;,
A (C1-C4) alkylthio group substituted with a sulfo group or a carboxy group for R ⁶ ;
R ⁷ is a sulfo (C1-C4) alkoxy group;
R ⁸ is a carboxy (C2-C4) alkylcarbonylamino group;
R ⁹ is a (C1-C4) alkylcarbonylamino group;
R ¹⁰ is a methyl group;
R ¹¹ to R ¹³ are each independently a hydrogen atom; a sulfo group; a nitro group;
(Ii)
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfo (C1-C4) alkoxy group;
R ⁸ is a carboxy (C2-C4) alkylcarbonylamino group;
R ⁹ is a (C1-C4) alkylcarbonylamino group;
R ¹⁰ is a methyl group,
R ¹¹ is a nitro group,
R ¹² is a sulfo group,
R ¹³ is a hydrogen atom,
(Iii)
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfo (C1-C4) alkoxy group;
R ⁸ is a carboxy (C2-C4) alkylcarbonylamino group;
R ⁹ is an acetylamino group;
R ¹⁰ is a methyl group,
R ¹¹ is a sulfo group,
R ¹² is a nitro group,
R ¹³ is a hydrogen atom (iv)
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfopropoxy group; or a sulfobutoxy group;
R ⁸ is a carboxy (C2-C4) alkylcarbonylamino group;
R ⁹ is an acetylamino group;
R ¹⁰ is a methyl group,
R ¹¹ is a nitro group,
R ¹² is a sulfo group,
R ¹³ is a hydrogen atom (v)
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfopropoxy group; or a sulfobutoxy group;
R ⁸ is a 2-carboxyethylcarbonylamino group;
R ⁹ is an acetylamino group;
R ¹⁰ is a methyl group,
R ¹¹ is a sulfo group,
R ¹² is a nitro group,
R ¹³ is a hydrogen atom,
Is a combination.

  The compound which combined the preferable thing described about the various substituents in the said Formula (1), its combination, its substitution position, etc. is more preferable, and what combined the more preferable things is still more preferable. The same applies to preferable combinations, preferable combinations, and more preferable combinations.

The tetrakisazo compound of the present invention represented by the above formula (1) can be synthesized, for example, by the following method. Moreover, the structural formula of the compound in each process shall be represented with the form of a free acid.
In the following formulas (4) to (11), R ^{1 to} R ¹³ represent the same meaning as in the above formula (1).
A compound represented by the following formula (4) is diazotized by a conventional method, and the obtained diazo compound and a compound represented by the following formula (5) are subjected to a coupling reaction by a conventional method, and represented by the following formula (6). To obtain the compound.

  The obtained compound represented by the above formula (6) is diazotized by a conventional method, and then the obtained diazo compound and a compound represented by the following formula (7) are subjected to a coupling reaction by a conventional method. The compound represented by (8) is obtained.

  The obtained compound represented by the above formula (8) is diazotized by a conventional method, and then the obtained diazo compound and a compound represented by the following formula (9) are subjected to a coupling reaction by a conventional method. The compound represented by (10) is obtained.

  By diazotizing the obtained compound represented by the above formula (10) by a conventional method, the resulting diazo compound and a compound represented by the following formula (11) are subjected to a coupling reaction by a conventional method. The azo compound of the present invention represented by the above formula (1) can be obtained.

  In addition, the compound represented by the said Formula (11) is compoundable according to the method of the said patent document 3.

Although it does not specifically limit as a suitable specific example of the azo compound of this invention represented by the said Formula (1), The compound shown by the structural formula given to the following Table 1 thru | or 3 etc. are mentioned.
In each table, functional groups such as sulfo group and carboxy group are described in the form of free acid for convenience. In the following formula, Ac represents an acetyl group.

The diazotization of the compound represented by the above formula (4) is carried out by a method known per se, for example, nitrite, for example, in an inorganic acid medium at a temperature of, for example, -5 to 30 ° C, preferably 0 to 15 ° C. It is carried out using an alkali metal nitrite such as sodium nitrite.
Coupling of the diazotized compound of the compound represented by the above formula (4) and the compound represented by the above formula (5) is also carried out under known conditions. It is advantageous to carry out in water or an aqueous organic medium, for example at a temperature of -5 to 30 ° C, preferably 0 to 25 ° C, and at an acidic to neutral pH value, for example pH 1-6. Since the diazotization reaction liquid is acidic and the reaction system is further acidified by the progress of the coupling reaction, the pH value is adjusted to a preferable pH condition of the reaction liquid by adding a base. Examples of the base that can be used include alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate, acetates such as sodium acetate, ammonia, and organic amines. .
The compound represented by the above formula (4) and the compound represented by the above formula (5) are used in a substantially stoichiometric amount.

The diazotization of the compound represented by the above formula (6) is carried out by a method known per se, for example, nitrite, for example, in an inorganic acid medium at a temperature of, for example, -5 to 40 ° C, preferably 5 to 30 ° C. It is carried out using an alkali metal nitrite such as sodium nitrite.
Coupling of the diazotized compound of the compound represented by the above formula (6) and the compound represented by the above formula (7) is also carried out under known conditions. It is advantageous to carry out the reaction in water or an aqueous organic medium, for example at a temperature of -5 to 40 ° C, preferably 10 to 30 ° C, and at an acidic to neutral pH value, for example pH 2-7. Since the diazotization reaction liquid is acidic and the reaction system is further acidified by the progress of the coupling reaction, the pH value is adjusted to a preferable pH condition of the reaction liquid by adding a base. The same base as described above can be used.
The compound represented by formula (6) and the compound represented by formula (7) are used in a substantially stoichiometric amount.

The diazotization of the compound represented by the above formula (8) is carried out by a method known per se, for example, a nitrite such as nitrous acid in an inorganic acid medium, for example, at a temperature of -5 to 50 ° C, preferably 5 to 40 ° C. It is carried out using an alkali metal nitrite such as sodium nitrate.
Coupling of the diazotized compound of the compound represented by the above formula (8) and the compound represented by the above formula (9) is also carried out under known conditions. It is advantageous to carry out the reaction in water or an aqueous organic medium, for example at a temperature of -5 to 50 ° C, preferably 10 to 40 ° C, and at an acidic to neutral pH value, for example pH 2-7. Since the diazotization reaction liquid is acidic and the reaction system is further acidified by the progress of the coupling reaction, the pH value is adjusted to a preferable pH condition of the reaction liquid by adding a base. The same base as described above can be used.
The compound represented by the above formula (8) and the compound represented by the above formula (9) are used in a substantially stoichiometric amount.

The diazotization of the compound represented by the above formula (10) is also carried out by a method known per se, for example, a nitrite such as nitrous acid at a temperature of, for example, -5 to 50 ° C, preferably 10 to 40 ° C in an inorganic acid medium. It is carried out using an alkali metal nitrite such as sodium.
Coupling of the diazotized compound of the compound represented by the above formula (10) and the compound represented by the above formula (11) is also carried out under known conditions. It is advantageous to carry out the reaction in water or an aqueous organic medium, for example at a temperature of -5 to 50 ° C, preferably 10 to 40 ° C, and at a weakly acidic to alkaline pH value. It is preferably carried out at a weakly acidic to weakly alkaline pH value, for example, pH 5 to 10, and the pH value is adjusted by adding a base. The same base as described above can be used.
The compound represented by the above formula (10) and the compound represented by the above formula (11) are used in a substantially stoichiometric amount.

The salt of the azo compound represented by the above formula (1) is a salt with an inorganic or organic cation. Among them, examples of the salt with an inorganic cation include alkali metal salts, alkaline earth metal salts, and ammonium salts. Preferred inorganic salts are lithium, sodium, potassium salts, and ammonium salts. Examples of the salt with an organic cation include, but are not limited to, a salt with a quaternary ammonium ion represented by the following formula (12).
In addition, the free acid of the azo compound of the present invention, its tautomer, and various salts thereof may be a mixture. For example, any combination such as a mixture of sodium salt and ammonium salt, a mixture of free acid and sodium salt, a mixture of lithium salt, sodium salt, and ammonium salt may be used. Depending on the type of salt, the physical properties such as solubility may differ, and if necessary, the type of salt is selected as appropriate, or if multiple salts are included, the ratio is changed to meet the purpose. A mixture having physical properties can also be obtained.

In the above formula (12), Z ¹ , Z ² , Z ³ , and Z ⁴ are each independently selected from the group consisting of a hydrogen atom, an unsubstituted alkyl group, a hydroxyalkyl group, and a hydroxyalkoxyalkyl group. Represents a group, at least one of which is a group other than a hydrogen atom.
Specific examples of the alkyl group of Z ^{1 to} Z ⁴ in the above formula (12) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl. Specific examples of the hydroxyalkyl group include hydroxymethyl group, hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 2-hydroxy group. Examples of the hydroxyalkoxyalkyl group include hydroxyethoxymethyl group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, and 2-hydroxyethoxypropyl. Group, 4-hydroxyethoxybutyl group, 3-hydroxyethyl Examples thereof include hydroxy (C1-C4) alkoxy (C1-C4) alkyl groups such as a toxibutyl group and 2-hydroxyethoxybutyl group. Among these, a hydroxyethoxy (C1-C4) alkyl group is preferable. Particularly preferred are hydrogen atom; methyl group; hydroxymethyl group, hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 2-hydroxybutyl group. Hydroxy (C1-C4) alkyl group such as; hydroxyethoxymethyl group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, 2-hydroxyethoxypropyl group, 4-hydroxyethoxybutyl group, 3-hydroxyethoxybutyl Group, hydroxyethoxy (C1-C4) alkyl group such as 2-hydroxyethoxybutyl group; and the like.

Specific examples of combinations of Z ¹ , Z ² , Z ³ and Z ^{4 in} the preferred compound represented by the above formula (12) are shown in Table 4 below.

As a method of synthesizing a desired salt of the azo compound represented by the above formula (1) of the present invention, a desired inorganic salt is obtained after completion of the final step in the synthesis reaction of the compound represented by the above formula (1). Or a method of salting out by adding an organic quaternary ammonium salt to the reaction solution; obtained after adding a mineral acid such as hydrochloric acid to the reaction solution and isolating the azo compound from the reaction solution in the form of a free acid. The free acid is washed with water, acidic water, an aqueous organic medium or the like as necessary to remove impurities such as attached inorganic salts, and again in the aqueous medium (preferably in water). And a method of forming a salt by adding an organic base corresponding to the desired inorganic base or the above-described quaternary ammonium salt. By such a method, the salt of the target azo compound can be obtained in the form of a solution or a precipitated solid. Here, acidic water refers to water obtained by dissolving a mineral acid such as sulfuric acid or hydrochloric acid or an organic acid such as acetic acid in water. The aqueous organic medium is an admixture of water and an organic substance and / or an organic solvent that are miscible with water.
Examples of the water-miscible organic substance and organic solvent include water-soluble organic solvents described later.
Examples of inorganic salts used when the azo compound represented by the above formula (1) is used as a desired salt include halogen salts of alkali metals such as lithium chloride, sodium chloride and potassium chloride; lithium carbonate, sodium carbonate, carbonate Alkali metal carbonates such as potassium; Alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide; Halogen salts of ammonium ions such as ammonium chloride and ammonium bromide; Ammonium hydroxide (ammonia water) And the like.
Examples of the organic cation salt include halogen salts of quaternary ammonium ions represented by the above formula (12) such as diethanolamine hydrochloride and triethanolamine hydrochloride.

  The ink composition of the present invention will be described. By making the azo compound represented by the above formula (1) of the present invention into an aqueous composition containing the compound, it is possible to dye a material made of cellulose. In addition, it is possible to dye materials having a carbonamide bond, and it can be widely used for dyeing leather, fabrics, paper, and the like. On the other hand, a typical use of the compound of the present invention is an ink composition dissolved in a liquid medium, and is preferably used as an ink composition for inkjet recording.

  The reaction liquid containing the compound represented by the above formula (1), for example, the reaction liquid after the final step in the synthesis reaction of the compound represented by the above formula (1) is directly used for the production of the ink composition. I can do things. However, the reaction solution is dried, for example, spray-dried; the reaction solution is salted out by adding inorganic salts such as sodium chloride, potassium chloride, calcium chloride, sodium sulfate; the reaction solution is treated with hydrochloric acid, sulfuric acid The compound is isolated by a method of acid precipitation by adding a mineral acid such as nitric acid or the like; or a method of acid precipitation by a combination of the above-mentioned salting out and acid precipitation; Compositions can also be prepared. The azo compound of the present invention is preferably used after being isolated.

  The ink composition of the present invention is usually 0.1 to 20% by mass, preferably 1 to 10% by mass, more preferably 2 to 8% by mass, using the azo compound represented by the above formula (1) of the present invention as a pigment. % Water-based ink composition. The ink composition of the present invention is prepared using water as a medium, and may contain a water-soluble organic solvent and an ink preparation agent as necessary within a range that does not impair the effects of the present invention. The water-soluble organic solvent may have a function as a dye-dissolving agent, a drying inhibitor (wetting agent), a viscosity modifier, a penetration accelerator, a surface tension modifier, an antifoaming agent, etc., and the ink composition of the present invention It is preferable to contain them. Examples of the ink preparation agent include antiseptic / antifungal agents, pH adjusters, chelating reagents, rust preventives, water-soluble ultraviolet absorbers, water-soluble polymer compounds, dye solubilizers, antioxidants, and surfactants. These additives may be mentioned. In the ink composition of the present invention, the water-soluble organic solvent is 0 to 30% by mass, preferably 5 to 30% by mass, and the ink preparation agent is 0 to 15% by mass, preferably 0 to 7% by mass, based on the total mass. % May be contained respectively. The remainder other than the above is water. The pH of the ink composition is preferably pH 5 to 11 and more preferably pH 7 to 10 in terms of improving storage stability. Further, the surface tension of the ink composition is preferably 25 to 70 mN / m, and more preferably 25 to 60 mN / m. Furthermore, the viscosity of the ink composition is preferably 30 mPa · s or less, and more preferably 20 mPa · s or less.

In addition to the azo compound of the present invention, the ink composition of the present invention may appropriately contain other toning pigments and the like for the purpose of adjusting the subtle hue of black. Even in such a case, the total mass of the pigment contained in the ink composition of the present invention may be in the above range with respect to the total mass of the ink composition.
Examples of toning dyes include yellow (for example, CI Direct Yellow 34, CI Direct Yellow 58, CI Direct Yellow 86, CI Direct Yellow 132, CI Direct Yellow 161, etc. ), Orange (for example, CI Direct Orange 17, CI Direct Orange 26, CI Direct Orange 29, CI Direct Orange 39, CI Direct Orange 49, etc.), Brown, Scarlet (E.g., CI Direct Red 89), red (e.g., CI Direct Red 62, CI Direct Red 75, CI Direct Red 79, CI Direct Red 80, CI Direct Red 84, CI Direct Red 225, CI Direct Red 226), magenta (for example, CI Direct Red 227), violet, blue, navy, cyan (for example, CI Direct Blue 199, CI Acid Blue 249, etc.), green (for example, Acid Green 1) ), Black (for example, CI Acid Black 2), and other dyes having various hues.
The ink composition of the present invention can be used by blending one or more of these toning dyes as long as the effects obtained by the azo compound of the present invention are not impaired. Even in this case, the total amount of the coloring matter contained in the ink composition may be in the above range. The mixing ratio of the azo compound of the present invention to the toning dye is approximately 20: 1 to 1: 2, preferably 10: 1 to 1: 1, depending on the hue of the toning dye and the like. It is.
When the ink composition of the present invention is used as an ink for ink jet recording, it is preferable to use an ink having a low content of inorganic impurities such as metal cation chloride and sulfate in the azo compound of the present invention. The standard of the content of the inorganic impurities is about 1% by mass or less with respect to the total mass of the pigment. The lower limit may be less than the detection limit of the analytical instrument, that is, 0%. In order to produce the azo compound of the present invention with a small amount of inorganic impurities, for example, a method using a reverse osmosis membrane; a dried product or wet cake of the azo compound of the present invention is treated with alcohol such as methanol, preferably (C1-C4) alcohol and The reaction mixture may be suspended and purified by stirring in a mixed solvent of water, and the precipitate may be desalted by a known method such as filtration and separation, and drying.

Specific examples of the water-soluble organic solvent that can be used for preparing the ink composition of the present invention include (C1-C4) such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, and tert-butanol. Alcohols; carboxylic acid amides such as N, N-dimethylformamide and N, N-dimethylacetamide; 2-pyrrolidone, hydroxyethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N-methylpyrrolidin-2-one and the like Lactam; cyclic ureas such as 1,3-dimethylimidazolidin-2-one and 1,3-dimethylhexahydropyrimido-2-one; acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one Such as ketone or keto alcohol; tetrahydrofuran, dioxane, etc. Ether; ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene Mono-, oligo-, or polyalkylene glycols or thioglycols having C2-C6 alkylene units such as glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol, dithiodiglycol, etc .; trimethylolpropane, glycerin, hexane-1, Polyols such as 2,6-triol (preferably triol); ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol (C1-C4) alkyl ethers of polyhydric alcohols such as monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol) triethylene glycol monomethyl ether, triethylene glycol monoethyl ether; γ-butyrolactone; dimethyl sulfoxide; Is given. These organic solvents may be used alone or in combination of two or more.
The water-soluble organic solvent mentioned above contains substances that are solid at room temperature, such as trimethylolpropane, but these are water-soluble even when they are solid, and when dissolved in water Since it can be used for the same purpose as the water-soluble organic solvent, it is described in the category of the water-soluble organic solvent for the sake of convenience.

  Hereinafter, antiseptic / antifungal agents, pH adjusters, chelating reagents, rust preventives, water-soluble UV absorbers, water-soluble polymer compounds, dye dissolving agents, antioxidants, and surfactants that can be used as ink preparation agents Describe.

  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. These are preferably used in the ink composition in an amount of 0.02 to 1.00% by mass.

Examples of preservatives include organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzothiazole. , Isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, Examples include benzyl bromacetate and inorganic salt compounds.
Specific examples of the organic halogen compound include sodium pentachlorophenol, and specific examples of the pyridine oxide compound include sodium 2-pyridinethiol-1-oxide, and specific examples of the isothiazoline compound. For example, 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 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 and the like. Specific examples of other antiseptic / antifungal agents include anhydrous sodium acetate, sodium sorbate, sodium benzoate, and the like.

  As the pH adjuster, any substance can be used as long as it can control the pH of the ink within a range of about 5 to 11 without adversely affecting the prepared ink. Specific examples thereof include, for example, alkanolamines such as diethanolamine, triethanolamine and N-methyldiethanolamine; hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonium hydroxide (ammonia water) Alkali metal carbonates such as lithium carbonate, sodium carbonate, sodium hydrogen carbonate and potassium carbonate; alkali metal salts of organic acids such as potassium acetate; inorganic bases such as sodium silicate and disodium phosphate.

  Specific examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate and the like.

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

  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.

  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 anionic, cationic, and nonionic surfactants.
Anionic surfactants include alkyl sulfonates, alkyl carboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurates, alkyl sulfates. Polyoxyalkyl 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, alkylaryl sulfonate, Examples thereof include diethylsulfosuccinate, diethylhexylsylsulfosuccinate, and dioctylsulfosuccinate.

  Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, imidazoline derivatives, etc. Is mentioned.

Nonionic surfactants include ethers such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether; Ester systems such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl Acetylene glycol (alcohol) series such as lu-1-hexyn-3-ol; trade name Surfynol 104, 105, 82, 465, Olphine STG, etc. manufactured by Nissin Chemical; Polyglycol ether series (for example, SIGMA-ALDRICH) Manufactured by Tergitol 15-S-7, etc.).
The above ink preparation agents are used alone or in combination.

  The ink composition of the present invention can be obtained by mixing and stirring the above components in an arbitrary order. If desired, the obtained ink composition may be subjected to microfiltration with a membrane filter or the like to remove impurities, and when used for ink jet recording, it is preferable to perform the filtration. The pore diameter of the filter for performing microfiltration is usually 1 μm to 0.1 μm, preferably 0.8 μm to 0.1 μm.

  The ink composition of the present invention can be used in various fields, but is suitable for a water-based ink for writing, a water-based printing ink, an information recording ink, and the like, and is particularly preferably used as an ink for ink-jet recording. It is suitably used in the ink jet recording method of the present invention.

The ink jet recording method of the present invention is a method of performing recording by using the ink composition of the present invention as an ink, ejecting ink droplets of the ink in accordance with a recording signal, and attaching them to a recording material. In the ink jet recording method of the present invention, there are no particular limitations on the ink head, ink nozzles, and the like used for recording, and the ink recording method can be appropriately selected according to the purpose.
This recording method is a known method, for example, a charge control method that ejects ink using electrostatic attraction force; a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezo element; An acoustic ink jet method that irradiates the ink instead of the ink and discharges the ink using the radiation pressure; a thermal ink jet that heats the ink to form bubbles and uses the generated pressure, a so-called bubble jet (registered trademark) method Etc. can be used.

The recording material used in the ink jet recording method of the present invention is not particularly limited. For example, information transmission sheets such as paper and film, fibers and cloths (cellulose, nylon, wool, etc.), leather, and color filter base materials. Among them, an information transmission sheet is preferable.
The information transmission sheet is preferably a surface-treated sheet, specifically, a sheet, a synthetic paper, a film or other base material provided with an ink receiving layer. The ink receiving layer is formed by, for example, impregnating or coating the above-mentioned base material with a cationic polymer; a porous white inorganic substance capable of absorbing a pigment in the ink, such as porous silica, alumina sol, or special ceramics. It is provided by a method such as coating with a hydrophilic polymer such as pyrrolidone on the surface of the substrate.
The information transmission sheet provided with such an ink receiving layer is usually called ink jet dedicated paper (film), glossy paper (film) or the like. Specific examples include Canon Inc., trade name: Professional Photo Paper, Super Photo Paper, or Matt Photo Paper; Seiko Epson Corporation, trade name: Photo Paper (Glossy), PM Matt Paper, Crispia; Japan Hewlett-Packard Co. Made by company, product name Advanced Photo Paper, Premium Plus Photo Paper, Premium Glossy Film or Photo Paper, etc., and are available as commercial products. Of course, plain paper can also be used.

  Among the information transmission sheets described above, it is known that an image recorded on a sheet coated with a porous white inorganic substance has a particularly large discoloration due to ozone gas. However, since the ink composition of the present invention is excellent in ozone gas resistance, a great effect is exhibited even when ink jet recording is performed on such a recording material.

In order to record on a recording material by the ink jet recording method of the present invention, for example, a container containing the above ink composition may be loaded at a predetermined position of an ink jet printer and recorded on the recording material by the above method.
The ink jet recording method of the present invention comprises the black ink composition of the present invention and, for example, the known magenta, cyan, yellow, and as necessary, green, blue (or violet), red (or orange), etc. These ink compositions of the respective colors can also be used in combination.
The ink composition of each color is injected into each container, and each container is 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 black ink composition of the present invention.

The colored body of the present invention is
a) The azo compound according to any one of 1) to 6) or a tautomer thereof, or a salt thereof,
b) the water-based ink composition as described in 7) or 8) above, and
c) A substance colored by any one of the three methods of the ink jet recording method described in 9) above [the three of these a) to c)].
Although there is no restriction | limiting in particular about the substance to be colored, The recording material etc. which are used for said inkjet recording method are mentioned preferably.

The azo compound of the present invention is a black pigment. This compound is easy to synthesize and inexpensive, and has a feature of low saturation, and therefore exhibits a more preferable hue as black. Moreover, since it is excellent in water solubility, the filterability with a membrane filter in the process of producing an ink composition is good.
Further, the ink composition of the present invention containing the azo compound is an aqueous black ink composition, and has good storage stability without solid precipitation, physical property change, color change, etc. after long-term storage.
The image recorded with the ink composition of the present invention is particularly excellent in ozone gas resistance, has a high printing density, excellent bronzing properties, low color rendering, low saturation, and high-quality black hue. Have. Excellent fastness such as light resistance, moisture resistance and water resistance. Further, when used in combination with ink compositions containing magenta, cyan, and yellow pigments, full-color ink jet recording with excellent fastness and storage stability is possible.
As described above, the ink composition containing the azo compound of the present invention can be used as an ink for ink jet recording, a writing instrument, and the like, and has excellent ejection stability. Is preferred.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by the following example.
In the text, “parts” and “%” are based on mass unless otherwise specified.
Each synthesis reaction, crystallization, and the like were performed under stirring unless otherwise specified. In the following formulas, acidic functional groups such as sulfo and carboxy are represented in the form of free acid. The pH value and the reaction temperature in the synthesis reaction are both measured values in the reaction system.
Moreover, the maximum absorption wavelength (λmax) of the synthesized compound was measured in an aqueous solution having a pH of 7 to 8, and the measured value of the measured compound was described in Examples.
The azo compounds of the present invention synthesized in the following examples all showed a solubility of 100 g / liter or more in water.

[(A) Synthesis of dye]
[Example 1]
(Process 1)

  20 parts of succinic anhydride and 34.6 parts of 4-chloro-3-nitroaniline were added to 100 parts of toluene, and the reaction was performed at 100 ° C. for 2 hours. This liquid was cooled to room temperature, and the precipitated solid was filtered and washed with 30 parts of toluene and 400 parts of tap water to obtain 80 parts of a wet cake containing the following formula (13).

(Process 2)
80 parts of the wet cake containing the above formula (13) obtained in the step 1 is dissolved in 110 parts of N-methyl-2-pyrrolidone, and 45.2 parts of sodium 3-mercaptopropanesulfonate and 33.3% of potassium carbonate are dissolved therein. Two parts were added. After the addition, the mixture was heated to 100 to 110 ° C. and reacted at the same temperature for 3 hours. After cooling to 60 ° C., 150 parts of water was added to the reaction solution, and the pH was adjusted to 1.0 to 1.5 by adding 35% hydrochloric acid. After stirring for 30 minutes, the precipitated solid was collected by filtration to obtain 112 parts of a wet cake containing a compound represented by the following formula (14).

(Process 3)
To 200 parts of water, 112 parts of a wet cake of the compound represented by the formula (14) obtained in Example 1 (Step 2) was added, and 4 parts of 25% aqueous sodium hydroxide solution was added and dissolved. 4 parts of activated carbon and 0.2 part of anhydrous iron (III) chloride were added to this solution, and after heating to 60 ° C., 22.6 parts of 80% hydrazine hydrate was added dropwise over about 30 minutes. After heating to 90 ° C., the mixture was reacted at the same temperature for 2 hours. After cooling to 40 ° C., insoluble matters were removed by filtration, and the filtrate was cooled to room temperature. The pH was adjusted to 1.0 to 1.5 by adding 50% sulfuric acid. At this time, the liquid volume was 600 parts. After adding 60 parts of sodium chloride to this liquid and stirring for 30 minutes, the precipitated solid was collected by filtration to obtain 90 parts of a wet cake containing a compound represented by the following formula (15).

(Process 4)
After adding 12.2 parts of sodium 2-amino-5-nitrobenzenesulfonate represented by the following formula (16) to 50 parts of water, the aqueous solution was adjusted to pH 4.0-5.0 by adding 25% aqueous sodium hydroxide solution. Obtained. After adding 18.3 parts of 35% hydrochloric acid, 10.5 parts of 40% aqueous sodium nitrite solution was added and allowed to react for about 30 minutes. To this, 1.5 parts of sulfamic acid was added and stirred for 5 minutes to obtain a diazo reaction liquid.
On the other hand, 29.3 parts of a wet cake containing the compound of the above formula (15) was added to 50 parts of water, and an aqueous solution was obtained at pH 4.0 to 5.0 by adding a 25% aqueous sodium hydroxide solution. This aqueous solution was added dropwise to the diazo reaction solution obtained above over about 5 minutes. After the dropwise addition, the mixture was reacted for 3 hours while maintaining the pH at 4.0 to 6.0 by adding a 15% aqueous sodium carbonate solution, and then sodium chloride was added. The precipitated solid was collected by filtration to obtain 102 parts of a wet cake containing a compound represented by the following formula (17).

(Process 5)
After adding the total amount of the wet cake of the compound represented by the formula (17) obtained in Example 1 (Step 4) to 80 parts of water, pH 6.0 to 7.0 was added by adding a 25% aqueous sodium hydroxide solution. As an aqueous solution was obtained. After adding 16.5 parts of 35% hydrochloric acid, 10.6 parts of 40% aqueous sodium nitrite solution was added and allowed to react for about 30 minutes. 7.5 parts of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid.
On the other hand, after adding 23.8 parts of the compound of the following formula (18) obtained by the method described in International Publication No. 2012/081640 to 100 parts of water, pH 4.0-5. An aqueous solution was obtained as zero. This aqueous solution was added dropwise to the diazo reaction solution obtained above over about 5 minutes. After the dropwise addition, the mixture was reacted for 3 hours while maintaining the pH at 4.0 to 4.5 by adding a 15% aqueous sodium carbonate solution. Sodium chloride was added to this liquid, and the precipitated solid was collected by filtration to obtain 95 parts of a wet cake containing a compound represented by the following formula (19).

(Step 6)
To 100 parts of water, 47.5 parts of a wet cake of the compound represented by the formula (19) obtained in Example 1 (Step 5) was added and dissolved by stirring. After adding 7.8 parts of 35% hydrochloric acid, 2.8 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. The sulfamic acid 0.8 part was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid.
On the other hand, 3.7 parts of the compound of the following formula (20) obtained by the method described in JP-A-2004-083492 is added to 80 parts of water, and pH 6.0-7. An aqueous solution was obtained as zero. This aqueous solution was added dropwise to the diazo reaction solution obtained above over about 5 minutes. After the dropwise addition, the mixture was reacted for 3 hours while maintaining the pH at 3.0 to 4.5 by adding a 15% aqueous sodium carbonate solution. After the pH was adjusted to 7.0 to 7.5 by adding a 25% aqueous sodium hydroxide solution, sodium chloride was added. The precipitated solid was collected by filtration to obtain 33 parts of a wet cake containing a compound represented by the following formula (21).

(Step 7)
In 80 parts of water, 33 parts of a wet cake of the compound represented by the formula (21) obtained in Example 1 (Step 6) was added and dissolved by stirring. After adding 6.3 parts of 35% hydrochloric acid, 2.3 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. 0.5 parts of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid.
On the other hand, to 80 parts of water, 4.0 parts of the compound of the following formula (22) obtained by the method described in International Publication No. 2012/081640 is added, and pH 6.0 to 7 is added by adding 5% aqueous sodium hydroxide solution. Solution was obtained as 0.0. The diazo reaction liquid obtained above was dropped into this aqueous solution at 15 to 30 ° C. over about 30 minutes. At this time, a 15% aqueous sodium carbonate solution was added to maintain the pH of the reaction solution at 6.5 to 7.5, and the reaction was further continued for 2 hours while maintaining the same temperature and pH adjustment. Sodium chloride was added to the reaction solution for salting out, and the precipitated solid was separated by filtration to obtain 20.3 parts of a wet cake. The obtained wet cake was dissolved in 40 parts of water, the pH was adjusted to 7.0 to 7.5 with 35% hydrochloric acid, 400 parts of methanol was added, and the precipitated solid was collected by filtration. The obtained wet cake was again dissolved in 40 parts of water, and then 300 parts of methanol was added. The precipitated solid was separated by filtration and dried to obtain a compound represented by the following formula (23) of the present invention as a black powder as 10.3 parts sodium salt.
λmax: 608 nm.

[Example 2]
(Step 7)
To 80 parts of water, 33 parts of a wet cake of the compound represented by the formula (23) obtained in Example 1 (Step 6) was added and dissolved by stirring. After adding 6.3 parts of 35% hydrochloric acid, 2.3 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. 0.5 parts of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid.
On the other hand, 4.4 parts of the compound of the following formula (24) obtained by the method described in International Publication No. 2012/081640 is added to 80 parts of water, and pH 6.0 to 7 is added by adding 5% aqueous sodium hydroxide solution. Solution was obtained as 0.0. The diazo reaction liquid obtained above was dropped into this aqueous solution at 15 to 30 ° C. over about 30 minutes. At this time, a 15% aqueous sodium carbonate solution was added to maintain the pH of the reaction solution at 6.5 to 7.5, and the reaction was further continued for 2 hours while maintaining the same temperature and pH adjustment. Sodium chloride was added to the reaction solution for salting out, and the precipitated solid was separated by filtration to obtain 20.3 parts of a wet cake. The obtained wet cake was dissolved in 40 parts of water, the pH was adjusted to 7.0 to 7.5 with 35% hydrochloric acid, 400 parts of methanol was added, and the precipitated solid was collected by filtration. The obtained wet cake was again dissolved in 40 parts of water, and then 300 parts of methanol was added. The precipitated solid was separated by filtration and dried to obtain a compound represented by the following formula (25) of the present invention as a black powder as 10.6 parts sodium salt.
λmax: 597 nm.

[(B) Preparation of ink]
The ink composition of the present invention was obtained by using the azo compound [Formula (23)] of the present invention obtained in Example 1 as a pigment and mixing the compositions shown in Table 5 below into a solution. . The obtained ink composition was filtered through a 0.45 μm membrane filter to remove impurities, and a test ink was prepared. The pH of this test ink was in the range of 8.0 to 9.5. In Table 5 below, “surfactant” used was the trade name Surfinol ^RTM 104PG50 manufactured by Nissin Chemical Co., Ltd. Preparation of an ink using the compound obtained in Example 1 is referred to as Example 3.
In addition, each test ink was prepared in the same manner as in Example 3 except that the dye obtained in Example 2 was used instead of the dye obtained in Example 1. This ink is referred to as Example 4.

[Comparative Example 1]
A comparative ink was prepared in the same manner as in Example 3 except that the dye described in International Publication No. 2012/081640 (Example 3) was used instead of the compound of the present invention obtained in Example 1. This ink preparation is referred to as Comparative Example 1. The structural formula of the compound used in Comparative Example 1 is shown in the following formula (26).

[(C) Inkjet recording]
Each of the inks prepared in Examples 3 to 4 and Comparative Example 1 was subjected to inkjet recording on the following two types of glossy paper using an inkjet printer (trade name: PIXUS ^RTM ip 7230, manufactured by Canon Inc.). . At the time of recording, an image pattern was prepared so that six gradation levels of 100%, 85%, 70%, 55%, 40%, and 25% density were obtained, and a halftone recorded matter was obtained. Using the obtained recorded matter as a test piece, the following test was conducted.

Glossy paper: manufactured by Fuji Film Co., Ltd., product name: Painting Photo Finishing Pro Super Glossy

[(D) Color measurement of recorded image]
Various tests and the evaluation thereof were performed by measuring the color of a test piece using a colorimeter manufactured by X-rite and a trade name of SpectroEye. Colorimetry was performed under the conditions of ANSI A as a density standard, a viewing angle of 2 degrees, and a light source D50.
The recorded image test method and test result evaluation method are described below.

[(D) Ozone resistance test]
The test piece was allowed to stand for 24 hours at an ozone concentration of 10 ppm, a bath temperature of 23 ° C., and a humidity of 50% RH using an ozone weather meter (model OMS-H manufactured by Suga Test Instruments Co., Ltd.). After the test, using the color measurement system, the print density (Dc) before and after the test was measured to determine the dye residual ratio. Since the black dye is considered to be decomposed more than the cyan component (Dc) on the long wavelength side, the dye remaining ratio of the cyan component (Dc) is more excellent when the numerical value is higher. The results are shown in Table 6 below. The dye residual ratio was calculated by the following formula. In the ozone resistance test, the print density (Dc) of the recorded matter before the test was measured, and the dye residual ratio at a gradation part of 55% was obtained. The evaluation criteria are as follows.

Dye remaining rate is 92% or more ...
Dye residual ratio is 90% or more and less than 92%.
Dye remaining rate is less than 90% ...

Dye remaining rate = (print density after test / print density before test) × 100 (%)

  As shown in Table 6, in the ozone resistance test of the printed matter, Examples 3 to 4 showed better results than Comparative Example 1 on glossy paper.

  From the above, it can be seen that the water-soluble azo compound of the present invention and the ink composition of the present invention containing the compound have higher ozone resistance of the printed matter than conventional dyes.

The azo compound of the present invention and the ink composition containing the azo compound are suitably used for black ink for various recordings such as writing utensils, particularly ink jet recording.

Claims (11)

An azo compound represented by the following formula (1), a tautomer thereof, or a salt thereof.

[In Formula (1),
R ¹ represents a (C1-C4) alkyl group; or a (C1-C4) alkyl group substituted with a carboxy group;
R ² represents a cyano group;
R ³ and R ⁴ each independently represent a hydrogen atom; a (C1-C4) alkoxy group; or a sulfo group;
R ⁵ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁶ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁷ represents a sulfo (C1-C4) alkoxy group,
R ⁸ represents a carboxy (C2-C4) alkylcarbonylamino group; or a 2-carboxyphenylcarbonylamino group; a (C1-C4) alkylsulfonylamino group; or a 4-methylphenylsulfonylamino group,
R ⁹ is a (C1-C4) alkylcarbonylamino group,
R ¹⁰ represents a methyl group;
R ^{11 to} R ¹³ each independently represent a hydrogen atom; a carboxy group; a sulfo group; a hydroxy group; an acetylamino group; a halogen atom; a cyano group; a nitro group; a sulfamoyl group; (C1 to C4) an alkyl group; (C4) alkoxy group; (C1-C4) alkoxy group substituted with at least one group selected from the group consisting of hydroxy group, (C1-C4) alkoxy group, sulfo group and carboxy group; (C1-C4) An alkylsulfonyl group; or a (C1-C4) alkylsulfonyl group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group. It is. ] In the above formula (1),
R ¹ represents a (C1-C4) alkyl group; or a (C1-C4) alkyl group substituted with a carboxy group;
R ² represents a cyano group,
R ³ and R ⁴ each independently represent a hydrogen atom; a (C1-C4) alkoxy group; or a sulfo group;
R ⁵ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁶ represents a (C1-C4) alkylthio group substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group and a carboxy group,
R ⁷ represents a sulfo (C1-C4) alkoxy group,
R ⁸ represents a carboxy (C2-C4) alkylcarbonylamino group; or a 2-carboxyphenylcarbonylamino group,
R ⁹ is a (C1-C4) alkylcarbonylamino group,
R ¹⁰ represents a methyl group;
R ^{11 to} R ¹³ represent a hydrogen atom; a sulfo group; or a nitro group;
The azo compound according to claim 1, or a tautomer thereof, or a salt thereof, wherein at least one of R ^{11 to} R ¹³ is a nitro group. In the above formula (1),
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfo (C1-C4) alkoxy group;
R ⁸ is a carboxy (C 2 -C 4) alkylcarbonylamino group;
R ⁹ is a (C1-C4) alkylcarbonylamino group;
R ¹⁰ is a methyl group;
The azo compound or a tautomer thereof according to claim 1 or 2, wherein at least one of R ^{11 to} R ¹³ is a nitro group, and the other two are each independently a sulfo group or a hydrogen atom, or their salt. In the above formula (1),
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a methoxy group;
R ⁴ is a sulfo group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a sulfo (C1-C4) alkylthio group;
R ⁷ is a sulfo (C1-C4) alkoxy group;
R ⁸ is a carboxyethylcarbonylamino group;
R ⁹ is a (C1-C4) alkylcarbonylamino group;
R ¹⁰ is a methyl group;
The azo compound according to any one of claims 1 to 3, or a tautomer thereof, or a salt thereof, wherein R ^{11 to} R ¹³ are a nitro group, a sulfo group, or a hydrogen atom.   An aqueous ink composition comprising at least one kind of the azo compound according to any one of claims 1 to 4 or a tautomer thereof, or a salt thereof as a coloring matter.   The water-based ink composition according to claim 5, further comprising a water-soluble organic solvent.   An ink jet recording method for recording on a recording material by using the ink composition according to claim 5 or 6 as ink and discharging ink droplets of the ink according to a recording signal.   The ink jet recording method according to claim 7, wherein the recording material is an information transmission sheet.   9. The ink jet recording method according to claim 8, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance.   An ink jet printer loaded with a container containing the ink composition according to claim 5. a) an azo compound according to any one of claims 1 to 4 or a tautomer thereof, or a salt thereof; or b) a colored body colored by the aqueous ink composition according to claim 5 or 6. .