JP2016176000A - Azo compound, ink composition, recording method and colored material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye which has extremely excellent ozone gas resistance, extremely high print density, excellent color rendering property, and a high-quality black hue with low saturation, and to provide an ink composition containing the dye.SOLUTION: The present invention provides an azo compound represented by formula (1) or a tautomer thereof, or a salt thereof [Ris a (C1-C4) alkyl group or the like; Ris a cyano group or the like; Rand Rindependently represent H, a carboxy group and the like (one of them is a carboxy group); Rand Rindependently represent a (C1-C4) alkylthio group or the like; Rand Rindependently represent a (C1-C4) alkylcarbonyl amino group; Ris a sulfo (C1-C4) alkoxy group; Ris a methyl group or the like; R-Rindependently represent H, a sulfo group or the like).SELECTED DRAWING: None

Description

  The present invention relates to a novel azo compound, a tautomer thereof, 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. In addition, due to the feature of being easy to downsize 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. With these inks, it is possible to provide a recording image with sufficient density, no clogging of the pen tip and nozzles, good drying on the recording material, less bleeding, and storage stability. It is required to be excellent. In addition, the water-soluble dye used is required to have a particularly high solubility in water and a high solubility in a 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 paper or in the recording paper to discolor the recorded image. . 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 and processing, it is common to use a compound having absorption at a long wavelength as a method for improving color rendering.

  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 safety and environmental issues for living organisms, and have extremely high gas resistance. There are problems such as weakness.

  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

  The present invention is particularly excellent in bronzing property when recorded on ink jet paper, excellent in (ozone) gas resistance, light resistance and moisture resistance, very high print density, excellent color rendering, and saturation. The purpose of the present invention is to provide a pigment having a low and 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；又は、カルボキシ基；を表し、
Ｒ²はシアノ基；カルバモイル基；又は、カルボキシ基；を表し、
Ｒ³及びＲ⁴は、それぞれ独立して、水素原子；（Ｃ１〜Ｃ４）アルキル基；ハロゲン原子；（Ｃ１〜Ｃ４）アルコキシ基；又は、カルボキシ基；を表し（ただし、Ｒ^３、Ｒ^４のいずれか一方は必ずカルボキシ基である）、
Ｒ⁵は、（Ｃ１〜Ｃ４）アルキルチオ基；又は、ヒドロキシ基、スルホ基及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、（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基を表し、
Ｒ⁷は、（Ｃ１〜Ｃ４）アルキルチオ基；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）アルキルチオ基；を表し、
Ｒ⁸は、（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基；を表し、
Ｒ⁹及びＲ¹⁰は、それぞれ独立して、水素原子；カルボキシ基；スルホ基；アセチルアミノ基；塩素原子；（Ｃ１〜Ｃ４）アルキル基；（Ｃ１〜Ｃ４）アルコキシ基；又は、ヒドロキシ基、（Ｃ１〜Ｃ４）アルコキシ基、スルホ基、及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；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；塩素原子；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、及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；アルキルスルホニル基；又は、ヒドロキシ基、スルホ基、及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。］
２）
下記式（２）で表されるアゾ化合物若しくはその互変異性体、又はそれらの塩、

［式（２）中、
Ｒ¹からＲ¹³は、式（１）におけるものと同じ意味を表す。]
３）
上記式（１）または（２）において、Ｒ^１１からＲ^１３の少なくとも１つがカルボキシ基で；Ｒ^５からＲ^１０の少なくとも１つがスルホ基またはカルボキシ基で置換された（Ｃ１〜Ｃ４）アルキルチオ基；又はスルホ（Ｃ１〜Ｃ４）アルコキシ基；である、上記１）または２）に記載のアゾ化合物もしくはその互変異性体、またはそれらの塩、
４）
上記式（１）又は（２）において、Ｒ^５及びＲ^７がスルホ基またはカルボキシ基で置換された（Ｃ１〜Ｃ４）アルキルチオ基；であり、Ｒ^９がスルホ（Ｃ１〜Ｃ４）アルコキシ基；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もしくはその互変異性体、またはそれらの塩、
５）
上記式（１）又は（２）において、Ｒ^１がメチル基；又はフェニル基；であり、Ｒ^２がシアノ基；又はカルバモイル基；であり、Ｒ^３が水素原子；であり、Ｒ^４がカルボキシ基；である、上記１）乃至４）のいずれか一項に記載のアゾ化合物もしくはその互変異性体、またはその塩、
６）
上記式（１）又は（２）において、
Ｒ¹がメチル基；、
Ｒ²がシアノ基；又はカルバモイル基；
Ｒ³が水素原子；、
Ｒ⁴がカルボキシ基；、
Ｒ⁵がスルホ基又はカルボキシ基で置換された（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁶が（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基；、
Ｒ⁷がスルホ基又はカルボキシ基で置換された（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁸が（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基；、
Ｒ⁹がスルホ（Ｃ１〜Ｃ４）アルコキシ基；、
Ｒ¹⁰が（Ｃ１〜Ｃ４）アルキル基；又はアセチルアミノ基；、
Ｒ¹¹からＲ¹³が、それぞれ独立して、水素原子；カルボキシ基；スルホ基；塩素原子；ニトロ基；メチル基；メトキシ基；スルファモイル基；又は、スルホ基もしくはカルボキシ基で置換された（Ｃ１〜Ｃ４）アルキルスルホニル基；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、
７）
式（１）又は（２）において、
Ｒ¹がメチル基；、
Ｒ²がシアノ基またはカルバモイル基；；、
Ｒ³が水素原子；、
Ｒ⁴がカルボキシ基；、
Ｒ⁵がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁶が（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基；、
Ｒ⁷がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁸が（Ｃ１〜Ｃ４）アルキルカルボニルアミノ基；、
Ｒ⁹がスルホ（Ｃ１〜Ｃ４）アルコキシ基；、
Ｒ¹⁰が（Ｃ１〜Ｃ４）アルキル基；またはアセチルアミノ基；塩素原子、
Ｒ¹¹からＲ¹³がそれぞれ独立して、水素原子；カルボキシ基；スルホ基；塩素原子；ニトロ基；メチル基；メトキシ基；スルファモイル基；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、
８）
式（１）又は（２）において、
Ｒ¹がメチル基；、
Ｒ²がシアノ基；；、
Ｒ³が水素原子；、
Ｒ⁴がカルボキシ基；、
Ｒ⁵がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁶がアセチルアミノ基；、
Ｒ⁷がスルホ（Ｃ１〜Ｃ４）アルキルチオ基；、
Ｒ⁸がアセチルアミノ基；、
Ｒ⁹がスルホプロポキシ基；、
Ｒ¹⁰が（Ｃ１〜Ｃ４）アルキル基；
Ｒ¹¹からＲ¹³がそれぞれ独立して、水素原子；スルホ基；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、
９）
上記１）乃至８）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、
１０）
水溶性有機溶剤をさらに含有する上記９）に記載の水性インク組成物、
１１）
上記９）又は１０）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、
１２）
被記録材が情報伝達用シートである上記１１）に記載のインクジェット記録方法、
１３）
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１２）に記載のインクジェット記録方法、
１４）
上記９）又は１０）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、
１５）
ａ）上記１）乃至８）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、
ｂ）上記９）又は１０）に記載の水性インク組成物、又は、
ｃ）上記１１）に記載のインクジェット記録方法、の３者のいずれか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; or a carboxy group;
R ² represents a cyano group; a carbamoyl group; or a carboxy group;
R ³ and R ⁴ each independently represents a hydrogen atom; a (C1-C4) alkyl group; a halogen atom; a (C1-C4) alkoxy group; or a carboxy group (provided that R ³ and R ⁴ are Any one is always a carboxy group),
R ⁵ represents a (C1-C4) alkylthio group; or 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) alkylcarbonylamino group,
R ⁷ represents a (C1-C4) alkylthio group; or 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 ⁸ represents a (C1-C4) alkylcarbonylamino group;
R ⁹ and R ¹⁰ are each independently a hydrogen atom; a carboxy group; a sulfo group; an acetylamino group; a chlorine atom; a (C1-C4) alkyl group; a (C1-C4) alkoxy group; or a hydroxy group, C1-C4) represents a (C1-C4) alkoxy group substituted with at least one group selected from the group consisting of an alkoxy group, a sulfo group, and a carboxy 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 chlorine atom; a cyano group; a nitro group; a sulfamoyl group; (C1-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; 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. ]
2)
An azo compound represented by the following formula (2) or a tautomer thereof, or a salt thereof;

[In Formula (2),
R ¹ to R ¹³ represent the same meaning as in formula (1). ]
3)
In the above formula (1) or (2), at least one of R ¹¹ to R ¹³ is a carboxy group; (C1-C4) alkylthio group in which at least one of R ⁵ to R ¹⁰ is substituted with a sulfo group or a carboxy group; Or a sulfo (C1-C4) alkoxy group; the azo compound according to 1) or 2) or a tautomer thereof, or a salt thereof,
4)
In the above formula (1) or (2), R ⁵ and R ⁷ are (C1 to C4) alkylthio groups substituted with a sulfo group or a carboxy group; and R ⁹ is a sulfo (C1 to C4) alkoxy group; The azo compound according to any one of 1) to 3) or a tautomer thereof, or a salt thereof,
5)
In the above formula (1) or (2), R ¹ is a methyl group; or a phenyl group; R ² is a cyano group; or a carbamoyl group; R ³ is a hydrogen atom; and R ⁴ is a carboxy group. The azo compound according to any one of 1) to 4) above, or a tautomer thereof, or a salt thereof,
6)
In the above formula (1) or (2),
R ¹ is a methyl group;
R ² is a cyano group; or a carbamoyl group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is substituted by a sulfo group or a carboxy group (C1 -C4) alkylthio groups;,
R ⁶ is a (C1-C4) alkylcarbonylamino group;
R ⁷ is substituted by a sulfo group or a carboxy group (C1 -C4) alkylthio groups;,
R ⁸ is a (C1-C4) alkylcarbonylamino group;
R ⁹ is a sulfo (C1-C4) alkoxy group;
R ¹⁰ is a (C1-C4) alkyl group; or an acetylamino group;
R ¹¹ to R ¹³ are each independently substituted with a hydrogen atom; a carboxy group; a sulfo group; a chlorine atom; a nitro group; a methyl group; a methoxy group; a sulfamoyl group; C4) an alkylsulfonyl group; the azo compound according to 1) or 2) or a tautomer thereof, or a salt thereof,
7)
In formula (1) or (2),
R ¹ is a methyl group;
R ² is a cyano group or a carbamoyl group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a (C1-C4) alkylcarbonylamino group;
R ⁷ is a sulfo (C1-C4) alkylthio group;
R ⁸ is a (C1-C4) alkylcarbonylamino group;
R ⁹ is a sulfo (C1-C4) alkoxy group;
R ¹⁰ is a (C1-C4) alkyl group; or an acetylamino group; a chlorine atom,
R ¹¹ to R ¹³ are each independently a hydrogen atom; a carboxy group; a sulfo group; a chlorine atom; a nitro group; a methyl group; a methoxy group; a sulfamoyl group; Its tautomers, or salts thereof,
8)
In formula (1) or (2),
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is an acetylamino group;
R ⁷ is a sulfo (C1-C4) alkylthio group;
R ⁸ is an acetylamino group;
R ⁹ is a sulfopropoxy group;
R ¹⁰ is a (C1-C4) alkyl group;
R ¹¹ to R ¹³ are each independently a hydrogen atom; a sulfo group; the azo compound according to 1) or 2) above or a tautomer thereof, or a salt thereof,
9)
An aqueous ink composition containing at least one kind of the azo compound according to any one of 1) to 8) or a tautomer thereof, or a salt thereof;
10)
The water-based ink composition as described in 9) above, further containing a water-soluble organic solvent,
11)
An ink jet recording method for recording on a recording material by using the ink composition according to 9) or 10) as an ink, and discharging ink droplets of the ink according to a recording signal;
12)
The inkjet recording method according to 11) above, wherein the recording material is an information transmission sheet,
13)
The inkjet recording method according to 12) above, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance,
14)
An inkjet printer loaded with a container containing the ink composition according to 9) or 10) above,
15)
a) The azo compound according to any one of 1) to 8) or a tautomer thereof, or a salt thereof,
b) The water-based ink composition as described in 9) or 10) above, or
c) A colored body colored by any one of the three methods described in 11) above.

  The azo compound or a salt thereof of the present invention and an ink composition containing the azo compound are suitably used as an ink for ink jet recording, and when recorded on ink jet dedicated paper, have a very high print density and excellent color rendering. In addition, the ink composition containing the azo compound of the present invention is extremely useful as a black ink for ink-jet recording because it has a low-saturation, high-quality black hue, and particularly excellent (ozone) gas resistance. is there.

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 (3) and (4). In formulas (3) and (4), 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, a linear group such as a methyl group, an ethyl group, an n-propyl group, and an n-butyl group; a branched chain such as an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group; Is mentioned. 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 in which any carbon atom of the unsubstituted (C1 to C4) alkyl group is substituted with a carboxy 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.

In the above formula (1), R ² represents a cyano group; a carbamoyl group; or a carboxy group. Among these, a cyano group and a carbamoyl group are preferable, and a cyano group is more preferable.

In the above formula (1), R ³ and R ⁴ each independently represent a hydrogen atom; a (C1-C4) alkyl group; a halogen atom; a (C1-C4) alkoxy group; or a carboxy group. Represent. However, one of R ³ and R ⁴ is necessarily a carboxy group.

Examples of the (C1 to C4) alkyl group in R ³ and R ⁴ include the same groups as those described above including the (C1 to C4) alkyl group in R ¹ and preferable ones.

Examples of the halogen atom in R ³ and R ⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferable.

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 a straight chain such as a methoxy group, an ethoxy group, an n-propoxy group, and an n-butoxy group; a branched chain such as an isopropoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group; Can be mentioned. In these, a methoxy group is more preferable.

A preferred combination of R ³ and R ^{4 is} a combination of one of a hydrogen atom and the other of a carboxy 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 carboxy 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 formula (1), R ¹ is a (C1 to C4) alkyl group (preferably a methyl group or an n-propyl group, more preferably a methyl group), and R ² is a cyano group. , R ³ is a hydrogen atom, and R ⁴ is a combination of carboxy groups.

In the above formula (1), R ⁶ and R ⁸ are each independently substituted with (C1-C4) alkylthio group; or substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group (C1-C4) represents an alkylthio group.

In the above formula (1), examples of the (C1 to C4) alkylthio group in R ⁵ and R ⁷ include those in which the alkyl moiety is linear or branched, and linear is preferable. Specific examples include straight chain such as methylthio, ethylthio, n-propylthio, n-butylthio; branched chain such as の propylthio, isobutylthio, sec-butylthio, tert-butylthio;

As the substituent in R ⁵ and R ^7, the (C1 to 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 to 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 hydroxy (C1-C4) alkylthio groups such as 2-hydroxyethylthio group, 2-hydroxypropylthio group, 3-hydroxypropylthio group; 2-sulfoethylthio group, 3-sulfopropylthio group. Sulfo (C1-C4) alkylthio groups such as a group; carboxy (C1-C4) alkylthio groups such as 2-carboxyethylthio group, 3-carboxypropylthio group, 4-carboxybutylthio group; and the like.

Among the above, preferable R ⁵ and R ⁷ 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. More preferred is a thio group.

In said formula (1), R < ⁶ > and R < ⁸ > represents a (C1-C4) alkylcarbonylamino group each independently.

In the above formula (1), examples of the (C1-C4) alkylcarbonylamino group in R ⁶ and R ⁸ include those in which alkyl is linear or branched, and linear is preferable. Specific examples thereof include straight chain such as acetylamino group (methylcarbonylamino group), propionylamino group (ethylcarbonylamino group), n-propylcarbonylamino group, n-butylcarbonylamino group; isopropylcarbonylamino And branched chain groups such as an isobutylcarbonylamino group, a sec-butylcarbonylamino group, and a pivaloylamino group (tert-butylcarbonylamino group). Of these, a straight chain is preferable, and an acetylamino group is more preferable.

A preferred combination of R ⁵ and R ^{6 is} a combination of R ⁵ is a sulfo (C1-C4) alkylthio group, R ⁶ is an acetylamino group, R ⁵ is a 3-sulfopropylthio group, and R ⁶ is an acetylamino group. A combination is more preferred. The same applies to R ⁷ and R ⁸ .

In the above formula (1), R ⁹ and R ¹⁰ are each independently a hydrogen atom; a carboxy group; a sulfo group; an acetylamino group; a chlorine atom; a (C1-C4) alkyl group; and a (C1-C4) alkoxy group. Or a (C1-C4) alkoxy group substituted with at least one group selected from the group consisting of a hydroxy group, a (C1-C4) alkoxy group, a sulfo group, and a carboxy 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 chlorine atom; a cyano group; a nitro group; a sulfamoyl group; (C1-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; 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.

In the above formula (1), examples of the (C1 to C4) alkyl group in R ⁹ and R ¹⁰ include the same as the (C1 to C4) alkyl group in R ¹ and preferable ones.

Examples of the (C1 to C4) alkoxy group in R ⁹ and R ¹⁰ include the same groups as the (C1 to C4) alkoxy group in R ³ and R ⁴ , including preferable ones.

As the (C1-C4) alkoxy group substituted with at least one group selected from the group consisting of a hydroxy group, a (C1-C4) alkoxy group, a sulfo group, and a carboxy group in R ⁹ and R ¹⁰ , What has these substituents is mentioned to the arbitrary carbon atoms in a (C1-C4) alkoxy group. 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 include hydroxy (C1-C4) alkoxy groups such as 2-hydroxyethoxy, 2-hydroxypropoxy and 3-hydroxypropoxy; sulfo (C1-C4) such as 2-sulfoethoxy, 3-sulfopropoxy and 4-sulfobutoxy. C4) alkoxy groups; carboxy (C1-C4) alkoxy groups such as 2-carboethoxy, 3-carbopropoxy, 4-carbobutoxy; and the like.

Among the above, preferable R ⁹ includes a sulfo (C1 to C4) alkoxy group and a carbo (C1 to C4) alkoxy group, more preferably a sulfo (C1 to C4) alkoxy group, a sulfopropoxy group and a sulfobutoxy group. Is particularly preferred.

Among the above, preferable R ¹⁰ includes (C1 to C4) alkyl group, (C1 to C4) alkoxy group, sulfo (C1 to C4) alkoxy group, carboxy (C1 to C4) alkoxy group, and acetylamino group. , A (C1-C4) alkyl group is more preferred, and a methyl group is particularly preferred.

A preferred combination of R ⁹ and R ^{10 is} a combination in which R ⁹ is a sulfo (C1-C4) alkoxy group, R ¹⁰ is a (C1-C4) alkyl group, and R ⁹ is a sulfopropoxy group (particularly a 3-sulfopropoxy group). And a combination of R ^{10 and} methyl group is particularly preferable.

In the above formula (1), examples of the (C1 to C4) alkyl group in R ¹¹ to R ¹³ include the same as the (C1 to C4) alkyl group in R ¹ and preferable ones.

In the above formula (1), the (C1-C4) alkoxy group in R ¹¹ to R ¹³ includes the same ones as the (C1-C4) alkoxy group in R ³ and R ⁴ , including preferable ones. .

In the above formula (1), R ¹¹ to R ¹³ are 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 (C1 The C4) alkoxy group is substituted with at least one group selected from the group consisting of a hydroxy group, a (C1-C4) alkoxy group, a sulfo group, and a carboxy group in R ⁵ and R ⁶ above (C1 -C4) The same thing is included including an alkoxy group and a preferable thing.

In the above formula (1), examples of the (C1-C4) alkylsulfonyl group in 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.

In the above formula (1), as the (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 in R ¹¹ to R ¹³ , (C1-C4) The thing by which said group was substituted by the arbitrary carbon atom in an alkylsulfonyl group is mentioned, The number of this substituent is 1 or 2 normally, Preferably it is one. 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 these, preferable R ¹¹ 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 preferable, and a sulfo group is 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, a carboxy group as an electron-withdrawing substituent, 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 preferable, and a sulfo group, a nitro group, a methyl group, a methoxy group, a sulfamoyl group, a sulfopropylsulfonyl group, a carboxy group, or the like. An ethylsulfonyl group and a chlorine atom are more preferable, and chlorine An atom and a sulfo group are particularly preferable. Most preferred is a sulfo group.

Among the above, preferable R ¹³ includes a hydrogen atom, a carboxy group, a sulfo group, a nitro group, a chlorine atom, a methyl group, a methoxy group, a (C1 to C4) alkylsulfonyl group, and the like. More preferred are a carboxy group, a sulfo group, a nitro group, a chlorine atom, a (C1 to C4) alkylsulfonyl group, or a methyl group or a methoxy group, more preferably a hydrogen atom and a chlorine atom, most preferably hydrogen. Atoms are particularly preferred.

A preferred combination of R ¹¹ to R ¹³ is particularly preferably a combination of R ¹¹ and R ¹² as a sulfo group and R ¹³ as a hydrogen atom.

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 the 1st position, R ¹¹ is the 2nd or 3rd position, R ¹² is the 4th position, and R ¹³ is the 5th position. Alternatively, those substituted at the 6-position are preferred, and more preferred are those wherein R ¹¹ is substituted at the 2-position, R ¹² is substituted at the 4-position, and R ¹³ is substituted at the 5-position or 6-position.
Particularly preferred in the formula (2) is the one in which the substitution positions of R ^{5 to} R ¹³ are specified as described above, and the types of substituents may be the same as those in the formula (1).

Specific examples of preferable combinations in the formulas (1) to (3) 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; or a carbamoyl group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is substituted by a sulfo group or a carboxy group (C1 -C4) alkylthio groups;,
R ⁶ is a (C1-C4) alkylcarbonylamino group;
R ⁷ is substituted by a sulfo group or a carboxy group (C1 -C4) alkylthio groups;,
R ⁸ is a (C1-C4) alkylcarbonylamino group;
R ⁹ is a sulfo (C1-C4) alkoxy group;
R ¹⁰ is a (C1-C4) alkyl group; or an acetylamino group;
R ¹¹ to R ¹³ are each independently substituted with a hydrogen atom; a carboxy group; a sulfo group; a chlorine atom; a nitro group; a methyl group; a methoxy group; a sulfamoyl group; or a sulfo group or a carboxy group (C1 to C4). A combination of alkylsulfonyl groups;
(Ii)
R ¹ is a methyl group;
R ² is a cyano group; or a carbamoyl group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a (C1-C4) alkylcarbonylamino group;
R ⁷ is a sulfo (C1-C4) alkylthio group;
R ⁸ is a (C1-C4) alkylcarbonylamino group;
R ⁹ is a sulfo (C1-C4) alkoxy group;
R ¹⁰ is a (C1-C4) alkyl group; or an acetylamino group;
A combination in which R ¹¹ to R ¹³ are each independently a hydrogen atom; a carboxy group; a sulfo group; a chlorine atom; a nitro group; a methyl group; a methoxy group; or a sulfamoyl group.
(Iii)
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is an acetylamino group;
R ⁷ is a sulfo (C1-C4) alkylthio group;
R ⁸ is an acetylamino group;
R ⁹ is a sulfo (C1-C4) alkoxy group;
R ¹⁰ is a (C1-C4) alkyl group;
R ¹¹ is a sulfo group;
R ¹² is a sulfo group;
A combination in which R ¹³ is a hydrogen atom;
(Iv)
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is an acetylamino group;
R ⁷ is a sulfo (C1-C4) alkylthio group;
R ⁸ is an acetylamino group;
R ⁹ is a sulfopropoxy group;
R ¹⁰ is a methyl group;
R ¹¹ is a sulfo group;
R ¹² is a sulfo group;
A combination in which R ¹³ is a hydrogen atom;

  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.

A more preferred compound of the above formula (1) is a compound represented by the above formula (2). In formula (2), R ¹ to R ¹³ represent the same meaning as in formula (1).

The tetrakisazo compound of the present invention represented by the 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 (5) to (12), R ^{1 to} R ¹³ represent the same meaning as in the above formula (1).
A compound represented by the following formula (5) is diazotized by a conventional method, and the obtained diazo compound and a compound represented by the following formula (6) are subjected to a coupling reaction by a conventional method, and represented by the following formula (7). To obtain the compound.

  The obtained compound of the above formula (7) is diazotized by a conventional method, and then the obtained diazo compound and a compound represented by the following formula (8) are subjected to a coupling reaction by a conventional method to obtain the following formula (9) To obtain a compound represented by:

  The obtained compound of the above formula (9) is diazotized by a conventional method, and then the obtained diazo compound and a compound represented by the following formula (10) are subjected to a coupling reaction by a conventional method to obtain the following formula (11) To obtain a compound represented by:

  The obtained compound of the above formula (11) is diazotized by a conventional method, and then the obtained diazo compound and a compound represented by the following formula (12) are subjected to a coupling reaction by a conventional method, whereby the above formula ( The azo compound of the present invention represented by 1) can be obtained.

  The compound represented by the above formula (12) can be synthesized according to the method described in Patent Document 3.

Although it does not specifically limit as a suitable specific example of the azo compound of this invention represented by Formula (1), The compound etc. which are shown by the structural formula given to the following Tables 1 thru | or 4 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 of formula (5) is carried out in a manner known per se, for example a nitrite, for example nitrous acid, in an inorganic acid medium, for example at a temperature of −5 to 30 ° C., preferably 0 to 15 ° C. This is done using an alkali metal nitrite such as sodium. Coupling of the diazotized compound of the compound of formula (5) with the compound of formula (6) is also carried out under conditions known per se. 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 of formula (5) and the compound of formula (6) are used in approximately stoichiometric amounts.

  The diazotization of the compound represented by the above formula (7) is carried out by a method known per se, for example, a nitrite such as nitrous acid 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 nitrate. Coupling of the diazotized compound of the compound of formula (7) with the compound of formula (8) is also carried out under conditions known per se. It is advantageous to carry out 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 of formula (7) and the compound of formula (8) are used in approximately stoichiometric amounts.

  The diazotization of the compound represented by the above formula (9) 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 of formula (9) with the compound of formula (10) is also carried out under conditions known per se. It is advantageous to carry out in water or an aqueous organic medium, for example at a temperature of -5 to 50 [deg.] C, preferably 10 to 40 [deg.] C and 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 of formula (9) and the compound of formula (10) are used in approximately stoichiometric amounts.

  The diazotization of the compound represented by the above formula (11) is also carried out by a method known per se, for example, a nitrite such as nitrous acid in an inorganic acid medium at a temperature of, for example, -5 to 50 ° C, preferably 10 to 40 ° C. This is done using an alkali metal nitrite such as sodium. Coupling of the diazotized compound of the compound of formula (11) and the compound of formula (12) is also carried out under conditions known per se. 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 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 compounds of formulas (11) and (12) are used in approximately stoichiometric amounts.

  The salt of the azo compound represented by the above formula (1) is a salt with an inorganic or organic cation. Among these, specific examples of inorganic salts include alkali metal salts, alkaline earth metal salts, and ammonium salts. Preferred inorganic salts are lithium, sodium, potassium, and ammonium salts. Examples of the organic cation salt include, but are not limited to, salts with quaternary ammonium ions represented by the following formula (13). 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. The physical properties such as solubility may vary depending on the type of salt, and the physical properties that meet the purpose can be selected by selecting the type of salt as appropriate, or by changing the ratio when multiple salts are included. It is also possible to obtain a mixture having

In the above formula (13), Z ¹ , Z ² , Z ³ and Z ⁴ each independently represent a group selected from the group consisting of a hydrogen atom, an unsubstituted alkyl group, a hydroxyalkyl group and a hydroxyalkoxyalkyl group, At least one is a group other than a hydrogen atom.
Specific examples of the alkyl group represented by Z ^{1 to} Z ⁴ in the formula (13) include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and the like. Specific examples include hydroxy (C1-C4) alkyl groups such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl, and the like. Examples of alkyl groups include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl and the like. Ci (C1-C4) alkoxy (C1-C4) alkyl groups may be mentioned, and among these, hydroxyethoxy (C1-C4) alkyl is preferred. Particularly preferred are hydrogen atoms; hydroxy (C1-C4) alkyl groups such as methyl, hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl, etc. Hydroxyethoxy (C1-C4) alkyl such as hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl Groups.

Specific examples of combinations of Z ¹ , Z ² , Z ³ , and Z ^{4 which} are preferable compounds as the formula (13) are shown in Table 5 below.

As a method for synthesizing a desired salt of the azo compound represented by the formula (1) of the present invention, after completion of the final step in the synthesis reaction of the compound represented by the formula (1), a desired inorganic salt or organic Obtained by 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 or an aqueous organic medium as necessary to remove impurities such as attached inorganic salts, and again in an 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 refers to 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 organic cation salts include halogen salts of quaternary ammonium ions represented by the above formula (13) such as diethanolamine hydrochloride and triethanolamine hydrochloride.

  The ink composition of the present invention will be described. The azo compound represented by the formula (1) of the present invention can dye a material made of cellulose by forming an aqueous composition containing the compound. In addition, materials having a carbonamide bond can be dyed, and 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; A product 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 formula (1) of the present invention as a pigment. It is a water-based ink composition containing. 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 containing a small amount 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; or a dried product or wet cake of the azo compound of the present invention with an alcohol such as methanol, preferably (C1-C4) alcohol In addition, the mixture may be suspended and purified in a mixed solvent of water and water, and the precipitate may be desalted by a known method such as a method of separating and drying the precipitate by filtration.

Specific examples of water-soluble organic solvents that can be used in preparing the ink composition of the present invention include (C1-C4) alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol or tert-butanol. A carboxylic acid amide such as N, N-dimethylformamide or N, N-dimethylacetamide; a lactam such as 2-pyrrolidone, hydroxyethyl-2-pyrrolidone, N-methyl-2-pyrrolidone or N-methylpyrrolidin-2-one Cyclic cyclic ureas such as 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido-2-one; acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one, etc. Ketones or ketoalcohols; tetrahydrofuran, dioxa Cyclic ethers such as 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, Mono-, oligo- or polyalkylene glycols or thioglycols having C2-C6 alkylene units such as tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol or dithiodiglycol; trimethylolpropane, glycerin or hexane-1 , 2,6-triol and other polyols (preferably triol); ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol (C1-C4) alkyl ethers of polyhydric alcohols such as dimethyl monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol) triethylene glycol monomethyl ether or triethylene glycol monoethyl ether; γ-butyrolactone; or dimethyl Sulfoxide; and the like. 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, and benzothiazole. , Isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, benzyl Examples thereof include bromoacetate-based or inorganic salt-based compounds. Specific examples of organic halogen compounds include sodium pentachlorophenol, specific examples of pyridine oxide compounds include, for example, sodium 2-pyridinethiol-1-oxide, and isothiazoline compounds include, 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 -Isothiazoline-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 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); Or alkali metal carbonates, such as lithium carbonate, sodium carbonate, sodium hydrogencarbonate, potassium carbonate; Alkali metal salts of organic acids, such as potassium acetate; Inorganic bases, such as sodium silicate and disodium phosphate, etc. are mentioned.

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

  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 dissolving agent 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 or heterocyclic rings. .

Examples of the surfactant include known surfactants such as anionic, cationic, and nonionic surfactants.
Examples of anionic surfactants include alkyl sulfonates, alkyl carboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurate, alkyl sulfate poly Oxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl sulfonate, diethyl Examples include sulfosuccinate, 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, or imidazoline derivatives. 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 they 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; or a porous white inorganic substance capable of absorbing a pigment in the ink, such as porous silica, alumina sol, or special ceramics. And a hydrophilic polymer such as polyvinyl pyrrolidone, and the like.
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 inkjet recording method of the present invention comprises the black ink composition of the present invention and, for example, the known magenta, cyan, yellow, and green, blue (or violet), red (or orange), etc. as necessary. 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 8) or a tautomer thereof, or a salt thereof,
b) The water-based ink composition as described in 9) or 10) above, or
c) A substance colored by any one of the three methods of the ink jet recording method described in 11) 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.
An image recorded with the ink composition of the present invention has a particularly excellent bronzing property, a high printing density, a low color rendering property, a low saturation, and a high-quality black hue. Excellent fastness such as ozone gas resistance, 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.
Operations such as each synthesis reaction and crystallization 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)
41.8 parts of 4-chloro-3-nitroaniline was dissolved in 60.0 parts of N-methyl-2-pyrrolidone, and 35.2 parts of acetic anhydride was added dropwise thereto in about 15 minutes. After the dropwise addition, the reaction solution was added to 400 parts of water after reacting at 40-50 ° C. for 2 hours. After stirring at room temperature for 30 minutes, the precipitated solid was filtered, and the obtained solid was washed with 100 parts of funnel water, separated and dried to obtain 63.0 parts of a compound represented by the following formula (14). Obtained.

(Process 2)
42.9 parts of the compound represented by the formula (14) obtained in Example 1 (Step 1) was dissolved in 115.0 parts of N-methyl-2-pyrrolidone, and sodium 3-mercaptopropanesulfonate was dissolved therein. 40.9 parts and 29.0 parts of potassium carbonate were added. After the addition, the mixture was heated to 130 to 140 ° C. and reacted at the same temperature for 2 hours. After further adding 3.6 parts of sodium 3-mercaptopropanesulfonate, the mixture was reacted at 130 to 140 ° C. for 1 hour. After cooling to 60 ° C., the reaction solution was added to 700 parts of 2-propanol, and the solid obtained after cooling to room temperature was collected by filtration. The obtained wet cake was dissolved in 300 parts of water, adjusted to pH 3.0 to 4.0 by adding 35% hydrochloric acid, salted out with sodium chloride, and the precipitated solid was collected by filtration, and the following formula (15 ) Was obtained as a wet cake.

(Process 3)
In 150 parts of water, 102.6 parts of a wet cake of the compound represented by the formula (15) obtained in Example 1 (Step 2), 1.6 parts of activated carbon and 0.4 parts of anhydrous iron chloride (III) After heating to 60 ° C., 15.9 parts of 80% hydrazine hydrate was added dropwise over about 30 minutes. After heating to 90 ° C., the reaction was carried out at the same temperature for 1.5 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 addition of 50% sulfuric acid, and the precipitated solid was collected by filtration to obtain 62.3 parts of a compound represented by the following formula (16) as a wet cake.

(Process 4)
After adding 5.1 parts of aniline-2,4-disulfonic acid represented by the following formula (17) to 50 parts of water, an aqueous solution was obtained at pH 4.0 to 5.0 by adding a 25% aqueous sodium hydroxide solution. . After adding 6.3 parts of 35% hydrochloric acid, 4.2 parts of 40% aqueous sodium nitrite solution was added and reacted 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, after adding 9.5 parts of a wet cake of the compound represented by the formula (16) obtained in Example 1 (Step 3) to 100 parts of water, pH 4. An aqueous solution was obtained as 0 to 5.0. This aqueous solution was added dropwise to the diazo reaction solution obtained above in about 5 minutes. After dropping, the reaction was continued for 3 hours while maintaining the pH at 2.0 to 4.0 by adding a 15% aqueous sodium carbonate solution, then sodium chloride was added to adjust the pH to 0.8 to 1.0 with 35% hydrochloric acid. did. The precipitated solid was collected by filtration to obtain 24.8 parts of a wet cake containing a compound represented by the following formula (18).

(Process 5)
After adding the entire amount of the wet cake of the compound represented by the formula (18) 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 5.63 parts of 35% hydrochloric acid, 3.8 parts of 40% aqueous sodium nitrite solution was added and reacted 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, after adding 8.6 parts of a wet cake of the compound represented by the formula (16) obtained in Example 1 (step 3) to 100 parts of water, pH 4. An aqueous solution was obtained as 0 to 5.0. This aqueous solution was added dropwise to the diazo reaction solution obtained above in about 5 minutes. After the dropwise addition, the reaction was continued for 3 hours while maintaining the pH at 2.0 to 2.5 by adding 15% aqueous sodium carbonate solution, then sodium chloride was added, and the acid was adjusted to pH 0.8 to 1.0 by adding 35% hydrochloric acid. Salted out. The precipitated solid was collected by filtration to obtain 33.2 parts of a wet cake containing a compound represented by the following formula (19).

(Step 6)
33.2 parts of a wet cake of the compound represented by the formula (19) obtained in Example 1 (Step 5) above was added to 100 parts of water and dissolved by stirring. After adding 4.7 parts of 35% hydrochloric acid, 3.2 parts of 40% aqueous sodium nitrite solution was added and stirred for about 30 minutes. 0.4 part of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid.
On the other hand, 3.9 parts of a 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 to 7.0 is added by adding a 25% aqueous sodium hydroxide solution. As an aqueous solution was obtained. This aqueous solution was added dropwise to the diazo reaction solution obtained above in about 5 minutes. After dripping, it reacted for 3 hours, maintaining pH at 3.0-4.5 by addition of 15% sodium carbonate aqueous solution. After the pH was adjusted to 8.0 to 8.5 by adding a 25% aqueous sodium hydroxide solution, sodium chloride was added. The precipitated solid was collected by filtration to obtain 55.4 parts of a wet cake containing a compound represented by the following formula (21).

(Step 7)
To a mixed solution of 40 parts of isopropyl alcohol and 30 parts of methanol, 5.0 parts of methyl 3,4-diaminobenzoate and 9.8 parts of a compound represented by the following formula (22) are added and refluxed for 2 hours. By returning and separating the precipitated solid by filtration, 71.4 parts of a solution (filtrate) containing a compound represented by the following formula (23) was obtained.

(Process 8)
71.4 parts of a solution (filtrate) containing the compound represented by (23) obtained in Example 1 (Step 7) above in 100 parts of ethanol, 8.1 parts of 28% sodium methoxide, and methyl acetoacetate After adding 4.9 parts and refluxing for 2 hours, 35% hydrochloric acid was added to make an acidic solution, and the precipitated solid was separated by filtration and dried to obtain 33.2 parts of a compound represented by the following formula (24). Obtained.

(Step 9)
After adding 20.4 parts of the compound represented by (24) obtained in Example 1 (Step 8) to 200 parts of 5% aqueous sodium hydroxide solution, the mixture was stirred at room temperature for 12 hours. 80 g of sodium chloride was added to the reaction solution to obtain 26.7 parts of a wet cake of a compound represented by the following formula (25). The obtained wet cake was dissolved in 100 parts of water, 300 parts of isopropyl alcohol was added, and the precipitated solid was collected by filtration. The obtained wet cake is dissolved again in 50 parts of water, 200 parts of isopropyl alcohol is added, the precipitated solid is separated by filtration, and dried to obtain 3.5 parts of a compound represented by the following formula (25). It was.

(Process 10)
To 80 parts of water, 6.3 parts of the compound represented by the formula (21) obtained in Example 1 (Step 6) was added and dissolved by stirring. After adding 2.9 parts of 35% hydrochloric acid, 1.0 part of 40% aqueous sodium nitrite was added and stirred for about 30 minutes. 1.2 parts of sulfamic acid was added here, and it stirred for 5 minutes, and obtained the diazo reaction liquid.
On the other hand, 1.9 parts of the compound represented by the formula (25) obtained in Example 1 (Step 9) above was added to 80 parts of water, and a 25% aqueous sodium hydroxide solution was added to adjust the pH to 7.5-8. 5 to obtain an aqueous solution. The diazo reaction liquid obtained above was added dropwise to this aqueous solution at 0 to 10 ° C. for about 30 minutes. At this time, an 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 12 hours while maintaining the same temperature and pH adjustment. The obtained reaction liquid was dropped into 400 parts of methanol, and the precipitated solid was separated by filtration to obtain a wet cake. The obtained wet cake was dissolved in 150 parts of water, adjusted to pH 7.0 to 7.5 with 35% hydrochloric acid, then dropped into 200 parts of methanol isopropyl alcohol and 200 parts of methanol, and the precipitated solid was collected by filtration. did. The wet cake was dried to obtain a compound represented by the following formula (26) of the present invention as a black powder as a 6.3 part sodium salt.
λmax: 596 nm.

[Example 2]
[(B) Ink adjustment]
The dye obtained in Example 1 was mixed with the components shown in Table 6 below to obtain a black ink composition of the present invention, and then impurities were filtered off with a 0.45 μm membrane filter. The obtained ink was designated as Example 2. The obtained ink composition is hereinafter referred to as “ink”.
Moreover, ion-exchange water was used for water. At the time of ink adjustment, the pH of the ink was adjusted to pH 7-9 with sodium hydroxide, and then ion exchange water was added to make the total amount 100 parts. In addition, as a surfactant in Table 6 below, Nissin Chemical Co., Ltd., trade name Surfynol 104PG50 was used.

[Comparative Example 1]
A comparative ink was prepared in the same manner as in Example 4 except that the pigment of the following formula (27) was used as the black pigment for comparison. The following various tests conducted using this ink are referred to as Comparative Example 1. In addition, the compound of the following formula (27) is the compound (38) described in Example 9 in International Publication No. 2012/081640, and was obtained by following the methods described in the literature.

[(C) Inkjet recording]
The respective ink compositions obtained in Example 2 and Comparative Example 1 were used, and ink jet recording was performed on the following printing paper using an ink jet printer (trade name: Canon iP7230).

Glossy Paper 1: Product Name Canon Photo Paper / Glossy Pro PT-101A42
Glossy paper 2: Glossy paper manufactured by Seiko Epson Corporation, trade name Photographic paper Krispia ^RTM

At the time of printing, as a test piece for hue evaluation, an image pattern is made so that six gradations of reflection densities of 100%, 85%, 70%, 55%, 40%, and 25% are obtained, and dark black A light black gradation recorded matter was obtained, and this was used as a test piece, and the following evaluation test was performed. Since the gray scale mode is used at the time of printing, yellow, magenta and cyan recording liquids other than black recording are not used together.

[(D) Evaluation of recorded image]
Each recorded image obtained using the ink of Example 2 was evaluated by measuring the density change of the image before and after the test. The change in density of the recorded image was measured using a colorimeter manufactured by GRETAG-MACBETH, trade name: SpectroEye. When measuring colors, all were performed under the conditions of ANSI A, viewing angle of 2 °, and light source D50 based on the density standard.
The specific test method is as follows.

[(E) Ozone property test]
Each recorded image obtained using the ink of Example 2 and Comparative Example 1 was naturally dried for 24 hours after printing, and the ozone concentration was measured using an ozone weatherometer manufactured by Suga Test Instruments Co., Ltd. Each test piece was allowed to stand for 24 hours under the conditions of 10 ppm, humidity 60% RH, and temperature 24 ° C. After completion of the test, the colorimetry was performed using the above colorimeter, and the dye residual ratio was determined by (reflected density Dk after test / reflected density Dk before test) × 100 (%) and evaluated according to the following criteria. . As the evaluation obtained, a high residual ratio indicates that there is little discoloration due to ozone and is excellent.
The results are shown in Table 7 below.

◎ Residual rate: 96% or more ○ Residual rate: 94% or more and less than 96% △ Residual rate: 92% or more and less than 94% × Residual rate: Less than 92%

  As is clear from the results in Table 7, it was revealed that the ink of each Example 2 was extremely excellent in ozone resistance as compared with the ink of Comparative Example 1. It was also found that even if the paper was different, it was not the same color. That is, it is clear that the residual ratio of the Dk concentration after the ozone resistance test is high, and the fading against ozone is improved. It is also clear that high-quality recorded images can be obtained with media without a significant decrease in fastness.

  From the above, it can be seen that the ink composition using the compound of Example 1 is better than Comparative Example 1 in ozone resistance.

  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 (15)

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; or a carboxy group;
R ² represents a cyano group; a carbamoyl group; or a carboxy group;
R ³ and R ⁴ each independently represents a hydrogen atom; a (C1-C4) alkyl group; a halogen atom; a (C1-C4) alkoxy group; or a carboxy group (provided that R ³ and R ⁴ are Any one is always a carboxy group),
R ⁵ represents a (C1-C4) alkylthio group; or 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) alkylcarbonylamino group,
R ⁷ represents a (C1-C4) alkylthio group; or 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 ⁸ represents a (C1-C4) alkylcarbonylamino group;
R ⁹ and R ¹⁰ are each independently a hydrogen atom; a carboxy group; a sulfo group; an acetylamino group; a chlorine atom; a (C1-C4) alkyl group; a (C1-C4) alkoxy group; or a hydroxy group, C1-C4) represents a (C1-C4) alkoxy group substituted with at least one group selected from the group consisting of an alkoxy group, a sulfo group, and a carboxy 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 chlorine atom; a cyano group; a nitro group; a sulfamoyl group; (C1-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; 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. ] An azo compound represented by the following formula (2), a tautomer thereof, or a salt thereof.

[In Formula (2),
R ¹ to R ¹³ represent the same meaning as in formula (1). ] In the formula (1) or (2), at least one of R ¹¹ to R ¹³ is a carboxy group; at least one of R ⁵ to R ¹⁰ is a (C1-C4) alkylthio group substituted with a sulfo group or a carboxy group; Or an azo compound or a tautomer thereof, or a salt thereof according to claim 1 or 2, which is a sulfo (C1-C4) alkoxy group. In the formula (1) or (2), R ⁵ and R ⁷ are (C1 to C4) alkylthio groups substituted with a sulfo group or a carboxy group; and R ⁹ is a sulfo (C1 to C4) alkoxy group; The azo compound or tautomer thereof according to any one of claims 1 to 3, or a salt thereof. In the formula (1) or (2), R ¹ is a methyl group; or a phenyl group; R ² is a cyano group; or a carbamoyl group; R ³ is a hydrogen atom; and R ⁴ is a carboxy group. The azo compound according to any one of claims 1 to 4 or a tautomer thereof, or a salt thereof. In the formula (1) or (2),
R ¹ is a methyl group;
R ² is a cyano group; or a carbamoyl group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is substituted by a sulfo group or a carboxy group (C1 -C4) alkylthio groups;,
R ⁶ is a (C1-C4) alkylcarbonylamino group;
R ⁷ is substituted by a sulfo group or a carboxy group (C1 -C4) alkylthio groups;,
R ⁸ is a (C1-C4) alkylcarbonylamino group;
R ⁹ is a sulfo (C1-C4) alkoxy group;
R ¹⁰ is a (C1-C4) alkyl group; or an acetylamino group;
R ¹¹ to R ¹³ are each independently substituted with a hydrogen atom; a carboxy group; a sulfo group; a chlorine atom; a nitro group; a methyl group; a methoxy group; a sulfamoyl group; The azo compound according to claim 1 or 2, or a tautomer thereof, or a salt thereof. In formula (1) or (2),
R ¹ is a methyl group;
R ² is a cyano group or a carbamoyl group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is a (C1-C4) alkylcarbonylamino group;
R ⁷ is a sulfo (C1-C4) alkylthio group;
R ⁸ is a (C1-C4) alkylcarbonylamino group;
R ⁹ is a sulfo (C1-C4) alkoxy group;
R ¹⁰ is a (C1-C4) alkyl group; or an acetylamino group; a chlorine atom,
The azo compound according to claim 1 or 2, wherein R ¹¹ to R ¹³ are each independently a hydrogen atom; a carboxy group; a sulfo group; a chlorine atom; a nitro group; a methyl group; a methoxy group; Tautomers or salts thereof. In formula (1) or (2),
R ¹ is a methyl group;
R ² is a cyano group;
R ³ is a hydrogen atom;
R ⁴ is a carboxy group;
R ⁵ is a sulfo (C1-C4) alkylthio group;
R ⁶ is an acetylamino group;
R ⁷ is a sulfo (C1-C4) alkylthio group;
R ⁸ is an acetylamino group;
R ⁹ is a sulfopropoxy group;
R ¹⁰ is a (C1-C4) alkyl group;
The azo compound according to claim 1 or 2, or a tautomer thereof, or a salt thereof, wherein R ¹¹ to R ¹³ are each independently a hydrogen atom; a sulfo group. A water-based ink composition comprising at least one kind of the azo compound according to any one of claims 1 to 8, a tautomer thereof, or a salt thereof as a pigment. The water-based ink composition according to claim 9, further comprising a water-soluble organic solvent. An ink jet recording method for performing recording on a recording material by using the ink composition according to claim 9 or 10 as ink and discharging ink droplets of the ink in accordance with a recording signal. The inkjet recording method according to claim 11, wherein the recording material is an information transmission sheet. 13. The ink jet recording method according to claim 12, 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 9. a) The azo compound according to any one of claims 1 to 8, or a tautomer thereof, or a salt thereof,
b) The aqueous ink composition according to claim 9 or 10, or
c) A colored body colored by any one of the three methods of the ink jet recording method according to claim 11.