JP2009298896A - Water-soluble azo compound, ink composition and colored article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment having a hue of a color from yellow, orange, brown to red, excellent color developing property, excellent fastness in various properties such as light resistance, ozone gas resistance and moisture resistance for inkjet recording or writing utensils, and excellent solubility with water, and a pigment also having good storage stability, and to provide an ink composition containing the pigment. <P>SOLUTION: A water-soluble azo compound expressed by formula (1) or a salt of the compound is disclosed. In formula (1), each of R<SP>1</SP>and R<SP>2</SP>independently represents a hydrogen atom, an non-substituted 1-4C alkyl group, or the like; group A represents a residue of a monoazo compound, or the like; and group B represents a substituted aliphatic amino group or the like. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel water-soluble azo compound or a salt thereof, an ink composition containing the same, and a colored body colored with the compound.

  A recording method using an ink jet printer, which is one of representative methods among various color recording methods, generates ink droplets and attaches them to various recording materials (paper, film, fabric, etc.) for recording. Is. This method has been spreading rapidly in recent years due to the fact that the recording head and the recording material are not in direct contact, so there is little noise and quietness, and it is easy to reduce the size and speed. Expected. Conventionally, water-based inks in which water-soluble pigments are dissolved in water-based media have been used as inks for fountain pens, felt-tip pens, and the like and inks for inkjet recording. In these water-based inks, a water-soluble organic solvent is generally added 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, ozone gas resistance, and moisture resistance.

The above-mentioned ozone gas resistance is resistance to a phenomenon in which an ozone gas having an oxidizing action existing in the air acts on a dye in a recording paper and discolors a printed 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 and fading phenomenon of ink jet recorded images.
Many ink-receiving layers provided on the surface of photographic image-dedicated inkjet paper use a material such as a porous white inorganic material in order to expedite ink drying and reduce bleeding at high image quality. Discoloration due to ozone gas is noticeable on such recording paper. Since the discoloration and discoloration phenomenon caused by this oxidizing gas, particularly ozone gas, is characteristic of ink jet images, the improvement of ozone gas resistance is one of the most important issues in the ink jet recording method.

  In the future, in order to expand the field of use in printing methods using ink, the ink composition used for ink jet recording and the colored body colored thereby will have various light resistance, ozone gas resistance, moisture resistance, water resistance, etc. There is a strong demand for further improvements in robustness.

Although inks of various hues are prepared from various pigments, black ink is an important ink used not only for printing character information but also for color images. However, it is technically difficult to develop a pigment that exhibits a good black color with a neutral hue in both the dark color gamut and light color gamut, a high color density, and a small hue dependency on the light source. R & D has been carried out, but there are still few that have sufficient performance. Therefore, generally, a black ink is prepared by mixing a plurality of various pigments.
In particular, in order to constitute a high-quality black to gray achromatic color, a coloring matter (dye) having a hue such as yellow to orange to brown to red is required for toning.
As a black ink containing a triazine dye and a black dye, for example, an aqueous black ink composition disclosed in Patent Document 1 is known, and a compound represented by the following formula (3) is proposed as the triazine dye. Has been.
Patent Document 2 proposes a dye represented by the following formula (4) and an ink composition containing the same as a dye for yellow-orange-brown-red ink excellent in ozone gas resistance. .

  With the widespread use of inkjet recording methods, their uses are expanding. Up to now, four colors of ink, yellow, magenta, cyan, or black, have been used, but it is also possible to use multicolored inks such as red, green, blue and orange. It is being considered. The use of multicolor ink is one of the purposes to faithfully reproduce all colors in the natural world by ink jet recording. To meet this demand, various dyes capable of reproducing natural colors in terms of hue, saturation, print density, etc., which are more delicate than conventional dyes of various colors such as yellow, orange, brown and red. And inks containing the same.

JP 2002-332426 A WO2006 / 001274

  The present invention has high solubility in a medium containing water as a main component, is stable even when a high-concentration dye aqueous solution and ink are stored for a long period of time, has a high printed image density, does not cause bronzing, and is printed. It provides a recorded image with excellent image fastness, especially ozone gas resistance and light resistance, and is suitable for composing an achromatic black to gray color by blending with a black dye, and easy to synthesize An object of the present invention is to provide a yellow-orange-brown-red ink coloring matter and an ink composition containing the coloring matter.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific water-soluble azo compound represented by the following formula (1) or a salt thereof can solve the above problems. And the present invention has been completed.

That is, the present invention
1)
Water-soluble azo compound represented by the following formula (1) or a salt thereof

[In Formula (1),
R ¹ and R ² are each independently a hydrogen atom; a chlorine atom; a hydroxy group; a sulfo group; a carboxy group; a sulfamoyl group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted group, a hydroxy group, or an unsubstituted C1 group. A C1-C4 alkoxy group substituted with a -C4 alkoxy group, a hydroxy C1-C4 alkoxy group or a carboxy group; a mono- or di-C1-C4 alkylamino group which is unsubstituted or substituted with a hydroxy group, a sulfo group or a carboxy group An unsubstituted or C1-C4 alkylcarbonylamino group substituted with a hydroxy group or a carboxy group; an N'-C1-C4 alkylureido group unsubstituted or substituted with a hydroxy group, a sulfo group or a carboxy group; Unsubstituted or benzene ring is chlorine atom, unsubstituted C1-C4 alkyl group, nitro group, sulfo group Is a phenylamino group substituted with a carboxy group; unsubstituted or a benzoylamino group in which the benzene ring is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group or a carboxy group; or unsubstituted Or a phenylsulfonylamino group in which the benzene ring is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group, or a carboxy group;
Group A is a substituted or unsubstituted aliphatic amino group; a substituted or unsubstituted aromatic amino group; a substituted or unsubstituted phenoxy group; or a residue of a monoazo compound,
The group B represents a substituted or unsubstituted aliphatic amino group; a substituted or unsubstituted aromatic amino group; or a hydroxy group, respectively. ],
2)
The water-soluble group according to 1), wherein the group A is a residue of a monoazo compound, and the group B is an aliphatic amino group having a carboxy group or a sulfo group; an aromatic amino group having a carboxy group or a sulfo group; or a hydroxy group Azo compounds or salts thereof,
3)
The water-soluble azo compound or a salt thereof according to 1) above, wherein the group A is a residue of a monoazo compound and the group B is an aliphatic amino group having a carboxy group or a sulfo group,
4)
A water-soluble azo compound represented by the following formula (2) or a salt thereof,

[In Formula (2),
n is an integer from 1 to 3,
x is an integer from 1 to 3,
R ³ and R ⁴ are each independently a hydrogen atom; a chlorine atom; a hydroxy group; a sulfo group; an unsubstituted C1-C4 alkyl group; an unsubstituted or hydroxy group, an unsubstituted C1-C4 alkoxy group, a hydroxy C1-C4 C1-C4 alkoxy group substituted with an alkoxy group or a sulfo group; unsubstituted or mono- or di-C1-C4 alkylamino group substituted with a hydroxy group or a sulfo group; C1 substituted with an unsubstituted or hydroxy group -C4 alkylcarbonylamino group; N'-C1-C4 alkylureido group unsubstituted or substituted with a hydroxy group or a sulfo group; unsubstituted or a benzene ring is a chlorine atom, an unsubstituted C1-C4 alkyl group, A phenylamino group substituted by a nitro group or a sulfo group; unsubstituted or a benzene ring is a chlorine atom, an unsubstituted C1-C4 alkyl group, Benzoylamino group substituted with b group or a sulfo group; unsubstituted or substituted benzene ring is a chlorine atom, an unsubstituted C1-C4 alkyl group, phenyl sulfonylamino group substituted with a nitro group or a sulfo group; a,
The ring substituted by — (SO ₃ H) n represents a benzene ring when a ring represented by a broken line is not present; and a naphthalene ring when a ring represented by a broken line is present. ],
5)
In equation (2),
i)
There is no ring represented by a broken line,
R ³ and R ⁴ are each independently a hydrogen atom; a sulfo group; an unsubstituted or sulfo-substituted C1-C4 alkoxy group;
n is an integer of 1 or
ii)
There is a ring represented by a broken line,
R ³ and R ⁴ are each independently a hydrogen atom; a sulfo group; an unsubstituted C1-C4 alkyl group; an unsubstituted C1-C4 alkylcarbonylamino group; an unsubstituted or sulfo-substituted C1-C4 alkoxy group;
n is an integer of 2 or 3,
The water-soluble azo compound or a salt thereof according to 4) above,
6)
There is no ring represented by a broken line,
One of R ³ and R ⁴ is a hydrogen atom, the other is a sulfo group,
the water-soluble azo compound or a salt thereof according to 4) or 5) above, wherein n is an integer of 1 and x is an integer of 2,
7)
An ink composition comprising at least one water-soluble azo compound or salt thereof according to any one of 1) to 6) as a pigment;
8)
An ink jet recording method for performing recording by using the ink composition described in 7) as an ink, and ejecting ink droplets of the ink in accordance with an ejection signal and attaching the ink droplet to a recording material;
9)
The inkjet recording method according to 8) above, wherein the recording material is an information transmission sheet,
10)
The inkjet recording method according to 9) above, wherein the information transmission sheet is a sheet containing a porous white inorganic substance,
11)
An inkjet printer loaded with a container containing the ink composition described in 7) above;
12)
A colored body colored with the water-soluble azo compound or salt thereof according to any one of 1) to 6) above;
About.

Since the water-soluble azo compound represented by the above formula (1) or a salt thereof of the present invention is excellent in water solubility, the filterability by a membrane filter in the process of producing an ink composition is good, and ink jet recording. Excellent discharge stability at the time. Further, the ink composition of the present invention containing the azo compound or a salt thereof has good storage stability without solid precipitation, physical property change, color change and the like after long-term storage. The ink composition of the present invention contains at least one water-soluble azo compound of the present invention or a salt thereof as a coloring matter. The ink composition is suitably used for inkjet recording and writing instruments. When recording on plain paper and inkjet dedicated paper, the recording density of the recorded image is high and no bronzing occurs even on glossy paper used for photographic recording. Furthermore, it is excellent in various fastnesses, such as water resistance, light resistance, and moisture resistance, especially ozone gas resistance.
The water-soluble azo compound of the present invention or a salt thereof is used as a dye for obtaining a wide hue from yellow to orange to brown to red, or as a dye for adjusting a color tone difference other than black with a subtle texture. It is also useful as a pigment for constituting an achromatic black to gray by blending with a black pigment and toning. Therefore, the ink composition of the present invention containing at least one of the compounds or salts thereof is extremely useful as an ink for inkjet recording.

The present invention will be described in detail. In the present specification, unless otherwise specified, acidic functional groups such as sulfo group and carboxy group are represented in the form of free acid.
In the following description, unless otherwise specified, the “water-soluble azo compound of the present invention” including both the “water-soluble azo compound of the present invention or a salt thereof” is simply described for convenience.
The water-soluble azo compound of the present invention is represented by the following formula (1).

In the above formula (1), R ¹ and R ² are each independently a hydrogen atom; a chlorine atom; a hydroxy group; a sulfo group; a carboxy group; a sulfamoyl group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; , A hydroxy group, an unsubstituted C1-C4 alkoxy group, a C1-C4 alkoxy group substituted with a hydroxy C1-C4 alkoxy group or a carboxy group; an unsubstituted or mono- or substituted with a hydroxy group, a sulfo group or a carboxy group Di-C1-C4 alkylamino group; unsubstituted or C1-C4 alkylcarbonylamino group substituted with a hydroxy group or a carboxy group; N'-unsubstituted or substituted with a hydroxy group, a sulfo group or a carboxy group C1-C4 alkylureido group; unsubstituted or a benzene ring is a chlorine atom, an unsubstituted C1-C4 alkyl group, A phenylamino group substituted with a rho group, a sulfo group or a carboxy group; unsubstituted or a benzoylamino group whose benzene ring is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group or a carboxy group Or a phenylsulfonylamino group in which the benzene ring is unsubstituted or substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group or a carboxy group;

The unsubstituted C1-C4 alkyl group for R ¹ and R ² may be either linear or branched, but is preferably linear. Specific examples of the C1-C4 alkyl group include straight chain such as methyl, ethyl, n-propyl and n-butyl; branched chain such as isopropyl, isobutyl, sec-butyl and t-butyl.

Examples of the unsubstituted C1-C4 alkoxy group in R ¹ and R ² include linear or branched ones. Specific examples include straight chain such as methoxy, ethoxy, n-propoxy and n-butoxy; branched chain such as isopropoxy, sec-butoxy and t-butoxy;
When the alkoxy group is substituted with a hydroxy group, an unsubstituted C1-C4 alkoxy group, a hydroxy C1-C4 alkoxy group, or a carboxy group, specific examples thereof include 2-hydroxyethoxy, 2-hydroxypropoxy, 3 Hydroxy C1-C4 alkoxy groups such as hydroxypropoxy; methoxyethoxy, ethoxyethoxy, n-propoxyethoxy, isopropoxyethoxy, n-butoxyethoxy, methoxypropoxy, ethoxypropoxy, n-propoxypropoxy, isopropoxybutoxy, n-propoxy Unsubstituted C1-C4 alkoxy C1-C4 alkoxy group such as butoxy; hydroxy C1-C4 alkoxy C1-C4 alkoxy group such as 2-hydroxyethoxyethoxy; carboxymethoxy, 2-carboxye Alkoxy, carboxy C1-C4 alkoxy group such as a 3-carboxypropoxy; and the like.

Examples of the unsubstituted mono- or di-C1-C4 alkylamino group in R ¹ and R ² include linear or branched ones. Specific examples thereof include linear amino acids such as methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, dimethylamino, diethylamino, di-n-propylamino, di-n-butylamino; branched chain such as sec-butylamino, t-butylamino, diisopropylamino; and the like.
When the mono- or di-C1-C4 alkylamino group is substituted with a hydroxy group, a sulfo group or a carboxy group, specific examples thereof include, for example, 2-hydroxyethylamino, 2-hydroxypropylamino, 2,2 ′. -Hydroxy-substituted mono or di-C1-C4 alkylamino group such as dihydroxydiethylamino; sulfo-substituted mono such as 2-sulfoethylamino, 3-sulfopropylamino, 4-sulfobutylamino, 3,3'-disulfodipropylamino Or di-C1-C4 alkylamino group; carboxy-substituted mono- or di-C1-C4 alkylamino group such as carboxymethylamino, 2-carboxyethylamino, 3-carboxypropylamino, 2,2′-dicarboxydiethylamino, etc. It is done.

Examples of the unsubstituted C1-C4 alkylcarbonylamino group in R ¹ and R ² include straight-chain or branched-chain groups, and straight-chain is preferable. Specific examples include acetylamino (methylcarbonylamino), propanoylamino, butanoylamino, pentanoylamino and the like.
When the C1-C4 alkylcarbonylamino group is substituted with a hydroxy group or a carboxy group, specific examples of the C1-C4 alkylcarbonylamino group include, for example, hydroxyethanoylamino, 2-hydroxypropanoylamino, 4 -Hydroxy C1-C4 alkylcarbonylamino group such as hydroxybutanoylamino; Carboxy C1-C4 alkylcarbonylamino group such as 3-carboxypropanoylamino; and the like.

As the N′-C1-C4 alkylureido group in R ¹ and R ² , those having a substituent are preferable rather than unsubstituted.
When the N′-C1-C4 alkylureido group is substituted with a hydroxy group, a sulfo group or a carboxy group, specific examples thereof include N′-2-hydroxyethylureido and N′-3-hydroxypropyl. N′-hydroxy C1-C4 alkylureido group such as ureido; N′-sulfoC1-C4 alkylureido group such as N′-2-sulfoethylureido, N′-3-sulfopropylureido; N′-carboxymethylureido N′-2-carboxyethylureido, N′-3-carboxypropylureido, N′-4-carboxybutylureido, and other N′-carboxyC1-C4 alkylureido groups;

In the above R ¹ and R ² , the substituent of the phenylamino group, benzoylamino group, or phenylsulfonylamino group having a substituent, the substituent of the benzene ring contained in each group is linear as the unsubstituted C1-C4 alkyl group. Examples include branched ones. Specific examples include, for example, linear ones such as methyl, ethyl, n-propyl and n-butyl; branched ones such as isopropyl, isobutyl, sec-butyl and t-butyl;

Specific examples of the phenylamino group in which the benzene ring in R ¹ and R ² is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group, or a carboxy group include, for example, 2-chlorophenylamino, 4- Chlorine atom-substituted phenylamino groups such as chlorophenylamino and 2,4-dichlorophenylamino; C1-C4 alkyl-substituted phenylamino groups such as 2-methylphenylamino, 4-methylphenylamino and 4-t-butylphenylamino; Nitro-substituted phenylamino groups such as nitrophenylamino and 4-nitrophenylamino; sulfo-substitutions such as 3-sulfophenylamino, 4-sulfophenylamino, 2,4-disulfophenylamino, and 3,5-disulfophenylamino Phenylamino group; 2-carboxyphenylamino, 4-carbo Carboxy-substituted phenylamino groups such as xylphenylamino, 2,5-dicarboxyphenylamino, 3,5-dicarboxyphenylamino; and the like.

Specific examples of the benzoylamino group in which the benzene ring in R ¹ and R ² is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group, or a carboxy group include, for example, 2-chlorobenzoylamino, 4 A chlorine atom-substituted benzoylamino group such as chlorobenzoylamino and 2,4-dichlorophenylamino; a C1-C4 alkyl-substituted benzoylamino group such as 2-methylbenzoylamino, 3-methylbenzoylamino and 4-methylbenzoylamino; Nitro-substituted benzoylamino groups such as nitrobenzoylamino, 4-nitrobenzoylamino and 3,5-dinitrobenzoylamino; sulfo-substituted benzoylamino groups such as 2-sulfobenzoylamino and 4-sulfobenzoylamino; 2-carboxybenzoylamino; 4-carboxy Carboxy-substituted benzoylamino groups such as benzoylamino and 3,5-dicarboxybenzoylamino; and the like.

Specific examples of the phenylsulfonylamino group in which R ¹ and R ² are substituted with a benzene ring by a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group, or a carboxy group include, for example, 2-chlorophenylsulfonylamino A chlorine atom-substituted phenylsulfonylamino group such as 4-chlorophenylsulfonylamino; a C1-C4 alkyl-substituted phenylsulfonylamino group such as 2-methylphenylsulfonylamino, 4-methylphenylsulfonylamino, 4-t-butylphenylsulfonylamino; Nitro-substituted phenylsulfonylamino groups such as 2-nitrophenylsulfonylamino, 3-nitrophenylsulfonylamino, 4-nitrophenylsulfonylamino, and the like; 3-sulfophenylsulfonylamino, 4-sulfophenylsulfonylamino, etc. A sulfo-substituted phenylsulfonylamino group; a carboxy-substituted phenylsulfonylamino group such as 3-carboxyphenylsulfonylamino, 4-carboxyphenylsulfonylamino; and the like.

Of these, R ¹ is preferably a hydrogen atom.

Among the above, preferable as R ² are a hydrogen atom; a sulfo group; an unsubstituted C1-C4 alkyl group; an unsubstituted or C1-C4 alkoxy group substituted with a hydroxy group or a hydroxy C1-C4 alkoxy group; a hydroxy group; A di-C1-C4 alkylamino group substituted with a sulfo group or a carboxy group; an unsubstituted or a C1-C4 alkylcarbonylamino group substituted with a hydroxy group or a carboxy group, more preferably an unsubstituted C1-C4 alkyl group It is a group.

Specific examples of preferable R ¹ and R ² in the formula (1) are a hydrogen atom; carboxy, sulfo, methyl, ethyl, methoxy, ethoxy, 2-hydroxyethoxy, carboxymethoxy, 2-carboxyethoxy, methylamino, ethylamino, 2-hydroxyethylamino, 2-sulfoethylamino, 3-sulfopropylamino, 2-carboxyethylamino, dimethylamino, diethylamino, 2,2′-dihydroxydiethylamino, 2,2′-dicarboxydiethylamino, 3,3 ′ -Disulfodipropylamino, acetylamino, 3-carboxypropanoylamino, 4-hydroxybutanoylamino, N'-carboxymethylureido, N'-2-sulfoethylureido, 4-sulfophenylamino, 2,4- Disulfophenylamino, 2,5-di Ruboxyphenylamino, benzoylamino, 3-sulfobenzoylamino, 2-carboxybenzoylamino, phenylsulfonylamino, 4-methylphenylsulfonylamino, 4-nitrophenylsulfonylamino, 3-sulfophenylsulfonylamino, 4-carboxyphenylsulfonyl Amino, etc., more preferably hydrogen atom, sulfo, methyl, methoxy, 2-hydroxyethoxy, 2-sulfoethoxy, 3-sulfopropoxy, 4-sulfobutoxy, dimethylamino, 3,3′-disulfodipropyl Amino, acetylamino, 3-carboxypropanoylamino, N′-2-sulfoethylureido, 2,4-disulfophenylamino, benzoylamino, 4-methylphenylsulfonylamino, more preferably water Elemental atom, sulfo, methyl and methoxy, particularly preferably hydrogen atom and methyl.

In the preferred combination of R ¹ and R ² in formula (1), R ¹ is methyl, methoxy, acetylamino or a hydrogen atom, R ² is a hydrogen atom, more preferably R ¹ is a hydrogen atom and R ² is methyl.

In the above formula (1), the group A is a substituted or unsubstituted aliphatic amino group; a substituted or unsubstituted aromatic amino group; a substituted or unsubstituted phenoxy group; or the residue of a monoazo compound, and the group B is substituted Or an unsubstituted aliphatic amino group; a substituted or unsubstituted aromatic amino group; or a hydroxy group, respectively.

The unsubstituted aliphatic amino group in the group A or B includes a linear or branched chain, preferably a linear mono or dialkylamino group. The alkyl group usually has C1-C8, preferably C1-C6, more preferably C1-C5, and in the case of dialkylamino, C1-C3 is more preferable. Specific examples of the monoalkylamino group include linear amino acids such as methylamino, ethylamino, n-propylamino, n-butylamino, n-pentylamino, n-hexylamino, n-heptylamino, and n-octylamino. Those having a branched chain such as isopropylamino, isobutylamino, t-butylamino, isopentylamino, isohexylamino, isoheptylamino, isooctylamino, and the like. Examples of dialkylamino include linear ones such as dimethylamino, diethylamino, and di-n-propylamino; branched ones such as diisopropylamino; straight chain such as isopropylmethylamino, ethylisopropylamino, and isopropyl (n-propyl) amino. A chain and a branched chain one by one;

The substituted aliphatic amino group in the group A or B is one in which the unsubstituted aliphatic amino group has a substituent. Although it does not restrict | limit especially as this substituent, The group etc. which are selected from the group which consists of sulfo, oxo, hydroxy, C1-C4 alkoxy, carboxy, etc. are mentioned preferably. The number of substituents is usually 1 to 3, preferably 2, and more preferably 1. Specific examples include sulfo-substituted monoalkylamino groups such as sulfomethylamino, sulfoethylamino, 2-sulfopropylamino, 3-sulfopropylamino, sulfo-n-butylamino, sulfo-n-pentylamino; bis- ( Sulfo-substituted dialkylamino groups such as sulfomethyl) amino, bis- (sulfoethyl) amino, bis- (sulfopropyl) amino; oxo-substituted monoalkylamino groups such as n-propionylamino, isopropionylamino; hydroxyacetylamino, 2-hydroxy Hydroxy and oxo substituted monoalkylamino groups such as -n-propionylamino, 3-hydroxy-n-propionylamino, 2-hydroxy-n-butyrylamino, 3-hydroxy-n-butyrylamino; 2-methoxy-n-propionylamino; C1-C4 alkoxy and oxo substituted monoalkylamino groups such as -methoxy-n-propionylamino, 2-methoxy-n-butyrylamino, 3-methoxy-n-butyrylamino; carboxymethylamino, carboxyethylamino, carboxypropylamino, carboxy A carboxy-substituted monoalkylamino group such as n-butylamino and carboxy-n-pentylamino; a carboxy-substituted dialkylamino such as bis- (carboxymethyl) amino, bis- (carboxyethyl) amino and bis- (carboxypropyl) amino Group; etc. are mentioned.

  In the group A or B, the unsubstituted aromatic amino group is preferably one having 6 to 10 carbon atoms, more preferably a phenylamino group or a naphthylamino group, still more preferably a phenylamino group. A group is one in which these groups have a substituent. Although it does not restrict | limit especially as a substituent of a substituted aromatic amino group, The group etc. which are selected from the group which consists of sulfo, carboxy, amino, and hydroxy are mentioned preferably. The number of substituents is usually 1 to 3, preferably 1 or 2. Specific examples of the substituted aromatic amino group include sulfo-substituted ones such as 2-, 3-, or 4-sulfophenylamino; 2-, 3-, or 4-carboxyphenylamino, 3,5-dicarboxyphenyl Carboxy substituted, such as amino; amino substituted, such as 3- or 4-aminophenylamino, 3,5-diaminophenylamino; hydroxy substituted, such as 2-, 3-, or 4-hydroxyphenylamino A group in which two groups selected from the above groups such as 2-carboxy-4-hydroxyphenylamino and 2-carboxy-4-sulfophenylamino are substituted; and the like.

  The substituent of the substituted phenoxy group in the group A or B is not particularly limited, but preferred is sulfo, carboxy, or hydroxy. The number of substituents is usually 1 to 3, preferably 1 or 2. Specific examples include sulfo-substituted ones such as 2-, 3-, or 4-sulfophenoxy; carboxy-substituted ones such as 2-, 3-, or 4-carboxyphenoxy, 3,5-dicarboxyphenoxy; 2 Hydroxy-substituted ones such as-, 3-, or 4-hydroxyphenoxy;

The residue of the monoazo compound in group A is not particularly limited as long as it is a compound having a monoazo structure, but has an amino group that has a substituent and is bonded to the triazine ring in the above formula (1). Monoazo compounds are preferred. Preferred examples of the “monoazo compound having an amino group” include naphthylazophenylamino group; or phenylazophenylamino group; the latter is more preferable.
Examples of the substituent of these groups include sulfo; unsubstituted or sulfo-substituted C1-C4 alkoxy group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C3 alkylcarbonylamino group; and a group selected from the group consisting of Preferably, sulfo is more preferable. In the case of a naphthylazophenylamino group, the number of the substituents is usually 1 to 5, preferably 1 to 4, and in the case of a phenylazophenylamino group, usually 1 to 3, preferably 1 or 2. Preferably it is 2.
Preferred examples of the residue of the monoazo compound include a residue obtained by removing one hydrogen atom from the amino group (—NH ₂ ) of the compound represented by the following formula (E). Specific examples include Examples thereof include residues represented by compound numbers 1-1 to 1-14 described in Table 1 and Table 2 described later.

Of the above, the group A is preferably a residue of a monoazo compound.
The group B is preferably a substituted aliphatic amino group, more preferably a substituted monoalkylamino group, and even more preferably a sulfo-substituted monoalkylamino group.

In the above formula (1), there are no particular restrictions on the substitution positions of the two sulfos whose substitution positions are not specified. The sulfo substituted with a benzene ring having one azo bond may be substituted at the 2, 3 or 4 position, preferably the 4 position, with the substitution position of the azo bond as the 1 position.
On the other hand, sulfo substituted with a benzene ring having two azo bonds is the 2-position or 3-position with the substitution position of the azo bond joining the benzene ring and the benzene ring substituted with R ¹ and R ² as the first position. It is preferable to substitute at the 2-position.

What is preferable as the water-soluble azo compound of the present invention represented by the above formula (1) is a compound represented by the following formula (2).

In formula (2), n represents an integer of 1 to 3. Preferably it is 1 or 2, more preferably 1.

In formula (2), x represents an integer of 1 to 3. Preferably it is 2.

In formula (2), R ³ and R ⁴ each independently represent a hydrogen atom; a chlorine atom; a hydroxy group; a sulfo group; an unsubstituted C1-C4 alkyl group; an unsubstituted or hydroxy group, an unsubstituted C1-C4 alkoxy group A C1-C4 alkoxy group substituted with a group, a hydroxy C1-C4 alkoxy group or a sulfo group; an unsubstituted or mono- or di-C1-C4 alkylamino group substituted with a hydroxy group or a sulfo group; an unsubstituted or hydroxy C1-C4 alkylcarbonylamino group substituted with a group; unsubstituted or N′-C1-C4 alkylureido group substituted with a hydroxy group or a sulfo group; unsubstituted or a benzene ring is a chlorine atom, unsubstituted A phenylamino group substituted with a C1-C4 alkyl group, a nitro group or a sulfo group; unsubstituted or a benzene ring is a chlorine atom, an unsubstituted C1-C4 atom; A benzoylamino group substituted with a kill group, a nitro group or a sulfo group; an unsubstituted or phenylsulfonylamino group in which the benzene ring is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group or a sulfo group; , Respectively.

The unsubstituted C1-C4 alkyl group for R ³ and R ⁴ may be the same as the unsubstituted C1-C4 alkyl group for R ¹ and R ^2, including preferred ones and specific examples.

The unsubstituted C1-C4 alkoxy group for R ³ and R ⁴ may be the same as the unsubstituted C1-C4 alkoxy group for R ¹ and R ^2, including preferred ones and specific examples.
The same applies to the case where the alkoxy group is substituted with a hydroxy group, an unsubstituted C1-C4 alkoxy group, a hydroxy C1-C4 alkoxy group, or a sulfo group.

The unsubstituted mono- or di-C1-C4 alkylamino group in R ³ and R ^{4 includes} the unsubstituted mono- or di-C1-C4 alkylamino group in R ¹ and R ^{2 as} well as preferred and specific examples. It can be the same.
The same applies to the case where the mono- or di-C1-C4 alkylamino group is substituted with a hydroxy group or a sulfo group.

The unsubstituted C1-C4 alkyl carbonyl amino group in the above R ³ and R ^4, and unsubstituted C1-C4 alkyl carbonyl amino group in the above R ¹ and R ^2, may be the same, including preferred and specific examples and the like.
The same applies to the case where the C1-C4 alkylcarbonylamino group is substituted with a hydroxy group.

The N′—C 1 -C 4 alkylureido group in R ³ and R ⁴ may be the same as the N′—C 1 -C 4 alkylureido group in R ¹ and R ^2, including preferred ones and specific examples.
The same applies to the case where the N′-C1-C4 alkylureido group is substituted with a hydroxy group or a sulfo group.

In the above R ³ and R ⁴ , a phenylamino group having a substituent, a benzoylamino group, or a phenylsulfonylamino group, the substituent of the benzene ring contained in each group is linear as an unsubstituted C1-C4 alkyl group, A branched chain or a cyclic | annular thing is mentioned, A linear or branched chain is preferable. Specific examples include, for example, linear ones such as methyl, ethyl, n-propyl and n-butyl; branched ones such as isopropyl, isobutyl, sec-butyl and t-butyl;

Specific examples of the phenylamino group in which the benzene ring in R ³ and R ⁴ is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, or a sulfo group include, for example, 2-chlorophenylamino, 4-chlorophenylamino Chlorine atom substituted phenylamino groups such as 2,4-dichlorophenylamino; C1-C4 alkyl substituted phenylamino groups such as 2-methylphenylamino, 4-methylphenylamino, 4-t-butylphenylamino; 2-nitrophenyl Nitro-substituted phenylamino groups such as amino and 4-nitrophenylamino; sulfo-substituted phenylamino groups such as 3-sulfophenylamino, 4-sulfophenylamino, 2,4-disulfophenylamino and 3,5-disulfophenylamino Group; etc. are mentioned.

Specific examples of the benzoylamino group in which the benzene ring in R ³ and R ⁴ is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group or a sulfo group include, for example, 2-chlorobenzoylamino, 4-chloro Chlorine atom-substituted benzoylamino groups such as benzoylamino and 2,4-dichlorophenylamino; C1-C4 alkyl-substituted benzoylamino groups such as 2-methylbenzoylamino, 3-methylbenzoylamino and 4-methylbenzoylamino; 2-nitrobenzoyl Nitro-substituted benzoylamino groups such as amino, 4-nitrobenzoylamino and 3,5-dinitrobenzoylamino; sulfo-substituted benzoylamino groups such as 2-sulfobenzoylamino and 4-sulfobenzoylamino; and the like.

Specific examples of the phenylsulfonylamino group in which the benzene ring in R ³ and R ⁴ is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group or a sulfo group include, for example, 2-chlorophenylsulfonylamino, 4- Chlorine atom substituted phenylsulfonylamino groups such as chlorophenylsulfonylamino; C1-C4 alkyl substituted phenylsulfonylamino groups such as 2-methylphenylsulfonylamino, 4-methylphenylsulfonylamino, 4-t-butylphenylsulfonylamino; 2-nitro Nitro-substituted phenylsulfonylamino groups such as phenylsulfonylamino, 3-nitrophenylsulfonylamino, 4-nitrophenylsulfonylamino; sulfo-substituted such as 3-sulfophenylsulfonylamino, 4-sulfophenylsulfonylamino Phenylsulfonylamino group; and the like.

Among the above, preferred as R ³ are a hydrogen atom; sulfo; an unsubstituted C1-C4 alkyl group; a C1-C4 alkoxy group unsubstituted or substituted with a sulfo group; and more preferably sulfo.
Preferred as R ⁴ are a hydrogen atom; an unsubstituted C1-C4 alkyl group; an unsubstituted C1-C4 alkylcarbonylamino group; and more preferably a hydrogen atom.

Preferred examples of R ³ and R ⁴ include a hydrogen atom, sulfo, methyl, ethyl, methoxy, ethoxy, 2-hydroxyethoxy, 2-sulfoethoxy, 3-sulfopropoxy, 4-sulfobutoxy, methylamino, and ethyl. Amino, 2-hydroxyethylamino, 2-sulfoethylamino, 3-sulfopropylamino, dimethylamino, diethylamino, 2,2′-dihydroxydiethylamino, 3,3′-disulfodipropylamino, acetylamino, 4-hydroxy Butanoylamino, N′-2-sulfoethylureido, 4-sulfophenylamino, 2,4-disulfophenylamino, benzoylamino, 3-sulfobenzoylamino, phenylsulfonylamino, 4-methylphenylsulfonylamino, 4- Nitrophenylsulfonylamino And 3-sulfophenylsulfonylamino, more preferably a hydrogen atom, sulfo, methyl, methoxy, 2-hydroxyethoxy, 2-sulfoethoxy, 3-sulfopropoxy, 4-sulfobutoxy, dimethylamino, 3, 3′-disulfodipropylamino, acetylamino, N′-2-sulfoethylureido, 2,4-disulfophenylamino, benzoylamino, 4-methylphenylsulfonylamino, more preferably hydrogen atom, sulfo , Methyl, methoxy, 3-sulfopropoxy and acetyl, particularly preferably a hydrogen atom and sulfo.

In the preferable combination of R ³ and R ⁴ in the formula (2), R ³ is a hydrogen atom, methoxy, sulfo or 3-sulfopropoxy, R ⁴ is a hydrogen atom, methyl or acetylamino, more preferably R ³ is In sulfo, R ⁴ is a hydrogen atom.

In the formula (2), the ring substituted by — (SO ₃ H) n is a benzene ring when a ring represented by a broken line is not present; a naphthalene ring when a ring represented by a broken line is present; To express.
When the ring represented by the broken line does not exist, that is, the ring substituted with — (SO ₃ H) n is preferably a benzene ring.

In formula (2), the preferred combination of the ring represented by the broken line and R ³ and R ⁴ varies depending on the presence or absence of the ring represented by the broken line. As the combination, the following two types i) or ii) are preferable, and i) is more preferable.
i) There is no ring represented by a broken line, and R ³ and R ⁴ are each independently a hydrogen atom; a sulfo group; an unsubstituted or sulfo-substituted C1-C4 alkoxy group; and n is an integer of 1 Some combination.
ii) a ring represented by a broken line is present, and R ³ and R ⁴ are each independently a hydrogen atom; a sulfo group; an unsubstituted C1-C4 alkyl group; an unsubstituted C1-C4 alkylcarbonylamino group; A sulfo-substituted C1-C4 alkoxy group; and a combination wherein n is an integer of 2 or 3.

R ^{1 to} R ⁴ , group A, group B, n, x, a ring represented by a broken line, and a sulfo substitution position where the substitution position is not specified are represented by the above formulas (1) and (2). In the description of the water-soluble azo compound of the present invention, compounds in which preferable ones are combined are more preferable, and those in which more preferable ones are combined are more preferable. The same applies to preferable ones.

  The compound represented by the above formula (1) exists also as a free acid or a salt thereof. Examples of the salt of the compound represented by the formula (1) include salts with inorganic or organic cations. Specific examples of the salt with an inorganic cation include alkali metal salts such as lithium, sodium, potassium and the like. Examples of the salt with an organic cation include a salt with a quaternary ammonium represented by the following formula (5), but are not limited thereto.

Wherein (5) represents a Z ¹ to Z ⁴ each independently represent a hydrogen atom, a C1-C4 alkyl group, hydroxy C1-C4 alkyl group or a hydroxy C1-C4 alkoxy C1-C4 alkyl group. ]

Here, examples of the C1-C4 alkyl group in Z ^{1 to} Z ⁴ include methyl, ethyl and the like, and examples of the hydroxy C1-C4 alkyl group include hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2- Examples thereof include hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl and the like, and examples of the hydroxy C1-C4 alkoxy C1-C4 alkyl group include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxybutyl, and the like. (Hydroxyethoxy) propyl, 3- (hydroxyethoxy) butyl, 2- (hydroxyethoxy) butyl and the like.

  Preferable examples of the salt include sodium, potassium, lithium, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine salt, and ammonium salt. Of these, particularly preferred are lithium, sodium, potassium and ammonium salts.

As will be apparent to those skilled in the art, the salt of the compound represented by the above formula (1) can be easily obtained by the following method.
For example, salt is added to the reaction solution in the final step in the synthesis reaction of the compound represented by the formula (1), a wet cake containing the compound, or an aqueous solution in which the compound is dissolved, and then salted out and precipitated. By separating the solid by filtration, the sodium salt of the compound represented by the above formula (1) can be obtained as a wet cake.
Moreover, after dissolving the obtained sodium salt wet cake in water, an acid such as hydrochloric acid is added to adjust the pH appropriately, and the precipitated solid is separated by filtration, whereby the compound represented by the above formula (1) is obtained. Or a mixture of a free acid and a sodium salt, in which a part of the compound represented by the formula (1) is a sodium salt.
Further, while stirring the wet cake of the free acid of the compound represented by the formula (1) with water, for example, potassium hydroxide, lithium hydroxide, aqueous ammonia or hydroxylation of the compound represented by the above formula (5) If it is made alkaline by adding a compound or the like, the corresponding potassium salt, lithium salt, ammonium salt, or quaternary ammonium salt of the above formula (5) can also be obtained. By limiting the number of moles of the above-mentioned salt to the number of moles of free acid, it is possible to prepare, for example, a mixed salt of lithium and sodium, and further a mixed salt of lithium, sodium, and ammonium. is there. The salt of the compound represented by the above formula (1) may change the physical properties such as solubility or the ink performance when used as an ink depending on the type of the salt. For this reason, it is also preferable to select the type of salt according to the target ink performance.

The compound represented by the above formula (1) of the present invention can be produced, for example, as follows. In addition, R ¹ , R ² , group A and group B used appropriately in the following formulas (AA ′) to (G ′), (F ″), and (AA) to (G) are respectively represented by the above formula (1 ) Represents the same meaning as in
With reference to the example described in JP-A-2004-75719, a compound represented by the following formula (AA ′) is converted to a methyl-ω-sulfonic acid derivative (BB ′) using sodium bisulfite and formalin. . Subsequently, sulfoazoline and a methyl-ω-sulfonic acid derivative of aniline were subjected to diazo coupling by a conventional method, followed by hydrolysis under alkaline conditions to obtain a compound represented by the following formula (C ′). Thereafter, the compound represented by the following formula (C ″) obtained by treating this compound with fuming sulfuric acid or the like is diazotized to obtain a methyl-ω-sulfonic acid derivative of the formula (BB ′) obtained above and 10 A compound represented by the following formula (D ′) is obtained by performing a coupling reaction at ˜40 ° C. and pH 2 to 5, followed by a hydrolysis reaction at 80 to 95 ° C. and pH 10.5 to 11.5. It is done.

  Next, a substituted or unsubstituted aliphatic amine represented by “HA” corresponding to the group A; a substituted or unsubstituted aromatic amine; a substituted or unsubstituted phenol; or an amine of a monoazo compound; A compound represented by the following formula (F ′) is obtained by condensing 1 equivalent and cyanuric halide, for example, 1 equivalent of cyanuric chloride, under weakly acidic conditions at a temperature of 0 to 20 ° C. and a pH of 5 to 7. Subsequently, 1 equivalent of the compound represented by the formula (D ′) obtained above and 1 equivalent of the compound represented by the following formula (F ′) are subjected to mildly acidic conditions at a temperature of 20 to 50 ° C. and a pH of 6 to 7. By condensing below, a compound represented by the following formula (G ′) is obtained.

Further, the compound represented by (G ′) has the following formula (F ″) obtained by condensing 1 equivalent of the compound represented by formula (D ′) and cyanuric halide, for example, 1 equivalent of cyanuric chloride. 1 equivalent of any of: a substituted or unsubstituted aliphatic amine represented by “HA” corresponding to the group A; a substituted or unsubstituted aromatic amine; a substituted or unsubstituted phenol; or an amine of a monoazo compound Can also be obtained by condensation.

  Further, the chlorine atom in the obtained compound represented by the formula (G ′) is preferably represented by “H—B” corresponding to the group B under the conditions of 75 to 90 ° C. and pH 7 to 9. Substituted or unsubstituted aliphatic amine; substituted with a substituted or unsubstituted aromatic amine, or hydrolyzed under basic conditions such as aqueous sodium hydroxide to introduce a hydroxy group by the above-described formula ( The water-soluble azo compound of the present invention represented by 1) can be obtained.

Moreover, the compound represented by the said Formula (2) of this invention is compoundable as follows. The rings substituted by R ³ , R ⁴ , n, x, and — (SO ₃ H) n, which are appropriately used in the following formulas (AA) to (H), include the ring represented by the broken line, respectively. It represents the same meaning as in (2).
By using the compounds represented by the following formulas (AA), (BB), (C) instead of the compounds represented by the above formulas (AA ′), (BB ′), (C ″), A compound represented by the following formula (D) can be obtained. In addition, all the compounds represented by the following formulas (AA) and (C) can be synthesized by a conventional method, or can be obtained as a commercial product.

  Next, for example, a monoazo compound represented by the following formula (E) corresponding to the above “HA” is used as “HA” in the same manner as described above, and corresponds to the above formula (F ′). A compound represented by the following formula (F) is obtained. Subsequently, it is represented by the following formula (G) corresponding to the above formula (G ′) in the same manner as above except that the compound represented by the following formula (F) is used instead of the above formula (F ′). A compound is obtained.

  Further, the chlorine atom in the obtained compound represented by the formula (G) was substituted with a compound represented by the following formula (H) corresponding to the substituted aliphatic amine represented by the above-mentioned “H-B”. By doing so, the water-soluble azo compound of the present invention represented by the above formula (2) can be obtained.

  A residue obtained by removing one hydrogen atom from the amino group of the monoazo compound represented by the above formula (E) is a preferable residue of the monoazo compound in the group A of the above formula (1). Preferable specific examples of the residue include the residues in Tables 1 and 2 below.

  Specific examples of the compound represented by the formula (H) include aminomethylsulfonic acid, taurine, homotaurine, preferably taurine.

Next, preferred specific examples of the water-soluble azo compound of the present invention are shown in Tables 3 and 4 below.

The compound represented by the above formula (1) of the present invention can be isolated as a solid free acid by adding a mineral acid such as hydrochloric acid after the coupling reaction, and the resulting free acid solid is either water or For example, inorganic salts contained as impurities, such as sodium chloride and sodium sulfate, can be removed by washing with acidic water such as hydrochloric acid.
By treating the free acid of the water-soluble azo compound of the present invention obtained as described above with a desired inorganic or organic base in an aqueous medium, a solution of the corresponding salt of the compound can be obtained. The aqueous medium usually means a mixed solution of a water-soluble organic solvent and water.
Examples of the inorganic base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, or alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate, and ammonium hydroxide (ammonia water). ) And the like.
Examples of the organic base include, but are not limited to, quaternary ammonium salts represented by the above formula (5), for example, salts of alkanolamines such as diethanolamine and triethanolamine.

The dyes of the present invention are suitable for the dyeing of natural and synthetic fiber materials or blends, and also for the production of writing inks and in particular ink jet recording ink compositions.
The reaction liquid containing the water-soluble azo compound of the present invention, such as the reaction liquid in the final step in the synthesis reaction of the compound, can also be used directly for the production of the ink composition of the present invention. However, the compound may be isolated from the reaction solution by a method such as crystallization or spray drying, and then dried as necessary, and an ink composition may be prepared using the obtained compound. it can. In the ink composition of the present invention, the water-soluble azo compound of the present invention is used as a pigment, and is usually 0.1 to 20% by mass, more preferably 1 to 10% by mass, and still more preferably 2% in the total mass of the ink composition. Contains ~ 8% by mass.

  In the ink composition of the present invention, the compound represented by the formula (1) is dissolved in water or an aqueous medium (a mixed solution of a water-soluble organic solvent and water), and an ink preparation agent is added as necessary. Is. When this ink composition is used as an ink for an ink jet printer, a metal cation chloride contained as an impurity, such as sodium chloride; sulfate, such as sodium sulfate; Is preferred. In this case, for example, the total content of sodium chloride and sodium sulfate is about 1% by mass or less in the total mass of the water-soluble azo compound of the present invention. In order to produce the compound having a small amount of inorganic impurities, for example, a method using a known reverse osmosis membrane or a dried product or wet cake of the compound of the present invention or a salt thereof, a mixed solvent of C1-C4 alcohol such as methanol and water. In addition to the medium, the suspension is purified, and the solid is filtered off and dried, and then desalted.

  The ink composition of the present invention is prepared using water as a medium, and may contain a water-soluble organic solvent as necessary within a range that does not impair the effects of the present invention. The water-soluble organic solvent may have the same function as a dye solubilizer, a drying inhibitor (wetting agent), a viscosity modifier, a penetration accelerator, a surface tension modifier, an antifoaming agent, and the like. It is preferable to contain it in the product. Other ink preparation agents include, for example, antiseptic / antifungal agents, pH adjusting agents, chelating reagents, rust preventing agents, UV absorbers, viscosity adjusting agents, dye dissolving agents, antifading agents, emulsion stabilizers, surface tension adjusting agents. , Known additives such as antifoaming agents, dispersants, and dispersion stabilizers. The content of the water-soluble organic solvent is 0 to 60% by mass, preferably 10 to 50% by mass, and the ink preparation agent is 0 to 20% by mass, preferably 0 to 15% by mass, based on the entire ink. % Is good. The remainder other than the above is water.

  Examples of water-soluble organic solvents that can be used in the present invention include C1-C4 alkanols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert-butanol; N, N-dimethyl Amides such as formamide or N, N-dimethylacetamide; 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido-2-one Heterocyclic ketones such as: ketones such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one or keto alcohols; cyclic ethers such as tetrahydrofuran, dioxane; ethylene glycol, 1,2- or 1,3- Propylene glycol, 1,2- or 1,4-butyle Mono, oligo or polyalkylene glycols having C2-C6 alkylene units such as glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, or thiodiglycol Or thioglycol; polyol (triol) such as glycerin, hexane-1,2,6-triol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol) , Triethylene glycol monomethyl ether, triethylene glycol mono C1-C4 monoalkyl ethers of polyhydric alcohols such as Chirueteru; gamma-butyrolactone or dimethyl sulfoxide and the like.

  Preferred as the above water-soluble organic solvent are isopropanol, glycerin, mono-, di- or triethylene glycol, dipropylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol, more preferably isopropanol, Glycerin, diethylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol. These water-soluble organic solvents are used alone or in combination.

Examples of antiseptic / antifungal agents include organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, benzothiazole, nitrile, pyridine, 8- Oxyquinoline, isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, adamantane, dithiocarbamate, brominated indanone And benzyl bromacetate compounds.
Examples of the organic halogen compound include sodium pentachlorophenol, examples of the pyridine oxide compound include sodium 2-pyridinethiol-1-oxide, and examples of the isothiazoline compound include 1,2-benzisothiazoline. -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 Examples thereof include magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, and 2-methyl-4-isothiazolin-3-one calcium chloride.
Examples of other antiseptic / antifungal agents include sodium sorbate, sodium benzoate, and sodium acetate. Other specific examples of antiseptic / antifungal agents include, for example, trade names Proxel GXL (S) and Proxel XL-2 (S) manufactured by Avecia.

  As the pH adjuster, any substance can be used as long as it can control the pH of the ink within the range of 6.0 to 11.0 for the purpose of improving the storage stability of the ink. For example, alkanolamines such as diethanolamine and triethanolamine, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide, or alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate. And carbonates.

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

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

  Examples of the ultraviolet absorber include a compound that emits fluorescence by absorbing ultraviolet rays typified by benzophenone compounds, benzotriazole compounds, cinnamic acid compounds, triazine compounds, stilbene compounds, or benzoxazole compounds, so-called fluorescence. Brightening agents can also be used.

  Examples of the viscosity modifier include water-soluble polymer compounds in addition to water-soluble organic solvents, such as polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

  Examples of the dye solubilizer include urea, ε-caprolactam, ethylene carbonate, and the like. It is preferred to use urea.

  The anti-fading agent is used for the purpose of improving image storage stability. As the antifading agent, various organic and metal complex antifading agents can be used. Organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles, and metal complexes include There are nickel complexes and zinc complexes.

  Examples of the surface tension adjusting agent include surfactants, and examples include anionic surfactants, amphoteric surfactants, cationic surfactants, and nonionic surfactants.

  Anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and their salts, N-acyl methyl taurates, alkyl sulfates polyoxyalkyl ether sulfates Salt, 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, diethylsulfate , Diethylhexylsyl sulfosuccinate, dioctyl sulfosuccinate and the like.

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

  Amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, and other 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-di Chill-1-hexyne-3-ol acetylene alcohol such as, for example, as another embodiment, manufactured by Nissin Chemical Industry Co., Ltd. trade name Surfynol 104,82,465, Olfine STG and the like.

  As the antifoaming agent, a highly oxidized oil-based, glycerin fatty acid ester-based, fluorine-based, or silicone-based compound is used as necessary.

  These ink preparation agents are used alone or in combination. The surface tension of the ink composition of the present invention is usually 25 to 70 mN / m, more preferably 25 to 60 mN / m. The viscosity of the ink composition of the present invention is preferably 30 mPa · s or less, and more preferably adjusted to 20 mPa · s or less.

  In order to produce the ink composition of the present invention, there is no particular limitation on the order in which each agent such as an ink preparation agent is dissolved. In preparing the composition, the water to be used is preferably one having few impurities such as ion exchange water or distilled water. Furthermore, if necessary, fine filtration may be performed using a membrane filter to remove impurities. When used as ink for an inkjet printer, it is preferable to perform fine filtration. The pore size of the filter for performing microfiltration is usually 1 to 0.1 microns, preferably 0.5 to 0.1 microns.

  The ink composition containing the water-soluble azo compound of the present invention is suitable for use in printing, copying, marking, writing, drawing, stamping, or recording (printing), particularly in inkjet recording. In addition, the ink composition of the present invention hardly causes solid precipitation even when dried in the vicinity of the nozzles of an ink jet printer, and for this reason, head clogging is also unlikely to occur. Furthermore, when the ink composition of the present invention is used for ink jet recording, it has a high quality and good color density of yellow, orange, brown, and red with good resistance to water, light, ozone, nitrogen oxide gas, and friction. A printed product is obtained.

The ink composition of the present invention can be obtained by mixing and stirring the components such as the ink preparation agent in an arbitrary order. Moreover, in order to adjust the color as an ink composition, in addition to the water-soluble azo compound of the present invention, other dyes having various hues may be mixed within a range where the effects of the present invention are not inhibited. In that case, known yellow (for example, CI Direct Yellow 34, CI Direct Yellow 58, CI Direct Yellow 86, CI Direct Yellow 132, etc.) and orange (for example, CI Direct Yellow 58, respectively) Direct Orange 26, CI Direct Orange 29, CI Direct Orange 49, etc.), Brown, Scarlet, Red (eg, CI Direct Red 62, CI Direct Red 75, CI Direct Red 79, CI Direct Red 80, CI Direct Red 84, etc.), magenta, violet, blue, navy, cyan, green, and other color pigments can be mixed and used.

  When the water-soluble azo compound of the present invention is used for toning black ink, any black pigment may be used as a blending partner, for example, known compounds listed in Table 5 below. However, it is not limited to these.

In addition to the known black pigment, for example, the pigment described in each example of WO 03/106572, which is considered to have good light resistance and ozone resistance; The dyes described in the examples of WO2005 / 052065; described in Tables 1 to 6 of JP-A-2005-220338, which are excellent in hue, print density, light fastness, heat fastness and ozone resistance A black ink is obtained by blending the dye; and the dye described in the compound examples 1 to 38 of JP-A-2007-314602, which have good water resistance and light resistance, with the water-soluble azo compound of the present invention. You can also.

  In order to provide high-definition images in inkjet printers, black inks are high-density ink (dark black ink) and low-density ink (light black ink), or two or more black colors. Some inks are loaded in one printer. In that case, a high-concentration ink composition and a low-concentration ink composition containing only the water-soluble azo compound of the present invention as a pigment; or a black ink composition containing the compound and another black pigment; Each ink composition may be prepared and used as an ink set. Moreover, you may use or mix | blend this compound only in any one. In addition to the water-soluble azo compound of the present invention, an ink composition using a known yellow-orange-brown-red dye or the like may be used. Examples of known dyes include the above-mentioned C.I. I. Although the dye etc. which the number was provided can be mentioned, it is not limited to these.

  The colored product of the present invention is a substance colored with the water-soluble azo compound of the present invention or an ink composition containing the compound. There are no particular restrictions on the material of the colored body, for example, information transmission sheets such as paper and film, fibers and fabrics (cellulose, nylon, wool, etc.), leather, base materials for color filters, etc. Anything may be used, but the information transmission sheet is preferable, although not limited thereto. Examples of the coloring method include a printing method such as a dip dyeing method, a textile printing method, and screen printing, an ink jet recording method using an ink jet printer, and the ink jet recording method is preferable.

The information transmission sheet is preferably a surface-treated sheet, specifically, a sheet such as paper, synthetic paper, or film provided with an ink receiving layer. The ink receiving layer may be formed by, for example, impregnating or coating the base material with a cationic polymer; or inorganic fine particles capable of absorbing the pigment in the ink, such as porous silica, alumina sol, and special ceramics, with polyvinyl alcohol or polyvinyl pyrrolidone. A method of coating the surface of the substrate together with a hydrophilic polymer such as
Those provided with such an ink receiving layer are usually called ink jet exclusive paper, ink jet exclusive film, glossy paper, or glossy film.
Among these, the porous silica, alumina sol, special ceramics, etc. mentioned above are coated on the substrate surface because they are easily affected by gases having an oxidizing action in the air, that is, ozone gas and nitrogen oxide gas. This is a special inkjet paper.
An example of a typical commercially available paper for inkjet use is Canon Inc., trade name Professional Photo Paper, Super Photo Paper, and Matt Photo Paper; Seiko Epson Corporation trade name Photo Paper Crispia ( High gloss), photo paper (gloss), photo matte paper; manufactured by Nippon Hewlett-Packard Co., Ltd., trade name Advanced Photo Paper (gloss); manufactured by Fuji Film Co., Ltd., trade name photo finish photo finish Pro;
Since the ink composition of the present invention is excellent in the resistance to the gas having the above oxidizing action, it provides an excellent recorded image with little discoloration even when recording on such a recording material. It can also be used for plain paper.

In order to record on a recording material by the ink jet recording method of the present invention, for example, a container filled with the ink composition described above is set at a predetermined position of an ink jet printer and recorded on the recording material by a normal method. Good. In the inkjet recording method of the present invention, a magenta ink, a cyan ink, and, if necessary, a green ink, a blue (or violet) ink, a red ink, and a black ink can be used in combination with the ink composition of the present invention. In this case, the inks of the respective colors are injected into the respective containers, and these containers are used in a predetermined position of the ink jet printer.
Some inkjet printers use, for example, a piezo method using mechanical vibration; a bubble jet (registered trademark) method using bubbles generated by heating; and the like. The ink jet recording method of the present invention can be used by any method.

The ink composition of the present invention has a color of yellow to orange to brown to red, and particularly has a high color density of an image recorded on ink jet dedicated paper or glossy paper, and has a hue suitable for the ink jet recording method. In addition, the recorded image is characterized by various fastnesses such as water resistance, light resistance, and moisture resistance, particularly ozone gas resistance.
The ink composition of the present invention does not precipitate or separate during storage, and has extremely high storage stability. Further, when the ink composition of the present invention is used for ink jet recording, solid precipitation due to drying of the ink composition in the vicinity of the nozzle is very unlikely to occur, and the ejector (ink head) is not blocked. The ink composition of the present invention is used in a case where a continuous ink jet printer is used and ink is recirculated at a relatively long time interval; or an intermittent use is performed by an on-demand ink jet printer; Does not cause changes in physical properties.

Hereinafter, the present invention will be described more specifically with reference to examples. In the text, “parts” and “%” are based on mass unless otherwise specified, and the reaction temperature is also the internal temperature. Operations such as each reaction and crystallization in the examples were carried out with stirring unless otherwise specified.
In addition, (lambda) max (maximum absorption wavelength) of each compound synthesize | combined showed the measured value in the range of 300 nm to 800 nm in the aqueous solution of pH 7-8. The water-soluble azo compounds of the present invention obtained in the examples are all sodium salts, but for the sake of convenience, their chemical structural formulas are shown as free acids. However, as described above, a free acid or an alkali metal salt other than a sodium salt can be easily obtained by using an appropriate method, and the present invention is not limited to this example.

Example 1
(1)
A monoazo compound represented by the following formula (6) (commercially available as a product of Chemco International) 35.7 parts is dissolved in 200 parts of water while adjusting the pH to 6 with sodium hydroxide, and then sodium nitrite 7.2 Part was added. This solution was added dropwise to 300 parts of 5% hydrochloric acid at 0 to 10 ° C. over 30 minutes, followed by stirring at 20 ° C. or lower for 1 hour to carry out a diazotization reaction to prepare a diazo reaction liquid.

On the other hand, 10.7 parts of 3-methylaniline was converted into a methyl-ω-sulfonic acid derivative by a conventional method using 130 parts of water, 10.4 parts of sodium bisulfite and 8.6 parts of 35% formalin. .
The obtained methyl-ω-sulfonic acid derivative was added to the previously prepared diazo reaction solution, and the mixture was stirred at 0 to 15 ° C. and pH 2 to 4 for 5 hours. The reaction solution was adjusted to pH 11 with sodium hydroxide, stirred at 80 to 95 ° C. for 5 hours while maintaining the same pH, further salted out by adding 100 parts of sodium chloride, and the precipitated solid was collected by filtration. 120 parts of a compound represented by the following formula (7) was obtained as a wet cake.

(2)
Lion Co., Ltd., trade name: Leocol TD90 (surfactant) 0.10 part was added to 250 parts of ice water and stirred vigorously, and 12.9 parts of cyanuric chloride was added thereto, and 0 to 5 ° C. for 30 minutes. Stir to obtain a suspension.
On the other hand, 25.0 parts of the compound represented by the above formula (6) was dissolved in 200 parts of water, and the above suspension was dropped into this solution over 30 minutes. After completion of dropping, the mixture was stirred at pH 5 to 7 and 0 to 15 ° C. for 6 hours to obtain a reaction solution.

(3)
The wet cake of 120 parts of the compound represented by the above formula (7) obtained in Example 1 (1) was dissolved in 300 parts of water, and the reaction solution obtained in Example 1 (2) was dissolved for 30 minutes. It was dripped over. After completion of dropping, the mixture was stirred at pH 6-7, 25-50 ° C. for 6 hours, 26.3 parts of taurine was added, and the mixture was further stirred at pH 7-9, 75-90 ° C. for 3 hours. After cooling the obtained reaction liquid to 20-25 degreeC, 800 parts of acetone was added to this reaction liquid, and it stirred at 20-25 degreeC for 1 hour. The precipitated solid was separated by filtration to obtain 120.0 parts of a wet cake. This wet cake was dried with a hot air dryer at 80 ° C. to obtain 50.0 parts of the water-soluble azo compound (λmax 385 nm) of the present invention represented by the following formula (8).

Example 2
(A) Preparation of Ink An ink composition was prepared by mixing the components shown in Table 6 below, and a test ink was obtained by filtering through a 0.45 μm membrane filter. At this time, ion-exchanged water is used as the water, and the pH of the ink composition is adjusted with an aqueous ammonium hydroxide solution (ammonia water) so that the pH is 8 to 9, and the total amount is suitably 100.0 parts. Water was added. This ink preparation is Example 2.
The obtained water-based ink composition did not undergo precipitation separation during storage and did not change its physical properties even after long-term storage.

Table 6
Compound obtained in Example 1 3.5 parts Glycerin 5.0 parts Urea 5.0 parts N-methyl-2-pyrrolidone 4.0 parts Isopropyl alcohol 3.0 parts Butyl carbitol 2.0 parts Surfactant 0.1 part (Surfinol 105 manufactured by Nissin Chemical)
Water + ammonium hydroxide aqueous solution 77.4 parts Total 100.0 parts

Comparative Example 1
A comparison was made in the same manner as in Example 2 except that the compound represented by the following formula (4) disclosed in Patent Document 2 was used instead of the water-soluble azo compound of the present invention obtained in Example 1. An ink for use was obtained. The preparation of this comparative ink is referred to as Comparative Example 1.

(B) Glossy paper 1 (product name: Professional Photo Paper PR-, manufactured by Canon Inc.) using an ink jet printer manufactured by Canon and product name PIXUS iP4100 using the inks obtained in Inkjet Recording Example 2 and Comparative Example 1, respectively. 101), glossy paper 2 [trade name photographic paper Krispia (high gloss) manufactured by EPSON Co., Ltd.], two types of information recording sheets (inkjet dedicated paper) were subjected to inkjet recording.
At the time of printing, an image pattern was prepared so that the reflection density was obtained with several gradations, and a printed matter for evaluation test was obtained.

(C) Evaluation of Recorded Image Each printed matter obtained using the inks of Example 2 and Comparative Example 1 was evaluated for ozone gas resistance with respect to changes in image density before and after the test.
The density change of the printed image is measured by using a colorimeter manufactured by GRETAG-MACBETH, trade name SpectroEye, and measuring the gradation part where the reflection density D value of the printed matter before the test is in the range of 0.3 to 0.5. Measured by color.
The test was performed for each of glossy papers 1 and 2, and the test results are shown in Table 7 below.
The specific test method is as follows.

Ozone gas resistance test, manufactured by Suga Test Instruments Co., Ltd., product name Ozone concentration meter with ozone concentration 40ppm, humidity 60% RH, temperature 24 ° C, each printed matter for 8 hours (short time ozone gas resistance test) And left for 24 hours (long-term ozone gas resistance test). After completion of the test, the colorimetry was performed using the above colorimeter, and the residual ratio of the pigment of each printed matter was determined by the formula (reflection density after test / reflection density before test) × 100 (%). The test results were evaluated according to the following criteria. In addition, the one where a pigment | dye residual rate is larger is better.

1) Short-time test ○: Residual rate 95% or more Δ: Residual rate 70% or more and less than 95% ×: Residual rate less than 70%

2) Long-term test ○: Residual rate 90% or more △: Residual rate 60% or more and less than 90% ×: Residual rate less than 60%

Table 7: Ozone gas resistance test results

Example 2 1) Short time 2) Long time Glossy paper 1 △ △
Glossy paper 2 ○ ○
Comparative Example 1
Glossy paper 1 × ×
Glossy paper 2 △ △

As is clear from the results in Table 7, the printed matter obtained using the ink of Example 2 was obtained when the ink of Comparative Example 1 was used in both ozone gas resistance tests for a short time and for a long time. The dye residual ratio was larger than that.
From the above results, the fastness of the printed matter obtained with the ink containing the water-soluble azo compound of the present invention is very excellent as compared with the image of the conventional compound used in Comparative Example 1, and in particular, the ink jet recording image. It can be seen that it is extremely excellent in ozone gas resistance required for the above. Therefore, the water-soluble azo compound of the present invention is extremely useful as a black pigment for ink jet recording.

  The ink composition containing the compound of the present invention is suitably used as an ink liquid for ink jet recording and a writing instrument.

Claims (12)

A water-soluble azo compound represented by the following formula (1) or a salt thereof,

[In Formula (1),
R ¹ and R ² are each independently a hydrogen atom; a chlorine atom; a hydroxy group; a sulfo group; a carboxy group; a sulfamoyl group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted group, a hydroxy group, or an unsubstituted C1 group. A C1-C4 alkoxy group substituted with a -C4 alkoxy group, a hydroxy C1-C4 alkoxy group or a carboxy group; a mono- or di-C1-C4 alkylamino group which is unsubstituted or substituted with a hydroxy group, a sulfo group or a carboxy group An unsubstituted or C1-C4 alkylcarbonylamino group substituted with a hydroxy group or a carboxy group; an N'-C1-C4 alkylureido group unsubstituted or substituted with a hydroxy group, a sulfo group or a carboxy group; Unsubstituted or benzene ring is chlorine atom, unsubstituted C1-C4 alkyl group, nitro group, sulfo group Is a phenylamino group substituted with a carboxy group; unsubstituted or a benzoylamino group in which the benzene ring is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group or a carboxy group; or unsubstituted Or a phenylsulfonylamino group in which the benzene ring is substituted with a chlorine atom, an unsubstituted C1-C4 alkyl group, a nitro group, a sulfo group, or a carboxy group;
Group A is a substituted or unsubstituted aliphatic amino group; a substituted or unsubstituted aromatic amino group; a substituted or unsubstituted phenoxy group; or a residue of a monoazo compound,
The group B represents a substituted or unsubstituted aliphatic amino group; a substituted or unsubstituted aromatic amino group; or a hydroxy group, respectively. ].   The water-soluble group according to claim 1, wherein the group A is a residue of a monoazo compound, and the group B is an aliphatic amino group having a carboxy group or a sulfo group; an aromatic amino group having a carboxy group or a sulfo group; or a hydroxy group. Azo compounds or salts thereof.   The water-soluble azo compound or a salt thereof according to claim 1, wherein the group A is a residue of a monoazo compound, and the group B is an aliphatic amino group having a carboxy group or a sulfo group. A water-soluble azo compound represented by the following formula (2) or a salt thereof,

[In Formula (2),
n is an integer from 1 to 3,
x is an integer from 1 to 3,
R ³ and R ⁴ are each independently a hydrogen atom; a chlorine atom; a hydroxy group; a sulfo group; an unsubstituted C1-C4 alkyl group; an unsubstituted or hydroxy group, an unsubstituted C1-C4 alkoxy group, a hydroxy C1-C4 C1-C4 alkoxy group substituted with an alkoxy group or a sulfo group; unsubstituted or mono- or di-C1-C4 alkylamino group substituted with a hydroxy group or a sulfo group; C1 substituted with an unsubstituted or hydroxy group -C4 alkylcarbonylamino group; N'-C1-C4 alkylureido group unsubstituted or substituted with a hydroxy group or a sulfo group; unsubstituted or a benzene ring is a chlorine atom, an unsubstituted C1-C4 alkyl group, A phenylamino group substituted by a nitro group or a sulfo group; unsubstituted or a benzene ring having a chlorine atom, an unsubstituted C1-C4 alkyl group, Benzoylamino group substituted with b group or a sulfo group; unsubstituted or substituted benzene ring is a chlorine atom, an unsubstituted C1-C4 alkyl group, phenyl sulfonylamino group substituted with a nitro group or a sulfo group; a,
The ring substituted by — (SO ₃ H) n represents a benzene ring when a ring represented by a broken line is not present; and a naphthalene ring when a ring represented by a broken line is present. ]. In equation (2),
i)
There is no ring represented by a broken line,
R ³ and R ⁴ are each independently a hydrogen atom; a sulfo group; an unsubstituted or sulfo-substituted C1-C4 alkoxy group;
n is an integer of 1 or
ii)
There is a ring represented by a broken line,
R ³ and R ⁴ are each independently a hydrogen atom; a sulfo group; an unsubstituted C1-C4 alkyl group; an unsubstituted C1-C4 alkylcarbonylamino group; an unsubstituted or sulfo-substituted C1-C4 alkoxy group;
n is an integer of 2 or 3,
The water-soluble azo compound or a salt thereof according to claim 4. There is no ring represented by a broken line,
One of R ³ and R ⁴ is a hydrogen atom, the other is a sulfo group,
The water-soluble azo compound or a salt thereof according to claim 4 or 5, wherein n is an integer of 1 and x is an integer of 2. An ink composition comprising at least one water-soluble azo compound or salt thereof according to any one of claims 1 to 6 as a coloring matter. 8. An ink jet recording method for performing recording by using the ink composition according to claim 7 as ink, and ejecting ink droplets of the ink in accordance with an ejection signal to adhere to the recording material. The ink jet recording method according to claim 8, wherein the recording material is an information transmission sheet. The ink jet recording method according to claim 9, wherein the information transmission sheet is a sheet containing a porous white inorganic substance. An ink jet printer loaded with a container containing the ink composition according to claim 7. The colored body colored with the water-soluble azo compound or its salt as described in any one of Claims 1 thru | or 6.