JP2010155936A - Azo compound, ink composition, method for recording and colored article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an azo compound for black ink that has high solubility in a medium mainly composed of water, is stable even after long-term storage of a highly concentrated aqueous solution or ink thereof, is excellent in fastness of a recorded image, particularly excellent in light resistance and ozone gas resistance and gives a colorless and high-grade black recorded image and to provide an ink composition containing the compound. <P>SOLUTION: The azo compound represented by formula (1) or salts thereof is provided. In the formula, R<SP>1</SP>represents an unsubstituted alkyl group or the like; R<SP>2</SP>represents a cyano group or the like; R<SP>3</SP>and R<SP>4</SP>each independently represent a hydrogen atom, a sulfo group or the like; R<SP>5</SP>to R<SP>7</SP>each independently represent a sulfo-substituted alkoxy group or the like; the group A represents a substituted naphthyl group or the like; and the group B represents a substituted thiazole group or the like. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

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 is quiet because it does not generate sound because the recording head and the recording material are not in direct contact. In addition, it has been rapidly spreading in recent years due to the feature of being easy to downsize and speed up, and is expected to grow greatly in the future. Conventionally, water-based inks in which water-soluble pigments are dissolved in aqueous media have been used as fountain pens, felt-tip pens, and ink jet recording inks. In these 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. The water-soluble dye used is required to have a particularly high solubility in water and a high solubility in the water-soluble organic solvent added to the ink. Further, the formed image is required to have image fastness such as water resistance, light resistance, gas resistance and moisture resistance.

Among these, the gas resistance is resistance to a phenomenon in which ozone gas having an oxidizing action existing in the air acts on the dye on the recording paper and discolors 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 and fading phenomenon of ink jet recorded images, and particularly, ozone gas resistance is regarded as important. 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 or the like is remarkably observed on such recording paper. Since the discoloration phenomenon due to the oxidizing gas is characteristic of ink jet images, improvement of 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 of ink jet recording, further improvement in light resistance, gas resistance, moisture resistance, water resistance and the like is strongly demanded for ink jet recorded images.

Various hues of ink are prepared from various dyes, 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 market demand. 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 poor metamerism. 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 been the most important issue in recent years, for example, 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 2 to 6 and the like. Patent Documents 3 and 4 also disclose trisazo compounds, but these trisazo compounds are obtained by further bonding two benzimidazolopyridone skeletons with azo structures to both ends of a linking group containing an azo structure. Nothing similar to the asymmetric azo compound of the present invention having a symmetrical structure is disclosed. Patent Document 6 discloses the use of a trisazo compound and a water-soluble black compound for inkjet recording. These compounds have high fastness but tend to have too high saturation as black, and are insufficient as achromatic and high-quality black.

International Publication No. 2005/054374 Pamphlet International Publication No. 2004/050768 Pamphlet German Patent No. 2000004488 German Patent No. 2023295 JP 05-134435 A International Publication No. 2007/077931 Pamphlet

An object of the present invention is to provide an azo compound or a salt thereof used for a black ink particularly suitable for ink jet recording, and an ink composition containing the compound.

As a result of intensive studies to solve the problems as described above, the present inventors have found that a specific azo compound can solve the problems, and have completed the present invention. That is, the present invention
1) An azo compound represented by the following formula (1) or a salt thereof,

[In Formula (1),
R ¹ represents an unsubstituted C1-C4 alkyl group; a carboxy-substituted C1-C4 alkyl group; an unsubstituted phenyl group; a sulfo-substituted phenyl 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 represent a hydrogen atom; a methyl group; a chlorine atom; or a sulfo group;
The ring in which R ⁵ to R ⁷ are substituted represents a benzene ring when a ring represented by a broken line is not present; or a naphthalene ring when a ring represented by a broken line is present;
R ⁵ to R ⁷ are each independently a hydrogen atom; carboxy group; sulfo group; hydroxy group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; hydroxy group, unsubstituted C1-C4 alkoxy group, hydroxy A C1-C4 alkoxy group substituted with a C1-C4 alkoxy group, a sulfo group or a carboxy group; an acetylamino group;
Group A is a substituted phenyl group or a substituted naphthyl group,
The substituent of the group A includes a carboxy group; a sulfo group; a hydroxy group; an unsubstituted benzenesulfonyloxy group; a benzenesulfonyloxy group in which the benzene ring is substituted with a methyl group, a nitro group or a chlorine atom; a chlorine atom; a cyano group; Nitro group; sulfamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; C1-C4 alkoxy group substituted by hydroxy group, unsubstituted C1-C4 alkoxy group, sulfo group or carboxy group; unsubstituted A C1-C4 alkylsulfonyl group; a C1-C4 alkylsulfonyl group substituted with a hydroxy group, a sulfo group or a carboxy group; an unsubstituted C1-C8 alkylaminosulfonyl group; a C1-substituted with a hydroxy group, a sulfo group or a carboxy group; C8 alkylaminosulfonyl group; unsubstituted C1-C8 alkylcarbonyl Carboxy-substituted C1-C8 alkylcarbonylamino group; unsubstituted benzoylamino group; benzoylamino group in which the benzene ring is substituted with a sulfo group, a carboxy group, a chlorine atom or a C1-C4 alkyl group; an unsubstituted benzenesulfonylamino group A benzenesulfonylamino group in which the benzene ring is substituted with a methyl group, a nitro group or a chlorine atom; a trifluoromethyl group; an acetyl group; and a benzoyl group; a group selected from the group consisting of:
Group B is a divalent substituted thiophene group or a divalent substituted thiazole group bonded to an azo group at the 2-position and 5-position,
The substituent of the group B is cyano group; carbamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted phenyl group; benzene ring is methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group Group, carbamoyl group, phenyl group substituted with fluorine atom, chlorine atom or bromine atom; unsubstituted naphthyl group; and naphthalene ring is methyl group, bromine atom, carboxy group, sulfo group, unsubstituted C1-C4 alkoxy group, Or a naphthyl group substituted with a sulfo-substituted C1-C4 alkoxy group; a group selected from the group consisting of: ],
2)
The azo compound or a salt thereof according to the above 1) represented by the following formula (2):

[In Formula (2),
R ¹ to R ⁷ , group A and group B have the same meaning as in formula (1). ],

3)
The azo compound or salt thereof according to 1) or 2) above, wherein the group B is represented by the following formula (3) or (4):

[In Formula (3),
R ⁸ represents a cyano group or a carbamoyl group,
R ⁹ is a cyano group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; the benzene ring is a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group, carbamoyl group A phenyl group substituted with a fluorine atom, a chlorine atom or a bromine atom; an unsubstituted naphthyl group; and a naphthalene ring is a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group, or a sulfo-substituted C1 A naphthyl group substituted with a -C4 alkoxy group; represents a group selected from the group consisting of:
^* 1 represents a bond with the azo group to which the group A is bonded,
^* 2 represents a bond to the azo group to which the ring substituted by R ⁵ to R ⁷ is bonded. ],

[In Formula (4),
R ¹⁰ is a cyano group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; the benzene ring is a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group, carbamoyl group A phenyl group substituted with a fluorine atom, a chlorine atom or a bromine atom; an unsubstituted naphthyl group; and a naphthalene ring is a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group, or a sulfo-substituted C1 A naphthyl group substituted with a -C4 alkoxy group; represents a group selected from the group consisting of:
^* 3 represents a bond with the azo group to which the group A is bonded,
^{* 4,} a bond to the azo group ring from R ⁵ R ⁷ is substituted are attached represent respectively. ],

4)
Group B is represented by formula (3), and in formula (3):
R ⁸ is a cyano group or a carbamoyl group,
R ⁹ is an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; a phenyl group in which the benzene ring is substituted with a methyl group, an acetylamino group, a nitro group, a sulfo group, a carboxy group, or a chlorine atom; an unsubstituted naphthyl group; Or a naphthyl group in which the naphthalene ring is substituted with an unsubstituted C1-C4 alkoxy group, a sulfo group or a carboxy group;
Or
Group B is represented by formula (4), and in formula (4):
R ¹⁰ is an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; a phenyl group in which the benzene ring is substituted with a methyl group, an acetylamino group, a nitro group, a sulfo group, a carboxy group, or a chlorine atom; an unsubstituted naphthyl group; Or a naphthyl group in which the naphthalene ring is substituted with an unsubstituted C1-C4 alkoxy group, a sulfo group or a carboxy group;
The azo compound or salt thereof according to any one of 1) to 3) above,
5)
The azo compound or a salt thereof according to any one of 1) to 4), wherein the group A is represented by the following formula (5) or (6):

[In Formula (5),
R ^{11 to} R ¹³ are each independently a hydrogen atom; a carboxy group; a sulfo group; a hydroxy group; an unsubstituted benzenesulfonyloxy group; a benzenesulfonyloxy group in which the benzene ring is substituted with a methyl group, a nitro group or a chlorine atom; Cyano group; nitro group; sulfamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; C1-C4 alkoxy group substituted with a hydroxy group, a C1-C4 alkoxy group, a sulfo group or a carboxy group Unsubstituted C1-C4 alkylsulfonyl group; C1-C4 alkylsulfonyl group substituted with a hydroxy group, sulfo group or carboxy group; unsubstituted C1-C8 alkylaminosulfonyl group; substituted with a hydroxy group, sulfo group or carboxy group; A C1-C8 alkylaminosulfonyl group; unsubstituted C1-C8 Carboxy-substituted C1-C8 alkylcarbonylamino group; unsubstituted benzoylamino group; benzoylamino group in which the benzene ring is substituted with a sulfo group or an unsubstituted C1-C4 alkyl group; unsubstituted benzenesulfonylamino group; benzene A benzenesulfonylamino group in which the ring is substituted with a methyl group, a nitro group or a chlorine atom; a trifluoromethyl group; an acetyl group; or a benzoyl group. ],

[In Formula (6),
R ^{14 to} R ¹⁷ are each independently a hydrogen atom; a carboxy group; a sulfo group; a hydroxy group; an unsubstituted benzenesulfonyloxy group; a benzenesulfonyloxy group in which the benzene ring is substituted with a methyl group, a nitro group, or a chlorine atom; Cyano group; nitro group; sulfamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; C1-C4 alkoxy group substituted with a hydroxy group, a C1-C4 alkoxy group, a sulfo group or a carboxy group Unsubstituted C1-C4 alkylsulfonyl group; C1-C4 alkylsulfonyl group substituted with a hydroxy group, sulfo group or carboxy group; unsubstituted C1-C8 alkylaminosulfonyl group; substituted with a hydroxy group, sulfo group or carboxy group; A C1-C8 alkylaminosulfonyl group; unsubstituted C1-C8 Carboxy-substituted C1-C8 alkylcarbonylamino group; unsubstituted benzoylamino group; benzoylamino group in which the benzene ring is substituted with a sulfo group or an unsubstituted C1-C4 alkyl group; unsubstituted benzenesulfonylamino group; benzene A benzenesulfonylamino group in which the ring is substituted with a methyl group, a nitro group or a chlorine atom; a trifluoromethyl group; an acetyl group; or a benzoyl group. ],

6)
A group B represented by the formula (3), R ⁸ is a cyano group or a carbamoyl group, R ⁹ is an unsubstituted phenyl group; a phenyl group in which the benzene ring is substituted with a methyl group, a methoxy group, an acetylamino group, or a chlorine atom The azo compound or the salt thereof according to any one of 3) to 5) above, which is an unsubstituted naphthyl group; or a naphthyl group in which a naphthalene ring is substituted with a methoxy group or a sulfo group;
7)
A group B represented by the formula (4), R ¹⁰ is an unsubstituted phenyl group; a phenyl group in which the benzene ring is substituted with a methyl group, a methoxy group, an acetylamino group, or a chlorine atom; an unsubstituted naphthyl group; or naphthalene The azo compound or a salt thereof according to any one of 3) to 5) above, wherein the ring is a methoxy group or a naphthyl group substituted with a sulfo group;
8)
Group A is represented by Formula (5), and R ^{11 to} R ¹³ are each independently a hydrogen atom, a sulfo group, a carboxy group, a sulfamoyl group, a chlorine atom, an acetylamino group, a nitro group, a benzoylamino group, a methoxy group, Or an azo compound or a salt thereof according to any one of 1) to 7) above, which is a carboxyethylsulfonyl group,
9)
Any one of the above 1) to 7), wherein the group A is represented by the formula (6), and R ^{14 to} R ¹⁷ are a hydrogen atom, a sulfo group, a methoxy group, a carboxymethoxy group, a sulfoethoxy group, or a sulfopropoxy group. The azo compound or a salt thereof according to the item,
10)
The azo compound according to any one of 2) to 9) above, wherein R ⁵ is a C1-C4 alkoxy group substituted with a sulfo group, R ⁶ is a hydrogen atom, and R ⁷ is an unsubstituted C1-C4 alkyl group. Its salt,
11)
The azo compound or salt thereof according to any one of 1) to 10) above, wherein R ¹ is a methyl group, R ² is a cyano group or a carbamoyl group, R ³ is a hydrogen atom, and R ⁴ is a sulfo group,
12)
The group B is represented by the formula (4), R ¹⁰ is a phenyl group or a 2-naphthyl group, 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 sulfo group, R The azo compound or a salt thereof according to any one of 3) to 5), and 7) to 11), wherein ⁵ is a sulfopropoxy group, R ⁶ is a hydrogen atom, and R ⁷ is a methyl group,
13)
Wherein the group A is represented by the formula (6), at least two of R ¹⁴ , R ¹⁶ and R ¹⁷ are sulfo groups, and R ¹⁵ is a hydrogen atom, 5) to 7) and 9) to 12) The azo compound or a salt thereof according to any one of the above,
14)
An ink composition containing at least one azo compound or salt thereof according to any one of 1) to 13) as a pigment;
15)
An ink jet recording method for recording on a recording material by using the ink composition described in 14) above as an ink and discharging ink droplets of the ink in accordance with a recording signal;
16)
The inkjet recording method according to 15) above, wherein the recording material is an information transmission sheet,
17)
The ink jet recording method according to 16) above, wherein the information transmission sheet is a sheet having an ink receiving layer containing a porous white inorganic substance,
18)
An inkjet printer loaded with a container containing the ink composition described in 14) above,
19)
A colored body colored with the azo compound or salt thereof according to any one of 1) to 13) above;
About.

Hereinafter, the term “azo compound of the present invention”, including both “the azo compound of the present invention or a salt thereof”, will be simply described.
Since the azo compound of the present invention is excellent in water solubility, it has good filterability with a membrane filter in the process of producing an ink composition, and the ink composition containing this has excellent stability during storage and ejection stability. ing. Further, the ink composition of the present invention containing this azo compound 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 is characterized by containing at least one azo compound of the present invention. The ink composition is suitably used for ink jet recording, and is excellent in both light resistance and ozone gas resistance when recorded on ink jet dedicated paper. Moreover, since it has an achromatic and high-quality black hue, the ink composition of the present invention is extremely useful as a black ink for inkjet recording.

Hereinafter, the present invention will be described in detail.
The azo compound represented by the formula (1) has a tautomer, and examples of the tautomer include the following formulas (7) and (8) in addition to the compound represented by the formula (1). It is done. These compounds are also included in the present invention. In formulas (7) and (8), R ^{1 to} R ⁷ , group A and group B have the same meaning as in formula (1) above.

In the above formulas (1) and (2), examples of the unsubstituted C1-C4 alkyl group for R ¹ include straight-chain or branched-chain groups, and straight-chain is preferable. Specific examples thereof include linear ones such as methyl, ethyl, n-propyl and n-butyl; branched ones such as isopropyl, isobutyl, sec-butyl and tert-butyl;

Examples of the carboxy-substituted C1-C4 alkyl group for R ¹ include those in which carboxy is substituted on any carbon atom of the unsubstituted C1-C4 alkyl group. The substitution position of carboxy is not particularly limited, but it is preferably substituted at the terminal, and the number of substitution of carboxy is 1 or 2, preferably 1. Specific examples include carboxymethyl and 2-carboxyethyl.

The sulfo-substituted phenyl group for R ¹ includes a phenyl group having 1 to 3, preferably 1 or 2 substituted sulfo groups, and the substitution position of sulfo is not particularly limited. Specific examples include 3-sulfophenyl, 4-sulfophenyl, 2,4-disulfophenyl, 3,5-disulfophenyl, and the like.

Preferable R ¹ includes an unsubstituted C1-C4 alkyl group, a carboxy-substituted C1-C4 alkyl group, and a sulfo-substituted phenyl group, and more preferably an unsubstituted C1-C4 alkyl group. Specific examples include methyl, n-propyl, carboxymethyl, and 4-sulfophenyl, more preferably methyl and n-propyl, and still more preferably methyl.

In the above formula (1), R ² represents a cyano group; a carbamoyl group; or a carboxy group. A cyano group or a carbamoyl group is 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 methyl group; a chlorine atom; or a sulfo group, preferably a hydrogen atom; a methyl group; or a sulfo group, more preferably a hydrogen atom. Or a sulfo group is mentioned.
Preferred combinations of R ³ and R ⁴ include a combination of R ³ is a hydrogen atom and R ⁴ is a sulfo group; or R ³ is a sulfo and R ⁴ is a hydrogen atom.

In the above formula (1), the ring in which R ⁵ to R ⁷ are substituted is a benzene ring when a ring represented by a broken line is not present; or a naphthalene ring when a ring represented by a broken line is present Represents. The ring in which R ⁵ to R ⁷ are substituted is preferably a benzene ring.

In the above formula (1), examples of the unsubstituted C1-C4 alkyl group in R ⁵ to R ⁷ include the same as the unsubstituted C1-C4 alkyl group in R ¹ , including preferable ones.

Examples of the unsubstituted C1-C4 alkoxy group in R ⁵ to R ⁷ include a straight chain or branched chain group, and a straight chain group is preferable. Specific examples thereof include linear ones such as methoxy, ethoxy, n-propoxy and n-butoxy; branched ones such as isopropoxy, sec-butoxy and tert-butoxy; More preferred is methoxy.

The C1-C4 alkoxy group substituted with a hydroxy group, an unsubstituted C1-C4 alkoxy group, a hydroxy C1-C4 alkoxy group, a sulfo group or a carboxy group in R ⁵ to R ⁷ is the above-mentioned unsubstituted C1-C4 alkoxy group. An arbitrary carbon atom includes those having the above-mentioned substituents, and the number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but it is preferably substituted at the end of the alkoxy group.
Specific examples include hydroxy-substituted ones such as 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy; methoxyethoxy, ethoxyethoxy, n-propoxyethoxy, isopropoxyethoxy, n-butoxyethoxy, methoxypropoxy, ethoxy Alkoxy substituted such as propoxy, n-propoxypropoxy, isopropoxybutoxy, n-propoxybutoxy; hydroxy C1-C4 alkoxy substituted such as 2-hydroxyethoxyethoxy; carboxymethoxy, 2-carboxyethoxy, 3-carboxypropoxy Carboxy-substituted ones such as 2-sulfoethoxy, 3-sulfopropoxy, 4-sulfobutoxy-substituted ones, and the like.

In the case where the ring substituted by R ⁵ to R ⁷ is a benzene ring in which no ring represented by a broken line exists, among the above, preferred R ⁵ to R ⁷ are a hydrogen atom, an unsubstituted C1-C4 alkyl group An unsubstituted C1-C4 alkoxy group, a hydroxy-substituted C1-C4 alkoxy group, a sulfo-substituted C1-C4 alkoxy group, a carboxy-substituted C1-C4 alkoxy group, and an acetylamino group, more preferably a hydrogen atom, an unsubstituted C1- Examples thereof include a C4 alkyl group and a sulfo-substituted C1-C4 alkoxy group.
As the combination of R ⁵ to R ^7, a combination in which any one is a hydrogen atom and the remaining two are other than a hydrogen atom is preferable, and a combination in which R ⁶ is a hydrogen atom, and R ⁵ and R ⁷ are other than a hydrogen atom is more preferable. Preferably, R ⁵ is a sulfo-substituted C1-C4 alkoxy group or a carboxy-substituted C1-C4 alkoxy group, R ⁶ is a hydrogen atom, R ⁷ is an unsubstituted C1-C4 alkyl group, an unsubstituted C1-C4 alkoxy group, a carboxy-substituted C1- A combination in which a C4 alkoxy group or an acetylamino group is more preferable, and a combination in which R ⁵ is a sulfo-substituted C1-C4 alkoxy group, R ⁶ is a hydrogen atom, and R ⁷ is an unsubstituted C1-C4 alkyl group is particularly preferable.
Specific examples of particularly preferred combinations include a combination in which R ⁵ is a sulfo-substituted C2-C4 alkoxy group (most preferably 3-sulfopropoxy), R ⁶ is a hydrogen atom, and R ⁷ is methyl.

When the ring in which R ⁵ to R ⁷ are substituted is a naphthalene ring in which a ring represented by a broken line is present, preferable examples of R ⁵ to R ⁷ include a hydrogen atom and sulfo.
The combination of R ⁵ to R ⁷ is preferably a combination in which any two are hydrogen atoms and the remaining one is sulfo, R ⁵ is a hydrogen atom, one of R ⁶ and R ⁷ is a hydrogen atom, and the other is a sulfo group. A combination that is

In the above formula (1), the group A represents a substituted phenyl group or a substituted naphthyl group.

Among the substituents in the group A, examples of the benzenesulfonyloxy group in which the benzene ring is substituted with a methyl group, a nitro group, or a chlorine atom include methyl-substituted ones such as 4-toluenesulfonyloxy; 4-nitrobenzenesulfonyloxy and the like Nitro-substituted ones; those substituted with a chlorine atom such as 4-chlorobenzenesulfonyloxy; and the like.

Among the substituents in the group A, examples of the unsubstituted C1-C4 alkyl group include the same as the unsubstituted C1-C4 alkyl group in the above R ¹ , including preferable ones.

Among the substituents in the group A, examples of the unsubstituted C1-C4 alkoxy group include the same as the unsubstituted C1-C4 alkoxy group in R ⁵ to R ⁷ , including preferable ones.

Among the substituents in the group A, the C1-C4 alkoxy group substituted with a hydroxy group, an unsubstituted C1-C4 alkoxy group, a hydroxy C1-C4 alkoxy group, a sulfo group, or a carboxy group includes the above R ⁵ to R ⁷ , The corresponding substituted C1-C4 alkoxy group and the same including preferable ones are mentioned.

Among the substituents in the group A, examples of the unsubstituted C1-C4 alkylsulfonyl group include linear or branched ones, and linear ones are preferred. Specific examples thereof include linear ones such as methylsulfonyl, ethylsulfonyl, propylsulfonyl, and butylsulfonyl; branched ones such as isopropylsulfonyl and isobutylsulfonyl; and the like.

Among the substituents in the group A, the C1-C4 alkylsulfonyl group substituted with a hydroxy group, a sulfo group, or a carboxy group has the above-described substituents on any carbon atom in the unsubstituted C1-C4 alkylsulfonyl group. And the number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but it is preferably substituted at the end of the alkyl group.
Specific examples include hydroxy-substituted compounds such as hydroxyethylsulfonyl and 2-hydroxypropylsulfonyl; sulfo-substituted compounds such as 2-sulfoethylsulfonyl and 3-sulfopropylsulfonyl; 2-carboxyethylsulfonyl and 3-carboxypropylsulfonyl. Carboxy-substituted ones such as;

Among the substituents in the group A, examples of the unsubstituted C1-C8 alkylaminosulfonyl group include linear or branched ones, and linear ones are preferred. Specific examples include, for example, straight chain such as methylaminosulfonyl, ethylaminosulfonyl, propylaminosulfonyl, butylaminosulfonyl, pentylaminosulfonyl, hexylaminosulfonyl, octylaminosulfonyl, etc .; branched such as isopropylaminosulfonyl, isobutylaminosulfonyl A chain; and the like.

Among the substituents in the group A, the C1-C8 alkylaminosulfonyl group substituted with a hydroxy group, a sulfo group, or a carboxy group includes the above substituents on any carbon atom in the unsubstituted C1-C8 alkylaminosulfonyl group. The number of the substituents is usually 1 or 2, and preferably 1. The position of the substituent is not particularly limited, but it is preferably substituted at the end of the alkyl group. More preferred are C1-C6 substituted with the above group, and more preferred are C2-C4.
Specific examples include hydroxy-substituted C2-C4 such as hydroxyethylaminosulfonyl and 2-hydroxypropylaminosulfonyl; sulfo-substituted C2-C4 such as 2-sulfoethylaminosulfonyl and 3-sulfopropylaminosulfonyl; 2 -Carboxy-substituted C2-C4 such as carboxyethylaminosulfonyl, 3-carboxypropylaminosulfonyl and the like.

Among the substituents in the group A, examples of the unsubstituted C1-C8 alkylcarbonylamino group include straight-chain or branched-chain groups, and straight-chain is preferable.
Specific examples include unsubstituted straight chain such as acetylamino, propionylamino, butyrylamino, valerylamino, hexanoylamino, heptanoylamino, octanoylamino, nonanoylamino; isobutyrylamino, pivaloylamino, isovalerylamino And unsubstituted branched chain such as 2-ethylhexanoylamino; and the like.

Among the substituents in the group A, examples of the C1-C8 alkylcarbonylamino group substituted with a carboxy group include those having a carboxy group at any carbon atom in the unsubstituted C1-C8 alkylcarbonylamino group. The number of groups is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but it is preferably substituted at the end of the alkyl group. More preferred are C1-C6 substituted with the above group, and more preferred are C2-C4. Specific examples include 3-carboxypropionylamino, 4-carboxybutyrylamino and the like.

As the benzoylamino group in which the benzene ring is substituted with a sulfo group, a carboxy group, a chlorine atom or a C1-C4 alkyl group among the substituents in the group A, any carbon atom of the benzene ring of the unsubstituted benzoylamino group may be The number of the substituents is usually 1 or 3, and preferably 1 or 2. The position of the substituent is not particularly limited.
Specific examples include sulfo-substituted ones such as 2-sulfobenzoylamino; carboxy-substituted ones such as 2-carboxybenzoylamino and 2,5-dicarboxybenzoylamino; 2-chlorobenzoylamino, 3-chlorobenzoylamino, Examples include chlorine-substituted ones such as 4-chlorobenzoylamino; alkyl-substituted ones such as 3-methylbenzoylamino, 4-methylbenzoylamino, 4-ethylbenzoylamino, 4-propylbenzoylamino; and the like.

Among the substituents in the group A, the benzenesulfonylamino group in which the benzene ring is substituted with a methyl group, a nitro group, or a chlorine atom is the same as the above substituents on any carbon atom of the benzene ring of the unsubstituted benzenesulfonylamino group. The number of the substituents is usually 1 or 2, and preferably 1. The position of the substituent is not particularly limited, but is preferably substituted at the 4-position.
Specific examples include methyl-substituted ones such as 4-toluenesulfonylamino; nitro-substituted ones such as 4-nitrobenzenesulfonylamino; those substituted with a chlorine atom such as 4-chlorobenzenesulfonylamino; and the like.

When the group A is a substituted phenyl group, the number of the substituents is usually 1 to 4, preferably 1 to 3, more preferably 1 or 2, and still more preferably 2. The position of the substituent is not particularly limited. However, when the bonding position of the azo group is 1-position and the number of substituents is 1, it is 4-position; similarly, when 2-position, 2-position, 4-position, 3-position, 4-position, or 3 It is preferable that the position and the 5th position are the second position, the 4th position and the 5th position. When there are a plurality of substituents, the types of the substituents may be the same or different.
Preferred substituents when group A is a substituted phenyl group include carboxy, sulfo, chlorine, sulfamoyl, nitro, unsubstituted C1-C4 alkoxy, and carboxy among the substituents in group A. A substituted C1-C4 alkylsulfonyl group, an unsubstituted C1-C8 alkylcarbonylamino group, or an unsubstituted benzoylamino group.
Preferable specific examples include sulfo, carboxy, sulfamoyl, chlorine atom, acetylamino, nitro, benzoylamino, methoxy, or carboxyethylsulfonyl, more preferably sulfo or nitro.

When group A is a substituted naphthyl group, the bonding position of the azo group is 1-position or 2-position, and 2-position is preferred. The number of substituents is usually 1 to 4, preferably 2 or 3. The position of the substituent is not particularly limited, but preferred substituent positions are as follows.
When the bonding position of the azo group is 1-position, the number of substituents is 1, and the position of the substituent is preferably 4-position.
When the bonding position of the azo group is the 2-position and the number of substituents is 2, the position of the substituent is preferably 4-position and 6-position, or 4-position and 8-position, and similarly when the number of substituents is 3 The positions of the substituents are preferably 4-position, 6-position and 8-position; 4-position, 6-position and 9-position; or 1-position, 5-position and 7-position;
A preferable substituent when the group A is a substituted naphthyl group is a C1-C4 alkoxy group substituted with a sulfo group, an unsubstituted C1-C4 alkoxy group, a sulfo group or a carboxy group among the substituents in the group A. is there.
Preferable specific examples are sulfo, methoxy, sulfoethoxy, sulfopropoxy and carboxymethoxy, and sulfo is more preferable.

In the above formula (1), the group B represents a divalent substituted thiophene group or a divalent substituted thiazole group bonded to an azo group at the 2-position and 5-position, the latter being preferred.
When the group B is a divalent substituted thiophene group bonded to an azo group at the 2-position and 5-position (hereinafter simply referred to as “divalent substituted thiophene group”), the number of substituents is usually 1 or 2, preferably 2. When the thiophene group has two substituents, the types of the substituents may be the same or different.
When the group B is a divalent substituted thiazole group bonded to an azo group at the 2-position and 5-position (hereinafter simply referred to as “divalent substituted thiazole group”), the substitution that the thiazole group has The number of groups is one.

Examples of the unsubstituted C1-C4 alkyl group in the substituent of the group B include the same as the unsubstituted C1-C4 alkyl group in R ¹ , including preferable ones.

As a phenyl group in which the benzene ring in the substituent of the group B is substituted with a methyl group, a methoxy group, an acetylamino group, a nitro group, a sulfo group, a carboxy group, a cyano group, a carbamoyl group, a fluorine atom, a chlorine atom or a bromine atom Is a methyl-substituted one such as 3-tolyl or 4-tolyl; a methoxy-substituted one such as 3-methoxyphenyl or 4-methoxyphenyl; an acetyl such as 3- (acetylamino) phenyl or 4- (acetylamino) phenyl Amino-substituted, nitro-substituted such as 3-nitrophenyl and 4-nitrophenyl; sulfo-substituted such as 3-sulfophenyl and 4-sulfophenyl; carboxy-substituted such as 3-carboxyphenyl and 4-carboxyphenyl A cyano-substituted one such as 4-cyanophenyl; a carbamoyl such as 4-carbamoylphenyl 2-fluorophenyl; 4-fluorophenyl; fluorine atom substitution such as 2,4-difluorophenyl; 2-chlorophenyl; 4-chlorophenyl; chlorine atom substitution such as 2,4-dichlorophenyl; And those having a bromine atom substitution such as 4-bromophenyl;

Examples of the unsubstituted naphthyl group in the substituent of the group B include 1-naphthyl and 2-naphthyl.

As the naphthyl group in which the naphthalene ring in the substituent of the group B is substituted with a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group, or a sulfo-substituted C1-C4 alkoxy group, the above-mentioned unsubstituted naphthyl A group having these substituents is exemplified. The number of substituents is usually 1 to 4, preferably 1 or 2. The position of the substituent is not particularly limited, but when the bonding position with the group B is 1-position, 2-substituted 2-position and 3-position are preferable. Further, when the bonding position with the group B is the 2-position, a mono-substituted one at the 6-position or a 2-substituted one at the 5-position and the 6-position is preferable.
Specific examples include methyl-substituted ones such as 4-methyl-1-naphthyl; sulfo-substituted ones such as 6-sulfo-1-naphthyl and 8-sulfo-2-naphthyl; 2-methoxy-1-naphthyl, 2 -Ethoxy-1-naphthyl, 6-methoxy-2-naphthyl, 1-methoxy-2-naphthyl, 1-ethoxy-2-naphthyl, 1-propoxy-2-naphthyl, 1-butoxy-2-naphthyl, etc. C1-C4 alkoxy substituted; 2- (sulfoethoxy) -1-naphthyl, 2- (sulfopropoxy) -1-naphthyl, 1- (sulfopropoxy) -2-naphthyl, 1- (sulfobutoxy) -2- A sulfo-substituted C1-C4 alkoxy-substituted group such as naphthyl; a bromine atom such as 5-bromo-6-methoxy-2-naphthyl and an unsubstituted C1-C4 alkoxy group substituted Substituted by sulfo and unsubstituted C1-C4 alkoxy groups such as 5-sulfo-6-methoxy-2-naphthyl; carboxy and unsubstituted C1-C4 alkoxy groups such as 2-methoxy-3-carboxy-1-naphthyl; Are substituted; and the like.

Preferred substituents in the divalent substituted thiophene group include, among the substituents of the group B, a cyano group; a carbamoyl group; an unsubstituted phenyl group; and a benzene ring substituted with a methyl group, a methoxy group, or an acetylamino group. A phenyl group; an unsubstituted naphthyl group; an unsubstituted C1-C4 alkoxy group, or a naphthyl group substituted by an unsubstituted C1-C4 alkoxy group and a sulfo group;
Specific examples of preferred substituents include cyano, carbamoyl, unsubstituted phenyl, 4-tolyl, 3-methoxyphenyl, unsubstituted 2-naphthyl, 6-methoxy-2-naphthyl, 5-sulfo-6-methoxy-2- And naphthyl.

Preferred substituents in the substituted thiazole group include an unsubstituted phenyl group among the substituents of the group B; a phenyl group in which the benzene ring is substituted with a methyl group, a methoxy group, an acetylamino group, or a chlorine atom; an unsubstituted naphthyl group Or a naphthyl group substituted with an unsubstituted C1-C4 alkoxy group and a sulfo group.
Preferred examples include unsubstituted phenyl, 4-tolyl, 4-methoxyphenyl, 3- (acetylamino) phenyl, 3-chlorophenyl, unsubstituted 2-naphthyl, 5-sulfo-6-methoxy-2-naphthyl and the like. Can be mentioned.

Among the compounds represented by the above formula (1), preferred are the compounds represented by the above formula (2). In formula (2), R ¹ to R ⁷ , group A and group B have the same meaning as in formula (1), including preferred ones and specific examples.

In the above formula (1) or (2), in the group B, a divalent substituted thiophene group is preferably a group represented by the formula (3) and a divalent substituted thiazole group is a group represented by the formula (4). is there.

R ⁸ in the above formula (3) is a cyano group or a carbamoyl group, preferably cyano.

In formula (3), R ⁹ is a cyano group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; the benzene ring is a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group , A cyano group, a carbamoyl group, a phenyl group substituted with a fluorine atom, a chlorine atom or a bromine atom; an unsubstituted naphthyl group; and a naphthalene ring is a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group A group or a naphthyl group substituted with a sulfo-substituted C1-C4 alkoxy group;
^* 1 represents a bond to the azo group to which the group A is bonded, and ^* 2 represents a bond to the azo group to which the ring substituted by R ⁵ to R ⁷ is bonded.

In formula (3), examples of the unsubstituted C1-C4 alkyl group for R ⁹ include the same as the unsubstituted C1-C4 alkyl group for R ¹ above, including preferred ones.

In formula (3), phenyl in which the benzene ring in R ⁹ is substituted with a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group, carbamoyl group, fluorine atom, chlorine atom or bromine atom Examples of the group include the same groups as those in the substituent of the group B, including preferable groups.

In the formula (3), the naphthyl group in which the naphthalene ring in R ⁹ is substituted with a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group, or a sulfo-substituted C1-C4 alkoxy group, The same thing as a thing corresponding to the substituent of group B including a preferable thing is mentioned.

Preferred R ⁹ in the formula (3) is, among the above, an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; a benzene ring is a methyl group, an acetylamino group, a nitro group, a sulfo group, a carboxy group, or a chlorine atom. A substituted phenyl group; an unsubstituted naphthyl group; or a naphthyl group in which the naphthalene ring is substituted with an unsubstituted C1-C4 alkoxy group, a sulfo group, or a carboxy group.
R ⁹ is more preferably an unsubstituted phenyl group; a phenyl group in which a benzene ring is substituted with a methyl group, a methoxy group, an acetylamino group, or a chlorine atom; an unsubstituted naphthyl group; or a naphthalene ring in a methoxy group and / or A naphthyl group substituted by a sulfo group.

A preferred combination of R ⁸ and R ⁹ in formula (3) is a combination of R ⁸ is cyano and R ⁹ is phenyl, 4-tolyl, 4- (acetylamino) phenyl or 2-naphthyl.

In the above formula (4), R ¹⁰ is a cyano group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; the benzene ring is a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group Group, cyano group, carbamoyl group, phenyl group substituted by fluorine atom, chlorine atom or bromine atom; unsubstituted naphthyl group; and naphthalene ring is methyl group, bromine atom, carboxy group, sulfo group, unsubstituted C1-C4 Represents a group selected from the group consisting of an alkoxy group or a naphthyl group substituted with a sulfo-substituted C1-C4 alkoxy group;
^* 3 represents a bond to the azo group to which the group A is bonded, and ^* 4 represents a bond to the azo group to which the ring substituted by R ⁵ to R ⁷ is bonded.

In formula (4), examples of the unsubstituted C1-C4 alkyl group for R ¹⁰ include the same as the unsubstituted C1-C4 alkyl group for R ¹ , including preferred ones.

In formula (4), phenyl in which the benzene ring in R ¹⁰ is substituted with a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group, carbamoyl group, fluorine atom, chlorine atom or bromine atom Examples of the group include the same groups as those in the substituent of the group B, including preferable groups.

In formula (4), the naphthyl group in which the naphthalene ring in R ¹⁰ is substituted with a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group, or a sulfo-substituted C1-C4 alkoxy group, The same thing as a thing corresponding to the substituent of group B including a preferable thing is mentioned.

Preferred R ¹⁰ in the formula (4) is, among the above, an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; a benzene ring is a methyl group, an acetylamino group, a nitro group, a sulfo group, a carboxy group, or a chlorine atom. A substituted phenyl group; an unsubstituted naphthyl group; or a naphthyl group in which the naphthalene ring is substituted with a C1-C4 alkoxy group, a sulfo group, or a carboxy group.
R ¹⁰ is more preferably an unsubstituted phenyl group; a phenyl group in which a benzene ring is substituted with a methyl group, a methoxy group, an acetylamino group, or a chlorine atom; an unsubstituted naphthyl group; or a naphthalene ring in a methoxy group or a sulfo group A naphthyl group substituted with a group.
More preferred R ¹⁰ includes unsubstituted phenyl or 2-naphthyl, and particularly preferred is unsubstituted phenyl.

A preferable group A in the formula (1) is a group represented by the above formula (5) or the formula (6).

The benzenesulfonyloxy group in which the benzene ring in R ^{11 to} R ¹³ in the formula (5) or R ^{14 to} R ¹⁷ in the formula (6) is substituted with a methyl group, a nitro group or a chlorine atom is The same thing as the thing corresponding to a substituent and a preferable thing is mentioned.

Examples of the unsubstituted C1-C4 alkyl group in R ^{11 to} R ¹³ in formula (5) or R ^{14 to} R ¹⁷ in formula (6) include those corresponding to the substituents of the above group A and preferred ones. Are the same.

Examples of the unsubstituted C1-C4 alkoxy group in R ^{11 to} R ¹³ in formula (5) or R ^{14 to} R ¹⁷ in formula (6) include those corresponding to the substituents of the above group A and preferred ones. Are the same.

As the C1-C4 alkoxy group substituted with a hydroxy group, a C1-C4 alkoxy group, a sulfo group or a carboxy group in R ^{11 to} R ¹³ in the formula (5) or R ^{14 to} R ¹⁷ in the formula (6), The same thing as the thing corresponding to the substituent of the said group A including a preferable thing is mentioned.

As the unsubstituted C1-C4 alkylsulfonyl group in R ^{11 to} R ¹³ in the formula (5) or R ^{14 to} R ¹⁷ in the formula (6), those corresponding to the substituents of the group A and preferred ones are as follows. Including the same thing.

As the C1-C4 alkylsulfonyl group substituted with a hydroxy group, a sulfo group or a carboxy group in R ^{11 to} R ¹³ in formula (5) or R ^{14 to} R ¹⁷ in formula (6), the substitution of the above group A The same thing as the thing corresponding to a group and a preferable thing is mentioned.

As the unsubstituted C1-C8 alkylaminosulfonyl group in R ^{11 to} R ¹³ in formula (5) or R ^{14 to} R ¹⁷ in formula (6), those corresponding to the substituents of the above group A and preferable ones The same thing is mentioned including.

As the C1-C8 alkylaminosulfonyl group substituted with a hydroxy group, a sulfo group or a carboxy group in R ^{11 to} R ¹³ in formula (5) or R ^{14 to} R ¹⁷ in formula (6), The same thing as the thing corresponding to a substituent and a preferable thing is mentioned.

As the unsubstituted C1-C8 alkylcarbonylamino group in R ^{11 to} R ¹³ in the formula (5) or R ^{14 to} R ¹⁷ in the formula (6), those corresponding to the substituents of the above group A and preferable ones The same thing is mentioned including.

As the carboxy-substituted C1-C8 alkylcarbonylamino group in R ^{11 to} R ¹³ in the formula (5) or R ^{14 to} R ¹⁷ in the formula (6), those corresponding to the substituents of the above group A and preferable ones The same thing is mentioned including.

As the benzoylamino group in which the benzene ring in R ^{11 to} R ¹³ in formula (5) or R ^{14 to} R ¹⁷ in formula (6) is substituted with a sulfo group or a C1-C4 alkyl group, The same thing as the thing corresponding to a group and a preferable thing is mentioned.

The benzenesulfonylamino group in which the benzene ring in R ^{11 to} R ¹³ in formula (5) or R ^{14 to} R ¹⁷ in formula (6) is substituted with a methyl group, a nitro group or a chlorine atom is The same thing as the thing corresponding to a substituent and a preferable thing is mentioned.

Preferable R ^{11 to} R ¹³ in formula (5) are, among the above, substituted with a hydrogen atom, a carboxy group, a sulfo group, a chlorine atom, a sulfamoyl group, a nitro group, an unsubstituted C1-C4 alkoxy group, or a carboxy group. A C1-C4 alkylsulfonyl group, an unsubstituted C1-C8 alkylcarbonylamino group, or an unsubstituted benzoylamino group.
Preferable specific examples include a hydrogen atom, sulfo, carboxy, sulfamoyl, chlorine atom, acetylamino, nitro, benzoylamino, methoxy, or carboxyethylsulfonyl.

In the preferred combination of R ^{11 to} R ¹³ in the formula (5), R ¹¹ is a hydrogen atom, carboxy, or sulfo, R ¹² is a hydrogen atom, sulfo, chlorine atom, nitro, sulfamoyl, unsubstituted C1-C4 alkoxy group, non substituted C1-C8 alkylcarbonylamino group, or unsubstituted benzoylamino groups, R ¹³ is a hydrogen atom, a carboxyl, a combination of sulfo, among combinations of the above, one of the at least R ¹¹ to R ^13, or 2 More preferred are combinations in which one is a group independently selected from sulfo and carboxy.
In addition, when the substitution position of the azo group in the formula (5) is the first position, and two of R ^{11 to} R ¹³ are hydrogen atoms, the group other than the hydrogen atom is the fourth position; when one is a hydrogen atom, the hydrogen atom The groups other than atoms are preferably substituted at the 2-position, 4-position, 3-position, 4-position, 3-position and 5-position; when all of the groups are other than hydrogen atoms, they are preferably substituted at the 2-position, 4-position and 5-position, respectively. .

Preferable R ¹⁴ to R ¹⁷ in the formula (6) include a hydrogen atom, a sulfo group, an unsubstituted C1-C4 alkoxy group, a C1-C4 alkoxy group substituted with a sulfo group or a carboxy group.
Preferable specific examples include sulfo, methoxy, sulfoethoxy, sulfopropoxy, and carboxymethoxy, and more preferably a hydrogen atom and sulfo.

In the preferred combination of R ¹⁴ to R ¹⁷ in formula (6), R ¹⁴ is a sulfo or hydrogen atom, R ¹⁵ is a hydrogen atom, R ¹⁶ is a sulfo or hydrogen atom, and R ¹⁷ is a sulfo, more preferably R ¹⁴ is Sulfo, R ¹⁵ is a hydrogen atom, R ¹⁶ is a hydrogen atom, and R ¹⁷ is a combination of sulfo.
The substitution position from R ¹⁴ to R ¹⁷ is not particularly limited, but the substitution position of the azo group is the 2-position, R ¹⁴ is the 4-position, R ¹⁵ is the 1-position, R ¹⁶ is the 6-position, and R ¹⁷ is the 8-position. Substitution is preferred.

The compound which combined the preferable groups described about the various substituents of the said Formula (1) to (5) is more preferable, and what combined the more preferable groups is still more preferable. The same applies to a combination of more preferable groups. Moreover, about what described the preferable combination, it is the same also about the compound which combined the preferable combination.

Among the above combinations, R ¹ is an unsubstituted C1-C4 alkyl group, preferably a methyl group, R ² is a cyano group or a carbamoyl group, preferably a cyano group, R ³ is a hydrogen atom, R ⁴ is a sulfo group, R ⁵ Is a C1-C4 alkoxy group substituted with a sulfo group, preferably a sulfopropoxy group, R ⁶ is a hydrogen atom, R ⁷ is an unsubstituted C1-C4 alkyl group, preferably a methyl group, and the group A is represented by formula (6). R ¹⁴ is a 4-position sulfo group, R ¹⁵ and R ¹⁶ are hydrogen atoms, R ¹⁷ is an 8-position sulfo group, the group B is represented by the formula (4), and R ¹⁰ is a phenyl group Is particularly preferred.

The salt of the azo compound represented by the formula (1) is an inorganic or organic cation salt. Among them, specific examples of inorganic salts include alkali metal salts, alkaline earth metal salts, and ammonium salts. Preferred inorganic salts are lithium, sodium, potassium salts and ammonium salts, and organic cation salts. Examples of the salt include, but are not limited to, quaternary ammonium ions represented by the following formula (9). 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 (9), 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 Z ¹ , Z ² , Z ³ , and Z ⁴ alkyl groups in formula (9) include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and the like. Specific examples of the hydroxyalkyl group include hydroxy C1-C4 alkyl groups such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl and 2-hydroxybutyl. Examples of hydroxyalkoxyalkyl groups include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxy Butyl Hydroxy C1-C4 alkoxy C1-C4 alkyl group, and hydroxyethoxy C1-C4 alkyl are preferred among these. 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, hydroxy And hydroxyethoxy C1-C4 alkyl groups such as ethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl and the like. .

Specific examples of combinations of Z ¹ , Z ² , Z ³ , and Z ^{4 which} are preferable compounds as the formula (9) are shown in Table 1 below.

The azo compound represented by the above formula (1) can be synthesized, for example, by the following method. In addition, the structural formula of the compound in each step shall be expressed in the form of a free acid. In the following formulas (10) to (19), R ¹ to R ⁷ , group A and group B have the same meanings as described above. Have.
A compound represented by the following formula (10) is diazotized by a conventional method, and this is coupled with a compound represented by the following formula (11) by a conventional method to obtain a compound represented by the following formula (12). .

The compound represented by the formula (12) thus obtained is diazotized by a conventional method, and then this and a compound represented by the following formula (13) are subjected to a coupling reaction by a conventional method, which is represented by the following formula (14). To obtain a compound.

The compound represented by the formula (14) thus obtained is diazotized by a conventional method, and then this and a compound represented by the following formula (15) are subjected to a coupling reaction by a conventional method, whereby the above formula (1) The azo compound of this invention represented by these can be obtained.

The compound represented by the formula (15) can be synthesized according to the method described in Patent Document 4. The compound represented by the above formula (11) is synthesized according to the method described in JP-A-59-204186, East German Patent No. 159429, Journal of the American Chemical Society (1950) 72 3722-5, and the like. be able to.

Although it does not specifically limit as a suitable specific example of the azo compound of this invention represented by Formula (1), The compound shown by the structural formula given to the following Table 2 thru | or 4 etc. are mentioned.
In each table, functional groups such as a sulfo group and a carboxy group are described in the form of a free acid for convenience.

The diazotization of the compound represented by the formula (10) is carried out by a method known per se. For example, it is carried out in an inorganic acid medium using a nitrite, for example an alkali metal nitrite such as sodium nitrite, at a temperature of -5 to 30 ° C, preferably 0 to 15 ° C. Coupling of the diazotized compound of the compound represented by the formula (10) and the compound represented by the formula (11) 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 5 to 25 ° C, and at an acidic to neutral pH value, for example pH 1-6. Since the diazotization reaction solution is acidic and the reaction system is further acidified by the progress of the coupling reaction, it is preferable to adjust the pH value by adding a base. Examples of the base that can be used include alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate, acetates such as sodium acetate, ammonia, and organic amines. . The compound represented by formula (10) and the compound represented by formula (11) are used in approximately stoichiometric amounts.

The diazotization of the compound represented by the above formula (12) is carried out by a method known per se. For example, it is carried out using nitrosylsulfuric acid in sulfuric acid, phosphoric acid, acetic acid or propionic acid medium, for example at a temperature of -5 to 30 ° C, preferably 0 to 15 ° C. Coupling of the diazotized compound of the compound represented by formula (12) and the compound represented by formula (13) is also carried out under conditions known per se. It is carried out in water or an aqueous organic medium, for example at a temperature of -5 to 30 ° C, preferably 5 to 25 ° C. The compound represented by formula (12) and the compound represented by formula (13) are used in approximately stoichiometric amounts.

The diazotization of the compound represented by the formula (14) is also carried out by a method known per se. For example, it is carried out using a nitrite, for example an alkali metal nitrite such as sodium nitrite, in an inorganic acid medium, for example at a temperature of 0 to 40 ° C., preferably 0 to 30 ° C. Coupling of the diazotized compound of the compound represented by formula (14) and the compound represented by formula (15) 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 0 to 50 ° C., preferably 5 to 30 ° C., and at a slightly 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. As the base, the same ones as described above can be used. The compounds represented by formulas (14) and (15) are used in approximately stoichiometric amounts.

In order to make the azo compound represented by the formula (1) of the present invention into a desired salt, a desired inorganic salt or a quaternary ammonium salt is added to the reaction solution after the coupling reaction to salt out, or hydrochloric acid or the like. A mineral acid is added and isolated in the form of a free acid, which is washed with water, acidic water or an aqueous organic medium as necessary to remove inorganic salts, and then the desired inorganic or By adding an organic base corresponding to the quaternary ammonium salt to form a salt, a salt of the target azo compound can be obtained as 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 water-containing organic substances miscible with water, so-called organic solvents miscible with water, and specific examples include water-soluble organic solvents described later. Examples of inorganic salts include alkali metal salts such as lithium chloride, sodium chloride and potassium chloride; ammonium salts such as ammonium chloride and ammonium bromide. Examples of organic cation salts include the above-mentioned formula (9). And a halogen salt of a quaternary ammonium ion represented by: Examples of the inorganic base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide (ammonia water), or alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate. Examples of organic bases include, but are not limited to, organic amines such as quaternary ammoniums represented by the above formula (9) such as diethanolamine and triethanolamine. It is not something.

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.

A reaction liquid containing the azo compound of the present invention represented by the above formula (1), for example, a reaction liquid after completion of the final step in the synthesis reaction of the compound represented by the above formula (1), is the production of the ink composition. Can be used directly. However, it is first isolated by drying, eg spray drying, or salted out by adding inorganic salts such as sodium chloride, potassium chloride, calcium chloride, sodium sulfate, or minerals such as hydrochloric acid, sulfuric acid, nitric acid. Isolating the azo compound of the present invention by aciding out by adding an acid, or by aciding out a combination of salting-out and aciding-out as described above, and then using this to prepare an ink composition You can also. 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 contained, and the balance is a composition having water as a main medium. The ink composition of the present invention is further water-soluble for the purpose of adjusting viscosity; adjusting drying; adjusting permeability when recording on a recording material (including those having an ink receiving layer); For example, the organic solvent may be contained in an amount of 0 to 30% by mass, and the ink preparation agent may be contained in an amount of 0 to 10% by mass, for example. 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. The pH and surface tension of the ink composition of the present invention can be appropriately adjusted with a pH adjusting agent and a surfactant as described later.

The ink composition of the present invention comprises water or a water-soluble organic solvent (an organic solvent miscible with water) containing the azo compound represented by the formula (1) together with other toning dyes as necessary. And an ink preparation agent is added if necessary. For the purpose of adjusting a neutral black ink composition having no color, other toning dyes and the like may be appropriately added to the azo compound of the present invention. 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, black, etc. The other pigment | dye which has a hue is mentioned. 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 blending 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.
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 approximately 1% by mass or less with respect to the total weight 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 conventional method using a reverse osmosis membrane, or a dried product or wet cake of the azo compound of the present invention is mixed with alcohol such as methanol, preferably C1-C4 alcohol and water. The mixture may be suspended and purified in a mixed solvent, and the precipitate may be desalted by a method such as filtration separation and drying.

Specific examples of the water-soluble organic solvent that can be used in the preparation of the ink composition include C1-C4 alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, and tert-butanol; N, N A carboxylic acid amide such as dimethylformamide or N, N-dimethylacetamide; a lactam such as 2-pyrrolidone, hydroxyethyl-2-pyrrolidone, N-methyl-2-pyrrolidone or N-methylpyrrolidin-2-one; -Cyclic ureas such as dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido-2-one; ketones or keto such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one Alcohol; tetrahydrofuran, dioxane, etc. Cyclic ether; ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene Mono-, oligo- or polyalkylene glycols or thioglycols having C2-C6 alkylene units such as glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol or dithiodiglycol; trimethylolpropane, glycerin or hexane-1,2 Polyol (triol) such as 1,6-triol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl Ether, diethylene glycol monoethyl ether, diethylene glycol C1-C4 alkyl ethers of polyhydric alcohols monobutyl ether (butyl carbitol) Triethylene glycol monomethyl ether or triethylene glycol monoethyl ether; .gamma.-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.

Examples of ink preparations that are appropriately used in the preparation of the ink composition include antiseptic / antifungal agents, pH adjusters, chelating reagents, rust inhibitors, water-soluble ultraviolet absorbers, water-soluble polymer compounds, dye solubilizers, and antioxidants. Agents and / or surfactants. These drugs are described below.

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.

Specific examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate or dicyclohexylammonium nitrite.

Examples of water-soluble UV absorbers include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

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

Specific examples of the dye solubilizer include ε-caprolactam, ethylene carbonate, urea, and the like.
As examples of the antioxidant, for example, various organic and metal complex anti-fading 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 their salts, N-acyl methyl taurates, alkyl sulfates Salt polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl sulfonate , Diethylsulfosuccinate, diethylhexylsylsulfosuccinate, dioctylsulfosuccinate and the like.
Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.
Specific examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, or Examples include imidazoline derivatives.
Specific examples of nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether and the like. Ether type, polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, poly Esters such as oxyethylene stearate, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-o Acetylene glycol (alcohol) series such as tin-3,6-diol and 3,5-dimethyl-1-hexyn-3-ol (for example, trade name Surfinol 104, 105, 82, 465, manufactured by Nissin Chemical Co., Ltd.) Orphine STG), polyglycol ether type (eg, Tergitol 15-S-7 manufactured by SIGMA-ALDRICH) and the like.
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 size of the filter for performing microfiltration is usually 1 to 0.1 microns, preferably 0.8 to 0.1 microns.

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

Next, the ink jet recording method of the present invention will be described. 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 and discharges the ink using the radiation pressure; a thermal ink jet (bubble jet (registered trademark)) method that uses the pressure generated by heating the ink to form bubbles; Etc. can be used.

The colored product of the present invention is colored by the azo compound of the present invention represented by the formula (1) or an ink composition containing the same, and preferably by an inkjet recording method using an inkjet printer. It is a substance colored by the ink composition containing the compound represented by the formula (1).
There are no particular restrictions on the substances that can be colored, but examples include information transmission sheets such as paper and film, fibers and fabrics (cellulose, nylon, wool, etc.), leather, and color filter base materials. Sheets are preferred.
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 by using a porous white inorganic substance capable of absorbing a pigment in ink such as porous silica, alumina sol or special ceramics, polyvinyl alcohol or polyvinyl Application to the surface of the substrate together with a hydrophilic polymer such as pyrrolidone;
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. Commercially available products such as a company-made product name, Advanced Photo Paper, Premium Plus Photo Paper, Premium Glossy Film or Photo Paper; 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 material on the surface is particularly prone to discoloration by ozone gas. However, since the ink composition of the present invention has excellent ozone gas resistance, it exhibits a particularly great effect when ink-jet recording is performed on such a recording material.

In order to record on a recording material such as an information transmission sheet by the ink jet recording method of the present invention, for example, a container containing the above ink composition is set at a predetermined position of an ink jet printer, and the recording material is processed by a normal method. Can be recorded.
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) and red (or orange) as necessary, as described above. These ink compositions of the respective colors can also be used in combination.
The ink composition of each color is poured into each container, and each container is set at a predetermined position of the ink jet printer in the same manner as the container containing the black ink composition of the present invention, and used for ink jet recording.

The azo compound of the present invention is a black pigment and has characteristics such as excellent water solubility, easy synthesis, and low cost. In addition, the high-concentration aqueous solution and ink composition containing this dye have good storage stability because they do not cause solid precipitation, change in physical properties, change in hue, etc. even when stored for a long period of time. The ink composition of the present invention is an aqueous black ink composition.
Further, a recorded image using an ink composition containing the compound has a very high printing density, and does not cause bronzing even when a high-concentration solution is recorded on photographic quality inkjet paper.
In addition, since it has a feature of low saturation, it exhibits an achromatic and high-quality hue that is more preferable as black.
In addition, the recording image has excellent durability such as light resistance, gas resistance, moisture resistance, water resistance, etc., particularly ozone gas resistance and light resistance.
Further, when used in combination with ink compositions containing magenta, cyan and yellow dyes, full-color ink jet recording with excellent fastness and storage stability is possible.
The ink composition containing the coloring matter of the present invention can be used for inkjet recording and writing instruments, and is particularly suitable for inkjet recording applications for the reasons described above.

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.
In addition, the operations such as each synthesis reaction and crystallization were performed under stirring unless otherwise specified.
In the following formulas, functional groups such as sulfo and carboxy are expressed in the form of free acid.
Moreover, both the pH value and reaction temperature described below show 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 was described in the examples for the measured compound.
The synthesized azo compound of the present invention showed a solubility of 100 g / L or more.

Example 1
(1)
Under stirring, 10.0 parts of phenacyl bromide and 3.8 parts of thiourea were added to 25 parts of ethanol. The solution was heated and stirred for 3 hours while refluxing ethanol. After cooling to room temperature, 20 parts of 2-propanol and 10 parts of water were added, and the precipitated solid was separated by filtration. This solid was washed with 15 parts of 2-propanol and dried to obtain 11.5 parts of a solid containing a hydrobromide salt of a compound represented by the following formula (16).

(2)
Under stirring, 9.2 parts of 7-aminonaphthalene-1,5-disulfonic acid was added to 50 parts of water. Add 7.8 parts of 35% hydrochloric acid, cool to 0-5 ° C in an ice bath, add 4.5 parts of 40% aqueous sodium nitrite solution at the same temperature, and stir at the same temperature for 1 hour to diazo reaction liquid. Got.
On the other hand, 3.4 parts of a solid containing the compound represented by the formula (16) obtained in Example 1 (1) was added to 50 parts of water and dispersed by stirring for 1 hour. A solution obtained by adding 0.2 part of sulfamic acid to the above diazo reaction solution and stirring for about 5 minutes was added dropwise at a reaction temperature of 15 to 25 ° C. for about 30 minutes.
After completion of dropping, sodium acetate was added to adjust the reaction solution to pH 1.8 to 2.2 and stirred for 2 hours. Thereafter, sodium acetate was further added to adjust pH to 6.0 to 7.0 and stirred for 2 hours. . The precipitated solid was separated by filtration, and the obtained solid was washed with 40 parts of 2-propanol and then dissolved in 50 parts of water. 7.0 parts of lithium chloride was added, and the precipitated solid was separated by filtration and dried to obtain 6.2 parts of a solid containing a monoazo compound represented by the following formula (17).

(3)
Under stirring, 3.1 parts of the solid containing the monoazo compound obtained in Example 1 (2) above was mixed with 20 parts of water in 108 parts of 85% phosphoric acid, 30 parts of acetic acid and 1.6 parts of 40% nitrosylsulfuric acid. The solution suspended in the part was added dropwise at 0 to 5 ° C. over about 20 minutes. After dropping, the mixture was stirred at the same temperature for 1 hour, and 0.3 part of 40% nitrosylsulfuric acid was added. Further, the mixture was stirred at the same temperature for 1 hour to obtain a diazo reaction liquid.
Meanwhile, 1.1 parts of a compound represented by the following formula (18) obtained by the method described in JP-A-2004-083492, 0.3 part of sulfamic acid and sodium hydroxide are added to 50 parts of water, and the pH is 4.5. An aqueous solution was obtained as ˜5.5. To this aqueous solution, the diazo reaction liquid obtained as described above was added dropwise at 5 to 10 ° C. over 1 hour. After the dropwise addition, the mixture was stirred at the same temperature for 1.5 hours, and then added dropwise while maintaining a 25% aqueous sodium hydroxide solution at 10 to 15 ° C. to adjust the pH to 4.5 to 5.0. Sodium chloride was added to the reaction solution for salting out, and the precipitated solid was separated by filtration to obtain a wet cake. The obtained wet cake was dissolved in 60 parts of water, 220 parts of 2-propanol was added, and the precipitated solid was separated by filtration, whereby 6.5 parts of a wet cake containing a disazo compound represented by the following formula (19) Got.

(4)
6.5 parts of a wet cake containing a disazo compound represented by the formula (19) obtained in Example 1 (3) above was added to 60 parts of water to obtain a solution. To this, 1.1 parts of 35% hydrochloric acid and 0.4 parts of 40% sodium nitrite aqueous solution were added at 0 to 5 ° C. and stirred at the same temperature for 30 minutes to obtain a diazo reaction liquid.
On the other hand, an aqueous solution having a pH of 7.5 to 8.5 was obtained by adding 0.6 part of a compound represented by the following formula (20) obtained by the method described in Patent Document 7 and sodium hydroxide to 20 parts of water. . The diazo reaction liquid obtained as described above was added dropwise to this aqueous solution at 10 to 20 ° C. for about 30 minutes. During the addition, the pH of the solution was maintained at 7.0 to 8.0 by adding sodium carbonate. After completion of dropping, the mixture was stirred at the same temperature for 1.5 hours, and 70 parts of 2-propanol was added. The precipitated solid was separated by filtration, the obtained wet cake was again dissolved in 40 parts of water, 50 parts of 2-propanol was added, the precipitated solid was separated by filtration, and dried to obtain the following formula (21 ) Was obtained as a sodium salt.
λmax: 608 nm.

Example 2
(A) Preparation of ink After obtaining the black ink composition of the present invention by mixing the components shown in Table 8 below, the contaminants were separated by filtration with a 0.45 μm membrane filter. Ink was prepared. This ink preparation is referred to as Example 2.
The water used for preparing the ink was ion exchange water. At the time of ink preparation, the pH of the ink was adjusted to pH 7-9 with sodium hydroxide, and ion exchange water was added to make the total amount 100 parts.

Table 8
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 (Product name: Surfinol 104, manufactured by Nissin Chemical)
Water + sodium hydroxide 77.4 parts Total 100.0 parts

The ink composition of the present invention and the ink obtained by microfiltration of the ink composition did not cause precipitation separation during storage, and did not change physical properties even after long-term storage.

Comparative Example 1
A comparative ink was prepared in the same manner as in Example 2 except that the dye of the following formula (22) disclosed in Example 1-2 of Patent Document 1 was used instead of the compound obtained in Example 1. did. The preparation of this comparative ink is referred to as Comparative Example 1.

Comparative Example 2
A comparative ink was prepared in the same manner as in Example 2 except that the dye of the following formula (23) disclosed in Example 2-6 of Patent Document 6 was used instead of the compound obtained in Example 1. did. This ink preparation is referred to as Comparative Example 2.

(B) Inkjet recording Using ink obtained as described above, Canon ink jet printer, product name PIXUS iP4100, glossy paper 1 (manufactured by EPSON, product name: photographic paper Krispia (high gloss)), Inkjet recording was performed on two types of information recording sheets (inkjet dedicated paper) of glossy paper 2 (manufactured by Hewlett-Packard Company, trade name: Advanced Photo Paper).
At the time of recording, an image pattern was prepared so that the reflection density was obtained in several gradations, a black recorded matter was obtained, and the following evaluation test was carried out using this as a test piece.

(C) Evaluation of recorded image Each test piece obtained using the ink prepared in Example 2 and each comparative example was subjected to color evaluation, and further, images of the image before and after the test for each of light resistance and ozone gas resistance were evaluated. The color difference ΔE was evaluated.
The color difference ΔE of the recorded image is a gradation portion in which the black reflection density Dk value of the recorded image before the test is in the range of 1.1 to 1.3 using a colorimeter manufactured by GRETAG-MACBETH, trade name: SpectroEye Was measured by measuring the color. The reflection density was measured using DIN as a density reference and a viewing angle of 2 degrees.
Each evaluation was performed on both glossy papers 1 and 2.
The specific test method is as follows. The evaluation test results are shown in Table 9 below.

1) Evaluation of color For the gradation portion in which the black reflection density Dk value of the recorded image in each test piece is in the range of 1.1 to 1.3, the CIE a * value and b are respectively measured using the above colorimeter. * The value was measured. The saturation C * value was calculated from the obtained a * value and b * value using the following formula. In the measurement of the a * value and the b * value, D65 was used as the light source and the viewing angle was 2 degrees.

C * = (a * ² + b * ² ) ^1/2

The color was evaluated according to the following criteria. As black ink, the near saturation is better.
○: C * is less than 30 △: C * is 30 or more and less than 40 ×: C * is 40 or more

2) Light resistance test Suga Test Instruments Co., Ltd., trade name: Each test piece was placed on a low-temperature xenon weatherometer XL75, and irradiated for 168 hours under conditions of 100,000 Lux illuminance, humidity 60% RH, and temperature 24 ° C. went. The CIE L * value, a * value, and b * value were measured for the recorded images of each test piece before and after exposure to xenon light, and the color difference ΔE was calculated using the following equation. The light source and the viewing angle at the time of measurement are the same as described above.

ΔE = [(ΔL *) ² + (Δa *) ² + (Δb *) ² ] ^1/2

In the above formula, ΔL *, Δa *, and Δb * mean the following values.
ΔL *: Difference in L * value before and after exposure Δa *: Difference in a * value before and after exposure Δb *: Difference in b * value before and after exposure

The test results were evaluated according to the following criteria.
○: ΔE is less than 20 Δ: ΔE is 20 or more and less than 30 ×: ΔE is 30 or more

3) Ozone gas resistance test, manufactured by Suga Test Instruments Co., Ltd., trade name Each test piece was placed in an ozone weatherometer, and left for 8 hours under the conditions of ozone concentration of 40 ppm, humidity of 60% RH, and temperature of 24 ° C. The CIE L * value, a * value, and b * value were measured for the recorded images of each test piece before and after ozone exposure, and the color difference ΔE was calculated. The calculation formulas for the light source, viewing angle, and ΔE at the time of measurement are the same as those in 2) Light resistance test.

The test results were evaluated according to the following criteria.
○: ΔE is less than 20 Δ: ΔE is 20 or more and less than 30 ×: ΔE is 30 or more

Table 9
Ozone gas resistance Light resistance Color Example 2
Glossy paper 1 ○ ○ ○
Glossy paper 2 ○ ○ ○
Comparative Example 1
Glossy paper 1 × × ○
Glossy paper 2 × × ○
Comparative Example 2
Glossy paper 1 ○ ○ ×
Glossy paper 2 ○ ○ ×

As is clear from the results in Table 6, each example showed results superior to Comparative Example 1 in ozone gas resistance and light resistance. Further, in the color evaluation, it was revealed that Example 2 has a saturation closer to 0 than Comparative Example 2 and an achromatic and high-quality black color than Comparative Example 2.
Therefore, it was confirmed that the recorded image obtained by the ink containing the azo compound of the present invention has excellent ozone gas resistance and light resistance, and has an achromatic and high-quality black hue that is more preferable as black, The azo compound of the present invention and the ink composition containing the azo compound are extremely useful for recording, particularly for inkjet recording.

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

Claims (19)

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

[In Formula (1),
R ¹ represents an unsubstituted C1-C4 alkyl group; a carboxy-substituted C1-C4 alkyl group; an unsubstituted phenyl group; a sulfo-substituted phenyl 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 represent a hydrogen atom; a methyl group; a chlorine atom; or a sulfo group;
The ring in which R ⁵ to R ⁷ are substituted represents a benzene ring when a ring represented by a broken line is not present; or a naphthalene ring when a ring represented by a broken line is present;
R ⁵ to R ⁷ are each independently a hydrogen atom; carboxy group; sulfo group; hydroxy group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; hydroxy group, unsubstituted C1-C4 alkoxy group, hydroxy A C1-C4 alkoxy group substituted with a C1-C4 alkoxy group, a sulfo group or a carboxy group; an acetylamino group;
Group A is a substituted phenyl group or a substituted naphthyl group,
The substituent of the group A includes a carboxy group; a sulfo group; a hydroxy group; an unsubstituted benzenesulfonyloxy group; a benzenesulfonyloxy group in which the benzene ring is substituted with a methyl group, a nitro group or a chlorine atom; a chlorine atom; a cyano group; Nitro group; sulfamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; C1-C4 alkoxy group substituted by hydroxy group, unsubstituted C1-C4 alkoxy group, sulfo group or carboxy group; unsubstituted A C1-C4 alkylsulfonyl group; a C1-C4 alkylsulfonyl group substituted with a hydroxy group, a sulfo group or a carboxy group; an unsubstituted C1-C8 alkylaminosulfonyl group; a C1-substituted with a hydroxy group, a sulfo group or a carboxy group; C8 alkylaminosulfonyl group; unsubstituted C1-C8 alkylcarbonyl Carboxy-substituted C1-C8 alkylcarbonylamino group; unsubstituted benzoylamino group; benzoylamino group in which the benzene ring is substituted with a sulfo group, a carboxy group, a chlorine atom or a C1-C4 alkyl group; an unsubstituted benzenesulfonylamino group A benzenesulfonylamino group in which the benzene ring is substituted with a methyl group, a nitro group or a chlorine atom; a trifluoromethyl group; an acetyl group; and a benzoyl group; a group selected from the group consisting of:
Group B is a divalent substituted thiophene group or a divalent substituted thiazole group bonded to an azo group at the 2-position and 5-position,
The substituent of the group B is cyano group; carbamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted phenyl group; benzene ring is methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group Group, carbamoyl group, phenyl group substituted with fluorine atom, chlorine atom or bromine atom; unsubstituted naphthyl group; and naphthalene ring is methyl group, bromine atom, carboxy group, sulfo group, unsubstituted C1-C4 alkoxy group, Or a naphthyl group substituted with a sulfo-substituted C1-C4 alkoxy group; a group selected from the group consisting of: ]. The azo compound or a salt thereof according to claim 1 represented by the following formula (2):

[In Formula (2),
R ¹ to R ⁷ , group A and group B have the same meaning as in formula (1). ]. The azo compound or a salt thereof according to claim 1 or 2, wherein the group B is represented by the following formula (3) or (4):

[In Formula (3),
R ⁸ represents a cyano group or a carbamoyl group,
R ⁹ is a cyano group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; the benzene ring is a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group, carbamoyl group A phenyl group substituted with a fluorine atom, a chlorine atom or a bromine atom; an unsubstituted naphthyl group; and a naphthalene ring is a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group, or a sulfo-substituted C1 A naphthyl group substituted with a -C4 alkoxy group; represents a group selected from the group consisting of:
^* 1 represents a bond with the azo group to which the group A is bonded,
^* 2 represents a bond to the azo group to which the ring substituted by R ⁵ to R ⁷ is bonded. ],

[In Formula (4),
R ¹⁰ is a cyano group; a carbamoyl group; an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; the benzene ring is a methyl group, methoxy group, acetylamino group, nitro group, sulfo group, carboxy group, cyano group, carbamoyl group A phenyl group substituted with a fluorine atom, a chlorine atom or a bromine atom; an unsubstituted naphthyl group; and a naphthalene ring is a methyl group, a bromine atom, a carboxy group, a sulfo group, an unsubstituted C1-C4 alkoxy group, or a sulfo-substituted C1 A naphthyl group substituted with a -C4 alkoxy group; represents a group selected from the group consisting of:
^* 3 represents a bond with the azo group to which the group A is bonded,
^{* 4,} a bond to the azo group ring from R ⁵ R ⁷ is substituted are attached represent respectively. ]. Group B is represented by formula (3), and in formula (3):
R ⁸ is a cyano group or a carbamoyl group,
R ⁹ is an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; a phenyl group in which the benzene ring is substituted with a methyl group, an acetylamino group, a nitro group, a sulfo group, a carboxy group, or a chlorine atom; an unsubstituted naphthyl group; Or a naphthyl group in which the naphthalene ring is substituted with an unsubstituted C1-C4 alkoxy group, a sulfo group or a carboxy group;
Or
Group B is represented by formula (4), and in formula (4):
R ¹⁰ is an unsubstituted C1-C4 alkyl group; an unsubstituted phenyl group; a phenyl group in which the benzene ring is substituted with a methyl group, an acetylamino group, a nitro group, a sulfo group, a carboxy group, or a chlorine atom; an unsubstituted naphthyl group; Or a naphthyl group in which the naphthalene ring is substituted with an unsubstituted C1-C4 alkoxy group, a sulfo group or a carboxy group;
The azo compound or a salt thereof according to any one of claims 1 to 3. The azo compound or a salt thereof according to any one of claims 1 to 4, wherein the group A is represented by the following formula (5) or (6):

[In Formula (5),
R ^{11 to} R ¹³ are each independently a hydrogen atom; a carboxy group; a sulfo group; a hydroxy group; an unsubstituted benzenesulfonyloxy group; a benzenesulfonyloxy group in which the benzene ring is substituted with a methyl group, a nitro group or a chlorine atom; Cyano group; nitro group; sulfamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; C1-C4 alkoxy group substituted with a hydroxy group, a C1-C4 alkoxy group, a sulfo group or a carboxy group Unsubstituted C1-C4 alkylsulfonyl group; C1-C4 alkylsulfonyl group substituted with a hydroxy group, sulfo group or carboxy group; unsubstituted C1-C8 alkylaminosulfonyl group; substituted with a hydroxy group, sulfo group or carboxy group; A C1-C8 alkylaminosulfonyl group; unsubstituted C1-C8 Carboxy-substituted C1-C8 alkylcarbonylamino group; unsubstituted benzoylamino group; benzoylamino group in which the benzene ring is substituted with a sulfo group or an unsubstituted C1-C4 alkyl group; unsubstituted benzenesulfonylamino group; benzene A benzenesulfonylamino group in which the ring is substituted with a methyl group, a nitro group or a chlorine atom; a trifluoromethyl group; an acetyl group; or a benzoyl group. ],

[In Formula (6),
R ^{14 to} R ¹⁷ are each independently a hydrogen atom; a carboxy group; a sulfo group; a hydroxy group; an unsubstituted benzenesulfonyloxy group; a benzenesulfonyloxy group in which the benzene ring is substituted with a methyl group, a nitro group, or a chlorine atom; Cyano group; nitro group; sulfamoyl group; unsubstituted C1-C4 alkyl group; unsubstituted C1-C4 alkoxy group; C1-C4 alkoxy group substituted with a hydroxy group, a C1-C4 alkoxy group, a sulfo group or a carboxy group Unsubstituted C1-C4 alkylsulfonyl group; C1-C4 alkylsulfonyl group substituted with a hydroxy group, sulfo group or carboxy group; unsubstituted C1-C8 alkylaminosulfonyl group; substituted with a hydroxy group, sulfo group or carboxy group; A C1-C8 alkylaminosulfonyl group; unsubstituted C1-C8 Carboxy-substituted C1-C8 alkylcarbonylamino group; unsubstituted benzoylamino group; benzoylamino group in which the benzene ring is substituted with a sulfo group or an unsubstituted C1-C4 alkyl group; unsubstituted benzenesulfonylamino group; benzene A benzenesulfonylamino group in which the ring is substituted with a methyl group, a nitro group or a chlorine atom; a trifluoromethyl group; an acetyl group; or a benzoyl group. ]. A group B represented by the formula (3), R ⁸ is a cyano group or a carbamoyl group, R ⁹ is an unsubstituted phenyl group; The azo compound or a salt thereof according to any one of claims 3 to 5, which is an unsubstituted naphthyl group; or a naphthyl group in which a naphthalene ring is substituted with a methoxy group or a sulfo group. A group B represented by the formula (4), R ¹⁰ is an unsubstituted phenyl group; a phenyl group in which the benzene ring is substituted with a methyl group, a methoxy group, an acetylamino group, or a chlorine atom; an unsubstituted naphthyl group; or naphthalene The azo compound or a salt thereof according to any one of claims 3 to 5, wherein the ring is a methoxy group or a naphthyl group substituted with a sulfo group. Group A is represented by Formula (5), and R ^{11 to} R ¹³ are each independently a hydrogen atom, a sulfo group, a carboxy group, a sulfamoyl group, a chlorine atom, an acetylamino group, a nitro group, a benzoylamino group, a methoxy group, Or an azo compound or a salt thereof according to any one of claims 1 to 7, which is a carboxyethylsulfonyl group. Group A is represented by Formula (6), R ¹⁴ ~R ¹⁷ is a hydrogen atom, a sulfo group, a methoxy group, carboxymethoxy group, a sulfo ethoxy group, any one of claims 1 to 7 is a sulfopropoxy group Or an azo compound thereof. 10. The azo compound according to claim 2, wherein R ⁵ is a C1-C4 alkoxy group substituted with a sulfo group, R ⁶ is a hydrogen atom, and R ⁷ is an unsubstituted C1-C4 alkyl group. salt. The azo compound or a salt thereof according to any one of claims 1 to 10, wherein R ¹ is a methyl group, R ² is a cyano group or a carbamoyl group, R ³ is a hydrogen atom, and R ⁴ is a sulfo group. The group B is represented by the formula (4), R ¹⁰ is a phenyl group or a 2-naphthyl group, 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 sulfo group, R The azo compound or a salt thereof according to any one of claims 3 to 5 and 7 to 11, wherein ⁵ is a sulfopropoxy group, R ⁶ is a hydrogen atom, and R ⁷ is a methyl group. The group A is represented by the formula (6), at least two of R ¹⁴ , R ¹⁶ and R ¹⁷ are sulfo groups, and R ¹⁵ is a hydrogen atom. The azo compound or a salt thereof according to Item. An ink composition comprising at least one azo compound or salt thereof according to any one of claims 1 to 13 as a coloring matter. An ink jet recording method for recording on a recording material by using the ink composition according to claim 14 as ink and discharging ink droplets of the ink according to a recording signal. The inkjet recording method according to claim 15, wherein the recording material is an information transmission sheet. 17. The ink jet recording method according to claim 16, 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 14. A colored body colored with the azo compound or a salt thereof according to any one of claims 1 to 13.