JP4632770B2 - Azo compound, ink composition, recording method and colored body - Google Patents

Description

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

A recording method using an inkjet printer, which is one of the representative methods among various color recording methods, generates ink droplets and attaches them to various recording materials (paper, film, fabric, etc.) for recording. Is. This method has been spreading rapidly in recent years due to the fact that the recording head and the recording material are not in direct contact, so there is little noise and quietness, and it is easy to reduce the size and speed. Expected. Conventionally, as inks for fountain pens, felt pens, and inks for ink jet recording, water-based inks in which water-soluble dyes are dissolved in an aqueous medium have been used. In order to prevent clogging of ink, a water-soluble organic solvent is generally added. With these conventional 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 stable storage. The water-soluble dyes that are required to have excellent properties and the like are required to have particularly high solubility in water and high solubility in water-soluble organic solvents added to the ink. Further, the formed image is required to have image fastness such as water resistance, light resistance, ozone gas resistance and moisture resistance.

Among these, ozone gas resistance refers to resistance to a phenomenon in which ozone gas having an oxidizing action present in the air acts on the dye in the recording paper and discolors the printed image. In addition to ozone gas, examples of the oxidizing gas having this kind of action include NOx, SOx, etc. Among these oxidizing gases, ozone gas is a main causative substance that further promotes the discoloration and discoloration phenomenon of inkjet recording images. It is said that. Ink-receiving layers provided on the surface of photographic image-dedicated inkjet paper often use materials such as porous white inorganic materials to accelerate ink drying and reduce bleeding at high image quality. Discoloration due to ozone gas is noticeable on a fresh recording paper. Since the discoloration phenomenon due to the oxidizing gas is characteristic of ink jet images, the improvement of ozone gas resistance is one of the most important issues in the ink jet recording method.

In the future, in order to expand the field of use of printing methods using ink, the ink composition used for inkjet recording and the colored bodies colored thereby will be further improved in light resistance, ozone gas resistance, moisture resistance and water resistance. There is a strong demand for improvement.

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 dyes for these black inks have been proposed to date, but they have not yet been able to provide products that fully satisfy market demands. Many of the proposed dyes are azo dyes, of which C.I. I. For disazo dyes such as Food Black 2, the hue is too shallow (reddish black), the color rendering (the property that the hue changes depending on the light source) is large, the optical density of the image is low, and the water resistance and moisture resistance are poor. There are problems such as insufficient gas resistance. In general, polyazo dyes having a conjugated system have problems such as low water solubility and easy occurrence of a bronzing phenomenon in which a recorded image has a partial metallic luster, and insufficient gas resistance. As for bronzing, in order to increase the optical density in black ink, the pigment content in the ink is often designed to be high, and there is a problem that bronzing is likely to occur. For example, in the case of film glossy paper with a thin ink receiving layer, It is especially likely to occur because of its low absorbency. Similarly, many azo metal-containing dyes that have been proposed have problems such as being unfavorable for biological safety and environmental problems because they contain metal ions, and extremely low ozone gas resistance.

As a compound (pigment) for black ink for ink jet which has been improved with respect to ozone gas resistance, which has become the most important issue in recent years, for example, compounds described in Patent Document 1 can be mentioned. However, the ozone gas resistance of these compounds does not fully meet market requirements. Further, as a compound structurally similar to the dye compound for black ink of the present invention, H acid (4-amino-5-naphthol-2,7-disulfonic acid) or K acid (4-amino-5-naphthol-1) is used. , 7-disulfonic acid) and γ-acid (6-amino-4-naphthol-2-sulfonic acid) or J acid (7-amino-4-naphthol-2-sulfonic acid) residue are azo-bonded to the amino group side. The compounds described in Patent Documents 2 and 3 in which a phenyl group or a naphthyl group derivative is azo-bonded to the hydroxyl group side can be mentioned, but those that sufficiently satisfy market requirements, particularly ozone gas resistance requirements. Absent.

JP 2003-183545 A JP 62-109872 A JP 2003-201412 A

The present invention has high solubility in a medium containing water as a main component, is stable even when a high-concentration aqueous solution and ink are stored for a long period of time, has a high density of printed images, and is highly concentrated on photographic quality inkjet paper. Even when printing a solution, it does not cause bronzing of the image, gives a printed black image with excellent fastness, especially ozone gas resistance, and is easy to synthesize and inexpensive for black ink It is an object to provide a dye compound and an ink composition thereof.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific tetrakisazo compound can solve the above problems, and have reached 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 and R ² are each independently a hydrogen atom, halogen atom, cyano group, carboxyl group, sulfo group, sulfamoyl group, N-alkylaminosulfonyl group, N-phenylaminosulfonyl group, hydroxyl group. (C1-C4) alkylsulfonyl group, phospho group, nitro group, acyl group, ureido group, (C1-C4) alkyl group (hydroxyl group or (C1-C4) alkoxy group) which may be substituted with a group Or (C1-C4) alkoxy group (which may be substituted with a hydroxyl group, (C1-C4) alkoxy group, sulfo group or carboxyl group), acylamino group, alkylsulfonylamino group or phenylsulfonylamino group. (The phenyl group may be substituted with a halogen atom, an alkyl group or a nitro group). ³ and R ⁴ are each independently substituted with a hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a sulfo group, a nitro group, a (C1-C4) alkyl group (hydroxyl group or (C1-C4) alkoxy group). Or (C1-C4) alkoxy group (the alkyl group may be substituted with a hydroxyl group, (C1-C4) alkoxy group, sulfo group or carboxyl group), R ⁵ and R ⁶ are each independently Hydrogen atom, (C1 to C8) alkyl group (which may be substituted with hydroxyl group, carboxyl group, sulfo group or N, N-dialkylamino group), (C1 to C8) alkoxyalkyl group (hydroxyl group or ( C1-C4) which may be substituted with an alkoxy group) or phenyl group (hydroxyl group, carboxyl group, sulfo group, alkyl group) The may) be substituted by an alkoxy group, R ^7, R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a sulfo group, a sulfamoyl group, N- alkylaminosulfonyl group , N-phenylaminosulfonyl group, nitro group, acyl group, (C1-C4) alkylsulfonyl group, (C1-C4) alkyl group (hydroxyl group or (C1-C4) alkoxy group) which may be substituted with hydroxyl group N may represent 0 or 1 (which may be substituted) or (C1-C4) alkoxy group (which may be substituted with a hydroxyl group, (C1-C4) alkoxy group, carboxyl group or sulfo group). ),
(2) The azo compound or the azo compound according to (1), wherein R ¹ is a carboxyl group or a sulfo group, R ² is a hydrogen atom, R ³ is a sulfo group, R ⁸ is a carboxyl group or a sulfo group, and n is 1. salt,
(3) When R ¹ is a sulfo group and the substitution position of R ¹ is ortho to the azo group, the substitution position of the nitro group is para to the azo group, and the substitution position of R ¹ is the azo group On the other hand, in the para position, the substitution position of the nitro group is ortho to the azo group (1) or the azo compound or salt thereof according to (2),
(4) Any one of (1) to (3), wherein R ⁴ is a hydrogen atom, a halogen atom, a carboxyl group or a sulfo group, R ⁷ is a hydrogen atom, and R ⁹ is a hydrogen atom, a carboxyl group or a sulfo group. The azo compound or a salt thereof according to the item,
(5) Any of (1) to (4), wherein R ⁵ and R ⁶ are each independently a hydrogen atom, a hydroxyl group-substituted (C1-C4) alkyl group or a hydroxyl group-substituted (C1-C6) alkoxyalkyl group The azo compound or a salt thereof according to one item,
(6) The azo compound or a salt thereof according to (1), wherein the azo compound represented by the formula (1) or a salt thereof is an azo compound represented by the following formula (2) or a salt thereof,

(In formula (2), R ⁵¹ is a hydroxyl group-substituted (C1-C4) alkyl group or a hydroxyl group-substituted (C1-C6) alkoxyalkyl group)
(7) An ink composition comprising at least one azo compound or salt thereof according to any one of (1) to (6),
(8) An inkjet print recording method comprising using the ink composition according to (7),
(9) The inkjet print recording method according to (8), wherein the recording material in the inkjet print recording method is an information transmission sheet,
(10) The inkjet print recording method according to (9), wherein the information transmission sheet contains a porous white inorganic substance,
(11) An ink jet printer loaded with a container containing the ink composition according to (7),
(12) A colored body colored with the azo compound or a salt thereof according to any one of (1) to (6),
About.

Since the azo compound of the present invention or a salt thereof (hereinafter, both are simply referred to as an azo compound) is excellent in water solubility, the filterability of the membrane filter in the ink composition production process is good, and the recording liquid is stored. Excellent stability and discharge stability. Further, the ink composition of the present invention containing this azo compound has good storage stability without crystal precipitation, physical property change, color change and the like after long-term storage. The ink composition containing the azo compound of the present invention is preferably used for ink jet recording and writing instruments, and has a high print density of recorded images when recorded on plain paper and ink jet dedicated paper, and a high concentration solution. Even when printed, the image does not cause bronzing and is excellent in various fastness properties, particularly ozone gas resistance. By using it together with an ink composition using magenta, cyan and yellow dyes, full-color ink jet recording with excellent fastness and storage stability is possible. Thus, 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.
In R ¹ and R ² in Formula (1), examples of the N-alkylaminosulfonyl group include N-methylaminosulfonyl group, N-ethylaminosulfonyl group, N- (n-butyl) aminosulfonyl group, N , N-dimethylaminosulfonyl group, N, N-di (n-propyl) aminosulfonyl group and the like.

Examples of the (C1-C4) alkylsulfonyl group which may be substituted with a hydroxyl group in R ¹ , R ² , R ⁷ , R ⁸ and R ⁹ in the formula (1) include, for example, methylsulfonyl, ethylsulfonyl, propyl Examples include sulfonyl, butylsulfonyl, hydroxyethylsulfonyl, 2-hydroxypropylsulfonyl and the like.

In R ¹ and R ² in Formula (1), examples of the acyl group include acetyl, propionyl, butyryl, isobutyryl, benzoyl, naphthoyl, and the like.

Examples of R ¹ to R ⁴ , R ⁷ , R ⁸ and R ⁹ in formula (1) include (C1 to C4) alkyl groups which may be substituted with hydroxy groups or (C1 to C4) alkoxy groups. Methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, methoxyethyl, 2-ethoxyethyl, n-propoxy Examples include ethyl, isopropoxyethyl, n-butoxyethyl, methoxypropyl, ethoxypropyl, n-propoxypropyl, isopropoxybutyl, n-propoxybutyl and the like.

Examples of the alkyl group which may be substituted with a hydroxy group, a carboxyl group, a sulfo group or an N, N-dialkylamino group in R ⁵ and R ⁶ in the formula (1) include, for example, methyl, ethyl N-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 3-methyl-2-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methyl-3-pentyl, 4-methylpentyl, 2,2-dimethyl-3-pentyl, n-hexyl, 2-ethylhexyl, n-octyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2,3-dihydroxypropyl, 1,3-dihydroxy- 2-ethyl-2-propyl, 4-hydroxybutyl, 5-hydroxypentyl, 6-hydroxyhexyl, cal Examples include boxymethyl, 2-carboxyethyl, 3-carboxypropyl, 5-carboxypentyl, 2-sulfoethyl, 3-sulfopropyl, 4-sulfobutyl, N, N-dimethylaminopropyl, N, N-diethylaminopropyl, and the like.

Examples of (C1-C8) alkoxyalkyl group optionally substituted by hydroxyl group or (C1-C4) alkoxy group in R ⁵ and R ⁶ in formula (1) include, for example, methoxymethyl, 2-methoxyethyl 2-ethoxyethyl, 3-ethoxypropyl, 4-ethoxybutyl, 4-butoxybutyl, 2- (2-methoxyethoxy) ethyl, 2- (2-ethoxyethoxy) ethyl, 2- (2-hydroxyethoxy) ethyl , 3- (2-hydroxyethoxy) propyl and the like.

Examples of the phenyl group which may be substituted with a hydroxyl group, a carboxyl group, a sulfo group, an alkyl group or an alkoxy group in R ⁵ and R ⁶ in the formula (1) include, for example, phenyl, 3-methylphenyl, 4- Methylphenyl, 2,5-dimethylphenyl, 4-methoxyphenyl, 2,5-diethoxyphenyl, 2-methoxy-5-methylphenyl, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2-hydroxy Examples include -5-methylphenyl, 4-carboxyphenyl, 3,5-dicarboxyphenyl, 3-carboxy-4-hydroxyphenyl, 3-sulfophenyl, 2-methoxy-5-sulfophenyl and the like.

In R ¹ to R ⁴ , R ⁷ , R ⁸ and R ⁹ in formula (1), a (C1-C4) alkoxy group which may be substituted with a hydroxy group, a (C1-C4) alkoxy group, a sulfo group or a carboxyl group Examples of are, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy, methoxyethoxy, ethoxyethoxy, n-propoxyethoxy, isopropoxyethoxy, n-butoxyethoxy, methoxypropoxy, ethoxypropoxy, n-propoxypropoxy, isopropoxybutoxy, n-propoxybutoxy, 2-hydroxyethoxyethoxy, carboxymethoxy, 2-carboxyethoxy, 3 Carboxy propoxy, 3-sulfopropoxy, 4-sulfobutoxy and the like.

In R ¹ and R ² in Formula (1), examples of the acylamino group include acetylamino, propionylamino, butyrylamino, isobutyrylamino, benzoylamino, naphthoylamino, and the like.

In R ¹ and R ² in Formula (1), examples of the alkylsulfonylamino group include methylsulfonylamino, ethylsulfonylamino, propylsulfonylamino and the like.

Examples of the phenylsulfonylamino group which may be substituted with a halogen atom, an alkyl group or a nitro group in R ¹ and R ² in the formula (1) include, for example, benzenesulfonylamino, toluenesulfonylamino, chlorobenzenesulfonylamino, nitrobenzenesulfonyl Amino and the like.

Preferred R ¹ and R ² in the formula (1) are hydrogen atom, chlorine atom, bromine atom, cyano group, carboxyl group, sulfo group, sulfamoyl group, N-methylaminosulfonyl group, N-phenylaminosulfonyl group, methylsulfonyl. Group, hydroxyethylsulfonyl group, phosphate group, nitro group, acetyl group, benzoyl group, ureido group, methyl group, methoxy group, ethyl group, ethoxy group, propyl group, propoxy group, 2-hydroxyethoxy group, 2-methoxy group An ethoxy group, a 2-ethoxyethoxy group, a 3-sulfopropoxy group, a 4-sulfobutoxy group, a carboxymethoxy group, a 2-carboxyethoxy group, an acetylamino group, a benzoylamino group, and more preferably a hydrogen atom, chlorine Atom, cyano group, sulfamoyl group, acetyl group, methylsulfo Nyl group, hydroxyethylsulfonyl group, nitro group, carboxyl group and sulfo group, more preferably hydrogen atom, carboxyl group and sulfo group. Further preferred R ¹ is a carboxyl group or a sulfo group, and a sulfo group is particularly preferred. R ² is particularly preferably a hydrogen atom. When the substitution position of R ¹ is ortho to the azo group, the substitution position of the nitro group is para to the azo group, and when the substitution position of R ¹ is para to the azo group, The substitution position of the group is preferably ortho to the azo group.

Preferred R ³ and R ⁴ in the formula (1) are hydrogen atom, chlorine atom, cyano group, carboxyl group, sulfo group, nitro group, methyl group, methoxy group, ethyl group, ethoxy group, propyl group, propoxy group, 2 -Hydroxyethoxy group, 2-methoxyethoxy group, 2-ethoxyethoxy group, 3-sulfopropoxy group, 4-sulfobutoxy group, carboxymethoxy group, 2-carboxyethoxy group, etc., more preferably hydrogen atom, chlorine An atom, a carboxyl group, a sulfo group, a methyl group, and a methoxy group are preferable, and a hydrogen atom and a sulfo group are more preferable. A combination in which R ³ is a sulfo group and R ⁴ is a hydrogen atom is particularly preferable.

Preferred R ⁵ and R ⁶ in the formula (1) are hydrogen atom, methyl group, ethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-sulfoethyl group. 2-carboxyethyl group, 3-carboxypropyl group, 5-carboxypentyl group, 2-methoxyethyl group, 2-ethoxyethyl group, 2,3-dihydroxypropyl group, 2- (2-ethoxyethoxy) ethyl group, 2- (2-hydroxyethoxy) ethyl group, 3- (2-hydroxyethoxy) propyl group, phenyl group, 3-methylphenyl group, 2,5-diethoxyphenyl group, 3-sulfophenyl group, 3,5- A carboxyphenyl group and the like, more preferably a hydrogen atom, a 2-hydroxyethyl group, a 2-hydroxypropyl group, and a 2-ethyl group. Toxiethyl group, 2,3-dihydroxypropyl group, 2- (2-ethoxyethoxy) ethyl group, 2- (2-hydroxyethoxy) ethyl group, more preferably hydrogen atom, 2-hydroxyethyl group, 2- (2-Ethoxyethoxy) ethyl group. Further, a combination in which R ⁵ is a 2-hydroxyethyl group, 2- (2-ethoxyethoxy) ethyl group, and R ⁶ is a hydrogen atom is particularly preferable.

Preferred R ⁷ to R ⁹ in formula (1) are a hydrogen atom, a chlorine atom, a bromine atom, a cyano group, a carboxyl group, a sulfo group, a sulfamoyl group, an N-methylaminosulfonyl group, an N-phenylaminosulfonyl group, a methylsulfonyl Group, hydroxyethylsulfonyl group, nitro group, acetyl group, benzoyl group, methyl group, methoxy group, ethyl group, ethoxy group, propyl group, propoxy group, 2-hydroxyethoxy group, 2-methoxyethoxy group, 2-ethoxyethoxy Group, 3-sulfopropoxy group, 4-sulfobutoxy group, carboxymethoxy group, 2-carboxyethoxy group, etc., more preferably hydrogen atom, chlorine atom, methyl group, methylsulfonyl group, hydroxyethylsulfonyl group, carboxyl Group, a sulfo group, more preferably hydrogen An atom, a carboxyl group, and a sulfo group.
A combination in which R ⁷ is a hydrogen atom, R ⁸ is a sulfo group, and R ⁹ is a hydrogen atom is particularly preferable.

As an example of a more preferable compound, the azo compound represented by following formula (2) is mentioned.

(In formula (2), R ⁵¹ represents a hydroxyl group-substituted (C1-C4) alkyl group or a hydroxyl group-substituted (C1-C6) alkoxyalkyl group.)

The salt of the azo compound represented by the formulas (1) and (2) is an inorganic or organic cation salt. Of these, specific examples of inorganic salts include alkali metal salts, alkaline earth metal salts, and ammonium salts. Preferred inorganic salts are lithium, sodium, potassium, and ammonium salts, and organic cation salts. Examples of the salt include, but are not limited to, salts of compounds represented by the following formula (3).

Specific examples of the alkyl group represented by Z ¹ , Z ² , Z ³ and Z ^{4 in} the formula (3) include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and the like. Specific examples of the hydroxyalkyl group include hydroxymethyl group, hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 2-hydroxybutyl group and the like. -(C1-C4) alkyl groups are exemplified, and examples of hydroxyalkoxyalkyl groups include hydroxyethoxymethyl group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, 2-hydroxyethoxypropyl group, 4-hydroxy Ethoxybutyl group, 3-hydroxyethoxybutyl group 2-hydroxyethoxy-butyl group such as hydroxyethyl (C1 -C4) alkoxy - (C1 -C4) alkyl group. Among these hydroxyethoxy - (C1 -C4) alkyl groups are preferred. Particularly preferred are hydrogen atom; methyl group; hydroxymethyl group, hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 2-hydroxybutyl group, etc. Hydroxy- (C1-C4) alkyl group; hydroxyethoxymethyl group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, 2-hydroxyethoxypropyl group, 4-hydroxyethoxybutyl group, 3-hydroxyethoxybutyl group, Examples include hydroxyethoxy- (C1-C4) alkyl groups such as 2-hydroxyethoxybutyl group.

Specific examples of Z ¹ , Z ² , Z ³ and Z ^{4 in} the formula (3) are shown in Table 1.

The azo compound of the present invention represented by the formula (1) can be synthesized, for example, by the following method. Moreover, the structural formula of the compound in each process shall be represented with the form of a free acid.
Following formula (4)

(In formula (4), n has the same meaning as in formula (1).)
Formula (5) obtained by reaction of p-toluenesulfonyl chloride with alkali in the presence of an alkali

(In formula (5), n has the same meaning as described above.)
The compound represented by the formula (6) produced by diazotization by a conventional method and coupling reaction with 4-amino-5-naphthol-1,7-disulfonic acid under acidic conditions

(In formula (6), n has the same meaning as described above.)
A compound represented by formula (7):

(In formula (7), R ¹ and R ² have the same meaning as in formula (1).)
A compound obtained by diazotizing a compound represented by formula (8) by a coupling reaction is obtained.

(In formula (8), R ¹ , R ² and n have the same meaning as described above.)
The compound represented by the formula (9) is hydrolyzed under alkaline conditions.

(In formula (9), R ¹ , R ² and n have the same meaning as described above.)
To obtain a compound represented by: Where equation (10)

(In formula (10), R ^{3 to} R ⁹ have the same meaning as in formula (1).)
A azo compound of the present invention represented by the formula (1) or a salt thereof can be obtained by subjecting a monoazo compound represented by formula (II) to diazotization by a conventional method to a coupling reaction.

The monoazo compound of formula (10) can be synthesized by a conventional method. For example, the following formula (11)

(In formula (11), R ³ and R ⁴ have the same meaning as in formula (1).)
And a compound (12) obtained by diazotizing a compound represented by the formula

(In the formula (12), R ^{5 to} R ⁹ have the same meaning as in the formula (1).)
Formula (13) obtained by coupling reaction with the compound represented by

(In formula (13), R ^{3 to} R ⁹ have the same meaning as in formula (1).)
It can be obtained by reducing the nitro group of the compound represented by

Although it does not specifically limit as a suitable specific example of the compound of this invention shown in Formula (1), The compound shown by a following formula is mentioned. In each table, the sulfo group and the carboxyl group are expressed in the form of a free acid.

Table 2

Table 3

Table 4

Table 5

The esterification reaction of the compound of formula (4) with p-toluenesulfonyl chloride is carried out in a manner known per se, in an aqueous or aqueous organic medium, for example at a temperature of 20 to 100 ° C., preferably 30 to 80 ° C. It is advantageous to carry out at a pH value that is neutral to alkaline. It is preferably carried out at a neutral to weakly alkaline pH value, for example, pH 7-10. The pH value is adjusted by adding a base. Examples of the base include alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate, and acetates such as sodium acetate. The compound of formula (4) and p-toluenesulfonyl chloride are used in approximately stoichiometric amounts.

The diazotization of the compound of formula (5) is carried out in a manner known per se, for example nitrites, such as sodium nitrite, in an inorganic acid medium, for example at a temperature of -5 to 30 ° C., preferably 5 to 15 ° C. It is carried out using an alkali metal nitrite salt. Coupling of a diazotized compound of formula (5) with 4-amino-5-naphthol-1,7-disulfonic acid is also carried out under conditions known per se. It is advantageous to carry out in an aqueous or aqueous organic medium, for example at a temperature of -5 to 30 [deg.] C, preferably 5 to 25 [deg.] C and an acidic to neutral pH value. The coupling bath is acidified but is preferably carried out at an acidic to slightly acidic pH value, for example pH 1-4. The pH value is adjusted by adding a base. Examples of the base that can be used include alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate, acetates such as sodium acetate, ammonia and organic amines. . The compound of formula (5) and 4-amino-5-naphthol-1,7-disulfonic acid are used in approximately stoichiometric amounts.

The diazotization of the compound of formula (7) is also carried out in a manner known per se, for example a subnitrite such as nitrite, for example sodium nitrite, in an inorganic acid medium, for example at a temperature of -5 to 30 ° C, preferably 0 to 15 ° C. It is carried out using an alkali metal nitrate. Coupling of the diazotized compound of the compound of formula (7) and the compound of formula (6) is also carried out under conditions known per se. It is advantageous to carry out the reaction in an aqueous or aqueous organic medium, for example at a temperature of -5 to 30 ° C, preferably 10 to 25 ° C and a weakly acidic to alkaline pH value. It is preferably carried out at a weakly acidic to weakly alkaline pH value, for example, pH 5 to 10, and the pH value is adjusted by adding a base. Examples of the base 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. it can. The compounds of formulas (6) and (7) are used in approximately stoichiometric amounts.

Production of the compound of formula (9) by hydrolysis of the compound of formula (8) is also carried out by a method known per se. The heating is preferably carried out in an aqueous alkaline medium. For example, sodium hydroxide or potassium hydroxide is added to a solution containing the compound of formula (8) to adjust the pH to 9.5 or higher, and then, for example, 20 to 150 ° C. Is carried out by heating to a temperature of 30 to 100 ° C. At this time, the pH value of the reaction solution is preferably maintained at 9.5 to 11.5. The pH value is adjusted by adding a base. As the base, those described above can be used.

The diazotization of the compound of formula (10) is also carried out in a manner known per se, for example a subnitrite such as nitrite, for example sodium nitrite, in an inorganic acid medium, for example at a temperature of -5 to 30 ° C, preferably 0 to 15 ° C. It is carried out using an alkali metal nitrate. Coupling of the diazotized compound of the compound of formula (10) and the compound of formula (9) is also carried out under conditions known per se. It is advantageous to carry out the reaction in an aqueous or aqueous organic medium, for example at a temperature of -5 to 30 ° C, preferably 10 to 25 ° C and a weakly acidic to alkaline pH value. It is preferably carried out at a weakly acidic to weakly alkaline pH value, for example, pH 5 to 10, and the pH value is adjusted by adding a base. Examples of the base 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. it can. The compounds of formulas (9) and (10) are used in approximately stoichiometric amounts.

The diazotization of the compound of formula (11) is also carried out in a manner known per se, for example a subnitrite such as a nitrite, for example sodium nitrite, in an inorganic acid medium, for example at a temperature of -5 to 30 ° C, preferably 0 to 15 ° C. It is carried out using an alkali metal nitrate. Coupling of the diazotized compound of the compound of formula (11) and the compound of formula (12) is also carried out under conditions known per se. It is advantageous to carry out the reaction in an aqueous or aqueous organic medium, for example at a temperature of -5 to 30 ° C, preferably 10 to 25 ° C and a weakly acidic to alkaline pH value. It is preferably carried out at a weakly acidic to weakly alkaline pH value, for example, pH 4 to 10, and the pH value is adjusted by adding a base. Examples of the base 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. it can. The compounds of formulas (11) and (12) are used in approximately stoichiometric amounts.

Production of the compound of formula (10) by reduction reaction of the nitro group of the compound of formula (13) is also carried out by a method known per se. For example, in an aqueous or aqueous organic medium containing the compound of formula (13), an alkali metal sulfide or hydrosulfide such as sodium sulfide or sodium hydrosulfide is added, for example, a temperature of 10 to 120 ° C., preferably 15 to 80 ° C. As well as at a mildly alkaline to alkaline pH value. The pH value is adjusted by adding a base. Examples of the base include alkali metal hydroxides such as lithium hydroxide and sodium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate, and acetates such as sodium acetate.

The azo compound represented by the formula (1) of the present invention can be isolated in the form of a free acid by adding a mineral acid after the coupling reaction, and the inorganic salt is removed therefrom by washing with water or acidified water. I can do it. Next, the acid type dye (compound) having a low salt content thus obtained can be neutralized with a desired inorganic or organic base in an aqueous medium to form a corresponding salt solution. . Examples of inorganic bases include, for example, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide, or alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate. Examples of the organic base include, but are not limited to, organic amines such as alkanolamines represented by the above formula (3) such as diethanolamine and triethanolamine.

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

The reaction liquid containing the azo compound of the present invention represented by the formula (1) can be used directly for the production of an ink composition. However, it is first isolated by drying, eg spray drying, or salted out with inorganic salts such as sodium chloride, potassium chloride, calcium chloride, sodium sulfate or acidified with mineral acids such as hydrochloric acid, sulfuric acid, nitric acid. Alternatively, the azo compound of the present invention can be taken out by acid salting out by combining salting out and aciding out, and then processed into an ink composition.

The ink composition of the present invention usually contains water containing 0.1 to 20% by mass, preferably 1 to 10% by mass, more preferably 2 to 8% by mass of the azo compound represented by the formula (1) of the present invention. It is a composition as a main medium. The ink composition of the present invention may further contain, for example, 0 to 30% by mass of a water-soluble organic solvent and 0 to 5% by mass of an ink preparation agent, for example. The pH of the ink composition is preferably 5 to 11 and more preferably 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 is obtained by dissolving the azo compound represented by the above formula (1) in water or a water-soluble organic solvent (an organic solvent miscible with water), and adding an ink preparation agent as necessary. is there. When this ink composition is used as an ink for an ink jet printer, the azo compound of the present invention is preferably one having a low content of inorganic substances such as metal cation chlorides and sulfates. Is approximately 1% by mass or less (relative to the chromogen). In order to produce the azo compound of the present invention with a small amount of inorganic substances, for example, a usual method using a reverse osmosis membrane or a dried product or wet cake of the azo compound of the present invention is stirred in a mixed solvent of alcohol such as methanol and water and filtered. What is necessary is just to desalinate by the method of fractionation and drying.

Specific examples of water-soluble organic solvents that can be used in the preparation of the ink composition include C1-C4 alkanols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, and tert-butanol, N, N -Carboxylic acid amides such as dimethylformamide or N, N-dimethylacetamide, lactams such as 2-pyrrolidone and N-methylpyrrolidin-2-one, 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexa Cyclic ureas such as hydropyrimido-2-one, ketones such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one or cyclic ethers such as keto alcohol, tetrahydrofuran, dioxane, 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 glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, thio Monomers, oligomers, polyalkylene glycols or thioglycols such as diglycol and dithiodiglycol units, polyols such as glycerin and hexane-1,2,6-triol (triol), ethylene glycol monomethyl ether Or ethylene glycol monoethyl ether, diethylene glycol monomethyl ether or diethylene glycol monoethyl ether or triethylene glycol Roh methyl ether or triethylene glycol polyhydric alcohol (C1 -C4) alkyl ethers of mono-ethyl ether, gamma-butyrolactone or dimethyl sulfoxide and the like. These organic solvents may be used alone or in combination of two or more.

Examples of the ink preparation 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. And surfactants. These drugs are described below.

Specific 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, for example, organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzo Thiazole, isothiazoline, dithiol, pyridine oxyd, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, Examples include benzyl bromacetate and inorganic salt compounds. Specific examples of the organic halogen compound include sodium pentachlorophenol, and specific examples of the pyridine oxidoxide compound include, for example, 2-pyridinethiol-1-oxide sodium, and specific examples of the inorganic salt compound. Examples thereof include sodium acetate anhydride. Examples of the isothiazoline-based compound include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, and 5-chloro-2-methyl- 4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4- And isothiazoline-3-one calcium chloride. Specific examples of other antiseptic / antifungal agents include sodium sorbate and sodium benzoate.

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

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

Specific examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.
Examples of water-soluble ultraviolet 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, heterocycles, and the like. It is done.

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, alkylallylsulfone hydrochloride, Examples include diethylsulfosuccinate, diethylhexylsylsulfosuccinate, and dioctylsulfosuccinate. 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 and other imidazolines. There are 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, polyoxyethylene alkyl ether, Ethers such as oxyallylalkyl alkyl ether, polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxy Esters such as ethylene monooleate and polyoxyethylene stearate, 2,4,7,9-tetramethyl-5-decyne-4 Acetylene glycols such as 7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3ol (for example, Surfinol 104, 105 manufactured by Nissin Chemical Co., Ltd.) , 82, 465, orlphine STG, etc.). These 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. The obtained ink composition may be filtered with a membrane filter or the like, if desired, in order to remove impurities. Moreover, in order to adjust the black color as an ink composition, in addition to the azo compound represented by the formula (1) of the present invention, other dyes having various hues may be mixed. In that case, pigments having other hues such as black, yellow, magenta, cyan, and other colors can be mixed and used.

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. It is suitably used in the ink jet recording method of the invention.

Next, the ink jet recording method of the present invention will be described. The inkjet recording method of the present invention is characterized in that recording is performed using the ink composition of the present invention. In the ink jet recording method of the present invention, recording is performed on an image receiving material using an ink jet ink containing the ink composition, but there are no particular restrictions on the ink nozzles used at that time, depending on the purpose. Known methods, for example, a charge control method that ejects ink using electrostatic attraction, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezo element, and an electrical signal An acoustic ink jet system that converts ink into an acoustic beam and irradiates the ink by using radiation pressure to eject the ink, thermal ink jet that forms bubbles by heating the ink and uses the generated pressure (Bubble Jet (registered trademark)) A method etc. can be adopted. The inkjet recording method includes a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving image quality using a plurality of inks having substantially the same hue and different concentrations, and colorless and transparent. A method using ink is included.

The colored product of the present invention is colored with the compound of the present invention or an ink composition containing the compound, and more preferably is colored with an ink jet printer using the ink composition of the present invention. Examples of materials that can be colored include information transmission sheets such as paper and film, fibers and cloth (cellulose, nylon, wool, etc.), leather, and base materials for color filters. Among them, 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. For the ink-receiving layer, for example, a porous white inorganic substance capable of absorbing the pigment in the ink such as porous silica, alumina sol, and special ceramics by impregnating or coating the above-mentioned base material with a cationic polymer is used. It is provided by coating the surface of the substrate together with a hydrophilic polymer such as polyvinylpyrrolidone. A paper provided with such an ink receiving layer is usually called an inkjet exclusive paper (film), glossy paper (film), etc., for example, Pictorico (manufactured by Asahi Glass Co., Ltd.), professional photo paper, super photo paper, matte photo paper. (All made by Canon Inc.), PM photo paper (glossy), PM matte paper (all made by Seiko Epson Corp.), premium plus photo paper, premium gloss film, photo paper (all by Hewlett-Packard Japan) Commercially available products such as Photo-like QP (manufactured by Konica Corporation) are available. Of course, plain paper can also be used.

  Among these, it is known that the image recorded on the information transmission sheet coated with a porous white inorganic substance on the surface is greatly discolored by ozone gas, but the ink composition of the present invention is resistant to ozone gas. Since it is excellent, it is particularly effective when recording 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 recording is performed by a normal method. Record it on the material. In the ink jet recording method of the present invention, a black ink composition of the present invention, a publicly known magenta ink composition, a cyan ink composition, a yellow ink composition, and a green ink composition, blue (or violet) as necessary. It can be used in combination with an ink composition and a red ink composition. The ink composition of each color is poured into each container, and the container is used by being loaded into a predetermined position of the ink jet printer in the same manner as the container containing the aqueous black ink composition for ink jet recording of the present invention. Examples of the ink jet printer include a piezo printer using mechanical vibration and a bubble jet (registered trademark) printer using bubbles generated by heating.

The azo compound of the present invention is excellent in water solubility, and the ink composition of the present invention containing this azo compound has good storage stability without crystal precipitation, physical property change, color change, etc. after long-term storage. Further, the black ink composition for recording containing the azo compound of the present invention is used for ink jet recording and writing instruments, and when recorded on plain paper and ink jet dedicated paper, the recorded image exhibits a black with high print density. Furthermore, its ozone gas resistance, light resistance and bronzing properties are excellent.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited at all by the following examples. In the text, “parts” and “%” are based on mass unless otherwise specified. In the following formulas, the sulfone group is expressed in the form of a free acid.

Example 1
(1) After reacting 6.4 parts of 2-amino-5-naphthol-1,7-disulfonic acid and 4.1 parts of p-toluenesulfonyl chloride at pH 8.0 to 8.5 at 70 ° C. for 1 hour. Then, 8.8 parts of the compound of the formula (14) obtained by salting out by acidification and separation by filtration was dissolved in 90 parts of water while adjusting the pH to 6.0 to 8.0 with sodium carbonate, and 35% After addition of 6.8 parts of hydrochloric acid, the temperature was changed to 0 to 5 ° C., and 3.6 parts of 40% aqueous sodium nitrite solution was added to diazotize.

To this diazo suspension, a solution obtained by suspending 6.3 parts of 4-amino-5-hydroxynaphthalene-1,7-disulfonic acid in 60 parts of water was added, and then the pH value of the solution was carbonated at 10 to 20 ° C. It stirred for 4 hours, hold | maintaining to 2.4-2.8 with sodium. Subsequently, it melt | dissolved as 7.0-8.5 with sodium carbonate, and the solution containing the monoazo compound of Formula (15) was obtained.

(2) Dissolve 5.2 parts of sodium 4-nitroaniline-2-sulfonate in 50 parts of water, and 6.4 parts of 35% hydrochloric acid and 4.0 parts of 40% aqueous sodium nitrite solution at 0-5 ° C. Was added to diazotize. While maintaining this diazo suspension in a solution containing the monoazo compound of the formula (15) obtained by the above reaction at 10 to 20 ° C. and maintaining the pH value of the solution at 8.0 to 9.0 with sodium carbonate, It was dripped. After completion of dropping, the mixture was stirred at 15 to 30 ° C. for 2 hours at pH 8.0 to 9.0 to obtain a solution containing a disazo compound of the formula (16).

The solution obtained above was heated to 70 ° C. and stirred for 1.5 hours while maintaining the pH value at 10.5 to 11.0 with sodium hydroxide. After cooling to room temperature, the pH was adjusted to 7.0 to 8.0 with 35% hydrochloric acid, sodium chloride was added for salting out, and filtration was performed to obtain a wet cake containing the compound of formula (17).

(3) A solution obtained by adding 5.6 parts of the compound of formula (18) to 12.2 parts of 2-aminoethanol was stirred at 100 ° C. for 3 hours to obtain a solution containing the compound of formula (19).

(4) 4.3 parts of sodium 4-nitroaniline-2-sulfonate is dissolved in 40 parts of water, and 5.2 parts of 35% hydrochloric acid and 3.3 parts of 40% aqueous sodium nitrite solution are added thereto at 0 to 5 ° C. Was added to diazotize. The diazo suspension was diluted with a solution containing the compound of the formula (19) obtained in the above reaction with 40 parts of water and then added with 35% hydrochloric acid to adjust the pH value to 8.0. The solution was added dropwise while maintaining the pH value of the solution at 7.0 to 8.0 with sodium carbonate. After completion of dropping, the mixture was stirred at 15 to 30 ° C. for 2 hours at pH 7.0 to 8.0 to obtain a solution containing the monoazo compound of the formula (20).

A solution prepared by dissolving 7.3 parts of sodium sulfide nonahydrate in 20 parts of water was added dropwise to the solution obtained above at 15 to 30 ° C. After dropping, the mixture is stirred at 15 to 30 ° C. for 2 hours, acidified to pH by adding 35% hydrochloric acid, salted out by adding sodium chloride, and filtered to obtain a wet cake containing the compound of formula (21). Obtained.

(5) The wet cake containing the compound of the formula (21) obtained above was dissolved in 50 parts of water by adding lithium hydroxide, and 2.7 parts of 40% aqueous sodium nitrite solution was added. This solution was dropped into a solution obtained by adding 5.8 parts of 35% hydrochloric acid to 30 parts of water at 15 to 30 ° C. to diazotize. This diazo suspension was dissolved in a solution obtained by dissolving a wet cake containing the compound of formula (17) in 140 parts of water at 15 to 30 ° C., and the pH value of the solution was 8.0 to 9.0 with lithium hydroxide. The solution was added dropwise while being held. After completion of the dropwise addition, the mixture was stirred at 15 to 30 ° C. for 2 hours at pH 8.0 to 9.0, salted out by addition of lithium chloride, and collected by filtration. The obtained wet cake was dissolved in 120 parts of water, and crystallization and filtration were performed by adding 350 parts of 2-propanol. Further, the obtained wet cake was dissolved in 100 parts of water, and then crystallized by adding 300 parts of 2-propanol, filtered and collected, and dried to obtain an azo compound of formula (22) of the present invention (No. 4 in Table 2). 13.9 parts of this compound was obtained as a mixed salt of lithium and sodium. The maximum absorption wavelength (λmax) of this compound in an aqueous solution at pH 9 was 608 nm, and the solubility was 100 g / l or more.

Example 2
In the same manner as in Example 1 except that 12.2 parts of 2-aminoethanol in (3) of Example 1 were changed to 18.9 parts of 2- (2-aminoethoxy) ethanol, 14.1 parts of an azo compound (compound No. 9 in Table 2) were obtained as a mixed salt of lithium and sodium. The maximum absorption wavelength (λmax) of this compound in an aqueous solution at pH 9 was 607 nm, and the solubility was 100 g / l or more.

Example 3
14.4 parts of sodium 4-nitroaniline-2-sulfonate in (2) of Example 1 was changed to 14.4 parts of sodium 2-nitroaniline-4-sulfonate, and 2-amino in Example 3 (3). The azo compound of the formula (24) of the present invention (No. 10 compound in Table 2) was prepared in the same manner as in Example 1 except that 12.2 parts of ethanol was changed to 18.9 parts of 2- (2-aminoethoxy) ethanol. 14.7 parts were obtained as a mixed salt of lithium and sodium. The maximum absorption wavelength (λmax) of this compound in an aqueous solution at pH 9 was 609 nm, and the solubility was 100 g / l or more.

Example 4
In the same manner as in Example 1 except that 5.6 parts of the compound of the formula (18) in (3) of Example 1 are changed to 5.9 parts of the compound of the following formula (25), 13.8 parts of an azo compound (No. 23 compound in Table 2) was obtained as a mixed salt of lithium and sodium. The maximum absorption wavelength (λmax) of this compound in an aqueous solution at pH 9 was 608 nm, and the solubility was 100 g / l or more.

Example 5
4.3 parts of sodium 4-nitroaniline-2-sulfonate in (3) of Example 1 was changed to 4.9 parts of sodium 6-chloro-4-nitroaniline-2-sulfonate, and (3) of Example 1 The azo compound of the formula (27) of the present invention (No. in Table 2) was prepared in the same manner as in Example 1 except that 12.2 parts of 2-aminoethanol were 18.9 parts of 2- (2-aminoethoxy) ethanol. .20 compound) was obtained as a mixed salt of lithium and sodium. The maximum absorption wavelength (λmax) of this compound in an aqueous solution at pH 9 was 596 nm, and the solubility was 100 g / l or more.

Example 6-10
(A) Preparation of ink By mixing the following components, a black ink composition of the present invention was obtained, and impurities were removed by filtering with a 0.45 μm membrane filter.
The water used was ion exchange water. The pH during ink preparation was adjusted to 8-9 with ammonium hydroxide.

Table 6
Compounds obtained in the above examples 5.0 parts Glycerin 5.0 parts Urea 5.0 parts N-methyl-2-pyrrolidone 4.0 parts Isopropyl alcohol 3.0 parts Butyl carbitol 2.0 parts Surfactant 0.1 part (Surfinol 105 manufactured by Nissin Chemical)
Water + ammonium hydroxide 75.9 parts Total 100.0 parts

In Table 6, the compounds obtained in the above examples are the compounds of the formula (22) obtained in Example 1 in Example 6, and the compounds of the formula (23) obtained in Example 2 in Example 7. Example 8 is the compound of formula (24) obtained in Example 3, Example 9 is the compound of formula (26) obtained in Example 4, Example 10 is obtained in Example 5. The compounds of formula (27) are shown respectively. This aqueous ink composition did not cause precipitation separation during storage, and did not change its physical properties even after long-term storage.

(B) Inkjet printing Using each of the ink compositions obtained above, by using an inkjet printer (trade name BJ-S630 manufactured by Canon), plain paper (Canon LBP PAPER LS-500), exclusive glossy paper PR Inkjet recording was performed on four types of paper (Professional Photo Paper PR-101 manufactured by Canon Inc.), exclusive glossy paper PM (PM Photo Paper manufactured by EPSON (Glossy) KA420PSK), and glossy film (MJA4SP6 manufactured by Epson).
At the time of printing, an image pattern was made so that a gradation with several steps of reflection density was obtained, and a half-tone black printed matter was obtained (Because gray scale mode was used during printing, other than black recording liquid) Yellow, cyan, and magenta recording liquids are not used in combination.) Among the test methods described below, in the “print density” which is an item to be evaluated using a colorimeter, the portion having the highest D value was used when measuring the reflection density D value of the printed matter. Similarly, in measurement of “light resistance” test and “ozone gas resistance” test, which are items to be evaluated using a colorimeter, the reflection density D value of the printed material before the test is closest to 1.0. Measurement was performed using the gradation portion.

(C) Evaluation of recorded image
The recorded image by the water-based ink composition of the present invention was evaluated for four points: printing density (reflection density), density change after light resistance test, density change after ozone gas resistance test, and bronzing property. The ozone gas resistance test was performed only on the special glossy papers PR and PM, and the bronzing test was performed only on the glossy film. The results are shown in (Table 7). The specific test method is shown below.
1) Print density evaluation The print density (reflection density) of the recorded image was measured using a colorimeter (manufactured by GRETAG / SPM50 GRETAG), and the reflection density D value was calculated. The criteria are shown below.
○ Plain paper: 1.2 ≦ D Glossy paper: 2.0 ≦ D
Δ Plain paper: 1.0 ≦ D <1.2 Glossy paper: 1.8 ≦ D <2.0
× Plain paper: D <1.0 Glossy paper: D <1.8
2) Light resistance test Using a xenon weatherometer (Ci4000 ATLAS), a 2 mm thick glass plate was installed so that an air layer was formed between the printed sample and a humidity of 0.36 W / square meter with a humidity of 60 Irradiation was performed for 50 hours under the conditions of% RH and temperature of 24 ° C. After the test was completed, color measurement was performed using the above colorimeter. The dye residual ratio was calculated and evaluated by (reflection density after test / reflection density before test) × 100 (%). The determination was made according to the following criteria.
○ Residual rate: 95% or more △ Residual rate: less than 95% and 90% or more × Residual rate: less than 90% 3) Ozone gas resistance test Ozone concentration is 40 ppm using ozone weatherometer (manufactured by Suga Test Instruments Co., Ltd.) The print sample was left for 6 hours at a humidity of 60% RH and a temperature of 24 ° C. After the test, the measurement was performed using the above colorimeter. The dye residual ratio was calculated and evaluated by (reflection density after test / reflection density before test) × 100 (%). The determination was made based on the following.
◎ Residual rate: 80% or more ○ Residual rate: 60% or more and less than 80% △ Residual rate: 40% or more and less than 60% × Residual rate: Less than 40% 4) Gloss condition of the highest density part on the surface of the bronzing test gloss film Was observed by visual perception and evaluated according to the following criteria.
○ The surface of the printed part shows the same good gloss condition as the surface of the non-printed part. △ The surface of the printed part is slightly deteriorated compared to the surface of the non-printed part. × The surface of the printed part is Metallic glare and no gloss

Comparative Example 1
As a comparative object, an ink composition having the same ink composition as in Example 6-10 was prepared using one dye (the following formula (28)) in Table 1-1 of Patent Document 1 as a water-soluble inkjet dye. The results of printing density evaluation, light resistance evaluation, ozone gas resistance evaluation, and bronzing evaluation of the obtained recorded images are shown in Table 7.

Comparative Example 2
Similarly, as a comparison target, an ink having the same ink composition as that of Example 6-10 using a dye AN-250 (formula (29) below) described in Example 1 of Patent Document 3 as a water-soluble inkjet dye. A composition was prepared. The results of printing density evaluation, light resistance evaluation, ozone gas resistance evaluation, and bronzing evaluation of the obtained recorded images are shown in Table 7.

Table 7
Printing density Light resistance Ozone gas resistance Bronzing Example 6 (Formula (22))
Plain paper ○ ○ − −
Exclusive glossy paper PR ○ ○ △ −
Exclusive glossy paper PM ○ ○ ○ −
Glossy film − − − ○
Example 7 (Formula (23))
Plain paper ○ ○ − −
Exclusive glossy paper PR ○ ○ △ −
Exclusive glossy paper PM ○ ○ ○ −
Glossy film − − − ○
Example 8 (Formula (24))
Plain paper ○ ○ − −
Exclusive glossy paper PR ○ ○ △ −
Exclusive glossy paper PM ○ ○ ○ −
Glossy film − − − ○
Example 9 (Formula (26))
Plain paper ○ ○ − −
Exclusive glossy paper PR ○ ○ △ −
Exclusive glossy paper PM ○ ○ ○ −
Glossy film − − − ○
Example 10 (Formula (27))
Plain paper ○ ○ − −
Exclusive glossy paper PR ○ ○ △ −
Exclusive glossy paper PM ○ ○ ○ −
Glossy film − − − ○
Comparative Example 1 (Formula (28))
Plain paper ○ △ − −
Special glossy paper PR ○ △ × −
Exclusive glossy paper PM ○ ○ △ −
Glossy film − − − ×
Comparative Example 2 (Formula (29))
Plain paper ○ △ − −
Special glossy paper PR ○ △ × −
Exclusive glossy paper PM ○ ○ × −
Glossy film---△

From the results of Table 7, the ink composition containing the azo compound of the present invention has a high printing density, and is superior in light resistance, ozone gas resistance and bronzing property as compared with the conventional black dye (comparative example). I understand.
Further, since the azo compound of the present invention has a high solubility and is stable, a high concentration ink can be designed.

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 (7)

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

(In the formula (1), R ¹ is a sulfo group, R ² is a hydrogen atom, R ³ is a sulfo group,
R ⁴ is a hydrogen atom, a chlorine atom, a carboxyl group, or a sulfo group,
R ⁵ represents a (C1-C8) alkyl group substituted with a hydroxyl group or a (C1-C8) alkoxyalkyl group substituted with a hydroxyl group,
R ⁶ is a hydrogen atom, R ⁷ is a hydrogen atom, R ⁸ is a sulfo group,
R ⁹ represents a hydrogen atom, a (C1-C4) alkyl group,
n represents 1 and
When the substitution position of R ¹ is ortho to the azo group, the substitution position of the nitro group is para to the azo group, and when the substitution position of R ¹ is para to the azo group, the nitro group Is the ortho position relative to the azo group) An ink composition comprising at least one azo compound or salt thereof according to claim 1 . An ink-jet print recording method comprising using the ink composition according to claim 2. 4. The inkjet print recording method according to claim 3 , wherein the recording material in the inkjet print recording method is an information transmission sheet. 5. The ink jet print recording method according to claim 4 , wherein the information transmission sheet contains a porous white inorganic substance. An ink jet printer loaded with a container containing the ink composition according to claim 2. A colored product colored with the azo compound or salt thereof according to claim 1.