JP3517980B2 - Recording liquid - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid using an aqueous medium, and more particularly to a black recording liquid suitable as an inkjet recording liquid or a recording liquid for writing instruments.

[0002]

2. Description of the Related Art Conventionally, as a recording liquid for ink jet recording, a water-based ink in which an acidic dye or a direct dye is dissolved in an aqueous medium, or a solvent-based ink in which an oil-soluble dye is dissolved in an organic solvent is used. . Since the solvent-based ink uses a solvent, it has a problem in terms of environmental safety and thus has limited applications and cannot be used in offices, for example. On the other hand, since the water-based ink uses a water-soluble dye, there is a problem that the recorded matter is inferior in water resistance particularly when recorded on plain paper. In addition, the recorded matter of ink using these dyes is also insufficient in light resistance. The same applies to the recording liquid for writing instruments.

In order to improve the above-mentioned problems, an aqueous dispersion ink in which carbon black having excellent water resistance and light resistance is dispersed as an coloring material in an aqueous medium is partially used. However, the conventional aqueous dispersion ink of carbon black has a problem that the recording density of the recorded matter is insufficient and the color tone is brownish black. For example, JP-A-2-27687
No. 2, JP-A-2-276873, JP-A-2-2768
75, JP-A-3-66768, JP-A-3-1403.
77, JP-A-4-57859 to 57865, JP-A-4-59879, JP-A-4-3323773, JP-A-5-247391 and the like use a dye together in order to improve these problems. However, there is a problem in terms of water resistance.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a bluish black having good water resistance and preferable color tone even when recorded on plain paper for ink jet recording or writing instruments, and enables high density recording. Further, there is provided an aqueous pigment-dispersed ink using carbon black, which has good ejection properties, high recording reliability, and can be recorded with good robustness other than water resistance such as print quality and light resistance of recorded matter. That is the purpose.

[0005]

The gist of the present invention is that the group consisting of an aqueous medium, carbon black and a compound represented by the general formula [I], [II] or [III] in the free acid form in the above-mentioned claim 1. The recording liquid contains at least one selected from the group consisting of: Hereinafter, the present invention will be described in detail. The inventors of the present invention tested various dyes for improving the print density, color tone and water resistance of a water-based pigment-dispersed black ink for a recording liquid. As a result, in addition to carbon black, the above general formulas [I] and [II] were used. Further, it has been found that the combined use of the compound represented by the formula [III] exerts a particularly excellent effect on printing density, color tone and water resistance, and the present invention has been completed. The recording liquid prepared by using these compounds has good ejection stability during recording, is a bluish black with a favorable color tone, and can obtain a high-concentration recorded matter, and the printing quality of the recorded matter can be improved. In addition to good lightfastness and other fastnesses other than water resistance, recording is possible, and the stability of the recording liquid is also good, so that sedimentation of carbon black does not occur during long-term storage.

In the compounds represented by the above general formula [I], [II] or [III] whose free acid form is used in the recording liquid of the present invention, phenyls represented by A, C and E in the general formula The group or naphthyl group, and the phenylene group or naphthylene group represented by B, D and F, as a substituent, an acylamino group such as a sulfonic acid group, a carboxyl group, an amino group, an alkylcarbonylamino group and a benzoylamino group,
A substituted or unsubstituted alkyl group having 1 to 9 carbon atoms (for example, a linear or branched alkyl group having 1 to 9 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, and n-butyl group) Group, and groups in which these alkyl groups such as a trifluoromethyl group and a dimethylaminomethyl group are substituted with a fluorine atom, a substituted amino group, etc.), and a substituted or unsubstituted alkoxy group having 1 to 9 carbon atoms. (For example, a linear or branched alkoxy group having 1 to 9 carbon atoms such as a methoxy group, an ethoxy group, an isopropoxy group, and an n-butoxy group, and these alkoxy groups such as a hydroxyethoxy group and a methoxyethoxy group. Is a group substituted with a hydroxyl group, an alkoxy group, etc.), a hydroxyl group, a halogen atom such as a chlorine atom, a bromine atom, or a fluorine atom. It may have a plurality is.

The above general formulas [I], [II] and [III]
Medium, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R
Each of ₈ independently has a hydrogen atom and a carbon number of 1 to 1.
8 substituted or unsubstituted alkyl groups (for example, methyl group, ethyl group, n-butyl group, n-octyl group, ethylhexyl group and other linear or branched alkyl groups having 1 to 18 carbon atoms or hydroxy groups). Ethyl group, carboxypropyl group, carboxycyclohexylmethyl group, 1-carboxy-2-mercaptoethyl group, 1-carboxy-
These alkyl groups such as 2-carbamoylethyl group, 1-isopropyl-1-carboxymethyl group and 1,2-dicarboxypropyl group are substituted with hydroxyl group, carboxy group, carboxycyclohexyl group, mercapto group, carbamoyl group and the like. Groups. ), A substituted or unsubstituted alkenyl group having 1 to 18 carbon atoms (for example, a linear or branched alkenyl group such as a 2-methyl-1-propenyl group, a vinyl group, an allyl group and the like. It may be substituted with a carboxyl group, a halogen atom, a hydroxy group, etc.), an aryl group (for example, a phenyl group or a carboxyl such as a 3,4-dicarboxyphenyl group, 4-butylphenyl group, 4-carboxyphenyl group). Group, a phenyl group substituted with an alkyl group, etc.), an aralkyl group (for example, a phenylalkyl group having 7 to 15 carbon atoms such as a benzyl group, a phenylethyl group or the like, or a 1-carboxy-2-phenylethyl group). , 1-carboxy-2-hydroxy-phenylethyl group, 4-carboxybenzyl group, etc. And a cycloalkyl group (for example, a carboxy group such as a cyclohexyl group or a 4-carboxycyclohexyl group, a cyclohexyl group substituted with a hydroxyl group, etc.) or a hetero group. Cyclic groups (eg, pyridyl group, thiadiazolyl group, benzothiazolyl group, 2,2,6,6-tetramethylpiperidinyl group and other nitrogen atoms, 5-membered to 6-membered rings containing 1-2 sulfur atoms, or the like. And condensed rings such as a benzene ring and the like, each of which may be substituted with an alkyl group, a carboxyl group or the like). However, R ₈ does not represent a substituted triazinyl group.

The dye used in the present invention may be used as it is in the free acid form represented by the above general formula [I], [II] or [III], but when it is obtained in a salt form at the time of production, etc. For this, it may be used as it is or converted into a desired salt form. In addition, some acid groups in one molecule of the dye may be in the salt form, and the salt form dye and the free acid form dye may be used in combination. Examples of such a salt form include a salt form of an alkali metal such as sodium, lithium and potassium, an ammonium salt form which may be substituted with an alkyl group or a hydroxyalkyl group, and a salt form of an organic amine. Examples of the organic amine include lower alkylamine, hydroxy-substituted lower alkylamine, carboxy-substituted lower alkylamine, polyamine having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms, and the like. In the case of the above salt form, the type of salt is not limited to one type, and a plurality of types may be mixed.

In the present invention, the above general formulas [I] and [I
The dye represented by I] or [III] is, for example, A, C or E.
Represents a phenyl group having 1 to 2 substituents or a naphthalene group having 1 to 2 substituents, and B, D, and F each have a substituent at the 2-position and / or 5-position in the case of a phenylene group. 1,4-phenylene group is preferable, and when B, D and F are naphthylene groups, 1,4-phenylene group optionally having substituent (s)
A naphthylene group is preferred. The general formulas [I] and [II]
At

[0010]

[Chemical 2]

The group of is particularly the 6-position of naphtholsulfonic acid.
Or it is better to substitute at the 7-position, R ₁And R₂, R₃When
R_Four, R_FiveAnd R₆It is good that one of the two is H. Furthermore, R
₁, R ₂, R₃And R_FourOf which is not H, at least 1
Two groups and R_FiveAnd R₆The non-H group is COOH
It is preferably a substituted group. Furthermore R₈Is H or hydroxyl
Alternatively, it may be a group substituted with COOH. The above
Specific examples of the dyes represented by the general formulas [I], [II] and [III]
For example, the following No. Azo series having structures shown in 1 to 32
Dyes, these colors to obtain the desired shade
The elements may be used alone or in combination.

[0012]

[Chemical 3]

[0013]

[Chemical 4]

[0014]

[Chemical 5]

[0015]

[Chemical 6]

[0016]

[Chemical 7]

[0017]

[Chemical 8]

[0018]

[Chemical 9]

Among these compounds, the above general formula [II]
The compound represented by is excellent in water resistance and excellent in light resistance, and thus can be preferably used in the recording liquid of the present invention. Further, the compound represented by the general formula [I] is
It is particularly excellent in water resistance and is particularly preferable for the recording liquid of the present invention. The compounds represented by the general formulas [I], [II] and [III] can be produced according to a method known per se. For example, the above No. The dye represented by 1 can be produced by the following steps (A) to (D).

(A) A conventional method from 3-aminobenzoic acid and 2,5-diethoxyaniline [for example, Yutaka Hosoda, "New Dye Chemistry" (December 21, 1973, published by Gihodo, No. 39)
Page 6-409], a monoazo compound is produced through a diazotization and a coupling step. (B) The monoazo compound obtained in (A) is treated with 7-amino-
A disazo compound is produced from 1-hydroxy-3-naphthalenesulfonic acid (γ acid) by a conventional method through a diazotization and a coupling step. (C) The disazo compound obtained in (B) is added to a cyanuric chloride suspension while maintaining pH 4 to 6 and temperature 0 to 5 ° C, and the reaction is carried out for several hours. Next, at room temperature, a 3-aminobenzoic acid aqueous solution is added so as not to become alkaline, and a condensation reaction is carried out for several hours. Next, 50-n-hexylamine solution is added.
The mixture is added at 60 ° C. and a condensation reaction is carried out for several hours to complete the reaction. (D) The reaction solution obtained in (C) was cooled and then salted out with 20% saline to obtain the desired No. A dye of 1 is obtained.

As the carbon black used in the recording liquid of the present invention, commercially available general products can be used.
The primary particle size is 10 to 100 nm, and the DBP oil absorption is 4
A substance having a particle size of 0 to 150 ml / 100 g and a pH of 3 to 9 is preferable, but a substance having a primary particle diameter of 10 to 50 nm and a DBP oil absorption of 50 to 130 ml / 100 g is particularly preferable.
Specifically, products # 10, # 30 manufactured by Mitsubishi Kasei Co., Ltd.
# 33, # 40, # 42, # 45, # 48, # 52, #
95, # 2600, MA7, MA8, MA11, MA1
00, MA230, MA600 and the like.

The aqueous medium used in the recording liquid of the present invention is mainly water, but it is preferable to use a water-soluble organic solvent added to water. As the water-soluble organic solvent, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (# 200, # 400), glycols such as glycerin, alkyl ethers of the above glycols, N-methylpyrrolidone, Lower alcohols such as 1,3-dimethylimidazolinone, thiodiglycol, 2-pyrrolidone, sulfolane, dimethylsulfoxide, diethanolamine, triethanolamine, ethanol and isopropanol can be mentioned.

In the recording liquid of the present invention, it is preferable to use a dispersant in addition to the above components. Examples of the dispersant include various anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, polymeric dispersants and the like. Fatty acid salts as anionic surfactants,
Alkyl sulfate ester salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, alkyl phosphates, polyoxyethylene alkyl sulfate ester salts, polyoxyethylene alkyl allyl sulfate ester salts, alkanes Examples thereof include sulfonates, naphthalene sulfonate formalin condensates, polyoxyethylene alkyl phosphates, and α-olefin sulfonates. Nonionic surfactants include polyoxyethylene aryl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene derivatives, oxyethylene, oxypropylene block copolymers, sorbitan fatty acid esters, Polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters,
Examples thereof include polyoxyethylene alkylamines.
Examples of the cationic surfactant and the amphoteric surfactant include alkylamine salts, quaternary ammonium salts, alkylbetaines and aminoxides. As the polymer dispersant, polyacrylic acid, styrene / acrylic acid copolymer, styrene / acrylic acid / acrylic acid ester copolymer, styrene / (anhydrous) maleic acid copolymer, styrene / (anhydrous) maleic acid Acid / acrylic acid ester copolymer, styrene / methacrylic acid copolymer, styrene / methacrylic acid / acrylic acid ester copolymer, threthin / (anhydrous) maleic acid half ester copolymer, vinylnaphthalene / (anhydrous) maleic acid Examples thereof include copolymers, vinylnaphthalene / acrylic acid copolymers and salts thereof. In addition, (anhydrous) maleic acid represents maleic anhydride or maleic acid. Among these, anionic surfactants, nonionic surfactants and polymer dispersants are particularly excellent.

In addition to the above components, a water-soluble resin, a fungicide, a bactericide, a pH adjuster, urea and the like may be added to the recording liquid of the present invention as required. The method for preparing the recording liquid of the present invention is carried out by mixing the above-mentioned respective components and grinding and dispersing carbon black into fine particles using a disperser. A ball mill, a roll mill, a sand grind mill, or the like is used as the disperser, and a sand grind mill is particularly preferable. After milling and dispersion treatment, coarse particles are removed using a filter or a centrifuge. The particle size of carbon black is preferably adjusted to 1 μm or less. Components other than carbon black, a dispersant, and water may be added after milling and dispersion treatment. In addition, since grinding and dispersion treatment can be efficiently performed by preparing carbon black at a high concentration, the treatment liquid prepared at a high concentration is finally diluted with an aqueous medium to adjust the concentration of the recording liquid. Preferably.

Carbon black is usually used in an amount of 1 to 1 with respect to the recording liquid.
It is used in the range of 10% by weight, preferably 3 to 8% by weight. The dispersant is usually 5 to 100 relative to carbon black.
It is used in the range of 20% by weight, preferably 20 to 50% by weight. The amount of water-soluble organic solvent used in the recording liquid is usually 5 to 30.
It is in the range of 10% by weight but preferably 10 to 20% by weight. The content of the dyes represented by the general formulas [I], [II] and [III] in the recording liquid is usually 0.5 to 5% by weight, particularly 2 to 4% by weight based on the total amount of the recording liquid. Is preferred, and usually 10 to 300% by weight, particularly 30 to 100% by weight is preferred with respect to carbon black. Within these ranges, the addition amount may be changed according to the desired color tone. These carbon blacks, general formulas [I] and [II]
The compounds [III], the dispersant, and the organic solvent may be used alone, but in some cases, two or more of them may be used in combination to further enhance the effect.

[0026]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples unless the gist thereof is exceeded. In the following, "part" means "part by weight". Example 1 (Preparation of recording liquid)

[0027]

[Table 1] Composition of recording liquid Amount used (part) Glycerin 16 Ethylene glycol 18 Liporan PB-800 3 (trade name, α-olefin sulfonic acid sodium salt-based anionic surfactant, product of Lion Corporation) Carbon black MA100 11 (Mitsubishi Kasei Co., Ltd. product; primary particle diameter 22 nm, specific surface area 134 m ² / g, DBP oil absorption 100 ml / 100 g, pH 3.5). Dye of (1) 6 Ion-exchanged water 46 ─────────────────────────────────── Total 100

The above components were placed in a stainless steel container and crushed for 60 hours with a sand grinder together with 152 parts of glass beads having an average diameter of 0.5 mm.
The obtained liquid was diluted with 127 parts of ion-exchanged water and stirred, and then No. Pressure filtration was performed using 5C filter paper, and the liquid obtained here was used as a recording liquid. (Printing test) An inkjet printer (a product of Hewlett-Packard Company, trade name DeskJet 1200) was prepared by using the recording liquid obtained by the method described in the above example.
C) electrophotographic paper (Xerox 4024 paper, Xer
As a result of inkjet recording on the (ox product), stable and good dischargeability was obtained without clogging, and a printed matter with good print quality was obtained. The color tone of the obtained print is a spectroscopic color difference meter (trade name, SZ-Σ80, Nippon Denshoku Industries Co., Ltd.)
Product). As a result, as shown in Table 1 below, the color tone was bluish black, which was preferable as the black color tone.

(Water resistance test) The printed matter obtained in the printing test was immersed in tap water in a beaker for 5 seconds. After the printed matter was dried, the presence or absence of stains was visually evaluated. The results are classified as follows and shown in Table 1 below.

[0030]

[Table 2] ○ ……… Almost no character stains △ ……… Slightly dirty, but practically no problem × ……… The character is very dirty.

(Light resistance test) The printed matter was visually evaluated for discoloration and fading after irradiation for 100 hours using a xenon fade meter (product of Suga Test Instruments Co., Ltd.). The results are classified as follows and shown in Table 1 below.

[0032]

[Table 3] ○ ……… Good △ ……… Discoloration and fading, but practically no problem × ……… Discoloration is severe

(Storage stability test of recording liquid) The recording liquid was sealed in a Teflon container and stored at 60 ° C for 1 month. The presence or absence of gelation and precipitate was visually evaluated. The results are classified as follows and shown in Table 1 below.

[0034]

[Table 4] ○ ……… Almost no gelation or precipitate △ ……… A slight gelation or precipitate is seen, but there is no problem in practical use × ……… Gelling or precipitate is severe

Example 2 (Preparation of recording liquid)

[0036]

[Table 5] Composition of recording liquid Amount used (part) Glycerin 16 Ethylene glycol 18 Polystar S2-1020 (nonvolatile matter) 3 (trade name, styrene / maleic anhydride copolymer (anionic surfactant) NOF Products) Carbon black MA8 11 (Mitsubishi Kasei product; primary particle size 24 nm, specific surface area 137 m ² / g, DBP oil absorption 58 ml / 100 g, pH 3.0). Dye of (3) 6 Ion-exchanged water 46 ─────────────────────────────────── Total 100

Each of the above components was placed in a stainless steel container, and crushed for 60 hours using a sand grinder together with 152 parts of glass beads having an average diameter of 0.5 mm.
The obtained liquid was diluted with 127 parts of ion-exchanged water and stirred, and then No. Pressure filtration was performed using 5C filter paper, and the liquid obtained here was used as a recording liquid. The printing test, the water resistance test, the light resistance test, the storage stability test, and the evaluation were performed in the same manner as in Example 1. The color tone of the printed matter was a bluish black which was preferable. The evaluation results are shown in Table 1 below. Example 3 (Preparation of recording liquid)

[0038]

[Table 6] Composition of recording liquid Amount used (part) Glycerin 16 Ethylene glycol 18 Penerol NP-50 3 (trade name; polyoxyethylene alkylaryl ether nonionic surfactant Matsumoto Yushi Co., Ltd. product) Carbon black MA230 11 (product of Mitsubishi Kasei Co., Ltd .; primary particle size 30 nm, specific surface area 70 m ² / g, DBP oil absorption 113 ml / 100 g, pH 3.0). Dye of (22) 6 Ion-exchanged water 46 ─────────────────────────────────── Total 100

Each of the above components was placed in a stainless steel container and crushed for 60 hours using a sand grinder together with 152 parts of glass beads having an average diameter of 0.5 mm.
The obtained liquid was diluted with 127 parts of ion-exchanged water and stirred, and then No. Pressure filtration was performed using 5C filter paper, and the liquid obtained here was used as a recording liquid. The printing test, the water resistance test, the light resistance test, the storage stability test, and the evaluation were performed in the same manner as in Example 1. The color tone of the printed matter was a bluish black which was preferable. The evaluation results are summarized in Table 1 below. Example 4 (Preparation of recording liquid)

[0040]

[Table 7] Composition of recording liquid Amount used (part) Glycerin 16 Ethylene glycol 18 Polystar S2-1020 (nonvolatile) 3 Carbon black # 45 11 (Mitsubishi Kasei Co., Ltd. product; primary particle diameter 24 nm, specific surface area 125 m ² / G, DBP oil absorption amount 53 ml / 100 g, pH 8.0). Dye of (27) 6 Ion-exchanged water 46 ─────────────────────────────────── Total 100

Each of the above components was placed in a stainless steel container and pulverized with 152 parts of glass beads having an average diameter of 0.5 mm for 60 hours using a sand grinder.
The obtained liquid was diluted with 127 parts of ion-exchanged water and stirred, and then No. Pressure filtration was performed using 5C filter paper, and the liquid obtained here was used as a recording liquid. The printing test, the water resistance test, the light resistance test, the storage stability test, and the evaluation were performed in the same manner as in Example 1. The color tone of the printed matter was a bluish black which was preferable. The evaluation results are shown in Table 1 below. Example 5 (Preparation of recording liquid)

[0042]

[Table 8] Composition of recording liquid Amount used (part) Glycerin 16 Ethylene glycol 18 Lipolan PB-800 3 Carbon black # 30 11 (Mitsubishi Kasei Co., Ltd. product; primary particle diameter 30 nm, specific surface area 85 m ² / g, DBP Oil absorption 113 ml / 100 g, pH 8.0) Said No. Dye of (11) 6 Ion-exchanged water 46 ─────────────────────────────────── Total 100

The above components were placed in a stainless steel container and crushed for 60 hours with a sand grinder together with 152 parts of glass beads having an average diameter of 0.5 mm.
The obtained liquid was diluted with 127 parts of ion-exchanged water and stirred, and then No. Pressure filtration was performed using 5C filter paper, and the liquid obtained here was used as a recording liquid. The printing test, the water resistance test, the light resistance test, the storage stability test, and the evaluation were performed in the same manner as in Example 1. The color tone of the printed matter was a bluish black which was preferable. The evaluation results are shown in Table 1 below.

[0044]

[Table 9]

[0045]

EFFECT OF THE INVENTION By using the ink jet recording liquid of the present invention, it is possible to perform recording with good dischargeability and high reliability, good water resistance when recorded on plain paper, and a bluish tint with a favorable color tone. With black, it is possible to obtain a black recorded matter having a high recording density and good fastness other than water resistance such as print quality and light resistance. Since the present invention has the above-mentioned characteristics, it is not limited to ink jet and writing instruments, and can be used as a recording liquid for other purposes.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Yamada 1000 Kamoshita-cho, Midori-ku, Yokohama-shi, Kanagawa Mitsubishi Kasei Research Institute (72) Inventor Hiro Takimoto 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Mitsubishi Kasei (56) Reference JP-A-2-276873 (JP, A) JP-A-4-59879 (JP, A) JP-A-2-276875 (JP, A) JP-A-4-57862 ( JP, A) Yutaka Hosoda, New Dye Chemistry, Gihodo Co., Ltd., August 1, 1965, 3rd edition, p. 128, Organic Synthetic Chemistry Association of Japan, New Edition Dyeing Handbook, October 30, 1974. , P. 34 (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 B41J 2/01-2/21 B41M 5/00 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. An aqueous medium, carbon black and a free acid form containing at least one selected from the group consisting of compounds represented by the following general formula [I], [II] or [III]. Recording liquid. [Chemical 1] [In the formula, A, C and E each independently represent a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group, and B, D and F are each independently a substituted or unsubstituted phenylene group or a substituted or unsubstituted phenylene group. Shows unsubstituted naphthylene groups
You R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 1 to 18 carbon atoms, or an aryl group. , An aralkyl group, a cycloalkyl group, or a heterocyclic group (provided that R ₈ does not represent a triazinyl group having a substituent), and these groups may have a substituent. However, the compound
The number of sulfonic acid groups of [I] to [ III ] is 1 to 3.
It The compound [I] contains at least one of A, R ₁ , R ₂ , R ₃ and R ₄ .
A carboxylic acid group is present in the compound [ II ] and at least one of C, R ₅ and R ₆ is a carboxylic acid group.
Groups are present, the compound [III] when less of E and R ₈
On the other hand, there is a carboxylic acid group. ] 2. A compound represented by the general formula [ II ] according to claim 1, wherein the aqueous medium, carbon black and the free acid form are
And a carboxylic acid group is present on one of R ₅ and R _6.
A recording liquid containing at least one compound selected from the following . 3. A compound represented by the general formula [I] according to claim 1, wherein the aqueous medium, carbon black and the free acid form are the same.
And at least one of R _{1 to} R ₄ has a carboxylic acid group.
A recording liquid containing at least one kind of compound present .