JP5256732B2 - Ink jet recording ink, ink cartridge, and ink jet recording apparatus - Google Patents

Description

  The present invention relates to an ink for ink jet recording, an ink cartridge, and an ink jet recording apparatus.

  Conventionally, inks containing dyes, dipropylene glycol propyl ether, acetylene glycol surfactants, and the like are known as inks for inkjet recording (see, for example, Patent Document 1). The ink has (1) excellent color developability, (2) excellent jet stability even after long-term use, (3) excellent print quality, and (4) ink jet. It is required that the compound derived from the material forming the recording apparatus is prevented from eluting into the ink, and (5) the recorded matter has excellent fastness such as light resistance and ozone resistance. However, none of the conventional inks satisfy all the above performances. Examples of the material forming the ink jet recording apparatus include a rubber member and an organic material member other than the rubber material. Examples of the rubber member include a wiper and a cap. For example, the wiper wipes the nozzle surface of the inkjet head. For example, the cap blocks the nozzle surface and the outside world. When the compound derived from the rubber member or the like elutes into the ink, the compound may precipitate in the ink. When the compound is precipitated, for example, the nozzle of the inkjet head may be clogged.

Japanese Patent Laid-Open No. 9-111165

  Therefore, the present invention is excellent in color developability, jetting stability and print quality, prevents elution of a compound derived from a rubber member or the like in an ink jet recording apparatus into ink, and is excellent in fastness of recorded matter. An object of the present invention is to provide an ink for inkjet recording.

前記一般式（１）において、
Ｒ_１は、水素原子、置換または無置換のアルキル基、置換または無置換のアリール基であり、
Ｒ_２は、水素原子、ハロゲン原子またはシアノ基であり、
Ｒ_３は、水素原子、置換または無置換のアルキル基、置換または無置換のアリール基、置換または無置換のヘテロ環基であり、
Ｒ_４、Ｒ_５、Ｒ_６およびＲ_７は、それぞれ、水素原子、置換または無置換のアルキル基、置換または無置換のアリール基、置換または無置換のヘテロ環基、置換または無置換のスルホニル基、置換または無置換のアシル基であり、Ｒ_４、Ｒ_５、Ｒ_６およびＲ_７は同一でも異なっていてもよいが、Ｒ_４とＲ_５が共に水素原子であることはなく、Ｒ_６とＲ_７が共に水素原子であることはなく、
Ａ_１およびＡ_２は、双方が置換または無置換の炭素原子であるか、若しくは一方が置換または無置換の炭素原子であり、且つ、他方が窒素原子である。

前記一般式（２）において、
Ｒ_８、Ｒ_９およびＲ_１０は、それぞれ、置換または無置換のアルキル基、置換または無置換のアルコキシ基、ハロゲン原子、水素原子、ヒドロキシル基、置換または無置換のカルバモイル基、置換または無置換のスルファモイル基、置換または無置換のアミノ基、ニトロ基、スルホン酸エステル基、置換または無置換のアルキルスルホニル基、置換または無置換のアリールスルホニル基、カルボキシル基、カルボン酸エステル基であり、Ｒ_８、Ｒ_９およびＲ_１０は同一でも異なっていてもよく、
ｋは、０、１または２であり、
Ｒ_１１、Ｒ_１２およびＲ_１３は、それぞれ、水素原子、置換または無置換のアルキル基、置換または無置換のアルケニル基、置換または無置換のアリール基、置換または無置換のアラルキル基、置換または無置換の脂環基、置換または無置換のヘテロ環基であり、Ｒ_１１、Ｒ_１２およびＲ_１３は同一でも異なっていてもよい。

前記一般式（３）において、ｍおよびｎは同一でも異なっていてもよく、ｍ＋ｎ＝１〜１５を満たす数であり、
Ｒ_２１、Ｒ_２２、Ｒ_２３およびＲ_２４は、それぞれ同一でも異なっていてもよく、炭素原子数１〜５の直鎖状または分岐鎖状アルキル基である。
In order to achieve the above object, the inkjet recording ink of the present invention comprises:
An ink for ink jet recording comprising a colorant, water, a water-soluble organic solvent, and an acetylene glycol surfactant,
The colorant includes the following dye (1) and dye (2),
The water-soluble organic solvent comprises dipropylene glycol propyl ether;
The acetylene glycol-based surfactant contains a surfactant represented by the following general formula (3),
The surfactant represented by the dye (1), the dye (2), the dipropylene glycol propyl ether, and the general formula (3) satisfy the following conditions (A) to (D), respectively. It is characterized by being blended.
Dye (1): Dye dye represented by the following general formula (1) (2): Dye whose free acid is represented by the following general formula (2)
(A) The total amount of the dye (1) and the dye (2) is 2 to 5% by weight based on the total amount of the ink.
(B) The weight ratio of the dye (1) and the dye (2) in the ink is dye (1): dye (2) = 9: 1 to 7: 3
(C) 0.5 ≦ x ≦ 2.5
(D) 1 ≦ y ≦ 3
(E) y ≧ −2x + 3 and y ≦ −2x + 6
x: blending amount (wt%) of the surfactant represented by the general formula (3) with respect to the total amount of the ink
y: blending amount of dipropylene glycol propyl ether with respect to the total amount of ink (% by weight)

In the general formula (1),
R ₁ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group,
R ₂ is a hydrogen atom, a halogen atom or a cyano group,
R ₃ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group,
R ₄ , R ₅ , R ₆ and R ₇ are each a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted sulfonyl group A substituted or unsubstituted acyl group, and R ₄ , R ₅ , R ₆ and R ₇ may be the same or different, but R ₄ and R ₅ are not both hydrogen atoms, and R ₆ and R ₇ is not both a hydrogen atom,
A ₁ and A ₂ are both substituted or unsubstituted carbon atoms, or one is a substituted or unsubstituted carbon atom and the other is a nitrogen atom.

In the general formula (2),
R ₈ , R ₉ and R ₁₀ are each a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a halogen atom, a hydrogen atom, a hydroxyl group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted group A sulfamoyl group, a substituted or unsubstituted amino group, a nitro group, a sulfonic acid ester group, a substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group, a carboxyl group, a carboxylic acid ester group, R ₈ , R ₉ and R ₁₀ may be the same or different,
k is 0, 1 or 2;
R ₁₁ , R ₁₂ and R ₁₃ are each a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, substituted or unsubstituted A substituted alicyclic group, a substituted or unsubstituted heterocyclic group, and R ₁₁ , R ₁₂ and R ₁₃ may be the same or different;

In the general formula (3), m and n may be the same or different, and are numbers satisfying m + n = 1 to 15,
R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ may be the same or different and each is a linear or branched alkyl group having 1 to 5 carbon atoms.

As a result of a series of studies, the present inventors have found that the ink containing the dye is represented by the dye (1), the dye (2), the dipropylene glycol propyl ether, and the general formula (3). If a surfactant is blended so as to satisfy the above conditions (A) to ( E ), it is excellent in color developability, jetting stability and print quality, and into a compound ink derived from a rubber member or the like in an ink jet recording apparatus. Was found to be prevented, and the fastness of the recorded matter was also found, leading to the present invention.
Such an improvement in performance has been found for the first time by the present inventors.
The mechanism by which the ink of the present invention is excellent in all of the above performances is assumed as follows, for example.
The dye (1) is excellent in fastness, while the dye (2) is excellent in color development.
However, the ink containing the dye has a problem in ejection stability when used for a long period of time, for example.
In contrast, the ink of the present invention is formulated so that the dipropylene glycol propyl ether and the surfactant represented by the general formula (3) satisfy the conditions (C) to (E) . Even when used for a long period of time, the jetting stability is excellent, the printing quality is excellent, and further, the elution of the compound derived from the rubber member or the like in the ink jet recording apparatus into the ink is prevented.
These performance improvement mechanisms are speculations and do not limit the present invention.

  The use of the inkjet recording ink of the present invention is not particularly limited, and for example, it can be used as a magenta ink. However, the present invention is not limited to this. The ink for ink jet recording of the present invention can be made into ink of a color other than magenta by using a colorant other than the dye.

  The ink cartridge of the present invention is an ink cartridge containing ink for ink jet recording, and the ink is the ink for ink jet recording of the present invention.

  The ink jet recording apparatus of the present invention is an ink jet recording apparatus that includes an ink cartridge and an ink discharge means, and ink for ink jet recording is discharged from the ink discharge means, and the ink cartridge is the ink cartridge of the present invention. It is characterized by that.

  Next, the inkjet recording ink of the present invention will be described. The ink of the present invention contains a colorant, water, a water-soluble organic solvent, and an acetylene glycol surfactant. As described above, the colorant includes the dye (1) and the dye (2).

  As described above, the dye (1) is a dye represented by the general formula (1).

As described above, in the general formula (1),
R ₁ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group,
R ₂ is a hydrogen atom, a halogen atom or a cyano group,
R ₃ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group,
R ₄ , R ₅ , R ₆ and R ₇ are each a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted sulfonyl group A substituted or unsubstituted acyl group, and R ₄ , R ₅ , R ₆ and R ₇ may be the same or different, but R ₄ and R ₅ are not both hydrogen atoms, and R ₆ and R ₇ is not both a hydrogen atom,
A ₁ and A ₂ are both substituted or unsubstituted carbon atoms, or one is a substituted or unsubstituted carbon atom and the other is a nitrogen atom.

  In the general formula (1), examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  In the general formula (1), the substituted or unsubstituted alkyl group is preferably an alkyl group having 1 to 6 carbon atoms. Examples of the substituted or unsubstituted alkyl group include a methyl group, ethyl group, n-butyl group, isopropyl group, tert-butyl group, hydroxyethyl group, methoxyethyl group, cyanoethyl group, trifluoromethyl group, 3- Examples thereof include a sulfopropyl group and a 4-sulfobutyl group. Examples of the substituent of the substituted alkyl group include hydroxyl group; alkoxy group such as methoxy group and ethoxy group; cyano group; halogen atom such as fluorine atom, chlorine atom, bromine atom and iodine atom; carboxylate salt and sulfonic acid Examples thereof include ionic hydrophilic groups such as salts.

  In the general formula (1), the substituted or unsubstituted aryl group is preferably an aryl group having 6 to 12 carbon atoms. However, in the case of a substituted aryl group, the number of carbon atoms does not include the number of carbon atoms of the substituent. Examples of the substituted or unsubstituted aryl group include phenyl group, naphthyl group, p-tolyl group, p-octylphenyl group, mesityl group, p-methoxyphenyl group, o-chlorophenyl group, m- (3-sulfo group). Propylamino) phenyl group and the like. Examples of the substituent of the substituted aryl group include an alkyl group such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, and an n-octyl group; an alkoxy group similar to the above; a halogen atom similar to the above; Alkylamino groups such as amino groups and dimethylamino groups; Amido groups; Carbamoyl groups; Sulfamoyl groups; Sulfamide groups; Hydroxyl groups; Ester groups such as methoxycarbonyl groups and ethoxycarbonyl groups; It is done.

  In the general formula (1), the substituted or unsubstituted heterocyclic group is preferably a 5-membered or 6-membered heterocyclic group. Examples of the substituted or unsubstituted heterocyclic group include 2-pyridyl group, 2-thienyl group, 2-thiazolyl group, 2-benzothiazolyl group, 2-furyl group, 6-sulfobenzothiazolyl group, 6 -A sulfonate benzothiazolyl group and the like. Examples of the substituent of the substituted heterocyclic group include an amide group; a carbamoyl group; a sulfamoyl group; a sulfoamide group; a hydroxyl group; an ester group as described above; and an ionic hydrophilic group as described above.

  In the general formula (1), examples of the substituted or unsubstituted sulfonyl group include a methylsulfonyl group and a phenylsulfonyl group. Examples of the substituent of the substituted sulfonyl group include a substituted or unsubstituted alkyl group similar to the above, a substituted or unsubstituted aryl group similar to the above.

  In the general formula (1), the substituted or unsubstituted acyl group is preferably an acyl group having 1 to 12 carbon atoms. However, in the case of a substituted acyl group, the number of carbon atoms does not include the number of carbon atoms of the substituent. Examples of the substituted or unsubstituted acyl group include an acetyl group, a benzoyl group, and a chloroacetyl group. Examples of the substituent of the substituted acyl group include the same ionic hydrophilic groups as described above.

In the general formula (1), as described above, A ₁ and A ₂ are both substituted or unsubstituted carbon atoms, or one is a substituted or unsubstituted carbon atom and the other is nitrogen. Is an atom. The case where both A ₁ and A ₂ are carbon atoms is preferable in that it can exhibit more excellent performance. Examples of the substituent bonded to a carbon atom of A ₁ and A _2, for example, an alkyl group having 1 to 3 carbon atoms, a carboxyl group, a carbamoyl group, a cyano group, and the like.

As described above, in the general formula (1), R ₄ and R ₅ are not both hydrogen atoms, and R ₆ and R ₇ are not both hydrogen atoms. Moreover, in the said General formula (1), when the substitution number of a sulfonic acid group or a carboxyl group increases, there exists a tendency for the water solubility of the said dye to improve, Therefore It is preferable to adjust those substitution numbers as needed.

As a preferable embodiment of the dye (1), for example, in the general formula (1), R ₁ is an alkyl group, R ₂ is a cyano group, R ₃ is a hydrogen atom or a substituted or unsubstituted heterocyclic group, R ₄ Is a hydrogen atom, a substituted or unsubstituted heterocyclic group or substituted aryl group, R ₅ and R ₆ are each a substituted heterocyclic group or a substituted aryl group, R ₇ is a hydrogen atom, and A ₁ is substituted An embodiment in which the carbon atom, A ₂ is a substituted or unsubstituted carbon atom is exemplified.

As a more preferable embodiment of the dye (1), for example, in the general formula (1), R ₁ is a tert-butyl group, R ₂ is a cyano group, R ₃ is a hydrogen atom, a sulfonic acid group or an alkali metal base thereof. Benzothiazolyl group (preferably benzothiazol-2-yl group) which may be substituted with R ₄ , a benzothiazolyl group (preferably benzothiazole-yl group) which may be substituted with a hydrogen atom, a sulfonic acid group or an alkali metal base thereof. 2-yl group) or a trialkylphenyl group (preferably a mesityl group) substituted with a sulfonic acid group or an alkali metal base thereof, and R ₅ and R ₆ are each substituted with a sulfonic acid group or an alkali metal base thereof. A mono-, di- or trialkylphenyl group (preferably p-octylphenol) Is a benzothiazolyl group (preferably substituted with Le group or a mesityl group) or a sulfonic acid group or alkali metal bases, benzothiazol-2-yl group), R ₇ is a hydrogen atom, A ₁ is an alkyl group (preferably Is a carbon atom substituted with a methyl group), and A ₂ is a carbon atom optionally substituted with a cyano group.

  Preferable specific examples of the dye (1) include compounds represented by the following chemical formulas (1-A) to (1-F).

In the compound represented by the chemical formula (1-A), in the general formula (1), R ₁ is a tert-butyl group, R ₂ is a cyano group, R ₃ is a benzothiazol-2-yl group, and R ₄ is A hydrogen atom, R ₅ and R ₆ are p-octylphenyl groups, R ₇ is a hydrogen atom, A ₁ is a carbon atom substituted with a methyl group, and A ₂ is a carbon atom substituted with a cyano group It is an aspect.

In the compound represented by the chemical formula (1-B), in the general formula (1), R ₁ is a tert-butyl group, R ₂ is a cyano group, R ₃ and R ₄ are benzothiazol-2-yl groups, In this embodiment, R ₅ and R ₆ are mesityl groups, R ₇ is a hydrogen atom, A ₁ is a carbon atom substituted with a methyl group, and A ₂ is a carbon atom.

The compound represented by the chemical formula (1-C) is the compound represented by the general formula (1) in which R ₁ is a tert-butyl group, R ₂ is a cyano group, R ₃ and R ₄ are 6-sulfosodium salt benzothiazole- A mode in which 2-yl group, R ₅ and R ₆ are 3-sulfosodium salt-mesityl group, R ₇ is a hydrogen atom, A ₁ is a carbon atom substituted with a methyl group, and A ₂ is a carbon atom is there.

In the compound represented by the chemical formula (1-D), in the general formula (1), R ₁ is a tert-butyl group, R ₂ is a cyano group, R ₃ and R ₄ are 6-sulfolithium salt benzothiazole- A carbon atom in which a 2-yl group, R ₅ and R ₆ are 2,6-diethyl-4-methyl-3-sulfolithium phenyl group, R ₇ is a hydrogen atom, and A ₁ is substituted with a methyl group, In this embodiment, A ₂ is a carbon atom.

In the compound represented by the chemical formula (1-E), in the general formula (1), R ₁ is a tert-butyl group, R ₂ is a cyano group, R ₃ and R ₄ are 6-sulfo potassium salt benzothiazole- A mode in which 2-yl group, R ₅ and R ₆ are 3-sulfo potassium salt-mesityl group, R ₇ is a hydrogen atom, A ₁ is a carbon atom substituted with a methyl group, and A ₂ is a carbon atom is there.

The compound represented by the chemical formula (1-F) is the compound represented by the general formula (1), in which R ₁ is a tert-butyl group, R ₂ is a cyano group, R ₃ and R ₄ are 6-sulfolithium benzothiazole- 2-yl group, R ₅ and R ₆ are 2,6-diethyl-4-sulfolithium phenyl groups, R ₇ is a hydrogen atom, A ₁ is a carbon atom substituted with a methyl group, and A ₂ is carbon This is an embodiment that is an atom.

  The blending amount of the dye (1) is not particularly limited as long as it is within a range satisfying the conditions (A) and (B). By including the dye (1) in the ink, the fastness of the recorded matter using the ink can be improved. The blending amount of the dye (1) is, for example, 1.4 to 4.5% by weight, preferably 1.75 to 4.05% by weight, based on the total amount of the ink.

  As described above, the dye (2) is a dye whose free acid is represented by the general formula (2).

As described above, in the general formula (2),
R ₈ , R ₉ and R ₁₀ are each a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a halogen atom, a hydrogen atom, a hydroxyl group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted group A sulfamoyl group, a substituted or unsubstituted amino group, a nitro group, a sulfonic acid ester group, a substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group, a carboxyl group, a carboxylic acid ester group, R ₈ , R ₉ and R ₁₀ may be the same or different,
k is 0, 1 or 2;
R ₁₁ , R ₁₂ and R ₁₃ are each a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, substituted or unsubstituted A substituted alicyclic group, a substituted or unsubstituted heterocyclic group, and R ₁₁ , R ₁₂ and R ₁₃ may be the same or different;

In the general formula (2), the substituted or unsubstituted alkyl group in R ₈ , R ₉ and R ₁₀ is preferably an alkyl group having 1 to 9 carbon atoms in total. Examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a trifluoromethyl group, and a dimethylaminomethyl group. Examples of the substituent of the substituted alkyl group include the same substituents as the substituents of the substituted alkyl group of the dye (1) represented by the general formula (1).

In the general formula (2), the substituted or unsubstituted alkoxy group in R ₈ , R ₉ and R ₁₀ is preferably an alkoxy group having 1 to 9 carbon atoms in total. Examples of the substituted or unsubstituted alkoxy group include a methoxy group, an isopropoxy group, and an n-butoxy group.

In the general formula (2), examples of the halogen atom in R ₈ , R _9, and R ₁₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the general formula (2), examples of the substituted or unsubstituted carbamoyl group in R ₈ , R ₉ and R ₁₀ include a carbamoyl group, an N, N-dimethylcarbamoyl group, and a phenylcarbamoyl group.

In the general formula (2), examples of the substituted or unsubstituted sulfamoyl group in R ₈ , R ₉ and R ₁₀ include a sulfamoyl group, an N-methylsulfamoyl group, an N-ethylsulfamoyl group, an N— Examples thereof include an ethyl-N-phenylsulfamoyl group, an N, N-dimethylsulfamoyl group, and a p-carboxyphenylsulfamoyl group.

In the general formula (2), examples of the substituted or unsubstituted amino group in R ₈ , R ₉ and R ₁₀ include an N-methylamino group, a carbamoylamino group, an N, N-diethylamino group, and an acetylamino group. Can be given.

In the general formula (2), examples of the sulfonate group in R ₈ , R ₉ and R ₁₀ include a phenoxysulfonyl group.

In the general formula (2), the substituted or unsubstituted alkylsulfonyl group in R ₈ , R ₉ and R ₁₀ is preferably an alkylsulfonyl group having 1 to 9 carbon atoms in total. Examples of the substituted or unsubstituted alkylsulfonyl group include a hydroxyethylsulfonyl group.

In the general formula (2), the substituted or unsubstituted arylsulfonyl group in R ₈ , R ₉ and R ₁₀ is preferably an arylsulfonyl group having 6 to 15 total carbon atoms. Examples of the substituted or unsubstituted arylsulfonyl group include a benzylsulfonyl group.

In the general formula (2), examples of the carboxylic ester group in R ₈ , R ₉ and R ₁₀ include a methoxycarbonyl group.

In the general formula (2), the substituted or unsubstituted alkyl group in R ₁₁ , R ₁₂ and R ₁₃ is preferably an alkyl group having 1 to 18 carbon atoms in total. Examples of the substituted or unsubstituted alkyl group include an ethyl group, an n-butyl group, an n-octyl group, an ethylhexyl group, a hydroxyethyl group, a carboxypropyl group, a carboxycyclohexylmethyl group, and 1-carboxy-2-mercaptoethyl. Group, 1-carboxy-2-carbamoyl-ethyl group, 1-isopropyl-1-carboxymethyl group, 1,2-dicarboxypropyl group and the like. Examples of the substituent of the substituted alkyl group include the same substituents as the substituents of the substituted alkyl group of the dye (1) represented by the general formula (1).

In the general formula (2), the substituted or unsubstituted alkenyl group in R ₁₁ , R ₁₂ and R ₁₃ is preferably an alkenyl group having 2 to 18 carbon atoms in total. Examples of the substituted or unsubstituted alkenyl group include 2-methyl-1-propenyl group, vinyl group, allyl group and the like.

In the general formula (2), examples of the substituted or unsubstituted aryl group in R ₁₁ , R ₁₂ and R ₁₃ include a 3,4-dicarboxyphenyl group, a 4-butylphenyl group, and a 4-carboxyphenyl group. Can be given. Examples of the substituent of the substituted aryl group include the same substituents as the substituents of the substituted aryl group of the dye (1) represented by the general formula (1).

In the general formula (2), examples of the substituted or unsubstituted aralkyl group in R ₁₁ , R ₁₂ and R ₁₃ include benzyl group, 1-carboxy-2-phenyl-ethyl group, 1-carboxy-2-hydroxy group. Examples thereof include a phenylethyl group and a 4-carboxybenzyl group.

In the general formula (2), examples of the substituted or unsubstituted alicyclic group in R ₁₁ , R ₁₂ and R ₁₃ include a cyclohexyl group and a 4-carboxycyclohexyl group.

In the general formula (2), examples of the substituted or unsubstituted heterocyclic group in R ₁₁ , R ₁₂ and R ₁₃ include a pyridyl group, a thiadiazolyl group, a benzothiazolyl group, 2,2,6,6-tetramethylpi And a peridinyl group. Examples of the substituent of the substituted heterocyclic group include the same substituents as the substituents of the substituted heterocyclic group of the dye (1) represented by the general formula (1).

In the general formula (2), as R ₁₁ , R ₁₂ and R ₁₃ , at least one is an alkyl group, alkenyl group, aryl group, alicyclic group substituted with 1 to 4 carboxyl groups or sulfamoyl groups, It may be an aralkyl group or a heterocyclic group.

In the general formula (2), R ₁₁ and R ₁₂ may each be a hydrogen atom or a trisubstituted phenyl group, and R ₁₁ and R ₁₂ may be the same or different. Here, the three substituents of the 3-substituted phenyl group are each a hydrogen atom, a halogen atom, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 9 total carbon atoms, and a total number of 1 to 9 carbon atoms. A substituted or unsubstituted alkoxy group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a substituted or unsubstituted amino group, a nitro group, a sulfonic acid ester group, and a carboxylic acid ester group. The groups may be the same or different.

As a preferable embodiment of the dye (2), for example, in the general formula (2), at least one of R ₁₁ , R ₁₂ and R ₁₃ is an alkyl substituted with 1 to 4 carboxyl groups or sulfamoyl groups. And an alkenyl group, an aryl group, an aralkyl group, or a cyclohexyl group.

  The dye (2) preferably has a total of 6 or less, preferably 5 or less, particularly preferably 4 or less sulfonic acid groups and carboxyl groups or salts thereof in the structure. Moreover, although the said dye (2) may be used with a free acid form, when obtained with a salt form at the time of manufacture, you may use as it is and may convert into a desired salt form. The dye (2) may have a part of the acid group in a salt form, and may contain a salt-type dye and a free acid-type dye. Examples of such salt forms include salts of alkali metals such as Na, Li and K, ammonium salts which may be substituted with alkyl groups or hydroxyalkyl groups, and organic amine salts. Examples of the organic amine include lower alkyl amines, hydroxy substituted lower alkyl amines, carboxy substituted lower alkyl amines, and polyamines having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.

As a preferable embodiment of the dye (2), for example, in the general formula (2), k is 0, R ₈ is a carboxyl group, a carbamoyl group, a trifluoromethyl group, a sulfamoyl group, R ₉ and R _An embodiment in which ₁₀ is a hydrogen atom, R ₁₁ is a phenyl group or a carboxyalkyl group which may be substituted with a carboxyl group or a sulfamoyl group, R ₁₂ is a hydrogen atom, and R ₁₃ is a hydrogen atom or an alkyl group can give.

  Particularly preferred specific examples of the dye (2) include compounds represented by the following chemical formulas (2-A) to (2-E).

In the general formula (2), the compound represented by the chemical formula (2-A) is a carboxyl group located at the 2-position of the phenyl group in which k is 0 and R ₈ is bonded to the azo group, R ₉ , R ₁₀ And R ₁₂ is a hydrogen atom, R ₁₁ is a 2-carboxyphenyl group, and R ₁₃ is a hydrogen atom. In the compound represented by the chemical formula (2-A), the sulfonic acids located at the 3rd and 6th positions of the naphthalene ring are ammonium salts.

In the compound represented by the chemical formula (2-B), in the general formula (2), k is 0, and R ₈ is a carbamoyl group located at the 2-position of the phenyl group bonded to the azo group, R ₉ , R ₁₀ And R ₁₂ is a hydrogen atom, R ₁₁ is a 2-carboxyphenyl group, and R ₁₃ is a hydrogen atom. In the compound represented by the chemical formula (2-B), the sulfonic acids located at the 3rd and 6th positions of the naphthalene ring are sodium salts.

In the compound represented by the chemical formula (2-C), in the general formula (2), k is 0, and R ₈ is a sulfamoyl group located at the 3-position of the phenyl group bonded to the azo group, R ₉ , R ₁₀ And R ₁₂ is a hydrogen atom, R ₁₁ is a 2-sulfamoylphenyl group, and R ₁₃ is an isopropyl group. In the compound represented by the chemical formula (2-C), the sulfonic acids located at the 3rd and 6th positions of the naphthalene ring are ethylammonium salts.

The compound represented by the chemical formula (2-D) is a trifluoromethyl group located at the 2-position of the phenyl group in which k is 0 and R ₈ is bonded to the azo group in the general formula (2), R ₉ , In this embodiment, R ₁₀ and R ₁₂ are hydrogen atoms, R ₁₁ is a 1-carboxy-2-methylbutyl group, and R ₁₃ is a methyl group. In the compound represented by the chemical formula (2-D), the sulfonic acids located at the 3rd and 6th positions of the naphthalene ring are methylammonium salts.

In the general formula (2), the compound represented by the chemical formula (2-E) is a carboxyl group located at the 2-position of the phenyl group in which k is 0 and R ₈ is bonded to the azo group, R ₉ , R ₁₀ And R ₁₂ is a hydrogen atom, R ₁₁ is a phenyl group, and R ₁₃ is a hydrogen atom. In the compound represented by the chemical formula (2-E), the sulfonic acids located at the 3rd and 6th positions of the naphthalene ring are ammonium salts.

  The blending amount of the dye (2) is not particularly limited as long as it is within a range satisfying the conditions (A) and (B). By including the dye (2) in the ink, an ink having excellent color developability can be obtained. The blending amount of the dye (2) is, for example, 0.2 to 1.5% by weight, preferably 0.25 to 1.35% by weight, based on the total amount of the ink.

  As described above, the total amount of the dye (1) and the dye (2) is 2 to 5% by weight with respect to the total amount of the ink. The total blending amount is preferably 2.5 to 4.5% by weight.

  As described above, the weight ratio of the dye (1) to the dye (2) is dye (1): dye (2) = 9: 1 to 7: 3.

  The colorant may be composed only of the dye (1) and the dye (2), and may further contain other dyes or pigments.

  The water is preferably ion exchange water or pure water. The blending amount of the water with respect to the total amount of the ink is, for example, 10 to 90% by weight, and preferably 40 to 80% by weight. The blending amount of water may be, for example, the balance of other components.

  The water-soluble organic solvent is classified into, for example, a wetting agent that prevents the ink from drying at the tip of the ink jet head and a penetrating agent that adjusts the drying speed on the surface of the recording paper.

  The wetting agent is not limited, and examples thereof include lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol; dimethylformamide, dimethylacetamide, and the like. Amides; ketones such as acetone; keto alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyhydric alcohols such as polyalkylene glycol, alkylene glycol, and glycerin; 2-pyrrolidone; N-methyl-2-pyrrolidone; , 3-dimethyl-2-imidazolidinone and the like. The polyalkylene glycol is not limited, and examples thereof include polyethylene glycol and polypropylene glycol. The alkylene glycol is not limited, and examples thereof include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, thiodiglycol, and hexylene glycol. Among these, polyhydric alcohols such as alkylene glycol and glycerin are preferable. These wetting agents may be used alone or in combination of two or more.

  The blending amount of the wetting agent is not particularly limited. The blending amount of the wetting agent with respect to the total amount of the ink is, for example, 0 to 95% by weight, preferably 10 to 80% by weight, and more preferably 10 to 50% by weight.

  The inkjet recording ink of the present invention contains dipropylene glycol propyl ether (DPP) as the penetrant. As described above, the blending amount of the DPP is 1 to 3% by weight with respect to the total amount of the ink (a condition of 1 ≦ y ≦ 3). The amount of the DPP is preferably 1.2 to 2.7% by weight.

  The penetrant may be composed only of the DPP, or may further contain other penetrants as long as the effects of the present invention are not impaired.

  The penetrant other than the DPP is not limited, for example, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, Triethylene glycol ethyl ether, triethylene glycol propyl ether, triethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether Le, dipropylene glycol butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol propyl ether, tripropylene glycol butyl ether. One type of penetrant other than the DPP may be used, or two or more types may be used.

As described above, the ink of the present invention contains an acetylene glycol surfactant. The acetylene glycol surfactant includes the surfactant represented by the general formula (3). In the general formula (3), the m and n may be the same or different and are numbers satisfying m + n = 1 to 15, preferably m + n = 3 to 11. R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ may be the same or different and each is a linear or branched alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group.

  As the surfactant represented by the general formula (3), for example, a commercially available product may be used. Examples of the commercially available products include Olfin (registered trademark) E1010, Olphine (registered trademark) E1004, Surfynol (registered trademark) 440 and Surfinol (registered trademark) 465 manufactured by Nissin Chemical Industry Co., Ltd .; Examples thereof include acetylenol (registered trademark) E40 and acetylenol (registered trademark) E100 manufactured by KK.

  As described above, the amount of the surfactant represented by the general formula (3) is 0.5 to 2.5% by weight with respect to the total amount of the ink (0.5 ≦ x ≦ 2.5). Condition). The amount of the surfactant represented by the general formula (3) is preferably 0.6 to 2% by weight.

  The ink for inkjet recording of the present invention may contain a surfactant other than the surfactant represented by the general formula (3) as long as the effects of the present invention are not impaired. The surfactant other than the surfactant represented by the general formula (3) is not limited, and examples thereof include an anionic surfactant “EMAL (registered trademark)” series and “LATEMUL (registered trademark)” manufactured by Kao Corporation. ) ”Series,“ VENOL (registered trademark) ”series,“ NEOPELEX (registered trademark) ”series, NS SOAP, KS SOAP, OS SOAP,“ PELEX (registered trademark) ”series, etc .; manufactured by Lion Corporation Agents “LIPOLAN (registered trademark)” series, “LIPON (registered trademark)” series, “SUNNOL (registered trademark)” series, “LIPOTAC (registered trademark)” series, “ENAGICOL (registered trademark)” series, “LIPAL (registered trademark)” Trademark) ”series,“ LOTAT (registered trademark) ”series, etc .; On-surfactant “EMULGEN (registered trademark)” series, “RHEODOL (registered trademark)” series, “EMASOL (registered trademark)” series, “EXCEL (registered trademark)” series, “EMANON (registered trademark)” series, “ "AMIET (registered trademark)" series, "AMINON (registered trademark)" series, etc .; Nonionic surfactant "DOBANOX (registered trademark)" series, "LEOCOL (registered trademark)" series, "LEOX (registered trademark)" manufactured by Lion Corporation Trademark) series, “LAOL (registered trademark)” series, “LEOCON (registered trademark)” series, “LIONOL (registered trademark)” series, “CADENAX (registered trademark)” series, “LIONON (registered trademark)” series, "LEOFAT (registered trademark)" series etc. That. One type of surfactant other than the surfactant represented by the general formula (3) may be used, or two or more types may be used.

  The ink may further contain a conventionally known additive as required. Examples of the additive include a viscosity adjusting agent, a surface tension adjusting agent, and an antifungal agent. The viscosity modifier is not limited, and examples thereof include polyvinyl alcohol, cellulose, and a water-soluble resin.

  The ink is, for example, a colorant, water, a water-soluble organic solvent, and an acetylene glycol surfactant and, if necessary, other additive components uniformly mixed by a conventionally known method, and is insoluble by a filter. Can be prepared by removing.

  As described above, the ink of the present invention is formulated so that the dipropylene glycol propyl ether and the surfactant represented by the general formula (3) satisfy the conditions (C) and (D). In addition to being excellent in jetting stability and printing quality, it is possible to prevent elution of a compound derived from a rubber member or the like in the ink jet recording apparatus into the ink.

  As described above, the ink of the present invention can be used as, for example, a magenta ink. However, the present invention is not limited to this. The ink of the present invention can be made into an ink of a color other than magenta by using a colorant other than the dye.

  The ink cartridge of the present invention is an ink cartridge containing the ink for inkjet recording of the present invention. As the main body of the ink cartridge of the present invention, for example, a conventionally known one can be used.

  Next, the ink jet recording apparatus of the present invention will be described. The ink jet recording apparatus of the present invention includes the ink cartridge of the present invention. Except for this, the configuration of the ink jet recording apparatus of the present invention may be the same as that of a conventionally known ink jet recording apparatus, for example.

  FIG. 1 shows the configuration of an example of the ink jet recording apparatus of the present invention. As shown in the figure, the ink jet recording apparatus 1 includes four ink cartridges 2, an ink jet head 3, a head unit 4, a carriage 5, a drive unit 6, a platen roller 7, and a purge device 8. Including as a member.

  The four ink cartridges 2 contain one color each of four colors of yellow, magenta, cyan, and black. For example, the magenta ink is the ink of the present invention. The ink jet head 3 performs printing on a recording material P such as recording paper. The head unit 4 includes the inkjet head 3. The four ink cartridges 2 and the head unit 4 are mounted on the carriage 5. The drive unit 6 reciprocates the carriage 5 in a linear direction. The platen roller 7 extends in the reciprocating direction of the carriage 5 and is disposed to face the ink jet head 3.

  The drive unit 6 includes a carriage shaft 9, a guide plate 10, two pulleys 11 and 12, and an endless belt 13. The carriage shaft 9 is disposed at the lower end of the carriage 5 and extends in parallel with the platen roller 7. The guide plate 10 is disposed at the upper end of the carriage unit 5 and extends in parallel with the carriage shaft 9. The two pulleys 11 and 12 are disposed between the carriage shaft 9 and the guide plate 10 at both ends of the carriage shaft 9. The endless belt 13 is stretched between the two pulleys 11 and 12.

  In the ink jet recording apparatus 1, when the pulley 11 is rotated forward and backward by driving the carriage motor 101, the carriage 5 joined to the endless belt 13 is moved along with the forward and reverse rotation of the pulley 11. Along the carriage shaft 9 and the guide plate 10, it reciprocates in a linear direction.

  The recording material P is fed from a paper feed cassette (not shown) provided on the side or lower side of the ink jet recording apparatus 1. The recording material P is introduced between the inkjet head 3 and the platen roller 7. Then, predetermined printing is performed on the recording material P by the ink ejected from the inkjet head 3. Thereafter, the recording material P is discharged from the ink jet recording apparatus 1. In FIG. 1, the paper feed mechanism and paper discharge mechanism for the recording material P are not shown.

  The purge device 8 is provided on the side of the platen roller 7 so as to face the inkjet head 3 when the head unit 4 is at a reset position (in this example, the upper portion of the purge device 8). Has been placed. The purge device 8 includes a purge cap 14, a pump 15 and a cam 16, and an ink storage unit 17. The purge cap 14 covers a plurality of nozzles (not shown) of the inkjet head 3 when the head unit 4 is in the reset position. The pump 15 sucks out defective ink containing bubbles and the like accumulated in the ink jet head 3 by driving the cam 16. Thereby, recovery of the inkjet head is achieved. The sucked defective ink is stored in the ink storage unit 17.

  A wiper member 20 is disposed adjacent to the purge device 8 at a position on the platen roller 7 side of the purge device 8. The wiper member 20 is formed in a spatula shape, and wipes the nozzle forming surface of the inkjet head 3 as the carriage 5 moves. In FIG. 1, a cap 18 covers a plurality of nozzles of the inkjet head 3 that is returned to the reset position when printing is completed in order to prevent ink from drying.

  In the ink jet recording apparatus 1 of this example, the four ink cartridges 2 are mounted on one carriage 5. However, the present invention is not limited to this. In the ink jet recording apparatus of the present invention, the four ink cartridges may be mounted on a plurality of carriages. Further, the ink cartridge may not be mounted on the carriage but may be arranged and fixed in the ink jet recording apparatus. In this aspect, for example, the ink cartridge and the head unit mounted on the carriage are connected by a tube or the like, and the ink is supplied from the ink cartridge to the head unit by the tube or the like.

  Next, examples of the present invention will be described together with comparative examples. The present invention is not limited or restricted by the following examples and comparative examples.

[Examples 1-8 and Comparative Examples 1-13]
The ink composition components (Tables 1 and 2 below) were mixed uniformly. Thereafter, the obtained mixture was filtered using a hydrophilic polytetrafluoroethylene (PTFE) type membrane filter (pore diameter 0.2 μm) manufactured by Toyo Roshi Kaisha, Ltd., so that Examples 1 to 8 and Comparative Example 1 were used. ˜13 ink jet recording inks were obtained. In Tables 1 and 2, dyes (1-A) to (1-F) are compounds represented by the chemical formulas (1-A) to (1-F), respectively, and dyes (2- A) to (2-E) are compounds represented by the chemical formulas (2-A) to (2-E), respectively.

  About the ink of each Example and each comparative example, (a) printing quality evaluation (bleeding), (b) jetting stability evaluation, (c) ozone resistance evaluation, (d) light resistance evaluation, (e) rubber precipitation Evaluation, (f) color development evaluation and (g) comprehensive evaluation were performed by the following methods. Samples for (c) ozone resistance evaluation, (d) light resistance evaluation, and (f) color development evaluation were prepared as follows.

That is, first, the ink cartridges were filled with the inks of the examples and the comparative examples. Subsequently, the ink cartridge was mounted on a digital multifunction device DCP-330C equipped with an inkjet printer manufactured by Brother Industries, Ltd. Next, the ink gradation sample was printed on photographic glossy paper BP61GLA manufactured by Brother Industries, Ltd. to obtain a patch having an initial OD value of 1.0. The OD value was measured with a spectrocolorimeter Spectrolino (light source: D ₆₅ ; field of view: 2 °; status A) manufactured by Gretag Macbeth.

(A) Print quality evaluation (bleeding)
Using a digital multifunction printer DCP-330C equipped with an inkjet printer manufactured by Brother Industries, Ltd., on the office paper W manufactured by Fujitsu Cower Co., Ltd. The evaluation sample was printed using the black ink filled in the ink cartridge LC10BK manufactured by Co., Ltd. The Rag at the boundary between the ink of each example and each comparative example and the black ink was measured by a method according to ISO 13660. Here, “Rag” is the ruggedness of the line defined by ISO 13660, and the “rugget line” indicates a state of undulation with respect to an ideal line edge that should be smooth and straight. The obtained Rag was evaluated according to the following evaluation criteria.

Print quality evaluation (bleeding) standard A: Rag of line is less than 30 B: Rag of line is 30 or more and less than 40 C: Rag of line is 40 or more

(B) Evaluation of jetting stability Using a digital multifunction printer DCP-330C equipped with an inkjet printer manufactured by Brother Industries, Ltd., on office paper W manufactured by Fujitsu Cower Co., Ltd., 100 million dots (approximately 30,000 sheets) Continuous printing was performed. The results of the continuous printing were evaluated according to the following criteria. Non-ejection is a state in which the nozzles of the inkjet head are clogged and the ink is not ejected. The ejection bend is a state in which a part of the nozzles of the inkjet head is clogged and the ink is ejected obliquely without being ejected perpendicularly to the recording paper.

Ejection stability evaluation criteria A: During continuous printing, there was no non-ejection and ejection bend, or there was no non-ejection or ejection bend, but the non-ejection or ejection bend was recovered by purging within 5 times. did.
C: During continuous printing, there were many non-ejections and ejection bends, and both the non-ejections and ejection bends were not recovered after 5 purges.

(C) Ozone resistance evaluation Using the ozone weather meter OMS-H manufactured by Suga Test Instruments Co., Ltd., the gradation sample was measured under the conditions of an ozone concentration of 2 ppm, a bath temperature of 24 ° C, and a bath relative humidity of 60%. Left for hours. Subsequently, the OD value of the patch after the standing was measured in the same manner as described above. Next, the OD value reduction rate (%) was obtained by the following formula (I), and the ozone resistance was evaluated according to the following evaluation criteria. Note that the smaller the OD value reduction rate, the less the deterioration of image quality and the better the ozone resistance.

OD value decrease rate (%) = {(XY) / X} × 100 (I)
X: 1.0 (initial OD value)
Y: OD value after standing

Ozone resistance evaluation standard A: OD value reduction rate is less than 20% C: OD value reduction rate is 20% or more

(D) Light resistance evaluation Using the high energy xenon weather meter SC750-WN manufactured by Suga Test Instruments Co., Ltd., the gradation sample was subjected to xenon under the conditions of a bath temperature of 25 ° C., a bath relative humidity of 50%, and an illuminance of 93 klx. Lamp light was irradiated for 200 hours. Subsequently, the OD value of the patch after the irradiation was measured in the same manner as described above. Next, the OD value reduction rate (%) was determined by the following formula (II), and the light resistance was evaluated according to the following evaluation criteria. Note that the smaller the OD value reduction rate, the less the image quality is deteriorated and the better the light resistance.

OD value reduction rate (%) = {(XY) / X} × 100 (II)
X: 1.0 (initial OD value)
Y: OD value after irradiation

Light resistance evaluation standard A: OD value reduction rate is less than 30% C: OD value reduction rate is 30% or more

(E) Rubber precipitation evaluation Under the condition that the contact area per 1 g of ink is 30 mm ² , a rubber piece (ethylene propylene rubber (EPDM); rubber hardness (measured by former JIS K 6301 A type) 40 °) is applied to the ink. It was immersed and stored in an environment at a temperature of 70 ° C. for 1 week. After the storage, the rubber piece was taken out from the ink, and then the ink was filtered with a hydrophilic polytetrafluoroethylene (PTFE) type membrane filter (pore diameter: 0.2 μm; diameter: 15 mm) manufactured by Toyo Roshi Kaisha, Ltd. The time required for filtration was measured. As a control, the ink before storage was filtered under the same conditions as described above, and the time required for filtration was measured. Next, the increase rate of filtration time was calculated | required by following formula (III), and rubber | gum precipitation nature was evaluated in accordance with the following evaluation criteria.

Increase rate of filtration time = Y / X (III)
X: Filtration time before storage Y: Filtration time after storage

Rubber precipitation evaluation criteria A: Increase rate of filtration time is less than 1.3 times B: Increase rate of filtration time is 1.3 times or more and less than 1.6 times C: Increase rate of filtration time is 1.6 More than double

(F) Evaluation of color developability The gradation sample was visually observed, and whether or not the magenta color was sufficiently expressed was evaluated according to the following evaluation criteria.

Color evaluation criteria A: The magenta color can be sufficiently expressed.
B: A magenta color can be expressed.
C: The magenta color cannot be expressed.

(G) Comprehensive evaluation About each ink, comprehensive evaluation was performed according to the following evaluation criteria from the result of said (a)-(f).

Overall evaluation criteria AA: All evaluation results were A.
A: There was B in any of the evaluation results, but there was no C.
C: C was found in any of the evaluation results.

  The composition and evaluation results of the inks of each example are shown in Table 1 below. The composition and evaluation results of the inks of the comparative examples are shown in Table 2 below. Then, the blending amount [x (% by weight)] of the surfactant represented by the general formula (3) with respect to the total amount of ink in Examples 1 to 8 and Comparative Examples 3 to 6 and the blending amount of DPP with respect to the total amount of ink [y ( The relationship with the weight%)] is shown in FIG.

  As shown in Table 1, the inks of Examples 1 to 6 have all the results of printing quality evaluation (bleeding), jetting stability evaluation, ozone resistance evaluation, light resistance evaluation, rubber precipitation evaluation and color development evaluation. ,It was good. The ink of Example 7 in which y <−2x + 3 was slightly inferior to the inks of Examples 1 to 6 in print quality evaluation (bleeding), but it was at a level causing no practical problem. The ink of Example 8 in which y> −2x + 6 was slightly inferior to the inks of Examples 1 to 6 in terms of rubber precipitation evaluation, but it was at a level where there was no practical problem. On the other hand, as shown in Table 2, the ink of Comparative Example 1 not containing the dye (1) was inferior in the results of ozone resistance evaluation and light resistance evaluation. Moreover, the ink of the comparative example 2 which is dye (1): dye (2) [weight ratio] = 6: 4 was inferior in the results of ozone resistance evaluation and light resistance evaluation. Further, the ink of Comparative Example 3 where y <1 was inferior in the print quality evaluation (bleeding) result. Further, the ink of Comparative Example 4 in which y> 3 was inferior in the jetting stability evaluation result. Further, the ink of Comparative Example 5 in which x <0.5 was inferior in the print quality evaluation (bleeding) result. Further, the ink of Comparative Example 6 in which x> 2.5 was inferior in the rubber deposition evaluation result. Further, the ink of Comparative Example 7 containing no DPP was inferior in print quality evaluation (bleeding) due to dipropylene glycol methyl ether blended in place of DPP. In addition, the inks of Comparative Examples 8 and 9 that did not contain DPP had inferior rubber deposition evaluation results due to dipropylene glycol butyl ether or propylene glycol propyl ether blended in place of DPP. Further, in place of the dye (2), C.I. I. Acid Red 14 or C.I. I. The inks of Comparative Example 10 and Comparative Example 11 using Direct Red 227 were inferior in the results of ozone resistance evaluation and light resistance evaluation. Further, the ink of Comparative Example 12 having a small total amount of dyes was printed too thin, and the color development evaluation result was inferior. Further, the ink of Comparative Example 13 having a large total amount of dyes was printed too darkly, and the color development evaluation result was inferior.

  As described above, the ink of the present invention is excellent in color developability, jetting stability, and print quality, prevents elution of a compound derived from a rubber member or the like in an ink jet recording apparatus into the ink, and the recorded matter. It is also excellent in robustness. The use of the ink of the present invention is not limited and can be widely applied to various ink jet recordings.

FIG. 1 is a schematic perspective view showing an example of the configuration of the ink jet recording apparatus of the present invention. FIG. 2 shows the blending amount [x (% by weight)] of the surfactant represented by the general formula (3) with respect to the total amount of ink in Examples 1 to 8 and Comparative Examples 3 to 6, and the blending amount of DPP with respect to the total amount of ink [ It is a figure which shows the relationship with y (weight%)].

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Ink cartridge 3 Inkjet head 4 Head unit 5 Carriage 6 Drive unit 7 Platen roller 8 Purge device 9 Carriage shaft 10 Guide plate

Claims (4)

An ink for ink jet recording comprising a colorant, water, a water-soluble organic solvent, and an acetylene glycol surfactant,
The colorant includes the following dye (1) and dye (2),
The water-soluble organic solvent comprises dipropylene glycol propyl ether;
The acetylene glycol-based surfactant contains a surfactant represented by the following general formula (3),
The surfactant represented by the dye (1), the dye (2), the dipropylene glycol propyl ether, and the general formula (3) satisfy the following conditions (A) to (E), respectively. An ink for ink-jet recording, characterized by being formulated.
Dye (1): Dye dye represented by the following general formula (1) (2): Dye whose free acid is represented by the following general formula (2)
(A) The total amount of the dye (1) and the dye (2) is 2 to 5% by weight based on the total amount of the ink.
(B) The weight ratio of the dye (1) and the dye (2) in the ink is dye (1): dye (2) = 9: 1 to 7: 3
(C) 0.5 ≦ x ≦ 2.5
(D) 1 ≦ y ≦ 3
(E) y ≧ −2x + 3 and y ≦ −2x + 6
x: blending amount (wt%) of the surfactant represented by the general formula (3) with respect to the total amount of the ink
y: blending amount of dipropylene glycol propyl ether with respect to the total amount of ink (% by weight)

In the general formula (1),
R ₁ is a substituted or unsubstituted alkyl group is,
R ₂ is a cyano group,
R ₃ is a substituted or unsubstituted heterocyclic group,
R ₄ , R ₅ , R ₆ and R ₇ are each a hydrogen atom , a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group , and R ₄ , R ₅ , R ₆ and R ₇ are They may be the same or different, but R ₄ and R ₅ are not both hydrogen atoms, R ₆ and R ₇ are not both hydrogen atoms,
A ₁ and A ₂ are carbon atoms having an alkyl group having 1 to 3 carbon atoms, a carboxyl group, a carbamoyl group, or a cyano group, or CH, and both A ₁ and A ₂ are CH. There is no .

In the general formula (2),
R ₈ , R ₉ and R ₁₀ are each a substituted or unsubstituted alkyl group , a hydrogen atom , a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group , or a carboxyl group , and R ₈ , R ₉ and R ₁₀ may be the same or different,
k is 0 ,
R ₁₁ , R ₁₂ and R ₁₃ are each a hydrogen atom, a substituted or unsubstituted alkyl group , or a substituted or unsubstituted aryl group , and R ₁₁ , R ₁₂ and R ₁₃ may be the same or different.

In the general formula (3), m and n may be the same or different, and are numbers satisfying m + n = 1 to 15,
R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ may be the same or different and each is a linear or branched alkyl group having 1 to 5 carbon atoms.   The ink for inkjet recording according to claim 1, which is used as a magenta ink.   An ink cartridge comprising an ink jet recording ink, wherein the ink is the ink jet recording ink according to claim 1.   An ink jet recording apparatus comprising an ink cartridge and ink ejecting means, wherein ink for ink jet recording is ejected from the ink ejecting means, wherein the ink cartridge is the ink cartridge according to claim 3. apparatus.

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