JP3178200B2 - Black ink composition with excellent black reproducibility - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Background of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition having excellent black reproducibility and an ink jet recording method using the same.

[0002]

2. Description of the Related Art Black ink is an important ink composition used for both mono-color and full-color ink compositions for ink jet recording. Examples of black ink dyes include C.I. I. Food black 2 (JP-A-59-93766, etc.) and dyes having a structure similar thereto (JP-A-3-91577, etc.) have been widely used.

[0003] However, these dyes tend to have a slightly bluish hue, which is slightly different from the original black (for example, black such as black ink or lacquer).

[0004] In order to improve the hue, it has been proposed to combine these dyes with other dyes (JP-A-2-36279). However, a decrease in the storage stability of the ink was sometimes observed by combining the dye. Furthermore, when such an ink is used in an ink jet printer having a high density of 300 dpi or more and a high frequency of 5 kHz or more, the ejection stability is poor,
In some cases, nozzle clogging may occur. It has also been proposed to use a special recording material (for example, coated paper having an ink receiving layer containing a pigment and a binder formed on a base material such as paper) in order to improve image quality. When such coated paper is used, the reproducibility of black is excellent, but it can be said that it is desired to be able to reproduce good black even on plain paper and obtain a clear image.

Further, in the case of aqueous inks using water-soluble dyes, improvement of the water resistance of printed matter is mentioned as a general problem (for example, JP-A-3-91577, JP-A-4-226175). And JP-A-4-233975). Even with the ink composition described in JP-A-2-36279, it can be said that there is room for improvement in the water resistance of the printed matter.

[0006] Further, the ink composition used in the ink jet recording system must not clog the discharge nozzles, can be easily recovered even if clogging occurs, and change the physical properties of the ink during storage. Characteristics such as not to do are generally required. Therefore, in the ink composition for ink-jet recording, it is necessary to satisfy requirements such as excellent black reproducibility and water resistance, not to clog the nozzle, and excellent clogging recovery and storage stability. is there.

[Summary of the Invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink composition which can reproduce good black color and has excellent storage stability, and an ink jet recording method using the same.

Another object of the present invention is to provide an ink composition capable of reproducing a good black color on plain paper and forming a clear image, and an ink jet recording method using the same.

Further, the present invention provides an ink composition which satisfies various characteristics required for an ink composition for ink jet recording, such as, for example, preventing clogging of nozzles and excellent storage stability, in addition to water resistance. Its purpose is to provide.

The present inventors have recently obtained an ink composition which can reproduce good black color, and is excellent in clogging recovery and storage stability by combining two kinds of dyes having a specific structure. I found that.

[0011]

That is, the ink composition according to the present invention comprises a first dye represented by the following general formula (I) and a C.I. I. Direct Yellow 86, 132 and 144, and the following general formula (II) and general formula
And a second dye selected from the group consisting of the compounds represented by (III).

[0012]

Embedded image

(Wherein R ¹ is a hydroxyl group, —NH ₂ , —S
O 3 _M or -COOM (wherein, M is a hydrogen atom or, an alkali metal, ammonia or represents a cation species derived from an amine) represents optionally substituted by a phenyl group or a naphthyl group, R ² is A carboxyalkyl group (where the carboxy group may form a salt with an alkali metal or ammonia), an optionally substituted alkoxyalkyl group, an optionally substituted phenyl group or an alkanoyl group; ³ , R ⁴ and R
⁵ may be the same or different, or _-SO 3 M (wherein, M represents the same meaning as defined above) each represents a hydrogen atom represent a proviso, ^{R 1} is in the -SO ₃ M Represents a substituted phenyl group, and R ³ , R ⁴ and R ^{5 do not} represent a case where all of —SO ₃ M is represented)

[0014]

Embedded image

(Wherein R ⁶ is a hydroxyl group, —NH ₂ , —S
O 3 _M or -COOM (wherein, M is a hydrogen atom or, an alkali metal, ammonia or represents a cation species derived from an amine) represents optionally substituted by a phenyl group or a naphthyl group, R ⁷ is Hydrogen atom or -S
O ₃ M (where M represents the same meaning as defined above)

[0016]

Embedded image

(In the formula, R ⁸ and R ⁹ may be the same or different and each represent a hydrogen atom, an alkyl group or a hydroxyalkyl group, but R ⁸ and R ⁹ do not simultaneously represent a hydrogen atom. , R ¹⁰ and R ¹¹ are
May be the same or different, and represent a hydrogen atom, an alkyl group or an alkoxy group, respectively)

[Specific Description of the Invention] First Dye The first dye used in the ink composition according to the present invention is:
A compound represented by the above general formula (I). The compound represented by the general formula (I) is a dye used alone as a dye for a black ink. In the present invention, the ink composition is added in combination with a dye described below to obtain an ink composition.

In formula (I), the phenyl group or naphthyl group represented by R ¹ may be unsubstituted or substituted. When R ¹ represents a substituted phenyl group, a mono-substituted (preferably 3- or 4-substituted) phenyl group,
And di-substitution (preferably at 2,4-position or 3,
Compounds that are (5-substituted disubstituted) phenyl groups are preferred. Preferred substituents include hydroxyl, -NH _2, a sulfonic acid group and a carboxy group. The sulfonic acid group and the carboxy group may be a free acid or may form a salt. Preferred salts include alkali metals, ammonia and amines (preferably tri (hydroxy C
_1-6 alkyl) amine).

The naphthyl group represented by R ¹ may be either 1- or 2-naphthyl, and may be unsubstituted or substituted. When R ¹ is a substituted naphthyl, preferred substituents are the same as those described for the phenyl group.

In the general formula (I), the carboxyalkyl group represented by R ² is preferably carboxy C _1-6
An alkyl group, more preferably a carboxy C _1-4 alkyl group. This carboxy group preferably forms a salt with an alkali metal or ammonia. Also, R ²
The alkoxyalkyl group represented by is preferably a C _1-6 alkoxy C _1-6 alkyl group, more preferably C _1-4
It is an alkoxy C _1-4 alkyl group. One or more hydrogen atoms present in the alkoxyalkyl group may be substituted, and preferred examples of the substituent include a hydroxyl group, -NH
_{2 and the} like. Further, the phenyl group represented by R ² may be substituted, and preferred examples of the substituent include a hydroxyl group and —NH ₂ . Still further, the alkanoyl group represented by R ² is preferably a C _1-6 alkanoyl group, more preferably a C _1-4 alkanoyl group. In formula (I), R ³ , R ⁴ and R ⁵ may be the same or different and each represent a hydrogen atom or a sulfonic acid group. This sulfonic acid group may be a free acid or may form a salt. Preferred salts include salts with alkali metals, ammonia, and amines (preferably, tri (hydroxyC _1-6 alkyl) amine).

In the general formula (I), R ¹ is —SO ₃ M
Wherein R ³ , R ⁴ and R ⁵ all represent —SO ₃ M, cannot be used in the ink composition of the present invention. This is because, according to the experiments of the present inventors, the ink composition using such a compound group did not show preferable various properties.

Preferred specific examples of the compound represented by the formula (I) are as shown in the following table.

[0024]

Embedded image

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

The dye of the general formula (I) can be produced by a known method or a method similar thereto. For example, the dye of the general formula (I) is disclosed in JP-A-2-1402.
No. 70, Color Index Third Edition (Colour Index,
Third Edition, The society of Dyers and Colorists)
Can be produced.

Second Dye The second dye used in the ink composition according to the present invention is:
C. I. Direct Yellow 86, 132 and 14
4, and the following general formulas (II) and (III)
A dye selected from the group consisting of the compounds represented by C. I. Direct Yellow 86, 132 and 1
44 is, for example, the third edition of Color Index (Colour Inde
x, Third Edition, The society of Dyers and Colorist
s).

The compound represented by the general formula (II) is a compound used alone as a dye. In the general formula (II), the phenyl group or naphthyl group represented by R ⁶ may be unsubstituted or substituted. When R ⁶ represents a substituted phenyl group, preferred examples of the substituent include a hydroxyl group, —NH ₂ , a sulfonic acid group, and a carboxy group. The sulfonic acid group and the carboxy group may be a free acid or may form a salt. Preferred salts include salts with alkali metals, ammonia, and amines (preferably, tri (hydroxyC _1-6 alkyl) amine). The position of these substituents is not particularly limited, but is preferably in the 3- or 4-position. Further, the naphthyl group represented by R ⁶ may be 1- or 2-naphthyl, and may be unsubstituted or substituted. When R ¹ is a substituted naphthyl, preferred substituents are the same as those described for the phenyl group.

Preferred specific examples of the compound represented by the general formula (II) are as shown in the following table.

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

The dye of the general formula (II) can be produced by a known method or a method similar thereto. For example, the dye of the general formula (II) is disclosed in JP-A-2-1402.
No. 70 is described as an intermediate of black paint,
It can be manufactured according to the description in this publication.

The compound represented by the general formula (III) is a compound used alone as a dye similarly to the compound of the general formula (II). In the general formula (III), R ⁸ and R
^The alkyl group represented by ⁹ preferably represents a C _1-6 alkyl group, more preferably a C _1-4 alkyl group. Also,
The hydroxyalkyl group represented by R ⁸ and R ⁹ preferably represents a hydroxy C _1-6 alkyl group, more preferably a hydroxy C _1-4 alkyl group. Compounds in which R ⁸ and R ⁹ simultaneously represent a hydrogen atom are excluded from the scope of the present invention. The alkyl group represented by R ¹⁰ and R ¹¹ in the general formula (III) preferably represents a C _1-6 alkyl group, more preferably a C _1-4 alkyl group. Further, the alkoxy group represented by R ¹⁰ and R ¹¹ preferably represents a C _1-6 alkoxy group, more preferably a C _1-4 alkoxy group.

Preferred specific examples of the compound represented by the general formula (III) are as shown in the following table.

[0038]

Embedded image

The dye of the general formula (III) can be produced by a known method or a method similar thereto. For example, the dye of the general formula (III) is disclosed in JP-A-3-1791.
No. 00, Color Index, 3rd edition (Colour Index,
Third Edition, The society of Dyers and Colorists)
Can be produced.

Ink Composition The ink composition according to the present invention preferably contains the dye of the formula (I) in the range of 0.1 to 10% by weight, more preferably 1 to 5% by weight. . General formula (I)
If the dye is less than the above range, printing of sufficient density may not be obtained, and if it exceeds the range, the dissolution stability of the dye may be deteriorated and nozzle clogging may occur. The dyes of the general formula (I) may be used alone or in admixture of two or more.

According to the present invention, an ink composition having excellent black reproducibility is provided by containing the second dye together with the first dye.

The ink composition according to the present invention contains C.I. I. Direct Yellow 86, 132 or 144 is preferably contained in the range of 0.001 to 0.5% by weight, more preferably 0.005 to 0.4% by weight.

When the second dye is a dye of the general formula (II), the ink composition according to the present invention comprises
Is preferably contained in the range of 0.001 to 0.5% by weight, more preferably 0.05 to 0.4% by weight.
It is.

When the second dye is a dye represented by the general formula (III), the ink composition according to the present invention comprises a compound represented by the general formula (III):
Is preferably contained in the range of 0.005 to 0.5% by weight, more preferably 0.01 to 0.4% by weight.
It is.

These second dyes may be used alone or in admixture of two or more. As the solvent of the ink composition according to the present invention, water or a mixed solvent of water and a water-soluble organic solvent can be used, and a mixed solvent of water and a water-soluble organic solvent is preferable. Examples of the water-soluble organic solvent used by mixing with water include lower alcohols such as ethanol, 1-propanol and 2-propanol; ethylene glycol, diethylene glycol, triethylene glycol,
Polyhydric alcohols such as propylene glycol and glycerin; ethers of polyhydric alcohols such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether propene glycol monoethyl ether; formamide, dimethylformamide, diethanolamine, triethanolamine, 1,3-dimethyl −
2-imidazolidinone, 2-pyrrolidone, N-methyl-
Nitrogen-containing compounds such as 2-pyrrolidone; and sulfur-containing compounds such as thiodiglycol and dimethylsulfoxide. In particular, the addition of a nitrogen-containing compound such as 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidone, N-methyl-2-pyrrolidone is preferred from the viewpoint of clogging recovery, and the preferred addition amount is 1 to 10% by weight. %.
Furthermore, the addition of triethanolamine makes the dye develop color,
It is preferable from the viewpoint of print density, and a preferable addition amount is 0.5.
About 2% by weight.

Further, a dye may be further added to the ink composition according to the present invention as long as the effect such as black reproducibility is not impaired. According to a preferred embodiment of the present invention, the addition of a dye having surface-active properties is advantageous. By the addition of a dye having such a surface activity,
The wettability of the ink composition to the recording head and the ink flow path is improved. As a result, air bubbles that have entered the recording head or the ink flow path are easily discharged.
Specific examples of such dyes include C.I. I. Direct Black 154, 168 and the like.

Further, the ink composition according to the present invention may contain various additives as necessary to improve various properties of the ink composition. Examples of the additives include resins, polymers, surfactants, pH adjusters, and mildew-proofing agents. Agents, ultraviolet absorbers and the like can be added.

[0048]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Production of Ink Compositions Ink compositions having the compositions shown in the following Tables 1 to 5, ie, Examples A1 to 10, B1 to 10, C1 to 12, and D1
-10 and E1-11 and Comparative Examples A1-3, B1
-3, C1-3, D1-3 and E1-3 were produced as follows. That is, the components were sufficiently mixed, and the mixture was pressure-filtered with a membrane filter having a pore size of 0.8 μm. Thereafter, a vacuum pump deaeration treatment was performed to obtain an ink composition. The remaining amount of the components in the table is water.

Evaluation Test Various properties of the ink compositions according to the above Examples and Comparative Examples were evaluated as follows. The results are as shown in the table. In the evaluation test, a print sample and a solid print sample were prepared using the ink compositions of the above Examples and Comparative Examples using an inkjet printer HG-51.
30 (manufactured by Seiko Epson Corporation). Furthermore, the evaluation in parentheses in the table is the result of an evaluation test similarly performed using an inkjet printer BJ-330 (manufactured by Canon Inc.). Further, the recording papers (a) to (e) in the evaluation tests (2) and (6) are (a) coated paper for inkjet NM (from Mitsubishi Paper Mills Co., Ltd.) and (b) Cannon D, respectively.
ry (from Canon Sales Co., Ltd.), (c) Xerox 4024
(Xerox Co.), (d) Xerox P (from Fuji Xerox Co., Ltd.) and (e) Ricopy 6200 (from Ricoh Co., Ltd.).

Evaluation Test 1: Water Resistance (1) A water drop was dropped on a printed portion of a printed sample, and the state of the sample after air drying was observed. The sample was evaluated as follows. ：: No change from initial state, ○: Dye is slightly dissolved, but characters are clearly readable, Δ: Bleed but characters are readable, ×: Character is bleed and not readable. (2) The solid print sample was immersed in water for 24 hours. From the OD value before immersion and the OD value after immersion, according to the following formula,
The water resistance was evaluated.

Evaluation Test 2: Jet Blackness The color tone of the solid print sample printed on the recording papers (a) to (e) was visually observed and evaluated as follows. ◎: almost pure black and clear, ：: pure black but slightly lacking in sharpness, Δ: pure black but poor in definition, ×: close to black but a hue different from black is observed.

Evaluation test 3: Clogging recovery property An ink jet printer HG-5130 was filled with the ink composition, and the recording head was heated at 40 ° C. without capping.
Left for months. Thereafter, the number of cleaning operations until normal printing became possible was evaluated as follows. ◎: 0 to 2 times ○: 3 to 5 times △: 5 times or more ×: No recovery

Evaluation Test 4: Discharge Stability (1) Using a piezo-drive type on-demand type ink jet recording head (48 nozzles, 40 μm diameter)
Continuous printing was performed on 1,000 sheets of recording paper at a driving frequency of 7.2 and 10 kHz. The results were evaluated as follows. ：: No abnormality ×: Discharge failure or printing disorder occurred (2) The number of cleaning operations until printing could be performed without missing dots after intentionally introducing air bubbles into the head of the inkjet printer was evaluated as follows. . ◎: 1 time ○: 2 to 3 times △: 4 to 5 times ×: 5 times or more or no recovery

Evaluation Test 5: Storage Stability The ink composition was sealed in a glass container,
Left at 0 ° C. for one month. Before and after the standing, it was observed whether there was no change in the physical properties and color tone of the ink, and after the standing, whether there was any precipitation of insoluble matter, and evaluated as follows. ：: No change in physical properties and color tone, no generation of precipitates Δ: Change in physical properties and color tone X: Change in physical properties or color tone, or generation of precipitates

Evaluation Test 6: Image Quality The print was visually observed, and the sharpness of the image was evaluated from the viewpoint of blurring and density as follows. ◎: No bleeding, high density. ：: Slight bleeding is observed, but there is no effect on the image and the density is high. ×: Severe bleeding, low density.

Evaluation Test 7: Light Resistance A solid printed sample was irradiated with light for 50 hours using a xenon fade meter, and the change rate of the OD value before and after irradiation was evaluated as follows. ：: 0 to less than 5% Δ: 5 to less than 10% ×: 10 or more

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

[0061]

[Table 4]

[0062]

[Table 5]

[0063]

[Table 6]

[0064]

[Table 7]

[0065]

[Table 8]

[0066]

[Table 9]

[0067]

[Table 10]

Continued on the front page (31) Priority claim number Japanese Patent Application No. 5-35725 (32) Priority date February 24, 1993 (1993.2.24) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 5-105579 (32) Priority date May 6, 1993 (1993.5.6) (33) Priority claim country Japan (JP) (56) References 132169 (JP, A) JP-A-60-108470 (JP, A) JP-A-4-233975 (JP, A) JP-A-5-2955311 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (6)

(57) [Claims] (1) a first dye represented by the following general formula (I): I. Direct Yellow 86, 132 and 1
44, and the following general formula (II) and general formula (II
An ink composition comprising a second dye selected from the group consisting of the compounds represented by I). Embedded image (Wherein, R ¹ is a hydroxyl group, —NH ₂ , —SO ₃ M, or —COO
M (where M represents a hydrogen atom or a cationic species derived from an alkali metal, ammonia or an organic amine)
Represents a phenyl group or a naphthyl group which may be substituted; R ² represents a hydrogen atom, a carboxyalkyl group (where the carboxy group may form a salt with an alkali metal or ammonia), Represents an optionally substituted alkoxyalkyl group, an optionally substituted phenyl group or an alkanoyl group, wherein R ³ , R ⁴ and R ⁵ may be the same or different and each represents a hydrogen atom or —SO ₃ M (here, , M represents the same meaning as defined above), provided that R ¹ represents a phenyl group substituted with -SO ₃ M, and all of R ³ , R ⁴ and R ⁵ represent -SO ₃
Except when it represents M) (Wherein, R ⁶ represents a hydroxyl group, —NH ₂ , —SO ₃ M, or —COO
M (where M represents a hydrogen atom or a cationic species derived from an alkali metal, ammonia or an organic amine)
Represents a phenyl group or a naphthyl group which may be substituted, and R ⁷ represents a hydrogen atom or —SO ₃ M (where M has the same meaning as defined above). (Wherein R ⁸ and R ⁹ may be the same or different,
Each represents a hydrogen atom, an alkyl group or a hydroxyalkyl group, but R ⁸ and R ⁹ do not represent a hydrogen atom at the same time, and R ¹⁰ and R ¹¹ may be the same or different; Or represents an alkoxy group) 2. R ¹ is a hydroxyl group, —NH ₂ , —SO ₃ M or —COOM (where M is a hydrogen atom, or an alkali metal, ammonia or tri (hydroxy C
_1-6 alkyl) represents a cation species derived from an amine) represents optionally substituted phenyl or naphthyl group, R ² is a hydrogen atom, a carboxyalkyl group (wherein the carboxy group is an alkali metal or ammonia salts may also be in the form), represent optionally substituted _{C 1-6} alkoxy _{C 1-6} alkyl group, an optionally substituted phenyl group or a _{C 1-6} alkanoyl group, ^R 3, R ⁴ and R ⁵ are identical or different, _(wherein, M represents the same meaning as defined above) each represents a hydrogen atom or -SO 3 M comprising a dye of the general formula (I) representing the The ink composition according to claim 1. 3. A dye of the formula (I) in an amount of 0.1 to 10% by weight.
The ink composition according to claim 1, which is contained. 4. The method according to claim 1, I. Direct Yellow 86, 132
The ink composition according to claim 1, wherein the ink composition comprises 0.001 to 0.5% by weight of 144. 5. The dye of the formula (II) is used in an amount of from 0.001 to 0.
2. The ink composition according to claim 1, comprising 5% by weight. 6. A dye of the formula (III) in an amount of 0.005 to 0.5.
2. The ink composition according to claim 1, comprising 5% by weight.