JP2011111606A - Water-based ink for ink-jet recording, ink cartridge, and ink-jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based ink for ink-jet recording, excellent in light resistance and ozone resistance and excellent in colorability and bronzing. <P>SOLUTION: The water-based ink for the ink-jet recording, comprising a coloring agent, water and a water-soluble organic solvent, is characterized in that the coloring agent comprises the following dyes (1) and (2). The water-soluble ink is excellent in all the performances of colorability, bronzing, ozone resistance and light resistance. The dye (1) is a copper phthalocyanine dye having a SO<SB>3</SB>Na group, a SO<SB>2</SB>NH<SB>2</SB>group and a triazine ring-having substituted sulfonamide group; the dye (2) is C.I. Direct Blue 86. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an aqueous inkjet recording ink, an ink cartridge, and an inkjet recording apparatus.

  Conventionally, as cyan ink for ink jet recording, C.I. I. Acid Blue 74 and C.I. I. An ink containing a cyan dye such as Acid Blue 9 is known. However, the cyan dye has insufficient light resistance. For this reason, commercially available cyan ink for inkjet recording includes C.I. I. Direct Blue 86 and C.I. I. Copper phthalocyanine dyes such as Direct Blue 199 are widely used. Although these general copper phthalocyanine dyes are excellent in light resistance compared to magenta dyes and yellow dyes, they are easily discolored and discolored by contact with ozone, causing color changes and a decrease in optical density in the recorded matter. There is a problem. For this reason, a copper phthalocyanine dye having improved ozone resistance has been proposed (Patent Document 1).

  In addition to being excellent in light resistance and ozone resistance, the cyan ink is required to have excellent color developability and bronzing. However, none of the conventional cyan inks satisfy all the above performances. The bronzing is a phenomenon in which glare (irregular reflection) like metallic luster occurs on the surface of a recording medium such as glossy paper due to association or aggregation of dyes.

Japanese Patent Laid-Open No. 3-103484

  Accordingly, an object of the present invention is to provide a water-based ink for ink jet recording which is excellent in light resistance and ozone resistance, and is excellent in color development and bronzing.

一般式（１）において、
環Ａ_１、Ａ_２およびＡ_３は、それぞれ、ベンゼン環、２，３−ピリジン環および３，２−ピリジン環からなる群から選択される少なくとも一つであり、且つ、環Ａ_１、Ａ_２およびＡ_３の少なくとも一つは、２，３−ピリジン環または３，２−ピリジン環であり、環Ａ_１、Ａ_２およびＡ_３は同一でも異なっていてもよく、
ｌは、０≦ｌ≦４を満たし、ｍは、０≦ｍ≦４を満たし、ｎは、０≦ｎ≦４を満たし、且つ、ｌ、ｍおよびｎは、０≦ｌ＋ｍ＋ｎ≦４を満たし、
ｚは、１≦ｚ≦３を満たす整数であり、
Ｒ_１は、炭素原子数１〜６の直鎖アルキル基である。 In order to achieve the above object, the water-based ink for ink-jet recording of the present invention is a water-based ink for ink-jet recording containing a colorant, water and a water-soluble organic solvent,
The colorant contains the following dye (1) and dye (2).
Dye (1): Dye represented by general formula (1) (2): C.I. I. Direct Blue 86

In general formula (1),
Each of the rings A ₁ , A ₂ and A ₃ is at least one selected from the group consisting of a benzene ring, a 2,3-pyridine ring and a 3,2-pyridine ring, and the rings A ₁ , A ₂ And at least one of A ₃ is a 2,3-pyridine ring or a 3,2-pyridine ring, and the rings A ₁ , A ₂ and A ₃ may be the same or different;
l satisfies 0 ≦ l ≦ 4, m satisfies 0 ≦ m ≦ 4, n satisfies 0 ≦ n ≦ 4, and l, m, and n satisfy 0 ≦ l + m + n ≦ 4,
z is an integer satisfying 1 ≦ z ≦ 3,
R ₁ is a linear alkyl group having 1 to 6 carbon atoms.

  In order to achieve the above object, the present inventors have made a series of researches. As a result, if the dye (1) and the dye (2) are used in combination in a water-based ink for ink jet recording, color developability and bronzing. The present inventors have found out that all the performances of ozone resistance and light resistance are excellent, and have reached the present invention.

FIG. 1 is a schematic perspective view showing an example of the configuration of the ink jet recording apparatus of the present invention.

  The water-based ink for ink-jet recording of the present invention (hereinafter sometimes simply referred to as “water-based ink” or “ink”) will be described. The water-based ink of the present invention contains a colorant, water, and a water-soluble organic solvent. 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),
Each of the rings A ₁ , A ₂ and A ₃ is at least one selected from the group consisting of a benzene ring, a 2,3-pyridine ring and a 3,2-pyridine ring, and the rings A ₁ , A ₂ And at least one of A ₃ is a 2,3-pyridine ring or a 3,2-pyridine ring, and the rings A ₁ , A ₂ and A ₃ may be the same or different;
l satisfies 0 ≦ l ≦ 4, m satisfies 0 ≦ m ≦ 4, n satisfies 0 ≦ n ≦ 4, and l, m, and n satisfy 0 ≦ l + m + n ≦ 4,
z is an integer satisfying 1 ≦ z ≦ 3,
R ₁ is a linear alkyl group having 1 to 6 carbon atoms.
The compound represented by the general formula (1) may be a compound in which all of rings A ₁ , A ₂ and A ₃ are 2,3-pyridine rings or 3,2-pyridine rings, or ring A ₁ , A compound in which two of A ₂ and A ₃ are 2,3-pyridine rings or 3,2-pyridine rings and the remaining one is a benzene ring may be used, or rings A ₁ , A ₂ and A ₃ One of them may be a 2,3-pyridine ring or 3,2-pyridine ring, and the other two may be a benzene ring.
The dye (1) may be composed of a single compound or a mixture containing two or more compounds.

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

化学式（１−Ａ）において、
環Ａ_１、Ａ_２およびＡ_３は、それぞれ独立に、２，３−ピリジン環および／または３，２−ピリジン環であり、
ｌは、１．０であり、ｍは、１．８であり、ｎは、１．２であり、ｌ、ｍおよびｎは、混合物における平均値である。

In the chemical formula (1-A),
Rings A ₁ , A ₂ and A ₃ are each independently a 2,3-pyridine ring and / or a 3,2-pyridine ring;
l is 1.0, m is 1.8, n is 1.2, and l, m, and n are average values in the mixture.

化学式（１−Ｂ）において、
環Ａ_１およびＡ_２は、それぞれ独立に、２，３−ピリジン環および／または３，２−ピリジン環であり、環Ａ_３は、ベンゼン環であり、
ｌは、２．４であり、ｍは、０．６であり、ｎは、１．０であり、ｌ、ｍおよびｎは、混合物における平均値である。

In the chemical formula (1-B),
Rings A ₁ and A ₂ are each independently a 2,3-pyridine ring and / or a 3,2-pyridine ring, Ring A ₃ is a benzene ring,
l is 2.4, m is 0.6, n is 1.0, and l, m and n are average values in the mixture.

化学式（１−Ｃ）において、
環Ａ_１、Ａ_２およびＡ_３は、それぞれ独立に、２，３−ピリジン環および／または３，２−ピリジン環であり、
ｌは、３．０であり、ｍは、０．２であり、ｎは、０．８であり、ｌ、ｍおよびｎは、混合物における平均値である。

In the chemical formula (1-C),
Rings A ₁ , A ₂ and A ₃ are each independently a 2,3-pyridine ring and / or a 3,2-pyridine ring;
l is 3.0, m is 0.2, n is 0.8, l, m and n are average values in the mixture.

化学式（１−Ｄ）において、
環Ａ_１は、ベンゼン環であり、環Ａ_２およびＡ_３は、それぞれ独立に、２，３−ピリジン環および／または３，２−ピリジン環であり、
ｌは、１．８であり、ｍは、０．９であり、ｎは、１．３であり、ｌ、ｍおよびｎは、混合物における平均値である。

In chemical formula (1-D),
Ring A ₁ is a benzene ring, Rings A ₂ and A ₃ are each independently a 2,3-pyridine ring and / or a 3,2-pyridine ring,
l is 1.8, m is 0.9, n is 1.3, and l, m and n are average values in the mixture.

化学式（１−Ｅ）において、
環Ａ_１、Ａ_２およびＡ_３は、それぞれ独立に、２，３−ピリジン環および／または３，２−ピリジン環であり、
ｌは、１．１であり、ｍは、１．３であり、ｎは、１．６であり、ｌ、ｍおよびｎは、混合物における平均値である。

In chemical formula (1-E),
Rings A ₁ , A ₂ and A ₃ are each independently a 2,3-pyridine ring and / or a 3,2-pyridine ring;
l is 1.1, m is 1.3, n is 1.6, and l, m, and n are average values in the mixture.

化学式（１−Ｆ）において、
環Ａ_１およびＡ_３は、それぞれ独立に、２，３−ピリジン環および／または３，２−ピリジン環であり、環Ａ_２は、ベンゼン環であり、
ｌは、０であり、ｍは、１．８であり、ｎは、２．２であり、ｌ、ｍおよびｎは、混合物における平均値である。

In the chemical formula (1-F),
Rings A ₁ and A ₃ are each independently a 2,3-pyridine ring and / or a 3,2-pyridine ring, Ring A ₂ is a benzene ring,
l is 0, m is 1.8, n is 2.2, and l, m, and n are average values in the mixture.

  The dye (1) can be produced by a conventionally known method. The method for producing the dye (1) is, for example, as follows.

That is, first, a copper porphyrazine compound represented by the structural formula (11) is synthesized. The copper porphyrazine compound represented by the structural formula (11) is, for example, a nitrogen-containing heteroaromatic ring (at least one of a 2,3-pyridine ring and a 3,2-pyridine ring) dicarboxylic acid in the presence of a catalyst and a copper compound. It is obtained by reacting a derivative with a phthalic acid derivative. Adjusting the number of nitrogen-containing heteroaromatic rings and the number of benzene rings of A ₁ , A ₂ and A ₃ by changing the molar ratio of the reaction of the nitrogen-containing heteroaromatic dicarboxylic acid derivative and the phthalic acid derivative. Is possible. The nitrogen-containing heteroaromatic dicarboxylic acid is a carboxyl group at two adjacent positions or a reactive group derived therefrom (for example, an acid amide group, an imide group, an acid anhydride group, a carbonitrile group, etc.). 6-membered nitrogen-containing heteroaromatic dicarboxylic acid derivatives having Examples of the method for synthesizing the copper porphyrazine compound include conventionally known methods such as a nitrile method and a Weiler method.

  Next, the copper porphyrazine compound represented by the structural formula (11) is chlorosulfonated in chlorosulfonic acid, or sulfonated in sulfuric acid or fuming sulfuric acid, and then converted into a chlorosulfo group with a chlorinating agent. A copper chlorosulfonylporphyrazine compound represented by the structural formula (12) is obtained by conversion or the like.

Next, the obtained copper chlorosulfonylporphyrazine compound, the organic amine represented by the structural formula (13) and the aminating agent (ammonia or ammonia-generating compound) are about pH 8 to 10 and 5 in an aqueous solvent. The said dye (1) can be obtained by making it react at 1 degreeC-70 degreeC for 1 hour-20 hours. As the aminating agent, ammonia or a compound that generates ammonia upon the reaction (ammonia generating compound) can be used, and examples thereof include ammonium salts such as ammonium chloride and ammonium sulfate, urea, aqueous ammonia, and ammonia gas. In the organic amine represented by Structural Formula (13), X and Y are each a hydrogen atom or sodium. X and Y may be ionized in the aqueous solvent to form ions (H ⁺ or Na ⁺ ). The organic amine can be produced by a conventionally known method.

  The dye (1) thus obtained can be separated by filtration or the like after aciding out or salting out. For example, salting out is preferably carried out at an acidic to alkaline, preferably pH 1-11. Although the temperature in salting out is not specifically limited, For example, it is 40 to 80 degreeC, Preferably, it is 50 to 70 degreeC.

  The dye (1) synthesized by the above method is obtained in the form of a free acid or a salt thereof. In order to obtain a free acid, for example, acid precipitation may be performed. In order to form a salt, for example, a normal salt exchange method of salting out or adding a desired organic or inorganic base to a free acid may be used.

  The blending amount of the dye (1) is not particularly limited. By including the dye (1) in the water-based ink, ozone resistance and light resistance can be improved. The blending amount of the dye (1) is, for example, 0.1% by weight to 10% by weight, preferably 1.4% by weight to 5.7% by weight, and more preferably based on the total amount of the water-based ink. Is 1.6 wt% to 4.8 wt%.

  C. of the dye (2) I. The direct blue 86 is a dye represented by the structural formula (2), for example.

構造式（２）において、
Ｐｃ（Ｃｕ）は、一般式（Ｐｃ）で表される銅フタロシアニン核であり、
ＳＯ_３Ｎａ基は、一般式（Ｐｃ）で表される銅フタロシアニン核中の４つのベンゼン環Ａ、Ｂ、ＣおよびＤのいずれかに存在する。

In structural formula (2):
Pc (Cu) is a copper phthalocyanine nucleus represented by the general formula (Pc),
The SO ₃ Na group is present in any of the four benzene rings A, B, C, and D in the copper phthalocyanine nucleus represented by the general formula (Pc).

  The blending amount of the dye (2) is not particularly limited. Inclusion of the dye (2) in the water-based ink makes it possible to improve color developability and reduce bronzing. The blending amount of the dye (2) is, for example, 0.05% by weight to 5% by weight, preferably 0.1% by weight to 1.8% by weight, and more preferably based on the total amount of the water-based ink. Is 0.25 wt% to 1.5 wt%.

  The weight ratio of the dye (1) to the dye (2) in the water-based ink is preferably dye (1): dye (2) = 70: 30 to 95: 5. By setting the weight ratio within the above range, it is possible to obtain a water-based ink that has extremely good bronzing and ozone resistance in addition to color developability and light resistance.

  The total blending amount of the dye (1) and the dye (2) is not particularly limited, but is preferably 2% by weight to 6% by weight with respect to the total amount of the water-based ink. By setting the total blending amount within the above range, it is possible to obtain a water-based ink that has extremely good color development, bronzing, ozone resistance, light resistance, and jetting stability.

  In addition to the dye (1) and the dye (2), the colorant may further contain other dyes and pigments.

  The water is preferably ion exchange water or pure water. The blending amount (water ratio) of the water with respect to the total amount of the water-based ink is, for example, 10% by weight to 90% by weight, and preferably 40% by weight to 80% by weight. The said water ratio is good also as the remainder of another component, for example.

  Examples of the water-soluble organic solvent include a wetting agent that prevents drying of the water-based ink at the nozzle tip of the ink jet head and a penetrating agent that adjusts the drying speed on the recording medium.

  The wetting agent is not particularly 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 Amides such as acetone; 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; 1,3-dimethyl-2-imidazolidinone and the like. Examples of the polyalkylene glycol include polyethylene glycol and polypropylene glycol. Examples of the alkylene glycol include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, thiodiglycol, and hexylene glycol. These wetting agents may be used alone or in combination of two or more. Among these, polyhydric alcohols such as alkylene glycol and glycerin are preferable.

  The blending amount (humectant ratio) of the wetting agent with respect to the total amount of the water-based ink is, for example, 0% by weight to 95% by weight, preferably 5% by weight to 80% by weight, and more preferably 5% by weight. ~ 50% by weight.

  Examples of the penetrant include glycol ether. Examples of the glycol ether include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol-n-propyl ether, diethylene glycol-n-butyl ether, diethylene glycol-n- Hexyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol-n-propyl ether, triethylene glycol-n-butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol-n-propyl ether, Propylene glycol-n-butyl ether , Dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol-n-propyl ether And tripropylene glycol-n-butyl ether. The said penetrant may be used individually by 1 type, and may use 2 or more types together.

  The blending amount (permeating agent ratio) of the penetrant with respect to the total amount of the water-based ink is, for example, 0 wt% to 20 wt%. By setting the penetrant ratio within the above range, the penetrability of the water-based ink into the recording medium can be made more suitable. The penetrant ratio is preferably 0.1% by weight to 15% by weight, and more preferably 0.5% by weight to 10% by weight.

  The water-based ink may further contain a conventionally known additive as required. Examples of the additive include a surfactant, a pH adjuster, a viscosity adjuster, a surface tension adjuster, and an antifungal agent. Examples of the viscosity modifier include polyvinyl alcohol, cellulose, and a water-soluble resin.

  The water-based ink is obtained by, for example, uniformly mixing a colorant, water, a water-soluble organic solvent, and, if necessary, other additive components by a conventionally known method, and removing insoluble matters with a filter or the like. Can be prepared.

  The water-based ink of the present invention can be used as a water-based cyan ink, for example. However, the present invention is not limited to this. The water-based ink of the present invention can be a water-based ink having a color other than cyan by using a colorant other than the dye (1) and the dye (2).

  Next, the ink cartridge of the present invention will be described. The ink cartridge of the present invention is an ink cartridge containing a water-based ink for ink-jet recording, and the water-based ink is the water-based ink for ink-jet recording of the present invention. As the main body of the ink cartridge, 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 is an ink jet recording apparatus that includes an ink storage portion and an ink discharge means, and discharges the ink stored in the ink storage portion by the ink discharge means. The ink cartridge is accommodated. 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, this ink jet recording apparatus 1 includes four ink cartridges 2, an ink discharge means (ink jet head) 3, a head unit 4, a carriage 5, a drive unit 6, a platen roller 7, and a purge device 8. Are included as main components.

  The four ink cartridges 2 contain one color each of four colors of water-based inks of yellow, magenta, cyan, and black. For example, an ink cartridge containing the water-based cyan ink is the ink cartridge of the present invention. The ink jet head 3 performs recording on a recording medium 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. For example, a conventionally known drive unit 6 can be used as the drive unit 6 (see, for example, Japanese Patent Application Laid-Open No. 2008-246821). The platen roller 7 extends in the reciprocating direction of the carriage 5 and is disposed to face the ink jet head 3. The recording includes printing, printing, printing, and the like.

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

  The purge device 8 sucks out defective ink containing bubbles and the like accumulated in the ink jet head 3. As the purge device 8, for example, a conventionally known device can be used (see, for example, Japanese Patent Application Laid-Open No. 2008-246821).

  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 are returned to the reset position when recording is completed in order to prevent ink from drying.

  In the ink jet recording apparatus, 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.

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 to 14 and Comparative Examples 1 to 6]
The ink composition components (Table 1) were mixed uniformly. Thereafter, the obtained mixture was filtered using a hydrophilic polytetrafluoroethylene (PTFE) type membrane filter (pore diameter 0.20 μm) manufactured by Toyo Roshi Kaisha, Ltd., so that Examples 1 to 14 and Comparative Example 1 were used. -6 water-based inks for inkjet recording were obtained. In Table 1, dyes (1-A) to (1-F) are compounds represented by chemical formulas (1-A) to (1-F), respectively.

  For the water-based inks of Examples and Comparative Examples, (a) color development evaluation, (b) bronzing evaluation, (c) ozone resistance evaluation, (d) light resistance evaluation, (e) jetting stability evaluation, and (f) synthesis. Evaluation was performed by the following method. Samples used for (a) color development evaluation, (b) bronzing evaluation, (c) ozone resistance evaluation and (d) light resistance evaluation were prepared as follows.

  That is, first, the ink cartridges were filled with the water-based inks of Examples and Comparative Examples. Next, the ink cartridge was mounted on a digital multifunction device DCP-385C equipped with an inkjet printer manufactured by Brother Industries, Ltd. Next, the gradation sample of the water-based ink was printed on photographic glossy paper BP71GA manufactured by Brother Industries.

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

Evaluation of color development Evaluation Criteria A: The cyan color is sufficiently expressed.
C: A cyan color cannot be expressed.

(B) Bronzing evaluation The gradation sample was visually observed, and whether or not bronzing occurred was evaluated according to the following evaluation criteria.

Bronzing Evaluation Evaluation A: No bronzing is observed.
B: Slight bronzing is observed, but there is no practical problem.
C: Significant bronzing is observed.

(C) Ozone resistance evaluation Among the gradation samples, a patch having an initial OD value of 1.0 was used as an evaluation patch. The OD value was measured with a spectrocolorimeter Spectrolino (light source: D ₆₅ ; field of view: 2 °; status A) manufactured by Gretag Macbeth. Using the ozone weather meter OMS-H manufactured by Suga Test Instruments Co., Ltd., the patch was allowed to stand for 40 hours under the conditions of an ozone concentration of 1 ppm, a bath temperature of 24 ° C., and a bath relative humidity of 60%. 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

Evaluation of ozone resistance Evaluation standard A: OD value decrease rate is less than 20% B: OD value decrease rate is 20% or more and less than 30% C: OD value decrease rate is 30% or more and less than 40% D: OD value decrease Rate is 40% or more

(D) Light resistance evaluation Among the gradation samples, a patch having an initial OD value of 1.0 was used as an evaluation patch. The OD value was measured with a spectrocolorimeter Spectrolino (light source: D ₆₅ ; field of view: 2 °; status A) manufactured by Gretag Macbeth. Using a Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd., the patch was irradiated with xenon lamp light for 100 hours under the conditions of a bath temperature of 23 ° C., a bath relative humidity of 50%, and an illuminance of 81 klx. 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 Evaluation standard A: OD value reduction rate is less than 20% B: OD value reduction rate is 20% or more and less than 30% C: OD value reduction rate is 30% or more and less than 40% D: OD value reduction rate But over 40%

(E) Evaluation of jetting stability Using a digital multifunction device DCP-385C equipped with an inkjet printer manufactured by Brother Industries, Ltd., 100 million dots (about 3 million dots) on office paper W (recording paper) manufactured by Fujitsu Coalco, Ltd. Million) continuous recording. The results of the continuous recording were evaluated according to the following evaluation criteria. Non-ejection is a state in which the nozzles of the inkjet head are clogged and the aqueous ink is not ejected. The discharge bend is a state in which a part of the nozzles of the ink jet head is clogged and the water-based ink is not discharged perpendicularly to the recording paper but is discharged obliquely.

Evaluation of jetting stability Evaluation standard A: During continuous recording, there was no non-ejection and no ejection bending.
B: During continuous recording, there was a slight non-ejection or ejection curve, but the non-ejection or ejection curve was recovered by purging 5 times or less.
C: During continuous recording, there were many non-ejections and ejection bends, and both the non-ejections and ejection bends were not recovered by 5 purges.

(F) Comprehensive evaluation About each water-based ink, comprehensive evaluation was performed from the result of said (a)-(e) according to the following evaluation criteria.

Overall Evaluation Evaluation Criteria G: All evaluation results were A or B.
NG: C or D was found in any of the evaluation results.

  Table 1 shows the compositions and evaluation results of the water-based inks of Examples and Comparative Examples.

  As shown in Table 1, the evaluation results were good in the examples in which the dye (1) and the dye (2) were used in combination. In Examples 7 to 10 in which the same conditions except for the weight ratio of the dye (1) and the dye (2) were used, the dye (1): dye (2) = 70: 30 to 95: 5 (weight ratio) In Examples 8 and 9, both bronzing and ozone resistance were very good. In Examples 11 to 14 in which the same conditions except for the total amount of dyes were used, in Examples 12 and 13 in which the total amount of dyes was 2 to 6% by weight, bronzing, ozone resistance and jet stability were extremely high. It was good.

  On the other hand, in the comparative example 1 which does not contain dye (2), color development and bronzing were inferior. In Comparative Example 2 which did not contain the dye (1), the ozone resistance was inferior. In place of the dye (2), C.I. I. In Comparative Example 3 using Acid Blue 9, ozone resistance and light resistance were remarkably inferior. In place of the dye (2), C.I. I. In Comparative Example 4 using Acid Blue 74, color developability was inferior, and ozone resistance and light resistance were remarkably inferior. In place of the dye (1), C.I. I. In Comparative Example 5 using Acid Blue 9, ozone resistance and light resistance were remarkably inferior. In place of the dye (1), C.I. I. In Comparative Example 6 using Acid Blue 74, color developability was inferior, and ozone resistance and light resistance were remarkably inferior.

  As described above, the water-based ink of the present invention is excellent in all the performances of color development, bronzing, ozone resistance and light resistance. The use of the water-based ink of the present invention is not particularly limited, and can be widely applied to various ink jet recordings.

DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus 2 Ink cartridge 3 Ink discharge means (inkjet head)
4 Head unit 5 Carriage 6 Drive unit 7 Platen roller 8 Purge device

Claims (5)

A water-based ink for inkjet recording comprising a colorant, water and a water-soluble organic solvent,
An aqueous ink for ink jet recording, wherein the colorant comprises the following dye (1) and dye (2).
Dye (1): Dye represented by general formula (1) (2): C.I. I. Direct Blue 86

In general formula (1),
Each of the rings A ₁ , A ₂ and A ₃ is at least one selected from the group consisting of a benzene ring, a 2,3-pyridine ring and a 3,2-pyridine ring, and the rings A ₁ , A ₂ And at least one of A ₃ is a 2,3-pyridine ring or a 3,2-pyridine ring, and the rings A ₁ , A ₂ and A ₃ may be the same or different;
l satisfies 0 ≦ l ≦ 4, m satisfies 0 ≦ m ≦ 4, n satisfies 0 ≦ n ≦ 4, and l, m, and n satisfy 0 ≦ l + m + n ≦ 4,
z is an integer satisfying 1 ≦ z ≦ 3,
R ₁ is a linear alkyl group having 1 to 6 carbon atoms. The water-based ink for inkjet recording according to claim 1, wherein a weight ratio of the dye (1) to the dye (2) in the water-based ink is dye (1): dye (2) = 70: 30 to 95: 5. . The water-based ink for ink-jet recording according to claim 1 or 2, wherein the total amount of the dye (1) and the dye (2) is 2% by weight to 6% by weight with respect to the total amount of the water-based ink. An ink cartridge comprising an aqueous ink for inkjet recording, wherein the aqueous ink is the aqueous ink for inkjet recording according to any one of claims 1 to 3. An ink jet recording apparatus that includes an ink storage unit and an ink discharge unit, and discharges ink stored in the ink storage unit by the ink discharge unit, wherein the ink storage unit stores the ink cartridge according to claim 4. An ink jet recording apparatus.

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