JP2012149221A - Ink composition, inkjet recording ink, and inkjet recording method - Google Patents

Abstract

The ink composition, ink for ink jet recording, and recording method of the present invention can control ink physical properties such as surface tension, improve ink permeability to image receiving paper, and prevent ink bleeding and color migration. it can. Provided are an ink composition, an ink for ink jet recording, and a recording method excellent in metal-like gloss and storage stability of a printed material from the viewpoint of further improving the image quality.
An ink composition containing at least a first color material and a second color material, wherein the first color material is a water-soluble azo dye, and the second color material. Is a dye comprising a heterocyclic compound, and the content (% by mass) of the second color material in the ink composition is the content (% by mass) of the first color material in the ink composition. The ink composition is characterized in that the mass ratio is 0.001 or more and 1.0 or less, and the content of transition metal ions in the ink is 0.0001 mmol / l to 0.1 mmol / l. object.
[Selection figure] None

Description

  The present invention relates to an ink composition, an ink for ink jet recording, and an ink jet recording method using the ink composition having high quality of a recorded image, excellent ejection stability, and excellent storage stability of the obtained image.

In recent years, with the spread of computers, ink jet printers are widely used for printing on paper, film, cloth and the like not only in offices but also at home.
Ink jet recording methods include a method of ejecting droplets by applying pressure with a piezo element, a method of ejecting droplets by generating bubbles in ink by heat, a method of using ultrasonic waves, or a droplet by electrostatic force. There is a method of sucking and discharging. As these inks for inkjet recording, water-based inks, oil-based inks, or solid (melting type) inks are used. Among these inks, water-based inks are mainly used from the viewpoints of production, handleability, odor, safety, and the like.

The colorant used in these inks for ink jet recording has high solubility in solvents, high density recording, good hue, light, heat, air, water and chemicals. Excellent fastness, good fixability to image-receiving materials, good bleeding, excellent ink storage, no toxicity, high purity, and availability at low cost. It is requested. However, it is extremely difficult to search for colorants that meet these requirements at a high level.
Up to now, the performance of ink for ink jet recording has been improved. Patent Document 1 discloses that a specific pyrazolyl azo dye can satisfy both a good hue required for an ink jet recording ink and a high fastness. Patent Documents 2 to 4 also describe specific pyrazolyl azo dyes. Patent Document 5 discloses that the fastness of a dye can be suppressed by setting the transition metal ion concentration in an ink containing an azo dye having a specific structure to a specific concentration or less.

JP 2004-083903 A JP 2005-264085 A JP 2007-224276 A JP 2006-57062 A Japanese Patent No. 3844340

As a result of further research in recent years, high-speed printing suitability is cited as a performance required for ink jet recording ink. For this purpose, it is necessary to control ink physical properties such as surface tension, improve the ink permeability to the image receiving paper, and prevent ink bleeding and color transfer. At the same time, from the viewpoint of higher image quality, the metallic luster of prints, the so-called bronzing phenomenon, has been improved at a high level, and further excellent storage stability has been required.
However, there is no disclosure in Patent Documents 1 and 2 regarding solutions for penetrability of ink into image receiving paper, bronze gloss of printed matter, and storage stability.
The problem to be solved by the present invention is to provide an ink composition, an ink jet recording ink, and a recording method that have excellent permeability to an image receiving paper, suppress bronze gloss of a printed matter, and have excellent storage stability. is there.

  The object of the present invention has been achieved by the following [1] to [12].

（一般式（Ｙ）中、Ｍはそれぞれ独立に水素原子またはカチオンを表し、Ｍがカチオンを表す場合はＬｉ^＋イオン、Ｎａ^＋イオン、Ｋ^＋イオンまたはＮＨ_４ ^＋イオンを表す。）

（群Ａ中、Ｍはそれぞれ独立に水素原子またはカチオンを表し、Ｍがカチオンを表す場合はＬｉ^＋イオン、Ｎａ^＋イオン、Ｋ^＋イオンまたはＮＨ_４ ^＋イオンを表す。）
〔２〕
前記群Ａより選択される化合物が、１、２、３及び８から選ばれる少なくとも１種である〔１〕に記載のインク組成物。
〔３〕
前記一般式（Ｙ）で表される化合物において、Ｍの主成分がＫ^＋イオンであり、群Ａより選択される化合物において、Ｍの主成分がＫ^＋イオンである〔１〕又は〔２〕に記載のインク組成物。
〔４〕
前記一般式（Ｙ）で表される化合物及び群Ａより選択される化合物におけるＭが全てＫ^＋イオンである〔１〕〜〔３〕のいずれか１項に記載のインク組成物。
〔５〕
前記第１の色材の含有量が、インク組成物全質量を基準として、１質量％以上１５質量％以下である〔１〕〜〔４〕のいずれか１項に記載のインク組成物。〔６〕
前記第２の色材のインク組成物中における含有量（質量％）が、前記第１の色材のインク組成物中における含有量（質量％）に対して、質量比率で、０．００１以上０．２以下である〔１〕〜〔５〕のいずれか１項に記載のインク組成物。
〔７〕
前記第２の色材の含有量が、インク組成物全質量を基準として、０．０１質量％以上１．１質量％以下である〔１〕〜〔６〕のいずれか１項に記載のインク組成物。
〔８〕
前記遷移金属イオンがＴｉ，Ｃｒ，Ｍｎ，Ｆｅ，Ｃｏ，Ｎｉ，Ｃｕ，Ｚｎ，Ｍｏ，Ｐｄ，Ａｇ，Ｃｄ，及びＨｇのイオンより選択される少なくとも1種であることを特徴とする〔１〕〜〔７〕のいずれか一項に記載のインク組成物。
〔９〕
前記遷移金属イオンの含有量が０．０１ｍｍｏｌ／ｌ〜０．１ｍｍｏｌ／ｌであることを特徴とする〔１〕〜〔８〕のいずれか一項に記載のインク組成物。
〔１０〕
前記染料を０．２〜２０質量％含有することを特徴とする〔１〕〜〔９〕のいずれか一項に記載のインク組成物。
〔１１〕
〔１〕〜〔１０〕のいずれか一項に記載のインク組成物を用いることを特徴とするインクジェット記録用インク。
〔１２〕
支持体上に白色無機顔料粒子を含有する受像層を有する受像材料にインク滴を記録信号に応じて吐出させ、受像材料上に画像を記録するインクジェット記録方法であって、インク滴が〔１〕〜〔１０〕のいずれか一項に記載のインク組成物からなることを特徴とするインクジェット記録用インク。 [1]
An ink composition containing at least a first color material and a second color material,
The first color material is a compound represented by the following general formula (Y), the second color material is at least one compound selected from the following group A, and the second color The content (mass%) of the material in the ink composition is 0.001 or more and 1.0 or less in mass ratio with respect to the content (mass%) of the first color material in the ink composition. An ink composition, wherein the content of transition metal ions in the ink is 0.0001 mmol / l to 0.1 mmol / l.
General formula (Y)

(In the general formula (Y), each M independently represents a hydrogen atom or a cation. When M represents a cation, each represents a Li ⁺ ion, a Na ⁺ ion, a K ⁺ ion, or an NH ₄ ⁺ ion.)

(In group A, M independently represents a hydrogen atom or a cation, and when M represents a cation, it represents a Li ⁺ ion, a Na ⁺ ion, a K ⁺ ion, or an NH ₄ ⁺ ion.)
[2]
The ink composition according to [1], wherein the compound selected from Group A is at least one selected from 1, 2, 3 and 8.
[3]
In the compound represented by the general formula (Y), the main component of M is K ⁺ ion, and in the compound selected from Group A, the main component of M is K ⁺ ion [1] or [2] The ink composition described in 1.
[4]
The ink composition according to any one of [1] to [3], wherein all Ms in the compound represented by the general formula (Y) and the compound selected from Group A are K ⁺ ions.
[5]
The ink composition according to any one of [1] to [4], wherein the content of the first color material is 1% by mass or more and 15% by mass or less based on the total mass of the ink composition. [6]
The content (mass%) of the second color material in the ink composition is 0.001 or more in terms of mass ratio with respect to the content (mass%) of the first color material in the ink composition. The ink composition according to any one of [1] to [5], which is 0.2 or less.
[7]
The ink according to any one of [1] to [6], wherein the content of the second color material is 0.01% by mass or more and 1.1% by mass or less based on the total mass of the ink composition. Composition.
[8]
The transition metal ion is at least one selected from ions of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, and Hg [1] -The ink composition as described in any one of [7].
[9]
The ink composition according to any one of [1] to [8], wherein the content of the transition metal ion is 0.01 mmol / l to 0.1 mmol / l.
[10]
The ink composition according to any one of [1] to [9], comprising 0.2 to 20% by mass of the dye.
[11]
[1] An ink for ink jet recording using the ink composition according to any one of [10].
[12]
An ink jet recording method for recording an image on an image receiving material by ejecting ink droplets onto an image receiving material having an image receiving layer containing white inorganic pigment particles on a support in accordance with a recording signal. An ink for ink jet recording comprising the ink composition according to any one of [10] to [10].

  The ink composition, ink for ink jet recording, and recording method of the present invention can control ink physical properties such as surface tension, improve ink permeability to image receiving paper, and prevent ink bleeding and color transfer. From the standpoint of further improving the image quality, it is possible to provide an ink composition, an ink jet recording ink and a recording method which improve the metallic luster of the printed matter, the so-called bronzing phenomenon, at a high level and have excellent storage stability.

  Hereinafter, the present invention will be described in detail.

The present inventors have made studies in order to solve the above technical problem and have arrived at the present invention. That is, the ink composition of the present invention is
An ink composition containing at least a first color material and a second color material,
The first color material is a compound represented by the following general formula (Y), the second color material is at least one compound selected from the following group A, and the second color The content (mass%) of the material in the ink composition is 0.001 or more and 1.0 or less in mass ratio with respect to the content (mass%) of the first color material in the ink composition. The content of transition metal ions in the ink is 0.0001 mmol / l to 0.1 mmol / l.
A transition metal containing a compound represented by the general formula (Y) as the first color material and at least one compound selected from the following group A as the second color material in a specific mass ratio; By adjusting the ion content to 0.0001 mmol / l to 0.1 mmol / l, the penetrability of the ink composition into the image receiving paper is improved, the bronze gloss of the printed material is improved, and the storage stability is excellent.

(First color material)
[Compound Represented by General Formula (Y)] The azo dye that is the first colorant used in the ink composition of the present invention is represented by the general formula (Y). Below, the compound represented by general formula (Y) is demonstrated. The compound represented by the general formula (Y) is a water-soluble azo dye (yellow). In addition, the compound represented by the general formula (Y) may be referred to as “azo dye”.
General formula (Y)

(In the general formula (Y), each M independently represents a hydrogen atom or a cation. When M represents a cation, each represents a Li ⁺ ion, a Na ⁺ ion, a K ⁺ ion, or an NH ₄ ⁺ ion.)

M represents a hydrogen atom, Li ⁺ ion, Na ⁺ ion, K ⁺ ion, or NH ₄ ⁺ ion, particularly preferably Na ⁺ ion, K ⁺ ion, or NH ₄ ⁺ ion, and more preferably Na ⁺ ion or K ⁺ ion. Of these, K ⁺ ions are most preferable. In the dye represented by the general formula (Y), it is preferable that at least one of M is K ⁺ ion, more preferably the counter cation is K ⁺ ions as the main component of the M, all M K More preferably, it is a ⁺ ion.
The dye represented by formula (Y) may be in the form of a mixed salt in which a plurality of types of M are present. In the case of a mixed salt, the M of the dye represented by the formula (Y) contained in the ink has a molar fraction of preferably 50 to 100%, more preferably 80 to 100%, and particularly 90 of these. It is preferred that ~ 100% of M is K ⁺ ions. As M other than K ⁺ ions, Na ⁺ ions and NH ₄ ⁺ ions are preferable, and Na ⁺ ions are more preferable.

Further, it is most preferable that M of the dye represented by the formula (Y) contained in the ink composition, not the mixed salt, is a K ⁺ ion. Since all M is a K ⁺ ion, in a molecular dispersion state dissolved in an aqueous solution or an ink solution, a carboxy group that is an ionic hydrophilic group or a salt thereof (—CO ₂ M) is dissociated to —CO _2. By exchanging cation species in an ionized state of ⁻ and M ⁺ , it is easy to suppress the formation of a salt state that is less soluble in an aqueous solution or ink solution and precipitation in the salt state of the colorant. This is because such an effect is obtained.
Among the compounds of the general formula (Y), it is preferable to use a compound of the following formula (Y-1).
Formula (Y-1)

  The dyes represented by the general formula (Y) and the formula (Y-1) can be synthesized by a general synthesis method. For example, as described in JP-A-2004-083903, [0066] and [0067] It can be synthesized in the same way as the method.

[Group A]
The ink composition of the present invention comprises, in addition to the compound of the general formula (Y) or the compound of the formula (Y-1) described above used as the first color material, the storage stability of the ink composition, It is necessary to contain a second color material having the characteristics of excellent colorability of ink and image fastness of printed matter. In the present invention, at least one compound selected from the following group A is used as the second color material. Among at least one compound selected from the following group A, it is particularly preferable to use compound 1, 2, 3, 5, 6 or 8 in group A, and to use 1, 2, 3, 6 or 8 More preferably, 1, 2, 3 or 8 is more preferably used.

  In the present invention, as the second coloring material, at least one compound selected from the group A may be used alone or in combination. In the present invention, it is preferable to use a combination of 1, 2, 3, 5, 6, and 8 as the second coloring material, and it is preferable to use a combination of 1, 2, 3, 6, and 8. More preferably, it is more preferable to use a combination of 1, 2, 3, and 8.

  Moreover, the synergistic effect is exhibited by using at least 1 type of compound selected from the following group A in combination with the compound of the said general formula (Y), The following effects can be acquired. That is, by including these color materials, not only can the yellow ink composition have a high coloring power, but also an image with excellent light resistance can be obtained, and in addition, the ink supply path can be prevented from being clogged. Storage stability can be fully satisfied. Hereinafter, these general formulas will be described.

(In group A, M independently represents a hydrogen atom or a cation, and when M represents a cation, it represents a Li ⁺ ion, a Na ⁺ ion, a K ⁺ ion, or an NH ₄ ⁺ ion.)
M in at least one compound selected from the group A represents a hydrogen atom, Li ⁺ ion, Na ⁺ ion, K ⁺ ion, or NH ₄ ⁺ ion, and Na ⁺ ion, K ⁺ ion, NH ₄ ⁺ ion. Are preferred, Na ⁺ ions and K ⁺ ions are preferred, and K ⁺ ions are more preferred. In at least one compound selected from the group A, it is preferable that the main component of the counter cation M is K ⁺ ions, it is more preferred that all of M is K ⁺ ion.

The at least one compound selected from group A may be in the form of a mixed salt in which a plurality of types of M are present. In the case of a mixed salt, the M selected from the group A contained in the ink composition preferably has a molar fraction of 50 to 100%, more preferably 80 to 100%, and more preferably 90 to 90%. Preferably 100% of M is a K ⁺ ion. As M other than K ⁺ ions, Na ⁺ ions and NH ₄ ⁺ ions are preferable, and Na ⁺ ions are more preferable.

Further, it is particularly preferable that M of the compound selected from all the groups A contained in the ink composition, not the mixed salt, is K ⁺ . Since all M is a K ⁺ ion, in a molecular dispersion state dissolved in an aqueous solution or an ink solution, a carboxy group that is an ionic hydrophilic group or a salt thereof (—CO ₂ M) is dissociated to —CO _2. By exchanging cation species in an ionized state of ⁻ and M ⁺ , it is easy to suppress the formation of a salt state that is less soluble in an aqueous solution or ink solution and precipitation in the salt state of the colorant. This is because such an effect is obtained.
The compound selected from Group A can be synthesized by a general synthesis method. For example, the diazo component and the coupling component described in JP-A-2004-083903 are changed and combined in various ways. Y) or similar to formula (Y-1).

In the present invention, in the compound represented by the general formula (Y), the main component of the counter cation M is K ⁺ ion, and in the compound selected from the group A, the main component of the counter cation M is K ⁺ ion. It is preferable that Here, the main component of the counter cation M means ions that occupy 80% or more, preferably 90% or more of all the counter cations M.
If the main component of the counter cation M of the ionic hydrophilic group of the compound represented by the general formula (Y) and the compound selected from the group A is K ⁺ ion, the solubility in the ink composition is increased, This is because salt formation and precipitation can be suppressed and the storage stability of the ink composition can be greatly improved.
Moreover, it is more preferable that all of M in the compound represented by the general formula (Y) and the compound selected from Group A are K ⁺ ions. This is because the storage stability of the ink composition can be greatly improved.

[Color material verification method]
In order to verify whether or not the color material used in the present invention is contained in the ink composition and the ink, the following verification methods (1) to (3) using liquid chromatograph mass spectrometry (LC-MS) are used. Applicable.
(1) Peak retention time (2) Maximum absorption wavelength for peak of (1) (3) m / z (posi), m / z (nega) of mass spectrum for peak of (1)

  The analysis conditions of liquid chromatograph mass spectrometry are as follows. A liquid (ink) diluted about 1,000 times with pure water was used as a measurement sample. And the analysis by a liquid chromatograph mass spectrometry was performed on the following conditions, and the retention time (retention time) of a peak and a Mass actual value peak were measured.

<Measurement conditions of liquid chromatograph mass spectrometry (LC-MS)>
・ Device: Agilent 1100 (manufactured by Agilent Technologies)
Column: YMC AM-312 ID 6.0 mm x length 150 mm (manufactured by YMC)
-Eluent: Liquid A Ultrapure water + 0.1% acetic acid, 0.2% triethylamine
Liquid B Methanol + 0.1% acetic acid, 0.2% triethylamine Mobile phase and gradient conditions: (Table 1)
In Table 1, B.I. Conc. Represents the concentration of the B liquid.

The analysis conditions of the mass spectrum are as shown below. About the obtained peak, a mass spectrum is measured on condition of the following, and m / z detected most strongly is measured with respect to each of posi and negative.
・ Apparatus: Applied Biosystems ^™ QSTAR pulser (manufactured by Life Technology)
・ Ionization method: ESI (posi)
・ Capillary voltage: 3.5 kV
-Desolvent gas: 300 ° C
-Ion source temperature: 120 ° C
・ Detection method: TOF-MS
-Detection range: 120-1500

Under the above method and conditions, as representative examples of the respective color materials, the first color material compound (Y-1) and the compounds 1 to 8 (M = K) in the second color material group A were measured. Went. As a result, the obtained retention time and Mass measured value {m / z (posi)} are shown in Table 2. When the ink composition and the ink are measured under the same method and conditions as described above and correspond to the values shown in Table 2, it can be determined that they correspond to the compounds used in the present invention.
M can be verified, for example, by measurement using an ion chromatograph.
Ion chromatograph measurement conditions:
Apparatus: Personal ion analyzer PIA-1000 (manufactured by Shimadzu Corporation)
Column: Semi-micro column for cation analysis Shim-pack IC-C3 (S) (inner diameter 2 mm × length 100 mm)
Mobile phase: 2.5 mM oxalic acid aqueous solution Column temperature: 35 ° C.
Flow rate: 0.2 mL / min

(Ink composition) [Coloring material content]
The content (% by mass) of the first color material in the ink composition is preferably 1% by mass or more and 15% by mass or less based on the total mass of the ink composition. Further, the content (% by mass) of the first color material is preferably 8% by mass or more and 12% by mass or less based on the total mass of the ink composition.
The ink composition of the present invention can be a concentrated aqueous solution containing a colorant at a high concentration as an ink raw material. The concentration of the colorant in the concentrated aqueous solution is preferably 15% by mass or less, and preferably 12% by mass or less from the viewpoint of dye stability over time and ease of handling (viscosity). Improvement in dye stability over time and transportation costs From the viewpoint of suppressing the above, the concentration is preferably 8% by mass or more.
The ink composition of the present invention can also be used as an inkjet ink. The colorant concentration of the inkjet ink is preferably 1 to 12% by mass, more preferably 2 to 8% by mass, and particularly preferably 3 to 6% by mass in terms of the ink viscosity and the density of the printed matter.
The content of the second color material [at least one compound selected from group A] in the ink composition is preferably as follows. That is, the content (% by mass) of the second color material is preferably 0.001% by mass or more and 2.0% by mass or less, and 0.005% by mass or more and 1% by mass based on the total mass of the ink composition. More preferably, it is 0.5 mass% or less, More preferably, it is 0.01 mass% or more and 1.1 mass% or less, Especially preferably, it is 0.05 mass% or more and 0.8 mass% or less.

In this case, the content of the second color material is more preferably as follows in relation to other color materials. When any one of at least one compound selected from Group A is used alone, the content thereof, and when two or more selected from these are used in combination, the total content thereof is within the above range. It is preferable to satisfy the requirements. By setting the content of the first color material and / or the second color material in the above range, not only the light resistance and color tone of the image are satisfied, but also the ink composition such as storage stability and recording durability is added. The reliability of the ink used can also be satisfied.
Compound 1 in Group A is preferably contained in an amount of 0.001 to 1.0% by mass, more preferably 0.01 to 1.0% by mass, based on the total mass of the ink composition.
Compound 2 in Group A is preferably contained in an amount of 0.003 to 3.0% by mass, more preferably 0.1 to 3.0% by mass, based on the total mass of the ink composition.
Compound 3 in Group A is preferably contained in an amount of 0.001 to 1.0% by mass, more preferably 0.01 to 1.0% by mass, based on the total mass of the ink composition.
The compound 4 in the group A is preferably contained in an amount of 0.0 to 0.5% by mass based on the total mass of the ink composition.
The compound 5 in Group A is preferably contained in an amount of 0.0 to 0.5% by mass based on the total mass of the ink composition.
The compound 6 in the group A is preferably contained in an amount of 0.0 to 0.5% by mass based on the total mass of the ink composition.
The compound 7 in Group A is preferably contained in an amount of 0.0 to 0.5% by mass based on the total mass of the ink composition.
The compound 8 in group A is preferably contained in an amount of 0.002 to 2.0 mass%, more preferably 0.05 to 2.0 mass%, based on the total mass of the ink composition.

  The content (% by mass) of the second color material based on the total mass of the ink composition is a mass ratio with respect to the content (% by mass) of the first color material. / First coloring material) = 0.001 or more and 1.0 or less.

  Further, in the present invention, the content (mass%) of the second color material is a mass ratio with respect to the content (mass%) of the first color material ((second color material / first Colorant) = 0.001 or more and 0.3 or less is preferable. Predicted from the combination of the solubility and light resistance of the first color material and the solubility and light resistance of the second color material by configuring the mass ratio of the color material content to be in the above range. Images with a high level of lightfastness can be formed that far exceed the performance that is achieved. In addition, an image having a more preferable color tone can be obtained. The content (mass%) of the second color material is a mass ratio with respect to the content (mass%) of the first color material, (second color material / first color material) = 0. It is more preferably 001 or more and 0.2 or less, further preferably 0.01 or more and 0.2 or less, and further preferably 0.02 or more and 0.12 or less. By setting the mass ratio of the content of the color material within this range, an image having a particularly high level of light resistance can be formed even in the mass ratio of the content described above. Furthermore, an image having a particularly preferable color tone can be obtained, and in addition, the reliability as an ink can be sufficiently satisfied.

  When the mass ratio is 0.001 or more, the storage stability of the ink solution is improved, and when it is 1.0 or less, the aqueous solution stability of the ink composition is excellent. By configuring the mass ratio of the color material content to be in the above range, the solubility and image fastness of the first color material and the solubility and image fastness of the second color material It is possible to achieve a high level of ink storage stability and image fastness of printed matter that exceed the performance predicted from the combination. Further, an image having a preferable color tone can be obtained, and the reliability as an ink can be satisfied.

  The reason why a synergistic effect can be achieved by using the first color material and the second color material at a specific mass ratio, and it is possible to achieve both the storage stability of the ink exceeding the prediction and the image fastness of the printed matter. The inventors presume as follows. Since the first color material tends to have low solubility in an aqueous medium from the beginning, when an ink using an ink composition containing these compounds is applied to a recording medium, the color material is immediately assembled or immediately after that. Aggregation occurs. The association or aggregation tends to improve the fastness of the color material on the recording medium on which the image is formed. On the other hand, however, excessive association or aggregation may reduce the solubility in aqueous solutions and ink solutions. On the other hand, by causing the first color material and the second color material to coexist, the first color material forms an optimal association or aggregation state with respect to light resistance on the recording medium. It is considered that the light resistance of the image has been improved.

  In addition, the inventors of the present invention have the reason why a synergistic effect is achieved by using the first color material and the second color material at a specific mass ratio, and the reliability of the ink using the ink composition is achieved. Guesses as follows. As described above, impurities that are considered to have eluted from the ink cartridge and the members constituting the ink supply path are mixed in the ink, and the ink supply path is clogged, the ink supply characteristics are degraded, and the ink storage stability is improved. May cause a drop. As a result of the study, the present inventors have found that the second coloring material similar to the first coloring material structure is allowed to coexist in the ink, so that the crystallization of the first coloring material can be achieved without reducing the coloring power of the ink. It is believed that the suppression could be imparted and the storage stability of the ink could be greatly improved. In other words, with regard to the reliability of the ink, which was difficult to achieve by using only the first color material as the color material, the combined use of the second color material provides an effect that exceeds the expectation, and sufficient reliability. Sex can be achieved.

The yellow dye used in the present invention has an excellent forced fading rate constant for ozone gas. The measurement of the forced fading rate constant for ozone gas is the color of the main spectral absorption region of the ink obtained by printing only the ink on the reflective image receiving medium, and the reflection density measured through the status A filter is 0. A colored region having a density of .90 to 1.10. This image is faded using an ozone fading tester that constantly maintains an ozone concentration of 5 mg / L, the time until the concentration reaches 80% of the initial concentration is measured, and the reciprocal of this time [hour ⁻¹ ] is calculated. The amber reaction rate constant is obtained on the assumption that the relationship between the amber color density and the time follows the rate equation of the first order reaction. Therefore, the obtained fading speed constant is the fading speed constant of the colored area printed by the ink, but in this specification, this value is used as the fading speed constant of the ink.

  As the test print patch, a patch printed with a black square symbol of JIS code 2223, a stepped color patch of Macbeth chart, or any other step density patch that can obtain a measurement area can be used.

  The reflection density of the reflected image (stepped color patch) printed for measurement is the density obtained with the measurement light that has passed through the status A filter by a densitometer that satisfies the international standard ISO5-4 (geometric condition of reflection density). It is.

  A test chamber for forced fading rate constant measurement for ozone gas is provided with an ozone generator (for example, a high-pressure discharge system that applies an alternating voltage to dry air) that can maintain the internal ozone gas concentration at 5 mg / L constantly, The aeration temperature is adjusted to 25 ° C.

  This forced fading rate constant is determined by the susceptibility to oxidation by an oxidizing atmosphere in the environment, such as photochemical smog, automobile exhaust, organic vapor from painted surfaces and carpets of furniture, and gas generated in the frame of a bright room. An index that represents these oxidizing atmospheres with ozone gas.

  Further, the total content (% by mass) of the first color material and the second color material in the ink composition is 1.00% by mass or more and 12.00% by mass based on the total mass of the ink composition. %, Preferably 3.00 mass% or more and 8.0 mass% or less. If the total content is 1.00% by mass or more, light fastness and color developability are sufficiently obtained, and if the total content is 12.00% by mass or less, insoluble matter is precipitated in the ink. Excellent inkjet discharge characteristics.

  In addition, when the ink composition of the present invention is a yellow ink for ink jet recording, the preferred color tone for the yellow ink means the following two things. That is, it means that an image formed using only yellow ink is not reddish or greenish. In addition to this, when forming a secondary color image formed using yellow ink, that is, a red or green image, a color tone that does not greatly lose the red and green color reproduction ranges. It means having.

  The ink composition of the present invention (preferably ink for inkjet recording) includes a water-soluble azo dye represented by the general formula (Y) as a first color material, and a group A as the second color material. Other dyes may be used in combination with the selected at least one compound and the compound represented by the general formula (2) in order to adjust the color tone and balance the performance. For the purpose of obtaining a full-color image, an ink containing another pigment may be used in combination with the ink composition of the present invention. Examples of dyes and pigments that can be used in combination include the following.

  As yellow dyes, for example, phenols, naphthols, anilines, pyrazolones, pyridones, aryl or heteryl azo dyes having open-chain active methylene compounds as coupling components; for example, open-chain active methylene compounds as coupling components Azomethine dyes; methine dyes such as benzylidene dyes and monomethine oxonol dyes; quinone dyes such as naphthoquinone dyes and anthraquinone dyes; And dyes, acridine dyes, acridinone dyes and the like. These dyes may be those that exhibit yellow only after a part of the chromophore is dissociated, in which case the counter cation may be an alkali metal or an inorganic cation such as ammonium, pyridinium, It may be an organic cation such as a quaternary ammonium salt, and may further be a polymer cation having them in a partial structure.

  Examples of magenta dyes include, for example, aryl or heteryl azo dyes having phenols, naphthols, and anilines as coupling components; azomethine dyes having pyrazolones and pyrazolotriazoles as coupling components; for example, arylidene dyes, styryl dyes, and merocyanine Dyes, methine dyes such as oxonol dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, quinone dyes such as naphthoquinone, anthraquinone, anthrapyridone, etc. Examples thereof include ring dyes. These dyes may exhibit magenta only after part of the chromophore is dissociated, and the counter cation in that case may be an alkali metal or an inorganic cation such as ammonium, pyridinium, It may be an organic cation such as a quaternary ammonium salt, and may further be a polymer cation having them in a partial structure.

Examples of the cyan dye include azomethine dyes such as indoaniline dyes and indophenol dyes; polymethine dyes such as cyanine dyes, oxonol dyes and merocyanine dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes and xanthene dyes; phthalocyanine Dyes; anthraquinone dyes; for example, aryl or heteryl azo dyes having phenols, naphthols and anilines as coupling components, and indigo / thioindigo dyes. These dyes may exhibit cyan only after a part of the chromophore is dissociated, and the counter cation in that case may be an alkali metal or an inorganic cation such as ammonium, pyridinium, It may be an organic cation such as a quaternary ammonium salt, and may further be a polymer cation having them in a partial structure.
Also, black dyes such as polyazo dyes can be used.

  Examples of water-soluble dyes include direct dyes, acid dyes, food dyes, basic dyes, and reactive dyes. Preferred examples include C.I. I. Direct Red 2, 4, 9, 23, 26, 31, 39, 62, 63, 72, 75, 76, 79, 80, 81, 83, 84, 89, 92, 95, 111, 173, 184, 207, 211, 212, 214, 218, 21, 223, 224, 225, 226, 227, 232, 233, 240, 241, 242, 243, 247C. I. Direct violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100, 101C. I. Direct yellow 8, 9, 11, 12, 27, 28, 29, 33, 35, 39, 41, 44, 50, 53, 58, 59, 68, 86, 87, 93, 95, 96, 98, 100, 106, 108, 109, 110, 130, 132, 142, 144, 161, 163C. I. Direct Blue 1, 10, 15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80, 84, 86, 87, 90, 98, 106, 108, 109, 151, 156, 158, 159, 160, 168, 189, 192, 193, 194, 199, 200, 201, 202, 203, 207, 211, 213, 214, 218, 225, 229, 236, 237, 244, 248, 249, 251, 252, 264, 270, 280, 288, 289, 291C. I. Direct Black 9, 17, 19, 22, 32, 51, 56, 62, 69, 77, 80, 91, 94, 97, 108, 112, 113, 114, 117, 118, 121, 122, 125, 132, 146, 154, 166, 168, 173, 199 C.I. I. Acid Red 35, 42, 52, 57, 62, 80, 82, 111, 114, 118, 119, 127, 128, 131, 143, 151, 154, 158, 249, 254, 257, 261, 263, 266, 289, 299, 301, 305, 336, 337, 361, 396, 397 C.I. I. Acid Violet 5, 34, 43, 47, 48, 90, 103, 126C. I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76, 79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199, 218, 219, 222, 227C. I. Acid Blue 9, 25, 40, 41, 62, 72, 76, 78, 80, 82, 92, 106, 112, 113, 120, 127: 1, 129, 138, 143, 175, 181, 205, 207, 220, 221, 230, 232, 247, 258, 260, 264, 271, 277, 278, 279, 280, 288, 290, 326C. I. Acid Black 7, 24, 29, 48, 52: 1, 172C. I. Reactive Red 3, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40, 41, 43, 45, 49, 55C. I. Reactive violet 1, 3, 4, 5, 6, 7, 8, 9, 16, 17, 22, 23, 24, 26, 27, 33, 34C. I. Reactive Yellow 2, 3, 13, 14, 15, 17, 18, 23, 24, 25, 26, 27, 29, 35, 37, 41, 42C. I. Reactive Blue 2, 3, 5, 8, 10, 13, 14, 15, 17, 18, 19, 21, 25, 26, 27, 28, 29, 38C. I. Reactive Black 4, 5, 8, 14, 21, 23, 26, 31, 32, 34C. I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36, 38, 39, 45, 46C. I. Basic violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35, 37, 39, 40, 48C. I. Basic Yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 39, 40C. I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 41, 45, 46, 47, 54, 57, 60, 62, 65, 66, 69, 71C. I. Basic black 8, etc. are mentioned.

Furthermore, pigments may be used in combination with the ink of the present invention.
As the pigment used in the present technology, commercially available pigments and known pigments described in various documents can be used. For literature, see the Color Index (The Society of
Dyers and Colorists), “Revised New Edition Pigment Handbook” edited by Japan Pigment Technology Association (1989), “Latest Pigment Applied Technology” CMC Publishing (1986), “Printing Ink Technology” CMC Publishing (1984), W. Herbst, K.M. Hunger co-authored, Industrial Organic Pigments (VCH Verlagsgesellschaft, published in 1993). Specifically, for organic pigments, azo pigments (azo lake pigments, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, indigo pigments, quinacridone Pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, etc.), dyed lake pigments (acid or basic dye lake pigments), azine pigments, etc. C.I. of yellow pigment I. Pigment Yellow 34, 37, 42, 53, and other red pigments such as C.I. I. Pigment Red 101, 108, C.I. I. Pigment Blue 27, 29, 17: 1, etc. I. Pigment Black 7, magnetite, and other white pigments such as C.I. I. Pigment White 4, 6, 18, 21 and the like.

  As a pigment having a preferable color tone for image formation, a phthalocyanine pigment, an anthraquinone-based indanthrone pigment (for example, CI Pigment Blue 60), and a dyed lake pigment-based triarylcarbonium pigment are preferable for a blue or cyan pigment. Phthalocyanine pigments (preferred examples include copper phthalocyanine such as CI Pigment Blue 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, monochloro or low chlorinated copper) Among the phthalocyanines and alnium phthalocyanines, the pigments described in European Patent No. 860475, the metal-free phthalocyanine which is CI Pigment Blue 16, the phthalocyanines whose central metals are Zn, Ni and Ti, among them, CI pigment is preferable. Bl e 15: 3, 15: 4 and aluminum phthalocyanine) are most preferred.

  For red to purple pigments, azo pigments (preferred examples include CI Pigment Red 3, 5, 11, 22, 38, 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 52: 1, 53: 1, 57: 1, 63: 2, 144, 146, and 184). I. Pigment Red 57: 1, 146, 184), quinacridone pigments (preferred examples include CI Pigment Red 122, 192, 202, 207, 209, CI Pigment Violet 19, 42, particularly preferred are CI Pigment Red 122), dyed lake pigment-based triarylcarbonium pigments (preferred examples include xanthene-based CI Pigment Red 81: 1, CI Pigment Violet). 1, 2, 3, 27, 39), dioxazine pigments (for example, CI Pigment Violet 23, 37), diketopyrrolopyrrole pigments (for example, CI Pigment Red 254), perylene Pigments (e.g. CI Pi ment Violet 29), anthraquinone pigments (e.g., C.I. Pigment Violet 5: 1, the 31, the 33), thioindigo (e.g. C.I. Pigment Red 38, the 88) is preferably used.

  Examples of yellow pigments include azo pigments (preferred examples include monoazo pigment-based CI Pigment Yellow 1, 3, 74, 98, disazo pigment-based CI Pigment Yellow 12, 13, 14, 16, 17, 83. Among them, preferred are benzidine type, such as CI Pigment Yellow 93, 94, 95, 128, 155 of synthetic azo type, CI Pigment Yellow 120, 151, 154, 156, 180 of benzimidazolone type. Compounds in which no compound is used as a raw material), isoindoline / isoindolinone pigments (preferred examples include CI Pigment Yellow 109, 110, 137, 139), quinophthalone pigments (preferred examples include CI Pigment). Yellow 13 8), and Frapantron pigments (for example, CI Pigment Yellow 24) are preferably used.

Preferred examples of the black pigment include inorganic pigments (preferably carbon black and magnetite as examples) and aniline black.
In addition, an orange pigment (such as CI Pigment Orange 13, 16) or a green pigment (such as CI Pigment Green 7) may be used.

The pigment that can be used in the present technology may be the aforementioned bare pigment or a surface-treated pigment. Surface treatment methods include resin or wax surface coating, surfactant deposition, reactive substances (eg radicals derived from silane coupling agents, epoxy compounds, polyisocyanates, diazonium salts, etc.) pigments A method of bonding to the surface is conceivable and is described in the following documents and patents.
(1) Properties and applications of metal soap (Sachishobo)
(2) Printing ink printing (CMC Publishing 1984)
(3) Latest pigment application technology (CMC Publishing 1986)
(4) U.S. Pat. Nos. 5,554,739 and 5,571,311 (5) JP-A Nos. 9-151342, 10-140065, 10-292143, and 11-166145 Self-dispersing pigments prepared by allowing a diazonium salt described in US Patent 4) to act on carbon black and encapsulated pigments prepared by the method described in Japanese Patent (5) above are used in inks. In particular, the dispersion stability can be obtained without using an extra dispersant.

In the present invention, the pigment may be further dispersed using a dispersant. Various known dispersants can be used in accordance with the pigment to be used, for example, a surfactant-type low-molecular dispersant or a polymer-type dispersant. Examples of the dispersant include those described in JP-A-3-69949, European Patent 549486 and the like. In addition, when a dispersant is used, a pigment derivative called a synergist may be added to promote adsorption of the dispersant to the pigment.
The particle size of the pigment that can be used in the present technology is preferably in the range of 0.01 to 10 μm after dispersion, and more preferably 0.05 to 1 μm.
As a method for dispersing the pigment, a known dispersion technique used in ink production or toner production can be used. Examples of the dispersing machine include vertical or horizontal agitator mills, attritors, colloid mills, ball mills, three roll mills, pearl mills, super mills, impellers, dispersers, KD mills, dynatrons, and pressure kneaders. Details are described in "Latest Pigment Application Technology" (CMC Publishing, 1986).

〔Metal ions〕
Next, metal ions contained in the ink according to the present invention will be described. The ink according to the present invention contains transition metal ions described later. Further, any monovalent cation selected from lithium, sodium, potassium and ammonium derived from the dye represented by the general formula (Y) may be contained.

  In addition, it is mixed as impurity cations from various additives, solvents, raw materials, additives such as reaction catalysts and devices in the synthesis process. In particular, transition metal ions have magnetism, complex formation, and hydration ions are easily colored, causing precipitation on the discharge head and nozzle clogging, and dullness of the formed image. Cause inhibition of paper penetration or excessive aggregation of the dye. This is particularly noticeable in pale yellow images, dimeric dyes having a large molecular weight, and dyes containing many heteroatoms. Although it is preferable to remove completely, the upper limit value and the lower limit value are determined by the balance between the effect and the efficiency.

[Transition metal ions]
The ink of the present invention is characterized in that the content of transition metal ions contained in the ink is 0.0001 mmol / l to 0.1 mmol / l. In order not to include transition metal ions as metal ions, avoid the use of metal containers in the process of dye synthesis, and make transition metal masking agents into metal ions free and then into alkali metal salts. It can be carried out by a method such as adding metal ions during synthesis to remove metal ions, or exchanging the produced dye.
It is also important to remove ions from the solvent used to prepare the ink. In particular, deionized water is preferably used for water as the main solvent.

  The content of transition metal ions contained in the ink of the present invention is 0.0001 mmol / l to 0.1 mmol / l, preferably 0.01 mmol / l to 0.1 mmol / l. By setting the transition metal ion content in the above range, the permeability of the inkjet recording ink to the image receiving paper is improved, the bronze gloss of the printed matter is improved, and the storage stability is excellent.

  Examples of the transition metal ions include at least one selected from ions of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, and Hg. More preferably, the total content of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, and Hg as transition metal ions contained in the ink is in the above range. More preferably, the total content of ions of Fe, Cr, Ni and Zn is in the above range. These transition metal ions can be derived from stainless steel and iron in reaction kettles and water pipes.

Next, the surfactant that can be contained in the ink jet recording ink of the present invention will be described.
Examples of the surfactant used in the present invention include anionic surfactants such as fatty acid salts, higher alcohol ester salts, alkylbenzene sulfonate salts, sulfosuccinic acid ester salts, higher alcohol phosphoric acid ester salts, aliphatic amine salts, 4 Nonionic surfactants such as cationic surfactants such as quaternary ammonium salts, ethylene oxide adducts of higher alcohols, ethylene oxide adducts of alkylphenols, polyhydric alcohol fatty acid esters, acetylene glycol and its ethylene oxide adducts And amphoteric surfactants such as amino acid type and betaine type, fluorine-based compounds, and silicon-based compounds. These may be used alone or in combination of two or more.

By incorporating a surfactant into the ink jet recording ink of the present invention and adjusting the liquid physical properties of the ink such as surface tension, the ink ejection stability is improved, the water resistance of the image is improved, and the printed ink bleeds. In addition, it is possible to provide an excellent effect in preventing color transfer. Further, two or more kinds of the above surfactants may be used in combination.
The ink composition used in the present invention preferably contains 0.05 to 50 g / L of surfactant, more preferably 0.05 to 30 g / L. When the content of the surfactant in the ink composition is in the range of 0.05 to 50 g / L, the discharge stability does not deteriorate, the occurrence of bleeding at the time of color mixing, the deterioration of printing quality such as the generation of whiskers does not occur, At the time of ejection, it is possible to suppress printing defects due to ink adhesion to the hard surface.

  The ink for inkjet recording of the present invention can be prepared by dissolving the dye in an aqueous medium, adding a specific amount of a surfactant, and dissolving and / or dispersing other additives as necessary. it can. The “aqueous medium” in the present invention means a mixture of water or a mixture of water and a small amount of a water-miscible organic solvent with additives such as a wetting agent, a stabilizer and a preservative added as necessary.

When preparing the ink liquid of the present invention, in the case of water-soluble ink, it is preferable to first dissolve in water. Thereafter, various solvents and additives are added, dissolved and mixed to obtain a uniform ink solution.
As the dissolution method at this time, various methods such as dissolution by stirring, dissolution by ultrasonic irradiation, and dissolution by shaking can be used. Of these, the stirring method is particularly preferably used. In the case of stirring, various methods such as fluidized stirring known in the art and stirring using shearing force using an inverted agitator or dissolver can be used. On the other hand, a stirring method using a shearing force with the bottom surface of the container, such as a magnetic stirrer, can also be preferably used.

  Regarding preparation methods of water-based inkjet inks, JP-A-5-148436, JP-A-5-295212, JP-A-7-97541, JP-A-7-82515, JP-A-7-118857, JP-A-2002-020657, and JP-A-2002-020657. Details are described in each publication of Japanese Patent Publication No. 2002-060663, and can also be used for preparing the ink for inkjet recording of the present invention.

The ink of the present invention may contain at least one water-soluble dye represented by the general formula (Y). Examples of the water-miscible organic solvent include the following. A water-miscible organic solvent suitable for the present invention can be selected from the following.
Alcohol (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, t-butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol), polyhydric alcohols (eg, ethylene glycol, diethylene glycol, thiol) Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, 1,3-butanediol, 1,5-pentanediol, 1, 2-hexanediol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetri Thiodiglycol), glycol derivatives (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol mono Butyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, pro Glycol monopropyl ether,

Ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethylene glycol monophenyl ether), amine (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, tetramethylpropylenediamine) and other polar solvents (eg, formamide, N, N-dimethylformamide, N, N- Dimethylacetamide, dimethylsulfoxide, sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone N- vinyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone, diacetone alcohol).
In addition, the said water miscible organic solvent may use 2 or more types together.

When the other dye used in combination with the present invention is an oil-soluble dye, it can be prepared by dissolving the oil-soluble dye in a high boiling point organic solvent and emulsifying and dispersing it in an aqueous medium.
The high-boiling organic solvent used has a boiling point of 150 ° C. or higher, preferably 170 ° C. or higher.
The high-boiling organic solvent can be used in an amount of 0.01 to 3 times, preferably 0.01 to 1.0 times the mass ratio of the oil-soluble dye.
These high boiling point organic solvents may be used alone or in a mixture of several kinds.
The high boiling point organic solvent is used in an amount of 0.01 to 3.0 times, preferably 0.01 to 1.0 times the mass ratio of the oil-soluble dye.

  In the present invention, the oil-soluble dye and the high boiling point organic solvent are emulsified and dispersed in an aqueous medium. In the emulsification dispersion, a low boiling organic solvent can be used depending on the case from the viewpoint of emulsification. The low boiling point organic solvent is an organic solvent having a boiling point of about 30 ° C. or higher and 150 ° C. or lower at normal pressure. For example, esters (eg ethyl acetate, butyl acetate, ethyl propionate, β-ethoxyethyl acetate, methyl cellosolve acetate), alcohols (eg isopropyl alcohol, n-butyl alcohol, secondary butyl alcohol), ketones (eg methyl isobutyl) Ketones, methyl ethyl ketone, cyclohexanone), amides (for example, dimethylformamide, N-methylpyrrolidone), ethers (for example, tetrahydrofuran, dioxane) and the like are preferably used, but are not limited thereto.

  The emulsification dispersion is used to disperse an oil phase in which a dye is dissolved in a mixed solvent of a high-boiling organic solvent and, optionally, a low-boiling organic solvent, in an aqueous phase mainly composed of water to form fine oil droplets in the oil phase. Done. At this time, additives such as a surfactant, a wetting agent, a dye stabilizer, an emulsion stabilizer, an antiseptic and an antifungal agent, which will be described later, are added to either or both of the aqueous phase and the oil phase as necessary. be able to. As an emulsification method, a method of adding an oil phase to an aqueous phase is common, but a so-called phase inversion emulsification method in which an aqueous phase is dropped into an oil phase can also be preferably used.

The pressure when emulsifying with the high-pressure emulsifying dispersion device is 50 MPa or more, preferably 60 MPa or more, more preferably 180 MPa or more.
For example, it is a particularly preferable method that two or more types of emulsifiers are used in combination by a method such as emulsification with a stirring emulsifier and then passing through a high-pressure homogenizer. Also preferred is a method of once emulsifying and dispersing with these emulsifiers, adding an additive such as a wetting agent or a surfactant, and then passing the high-pressure homogenizer again while filling the cartridge with ink.
When a low boiling point organic solvent is contained in addition to the high boiling point organic solvent, it is preferable to remove the low boiling point solvent from the viewpoint of the stability of the emulsion and safety and health. Various known methods can be used as the method for removing the low boiling point solvent depending on the type of the solvent. That is, an evaporation method, a vacuum evaporation method, an ultrafiltration method, and the like. This step of removing the low-boiling organic solvent is preferably performed as soon as possible immediately after emulsification.

  In the present invention, in addition to the above compounds, when used as an inkjet recording ink, a drying inhibitor for preventing clogging due to drying at the ink jetting port, a penetration accelerator for penetrating the ink with paper, Select additives such as UV absorbers, antioxidants, viscosity modifiers, surface tension modifiers, dispersants, dispersion stabilizers, antifungal agents, rust inhibitors, pH adjusters, antifoaming agents, chelating agents, etc. Can be used in an appropriate amount.

The drying inhibitor used in the present invention is preferably a water-soluble organic solvent having a vapor pressure lower than that of water.
Specific examples include ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, thiodiglycol, dithiodiglycol, 2-methyl-1,3-propanediol, 1,2,6-hexanetriol, acetylene glycol derivatives, glycerin. Polyhydric alcohols typified by trimethylolpropane, etc., lower alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monoethyl (or butyl) ether 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, heterocyclic rings such as N-ethylmorpholine, sulfolane, dimethyl sulfoxide, 3 Sulfur-containing compounds such as sulfolane, diacetone alcohol, polyfunctional compounds such as diethanolamine, and urea derivatives. Of these, polyhydric alcohols such as glycerin and diethylene glycol are more preferred. Moreover, said anti-drying agent may be used independently and may be used together 2 or more types. These drying inhibitors are preferably contained in the ink in an amount of 10 to 50% by mass.

  Examples of penetration enhancers used in the present invention include alcohols such as ethanol, isopropanol, butanol, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, and 1,2-hexanediol, sodium lauryl sulfate, sodium oleate, and nonionic surface activity. An agent or the like can also be used. If these are contained in the ink in an amount of 10 to 30% by mass, the effect is sufficient, and it is preferable to use them in a range of addition amounts that do not cause printing bleeding and paper loss (print through).

  Examples of the ultraviolet absorber used for improving the storability of the image in the present invention include JP-A Nos. 58-185677, 61-190537, JP-A-2-782, and JP-A-5-97075. Benzotriazole compounds described in JP-A-9-34057, etc., benzophenone compounds described in JP-A No. 46-2784, JP-A-5-194443, US Pat. No. 3,214,463, etc. -30492, 56-211141, cinnamic acid compounds described in JP-A-10-88106, JP-A-4-298503, 8-53427, 8-239368 Triazine compounds described in JP-A-10-182621, JP-A-8-501291, etc., Research Disclosure Over No. A compound described in No. 24239, a compound that emits fluorescence by absorbing ultraviolet rays typified by a stilbene series or a benzoxazole series, a so-called fluorescent whitening agent can also be used.

  As the antioxidant used for improving the storability of the image in the present invention, various organic and metal complex anti-fading agents can be used. Organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc. Complex, zinc complex and the like. More specifically, Research Disclosure No. No. 17643, No. VII, I to J, ibid. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of the representative compounds described in pages 127 to 137 of JP-A-62-215272 can be used.

  Antifungal agents used in the present invention include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one and its salts. Can be mentioned. These are preferably used in the ink in an amount of 0.02 to 5.00% by mass. Details of these are described in the “Anti-bacterial and fungal dictionary” (edited by the Japanese Society for Antibacterial and Fungal Dictionary). Examples of the rust inhibitor include acidic zinc sulfate, sodium thiosulfate, ammonium thioglycolate, diisopropyl ammonium nitrite, pentaerythritol nitrate, dicyclohexyl ammonium nitrite, and benzotriazole. These are preferably used in an amount of 0.02 to 5.00% by mass in the ink.

The pH adjuster used in the present invention can be suitably used in terms of pH adjustment, imparting dispersion stability, etc., and the pH of the ink at 25 ° C. is adjusted to 8-11. When the pH is less than 8, the solubility of the dye is lowered and the nozzle is easily clogged, and when it exceeds 11, the water resistance is deteriorated. As a pH adjuster, an organic base, an inorganic alkali, etc. are mentioned as a basic thing, An organic acid, an inorganic acid, etc. are mentioned as an acidic thing.
Examples of the organic base include triethanolamine, diethanolamine, N-methyldiethanolamine, and dimethylethanolamine. Examples of the inorganic alkali include alkali metal hydroxides (for example, sodium hydroxide, lithium hydroxide, and potassium hydroxide), carbonates (for example, sodium carbonate, sodium hydrogen carbonate, and the like), ammonium, and the like. Examples of the organic acid include acetic acid, propionic acid, trifluoroacetic acid, and alkylsulfonic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, and phosphoric acid.

  The surface tension of the ink used in the present invention is preferably 20 to 50 mN / m or less at 25 ° C., more preferably 20 to 40 mN / m or less. By setting this value, the ejection stability and the printing quality tend to be good, and it becomes easy to prevent printing defects due to the adhesion of ink to the peripheral portion of the nozzle during ejection.

  The viscosity of the ink used in the present invention is preferably 30 mPa · s or less. Furthermore, since it is more preferable to adjust to 20 mPa * s or less, a viscosity modifier may be used in order to adjust a viscosity. Examples of the viscosity modifier include water-soluble polymers such as celluloses and polyvinyl alcohol, and nonionic surfactants. More specifically, “Viscosity Adjustment Technology” (Technical Information Association, 1999), Chapter 9, and “Chemicals for Inkjet Printers (98 Supplement) —Material Development Trends and Prospects Survey” (CMC, 1997) 162- Page 174.

  Furthermore, in the present invention, a polymer fine particle dispersion may be used. Details thereof are described in JP-A-2002-264490. In the present invention, the above-mentioned cation, anion, and nonionic surfactants are used as a dispersant and a dispersion stabilizer, and fluorine-based, silicone-based compounds, chelating agents represented by EDTA, and the like are used as necessary. be able to.

  The ink of the present invention is a known recording material, i.e., plain paper, resin-coated paper, such as JP-A-8-169172, JP-A-8-27693, JP-A-2-276670, JP-A-7-276789, JP-A-9-323475, JP-A-62-238783, JP-A-10-153898, JP-A-10-217473, JP-A-10-235995, JP-A-10-337947, and JP-A-10-217597. 10-337947, etc., can be used to form an image on ink jet paper, film, electrophotographic co-paper, fabric, glass, metal, ceramics and the like.

The recording paper and recording film used for inkjet printing using the ink of the present invention will be described below. The support for recording paper and recording film consists of chemical pulp such as LBKP and NBKP, mechanical pulp such as GP, PGW, RMP, TMP, CTMP, CMP, CGP, and waste paper pulp such as DIP. Additives such as known pigments, binders, sizing agents, fixing agents, cationic agents, paper strength enhancers, etc. can be mixed, and those manufactured by various devices such as long net paper machines and circular net paper machines can be used. It is. In addition to these supports, either synthetic paper or plastic film sheet may be used, and the thickness of the support is preferably 10 to 250 μm and the basis weight is preferably 10 to 250 g / m ² . The support may be provided with an ink receiving layer and a backcoat layer as they are, or after a size press or anchor coat layer is provided with starch, polyvinyl alcohol or the like, an ink receiving layer and a backcoat layer may be provided. Further, the support may be flattened by a calendar device such as a machine calendar, a TG calendar, or a soft calendar. In the present invention, as the support, paper and plastic film laminated on both sides with polyolefin (eg, polyethylene, polystyrene, polyethylene terephthalate, polybutene and copolymers thereof) are more preferably used. It is preferable to add a white pigment (eg, titanium oxide, zinc oxide) or a coloring dye (eg, cobalt blue, ultramarine blue, neodymium oxide) to the polyolefin polyolefin.

  The ink receiving layer provided on the support contains a pigment and an aqueous binder. As the pigment, a white pigment is good, and as the white pigment, calcium carbonate, kaolin, talc, clay, diatomaceous earth, synthetic amorphous silica, aluminum silicate, magnesium silicate, calcium silicate, aluminum hydroxide, alumina, lithopone, zeolite, Examples thereof include inorganic white pigments such as barium sulfate, calcium sulfate, titanium dioxide, zinc sulfide, and zinc carbonate, and organic pigments such as styrene pigments, acrylic pigments, urea resins, and melamine resins. The white pigment contained in the ink receiving layer is preferably a porous inorganic pigment, and synthetic amorphous silica having a large pore area is particularly suitable. As the synthetic amorphous silica, either anhydrous silicic acid obtained by a dry production method (gas phase method) or hydrous silicic acid obtained by a wet production method can be used, but it is particularly desirable to use hydrous silicic acid. Two or more of these pigments may be used in combination.

  Specific examples of the recording paper containing the pigment in the image receiving layer include JP-A Nos. 10-81064, 10-119423, 10-157277, 10-217601, and 10-348409. No. 2001-138621, 2000-43401, 2000-2111235, 2000-309157, 2001-96897, 2001-138627, JP-A-11-91242, 8-2087, Those disclosed in Nos. 8-2090, 8-2091, 8-2093, 8-174992, 11-192777, and JP-A-2001-301314 can be used.

  Examples of the aqueous binder contained in the ink receiving layer include polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationized starch, casein, gelatin, carboxymethylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, polyalkylene oxide, and polyalkylene oxide derivatives. Water-dispersible polymers such as water-soluble polymers, styrene butadiene latexes, and acrylic emulsions. These aqueous binders can be used alone or in combination of two or more. In the present invention, among these, polyvinyl alcohol and silanol-modified polyvinyl alcohol are particularly preferable in terms of adhesion to the pigment and resistance to peeling of the ink receiving layer. The ink receiving layer can contain a mordant, a water resistance agent, a light resistance improver, an ozone resistance improver, a surfactant, and other additives in addition to the pigment and the aqueous binder.

  The mordant added to the ink receiving layer is preferably immobilized. For that purpose, a polymer mordant is preferably used. For the polymer mordant, JP-A-48-28325, 54-74430, 54-124726, 55-22766, 55-142339, 60-23850, 60-23835, 60-23852, 60-23853, 60-57836, 60-60643, 60-118834, 60-122940, 60-122941, 60-122942, 60- No. 235134, JP-A-1-161236, U.S. Pat.Nos. 2,484,430, 2,548,564, 3,148,061, 3,309,690, 4,115,124, 4,124,386, 4,193,800, 4,283,853, 4,282,305, It is described in each specification of the same No. 4450224. An image receiving material containing a polymer mordant described in JP-A-1-161236, pages 212 to 215 is particularly preferred. When the polymer mordant described in the publication is used, an image with excellent image quality is obtained and the light resistance of the image is improved.

  The water-proofing agent is effective for making the image water-resistant. As these water-proofing agents, cationic resins are particularly desirable. Examples of such a cationic resin include polyamide polyamine epichlorohydrin, polyethyleneimine, polyamine sulfone, dimethyldiallylammonium chloride polymer, and cationic polyacrylamide. The content of these cationic resins is preferably 1 to 15% by mass, particularly 3 to 10% by mass, based on the total solid content of the ink receiving layer.

  Examples of the light resistance improver and gas resistance improver include phenol compounds, hindered phenol compounds, thioether compounds, thiourea compounds, thiocyanate compounds, amine compounds, hindered amine compounds, TEMPO compounds, hydrazine compounds, hydrazide compounds, amidine compounds, Vinyl group-containing compounds, ester compounds, amide compounds, ether compounds, alcohol compounds, sulfinic acid compounds, saccharides, water-soluble reducing compounds, organic acids, inorganic acids, hydroxy group-containing organic acids, benzotriazole compounds, benzophenone compounds, triazine compounds , Heterocyclic compounds, water-soluble metal salts, organometallic compounds, metal complexes, and the like. Specific examples of these compounds include JP-A-10-182621, JP-A-2001-260519, JP-A-2000-260519, JP-B-4-34953, JP-B-4-34513, and JP-B-4-34512. , JP-A-11-170686, JP-A-60-67190, JP-A-7-276808, JP-A-2000-94829, JP-T 8-512258, JP-A-11-321090, etc. Is mentioned.

The surfactant functions as a coating aid, a peelability improver, a slippage improver or an antistatic agent. The surfactant is described in JP-A Nos. 62-173463 and 62-183457.
An organic fluoro compound may be used in place of the surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compound include a fluorine-based surfactant, an oily fluorine-based compound (eg, fluorine oil), and a solid fluorine compound resin (eg, tetrafluoroethylene resin). The organic fluoro compounds are described in JP-B-57-9053 (columns 8 to 17), JP-A-61-20994, and 62-135826.

  As the hardener, materials described in JP-A-1-161236, page 222, JP-A-9-263036, JP-A-10-119423, and JP-A-2001-310547 can be used.

  Examples of other additives added to the ink receiving layer include pigment dispersants, thickeners, antifoaming agents, dyes, fluorescent whitening agents, preservatives, pH adjusters, matting agents, and hardening agents. . The ink receiving layer may be one layer or two layers.

  The recording paper and the recording film may be provided with a backcoat layer, and examples of components that can be added to this layer include a white pigment, an aqueous binder, and other components. Examples of white pigments contained in the backcoat layer include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, and aluminum silicate. White inorganic pigments such as diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, Examples thereof include organic pigments such as styrene plastic pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin, and melamine resin.

  As the aqueous binder contained in the backcoat layer, styrene / maleate copolymer, styrene / acrylate copolymer, polyvinyl alcohol, silanol modified polyvinyl alcohol, starch, cationized starch, casein, gelatin, carboxymethylcellulose Water-soluble polymers such as hydroxyethyl cellulose and polyvinyl pyrrolidone, and water-dispersible polymers such as styrene butadiene latex and acrylic emulsion. Examples of other components contained in the backcoat layer include an antifoaming agent, an antifoaming agent, a dye, a fluorescent brightening agent, a preservative, and a water-proofing agent.

  Polymer latex may be added to the constituent layers (including the back layer) of the inkjet recording paper and recording film. The polymer latex is used for the purpose of improving film physical properties such as dimensional stabilization, curling prevention, adhesion prevention, and film cracking prevention. The polymer latex is described in JP-A Nos. 62-245258, 62-1316648, and 62-110066. When a polymer latex having a low glass transition temperature (40 ° C. or lower) is added to a layer containing a mordant, cracking and curling of the layer can be prevented. Also, curling can be prevented by adding a polymer latex having a high glass transition temperature to the back layer.

The present invention also relates to an ink jet recording method using the ink for ink jet recording according to the present invention.
The ink of the present invention is not limited to the ink jet recording system, and is a known system such as a charge control system that ejects ink using electrostatic attraction, a drop-on-demand system (pressure pulse system) that uses the vibration pressure of a piezo element. ), An acoustic ink jet method that converts an electrical signal into an acoustic beam, irradiates the ink and uses ink to eject the ink, and a thermal ink jet method that heats the ink to form bubbles and uses the generated pressure. Used.
Inkjet recording methods use a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving image quality using a plurality of inks having substantially the same hue and different concentrations, and colorless and transparent inks. The method is included.
A preferred combination of a recording material and a recording method is an inkjet recording in which an image receiving material having an image receiving layer containing white inorganic pigment particles on a support is ejected with ink droplets according to a recording signal, and an image is recorded on the image receiving material. Is the method.

  The ink for ink jet recording of the present invention can also be used for purposes other than ink jet recording. For example, it can be used for display image materials, image forming materials for interior decoration materials, and image forming materials for outdoor decoration materials.

  Display image materials include posters, wallpaper, small decorative items (such as figurines and dolls), commercial flyers, wrapping paper, wrapping materials, paper bags, plastic bags, packaging materials, signs, transportation (automobiles, buses, trains, etc.) ) Refers to various things such as images drawn and attached to the side, clothes with logos, and so on. When the dye of the present invention is used as a material for forming a display image, the image includes all patterns of dyes that can be recognized by humans, such as abstract designs, characters, and geometric patterns, in addition to images in a narrow sense.

  The interior decoration material refers to various items such as wallpaper, decorative accessories (such as figurines and dolls), lighting fixture members, furniture members, floor and ceiling design members. When the dye of the present invention is used as an image forming material, the image includes all patterns of dyes that can be recognized by humans such as abstract designs, characters, and geometric patterns in addition to images in a narrow sense.

  The outdoor decoration material refers to various materials such as wall materials, roofing materials, signboards, gardening materials, outdoor decoration accessories (such as figurines and dolls), and members of outdoor lighting equipment. When the dye of the present invention is used as an image forming material, the image includes not only images in a narrow sense but also all patterns of dyes that can be recognized by humans, such as abstract designs, characters, and geometric patterns.

  In the above applications, examples of media on which a pattern is formed include various materials such as paper, fiber, cloth (including non-woven fabric), plastic, metal, and ceramics. As the dyeing form, the dye can be fixed in the form of mordanting, printing, or a reactive dye having a reactive group introduced. Among these, it is preferable that the mordanting is performed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

(Synthesis example)
Hereinafter, although the synthesis method of the dye mixture of this invention is demonstrated in detail to an Example, this invention is not limited to these Examples at all.

The dye represented by the formula (Y-1) of the present invention can be derived from, for example, the following synthesis route.
In the following examples, λmax is the absorption maximum wavelength, and εmax is the molar extinction coefficient at the absorption maximum wavelength. Moreover, what is simply described as% represents mass%.

(Synthesis Example 1)
In 450 mL of DMF (N, N-dimethylformamide) and 24.75 g of 1,2-dichloroethane, compound (a) (2-amino-5-mercapto-1,3,4-thiadiazole (Wako Pure Chemical Industries ( Co., Ltd./Catalog No. 019-11125)) was added to 76.5 g, potassium carbonate 79.5 g was added, the temperature was raised to 70 ° C., and the mixture was stirred at the same temperature for 30 minutes. Subsequently, 375 mL of warm water at 80 ° C. was dropped into the reaction solution over 10 minutes and cooled to an internal temperature of 25 ° C. The precipitated crystals were separated by filtration, washed with 250 mL of ion exchange water and subsequently with 150 mL of methanol, and then dried at 70 ° C. overnight to obtain 65.1 g of compound (b).

(Synthesis Example 2)
Aminoisophthalic acid (manufactured by Wako Pure Chemical Industries, Ltd./catalog number 322-26175) (A) 181.2 g was suspended in 1000 ml of ion-exchanged water, 257 mL of concentrated hydrochloric acid was added, and the mixture was heated to 5 ° C. in an ice bath. Kept. Thereto was added 116 ml of an aqueous solution of 69.7 g of sodium nitrite (reaction liquid A). 1300 ml of an aqueous solution containing 378.1 g of sodium sulfite was stirred at an internal temperature of 25 ° C., and the reaction solution A was poured therein. After stirring in this state for 30 minutes, the internal temperature was heated to 30 ° C. and stirred for 60 minutes. Hydrochloric acid 500mL was added to this reaction liquid, and it heated up immediately to the internal temperature of 50 degreeC (reaction liquid B). After stirring for 90 minutes in this state, 125.2 g of pivaloyl acetonitrile (manufactured by Tokyo Chemical Industry Co., Ltd./catalog number P1112) and 100 mL of isopropanol were added to the reaction solution B, and the internal temperature was raised to 93 ° C. Stir for 240 minutes. After cooling to room temperature, the precipitated crystals (C) were filtered with suction, and the crystals were washed with 1500 mL of ion-exchanged water and then with 1000 mL of isopropanol and dried. Isolated yield 223.5 g. Yield 73.7%.

(Synthesis Example 3)
29.2 g of the compound (b) was added at room temperature to 100 mL of methanesulfonic acid, 120 mL of acetic acid, and 180 mL of propionic acid, the internal temperature was raised to 45 ° C. to obtain a homogeneous solution, and then the internal temperature was cooled to 0 ° C. Subsequently, a solution of 14.7 g of NaNO ₂ and 27 mL of ion-exchanged water was added dropwise to the homogeneous solution while maintaining the internal temperature of 0 to 10 ° C., and stirred for 15 minutes at an internal temperature of 5 ° C. to prepare a diazonium salt. The diazonium salt solution was added dropwise to a solution prepared in advance from 60.6 g of the coupler component (C) prepared in Synthesis Example 2, 600 mL of methanol, and 600 mL of ethylene glycol at a rate maintaining the internal temperature of 0 to 10 ° C. Subsequently, the mixture was stirred at an internal temperature of 25 ° C. for 30 minutes. The precipitated crystals were filtered and washed with 250 mL of methanol, and then the crude crystals were dispersed in 650 mL of water, then stirred for 30 minutes at an internal temperature of 80 ° C., cooled to room temperature, filtered, washed with 300 mL of water, and then washed at 60 ° C. Drying overnight gave 64.47 g of dye (D).

(Synthesis Example 4)
In a solution of 16.5 g of KOH (tablet) prepared in advance and 414.9 mL of ion-exchanged water, 46.1 g of the dye (D) prepared in Synthesis Example 3 was added and dissolved at an internal temperature of 20 to 30 ° C.
Subsequently, a solution of 40.0 g of potassium acetate and 200 mL of methanol was dropped into the dye aqueous solution at an internal temperature of 25 ° C., and the mixture was stirred at the same temperature for 10 minutes. Thereafter, 2488 mL of IPA (isopropanol) was dropped to form a salt, and after stirring for 30 minutes at the same temperature, filtered, washed with 500 mL of IPA, dried at 70 ° C. overnight, and 44 g of a water solution represented by the formula (Y-1) A crude crystal of a functional dye was obtained.

(Synthesis Example 5)
After dissolving 8.7 g of a water-soluble dye crude crystal represented by the formula (Y-1) in ion exchange water 78.3 mL at room temperature, the pH value of the aqueous solution is adjusted to 8.5 using 0.1 N hydrochloric acid. After filtering through a 0.2 μm membrane filter, 391.5 mL of IPA was dropped into the filtrate at an internal temperature of 25 ° C. The precipitated crystals were filtered, washed with 100 mL of IPA, and dried overnight at 80 ° C. to obtain 7.8 g of a fine crystal of a water-soluble dye represented by the formula (Y-1). {Λmax: 428 nm (H ₂ O), εmax: 4.20 × 10 ⁴ }

(Synthesis Example 6)
Except that KOH of Synthesis Example 4 was changed to NaOH and potassium acetate was changed to sodium acetate, the same operation as in Synthesis Example 4 and Synthesis Example 5 was performed, and 7.7 g of a water-soluble dye (Y-2: general formula (Y ) To obtain a fine crystal of M = Na ⁺ ).

(Synthesis Example 7)
Except that KOH of Synthesis Example 4 was changed to LiOH and potassium acetate was changed to lithium acetate, the same operation as in Synthesis Example 4 and Synthesis Example 5 was performed, and 7.4 g of a water-soluble dye (Y-3: general formula (Y ) To obtain a fine crystal of M = Li ⁺ ).

(Synthesis Example 8)
Except that KOH of Synthesis Example 4 was changed to NH ₄ OH and potassium acetate was changed to ammonium acetate, the same operation as in Synthesis Example 4 and Synthesis Example 5 was performed, and 7.3 g of a water-soluble dye (Y-4: general formula A fine crystal of (M = NH ₄ ⁺ ) in (Y) was obtained.

[Preparation of Ink Stock Solution] The water-soluble dye (Y-1), which is the coloring material 1 obtained in Synthesis Example 5, and 1 (M = K ⁺ ion) / 2 (M in the group A as the coloring material 2 = K ⁺ ion) / 3 (M = K ⁺ ion) / 8 (M = K ⁺ ion) = 1/3/1/2 (mass ratio) at a mass ratio shown in Table 3 below, exceeding 100 g of the mixture These were completely mixed and dissolved in 900 g of pure water while stirring at room temperature. Subsequently, insoluble matter was filtered using a membrane filter having an average pore size of 0.2 μm, and ink stock solution 1 was obtained.

  Ink stock solutions 2 to 6, 101 are the same as the preparation of ink stock solution 1 except that the color material 1, the color material 2, and the type of water used for the preparation are changed, and the presence or absence of purification of the dye is changed. And 102 were prepared, respectively.

<Examples 1 to 22, Comparative Examples 1 and 2>
[Preparation of ink liquid]
Using the ink stock solutions 1 to 6 and 101 to 102 obtained above, ultrapure water was added to the components described below to make 1000 g, and the mixture was stirred and dissolved for 1 hour while heating at 30 to 40 ° C. Then, it filtered under reduced pressure with the micro filter with an average hole diameter of 0.25 micrometer, and adjusted yellow ink liquid 1-22 and 101-102, respectively.
When the heavy metal ion concentrations of the yellow ink liquids 1 to 22 and 101 to 102 were measured by an atomic absorption method, ions shown in Tables 4 to 6 were detected. In addition, trace amounts of transition metal ions were detected, and the total amount of transition metal ions was as shown in Tables 4-6.

[Composition of ink liquid]

* Acetylene glycol surfactant Proxel XL-II (1,2-benzisothiazolin-3-one, manufactured by AVECIA)

(Image recording and evaluation)
The following evaluation was performed about the ink for inkjet of the above this invention (ink liquid 1-22) and the comparative example (ink liquid 101-102). The results are shown in Table 7.
In Table 7, “smudge”, “color transfer”, “hue”, “color density”, and “image storage stability” indicate that each inkjet ink is an inkjet printer (trade name: PIXUS iP8600; manufactured by Canon Inc.). ) And evaluated after recording an image on Canon photo glossy film HG201.

<Evaluation of image blur and color transfer>
The photo glossy paper on which the image was formed was dried at room temperature for 1 hour, then immersed in deionized water for 10 seconds, and naturally dried at room temperature, and bleeding was observed. The evaluation was made in three stages, with A indicating low bleeding, B indicating moderate bleeding, and C indicating high bleeding.
Further, the color shift was recorded by continuously collecting six images and accumulated in the stacking unit. After all the recordings were completed, the color shift on the back side of the recording paper that overlapped the recording surface of the recording paper was observed. The case where there was no color transfer was evaluated as ○, and the case where even one sheet had color transfer was evaluated as ×.

<Image quality evaluation (color tone)>
Each of the inks obtained above was mounted on an ink jet recording apparatus (trade name: PIXUS iP8600; manufactured by Canon) using thermal energy. The recording conditions were a temperature of 23 ° C., a relative humidity of 55%, a recording density of 2,400 dpi × 1,200 dpi, and a discharge amount of 2.5 pL. An image with a recording duty of 60% was formed on the same recording medium as described above, and the image was naturally dried for 24 hours at a temperature of 23 ° C. and a relative humidity of 55%. The hue angle of the image portion of the recorded matter thus obtained was measured using a spectrophotometer (Spectorolino; manufactured by Gretag Macbeth) to evaluate the color tone. The evaluation criteria for the color tone are as follows. The evaluation results are shown in Table 7. In the present invention, AA, A and B are acceptable levels and C is not acceptable according to the following evaluation criteria.
AA: Hue angle is 88 ° or more and 90 ° or less.
A: The hue angle is 85 ° or more and less than 88 °, or greater than 90 ° and 92 ° or less.
B: The hue angle is 83 ° or more and less than 85 °, or greater than 92 ° and 94 ° or less.
C: Hue angle is less than 83 ° or greater than 94 °.

<Evaluation of image storage stability>
For image storage stability, a yellow solid image print sample was prepared and evaluated as follows. (1) Light fastness is determined by measuring the image density Ci immediately after printing with a reflection densitometer (X-Rite 310TR) and then irradiating the image with xenon light (85,000 lux) for 10 days using a weather meter manufactured by Atlas. Then, the image density Cf was measured again, and the dye residual ratio (100 × Cf / Ci) was determined and evaluated. The afterimage rate of the dye is evaluated at three points of reflection density of 1, 1.5, and 2. A is the case where the dye residual rate is 70% or more at any concentration, and B is the case where the point is less than 70%. When the concentration was less than 70%, C was designated. (2) About heat fastness, the density before and after storing a sample for 10 days under conditions of 80 ° C. and 15% RH was measured with a reflection densitometer (X-Rite 310TR), and the dye residual ratio was determined and evaluated. . The afterimage rate of the dye is evaluated at three points of reflection density of 1, 1.5, and 2. A is the case where the dye residual rate is 90% or more at any concentration, and B is the case where the reflection point is less than 90%. The concentration of less than 90% was defined as C.

  The evaluation was made in three stages, with A being a dye residual ratio of 80% or more at any concentration, A being 1 or 2 points being less than 80% B, and C being less than 70% at all concentrations.

<Bronze phenomenon>
The presence or absence of bronze phenomenon was evaluated by visually observing the image immediately after recording for 24 hours and then visually observing it. The case where bronze gloss was not confirmed at all was rated as “◯”, the case where slight bronze gloss was confirmed as Δ, and the case where bronze gloss was clearly confirmed as “X”. In addition, when the bronze phenomenon occurs, it can be confirmed that the print density is lower than that without the bronze phenomenon.

  The results obtained above are shown in Table 7.

<Examples 23 to 29>
An ink composition was prepared in the same manner as the ink liquid 1 except that the types and amounts of the coloring material 1 and the coloring material 2 in the ink stock solution 1 were changed as shown in Table 8 below.
Further, the mass ratio of the content (% by mass) of the second color material to the content (% by mass) of the first color material in the ink composition (containing at least one compound selected from Group A Amount] / [content of compound of general formula (Y) or formula (Y-1)]) is shown in Table 8 as “Coloring material 2 / Coloring material 1”.
Table 9 shows the results of evaluating these ink compositions in the same manner as ink liquid 1.

From the results shown in Tables 7 and 9, when the ink composition of the present invention is used for inkjet recording, the ink permeability to the image receiving paper is improved and ink bleeding and color transfer are prevented as compared with the comparative example. Can do. It can also be seen that the metallic luster of the printed matter, the so-called bronze phenomenon, has been improved at a high level and is excellent in storage stability.
Even when the image receiving paper used in the present invention is changed to a PM photographic paper manufactured by EPSON or PR101 manufactured by Canon, the same effect as the above results can be seen.

Claims (12)

An ink composition containing at least a first color material and a second color material,
The first color material is a compound represented by the following general formula (Y), the second color material is at least one compound selected from the following group A, and the second color The content (mass%) of the material in the ink composition is 0.001 or more and 1.0 or less in mass ratio with respect to the content (mass%) of the first color material in the ink composition. An ink composition, wherein the content of transition metal ions in the ink is 0.0001 mmol / l to 0.1 mmol / l.
General formula (Y)

(In the general formula (Y), each M independently represents a hydrogen atom or a cation. When M represents a cation, each represents a Li ⁺ ion, a Na ⁺ ion, a K ⁺ ion, or an NH ₄ ⁺ ion.)

(In group A, M independently represents a hydrogen atom or a cation, and when M represents a cation, it represents a Li ⁺ ion, a Na ⁺ ion, a K ⁺ ion, or an NH ₄ ⁺ ion.)   The ink composition according to claim 1, wherein the compound selected from Group A is at least one selected from 1, 2, 3, and 8. The compound represented by the general formula (Y), wherein the main component of M is a K ⁺ ion, and in the compound selected from Group A, the main component of M is a K ⁺ ion. Ink composition. 4. The ink composition according to claim 1, wherein all M in the compound represented by the general formula (Y) and the compound selected from Group A are K ⁺ ions.   5. The ink composition according to claim 1, wherein the content of the first color material is 1% by mass or more and 15% by mass or less based on the total mass of the ink composition.   The content (mass%) of the second color material in the ink composition is 0.001 or more in terms of mass ratio with respect to the content (mass%) of the first color material in the ink composition. The ink composition according to claim 1, which is 0.2 or less.   The ink composition according to any one of claims 1 to 6, wherein the content of the second color material is 0.01% by mass or more and 1.1% by mass or less based on the total mass of the ink composition. .   2. The transition metal ion is at least one selected from ions of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, and Hg. The ink composition as described in any one of -7.   The ink composition according to claim 1, wherein a content of the transition metal ion is 0.01 mmol / l to 0.1 mmol / l.   The ink composition according to any one of claims 1 to 9, comprising 0.2 to 20% by mass of the dye.   An ink for ink jet recording using the ink composition according to any one of claims 1 to 10.   An ink jet recording method for recording an image on an image receiving material by ejecting ink droplets onto an image receiving material having an image receiving layer containing white inorganic pigment particles on a support in accordance with a recording signal, wherein the ink droplets are claim 1. An ink for ink-jet recording comprising the ink composition according to any one of 10 to 10.