JP2012149217A - Ink composition, inkjet recording ink, and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition excellent in storage stability, capable of obtaining thick print density when using a plain paper, suppressing bleeding or color staining and excellent in robustness of the obtained image.SOLUTION: The ink composition comprises an ink which contains a first coloring material represented by general formula (Y) and a second specific coloring material in an aqueous medium, and at least one water-miscible organic solvent having the solubility to the first coloring material at 25°C of ≤10 (g/100 g of the solvent). The content of the second coloring material to that of the first coloring material is ≥0.001 but ≤1.0 in a mass ratio. In the general formula (Y), Ms are each independently hydrogen or cation, and M when being cation, is Li, Na, Kor NHion, and further at least one M is Kion.

Description

  The present invention relates to an ink composition that is excellent in storage stability, has a sufficiently high printing density of an image to be obtained, and suppresses bleeding and color transfer, an ink for ink jet recording, and an ink jet recording method using the ink.

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 dyes used in these inks for ink jet recording have high solubility in solvents, high density recording, good hue, fastness to light, heat, air, water and chemicals. It is required to have excellent properties, good fixability with respect to the image receiving material, hardly bleed, excellent storability as ink, no toxicity, high purity, and availability at low cost. Has been. However, it is extremely difficult to search for pigments that meet these requirements at a high level.

Various dyes and pigments have already been proposed for inkjet and are actually used. However, the present condition is that the pigment | dye which still satisfies all the requirements has not been discovered yet. Conventionally well-known dyes and pigments having a color index (C.I.) number are difficult to achieve both hue and fastness required for ink jet recording ink.
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 Document 2 describes an ink composition containing two or more yellow dyes having different λmax as an ink composition excellent in color reproducibility, color density, light resistance, and ozone resistance.

Patent Document 3 discloses that a specific dye and a water-miscible organic solvent are used, and have high fastness to light, heat, and ozone gas, and have ejection stability even for ink that has been aged for a long time or under harsh conditions. High and excellent ink jet inks are described.
On the other hand, Patent Document 4 describes an ink in which adhesion resistance and ejection stability are improved in addition to fastness by using a specific organic solvent.
Further, Patent Document 5 discloses that an ink jet which is not easily precipitated or solidified even when left for a long period of time and has excellent intermittent ejection stability not only in a low temperature and low humidity environment but also in a high temperature and low humidity environment. Ink is described.
However, it has been demanded to further increase the printing density for plain paper that is not coated with inkjet recording. In addition, further improvement has been demanded for the prevention of bleeding and color migration.

JP 2004-83903 A JP 2005-264085 JP Japanese Patent No. 4424894 JP 2009-256599 JP 2009-293012 JP

  Therefore, the problems to be solved by the present invention are excellent in storage stability, printing density (optical density: OD) on plain paper is sufficiently high, bleeding and color transfer are suppressed, and fastness of the obtained image is further improved. The present invention also provides an excellent ink composition, an ink jet recording ink using the ink composition, and an ink jet recording method using the ink jet recording ink.

  The above problems have been solved by the following method. That is, according to the present invention, the following ink composition, ink jet recording ink and ink jet recording method are provided.

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

群Ａ中、Ｍはそれぞれ独立に水素原子又はカチオンを表し、Ｍがカチオンを表す場合はＬｉ^＋イオン、Ｎａ^＋イオン、Ｋ^＋イオン又は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種である上記〔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^＋イオンである上記〔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^＋イオンである上記〔１〕〜〔３〕のいずれか一項に記載のインク組成物。
〔５〕
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以下である上記〔１〕〜〔４〕のいずれか一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が、インク組成物全質量に対して、０．０１〜１．１質量％である上記〔１〕〜〔５〕のいずれか一項に記載のインク組成物。
〔７〕
前記一般式（Ｙ）で表される第１の色材の含有量が、インク組成物全質量に対して、０．１〜２０質量％である上記〔１〕〜〔６〕のいずれか一項に記載のインク組成物。
〔８〕
前記インクジェット記録用インク組成物中の水混和性有機溶剤の含有量が、インク組成物全質量に対して５〜５０質量％である上記〔１〕〜〔７〕のいずれか一項に記載のインク組成物。
〔９〕
前記水混和性有機溶剤が多価アルコール類を含む上記〔１〕〜〔８〕のいずれか一項に記載のインク組成物。
〔１０〕
前記水混和性有機溶剤が更にグリコール誘導体を含む混合溶剤である上記〔９〕に記載のインク組成物。
〔１１〕
前記多価アルコールとしてグリセリンを含む上記〔９〕又は〔１０〕に記載のインク組成物。
〔１２〕
上記〔１〕〜〔１１〕のいずれか一項に記載のインク組成物を含有するインクジェット記録用インク。
〔１３〕
上記〔１２〕に記載のインクジェット記録用インクを用いるインクジェット記録方法。
〔１４〕
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、インク滴が上記〔１２〕に記載のインクジェット記録用インクからなるインクジェット記録方法。 [1]
An ink composition containing at least a first color material, a second color material, and a water-miscible organic solvent,
The first colorant is a compound represented by the following general formula (Y),
The second colorant is at least one compound selected from the following group A;
The content (mass%) of the second color material in the ink composition is 0.001 or more and 1 in mass ratio with respect to the content (mass%) of the first color material in the ink composition. 0.0 or less,
An ink composition containing, as the water-miscible organic solvent, at least one water-miscible organic solvent having a solubility of the first coloring material at 25 ° C. of 10 (g / 100 g solvent) or less.
General formula (Y)

In general formula (Y), M represents a hydrogen atom or a cation each independently, and when M represents a cation, it 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 as described in the above.
[4]
The ink composition according to any one of [1] to [3], wherein M in the compound represented by the general formula (Y) and the compound selected from Group A are all K ⁺ ions.
[5]
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 [4], which is 0.2 or less.
[6]
The content of the second color material in the ink composition is 0.01 to 1.1% by mass with respect to the total mass of the ink composition according to any one of the above [1] to [5]. The ink composition as described.
[7]
Any one of the above [1] to [6], wherein the content of the first coloring material represented by the general formula (Y) is 0.1 to 20% by mass with respect to the total mass of the ink composition. Item 4. The ink composition according to item.
[8]
The content of the water-miscible organic solvent in the ink composition for ink jet recording is 5 to 50% by mass with respect to the total mass of the ink composition, according to any one of [1] to [7] above. Ink composition.
[9]
The ink composition according to any one of [1] to [8], wherein the water-miscible organic solvent contains a polyhydric alcohol.
[10]
The ink composition according to [9], wherein the water-miscible organic solvent is a mixed solvent further containing a glycol derivative.
[11]
The ink composition according to [9] or [10], wherein glycerin is included as the polyhydric alcohol.
[12]
Ink for inkjet recording containing the ink composition according to any one of [1] to [11] above.
[13]
The inkjet recording method using the ink for inkjet recording as described in said [12].
[14]
An ink jet recording method for recording an image on an image receiving material by ejecting ink droplets on 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 jet recording method comprising the ink for ink jet recording described in the above.

  According to the present invention, the ink composition is excellent in storage stability, has a sufficiently high printing density on plain paper, can suppress bleeding and color transfer, and is excellent in fastness of the resulting image; An ink jet recording ink and an ink jet recording method using the ink jet recording ink can be provided.

Hereinafter, the present invention will be described in detail.
In the following description, the compound represented by the general formula (Y) and the compound represented by the formula (Y-1), which are the first coloring material, are “a compound of the general formula (Y)”, and Sometimes abbreviated as “compound of formula (Y-1)”. Further, at least one compound selected from the group A, which is the second color material, may be abbreviated as “a compound of group A”.

The ink for inkjet recording of the present invention is an ink composition containing at least a first color material, a second color material, and a water-miscible organic solvent,
The first colorant is a compound represented by the following general formula (Y) (hereinafter, the compound represented by the general formula (Y) may be referred to as “azo dye”),
The second colorant is at least one compound selected from the following group A;
The content (mass%) of the second color material in the ink composition is 0.001 or more and 1 in mass ratio with respect to the content (mass%) of the first color material in the ink composition. 0.0 or less,
The water-miscible organic solvent contains at least one water-miscible organic solvent in which the solubility of the first coloring material at 25 ° C. is 10 (g / 100 g solvent) or less.
General formula (Y)

In general formula (Y), M represents a hydrogen atom or a cation each independently, and when M represents a cation, it 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.

  In the present invention, in particular, a compound represented by the following formula (Y-1) is used as the first color material, and compounds 1, 2, 3, 5, and 5 in the group A are used as the second color material. 6 or 8 is preferably used, in particular, 1, 2, 3, 6 or 8 is more preferably used, and 1, 2, 3 or 8 is more preferably used.

The ink contains a compound represented by the general formula (Y) as the first color material, and contains a specific amount of at least one compound selected from the group A as the second color material, Printing at a sufficient density even on plain paper by containing at least one water-miscible organic solvent in which the solubility of one color material is not more than a specific value (the first color material is difficult to dissolve) In addition, bleeding and color transfer can be suppressed.
This is because, by using a water-miscible organic solvent in which the compound (dye) represented by the general formula (Y) is difficult to dissolve, the paper fibers are relatively hydrophilic when the ink penetrates into the paper. It is estimated that a sufficient concentration can be obtained because the adsorption of the dye is further promoted and the dye is easily insolubilized on the fiber, so that the dye can be fixed on the paper surface. In addition, it is estimated that the solvent present around the dye makes it difficult for the dye to move, prevents bleeding and suppresses color transfer. On the other hand, if the dye is difficult to dissolve in the solvent, the dye may precipitate and storage stability may decrease. However, adding a second colorant suppresses dye precipitation and improves storage stability. It was issued.
Furthermore, it has been found that the above-described configuration unexpectedly improves the image fastness including the color tone and light resistance.

(First color material)
The first color material used in the ink composition of the present invention is a compound represented by the general formula (Y), which is an azo dye (yellow dye), typically a water-soluble dye. Below, the azo dye represented by general formula (Y) is demonstrated.
General formula (Y)

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

M 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 is preferably a Na ⁺ ion, K ⁺ ion or NH ₄ ⁺ ion, more preferably a Na ⁺ ion or K ⁺ ion, and most preferably a K ⁺ ion. In the dye represented by the general formula (Y), it is preferable that the counter cation is K ⁺ ion is the main component of M, and more preferably all M is K ⁺ ion. Here, the main component of the counter cation M means ions occupying 80% or more (preferably 90% or more) in the total counter cation M.
If the main component of the counter cation M of the ionic hydrophilic group of the compound represented by the general formula (Y) is K ⁺ ion, the solubility in the ink solution is increased, and the formation and precipitation of salt is suppressed and the ink is suppressed. This is because the storage stability of the solution can be greatly improved.

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. When it is a mixed salt, it is preferably 50 to 100%, more preferably 60 to 100%, and still more preferably 80, in terms of molar fraction, of M contained in the dye represented by formula (Y) contained in the ink. It is preferable that M of ˜100%, especially 90-100% of them is K ⁺ ion. As M other than K ⁺ ions, Na ⁺ ions and NH ₄ ⁺ ions are preferable, and Na ⁺ ions are more preferable.
A mixed salt of K ⁺ ions and Na ⁺ ions is preferable from the viewpoint of balancing paper permeability and ink liquid stability.

Moreover, it is also preferable that M of the dye represented by the general formula (Y) contained in the ink is not a mixed salt but 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 cationic species in an ionized state of ⁻ and K ⁺ , 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. When all of them are K ⁺ ions, the types of additives for controlling the physical properties of the ink liquid can be reduced, and the influence of the environment during ink storage can be reduced.
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.

  By using the dye, an ink having a high printing density can be obtained even for plain paper, and bleeding and color transfer of an image can be suppressed. Moreover, it can be set as the quality which has favorable hue and color density. Furthermore, since it is excellent in fastness to light, heat, air, water, chemicals, etc. as compared with general azo dyes, it contributes to the storage stability of ink and recorded images.

(Second color material)
[Group A]
The ink composition of the present invention exhibits blur and color transfer of a printed matter 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. From the viewpoint of suppressing and improving the storage stability (such as ink storage stability) of the ink composition, the printing density of the ink, and the image fastness of the printed material, the ink composition may contain a second color material. is necessary. In the present invention, at least one compound selected from the following group A is used as the second color material. Among the at least one compound selected from the group A below, the compound 1, 2, 3, 5, 6 or 8 in the group A is particularly preferable, 1, 2, 3, 6, or 8 is particularly preferable, 2, 3 or 8 is more preferred.

  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, and 8 as the second color material. After combining 1, 2, 3, and 8, 5 or 6 may be used in combination, or 5 and 6 may be used in combination.

  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 coloring materials, not only can the yellow ink composition have high coloring power and high printing density, but also an image with excellent light resistance can be provided, and in addition, ink supply It is possible to satisfactorily satisfy the route clogging prevention and storage stability. Hereinafter, these general formulas will be described.

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.

[Content of coloring material]
The ink composition of the present invention is a concentrated aqueous solution containing a colorant (a first color material, a second color material, and, if necessary, another color material (dye, pigment, etc.)) at a high concentration as an ink raw material. It can be. The concentration of the colorant in the concentrated aqueous solution is preferably 20% by mass or less, 15% by mass or less, and preferably 12% by mass or less from the viewpoint of dye stability with time and ease of handling (viscosity). The concentration is preferably 8% by mass or more from the viewpoint of improving the quality and suppressing the transportation cost.
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 (% by mass) of the first colorant [the compound of the general formula (Y), preferably the compound of the formula (Y-1)] in the ink composition is preferably 0. 0% with respect to the total amount of the ink composition. It is 1-20 mass%, More preferably, it is 0.5-15 mass%, More preferably, it is 1.0-10 mass%.
Further, 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 to 2.0% by mass, and preferably 0.005 to 1.5% by mass with respect to the total amount of the ink composition. More preferably, it is 0.01 to 1.1 mass%, It is still more preferable that it is 0.05 mass to 0.8 mass%.

  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 bleeding and color transfer of the printed matter is suppressed and the light resistance and color tone of the image are satisfied, but also the storage stability. The reliability of the ink using the ink composition, such as the property and the recording durability, can 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.
By configuring the mass ratio of the content of the second color material to be in the above range, the solubility / light resistance of the first color material and the solubility / light resistance of the second color material Images with a high level of lightfastness that far exceed the performance expected from the combination can be formed. 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.

  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.

  Further, the total content (mass%) of the first color material and the second color material in the ink composition is 1.00 mass% or more and 24.00 mass based on the total mass of the ink composition. % Or less, more preferably 2.00% by mass or more and 18.00% by mass or less, and particularly preferably 3.00% by mass or more and 12.00% by 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 24.00% by mass or less, precipitation of insoluble matter in the ink is caused. 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.

(Ink composition)
The ink composition of the present invention (also referred to as the ink of the present invention) comprises a dye (first color material) represented by the general formula (Y) and the second color material, for example, water miscibility. It is made to contain in the aqueous medium containing an organic solvent.
The ink composition of the present invention is preferably used as an ink for inkjet recording. That is, the present invention also relates to an ink jet recording ink containing the ink composition of the present invention.
The ink for ink jet recording of the present invention can be prepared by diluting a stock solution of ink for ink jet recording (the aforementioned concentrated aqueous solution) with water or the like. The components described below which may be contained in the ink composition of the present invention can be included in the same manner.

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.

In addition to the water-soluble azo dye represented by the general formula (Y), the ink composition of the present invention (preferably an ink for ink jet recording) may be used in combination with other dyes in order to adjust the color tone and balance the performance. May be. For the purpose of obtaining a full-color image, an ink containing another dye or 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. As a preferable thing,
C. 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, 247
C. I. Direct violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100, 101
C. 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, 163
C. 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, 291
C. 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. 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. Acid Violet 5, 34, 43, 47, 48, 90, 103, 126
C. 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, 227
C. 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, 172
C. I. Reactive Red 3, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40, 41, 43, 45, 49, 55
C. I. Reactive violet 1, 3, 4, 5, 6, 7, 8, 9, 16, 17, 22, 23, 24, 26, 27, 33, 34
C. I. Reactive Yellow 2, 3, 13, 14, 15, 17, 18, 23, 24, 25, 26, 27, 29, 35, 37, 41, 42
C. I. Reactive Blue 2, 3, 5, 8, 10, 13, 14, 15, 17, 18, 19, 21, 25, 26, 27, 28, 29, 38
C. I. Reactive Black 4, 5, 8, 14, 21, 23, 26, 31, 32, 34
C. I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36, 38, 39, 45, 46
C. I. Basic violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35, 37, 39, 40, 48
C. I. Basic yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 39, 40
C. I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 41, 45, 46, 47, 54, 57, 60, 62, 65, 66, 69, 71
C. I. Basic Black 8,
Etc.

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. Regarding the literature, the Color Index (Edited by The Society of Dyers and Colorists), “Revised New Handbook of Pigments” edited by the Japan Pigment Technology Association (published in 1989), “Latest Pigment Applied Technology” published by CMC (published in 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).

Next, the surfactant that can be contained in the ink composition 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. It is possible to give an excellent effect to prevention of the above. Further, two or more kinds of the above surfactants may be used in combination.
The ink composition used in the present invention improves printing stability such as improvement in ejection stability, prevention of bleeding at the time of color mixing and prevention of whiskers, and also prevents printing defects due to ink adhesion to the hard surface during ejection. From the viewpoint, the surfactant is preferably contained in an amount of 0.005 to 5 mass%, more preferably 0.005 to 3 mass%. When the content of the surfactant in the ink composition is in the range of 0.005 to 5% by mass, the discharge stability does not deteriorate, the occurrence of bleeding at the time of color mixing, the deterioration of print quality such as the generation of whiskers does not occur, At the time of ejection, it is possible to suppress printing defects due to adhesion of ink to the periphery of the nozzle.

  The composition ink 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. . 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 2002. Details are described in each publication of -060663, and can also be used to prepare the ink for inkjet recording of the present invention.

(Water-miscible organic solvent)
As the water-miscible organic solvent used in the present invention, one having a solubility at 25 ° C. of the dye represented by the general formula (Y) of 10 (g / 100 g solvent) or less is selected. Here, the solubility means the mass of a solute that can be dissolved at a certain temperature in 100 g of the solvent, and the unit is “g / 100 g solvent”.
The solubility of the dye represented by formula (Y) of the present invention varies somewhat depending on its structure, but the solubility of the ink of the present invention is 10 (g / 100 g solvent) or less depending on the dye type. It is necessary to select a water-miscible organic solvent appropriately.
The solubility of the dye of the present invention at 25 ° C. is more preferably 8 (g / 100 g solvent) or less, and still more preferably 5 (g / 100 g solvent) or less.
The content of the water-miscible organic solvent in the ink composition of the present invention is 1 to 60% by mass with respect to the total mass of the ink composition from the viewpoint of achieving both ink stability and ejection stability and drying properties. It is preferable that it is 5-50 mass%.

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.
Alcohols (monoalcohols such as methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, dodecanol, cyclohexanol, benzyl alcohol, and acetylene alcohols),
Polyhydric alcohols (eg, ethylene diols such as ethylene glycol, diethylene glycol, thiodiethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol; 2-methyl-1,3-propanediol, 2-ethyl-1,3 Propanediols such as propanediol and 3-methoxy-1,2-propanediol; butanediol such as 2-butene-1,4-diol, 1,3-butanediol and 2-methyl-1,4-butanediol 2-methyl-2,4-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 3-methyl-1,3-pentanediol, 2,4-diethyl-1,5-pentanediol Pentanediols such as 1,2-hexanediol, etc. Hexanediols such as 1,2,6-trimethyl-1,7-heptanediol and 2,4,6-triethyl-1,7-heptanediol; 3,6-dithia-1,8- Octanediols such as octanediol; other alkylene diols such as propylene glycol, dipropylene glycol, polypropylene glycol and butylene glycol; polyols such as glycerin, hexanetriol, thiodiglycol and trimethylolpropane)
Glycol derivatives (for example, 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 monobutyl ether, propylene glycol monomethyl ether, Propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monopropyl Pills ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether, ethylene glycol monophenyl ether),

Amines (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, tetramethylpropylenediamine), and ,
Other polar solvents (for example, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 3-methylsulfolane, 3-sulfolene, bis (2-hydroxyethyl) sulfone, 2-pyrrolidone N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone-5-carboxylic acid, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone, diacetone alcohol, 4-picoline).
Two or more water-miscible organic solvents may be used in combination. When two or more types of water-miscible organic solvents are used, at least one of the dyes represented by the general formula (Y) may have a solubility at 25 ° C. of 10 (g / 100 g solvent) or less. Although the solubility may exceed 10 (g / 100 g solvent), all of the water-miscible organic solvents used preferably have a solubility of 10 (g / 100 g solvent) or less.

  Water miscible organic solvents include glycerin, propylene glycol (PG), dipropylene glycol (DPG), ethylene glycol monobutyl ether (EGmBE), diethylene glycol monobutyl ether (DEGmBE), propylene glycol monomethyl ether (PGmME), propylene glycol monopropyl Ether (PGmPE) and the like are preferable.

The water-miscible organic solvent preferably contains a polyhydric alcohol, and more preferably contains glycerin. This is because glycerin is easily soluble in water, is excellent as a moisturizing agent, has almost no odor toxicity, and can be obtained at a low cost, while the solubility of the dye according to the present invention is low and the required characteristics can be easily controlled.
The water-miscible organic solvent is preferably a mixture of at least one of two or more containing alcohol and / or a derivative thereof (polyhydric alcohol or the like), and is a mixed solvent containing a glycol derivative. More preferred.
When the water-miscible organic solvent is a mixed solvent, the content of the polyhydric alcohol is preferably 40% by mass to 100% by mass, and 60% by mass to 100% by mass with respect to the total mass of the water-miscible organic solvent. %, More preferably 80% by mass to 100% by mass.
As these solvents, commercially available ones can be used, and they can be synthesized by a usual method.

  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 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, Nos. VII to I, J; 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 8 or more, the solubility of the dye is good and clogging of the nozzle can be prevented, and when it is 11 or less, the water resistance can be kept good. 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 No. 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 sheets 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, 4,2,387,305, 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 concretely, it is not limited to this.

The dye represented by the formula (Y-1) according to 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.

(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 (A) ((Wako Pure Chemical Industries, Ltd./Catalog No. 322-26175)) 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. To this reaction liquid, 500 mL of hydrochloric acid was added, and the temperature was immediately raised to an internal temperature of 50 ° C. (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 dropped into the homogeneous solution while maintaining the internal temperature of 0 to 10 ° C., and the mixture was 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 isopropanol was dropped to form a salt, and after stirring for 30 minutes at the same temperature, filtration, washing with 500 mL of isopropanol, drying at 70 ° C. overnight, 44 g of the water-soluble dye represented by the formula (Y-1) Of crude crystals were 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 filtration through a 0.2 μm membrane filter, 391.5 mL of IPA (isopropanol) was dropped into the filtrate at an internal temperature of 25 ° C. The precipitated crystals were filtered, washed with 100 mL of isopropanol, 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.

(Examples 1-7, Comparative Examples 1-3)
[Adjustment of ink liquid]
Using the water-soluble dye Y-1 (coloring material 1) obtained in Synthesis Example 5 and the dye of group A (coloring material 2), the ink liquids 1 to 7 of the present invention and comparative examples were used as follows. Ink liquids 101 to 103 were prepared.
First, after adding each component shown in Table 1 below to a total of 1000 g by adding ultrapure water, it 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 prepared the ink liquid.

DEG: Diethylene glycol
TEGmME: Triethylene glycol monomethyl ether
DEGmBE: Diethylene glycol monobutyl ether
DPG: Dipropylene glycol
PGmME: Propylene glycol monomethyl ether
TEGmBE: Triethylene glycol monobutyl ether
PG: Propylene glycol
TEG: Triethylene glycol
PROXEL XL2 (trade name): 1,2-benzisothiazolin-3-one, manufactured by AVECIA

  The solubility (25 ° C.) of the dye (Y-1) in each solvent is shown in Table 2 below.

(Image recording and evaluation)
The following evaluation was performed about the ink liquid of the above this invention (ink liquid 1-5) and the comparative example (ink liquid 101-103). The results are shown in Table 3.

<Evaluation of hue of image>
Each of the inks obtained above was mounted on an ink jet recording apparatus (trade name: PIXUS iP8600; manufactured by Canon Inc.) 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. Then, an image with a recording duty of 60% is formed on photographic paper (Photo Gloss Film HG201 manufactured by Canon Inc.) and plain paper (Fuji Xerox Co., Ltd.), and the image is 24 hours at a temperature of 23 ° C. and a relative humidity of 55%. Naturally dried. The hue angle of the image portion of the recorded matter thus obtained was measured using a spectrophotometer (Spectorolino; manufactured by Gretag Macbeth), and the image density was evaluated using the hue angle as an index. The evaluation criteria are as follows. In the present invention, according to the following evaluation criteria, AA, A, and B are set to a level where the print density is sufficient and allowable, and C is set to a level where the print density is low and cannot be allowed. The photographic paper is a recording medium having an ink image receiving layer containing white inorganic pigment particles on a support.
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 fine line blur (image blur)>
Each of the inks obtained above was mounted on an ink jet recording apparatus (trade name: PIXUS iP8600; manufactured by Canon Inc.) 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. A fine line pattern with a recording duty of 60% is formed on photographic paper (Photo Gloss Film HG201 manufactured by Canon Inc.) and stored for 3 days at a temperature of 40 ° C. and a relative humidity of 85%. Evaluation was made according to the following criteria. According to the following evaluation criteria, AA and A were acceptable levels, and B and C were unacceptable levels.
AA: No blurring A: Little blurring B: Medium blurring C: High blurring

<Evaluation of color transfer>
Each of the inks obtained above was mounted on an ink jet recording apparatus (trade name: PIXUS iP8600; manufactured by Canon Inc.) 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. Then, an image with a recording duty of 60% was formed on photographic paper (Photo Glossy Film HG201 manufactured by Canon Inc.). Six consecutive images were recorded and accumulated in the accumulating unit of the recording apparatus. After all recordings were completed, the color transfer on the back side of the recording paper that had 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 ×.

<Light resistance>
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 50% was formed on a recording medium (trade name: Canon Photographic Paper Glossy Pro [Platinum Grade] PT-101; manufactured by Canon), and the image was natural for 24 hours at a temperature of 23 ° C. and a relative humidity of 55%. Dried. The optical density of the image portion of the recorded matter thus obtained was measured (referred to as “optical density before test”). Further, this recorded matter was exposed for 72 hours at an irradiation intensity of 100 kilolux, a bath temperature of 24 ° C., and a relative humidity of 60% using a super xenon tester (trade name: SX-75; manufactured by Suga Test Instruments). Thereafter, the optical density of the image portion of the recorded matter was measured (referred to as “optical density after test”). The optical density was measured using a spectrophotometer (Spectorolino; manufactured by Gretag Macbeth) under the conditions of light source: D50 and field of view: 2 °. From the obtained values of the optical density before the test and the optical density after the test, the residual ratio of the optical density was calculated based on the following formula, and the light resistance was evaluated. The criteria for light resistance are as follows. In the present invention, AA and A are acceptable levels and B and C are unacceptable levels according to the following evaluation criteria.

AA: The residual ratio of optical density is 90% or more.
A: The residual ratio of the optical density is 80% or more and less than 90%.
B: The residual ratio of the optical density is 70% or more and less than 80%.
C: The residual ratio of optical density is less than 70%.

<Ink storage stability>
Each ink was filled in an ink cartridge for an ink jet recording apparatus (trade name: PIXUS iP8600; manufactured by Canon), and the ink supply port was closed so that the ink in the ink cartridge did not evaporate. This ink cartridge was put in a sealed container and stored in a thermostatic bath at a temperature of 60 ° C. for 3 months. Thereafter, the ink cartridge was taken out from the thermostat and attached to the head cartridge of the ink jet recording apparatus. Then, it was stored for 2 weeks at a temperature of 35 ° C. and a humidity of 10% with the discharge port of the head cartridge exposed. Thereafter, the head cartridge was mounted on the same ink jet recording apparatus as described above, and suction was performed a predetermined number of times, and the recoverability was confirmed to evaluate the storage stability of the ink. The suction means “print head cleaning” which is one of functions provided in the ink jet recording apparatus (trade name: PIXUS iP8600; manufactured by Canon Inc.). The evaluation criteria for storage stability are as follows. In the present invention, AA and A are acceptable levels and B and C are unacceptable levels according to the following evaluation criteria.
AA: All the discharge ports recovered to a state where they could be discharged without any problem by suctioning 4 times or less.
A: All the discharge ports recovered to a state where they could be discharged without problems after 5 suctions.
B: It recovered to the state which can discharge all the discharge ports without a problem by 6 times of attraction | suction.
C: There were discharge ports that could not be discharged even after 7 or more times of suction.

From the results shown in Table 3, when the ink composition of the present invention is used for inkjet recording, a sufficient printing density can be obtained for plain paper as compared with the comparative example, and bleeding and color transfer of the resulting image can be prevented. It can be seen that it is excellent in prevention and light resistance, and is excellent in storage stability of ink.
Further, from the results of the ink liquids 1, 6 and 7 of Examples 1, 6 and 7, and the ink liquids 102 and 103 of Comparative Examples 2 and 3, the ratio of Colorant 2 / Colorant 1 is 0.001 to 1.0. It can be seen that results excellent in image density, light resistance and storage stability can be obtained in the range of.
Even when the image-receiving paper used was changed to EPSON PM photographic paper or Canon PR-201, the same effect as the above results was observed.

(Examples 8 to 17)
As shown in Table 5 below, the color material 1 of the ink liquid 1 is changed from the water-soluble dye Y-1 to the water-soluble dyes Y-2 to Y-4 obtained in Synthesis Examples 6 to 8, and the color material 1 Ink liquids 8 to 14 were prepared in the same manner as ink liquid 1 except that the content of colorant 2 and the type and content of colorant 2 were changed. The solubility (25 ° C.) of Y-2 to Y-4 in the solvents (glycerin and DEGmBE) used in the ink liquids 8 to 14 is shown in Table 4 below. In addition, ink liquids 15 to 17 were prepared in the same manner as ink liquid 1 except that color material 2 of ink liquid 1 was changed to the type shown in Table 6 below.
Ink liquids 8 to 17 were evaluated in the same manner as in Example 1. The results are shown in Table 7 below.

As shown in Tables 3 and 7, it can be seen from the results of ink liquids 1 and 8 to 10 that K ⁺ ions are excellent as counter cations in coloring materials 1 and 2. Further, from the results of the ink liquids 1 and 15 to 17, it can be seen that 1, 2, 3, and 8 in the group A are excellent as the coloring material 2.
Even when the image-receiving paper used was changed to EPSON PM photographic paper or Canon PR-201, the same effect as the above results was observed.

Claims (14)

An ink composition containing at least a first color material, a second color material, and a water-miscible organic solvent,
The first colorant is a compound represented by the following general formula (Y),
The second colorant is at least one compound selected from the following group A;
The content (mass%) of the second color material in the ink composition is 0.001 or more and 1 in mass ratio with respect to the content (mass%) of the first color material in the ink composition. 0.0 or less,
An ink composition containing, as the water-miscible organic solvent, at least one water-miscible organic solvent having a solubility of the first coloring material at 25 ° C. of 10 (g / 100 g solvent) or less.
General formula (Y)

In general formula (Y), M represents a hydrogen atom or a cation each independently, and when M represents a cation, it 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. The ink composition according to any one of claims 1 to 3, wherein all M in the compound represented by the general formula (Y) and the compound selected from Group A are K ⁺ ions.   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 according to any one of claims 1 to 5, wherein the content of the second color material in the ink composition is 0.01 to 1.1 mass% with respect to the total mass of the ink composition. Composition.   7. The content of the first color material represented by the general formula (Y) is 0.1 to 20% by mass with respect to the total mass of the ink composition. Ink composition.   The ink composition according to any one of claims 1 to 7, wherein the content of the water-miscible organic solvent in the ink composition is 5 to 50% by mass with respect to the total mass of the ink composition.   The ink composition according to claim 1, wherein the water-miscible organic solvent contains a polyhydric alcohol.   The ink composition according to claim 9, wherein the water-miscible organic solvent is a mixed solvent further containing a glycol derivative.   The ink composition according to claim 9 or 10, comprising glycerin as the polyhydric alcohol.   Ink for inkjet recording containing the ink composition as described in any one of Claims 1-11.   An ink jet recording method using the ink for ink jet recording according to claim 12.   An ink jet recording method for recording an image on an image receiving material by ejecting ink droplets on 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 the ink drops. An ink jet recording method comprising the ink for ink jet recording described in 1.