JP2008163186A - Ink jet ink, ink set, ink jet recording method, and ink cartridge - Google Patents

Abstract

To provide an ink that does not cause color shift even when an image having a secondary color is recorded using an ink jet recording method.
An ink-jet ink comprising at least a compound of formula (1) as a colorant, wherein the compound of formula (1) has a solubilizing group number / molecular weight value of 2.0 × 10 ⁻³ or more, The ink contains 10% by mass or more of one or more water-soluble organic solvents having an evaporation rate of 70% or more, and the evaporation rate in all the water-soluble organic solvents in the ink is 70%. An ink-jet ink, wherein the proportion of the water-soluble organic solvent is 50% by mass or more.
[Selection figure] None

Description

  In the present invention, even when a secondary color is formed with another ink, an ink for inkjet (hereinafter, simply referred to as “ink” in some cases) has a small difference between the color tone predicted in the image design and the color tone of the actual recorded matter. The present invention relates to an ink set using the ink, a recording method, and an ink cartridge.

  The ink jet recording method is a recording method in which ink droplets are applied on a recording medium such as plain paper and glossy media to form an image, and it is rapidly spreading due to its low price and improved recording speed. Yes. Further, in addition to the progress of high quality image recording, with the rapid spread of digital cameras, it has become widespread as a method for outputting photographic images comparable to silver halide photographs. In recent years, higher image quality has been promoted, such as the miniaturization of ink droplets and the improvement of the color gamut accompanying the introduction of multicolor ink.

  On the other hand, as a problem of the ink jet recording system when compared with a silver salt photograph, there is an image storability of the obtained recorded matter. The recorded matter obtained by the ink jet recording method generally has lower image storage stability than silver salt photographs. In addition, when the recorded material is exposed to light, humidity, heat, environmental gases present in the air for a long time, the color material on the recorded material is deteriorated, and the color tone or fading of the image is likely to occur. There is. Therefore, many technical improvements have been made to improve the image storage stability.

  For example, an ink having improved ink fastness by using an anthrapyridone color material having a specific structure as the color material of the ink is disclosed (see Patent Documents 1 and 2). Images formed with these inks have very good fastness properties.

  When a secondary color or a secondary color is recorded by the ink jet recording method, usually, a plurality of inks are overlapped and recorded. For example, when a red image is recorded by an inkjet recording apparatus having cyan ink, magenta ink, and yellow ink, the magenta ink and the yellow ink are recorded in an overlapping manner. When recording a green image, the yellow ink and the cyan ink are recorded in an overlapping manner. Further, when recording a blue image, magenta ink and cyan ink are overlaid and recorded. When a gray image is recorded, cyan ink, magenta ink, and yellow ink are recorded in an overlapping manner.

Conventionally, when recording a plurality of these inks in an overlapping manner, an image having a secondary color is predicted by predicting the color tone of the secondary color from the value of L ^* a ^* b ^* determined by the CIE (International Lighting Commission) for each ink single color. On the other hand, it is designed to record which ink is recorded at which ratio. When the color tone of the recorded matter recorded in this way is compared with the color tone predicted in the above design (hereinafter sometimes referred to as “predicted color tone”), it may be slightly different. However, even if it is slightly different, it is difficult to discriminate visually, and until now, there has been no problem with slight differences between the color tone of the recorded matter and the predicted color tone.
JP 2002-332419 A JP 2003-192930 A

  However, as a result of diligent investigations by the present inventors, depending on the combination of the coloring material and water-soluble organic solvent used in the ink, a phenomenon may occur in which a significant difference occurs between the predicted color tone and the color tone of the recorded matter. I discovered that there is. Of course, this significant difference can be discerned visually. In the present invention, a phenomenon in which a significant difference between the predicted color tone and the color tone of the recorded matter occurs is called “color shift”.

  Further, as a result of investigations by the present inventors, an image formed by recording with another ink superimposed on an image formed using only one ink, even if no color shift occurs. It has also been found that color shifting may occur. Further, when the cause of the color shift is further examined, it has been found that it often occurs with an anthrapyridone compound having a specific solubilizing group number / molecular weight value.

  In order to avoid color shift, the anthrapyridone compound may not be used. However, anthrapyridone compounds are compounds that have both the color and fastness properties, and in order to achieve the high fastness of recorded materials in today's demands for high fastness of recorded materials. However, the use of the compound cannot be avoided. In addition to the ink containing the anthrapyridone compound alone as a color material, the use of the compound such as so-called toned gray ink and toned black ink using other compounds in addition to the compound as a color material is extremely high. Wide. As described above, the anthrapyridone compound is a compound having both color tone and fastness, and has a wide range of uses. Therefore, even when the anthrapyridone compound is used, there is a problem of how to use it without causing color shift.

  Accordingly, an object of the present invention is to provide an ink that does not cause color shift even when an image having a secondary color is recorded using an ink jet recording method, an ink set using the ink, and an ink cartridge. is there.

  As a result of investigations by the present inventors, even when recording is performed with another ink using an ink containing the anthrapyridone-based compound, the above problem is overcome by recording with a specific ink composition. , Succeeded in preventing color shift.

That is, the present invention is an ink-jet ink containing at least a compound of the following formula (1) as a colorant, wherein the compound of the following formula (1) has a solubilizing group number / molecular weight value of 2.0 × 10 ^−3. The ink contains one or more water-soluble organic solvents having an evaporation rate of 70% or more in the ink in an amount of 10% by mass or more, and is evaporated in all the water-soluble organic solvents in the ink. Provided is an inkjet ink, an ink set using the ink, an inkjet recording method, and an ink cartridge, wherein the proportion of a water-soluble organic solvent having a rate of 70% or more is 50% by mass or more.

（上記式（１）中、Ｒ¹は、置換若しくは非置換アルキル基、置換若しくは非置換アルコキシ基、又は置換若しくは非置換アリール基を表す。Ｒ²は、水素原子、アルキル基、ヒドロキシアルキル基、シクロヘキシル基、モノ若しくはジアルキルアミノアルキル基、又はシアノアルキル基を表す。Ｒ³は、水素原子、置換若しくは非置換アルコキシ基、又は置換若しくは非置換フェノキシ基を表す。Ｒ⁴は、水素原子、置換若しくは非置換アルキル基、又は置換若しくは非置換アリール基を表す。）

(In the above formula (1), R ¹ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted aryl group. R ² represents a hydrogen atom, an alkyl group, a hydroxyalkyl group, Represents a cyclohexyl group, a mono- or dialkylaminoalkyl group, or a cyanoalkyl group, R ³ represents a hydrogen atom, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted phenoxy group, and R ⁴ represents a hydrogen atom, substituted or Represents an unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

  An effect of the present invention is to provide an ink that does not cause color shift even when an image having a secondary color is recorded, an ink set using the same, an ink jet recording method, and an ink cartridge.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.
As described above, the present inventors have found that the color transfer mainly occurs because the ink contains an anthrapyridone compound having a specific solubilizing group number / molecular weight value at a specific content. I found out. As a result of investigations by the present inventors, it has been found that the occurrence of discoloration can be suppressed by using an ink containing a compound of the following formula (1) and further having a specific solvent composition.

（上記式（１）中、Ｒ¹は、置換若しくは非置換アルキル基、置換若しくは非置換アルコキシ基、又は置換若しくは非置換アリール基を表す。Ｒ²は、水素原子、アルキル基、ヒドロキシアルキル基、シクロヘキシル基、モノ若しくはジアルキルアミノアルキル基、又はシアノアルキル基を表す。Ｒ³は、水素原子、置換若しくは非置換アルコキシ基、又は置換若しくは非置換フェノキシ基を表す。Ｒ⁴は、水素原子、置換若しくは非置換アルキル基、又は置換若しくは非置換アリール基を表す。）

(In the above formula (1), R ¹ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted aryl group. R ² represents a hydrogen atom, an alkyl group, a hydroxyalkyl group, Represents a cyclohexyl group, a mono- or dialkylaminoalkyl group, or a cyanoalkyl group, R ³ represents a hydrogen atom, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted phenoxy group, and R ⁴ represents a hydrogen atom, substituted or Represents an unsubstituted alkyl group or a substituted or unsubstituted aryl group.)

  Specific exemplary compounds of the compound represented by the formula (1) that mainly characterize the present invention and the value of the number of solubilizing groups / molecular weight are listed below, but the present invention is not limited to these exemplary compounds. . In addition, exemplary compounds are shown in the form of ions.

  In addition, the compound of the said Formula (1) can be contained in 1 type or in combination of 2 or more types in an ink. As will be described in detail later, the color shift tends to occur when the content of the color material in the ink exceeds the amount of the color material that can be adsorbed by the ink receiving layer. Specifically, when the content (% by mass) of the compound of the formula (1) in the ink is 1% by mass or more based on the total mass of the ink, color transfer tends to occur. However, the content of the compound of the formula (1) is preferably 1% by mass or more in order to sufficiently obtain the characteristics of the anthrapyridone compound that achieve both the color tone and fastness. In addition, in order to adjust the color tone of the ink when a toning ink using another compound in addition to the compound of the formula (1) as a coloring material is used, the content of the compound of the formula (1) is 1% by mass. The above is preferable. In addition, the upper limit of the content (% by mass) of the compound of formula (1) in the ink is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the ink.

  The reason why the present inventor paid attention to the value of the solubilizing group number / molecular weight of the compound of the formula (1) is as follows. The inventors of the present invention have speculated that the difference in the amount of ink containing a color material adsorbed to a recording medium having an ink receiving layer is caused by color transfer. Moreover, it is because it was estimated that the difference in the ink adsorption amount was caused by the value of the solubilizing group number / molecular weight of the color material. Here, the solubilizing group is a functional group that contributes to the dissolution or dispersion of a coloring material in water, such as a phosphoric acid group, a carboxyl group, and a sulfonic acid group. In the present invention, the molecular weight when calculating the value of the number of solubilizing groups / molecular weight in the compound of formula (1) is the molecular weight in the state of ions in which the solubilizing group in the compound of formula (1) is dissociated. That is.

If the value of the number of solubilizing groups / molecular weight is less than 2.0 × 10 ⁻³ , the ratio of the solubilizing group to the molecular weight is too low, and the compound of the formula (1) may be precipitated in the ink. In addition, even if the ink cartridge is dissolved, if the ink cartridge containing the ink is attached to the ink jet recording apparatus, the fixing property may be lowered, or the recording performance may be reduced when recording is performed again after a short pause. A decrease may occur. Therefore, in order to obtain the effect of the present invention, the value of the number of solubilizing groups / molecular weight of the compound of the formula (1) must be 2.0 × 10 ⁻³ or more.

  The present inventors paid attention to the solubility of the compound of the formula (1) in a water-soluble organic solvent as a solution when color shift of the recorded matter occurs. The reason for paying attention to the solubility is as follows. When an ink containing a compound of formula (1) and a water-soluble organic solvent (good solvent) that easily dissolves the compound of formula (1) is applied to a recording medium having an ink receiving layer, the ink receiving layer is adsorbed. The color material that could not be removed is dissolved or dispersed in the water-soluble organic solvent. Furthermore, the color material may move in the ink receiving layer by an ink different from the ink applied to the recording medium before and after the ink. As a result, it is assumed that color shift will occur.

  Therefore, the present inventors have solved the above-mentioned problem by including a water-soluble organic solvent (poor solvent) that hardly dissolves the compound of the formula (1) in the ink containing the compound of the formula (1). I thought it was possible. That is, when an ink containing the compound of the formula (1) and a poor solvent is applied to a recording medium having an ink receiving layer, the color material that the ink receiving layer has not been absorbed can contain the poor solvent. It was considered that the solid-liquid separation was promptly performed, and as a result, the color shift could be suppressed.

  However, in actuality, even if a poor solvent is contained in the ink containing the compound of the formula (1), the color transfer cannot be suppressed. The reason for this is that even if it is a poor solvent for the compound of the formula (1), the compound of the formula (1) can be dissolved if it is a trace amount. At this time, by applying an ink different from the ink, the compound of the formula (1) in a state dissolved in a poor solvent moves in the ink receiving layer, so that it is considered that color transfer occurs.

Therefore, the present inventors have studied a water-soluble organic solvent capable of suppressing color transfer, and focused on the evaporation rate of the water-soluble organic solvent contained in the ink having the compound of the formula (1). Here, the evaporation rate in the present invention means that 5 g of a water-soluble organic solvent is put in a petri dish having an outer diameter of 31 mm and a height of 15 mm and stored for 72 hours in an environment at a temperature of 60 ° C. Thereafter, the mass of the water-soluble organic solvent present in the petri dish (the mass of the water-soluble organic solvent after storage) is measured. At this time, the evaporation rate is calculated from the following formula based on the value of “mass of water-soluble organic solvent after storage” and the mass of water-soluble organic solvent charged (mass of water-soluble organic solvent before storage). Is a value obtained by calculating the rate of change in mass of the water-soluble organic solvent based on

  When a water-soluble organic solvent having a low evaporation rate is contained in the ink, or before and after the ink containing the compound of the formula (1) is applied, the ink containing the water-soluble organic solvent having a low evaporation rate is applied. Assuming that In this case, the color material that could not be adsorbed by the ink receiving layer stays in the ink receiving layer in a state where the color material is dissolved or dispersed in the water-soluble organic solvent having a low evaporation rate. Color material moves. It is speculated that such a phenomenon is the cause of color shift.

  In the present invention, the reason why the color shift can be suppressed when the evaporation rate of the water-soluble organic solvent calculated as described above is 70% or more is not clear. I guess so. When the evaporation rate of the water-soluble organic solvent is 70% or more, after the ink is applied to the recording medium, the water-soluble organic solvent quickly evaporates, and the coloring material that cannot be adsorbed to the ink receiving layer is also quickly fixed. Liquid separation occurs and does not move further in the ink receiving layer. For these reasons, it is estimated that color shift can be suppressed. On the other hand, when the evaporation rate of the water-soluble organic solvent is less than 70%, after the ink is applied to the ink receiving layer of the recording medium, the water-soluble organic solvent remains in the ink receiving layer. As a result, it is presumed that the color material that could not be adsorbed by the ink receiving layer can move in the ink receiving layer, so that color transfer cannot be suppressed.

  In the ink of the present invention, the water-soluble organic solvent having an evaporation rate of 70% or more needs to be present in the ink by 10% by mass or more. If the content of the water-soluble organic solvent having an evaporation rate of 70% or more is less than 10% by mass, the amount of the water-soluble organic solvent may be too small to prevent color shift. Furthermore, the content of the water-soluble organic solvent is preferably 10% by mass or more and 30% by mass or less in the ink. If the water-soluble organic solvent exceeds 30% by mass in the ink, the ink is discharged from the recording head when the ink cartridge filled with the ink is mounted on the ink jet recording apparatus for a long period of time. May stick. For this reason, there is a case where the discharge property is lowered, which is not preferable.

  In the ink of the present invention, the proportion of the water-soluble organic solvent having the evaporation rate of 70% or more in all the water-soluble organic solvents in the ink needs to be 50% by mass or more. is there. When the ratio of the water-soluble organic solvent having an evaporation rate of 70% or more in all the water-soluble organic solvents in the ink is less than 50% by mass, the water-soluble organic solvent remains in the ink receiving layer. As a result, the color material that could not be adsorbed by the ink-receiving layer can move in the ink-receiving layer, and thus color shifting may not be suppressed. Furthermore, the proportion of the water-soluble organic solvent having an evaporation rate of 70% or more in all the water-soluble organic solvents in the ink is preferably 50% by mass or more and 80% by mass or less. When the ratio exceeds 80% by mass, the ink may be fixed at the discharge port of the recording head when the ink cartridge filled with the ink is mounted on the ink jet recording apparatus and left for a long period of time. For this reason, there is a case where the discharge property is lowered, which is not preferable.

  Specifically, preferred embodiments of the present invention are as follows. A water-soluble organic solvent containing one or more water-soluble organic solvents having an evaporation rate of 70% or more in the ink and having an evaporation rate of 70% or more in all the water-soluble organic solvents in the ink. This ink is used together with an ink in which the proportion of the solvent is 50% by mass or more.

  Here, in the present invention, the ink used together with the ink of the present invention (hereinafter sometimes referred to as “combined ink”) refers to the ink of the present invention when a certain recorded matter is recorded using an ink jet recording apparatus. Ink applied before and after being applied to a recording medium. This combined ink is filled in an ink cartridge different from the ink cartridge containing the ink of the present invention. The ink cartridge containing the ink of the present invention and the ink cartridge containing the ink of the present invention and the combined ink may be either adjacent to each other or separated from each other when mounted on the ink jet recording apparatus. When a color image is recorded using an ink jet recording apparatus, the ink that is normally used is mostly a plurality of inks.

  Even using only the ink of the present invention, it is possible to suppress color shift to some extent. However, in order to more effectively suppress the color shift, it is preferable that both the ink of the present invention and the combination ink have the following configuration. That is, the ink used in combination with the ink of the present invention contains 10% by mass or more of one or more water-soluble organic solvents having an evaporation rate of 70% or more, and the evaporation rate in all the water-soluble organic solvents is 70%. The proportion of the water-soluble organic solvent is more preferably 50% by mass or more. The reason why the water-soluble organic solvent contained in the combined ink preferably has an evaporation rate of 70% or more is not clear. However, the present inventors presume the reason as follows.

  When the evaporation rate of the water-soluble organic solvent contained in the combined ink is less than 70%, the solid-liquid separation of the color material contained in the ink of the present invention in the recording medium having the ink receiving layer is hindered. This is not preferred because of the possibility. On the contrary, if the evaporation rate of the water-soluble organic solvent in the combined ink is 70% or more, the water-soluble organic solvent quickly evaporates in the recording medium. And since it does not inhibit the solid-liquid separation in the recording medium of the color material contained in the ink of the present invention, it is considered that the color transfer can be more effectively suppressed.

  In the combined ink, the water-soluble organic solvent having an evaporation rate of 70% or more is preferably present in an amount of 10% by mass or more. If the content of the water-soluble organic solvent having an evaporation rate of 70% or more is less than 10% by mass, it is difficult to suppress color transfer, which is not preferable. Further, the content of the water-soluble organic solvent in the combined ink is preferably 10% by mass or more and less than 30% by mass. If the water-soluble organic solvent is present in the combined ink in an amount exceeding 30% by mass, the fixing property of the combined ink may be deteriorated. In addition, when an ink jet recording apparatus equipped with an ink cartridge filled with the combined ink is left for a long period of time, the combined ink may be fixed at the discharge port of the recording head. As a result, the discharge balance between the ink of the present invention and the combined ink may be lost, and the color balance of the recorded matter may be lost.

  In the combined ink, the proportion of the water-soluble organic solvent having an evaporation rate of 70% or more in all the water-soluble organic solvents in the combined ink is preferably 50% by mass or more. Even when the proportion of the water-soluble organic solvent having an evaporation rate of 70% or more in all the water-soluble organic solvents in the combined ink is less than 50% by mass, the color transfer of the ink of the present invention is not deteriorated. it is conceivable that. However, if the ratio is less than 50% by mass, the coloring material contained in the ink of the present invention can be solidified in the recording medium even when a water-soluble organic solvent having an evaporation rate of 70% or more is used for the combined ink. In some cases, liquid separation is hindered, and it is difficult to further suppress color shift. Furthermore, the proportion of the water-soluble organic solvent having an evaporation rate of 70% or more in all the water-soluble organic solvents in the combined ink is more preferably 50% by mass or more and 80% by mass or less. When the proportion of the water-soluble organic solvent in the combined ink exceeds 80% by mass, the fixing property of the combined ink may deteriorate. Further, when an ink jet recording apparatus equipped with an ink cartridge filled with the combined ink is left in the ink jet recording apparatus for a long period of time, the combined ink may be fixed at the discharge port of the recording head. As a result, the discharge balance between the ink of the present invention and the combined ink may be lost, and the color balance of the recorded matter may be lost.

For the verification of the color material used in the present invention, the following verification methods (1) to (3) using high performance liquid chromatography can be applied.
(1) Peak retention time (2) Maximum absorption wavelength at peak of (1) (3) Mass spectrum M / Z at peak of (1) (posi, nega)

The analysis conditions of the above high performance liquid chromatography (1) and (2) are as follows.
The ink solution diluted with pure water about 1,000 times is analyzed by high performance liquid chromatography under the following conditions, and the peak retention time and the maximum absorption wavelength of the peak are measured.

・流速：０．２ｍｌ／ｍｉｎ
・カラム温度：４０℃
・ＰＤＡ：２００ｎｍ〜７００ｎｍ Column: Symmetry C18 2.1mm x 150mm
Gradient conditions for each mobile phase

・ Flow rate: 0.2 ml / min
-Column temperature: 40 ° C
PDA: 200 nm to 700 nm

The analysis conditions of the mass spectrum of (3) above are as follows.
With respect to the obtained peak, a mass spectrum is measured under the following conditions, and the most strongly detected M / Z is measured for each of posi and negative.
・ Ionization method ・ ESI
Capillary voltage: 3.5 kV
Desolvent gas: 300 ° C
Ion source temperature: 120 ° C
Detector posi: 40V 200-1500amu / 0.9sec
nega: 40V 200-1500amu / 0.9sec

For example, the retention time, maximum absorption wavelength, M / Z (posi), and M / Z (negative) values for the exemplified compound 1 are shown in Table 2 below.

Further, as other color materials used together with the compound of the formula (1) in the gray ink, the following color materials are preferable.
(Yellow color material)
C. I. Direct yellow: 8, 11, 12, 27, 28, 33, 39, 44, 50, 58, 85, 86, 87, 88, 89, 98, 100, 110, 132, 173, etc.
C. I. Acid Yellow: 1, 3, 7, 11, 17, 23, 25, 29, 36, 38, 40, 42, 44, 76, 98, 99, etc.
C. I. Pigment Yellow: 1, 2, 3, 12, 13, 14, 15, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 114, 128, 138, 180, and the like.

（上記式（２）中、ｍはそれぞれ独立に１又は２を表す。Ｍ₁はそれぞれ独立に水素原子、アルカリ金属、アルカリ土類金属、有機アミンのカチオン、又はアンモニウムイオンを表す。） Moreover, the following color materials are mentioned as another color material used preferably.

(In the above formula (2), each m independently represents 1 or 2. M ₁ each independently represents a hydrogen atom, an alkali metal, an alkaline earth metal, a cation of an organic amine, or an ammonium ion.)

  Although it does not specifically limit as a suitable example shown to the said Formula (2), Specifically, the coloring material of a structure like the following Table 3 is mentioned. In Table 3, for the sake of convenience, the ring A and the ring B are represented by the following formula (3), and the positions of the sulfonic acid groups are shown. The substitution position of the sulfonic acid group is also defined by the following formula (3).

Although it does not specifically limit as a further favorable example of the compound shown to the said Formula (3), Specifically, the illustration compound Y1 shown to the following Formula is mentioned.

(Magenta color material)
C. I. Direct Red: 2, 4, 9, 11, 20, 23, 24, 31, 39, 46, 62, 75, 79, 80, 83, 89, 95, 197, 201, 218, 220, 224, 225, 226 227, 228, 229, 230, etc.
C. I. Acid Red: 6, 8, 9, 13, 14, 18, 26, 27, 32, 35, 42, 51, 52, 80, 83, 87, 89, 92, 106, 114, 115, 133, 134, 145 158, 198, 249, 265, 289, etc.
C. I. Food Red: 87, 92, 94, etc.
C. I. Direct violet: 107 etc.
C. I. Pigment Red: 2, 5, 7, 12, 48: 2, 48: 4, 57: 1, 112, 122, 123, 168, 184, 202, and the like.

(Cyan color material)
C. I. Direct blue: 1, 15, 22, 25, 41, 76, 77, 80, 86, 90, 98, 106, 108, 120, 158, 163, 168, 199, 226, 307, etc.
C. I. Acid Blue: 1, 7, 9, 15, 22, 23, 25, 29, 40, 43, 59, 62, 74, 78, 80, 90, 100, 102, 104, 112, 117, 127, 138, 158 161, 203, 204, 221, 244, etc.
C. I. Pigment Blue: 1, 2, 3, 15, 15: 2, 15: 3, 15: 4, 16, 22, 60, and the like.

Further, other color materials that can be preferably used include the following color materials.

(In the above formula (4), l = 0 to 2, m = 1 to 3, n = 1 to 3, provided that l + m + n = 3 to 4, and the substitution position of the substituent represents the 4-position or the 4′-position. M represents an alkali metal or ammonium, and R ₁ and R ₂ each independently represent a hydrogen atom, a sulfonic acid group, or a carboxyl group (except when R ₁ and R ₂ are simultaneously hydrogen atoms). Y represents a chlorine atom, a hydroxyl group, an amino group, or a mono- or dialkylamino group.)

The coloring material represented by the above formula (4) is synthesized using a phthalocyanine compound obtained by reacting 4-sulfophthalic acid derivative or 4-sulfophthalic acid derivative and (anhydrous) phthalic acid derivative in the presence of a metal compound as a raw material. . After converting a sulfonic acid group to a chlorosulfonic acid group, a phthalocyanine compound is obtained by reacting an aminating agent in the presence of an organic amine. That is, it is a phthalocyanine compound in which an unsubstituted sulfamoyl group (—SO ₂ NH ₂ ) and a substituted sulfamoyl group (the following formula (5)) are introduced limited to the 4th and 4 ′ positions in the above formula (4). have. It has been found that an ink using such a compound as a coloring material is extremely excellent in environmental gas resistance.

Specific examples of the compound represented by the above formula (5) include exemplified compounds having the following structure in the form of a free acid, and C1 exemplified compounds are particularly preferably used.

(Other color materials)
In addition to the ink of the present invention, the present invention can use other inks as necessary. Examples of color materials that can be contained in these inks are given below, but the present invention is not limited thereto.
C. I. Acid orange: 7, 8, 10, 12, 24, 33, 56, 67, 74, 88, 94, 116, 142, etc.
C. I. Acid Red: 111, 114, 266, 374, etc.
C. I. Direct orange: 26, 29, 34, 39, 57, 102, 118, etc.

C. I. Food orange: 3 etc.
C. I. Reactive orange: 1, 4, 5, 7, 12, 13, 14, 15, 16, 20, 29, 30, 84, 107, etc.
C. I. Disperse orange: 1, 3, 11, 13, 20, 25, 29, 30, 31, 32, 47, 55, 56, etc.
C. I. Pigment Orange: 43, etc.
C. I. Pigment Red: 122, 170, 177, 194, 209, 224 and the like.
C. I. Acid Green: 1, 3, 5, 6, 9, 12, 15, 16, 19, 21, 25, 28, 81, 84, etc.

C. I. Direct green: 26, 59, 67, etc.
C. I. Food green: 3 etc.
C. I. Reactive green: 5, 6, 12, 19, 21, etc.
C. I. Disperse Green: 6, 9 etc.
C. I. Pigment Green: 7, 36, etc.
C. I. Acid Blue: 62, 80, 83, 90, 104, 112, 113, 142, 203, 204, 221, 244, etc.
C. I. Reactive blue: 49 etc.
C. I. Acid violet: 17, 19, 48, 49, 54, 129, etc.
C. I. Direct violet: 9, 35, 47, 51, 66, 93, 95, 99, etc.

C. I. Reactive violet: 1, 2, 4, 5, 6, 8, 9, 22, 34, 36, etc.
C. I. Disperse violet: 1, 4, 8, 23, 26, 28, 31, 33, 35, 38, 48, 56, etc.
C. I. Pigment Blue: 15: 6, etc.
C. I. Pigment violet: 19, 23, 37 and the like.
C. I. Direct black: 17, 19, 22, 31, 32, 51, 62, 71, 74, 112, 113, 154, 168, 195, etc.
C. I. Acid Black: 2, 48, 51, 52, 110, 115, 156, etc.
C. I. Food black: 1, 2, etc.
Carbon black.

(Color material adsorption amount)
The inventors have also paid attention to the amount of colorant adsorbed on a recording medium containing a porous material having a cationic charge such as alumina for receiving ink in the ink receiving layer. The reason for focusing on the adsorption amount is that the adsorption amount of each color material to the ink receiving layer in the recording medium after the ink is applied to the recording medium affects the occurrence of color shift of the recorded matter. This is because.

When the amount of the following coloring material adsorbed on alumina is measured, it is as follows.
・ Exemplary Compound 1 45 mg / g Al ₂ O ₃
・ C. I. Direct Yellow 132 90mg / g Al ₂ O ₃
・ Exemplary Compound C1 94 mg / g Al ₂ O ₃
The exemplified compound C1 is a compound in which the exemplified compound C1 is substituted as a substituted sulfamoyl group on the phthalocyanine skeleton of the formula (4).

  The method for measuring the amount of adsorption onto alumina is to add a predetermined amount of alumina sol while stirring an aqueous dye solution having a known concentration, and sufficiently stir. After stirring, the mixture is centrifuged, the supernatant is filtered, and the amount of adsorption is calculated from the absorbance. C. I. Direct Yellow 132 and Exemplified Compound C1 have an adsorption amount of 90 mg or more on 1 g of alumina, whereas Exemplified Compound 1 is 45 mg. That is, it can be seen that Exemplified Compound 1 has a low adsorptive power to alumina. The fact that the amount of adsorption to alumina is low means that, as described above, the exemplary compound 1 has a considerable amount of color material that cannot be adsorbed in alumina as compared to other color materials, and color transition occurs. I think it may be one of the causes of the outbreak.

(Aqueous medium)
In the ink of the present invention, water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent can be used. In the ink of the present invention, it is necessary to contain 10% by mass or more of one or more water-soluble organic solvents having an evaporation rate of 70% or more. Furthermore, the proportion of the water-soluble organic solvent having an evaporation rate of 70% or more in all the water-soluble organic solvents in the ink needs to be 50% by mass or more. Examples of the water-soluble organic solvent having an evaporation rate of 70% or more include ethylene glycol, methanol, ethanol, and n-propanol. Of course, the present invention is not limited to these, and any water-soluble organic solvent having an evaporation rate of 70% or more measured by the above-described method can be used.

  Further, the ink of the present invention further includes a water-soluble organic solvent other than the water-soluble organic solvent having an evaporation rate of 70% or more, that is, a water-soluble organic solvent having an evaporation rate of less than 70%, if the above conditions are satisfied. It can be included. Examples of such water-soluble organic solvents include the following. Carboxylic acid amides such as N, N-dimethylformamide or N, N-dimethylacetamide. Ketones such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one, or keto alcohol. Cyclic ethers such as tetrahydrofuran and dioxane. Glycerin, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2- or 1,3-propylene glycol, 1,2- or 1,4-butylene glycol, polyethylene glycol and the like. 1,3-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, dithioglycol, 2-methyl-1,3-propanediol, 1,2,6- Hexanetriol etc. Polyhydric alcohols such as acetylene glycol derivatives and trimethylolpropane. 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. Heterocycles such as 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylmorpholine. Suitable examples include sulfur-containing compounds such as dimethyl sulfoxide.

  The water is preferably deionized water (ion exchange water). The water content is preferably 10% by mass or more and 90% by mass or less based on the total mass of the ink.

(Other additives)
In addition to this, the ink of the present invention includes urea, urea derivatives, and the like, surfactants, pH adjusters, chelating agents, rust preventives, antiseptics, antifungal agents, ultraviolet absorbers, viscosity adjusters. Various additives such as an antifoaming agent and a water-soluble polymer may be contained.

Examples of the surfactant include an anionic surfactant, an amphoteric surfactant, a cationic surfactant, and a nonionic surfactant.
The following are mentioned as an anionic surfactant. Alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurates, alkyl sulfates and the like. Moreover, polyoxyalkyl ether sulfate, alkyl sulfate, polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester salt, lauryl alcohol sulfate ester salt and the like. In addition, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylallyl sulfone hydrochloride, diethyl sulfosuccinate, diethylhexyl sulfosuccinate dioctyl sulfosuccinate and the like.

  Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Examples of amphoteric surfactants include the following. Lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, imidazoline derivatives and the like.

Nonionic surfactants include the following.
Ethers such as polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether.
Polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether.
Polyoxyethylene oleic acid, polyoxyethylene oleic acid ester, polyoxyethylene distearic acid ester and the like. Also, esters such as sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate.
2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol Acetylene glycol system such as. For example, acetylenol EH manufactured by Kawaken Fine Chemical Co., Ltd., Surfynol 104, 82, 465 manufactured by Nisshin Chemical Co., Ltd., orlphine STG can be used.

  As the pH adjusting agent, any substance can be used as long as it can control the pH of the ink within a predetermined range. For example, the following are mentioned. Alcoholamine compounds such as diethanolamine, triethanolamine, isopropanolamine, and trishydroxymethylaminomethane. Alkali metal hydroxides such as lithium hydroxide and potassium hydroxide. Ammonium hydroxide or alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate.

  Examples of antiseptic and antifungal agents include the following. Organic sulfur type, organic nitrogen sulfur type, organic halogen type, haloallylsulfone type, iodopropargyl type, N-haloalkylthio type, benzthiazole type, nitrile type, pyridine type, 8-oxyquinoline type. Also, benzothiazole, isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, and adamantane. In addition, compounds such as dithiocarbamate, brominated indanone, benzyl bromacetate, and inorganic salts may be mentioned.

Examples of the organic halogen compound include sodium pentachlorophenol. Examples of pyridine oxide compounds include sodium 2-pyridinethiol-1-oxide. An example of the inorganic salt compound is anhydrous sodium acetate. Examples of the isothiazoline-based compound include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, and 5-chloro-2-methyl-4-isothiazolin-3-one. Moreover, 5-chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, etc. are mentioned.
Other antiseptic and antifungal agents include sodium sorbate and sodium benzoate, such as Proxel GXL (S) and Proxel XL-2 (S) manufactured by Avecia.

  Examples of the chelating agent include sodium citrate, sodium ethylenediaminetetraacetate, sodium dinitrotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate and the like.

  Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

  Examples of the ultraviolet absorber include benzophenone compounds, benzotriazole compounds, cinnamic acid compounds, triazine compounds, and stilbene compounds. Alternatively, a compound that absorbs ultraviolet rays typified by a benzoxazole-based compound and emits fluorescence, a so-called fluorescent brightener can also be used.

Examples of the viscosity modifier include water-soluble polymer compounds in addition to water-soluble organic solvents, such as polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.
As the antifoaming agent, a fluorine-based or silicone-based compound is used as necessary.

(Ink set)
The ink of the present invention can be preferably used in an ink set combined with other inks. Furthermore, it is preferably used as an ink set of the ink of the present invention and the above-described combined ink. Of course, the ink included in the ink set may include inks other than the ink of the present invention and the combination ink described above. Particularly in the present invention, it is preferable that the ink of the present invention is used as at least one kind of ink among a plurality of ink sets, and all the other inks constituting the ink set are the above-described combined inks. The ink set according to the present invention is an ink cartridge in which a plurality of ink storage portions for storing each ink constituting the ink set are integrally formed, or each ink constituting the ink set is a separate ink cartridge. It also includes the use of combinations.

(Inkjet recording method)
The ink of the present invention can be preferably used in an ink jet recording method for recording on a recording medium by discharging the ink. In particular, it can be more preferably used in an ink jet recording method in which heat energy is applied to ink to perform recording on a recording medium.

(ink cartridge)
As an ink cartridge suitable for performing recording using the ink of the present invention, an ink cartridge having an ink containing portion for containing these inks may be mentioned. Specific examples of ink cartridges suitable for recording using the ink of the present invention are shown below. FIG. 1 is a schematic explanatory view and a cross-sectional view of an ink cartridge suitable for recording using the ink of the present invention.

  In FIG. 1, the ink cartridge communicates with the atmosphere via the atmosphere communication port 112 at the upper portion and communicates with the ink supply port at the lower portion. The ink cartridge is partitioned by a partition wall 138 into a negative pressure generating member storage chamber 134 that stores a negative pressure generating member therein and a substantially sealed liquid storage chamber 136 that stores liquid ink. Yes. The negative pressure generating member storage chamber 134 and the liquid storage chamber 136 are connected to the communication hole 140 formed in the partition wall 138 near the bottom of the ink cartridge, and to facilitate the introduction of the atmosphere into the liquid storage chamber during the liquid supply operation. Communication is performed only through the air introduction groove (atmosphere introduction path) 150. A plurality of ribs are integrally formed on the upper wall of the ink cartridge defining the negative pressure generating member storage chamber 134 so as to protrude inside, and the negative pressure generating member storage chamber 134 is stored in a compressed state. It is in contact with the pressure generating member. By this rib, an air buffer chamber is formed between the upper wall and the upper surface of the negative pressure generating member. The ink supply cylinder provided with the liquid supply port 114 is provided with a press contact body 146 having a higher capillary force and a higher physical strength than the negative pressure generating member, and is in pressure contact with the negative pressure generating member.

  In the negative pressure generating member storage chamber, as the negative pressure generating member, there are two capillary force generating negatives of the first negative pressure generating member 132B and the second negative pressure generating member 132A made of olefin resin fibers such as polyethylene. A pressure generating member is accommodated. Reference numeral 132C denotes a boundary layer between the two negative pressure generating members, and an intersection portion of the boundary layer 132C with the partition wall 138 is an atmosphere introduction groove (atmosphere introduction path) in the posture when the ink cartridge is used with the communication portion downward. It exists above the upper end of 150. Further, the ink accommodated in the negative pressure generating member exists above the boundary layer 132C as indicated by the ink level L.

  Here, the boundary layer between the first negative pressure generating member and the second negative pressure generating member is in pressure contact, and the vicinity of the boundary layer of the negative pressure generating member has a higher compressibility than other parts, and the capillary force Is in a strong state. That is, assuming that the capillary force of the first negative pressure generating member is P1, the capillary force of the second negative pressure generating member is P2, and the capillary force of the interface between the negative pressure generating members is PS, P2 <P1 <PS. It has become.

  FIG. 2 is a schematic explanatory view of still another ink cartridge suitable for recording using the ink of the present invention, and is a cross-sectional view. The ink cartridge includes a container 41 that stores ink of three colors, yellow (Y), magenta (M), and cyan (C), and a lid member 42 that covers the container 41. The interior of the container 41 is partitioned into three spaces having substantially the same capacity by two partition plates 411 and 412 arranged in parallel to each other in order to accommodate three colors of ink. These three spaces are aligned along the insertion direction of the ink cartridge when the color ink cartridge is mounted on the holder.

  In each of these spaces, an ink absorber 44Y that absorbs and holds yellow ink, an ink absorber 44M that absorbs and holds magenta ink, and an ink absorber 44C that absorbs and holds cyan ink. Is stored. Further, the ink stored in the ink absorber 44Y, the ink absorber 44M, and the ink absorber 44C, which are negative pressure generating members, reaches the top of each ink absorber as indicated by the ink level L. Existing.

  FIG. 3 is an exploded view of yet another ink cartridge that is suitable for recording using the ink of the present invention, and in which a recording head and an ink tank are integrated. The recording head is for discharging ink of three colors, cyan, magenta, and yellow, and has a configuration as shown in an exploded perspective view of FIG. That is, the recording element substrate H1101, the electric wiring tape H1301, the ink supply holding member H1501, the filters H1701, H1702, and H1703, the ink absorbers H1601, H1602, and H1603, the lid member H1901, and the seal member H1801.

  The ink supply holding member H1501 has an ink tank function and an ink supply function. That is, the ink supply holding member H1501 has a space for independently holding the absorbers H1601, H1602, and H1603 for generating negative pressure for holding cyan, magenta, and yellow inks therein. It functions as an ink tank. Further, the ink supply holding member H1501 fulfills an ink supply function by forming an independent ink channel for guiding ink to each ink supply port of the recording element substrate H1101. Ink absorbers H1601, H1602, and H1603 are made by compressing PP fibers, but may be compressed urethane fibers. Filters H1701, H1702, and H1703 for preventing dust from entering the inside of the recording element substrate H1101 are joined to the boundary portions with the ink absorbers H1601, H1602, and H1603 at the upstream portion of each ink flow path by welding. . Each of the filters H1701, H1702, and H1703 may be a SUS metal mesh type, but is preferably a SUS metal fiber sintered type.

  In addition, it is preferable that the shape of the ink supply holding member is aligned so that the surface area of the portion exposed to the atmosphere in each liquid chamber is substantially the same area, and thereby the amount of ink evaporation in each liquid chamber is aligned to some extent. Therefore, evaporation tends to be uniform for each ink, which is more preferable.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the text, “parts” and “%” are based on mass unless otherwise specified.

(Evaporation rate of water-soluble organic solvent)
The evaporation rate was determined as follows. 5 g of a water-soluble organic solvent was placed in a petri dish having an outer diameter of 31 mm and a height of 15 mm, and stored for 72 hours in an environment at a temperature of 60 ° C. Thereafter, the mass of the water-soluble organic solvent present in the petri dish (the mass of the water-soluble organic solvent after storage) was measured. From the obtained value and the mass of the water-soluble organic solvent charged (the mass of the water-soluble organic solvent before storage, here 5 g), the evaporation rate was calculated based on the following formula.

(1) Preparation of Magenta Ink Each of the components shown in Table 5 and Table 6 below was mixed and subjected to pressure filtration with a membrane filter having a pore size of 0.2 μm to obtain magenta ink 12 from magenta ink 1.

(2) Preparation of Ink A used in combination with Magenta Ink A was obtained by mixing the components shown in Table 7 below and pressure-filtering with a membrane filter having a pore size of 0.2 μm.

[Evaluation]
(Color change)
Since the color shift is a particularly remarkable phenomenon when the secondary color is recorded, in this embodiment, the secondary color is recorded and the effect is confirmed. Further, color transfer is a phenomenon that occurs when one ink contains an anthrapyridone-based compound and the other ink does not contain a color material. Therefore, in this embodiment, the effect of the present invention is confirmed with the secondary colors of magenta ink and clear ink. As a matter of course, as long as it falls within the scope of the present invention, the effect of the present invention can be obtained even when a secondary color is recorded using inks containing coloring materials.

The ink jet recording apparatus (trade name: PIXUS950i) manufactured by Canon was mounted with a combination of the magenta ink prepared in Tables 5 and 6 and the ink A prepared in Table 7. Thereafter, a secondary gradation patch was recorded on Canon Pro Photo Paper (trade name: PR-101). The secondary gradation patch is a patch in which a patch in which magenta ink is changed from 0% duty to 100% duty in steps of 10% duty is overlapped with ink 100% duty. CIE L ^* a ^* b ^* of a patch recorded with a 100% duty of magenta ink and a patch recorded with a total of 200% duty of magenta ink and ink A after light recording is left overnight, light source: D50, field of view: Measurements were made at 2 °. A spectrophotometer (Spectorolino; manufactured by Gretag Macbeth) was used for measurement of CIE L ^* a ^* b ^* . The value of CIE L ^* a ^* b ^* with a 100% magenta ink duty patch was defined as (L ₁ , a ₁ , b ₁ ). In addition, the value of CIE L ^* a ^* b ^* in a patch recorded with 100% duty of magenta ink and a patch recorded with a total of 200% duty of magenta ink and ink A is set to (L ₂ , a ₂ , b ₂ ). . Then, the color difference (ΔE) was calculated based on the following formula (6).

The calculated ΔE was determined according to the following evaluation criteria to evaluate the color shift.
A: ΔE is less than 2 B: ΔE is 2 or more and less than 3 X: ΔE is 3 or more The results are shown in Table 8.

(3) Preparation of Gray Ink Each component shown in Table 9 below was mixed and subjected to pressure filtration with a membrane filter having a pore size of 0.2 μm to obtain Gray 1 to Gray 5.

(4) Preparation of ink B to be used in combination with gray ink The components shown in Table 10 below were mixed and subjected to pressure filtration with a membrane filter having a pore size of 0.2 μm to obtain ink B.

(Evaluation)
The evaluation of the gray ink was performed by the same method and standard as the evaluation of the magenta ink. Table 11 shows the evaluation results of the color shift.

It is a schematic explanatory drawing of the ink cartridge suitable for recording using the ink of this invention. It is a schematic explanatory drawing of the ink cartridge suitable for recording using the ink of this invention. FIG. 3 is an exploded view of an ink cartridge in which a recording head and an ink tank suitable for recording using the ink of the present invention are integrated.

Explanation of symbols

41: Container 42: Lid members 43Y, 43M, 43C: Ink supply ports 44Y, 44M, 44C: Ink absorbers 45Y, 45M, 45C: Ink supply member 46: Retaining claw 47: Latch lever 47c: Base slope 48: Latch Claw 49: Stepped portion 112: Atmospheric communication port 114: Liquid supply port 132A: Second negative pressure generating member 132B: First negative pressure generating member 132C: First negative pressure generating member and second negative pressure generating member Boundary layer 134: negative pressure generating member storage chamber 136: liquid storage chamber 138: partition wall 140: communication hole 146: pressure contact body 150: air introduction groove (atmosphere introduction path)
411, 412: Partition plate H1101: Recording element substrate H1201: Ink supply port H1301: Electrical wiring tape H1302: External signal input terminal H1303: Opening portion H1304: Electrode terminal H1307: First sealant H1308: Second seal Agent H1501: Ink supply holding member H1590: Z abutting portions H1601, H1602, H1603: Ink absorbers H1701, H1702, H1703: Filter H1801: Seal member H1901: Lid members H1911, H1912, H1913: Fine ports H1921, H1922, H1923 : Fine groove L: Liquid-gas interface

Claims (5)

At least an inkjet ink containing a compound of the following formula (1) as a coloring material,
The compound of the following formula (1) has a solubilizing group number / molecular weight value of 2.0 × 10 ⁻³ or more,
The ink contains 10% by mass or more of one or more water-soluble organic solvents having an evaporation rate of 70% or more, and the evaporation rate in all the water-soluble organic solvents in the ink is 70%. An ink-jet ink, wherein the proportion of the water-soluble organic solvent is 50% by mass or more.

(In the above formula (1), R ¹ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted aryl group. R ² represents a hydrogen atom, an alkyl group, a hydroxyalkyl group, Represents a cyclohexyl group, a mono- or dialkylaminoalkyl group, or a cyanoalkyl group, R ³ represents a hydrogen atom, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted phenoxy group, and R ⁴ represents a hydrogen atom, substituted or Represents an unsubstituted alkyl group or a substituted or unsubstituted aryl group.)   A water-soluble organic solvent containing one or more water-soluble organic solvents having an evaporation rate of 70% or more in the ink and having an evaporation rate of 70% or more in all the water-soluble organic solvents in the ink. The inkjet ink according to claim 1, wherein the inkjet ink is used together with an ink in which the proportion of the solvent is 50% by mass or more. An ink set having a plurality of inks,
The ink for ink-jet recording according to claim 1, wherein at least one of the inks constituting the ink set is the ink-jet ink.
The other at least one ink constituting the ink set contains 10% by mass or more of one or more water-soluble organic solvents having an evaporation rate of 70% or more, and all the water-soluble organics in the ink An ink set, wherein a proportion of a water-soluble organic solvent having an evaporation rate of 70% or more in the solvent is 50% by mass or more.   An inkjet recording method for recording on a recording medium by ejecting ink by an inkjet method, wherein the ink is the inkjet ink according to claim 1 or 2.   An ink cartridge comprising an ink containing portion for containing ink, wherein the ink is the ink jet ink according to claim 1.

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