JP2010037504A - Ink set, inkjet-recording method, ink cartridge, recording unit, and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink set in which a plurality of inks each having both of image density and resistance to sticking required as an inkjet ink are combined and which satisfies excellent gas resistance in an image recorded with each ink and excellent gas resistance in an image of composite black recorded by superposing respective inks. <P>SOLUTION: The ink set for inkjet contains at least a black ink, a cyan ink, a magenta ink and a yellow ink, and the each ink contains a plurality of color materials in a specified content relation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inkjet ink set including a plurality of inks, and an inkjet recording method, an ink cartridge, a recording unit, and an inkjet recording apparatus using the ink set.

  The ink jet recording method is a recording method in which an ink droplet is applied to a recording medium such as plain paper or glossy media to form an image, and is rapidly spreading due to its low cost and high recording speed. In addition, the ink jet recording method has become widespread as an image output method comparable to a silver salt photograph with the rapid spread of digital cameras, in addition to the progress of image quality improvement of images obtained by this method. ing.

  In recent years, due to the minimization of ink droplets and the improvement of the color gamut associated with the introduction of multi-color inks, recorded images obtained by the ink jet recording method have become higher in image quality than ever. On the other hand, however, demands for color materials and inks are increasing, and more stringent characteristics are required in terms of reliability such as improved color development, adhesion resistance, and ejection stability.

  On the other hand, the problem of the ink jet recording method is that the obtained recorded matter is inferior in image storability. In general, the recorded matter obtained by the ink jet recording method has lower image storability than silver salt photographs. Specifically, when the recorded material is exposed to light, humidity, heat, or environmental gases that exist in the air for a long time, the color material on the recorded material deteriorates, causing a change in color tone or fading of the image. There is a problem that it is easy to do.

  Among the image storability, many proposals have been made so far in order to improve the light fastness of an image. For example, among the cyan, magenta, and yellow inks, there has been proposed a color material that can improve the light resistance of the image, particularly in each of the yellow and magenta inks having a low image light resistance. For example, for yellow ink, C.I. I. Ink containing Direct Yellow 86 (see Patent Document 1), C.I. I. There is a proposal regarding an ink containing Direct Yellow 173 (see Patent Document 2). As for the magenta ink, there are proposals relating to an ink containing a novel monoazo dye (see Patent Document 3) and an ink containing a novel anthrapyridone dye (see Patent Document 4).

In addition, image storability against environmental gases such as trace amounts of ozone, NOx, and SO ₂ present in the air, which is a major problem in image storability, is the gas resistance of images in cyan ink, which is most susceptible to the effects. Many proposals have been made to improve the above. For example, there is a proposal regarding an ink containing a novel phthalocyanine dye (see Patent Documents 5 and 6).

Furthermore, there is a proposal regarding an ink set in consideration of color balance in a recorded matter obtained from each ink. For example, there is a proposal relating to the use of a specific dye having excellent image fastness as a color material for each ink in order to improve image storage stability, mainly light resistance (see Patent Documents 7 to 10). In addition, there is a proposal regarding the use of a specific dye excellent in image fastness as a coloring material of each ink in order to improve image storage stability mainly including ozone resistance (see Patent Documents 11 and 12).
Japanese Patent Laid-Open No. 04-233975 Japanese Patent Laid-Open No. 02-233781 JP 05-073791 A Japanese Patent Application Laid-Open No. 11-209673 Japanese Patent Laid-Open No. 2002-249677 JP 2000-303009 A JP 2001-288392 A JP 2002-338853 A JP 2002-294111 A JP 2003-138169 A JP 2003-238850 A JP 2003-286423 A

  In order to obtain an ink that gives a recorded matter with excellent image storage stability, for example, there is an approach of using a color material having high fastness as a color material used for the ink. In other words, by devising the chemical structure of the color material, create a color material that is resistant to light and gas, and by using such a color material, create an ink that can provide recorded matter with excellent image storage stability. That is why.

  However, for example, for color materials corresponding to primary colors of yellow, magenta, and cyan, even if a color material that is strong against mischief is used, the image storability of a full-color recorded matter recorded using these inks is not necessarily excellent. It turns out that it is not always.

  In other words, each ink has a level of image storability required for each ink, and by combining these in a well-balanced manner, it becomes possible to produce a recorded matter having a total excellent image storability. is there.

  Accordingly, it is an object of the present invention to provide an ink set that satisfies the following characteristics in an ink set in which a plurality of inks that satisfy both image density and anti-sticking properties required as an inkjet ink are combined. Specifically, an object of the present invention is to provide an ink set satisfying excellent gas resistance in an image recorded with each ink and excellent gas resistance in a composite black image recorded by superimposing the respective inks. Another object of the present invention is to provide an ink jet recording method, an ink cartridge, a recording unit, and an ink jet recording apparatus using each ink constituting the ink set.

  The above object is achieved by the present invention described below. That is, the ink set according to the present invention is an ink jet ink set including at least a black ink, a cyan ink, a magenta ink, and a yellow ink, and includes the black ink, the cyan ink, the magenta ink, and the yellow ink. The ink is characterized by having an ink having the following constitution.

  The black ink includes at least a compound represented by the following general formula (I) as the first color material, a compound represented by the following general formula (II) as the second color material, and the following as the third color material: The compound represented by the general formula (III) is contained, and the content (mass%) of the first color material in the black ink is the sum (mass%) of the contents of all the color materials in the black ink. ) To 45.0% to 75.0%, and the content (% by mass) of the second color material in the black ink is equal to the content of all the color materials in the black ink. It is more than 12.0% and 40.0% or less with respect to the total (mass%).

(In general formula (I), A is an optionally substituted aromatic group or heterocyclic group, B is any group represented by the following general formulas (1) to (5), M Are each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In the general formulas (1) to (5), R _{1 to} R ₉ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, carboxyl group, carbamoyl group, alkoxycarbonyl group, Aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxyl group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, Amino group including anilino group and heterocyclic amino group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group , Nitro group, An alkyl or arylsulfonyl group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group, or a sulfonic acid group, and each group is further substituted May be.)

(In the general formula (II), each R ₁₀ is independently a hydrogen atom, a hydroxyl group, a carboxyl group, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms which may be substituted by an alkoxy group having 1 to 4 carbon atoms. 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms Substituted by 4 alkylamino groups, carboxyl-alkylamino groups having 1 to 5 carbon atoms, bis- [carboxy-alkyl having 1 to 5 carbon atoms] amino groups, hydroxyl groups or alkoxy groups having 1 to 4 carbon atoms. C1-C4 alkanoylamino group, carboxyl group or sulfonic acid A phenylamino group, a sulfonic acid group, a halogen atom, or a ureido group which may be substituted with a group or an amino group, [C] is an aliphatic amine residue having a carboxyl group or a sulfonic acid group, and M is Each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In General Formula (III), D is a phenyl group having a substituent, and the substituent includes a carboxyl group, a sulfonic acid group, a chlorine atom, a cyano group, a nitro group, a sulfamoyl group, and a carbon number of 1 to 4. An alkyl group, an alkoxy group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, or a carboxyl group), and an alkylsulfonyl group having 1 to 4 carbon atoms; Selected from the group consisting of (which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group) E and F are each independently a paraphenylene group having a substituent, and the substituent is a carboxyl group Group, sulfonic acid group, alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms (hydroxyl group, alkoxy group having 1 to 4 carbon atoms, sulfo group) Selected from the group consisting of an acid group or a carboxyl group, and an alkylsulfonyl group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group). R ₁₁ is any one of an alkyl group having 1 to 4 carbon atoms which may be substituted with a carboxyl group, a phenyl group which may be substituted with a sulfonic acid group, or a carboxyl group, and R ₁₂ is a cyano group. A group, a carbamoyl group, or a carboxyl group, and R ₁₃ and R ₁₄ are each independently a hydrogen atom, a methyl group, a chlorine atom, or a sulfonic acid group.)
The cyan ink contains at least a compound represented by the following general formula (IV) as the first color material and a compound represented by the following general formula (V) as the second color material, The content (mass%) of the first color material is 1.25 times or more and 5.0 by mass ratio with respect to the content (mass%) of the second color material in the cyan ink. Is less than double.

(In general formula (IV), A, B, C, and D are each independently a six-membered aromatic ring, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. , E is an alkylene group, and X is a sulfo-substituted anilino group, a carboxyl-substituted anilino group, or a phosphono-substituted anilino group, and the substituted anilino group further includes a sulfonic acid group, a carboxyl group, a phosphono group, and a sulfamoyl group. Carbamoyl group, hydroxyl group, alkoxy group, amino group, alkylamino group, dialkylamino group, arylamino group, diarylamino group, acetylamino group, ureido group, alkyl group, nitro group, cyano group, halogen, alkylsulfonyl group, And at least one substituent selected from the group consisting of an alkylthio group and 1 to 4 Y is a hydroxyl group or an amino group, and l (el), m, and n are 0 ≦ l (el) ≦ 2, 0 ≦ m ≦ 3, and 0.1 ≦ n ≦ 3. And l (el) + m + n = 1 to 4.)

(In the general formula (V), X ₁ , X ₂ , X ₃ and X ₄ are each independently —SO—Z, —SO ₂ —Z, —SO ₂ NR ₁ R ₂ , a sulfonic acid group, —CONR. ₁ R ₂ or CO ₂ R ₁ , where Z is independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, substituted or unsubstituted An aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, wherein R ₁ and R ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted group, A cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. And, in the general formula _{(V), Y 1, Y} 2, Y 3, Y 4, Y 5, Y 6, Y 7, and _{Y 8} are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted Alkyl group, substituted or unsubstituted aryl group, cyano group, substituted or unsubstituted alkoxy group, amide group, ureido group, sulfonamido group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted sulfamoyl group, substituted or An unsubstituted alkoxycarbonyl group, a carboxyl group, or a sulfonic acid group, and a1, a2, a3, and a4 represent the number of substituents of X ₁ , X ₂ , X ₃ , and X ₄ , respectively, 1 is an integer of 1 or 2.
The magenta ink contains at least a compound represented by the following general formula (VI) as the first color material and a compound represented by the following general formula (VII) as the second color material. The content (mass%) of the first color material is 2.5 times or more 10.0 by mass ratio with respect to the content (mass%) of the second color material in the magenta ink. Is less than double.

(In the general formula (VI), each R is independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a cyclohexyl group, or a mono- or dialkylaminoalkyl group, and each M is independently a hydrogen atom, an alkali metal, or ammonium. Or an organic ammonium, and X is a linking group.)

(In General Formula (VII), R ₂ , R ₃ , R ₄ , and R ₅ are each independently an alkyl group, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. )
The yellow ink contains at least a compound represented by the following general formula (VIII) as a first color material and a compound represented by the following general formula (IX) as a second color material, The content (% by mass) of the first color material is 1.0 times or more and 10.0 by mass ratio with respect to the content (% by mass) of the second color material in the yellow ink. Is less than double.

(In General Formula (VIII), R ₁ , R ₂ , Y ₁ and Y ₂ are each independently a monovalent group, and X ₁ and X ₂ are each independently having a Hammett's σp value of 0.20 or more. Z ₁ and Z ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted group An aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In General Formula (IX), R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a sulfonic acid group, n is 1 or 2, and m is 1 to 3) X is an integer of 2 to 4, y is an integer of 1 to 3, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)
An ink jet recording method according to another embodiment of the present invention is an ink jet recording method for recording on a recording medium by ejecting ink by an ink jet method, and the ink constituting the ink set having the above-described configuration is used as the ink. It is characterized by using.

  An ink cartridge according to another embodiment of the present invention is an ink cartridge including an ink storage portion that stores ink, and the ink stored in the ink storage portion constitutes an ink set having the above-described configuration. Any ink is used.

  A recording unit according to another embodiment of the present invention is a recording unit including an ink storage unit that stores ink and a recording head for discharging ink, and is stored in the ink storage unit. The ink is any one of the inks constituting the ink set having the above-described configuration.

  In addition, an ink jet recording apparatus according to another embodiment of the present invention is an ink jet recording apparatus including an ink storage portion that stores ink and a recording head for ejecting ink, and is stored in the ink storage portion. The ink thus formed is any ink constituting the ink set having the above-described configuration.

  According to the present invention, it is possible to provide an ink set that satisfies the following characteristics in an ink set in which a plurality of inks that satisfy both image density and anti-sticking properties required as an inkjet ink are combined. Specifically, it is possible to provide an ink set that satisfies excellent gas resistance in an image recorded with each ink and excellent gas resistance in a composite black image recorded by superimposing each ink. Further, according to another embodiment of the present invention, an ink jet recording method, an ink cartridge, a recording unit, and an ink jet recording apparatus using each ink constituting the ink set can be provided.

  Details will be described below with reference to preferred embodiments of the present invention. In the present invention, when the color material is a salt, at least a part of the salt exists in the ink by dissociating into ions, but it is expressed as “contains a salt” for convenience. In the following description, when N is I to IX, the compound represented by the general formula (N) may be abbreviated as “compound of the general formula (N)”.

<Ink set>
The ink set of the present invention is used for inkjet, and contains at least black ink, cyan ink, magenta ink, and yellow ink, preferably further gray ink. Furthermore, the ink set of the present invention may have two or more types of so-called dark ink and light ink having substantially the same hue and different color material contents. Specifically, it is preferable that the cyan ink includes a dark cyan ink and a light cyan ink as two types of cyan inks having different color material contents. Further, it is preferable that the magenta ink includes a dark magenta ink and a light magenta ink as two types of magenta inks having different colorant contents.

  The ink set in the present invention is an ink cartridge that is integrally configured by combining a state of an ink cartridge that independently accommodates a plurality of inks and a plurality of ink accommodating portions that respectively accommodate a plurality of inks. State. The ink cartridge may have a configuration in which a recording head is integrally formed. Alternatively, the ink set of the present invention also includes a state in which the ink cartridges that individually contain the plurality of inks are configured to be detachable from the ink jet recording apparatus. Of course, the ink set of the present invention is not limited to these forms.

(Color material of black ink and its content)
The black ink constituting the ink set of the present invention has the following configuration. The black ink is at least a compound represented by the following general formula (I) as the first color material, a compound represented by the following general formula (II) as the second color material, and the following general as the third color material: A compound represented by the formula (III) is contained. And it is necessary to satisfy | fill the relationship mentioned later about content of these each color material.

(In general formula (I), A is an optionally substituted aromatic group or heterocyclic group, B is any group represented by the following general formulas (1) to (5), M Are each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In the general formulas (1) to (5), R _{1 to} R ₉ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, carboxyl group, carbamoyl group, alkoxycarbonyl group, Aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxyl group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, Amino group including anilino group and heterocyclic amino group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group , Nitro group, An alkyl or arylsulfonyl group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group, or a sulfonic acid group, and each group is further substituted May be.)

(In the general formula (II), each R ₁₀ is independently a hydrogen atom, a hydroxyl group, a carboxyl group, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms which may be substituted by an alkoxy group having 1 to 4 carbon atoms. 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms Substituted by 4 alkylamino groups, carboxyl-alkylamino groups having 1 to 5 carbon atoms, bis- [carboxy-alkyl having 1 to 5 carbon atoms] amino groups, hydroxyl groups or alkoxy groups having 1 to 4 carbon atoms. C1-C4 alkanoylamino group, carboxyl group or sulfonic acid A phenylamino group, a sulfonic acid group, a halogen atom, or a ureido group which may be substituted with a group or an amino group, [C] is an aliphatic amine residue having a carboxyl group or a sulfonic acid group, and M is Each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In General Formula (III), D is a phenyl group having a substituent, and the substituent includes a carboxyl group, a sulfonic acid group, a chlorine atom, a cyano group, a nitro group, a sulfamoyl group, and a carbon number of 1 to 4. An alkyl group, an alkoxy group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, or a carboxyl group), and an alkylsulfonyl group having 1 to 4 carbon atoms; Selected from the group consisting of (which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group) E and F are each independently a paraphenylene group having a substituent, and the substituent is a carboxyl group Group, sulfonic acid group, alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms (hydroxyl group, alkoxy group having 1 to 4 carbon atoms, sulfo group) Selected from the group consisting of an acid group or a carboxyl group, and an alkylsulfonyl group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group). R ₁₁ is any one of an alkyl group having 1 to 4 carbon atoms which may be substituted with a carboxyl group, a phenyl group which may be substituted with a sulfonic acid group, or a carboxyl group, and R ₁₂ is a cyano group. A group, a carbamoyl group, or a carboxyl group, and R ₁₃ and R ₁₄ are each independently a hydrogen atom, a methyl group, a chlorine atom, or a sulfonic acid group.)
In particular, the compound of general formula (I) is the following exemplary compound [K1], the compound of general formula (II) is the following exemplary compound [K2], and the compound of general formula (III) is the following exemplary compound [ K3] is more preferable.

  As described above, the first color material (compound of general formula (I)), the second color material (compound of general formula (II)), and the third color material (general formula (III)) in the black ink. Each content (% by mass) of the compound (1) must satisfy the following relationship from the viewpoint of color tone and light resistance.

  The content (% by mass) of the first color material in the black ink is 45.0% or more and 75.0% or less with respect to the total content (% by mass) of all the color materials in the black ink. There must be. That is, the value of [first color material / all color materials in ink] × 100 needs to be 45.0% or more and 75.0% or less. When the value of [first color material / all color materials in ink] × 100 is less than 45.0% or exceeds 75.0%, black ink is displayed in an image having gradation (initial image). As a result, a preferable color tone cannot be obtained.

  The content (mass%) of the second color material in the black ink is greater than 12.0% and 40.0% or less with respect to the total content (mass%) of all the color materials in the black ink. It needs to be. That is, the value of [second color material / all color materials in ink] × 100 needs to be greater than 12.0% and not greater than 40.0%. Furthermore, the value of [second color material / all color materials in ink] × 100 is preferably greater than 12.0% and not greater than 25.0%. When the value of [second color material / all color materials in ink] × 100 is 12.0 or less, a color tone preferable as black ink is obtained in an image having gradation (initial image). There may not be. When the value of [second color material / all color materials in ink] × 100 exceeds 40.0%, a color tone preferable as a black ink is obtained in an image having gradation (after a light resistance test). It may not be obtained.

  In the present invention, the first color material (compound of general formula (I)), the second color material (compound of general formula (II)), and the third color material (general formula (II)) in the black ink are further included. It is preferable that each content (mass%) of the compound (III) satisfies the following relationship.

  The content (mass%) of the third color material in the ink is based on the total content (mass%) of all the color materials in the ink, that is, [the third color material / all the ink in the ink Colorant] × 100 is preferably 4.0% or more and 40.0% or less. Further, the value of [third color material / all color materials in ink] × 100 is preferably 4.0% or more and 25.0% or less. If the value of [third color material / all color materials in ink] × 100 is less than 4.0% or exceeds 40.0%, an image having gradation (after the initial image and light resistance test) ), A color tone preferable as a black ink may not be obtained. In particular, when the value of [third color material / all color materials in ink] × 100 is 4.0% or more and 25.0% or less, even in an image having gradation, Also in the image after the light resistance test, the color tone as a black ink becomes more preferable.

  Further, the total content (mass%) of the first color material, the second color material, and the third color material in the black ink is 0.1 mass% or more and 15. It is preferable that it is 0 mass% or less. Furthermore, the total (mass%) of these contents is more preferably 0.5 mass% or more and 10.0 mass% or less. If the total of these contents is less than 0.1% by mass, sufficient color developability may not be obtained. On the other hand, if the total of these contents exceeds 15.0% by mass, the anti-sticking property may be obtained. Inkjet characteristics such as may not be obtained.

  The content (% by mass) of the first color material in the black ink is preferably 50.0% or more with respect to the total content (% by mass) of all the color materials in the black ink. Next, the content (mass%) of the second color material in the black ink is 0.60 times or more in mass ratio with respect to the content (mass%) of the third color material in the black ink. It is preferably less than 1.00 times. This is because, by using black ink that satisfies these two conditions, an image having gradation (initial image) can be made an image having a more neutral tone. In this case, the upper limit of the content (mass%) of the first color material in the black ink is 75.0% or less with respect to the total content (mass%) of all the color materials in the black ink. It is preferable that

The color tone preferable as the black ink in the present invention, that is, the color tone that is neutral and gives a preferable image means the following. For an image having gradation that is recorded using black ink with the recording duty reduced from 100%, the a ^* and b in the L ^* a ^* b ^* display system defined by the CIE (International Lighting Commission) ^{* Is} measured. An ink having a ^* and b ^* values of −5 ≦ a ^* ≦ 5 and −5 ≦ b ^* ≦ 5 at least in a portion where the recording duty is 100% is preferable as a black ink in the present invention. It is said that the ink has Furthermore, an ink satisfying the following rules is an ink having a more preferable color tone as a black ink in the present invention. That is, the values of a ^* and b ^* in the portion where the recording duty is 100% are −5 ≦ a ^* ≦ 5 and −5 ≦ b ^* ≦ 5, and in each gradation recorded with the recording duty reduced, a ^* And b ^* are preferably −10 ≦ a ^* ≦ 10 and −10 ≦ b ^* ≦ 10. The values of a ^* and b ^* can be measured using, for example, a spectrophotometer (trade name: Spectrolino; manufactured by Gretag Macbeth). Of course, the present invention is not limited to this.

(Color material of cyan ink and its content)
The cyan ink constituting the ink set of the present invention has the following configuration. The cyan ink contains at least a compound represented by the following general formula (IV) as the first color material and a compound represented by the following general formula (V) as the second color material. And it is necessary to satisfy | fill the relationship mentioned later about content of these each color material.

(In general formula (IV), A, B, C, and D are each independently a six-membered aromatic ring, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. , E is an alkylene group, and X is a sulfo-substituted anilino group, a carboxyl-substituted anilino group, or a phosphono-substituted anilino group, and the substituted anilino group further includes a sulfonic acid group, a carboxyl group, a phosphono group, and a sulfamoyl group. Carbamoyl group, hydroxyl group, alkoxy group, amino group, alkylamino group, dialkylamino group, arylamino group, diarylamino group, acetylamino group, ureido group, alkyl group, nitro group, cyano group, halogen, alkylsulfonyl group, And at least one substituent selected from the group consisting of an alkylthio group and 1 to 4 Y is a hydroxyl group or an amino group, and l (el), m, and n are 0 ≦ l (el) ≦ 2, 0 ≦ m ≦ 3, and 0.1 ≦ n ≦ 3. And l (el) + m + n = 1 to 4.)

(In the general formula (V), X ₁ , X ₂ , X ₃ and X ₄ are each independently —SO—Z, —SO ₂ —Z, —SO ₂ NR ₁ R ₂ , a sulfonic acid group, —CONR. ₁ R ₂ or CO ₂ R ₁ , where Z is independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, substituted or unsubstituted An aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, wherein R ₁ and R ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted group, A cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. And, in the general formula _{(V), Y 1, Y} 2, Y 3, Y 4, Y 5, Y 6, Y 7, and _{Y 8} are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted Alkyl group, substituted or unsubstituted aryl group, cyano group, substituted or unsubstituted alkoxy group, amide group, ureido group, sulfonamido group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted sulfamoyl group, substituted or An unsubstituted alkoxycarbonyl group, a carboxyl group, or a sulfonic acid group, and a1, a2, a3, and a4 represent the number of substituents of X ₁ , X ₂ , X ₃ , and X ₄ , respectively, 1 is an integer of 1 or 2.
Particularly, the compound of the general formula (IV) is the following exemplified compound [C1], and the compound of the general formula (V) is the following exemplified compounds [C2-1], [C2-2], and [C2-3]. More preferably, it is a mixture of

  As described above, each content (% by mass) of the first color material (compound of general formula (IV)) and the second color material (compound of general formula (V)) in cyan ink is ozone resistant. From the viewpoint of sex, it is necessary to satisfy the following relationship.

  The content (mass%) of the first color material in the cyan ink is 1.25 times or more by mass ratio with respect to the content (mass%) of the second color material in the cyan ink. Must be less than 0 times. Furthermore, the mass ratio is particularly preferably 1.5 times or more and 3.0 times or less. As a result of the study by the present inventors, when the first color material and the second color material are mixed, there is a correlation between these mass ratios and ozone resistance, and the effect of improving ozone resistance is particularly noticeable. It was found that the mass ratio of the content is in the above range. That is, when this mass ratio is satisfied, a particularly excellent ozone resistance is obtained that far exceeds the performance predicted from the ozone resistance possessed by the compound of general formula (IV) or the compound of general formula (V). be able to. In addition, by setting the mass ratio of the content within the above range, it is possible to obtain a color tone preferable as a cyan ink. When the mass ratio exceeds 5.0, the influence of mixing the coloring materials on the cohesiveness is small, and the ozone resistance is close to the performance when these coloring materials are used alone. Further, since the color tone of the ink is also biased toward the red direction, a color tone preferable as cyan ink cannot be obtained. On the other hand, when the mass ratio is less than 1.25, the influence of mixing the coloring materials on the cohesiveness is small, and the ozone resistance is close to the performance when these coloring materials are used alone. Further, since the color tone of the ink is also biased toward the green direction, a color tone preferable for cyan ink cannot be obtained. In other words, in the present invention, by mixing the first color material and the second color material at a specific mass ratio, the ozone resistance of the image far exceeding the predicted level and the color tone preferable as the cyan ink are obtained. Can be achieved particularly remarkably.

  In the present invention, each content (% by mass) of the first color material (compound of general formula (IV)) and the second color material (compound of general formula (V)) in the cyan ink is It is preferable to satisfy the following relationship.

  The content (% by mass) of the first color material in the cyan ink is preferably 0.1% by mass or more and 10.0% by mass or less based on the total mass of the ink. In addition, the content (% by mass) of the second color material in the cyan ink is preferably 0.1% by mass or more and 10.0% by mass or less based on the total mass of the ink.

  Further, the total content (% by mass) of the first color material and the second color material in the cyan ink is 0.1% by mass or more and 20.0% by mass or less based on the total mass of the ink. It is preferable. Furthermore, the total content (% by mass) of the content is particularly preferably 0.5% by mass or more and 10.0% by mass or less. If the total content is less than 0.1% by mass, sufficient ozone resistance and color developability may not be obtained. If the total content exceeds 20.0% by mass, such as anti-sticking property. Ink jet characteristics may not be obtained.

The preferable color tone for the cyan ink in the present invention means the following. For an image recorded using cyan ink at a recording duty of 100%, a ^* and b ^* in an L ^* a ^* b ^* display system defined by the CIE (International Commission on Illumination) are measured. An ink having a hue angle (H °) calculated based on the following formula from the obtained a ^* and b ^* values of 237 ° or more and 244 ° or less is preferable as a cyan ink in the present invention. It is said that the ink has The values of a ^* and b ^* can be measured using, for example, a spectrophotometer (trade name: Spectrolino; manufactured by Gretag Macbeth). Of course, the present invention is not limited to this.
When a ^* ≧ 0 and b ^* ≧ 0 (first quadrant), H ° = tan ⁻¹ (b ^* / a ^* )
^{a * ≦ 0, b * ≧} 0 in (second ^{quadrant), H ° = 180 + tan} -1 (b * / a *)
When a ^* ≦ 0 and b ^* ≦ 0 (third quadrant), H ° = 180 + tan ⁻¹ (b ^* / a ^* )
When a ^* ≧ 0 and b ^* ≦ 0 (fourth quadrant), H ° = 360 + tan ⁻¹ (b ^* / a ^* ).

(Coloring material of magenta ink and its content)
The magenta ink constituting the ink set of the present invention has the following configuration. The magenta ink contains at least a compound represented by the following general formula (VI) as the first color material and a compound represented by the following general formula (VII) as the second color material. And it is necessary to satisfy | fill the relationship mentioned later about content of these each color material.

(In the general formula (VI), each R is independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a cyclohexyl group, or a mono- or dialkylaminoalkyl group, and each M is independently a hydrogen atom, an alkali metal, or ammonium. Or an organic ammonium, and X is a linking group.)

(In General Formula (VII), R ₂ , R ₃ , R ₄ , and R ₅ are each independently an alkyl group, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. )
In particular, the compound of the general formula (VI) is more preferably the following exemplary compound [M1], and the compound of the general formula (VII) is more preferably the following exemplary compound [M2].

  As described above, each content (% by mass) of the first color material (compound of general formula (VI)) and the second color material (compound of general formula (VII)) in the magenta ink is a color tone, From the viewpoint of light resistance and gas resistance, it is necessary to satisfy the following relationship.

  The content (mass%) of the first color material in the magenta ink is 2.5 times or more 10.0 by mass ratio with respect to the content (mass%) of the second color material in the magenta ink. It is necessary to be less than twice. By combining the ink so that the mass ratio of the contents of the first color material and the second color material falls within the above range, the following two synergistic effects exceeding expectations can be obtained. First, the first synergistic effect is an improvement beyond the expected light resistance of an image recorded with ink. That is, the light resistance of the image obtained by the compound of the compound of the general formula (VI) and the light resistance of the image obtained by the compound of the general formula (VII), which are predicted from the light resistance of the combination, are far greater. The light resistance of the image exceeding the level is obtained. Next, the second synergistic effect is to improve the color tone of an image recorded with ink. That is, an image having a color tone preferable as a magenta ink can be obtained by using the first color material and the second color material in combination so that the mass ratio of the content of the first color material and the second color material falls within the above range. In the case of an ink in which the mass ratio of the contents of the first color material and the second color material is less than 2.5 times or more than 10.0 times, these synergistic effects are not exhibited. That is, no dramatic improvement in light resistance is observed compared to the light resistance of the image obtained when each of the first color material and the second color material is used alone, and the preferred color tone for the magenta ink It is not possible to get the image. Furthermore, the mass ratio is preferably 3.0 times or more and 10.0 times or less, and particularly preferably 9.0 times or more and 10.0 times or less.

  In the present invention, each content (% by mass) of the first color material (compound of general formula (VI)) and the second color material (compound of general formula (VII)) in the magenta ink is It is preferable to satisfy the following relationship.

  The content (% by mass) of the first color material in the magenta ink is preferably 2.5% by mass or more and 10.0% by mass or less based on the total mass of the ink. Further, the content (% by mass) of the second color material in the magenta ink is preferably 0.5% by mass or more and 2.0% by mass or less based on the total mass of the ink.

  Further, the total content (% by mass) of the first color material and the second color material in the magenta ink is 4.0% by mass or more and 10.0% by mass or less based on the total mass of the ink. It is preferable. When the total content (% by mass) is less than 4.0% by mass, the image density of the recorded matter may not be sufficiently obtained, and the total content (% by mass) is 10.0% by mass. If it exceeds, ink jet characteristics such as anti-sticking property may not be obtained.

The preferable color tone for the magenta ink in the present invention means the following. For an image recorded using magenta ink at a recording duty of 100%, a ^* and b ^* in the L ^* a ^* b ^* display system defined by the CIE (International Commission on Illumination) are measured. An ink having a hue angle (H °) calculated based on the following formula from 0 to 5 ° or 350 ° to less than 360 ° from the obtained values of a ^* and b ^* In the invention, the ink has a preferable color tone as the magenta ink. Furthermore, an ink having a hue angle (H °) calculated based on the following formula of 0 ° or more and 5 ° or less is regarded as an ink having a particularly preferable color tone as a magenta ink in the present invention. The values of a ^* and b ^* can be measured using, for example, a spectrophotometer (trade name: Spectrolino; manufactured by Gretag Macbeth). Of course, the present invention is not limited to this.
When a ^* ≧ 0 and b ^* ≧ 0 (first quadrant), H ° = tan ⁻¹ (b ^* / a ^* )
When a ^* ≦ 0 and b ^* ≧ 0 (second quadrant), H ° = 180 + tan ⁻¹ (b ^* / a ^* )
For a ^* ≦ 0 and b ^* ≦ 0 (third quadrant), H ° = 180 + tan ⁻¹ (b ^* / a ^* )
For a ^* ≧ 0 and b ^* ≦ 0 (fourth quadrant), H ° = 360 + tan ⁻¹ (b ^* / a ^* ).

(Color material and content of yellow ink)
The yellow ink constituting the ink set of the present invention has the following configuration. The yellow ink contains at least a compound represented by the following general formula (VIII) as the first color material and a compound represented by the following general formula (IX) as the second color material. And it is necessary to satisfy | fill the relationship mentioned later about content of these each color material.

(In General Formula (VIII), R ₁ , R ₂ , Y ₁ and Y ₂ are each independently a monovalent group, and X ₁ and X ₂ are each independently having a Hammett's σp value of 0.20 or more. Z ₁ and Z ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted group An aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In General Formula (IX), R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a sulfonic acid group, n is 1 or 2, and m is 1 to 3) X is an integer of 2 to 4, y is an integer of 1 to 3, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)
In particular, the compound of the general formula (VIII) is more preferably the following exemplary compound [Y1], and the compound of the general formula (IX) is more preferably the following exemplary compound [Y2].

  As described above, each content (% by mass) of the first color material (compound of general formula (VIII)) and the second color material (compound of general formula (IX)) in the yellow ink is light resistance. From the viewpoints of color developability, color tone, and ink storage stability, the following relationship must be satisfied.

  The content (mass%) of the first color material in the yellow ink is 1.0 times or more and 10.0 in mass ratio with respect to the content (mass%) of the second color material in the yellow ink. It is necessary to be less than twice. By setting the mass ratio of the content within the above range, a synergistic effect is exhibited, and the light resistance, color developability, color tone, and ink storage stability of the image can be obtained particularly effectively. Furthermore, when the mass ratio is 1.0 to 5.0, it is predicted from the combination of the light resistance of the compound of the general formula (VIII) and the light resistance of the compound of the general formula (IX). It is particularly preferable because a high level of light resistance that far exceeds the performance obtained can be obtained. The use of the first color material and the second color material at a specific mass ratio provides a synergistic effect, and the reason why light resistance exceeding prediction is not clearly understood, but the present inventors. Guesses as follows. Since the compound of the general formula (VIII) is originally low in solubility, when an ink containing these compounds is applied to a recording medium, the color materials are rapidly associated and aggregated immediately after that. The association or aggregation tends to improve the fastness of the color material on the recording medium constituting the image. On the other hand, however, excessive association or aggregation may reduce the light fastness inherent in the molecular structure. On the other hand, by allowing the compound of the general formula (IX) to coexist, the compound of the general formula (VIII) records the optimum association and aggregation state with respect to the light resistance on the recording medium. It is thought that the property improved.

  In the present invention, each content (mass%) of the first color material (compound of general formula (VIII)) and the second color material (compound of general formula (IX)) in the yellow ink is It is preferable to satisfy the following relationship.

  The content (% by mass) of the first color material in the yellow ink is preferably 0.1% by mass or more and 10.0% by mass or less based on the total mass of the ink. Further, the content (% by mass) of the second color material in the yellow ink is preferably 0.1% by mass or more and 10.0% by mass or less based on the total mass of the ink.

  In addition, the total content (% by mass) of the first color material and the second color material in the yellow ink is 1.0% by mass or more and 10.0% by mass or less based on the total mass of the ink. Is particularly preferably 1.5% by mass or more and 6.0% by mass or less. When the total content is less than 1.0% by mass, the light resistance and color developability of the recorded matter may not be sufficiently obtained. When the total content exceeds 10.0% by mass, the anti-adhesion property Ink jet characteristics such as property may not be obtained.

  The color tone preferable as the yellow ink in the present invention means the following two things. First, it means that an image recorded using only yellow ink is not reddish or greenish. In addition, when a secondary color image recorded using yellow ink, that is, an image of a red region or a green region is recorded, both the red region and the green region may be greatly lost. Means having no color tones.

More specifically, a ^* and b ^* in an L ^* a ^* b ^* display system defined by the CIE (International Lighting Commission) is measured for an image recorded with yellow ink and a recording duty of 60%. . An ink having a hue angle (H °) calculated based on the following formula from the obtained a ^* and b ^* values of 85 ° or more and 92 ° or less is preferable as a yellow ink in the present invention. It is said that the ink has Furthermore, an ink having a hue angle (H °) calculated based on the following formula of 88 ° or more and 90 ° or less is regarded as an ink having a particularly preferable color tone as a yellow ink in the present invention. The values of a ^* and b ^* can be measured using, for example, a spectrophotometer (trade name: Spectrolino; manufactured by Gretag Macbeth). Of course, the present invention is not limited to this.
When a ^* ≧ 0 and b ^* ≧ 0 (first quadrant), H ° = tan ⁻¹ (b ^* / a ^* )
When a ^* ≦ 0 and b ^* ≧ 0 (second quadrant), H ° = 180 + tan ⁻¹ (b ^* / a ^* )
For a ^* ≦ 0 and b ^* ≦ 0 (third quadrant), H ° = 180 + tan ⁻¹ (b ^* / a ^* )
For a ^* ≧ 0 and b ^* ≦ 0 (fourth quadrant), H ° = 360 + tan ⁻¹ (b ^* / a ^* ).

(Gray ink coloring material and its content)
The gray ink constituting the ink set of the present invention has the following configuration. The gray ink is a compound represented by the general formula (IV) as the first color material, a compound represented by the general formula (VIII) as the second color material, and a general formula (VII) as the third color material. The compound represented, and the compound represented by general formula (I) is contained as a 4th color material.

(In general formula (IV), A, B, C, and D are each independently a six-membered aromatic ring, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. , E is an alkylene group, and X is a sulfo-substituted anilino group, a carboxyl-substituted anilino group, or a phosphono-substituted anilino group, and the substituted anilino group further includes a sulfonic acid group, a carboxyl group, a phosphono group, and a sulfamoyl group. Carbamoyl group, hydroxyl group, alkoxy group, amino group, alkylamino group, dialkylamino group, arylamino group, diarylamino group, acetylamino group, ureido group, alkyl group, nitro group, cyano group, halogen, alkylsulfonyl group, And at least one substituent selected from the group consisting of an alkylthio group and 1 to 4 Y is a hydroxyl group or an amino group, and l (el), m, and n are 0 ≦ l (el) ≦ 2, 0 ≦ m ≦ 3, and 0.1 ≦ n ≦ 3. And l (el) + m + n = 1 to 4.)

(In General Formula (VIII), R ₁ , R ₂ , Y ₁ and Y ₂ are each independently a monovalent group, and X ₁ and X ₂ are each independently having a Hammett's σp value of 0.20 or more. Z ₁ and Z ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted group An aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In General Formula (VII), R ₂ , R ₃ , R ₄ , and R ₅ are each independently an alkyl group, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. )

(In general formula (I), A is an optionally substituted aromatic group or heterocyclic group, B is any group represented by the following general formulas (1) to (5), M Are each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In the general formulas (1) to (5), R _{1 to} R ₉ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, carboxyl group, carbamoyl group, alkoxycarbonyl group, Aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxyl group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, Amino group including anilino group and heterocyclic amino group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group , Nitro group, An alkyl or arylsulfonyl group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group, or a sulfonic acid group, and each group is further substituted May be.)
In particular, the compound of general formula (IV) is exemplified compound [C1], the compound of general formula (VIII) is exemplified compound [Y1], the compound of general formula (VII) is exemplified compound [M2], and the compound of general formula (I) More preferably, the compound is Exemplified Compound [K1].

(Color material verification method)
To verify whether or not the color material used in the present invention is contained in each ink, the following verification methods (1) to (3) using high performance liquid chromatography (HPLC) can be applied.

(1) Peak retention time (2) Maximum absorption wavelength for peak (1) (3) M / Z (posi), M / Z (negative) of mass spectrum for peak (1)
(Aqueous medium)
For each ink constituting the ink set 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. It is preferable to use deionized water (ion exchange water) as the water. The content (% by mass) of water in the ink is preferably 10.0% by mass or more and 90.0% by mass or less based on the total mass of the ink.

  The water-soluble organic solvent is not particularly limited as long as it is water-soluble, and alcohol, polyhydric alcohol, polyglycol, glycol ether, nitrogen-containing polar solvent, sulfur-containing polar solvent and the like can be used. The content (% by mass) of the water-soluble organic solvent in the ink is 5.0% by mass or more and 90.0% by mass or less, and further 10.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. It is preferable that

  Specifically, for example, the following water-soluble organic solvents can be used. Alkyl alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol; Amides such as dimethylformamide and dimethylacetamide. Ketones or ketoalcohols such as acetone and diacetone alcohol. Ethers such as tetrahydrofuran and dioxane. Polyalkylene glycols such as polyethylene glycol and polypropylene glycol. Glycols such as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, hexylene glycol, and thiodiglycol. Alkylene groups such as 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 1,2,6-hexanetriol Alkylene glycols having 2 to 6 carbon atoms. Bis (2-hydroxyethyl) sulfone. Alkyl ether acetates such as polyethylene glycol monomethyl ether acetate. Alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether. Glycerin. N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like. Of course, the present invention is not limited to these. These water-soluble organic solvents can be used alone or in combination of two or more as required.

  Each ink constituting the ink set of the present invention contains at least one selected from glycerin, ethylene glycol, diethylene glycol, 2-pyrrolidone, urea, ethylene urea, and 1,5-pentanediol as a water-soluble organic solvent. Is preferred. By using an ink containing such a water-soluble organic solvent, it is possible to improve ejection characteristics in various environments and recovery reliability when the ink is left for a long period of time. In particular, by using at least three kinds selected from the above-mentioned water-soluble organic solvents in combination, it is possible to make it applicable to high-speed recording by effectively suppressing an increase in the viscosity of the ink. It can be set as the ink which expresses an effect especially notably.

(Additive)
Each ink constituting the ink set of the present invention is solid at room temperature, such as polyhydric alcohols such as trimethylolpropane and trimethylolethane, and urea derivatives such as ethyleneurea, as necessary, in addition to the components described above. The water-soluble organic compound may be contained. Furthermore, each of the inks constituting the ink set of the present invention includes a surfactant, a pH adjuster, a rust inhibitor, a preservative, an antifungal agent, an antioxidant, a reduction inhibitor, an evaporation accelerator, and a chelate as necessary. Various additives such as an agent and a water-soluble polymer may be contained. In particular, compounds such as trisodium citrate and proxel GXL (manufactured by Avicia) can be used particularly suitably for imparting properties such as long-term reliability stability to the ink.

(Ink physical properties)
Each ink constituting the ink set of the present invention preferably has a viscosity in the range of 2.0 to 2.6 mPa · s at room temperature (25 ° C.) in order to be applicable to high-speed recording.

<Recording medium>
As the recording medium used for recording an image using each ink constituting the ink set of the present invention, any recording medium can be used as long as the recording medium performs recording by applying ink. In the present invention, it is preferable to use an ink jet recording medium in which a coloring material such as a dye or a pigment is adsorbed to fine particles forming the porous structure of the ink receiving layer. In particular, it is preferable to use a recording medium having a so-called gap absorption type ink receiving layer that absorbs ink by voids formed in the ink receiving layer on the support. The gap absorption type ink receiving layer is composed mainly of fine particles, and may further contain a binder and other additives as necessary.

<Inkjet recording method>
Each of the inks constituting the ink set of the present invention is particularly preferably used in the ink jet recording method of the present invention in which ink is ejected by an ink jet method to perform recording on a recording medium. Ink jet recording methods include a recording method in which ink is ejected by applying mechanical energy to the ink, and a recording method in which ink is ejected by applying thermal energy to the ink. In particular, in the present invention, an ink jet recording method using thermal energy can be preferably used.

<Ink cartridge>
As an ink cartridge suitable for performing recording using each ink constituting the ink set of the present invention, the ink cartridge of the present invention provided with an ink storage portion for storing each of these inks can be cited.

<Recording unit>
As a recording unit suitable for recording using each ink constituting the ink set of the present invention, an ink storage unit for storing these inks and a recording head for discharging these inks were provided. The recording unit of the present invention may be mentioned. In particular, a recording unit in which the recording head ejects ink by applying thermal energy corresponding to the recording signal to the ink can be preferably used. In particular, in the present invention, it is preferable to use a recording head having a heat generating part wetted surface containing a metal and / or a metal oxide. Specific examples of the metal and / or metal oxide constituting the heat generating part wetted surface include, for example, metals such as Ta, Zr, Ti, Ni, and Al, and oxides of these metals. .

<Inkjet recording apparatus>
As an ink jet recording apparatus suitable for performing recording using each ink constituting the ink set of the present invention, the present invention includes an ink storage portion for storing the ink and a recording head for discharging the ink. Inkjet recording apparatus. In particular, there is an ink jet recording apparatus that ejects ink by applying thermal energy corresponding to a recording signal to ink inside a recording head having an ink storage portion that stores the ink.

  Below, the schematic structure of the mechanism part of an inkjet recording device is demonstrated. The ink jet recording apparatus is composed of a paper feed unit, a transport unit, a carriage unit, a paper discharge unit, a cleaning unit, and an exterior unit that protects these parts and provides design properties in accordance with the role of each mechanism.

  FIG. 1 is a perspective view of the ink jet recording apparatus. 2 and 3 are diagrams for explaining the internal mechanism of the ink jet recording apparatus. FIG. 2 is a perspective view from the upper right part, and FIG. 3 is a side sectional view of the ink jet recording apparatus.

  When paper is fed, only a predetermined number of recording media are fed to a nip portion composed of a paper feed roller M2080 and a separation roller M2041 in a paper feed unit including a paper feed tray M2060. The recording medium is separated at the nip portion, and only the uppermost recording medium is conveyed. The recording medium conveyed to the conveyance unit is guided by the pinch roller holder M3000 and the paper guide flapper M3030, and conveyed to the roller pair of the conveyance roller M3060 and the pinch roller M3070. The roller pair of the conveyance roller M3060 and the pinch roller M3070 is rotated by driving of the LF motor E0002, and the recording medium is conveyed on the platen M3040 by this rotation.

  When recording an image on a recording medium, the carriage unit arranges a recording head H1001 (FIG. 4; detailed configuration will be described later) at a position for recording a target image, and follows a signal from the electric board E0014. Ink is ejected onto the recording medium. An image is recorded on the recording medium by alternately repeating main scanning in which the carriage M4000 scans in the column direction while performing recording by the recording head H1001 and sub-scanning in which the recording medium is conveyed in the row direction by the conveyance roller M3060. The recording medium on which the image is recorded is conveyed in a state sandwiched between the nips of the first paper discharge roller M3110 and the spur M3120 in the paper discharge unit, and is discharged to the paper discharge tray M3160.

  The cleaning unit cleans the recording head H1001 before and after recording an image. When the pump M5000 is operated with the cap M5010 capping the ejection port of the recording head H1001, unnecessary ink or the like is sucked from the ejection port of the recording head H1001. In addition, by sucking ink remaining in the cap M5010 with the cap M5010 open, sticking due to the remaining ink and other problems do not occur.

(Configuration of recording head)
The configuration of the head cartridge H1000 will be described. FIG. 4 is a diagram showing the structure of the head cartridge H1000, and is a diagram showing how the ink cartridge H1900 is mounted on the head cartridge H1000. The head cartridge H1000 has a recording head H1001, means for mounting the ink cartridge H1900, and means for supplying ink from the ink cartridge H1900 to the recording head, and is detachably mounted on the carriage M4000.

  The ink jet recording apparatus records an image with yellow, magenta, cyan, black, light magenta, light cyan, and gray inks. Therefore, the ink cartridge H1900 is also prepared for seven colors independently. In the above, the ink constituting the ink set of the present invention is used as at least one ink. As shown in FIG. 4, each ink cartridge H1900 is detachable from the head cartridge H1000. The ink cartridge H1900 can be attached and detached even when the head cartridge H1000 is mounted on the carriage M4000.

  FIG. 5 is an exploded perspective view of the head cartridge H1000. The head cartridge H1000 includes a recording element substrate, a plate, an electric wiring substrate H1300, a cartridge holder H1500, a flow path forming member H1600, a filter H1700, a seal rubber H1800, and the like. The recording element substrate is composed of a first recording element substrate H1100 and a second recording element substrate H1101, and the plate is composed of a first plate H1200 and a second plate H1400.

  The first recording element substrate H1100 and the second recording element substrate H1101 are Si substrates, and a plurality of recording elements (nozzles) for ejecting ink are formed on one side thereof by a photolithography technique. Electric wiring such as Al for supplying electric power to each recording element is formed by a film forming technique, and a plurality of ink flow paths corresponding to individual recording elements are formed by a photolithography technique. Further, an ink supply port for supplying ink to the plurality of ink flow paths is formed to open on the back surface.

  FIG. 6 is an enlarged front view illustrating the configuration of the first recording element substrate H1100 and the second recording element substrate H1101. H2000 to H2600 are arrays of printing elements corresponding to different ink colors (hereinafter also referred to as nozzle arrays). On the first recording element substrate H1100, nozzle rows for three colors, a nozzle row H2000 for yellow ink, a nozzle row H2100 for magenta ink, and a nozzle row H2200 for cyan ink, are formed. On the second recording element substrate H1101, nozzle rows for four colors, a light cyan ink nozzle row H2300, a black ink nozzle row H2400, a gray ink nozzle row H2500, and a light magenta ink nozzle row H2600, are formed. ing. Of course, the type of ink and the arrangement of the nozzle rows are not limited to these.

  Hereinafter, a description will be given with reference to FIGS. The first recording element substrate H1100 and the second recording element substrate H1101 are bonded and fixed to the first plate H1200. Here, an ink supply port H1201 for supplying ink to the first recording element substrate H1100 and the second recording element substrate H1101 is formed. Further, a second plate H1400 having an opening is bonded and fixed to the first plate H1200. The second plate H1400 holds the electrical wiring substrate H1300 so that the electrical wiring substrate H1300 is electrically connected to the first recording element substrate H1100 and the second recording element substrate H1101.

  The electrical wiring substrate H1300 applies an electrical signal for ejecting ink from each nozzle formed on the first recording element substrate H1100 and the second recording element substrate H1101. The electric wiring board H1300 is arranged on the electric wiring corresponding to the first recording element substrate H1100 and the second recording element substrate H1101, and an external part for receiving an electric signal from the ink jet recording apparatus. And a signal input terminal H1301. The external signal input terminal H1301 is positioned and fixed on the back side of the cartridge holder H1500.

  A flow path forming member H1600 is fixed to the cartridge holder H1500 that holds the ink cartridge H1900, for example, by ultrasonic welding, and forms an ink flow path H1501 that communicates from the ink cartridge H1900 to the first plate H1200. A filter H1700 is provided at the ink cartridge side end of the ink flow path H1501 that engages with the ink cartridge H1900, and can prevent dust from entering from the outside. Further, a seal rubber H1800 is attached to the engaging portion with the ink cartridge H1900 so that the ink can be prevented from evaporating from the engaging portion.

  Furthermore, as described above, the head cartridge H1000 is configured by bonding the cartridge holder portion and the recording head portion H1001 by bonding or the like. The cartridge holder portion includes a cartridge holder H1500, a flow path forming member H1600, a filter H1700, and a seal rubber H1800. The recording head portion H1001 includes a first recording element substrate H1100, a second recording element substrate H1101, a first plate H1200, an electric wiring substrate H1300, and a second plate H1400.

  Here, as an embodiment of the recording head, a thermal ink jet recording head that performs recording using an electrothermal transducer (recording element) that generates thermal energy for causing ink to cause film boiling in accordance with an electrical signal. Said. About this typical structure and principle, for example, what is performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 is preferable. . This method can be applied to both a so-called on-demand type and a continuous type.

  The thermal ink jet method is particularly effective when applied to an on-demand type. In the case of the on-demand type, at least one drive that applies a rapid temperature rise exceeding nucleate boiling corresponding to the recording information to the electrothermal transducer disposed corresponding to the liquid flow path holding the ink Apply a signal. As a result, thermal energy is generated in the electrothermal transducer, and film boiling occurs in the ink. As a result, bubbles in the ink corresponding to the drive signal on a one-to-one basis can be formed. At least one droplet is formed by ejecting ink through the ejection port by the growth and contraction of the bubbles. It is more preferable that the driving signal has a pulse shape, since the bubble grows and contracts immediately and appropriately, so that ink discharge with particularly excellent response can be achieved.

  In addition, the ink constituting the ink set of the present invention is not limited to the thermal ink jet method, and can be preferably used in an ink jet recording apparatus using mechanical energy as described below. An ink jet recording apparatus having such a configuration includes a nozzle forming substrate having a plurality of nozzles, a pressure generating element made of a piezoelectric material and a conductive material disposed to face the nozzles, and ink filling the periphery of the pressure generating element. Become. Then, the pressure generating element is displaced by the applied voltage, and ink is ejected from the nozzle.

  As described above, the ink jet recording apparatus is not limited to one in which the recording head and the ink cartridge are separated from each other. Further, the ink cartridge is integrated with the recording head in a separable or non-separable manner and mounted on the carriage, and is provided at a fixed portion of the ink jet recording apparatus via an ink supply member such as a tube. An ink may be supplied to the recording head. Further, when the ink cartridge is provided with a configuration for applying a preferable negative pressure to the recording head, the following configuration can be adopted. That is, a mode in which an absorber is disposed in the ink storage portion of the ink cartridge, or a mode in which a flexible ink storage bag and a spring portion that applies a biasing force in the direction of expanding the inner volume of the flexible ink storage bag are provided. It can be. The ink jet recording apparatus may take the form of a line printer in which recording elements are aligned over a range corresponding to the entire width of the recording medium, in addition to the serial type recording method described above.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited at all by the following Example, unless the summary is exceeded. Hereinafter, “part” or “%” is based on mass unless otherwise specified.

<Synthesis of coloring materials>
(Exemplary compound [K1])
Exemplified compound [K1] was synthesized according to the method described in JP-A-2005-139427.

(Exemplary compound [K2])
Exemplified compound [K2] was synthesized according to the method described in International Publication No. 2006/001274 pamphlet.

(Exemplary compound [K3])
The sodium salt type exemplary compound [K3] was synthesized according to the following procedures (A) to (D).

(A) Synthesis of Compound of Formula (7) In 100 parts of water, 25.3 parts of 2-aminobenzene-1,5-disulfonic acid was dissolved to pH 5.0 to 6.0 by adding sodium hydroxide. After adding 31.3 parts of 35% hydrochloric acid to this, the temperature of the liquid was adjusted to 0 to 5 ° C., and 19.0 parts of 40% sodium nitrite aqueous solution was added to diazotize. To this diazo solution, 24.0 parts of the compound of the following formula (6) obtained by the method described in JP-A-2004-083492 is added to 240 parts of water, and the pH is adjusted to 4.5 to 5.5 by adding sodium hydroxide. The dissolved liquid was added dropwise over about 20 minutes. Thereafter, the temperature of the liquid was adjusted to 10 to 20 ° C., and the pH of the liquid was adjusted to 2.0 to 3.0 by adding sodium carbonate, and the mixture was stirred for 3 hours while maintaining this temperature and pH. Thereafter, salting out was performed by adding sodium chloride, and the precipitate was filtered, separated and dried to obtain 42.1 parts of a compound of the following formula (7).

(B) Synthesis of compound of formula (8) 7.6 parts of the compound of formula (7) obtained above is suspended in 40 parts of water and dissolved to pH 4.0-5.0 by adding sodium hydroxide. did. After adding 6.0 parts of 35% hydrochloric acid to this solution, the temperature of the liquid was adjusted to 15 to 25 ° C., and 2.9 parts of 40% aqueous sodium nitrite solution was added for diazotization. The diazo suspension was dissolved in 30 parts of water and 30 parts of water to a pH of 4.5 to 5.5 by adding sodium hydroxide. The solution was added dropwise over about 30 minutes as the temperature. During the dropwise addition, the pH of the solution was maintained at 3.5 to 4.5 by adding sodium carbonate. Thereafter, the mixture was stirred for 2 hours, salted out by adding sodium chloride, and the precipitate was filtered and separated to obtain a wet cake containing a disazo compound of the following formula (8).

(C) Synthesis of Compound of Formula (10) 2- (Cyanomethyl) benzimidazole and ethyl acetoacetate were heated and reacted in ethanol in the presence of sodium methoxide. 8.9 parts of the compound of the following formula (9) obtained by aciding out by adding dilute hydrochloric acid was slowly added to 64 parts of 6% fuming sulfuric acid at a temperature of 15 to 25 ° C. Then, after stirring at the same temperature for 2 hours, the obtained liquid was dripped over 190 parts of ice water over about 10 minutes. The precipitated crystals were filtered, separated, and dried to obtain a compound of the following formula (10).

(D) Synthesis of Exemplary Compound [K3] The wet cake containing the disazo compound of formula (8) obtained in (B) above was adjusted to pH 6.0 to 7.0 by adding sodium hydroxide to 80 parts of water. Then, 2.3 parts of 40% aqueous sodium nitrite solution was added thereto. Thereafter, this solution was dropped into a mixed solution of 5.2 parts of 35% hydrochloric acid and 70 parts of water at a temperature of 20 to 30 ° C. to diazotize. This diazo suspension was dissolved in a solution obtained by dissolving 3.0 parts of the compound of the formula (10) obtained in the procedure (C) in 50 parts of water to pH 8.0 to 9.0 by adding sodium hydroxide. The solution was added dropwise at a temperature of 20 to 30 ° C. During the addition, the pH of the solution was maintained at 7.0 to 8.0 by adding sodium carbonate. Thereafter, the mixture was stirred at the same temperature for 2 hours, salted out by adding sodium chloride, and the precipitate was filtered and separated. The obtained wet cake was dissolved in 50 parts of water, and then crystallized by adding 120 parts of methanol, and the precipitate was filtered and separated. The obtained wet cake was further dissolved in 50 parts of water, crystallized by adding 120 parts of methanol, and dried to obtain an exemplary compound [K3] (sodium salt). The maximum absorption wavelength (λ _max ) of the absorption spectrum of the obtained exemplary compound [K3] measured using water as a solvent was 557.5 nm.

(Exemplary compound [C1])
Exemplified compound [C1] was synthesized according to the following procedures (A) to (D).

  (A) Synthesis of compound of formula (11)

  To 2,000 parts of ice water, 7.2 parts of Rotat OH-104K (manufactured by Lion) and 239.9 parts of cyanuric chloride were added and stirred for 30 minutes. To this, 411.6 parts of aniline-2,5-disulfonic acid monosodium salt (purity 91.2%) was added, and while adding a 25% aqueous sodium hydroxide solution, the pH of the reaction solution was adjusted to 2.7 to 2.7. The reaction was carried out at 10 to 15 ° C. for 1 hour and then at 27 to 30 ° C. for 2 hours. Next, after cooling the reaction liquid to 10 ° C. or lower, a 25% aqueous sodium hydroxide solution was added to adjust the pH of the reaction liquid to 7.0 to 7.5. To this, 118.4 parts of 28% aqueous ammonia was added, and the temperature was adjusted to 10 to 15 ° C. and the pH was adjusted to 9.5 to 10.0 and maintained for 3 hours. Thereafter, concentrated hydrochloric acid was added to adjust the pH of the reaction solution to 6.0 to 7.0. Next, 2,000 parts of ice was added, cooled to 0 ° C., and 780 parts of ethylenediamine was added dropwise while maintaining the temperature at 5 ° C. or lower. Thereafter, the temperature of the reaction solution was kept at 10 to 15 ° C. for 1 hour. Subsequently, concentrated hydrochloric acid was added dropwise thereto to adjust the pH of the reaction solution to 0.9 to 1.0. During this time, the temperature of the reaction solution was kept at 10 to 15 ° C. by adding ice so that the temperature did not rise. Furthermore, ice was added thereto, and the temperature of the reaction solution was cooled to 10 ° C. or lower. The liquid volume at this time was 13,000 parts. To this reaction liquid, 2,600 parts of sodium chloride (20% with respect to the liquid amount) was added and stirred for 1 hour to precipitate crystals. The precipitated crystals were collected by filtration and washed with 3,000 parts of a 20% aqueous sodium chloride solution to obtain 743.0 parts of a wet cake (purity: 59.3%, HPLC purity: 93.3%).

  (B) Synthesis of copper tribenzo (2,3-pyrido) porphyrazine [compound of formula (12): a mixture in which one of the four aromatic rings of the copper phthalocyanine ring is a pyridine ring and the remaining three are benzene rings]

In a four flask, 250 parts sulfolane, 22.1 parts phthalimide, 8.4 parts quinolinic acid, 72.0 parts urea, 8.8 parts copper (II) chloride dihydrate (purity 97.0%), 1.0 part of ammonium molybdate was added, and the reaction solution was heated to 200 ° C. and kept for 5 hours. After completion of the reaction, the reaction solution was cooled to 75 ° C., 200 parts of methanol was added, and the precipitated crystals were filtered. The obtained crystal was washed with 250 parts of methanol and subsequently with 500 parts of hot water to obtain 61.9 parts of a wet cake. The obtained wet cake was added to 500 parts of 5% hydrochloric acid, and the liquid was heated to 60 ° C. and kept for 1 hour. The obtained crystals were filtered and washed with 300 parts of water. Subsequently, the obtained wet cake was added to 500 parts of 10% ammonia water, and the temperature of the liquid was adjusted to 25 to 30 ° C. and maintained for 1 hour. Thereafter, the obtained crystals were filtered and washed with 300 parts of water to obtain 64.9 parts of a wet cake. The obtained wet cake was dried at 80 ° C. to obtain 20.9 parts of blue crystals. As a result of analyzing this blue crystal, the maximum absorption wavelength (λ _max ) is 670.5 nm (in pyridine), the constituent element is C ₃₁ H ₁₅ N ₉ Cu, and the elemental analysis value is the value shown in Table 1 below. I found out. As a result, it was confirmed that the obtained blue crystal was a compound of the formula (12) having the above structure.

  (C) Copper tribenzo (2,3-pyrido) porphyrazine trisulfonyl chloride [compound of formula (13): a mixture in which one of the outermost aromatic rings of the main component in the mixture is a pyridine ring and the remaining three are benzene rings ]

  Into 46.2 parts of chlorosulfonic acid, 5.8 parts of copper tribenzo (2,3-pyrido) porphyrazine obtained in (B) above was gradually charged with stirring while maintaining the liquid temperature at 60 ° C. or lower. Thereafter, the reaction was carried out at 140 ° C. for 4 hours. Next, the reaction solution was cooled to 70 ° C., 17.9 parts of thionyl chloride was added dropwise over 30 minutes, and the mixture was reacted at 70 ° C. for 3 hours. The reaction solution is cooled to 30 ° C. or lower, slowly poured into 500 parts of ice water, the precipitated crystals are filtered, washed with 200 parts of cold water, and wet with copper tribenzo (2,3-pyrido) porphyrazine trisulfonyl chloride. 71.1 parts of cake were obtained.

  (D) Compound of Formula (14) [Exemplary Compound [C1]: One of the outermost aromatic rings of the main component in the mixture is a pyridine ring and the remaining three are benzene rings, b is 2.4, and c is 0 Of a mixture of .6]

To 200 parts of ice water, 71.1 parts of a wet cake of copper tribenzo (2,3-pyrido) porphyrazine trisulfonyl chloride (compound of formula (13)) obtained in (C) above was added and stirred. Suspended. Next, what melt | dissolved 20.5 parts of compounds (purity: 59.3%) of the formula (11) obtained by said (A) in 3.0 parts of aqueous ammonia and 100 parts of warm water was added. To this, the pH of the reaction solution was maintained at 9.0 to 9.3 by adding 28% ammonia water, and the reaction solution was allowed to react at a temperature of 17 to 20 ° C. for 6 hours. Thereafter, the temperature of the reaction solution was raised to 60 ° C. The liquid volume at this time was 500 parts. To this, 100 parts of sodium chloride (20% with respect to the liquid volume) was added, and 35% hydrochloric acid aqueous solution was added to adjust the pH of the liquid to 1.0 to precipitate crystals. The precipitated crystals were collected by filtration and washed with 100 parts of a 20% aqueous sodium chloride solution to obtain 47.7 parts of a wet cake. The obtained wet cake was dissolved again in water to adjust the pH of the liquid to 9.0, then the total amount was adjusted to 300 parts, and the temperature of the liquid was raised to 60 ° C. The liquid volume at this time was 320 parts. To this, 48 parts of sodium chloride (15% with respect to the liquid amount) was added, and a 35% hydrochloric acid aqueous solution was added to adjust the pH of the liquid to 1.0 to precipitate crystals. The precipitated crystals were separated by filtration and washed with 100 parts of a 15% aqueous sodium chloride solution to obtain 47.8 parts of a wet cake. 47.8 parts of the obtained wet cake was added to 250 parts of methanol and suspended by stirring at 60 ° C. for 1 hour, followed by filtration, washing with 100 parts of methanol, and drying to obtain blue crystals (formula (14) 10.7 parts of the above compound) was obtained. As a result of analyzing this blue crystal, the maximum absorption wavelength (λ _max ) was 611 nm (in an aqueous solution). The resulting compound of formula (14) was ion-exchanged by a conventional method to obtain a sodium salt type exemplified compound [C1].

(Exemplary compounds [C2-1], [C2-2], and a mixture of [C2-3])
A mixture of exemplary compounds [C2-1], [C2-2], and [C2-3] was synthesized according to the method described in Japanese Patent No. 3851569.

(Exemplary compound [M1])
Exemplified compound [M1] was synthesized according to the method described in JP-A-2006-143989.

(Exemplary compound [M2])
Exemplified compound [M2] was synthesized according to the procedures (A) to (G) shown below.

  (A) In 360 parts of xylene, 94.8 parts of the compound of the following formula (15), 3.0 parts of sodium carbonate, and 144.0 parts of benzoylacetic acid ethyl ester are sequentially added under stirring, and the liquid temperature is adjusted to 140 to The temperature was raised to 150 ° C. and the reaction was carried out for 8 hours. Meanwhile, ethanol and water produced by the reaction were distilled out of the system while azeotroping with xylene to complete the reaction. The reaction solution was cooled to a temperature of 30 ° C., 240 parts of methanol was added, and the mixture was stirred for 30 minutes. Thereafter, the precipitated solid was collected by filtration. The obtained solid was washed with 360 parts of methanol and then dried to obtain 124.8 parts of a compound of the following formula (16) as pale yellow needle crystals.

  (B) In 300.0 parts of N, N-dimethylformamide, 88.8 parts of the compound of the formula (16) obtained above, 75.0 parts of metaaminoacetanilide, 24.0 parts of copper acetate monohydrate , And 12.8 parts of sodium carbonate were added sequentially with stirring. And the temperature of the liquid was raised to 120-130 degreeC, and reaction was performed for 3 hours. The reaction solution was cooled to about 50 ° C., 120 parts of methanol was added, and the mixture was stirred for 30 minutes. Thereafter, the precipitated solid was collected by filtration. The obtained solid was washed with 500 parts of methanol and then with warm water of 80 ° C. and then dried to obtain 79.2 parts of a compound of the following formula (17) as bluish red crystals.

  (C) To 130 parts of 98% sulfuric acid, 170 parts of 28% fuming sulfuric acid was added with stirring under water to prepare 300 parts of 12% fuming sulfuric acid. While cooling with water, 51.3 parts of the compound of the formula (17) obtained above was added at a temperature of 50 ° C. or lower, and then the temperature of the liquid was raised to 85 to 90 ° C. and reacted for 4 hours. The reaction solution was added to 600 parts of ice water, and while the ice was added, the rise in the solution temperature due to heat generation was suppressed, and the solution temperature was kept at 40 ° C. or lower. Further, water was added to bring the amount of the reaction solution to 1,000 parts, followed by filtration to remove undissolved substances. Warm water was added to the obtained mother liquor to make 1,500 parts, while maintaining the liquid temperature at 60 to 65 ° C., 300 parts of sodium chloride was added and stirred for 2 hours, and the precipitated crystals were collected by filtration. The obtained crystals were washed with 300 parts of a 20% aqueous sodium chloride solution and thoroughly squeezed to obtain 100.3 parts of a wet cake containing 59.2 parts of the compound of the following formula (18) as red crystals.

  (D) In 60 parts of water, 67.7 parts of the wet cake of the compound of the formula (18) obtained above was added. Next, 24 parts of 25% aqueous sodium hydroxide solution was added thereto and stirred, and further dissolved by adjusting the pH of the liquid to 3 to 4 by adding 25% aqueous sodium hydroxide solution. On the other hand, 0.4 parts of Lipar OH (trade name, anionic surfactant; manufactured by Lion) was added to 60 parts of ice water, and 8.9 parts of cyanuric chloride was added thereto, followed by stirring for 30 minutes. Got. The obtained suspension was added to the solution containing the compound of the formula (18) obtained above. Then, using a 10% aqueous sodium hydroxide solution, the reaction of the compound of the following formula (19) is carried out at a temperature of 25 to 30 ° C. for 4 hours while keeping the pH of the liquid at 2.7 to 3.0. A containing reaction solution was obtained.

  (E) 9.5 parts of sodium p-phenolsulfonate dihydrate was added to the reaction solution containing the compound of the formula (19) obtained above. Next, 25% aqueous sodium hydroxide solution was added to this, and while maintaining the pH of the liquid at 6.5 ± 0.3, the temperature of the liquid was raised to 50 to 55 ° C., and the reaction was performed at that temperature for 1 hour. To obtain a reaction solution containing a compound of the following formula (20).

  (F) 1.2 parts of ethylenediamine was added to the reaction liquid containing the compound of the formula (20) obtained above. Next, a 25% aqueous sodium hydroxide solution was added thereto, and while maintaining the pH of the liquid at 7.8-8.2, the temperature of the liquid was raised to 78-82 ° C. and kept at that temperature for 1 hour. Reaction was performed. Thereafter, water was added to bring the liquid volume to about 350 parts, followed by filtration to remove undissolved substances. After adding water to the obtained mother liquor to make the liquid volume 400 parts, concentrated hydrochloric acid was added while maintaining the liquid temperature at 55 ± 2 ° C. to adjust the pH of the liquid to 3. Next, 40 parts of sodium chloride was added to this liquid over 15 minutes, stirred for 30 minutes, and concentrated hydrochloric acid was added to adjust the pH of the liquid to 2. The obtained acidic aqueous solution was stirred for 1 hour, the precipitated crystals were collected by filtration, and the obtained crystals were washed with 100 parts of a 20% aqueous sodium chloride solution to obtain a red wet solution containing the exemplified compound [M2]. I got a cake.

  (G) The wet cake obtained above was added to 500 parts of methanol, the temperature was raised to 60 to 65 ° C., and the mixture was stirred for 1 hour. The precipitated crystals were collected by filtration, washed with methanol, and dried to obtain the exemplified compound [M2] in the form of a free acid.

(Exemplary compound [Y1])
Exemplified compound [Y1] was synthesized according to the following procedures (A) to (C).

(A) Synthesis of Compound of Formula (21) 17.3 parts of 3-aminobenzenesulfonic acid was dissolved in 200 parts of water while adjusting the pH to 6 with sodium hydroxide, and then 7.2 parts of sodium nitrite was added. . This solution was adjusted to a temperature of 0 to 10 ° C. and dropped into 300 parts of 5% hydrochloric acid over 30 minutes, followed by stirring at 10 ° C. or lower for 1 hour to carry out a diazotization reaction to prepare a diazonium salt.

  In addition, 12.3 parts of 2-methoxyaniline was dissolved in 130 parts of water while adjusting the pH to 5 with sodium hydroxide, and was usually used with 10.4 parts of sodium bisulfite and 8.6 parts of 35% formalin. The methyl-ω-sulfonic acid derivative was obtained by the method. The obtained methyl-ω-sulfonic acid derivative was added to the previously prepared diazonium salt, and the mixture was stirred at a temperature of 0 to 15 ° C. and a pH of 2 to 4 for 5 hours. The resulting reaction solution was adjusted to pH 11 with sodium hydroxide and then stirred at a temperature of 80 to 95 ° C. for 5 hours while maintaining the pH at 11. To this, 100 parts of sodium chloride was added for salting out, and the precipitated solid was collected by filtration to obtain 100 parts of a compound of the following formula (21) as a wet cake.

(B) Synthesis of Compound of Formula (22) 17.3 parts of 3-aminobenzenesulfonic acid was dissolved in 200 parts of water while adjusting the pH to 6 with sodium hydroxide, and then 7.2 parts of sodium nitrite was added. This solution was adjusted to a temperature of 0 to 10 ° C. and dropped into 300 parts of 5% hydrochloric acid over 30 minutes, followed by stirring at 10 ° C. or lower for 1 hour to carry out a diazotization reaction to prepare a diazonium salt.

  Also, 23.1 parts of 2-sulfopropoxyaniline was dissolved in 130 parts of water while adjusting the pH to 5 with sodium hydroxide, and 10.4 parts of sodium bisulfite and 8.6 parts of 35% formalin were used. A methyl-ω-sulfonic acid derivative was obtained by a conventional method. The obtained methyl-ω-sulfonic acid derivative was added to the previously prepared diazonium salt, and the mixture was stirred at a temperature of 0 to 15 ° C. and a pH of 2 to 4 for 5 hours. The resulting reaction solution was adjusted to pH 11 with sodium hydroxide and then stirred at a temperature of 80 to 95 ° C. for 5 hours while maintaining the pH at 11. To this, 100 parts of sodium chloride was added for salting out, and the precipitated solid was collected by filtration to obtain 130 parts of a compound of the following formula (22) as a wet cake.

(C) Synthesis of Exemplified Compound [Y1] and Measurement of Characteristic Values Next, 0.10 parts of Leocol TD90 (trade name; manufactured by Lion, surfactant) was added to 250 parts of ice water and stirred vigorously. 8.0 parts of cyanuric chloride was added and stirred at a temperature of 0 to 5 ° C. for 30 minutes to obtain a suspension. The wet cake of 100 parts of the compound of the formula (21) obtained above was dissolved in 200 parts of water, and the suspension obtained above was added dropwise thereto over 30 minutes. Thereafter, the mixture was stirred at a temperature of 0 to 10 ° C. and a pH of 5 to 6 for 6 hours to obtain a solution. Furthermore, a wet cake of 130 parts of the compound of the formula (22) obtained above was dissolved in 300 parts of water and added dropwise to the solution over 30 minutes. Then, it stirred for 6 hours as temperature 25-35 degreeC and pH 6-7, Furthermore, 18.8 parts of taurines were added, and it stirred for 3 hours as temperature 75-80 degreeC and pH 7-9, and obtained the reaction liquid. After the obtained reaction liquid was cooled to a temperature of 20 to 25 ° C., 800 parts of acetone was added to the reaction liquid and stirred at a temperature of 20 to 25 ° C. for 1 hour to precipitate a solid. The precipitated solid was collected by filtration to obtain 95.0 parts of a wet cake. This wet cake was dried with a hot air dryer at a temperature of 80 ° C. to obtain 30.0 parts of Exemplified Compound [Y1] (water-soluble azo compound). The λ _max value of the exemplified compound [Y1] obtained above in water was λ _max = 391 nm.

(Exemplary compound [Y2])
Exemplified compound [Y2] was synthesized according to the method described in JP-A-2006-57076.

<Preparation of ink>
The components shown in Table 2 below were mixed and sufficiently stirred, and then pressure filtration was performed with a membrane filter having a pore size of 0.2 μm to prepare each ink.

<Configuration of ink set>
Each ink set obtained above was used in the combinations shown in Table 3 below to obtain each ink set.

<Evaluation>
Each ink constituting the ink set obtained above was mounted on a modified ink jet recording apparatus PIXUS iP8600 (manufactured by Canon) that discharges ink by the action of thermal energy. Using this ink jet recording apparatus, a recorded matter containing a monochromatic solid image and a composite black solid image on glossy media for ink jet (trade name: Professional Photo Paper PR101; manufactured by Canon Inc.) was prepared. A monochromatic solid image is an image having a reflection density (initial) of 1.0 recorded using black, cyan, magenta, yellow, and gray inks individually. A solid image of composite black is an image having a reflection density (initial) of 1.0, which is recorded by superimposing cyan, magenta, and yellow inks. The reflection density was measured using a spectrophotometer (trade name: Spectrolino; manufactured by Gretag Macbeth).

Using a gas corrosion tester GH-180 (manufactured by Yamazaki Seiki Co., Ltd.), the temperature in the test tank into which ozone, NO _x , and SO ₂ were introduced was 24 ° C. and the relative humidity was 60%. Objects were exposed to these gases for 432 hours. The gas concentrations were ozone: 1.2 ppm, NO _x : 1.25 ppm, SO ₂ : 0.3 ppm, and the gas flow rate was 2 L / min.

  Thereafter, the recorded matter was taken out from the test tank, and the reflection density (after exposure) in the single color solid image and the fading color balance in the solid black solid image were evaluated as follows.

(Density remaining rate in solid monochrome images)
From the value of the reflection density (initial) and the value of the reflection density (after exposure), the value of the density residual rate was obtained based on the following formula, and the density residual rate in a solid monochrome image was evaluated. The evaluation criteria are as follows. The results are shown in Table 4.

[Evaluation criteria for density residual ratio in solid monochrome images]
A: Concentration residual ratio was 70% or more for all inks constituting the ink set. B: Concentration residual ratio for some inks constituting the ink set was less than 70%.

(Navy blue color balance)
With respect to the solid black images before and after the gas exposure, spectral sensitivity characteristics; reflection density of yellow component, magenta component, and cyan component defined by ISO status A were determined. Specifically, the concentration residual ratio of each component is the same as described above from the reflection density in each wavelength region of cyan, magenta, and yellow measured using a spectrophotometer (trade name: Spectrolino; manufactured by Gretag Macbeth). Based on the formula of The difference between the maximum and minimum density residual ratios of the yellow component, magenta component, and cyan component obtained in this way was set as a ΔOD value, and the amber color balance was evaluated from this ΔOD value. The evaluation criteria are as follows. The results are shown in Table 4. When the ΔOD value is increased, the hue is greatly shifted to any one of the yellow component, cyan component, and magenta component, and the dark blue color balance is decreased.

[Evaluation criteria for dark blue color balance]
A: ΔOD value was less than 10 B: ΔOD value was 10 or more and less than 15 C: ΔOD value was 15 or more.

It is a perspective view of an inkjet recording device. It is a perspective view of the mechanism part of an inkjet recording device. It is sectional drawing of an inkjet recording device. FIG. 6 is a perspective view illustrating a state where an ink cartridge is mounted on the head cartridge. It is a disassembled perspective view of a head cartridge. FIG. 6 is a front view showing a recording element substrate in the head cartridge.

Explanation of symbols

M2041 Separation roller M2060 Paper feed tray M2080 Paper feed roller M3000 Pinch roller holder M3030 Paper guide flapper M3040 Platen M3060 Transport roller M3070 Pinch roller M3110 Paper discharge roller M3120 Spur M3160 Paper discharge tray M4000 Carriage M5000 Pump M0 Electric substrate H1000 Head cartridge H1001 Recording head H1100 First recording element substrate H1101 Second recording element substrate H1200 First plate H1201 Ink supply port H1300 Electric wiring substrate H1301 External signal input terminal H1400 Second plate H1500 Cartridge holder H1501 Ink Flow path H16 0 flow path forming member H1700 filter H1800 seal rubber H1900 ink cartridge H2000 yellow nozzle row H2100 magenta nozzle row H2200 cyan nozzle row H2300 light cyan nozzle row H2400 black nozzle row H2500 gray nozzle row H2600 light magenta nozzle row

Claims (9)

An ink set for inkjet including at least black ink, cyan ink, magenta ink, and yellow ink,
The black ink includes at least a compound represented by the following general formula (I) as the first color material, a compound represented by the following general formula (II) as the second color material, and the following as the third color material: The compound represented by the general formula (III) is contained, and the content (mass%) of the first color material in the black ink is the sum (mass%) of the contents of all the color materials in the black ink. ) To 45.0% to 75.0%, and the content (% by mass) of the second color material in the black ink is equal to the content of all the color materials in the black ink. Greater than 12.0% and less than or equal to 40.0% with respect to total (mass%),

(In general formula (I), A is an optionally substituted aromatic group or heterocyclic group, B is any group represented by the following general formulas (1) to (5), M Are each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In the general formulas (1) to (5), R _{1 to} R ₉ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, carboxyl group, carbamoyl group, alkoxycarbonyl group, Aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxyl group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, Amino group including anilino group and heterocyclic amino group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group , Nitro group, An alkyl or arylsulfonyl group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, a sulfamoyl group, or a sulfonic acid group, and each group is further substituted May be.)

(In the general formula (II), each R ₁₀ is independently a hydrogen atom, a hydroxyl group, a carboxyl group, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms which may be substituted by an alkoxy group having 1 to 4 carbon atoms. 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms Substituted by 4 alkylamino groups, carboxyl-alkylamino groups having 1 to 5 carbon atoms, bis- [carboxy-alkyl having 1 to 5 carbon atoms] amino groups, hydroxyl groups or alkoxy groups having 1 to 4 carbon atoms. C1-C4 alkanoylamino group, carboxyl group or sulfonic acid A phenylamino group, a sulfonic acid group, a halogen atom, or a ureido group which may be substituted with a group or an amino group, [C] is an aliphatic amine residue having a carboxyl group or a sulfonic acid group, and M is Each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In General Formula (III), D is a phenyl group having a substituent, and the substituent includes a carboxyl group, a sulfonic acid group, a chlorine atom, a cyano group, a nitro group, a sulfamoyl group, and a carbon number of 1 to 4. An alkyl group, an alkoxy group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, or a carboxyl group), and an alkylsulfonyl group having 1 to 4 carbon atoms; Selected from the group consisting of (which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group) E and F are each independently a paraphenylene group having a substituent, and the substituent is a carboxyl group Group, sulfonic acid group, alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms (hydroxyl group, alkoxy group having 1 to 4 carbon atoms, sulfo group) Selected from the group consisting of an acid group or a carboxyl group, and an alkylsulfonyl group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group). R ₁₁ is any one of an alkyl group having 1 to 4 carbon atoms which may be substituted with a carboxyl group, a phenyl group which may be substituted with a sulfonic acid group, or a carboxyl group, and R ₁₂ is a cyano group. A group, a carbamoyl group, or a carboxyl group, and R ₁₃ and R ₁₄ are each independently a hydrogen atom, a methyl group, a chlorine atom, or a sulfonic acid group.)
The cyan ink contains at least a compound represented by the following general formula (IV) as the first color material and a compound represented by the following general formula (V) as the second color material, The content (mass%) of the first color material is 1.25 times or more and 5.0 by mass ratio with respect to the content (mass%) of the second color material in the cyan ink. Less than or equal to

(In general formula (IV), A, B, C, and D are each independently a six-membered aromatic ring, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. , E is an alkylene group, and X is a sulfo-substituted anilino group, a carboxyl-substituted anilino group, or a phosphono-substituted anilino group, and the substituted anilino group further includes a sulfonic acid group, a carboxyl group, a phosphono group, and a sulfamoyl group. Carbamoyl group, hydroxyl group, alkoxy group, amino group, alkylamino group, dialkylamino group, arylamino group, diarylamino group, acetylamino group, ureido group, alkyl group, nitro group, cyano group, halogen, alkylsulfonyl group, And at least one substituent selected from the group consisting of an alkylthio group and 1 to 4 Y is a hydroxyl group or an amino group, and l (el), m, and n are 0 ≦ l (el) ≦ 2, 0 ≦ m ≦ 3, and 0.1 ≦ n ≦ 3. And l (el) + m + n = 1 to 4.)

(In the general formula (V), X ₁ , X ₂ , X ₃ and X ₄ are each independently —SO—Z, —SO ₂ —Z, —SO ₂ NR ₁ R ₂ , a sulfonic acid group, —CONR. ₁ R ₂ or CO ₂ R ₁ , where Z is independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, substituted or unsubstituted An aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, wherein R ₁ and R ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted group, A cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. And, in the general formula _{(V), Y 1, Y} 2, Y 3, Y 4, Y 5, Y 6, Y 7, and _{Y 8} are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted Alkyl group, substituted or unsubstituted aryl group, cyano group, substituted or unsubstituted alkoxy group, amide group, ureido group, sulfonamido group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted sulfamoyl group, substituted or An unsubstituted alkoxycarbonyl group, a carboxyl group, or a sulfonic acid group, and a1, a2, a3, and a4 represent the number of substituents of X ₁ , X ₂ , X ₃ , and X ₄ , respectively, 1 is an integer of 1 or 2.
The magenta ink contains at least a compound represented by the following general formula (VI) as the first color material and a compound represented by the following general formula (VII) as the second color material. The content (mass%) of the first color material is 2.5 times or more 10.0 by mass ratio with respect to the content (mass%) of the second color material in the magenta ink. Less than or equal to

(In the general formula (VI), each R is independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a cyclohexyl group, or a mono- or dialkylaminoalkyl group, and each M is independently a hydrogen atom, an alkali metal, or ammonium. Or an organic ammonium, and X is a linking group.)

(In General Formula (VII), R ₂ , R ₃ , R ₄ , and R ₅ are each independently an alkyl group, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. )
The yellow ink contains at least a compound represented by the following general formula (VIII) as a first color material and a compound represented by the following general formula (IX) as a second color material, The content (% by mass) of the first color material is 1.0 times or more and 10.0 by mass ratio with respect to the content (% by mass) of the second color material in the yellow ink. Less than or equal to

(In General Formula (VIII), R ₁ , R ₂ , Y ₁ and Y ₂ are each independently a monovalent group, and X ₁ and X ₂ are each independently having a Hammett's σp value of 0.20 or more. Z ₁ and Z ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted group An aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, and M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

(In General Formula (IX), R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a sulfonic acid group, n is 1 or 2, and m is 1 to 3) X is an integer of 2 to 4, y is an integer of 1 to 3, and M is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)
An ink set characterized by that. The ink set further includes a gray ink;
The gray ink is at least a compound represented by the general formula (IV) as a first color material, a compound represented by the general formula (VIII) as a second color material, and the general color as a third color material. The ink set according to claim 1, comprising a compound represented by the formula (VII) and a compound represented by the general formula (I) as a fourth coloring material.   The ink set according to claim 1 or 2, wherein the cyan ink includes two types of cyan inks having different color material contents.   The ink set according to any one of claims 1 to 3, wherein the magenta ink includes two types of magenta inks having different color material contents. An inkjet recording method for recording on a recording medium by discharging ink by an inkjet method,
An ink jet recording method comprising using the ink constituting the ink set according to any one of claims 1 to 4 as the ink.   The inkjet recording method according to claim 5, wherein the inkjet system is a system that ejects ink by the action of thermal energy. An ink cartridge including an ink storage portion for storing ink,
5. The ink cartridge according to claim 1, wherein the ink stored in the ink storage portion is any of the inks constituting the ink set according to claim 1. A recording unit comprising an ink containing portion for containing ink and a recording head for discharging ink,
5. The recording unit according to claim 1, wherein the ink stored in the ink storage portion is any one of the inks constituting the ink set according to claim 1. An ink jet recording apparatus comprising an ink containing portion for containing ink and a recording head for discharging ink,
5. The ink jet recording apparatus according to claim 1, wherein the ink stored in the ink storage unit is any one of the inks constituting the ink set according to claim 1.

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