JP4632459B2 - Ink, ink jet recording method, ink cartridge, recording unit, and ink jet recording apparatus - Google Patents

Description

  The present invention relates to an ink, an ink jet recording method, an ink cartridge, a recording unit, and an ink jet recording apparatus.

  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. Moreover, in addition to the progress of high image quality of images obtained by the ink jet recording method, with the rapid spread of digital cameras, it has become widely used as an image output method comparable to silver salt photography.

  One of the problems of the ink jet recording method is image storability of the obtained recorded matter. In general, a recorded matter obtained by the ink jet recording method has a problem that its image storage stability is inferior to that of a silver salt photograph. More specifically, when the recorded material is exposed to light, humidity, heat, or environmental gas present in the air for a long time, the coloring material on the recorded material deteriorates, and the color tone of the image changes. There is a problem that fading is likely to occur. Light resistance in images formed with black ink is often accompanied by a change in color tone due to deterioration of the color material, and since deterioration is particularly noticeable, it has been regarded as a problem to be solved in the past, and many proposals have been made. ing.

  For example, proposals have been made regarding the suppression of colorant deterioration by adding additives such as ultraviolet absorbers and antioxidants to the ink. However, in order to obtain a sufficient effect by using these additives, it is necessary to increase the content of the additive, which may affect the reliability of the ink, such as ink ejection failure and fixation. There is sex.

  In response to such problems, various proposals have been made for improving the light resistance of an image by using an ink containing a color material having a structure excellent in light resistance. For example, with an ink containing a dye that defines the number of aromatic conjugated π electrons that are not directly bonded to an azo group, image fastness such as light resistance and ozone resistance, ink storage stability, and image There is a proposal to make the color tone of the above excellent (see Patent Document 1). In addition, there are proposals relating to yellow to red dyes which are excellent in color tone of images and are useful as toning dyes for black inks and which are excellent in light resistance and ozone resistance, and inks containing the dyes (patents) Reference 2).

On the other hand, from the viewpoint of image quality, an image formed using black ink is required to have a color tone close to neutral in addition to high optical density. The neutral color tone in the present invention specifically refers to the color tone of an image by measuring a ^* and b ^* in an L ^* a ^* b ^* display system defined by the CIE (International Commission on Illumination). Means that an image has these values within a specific range. This will be described in detail in the examples described later. In order to obtain a color tone close to neutral, it is necessary for the image to exhibit near-flat absorption in the visible region. On the other hand, with an azo dye generally used as a water-soluble dye, it is difficult to achieve a high optical density and a color tone close to neutral with one color material. For this reason, the technique regarding achieving the above-mentioned request | requirement by combining several different dye is proposed.

  For example, C.I. I. There has been a proposal relating to giving an image excellent in light fastness by using an ink containing both a specific black dye having a bluish color such as Food Black 1 and magenta and / or yellow dye (Patent Document 3). reference). There is also a proposal for a black ink containing both a tetrakisazo dye and a condensation compound of 4,4'-dinitrostilbene-2,2'-disulfonic acid and aminobenzene. That is, by setting it as such a composition, it is supposed that the image excellent in light resistance and ozone resistance can be formed (refer patent document 4). A black ink containing both a specific azo dye having a heterocyclic ring and an azo dye having a specific structure has been proposed (see Patent Document 5). Further, there has been proposed a black ink whose absorption maximum wavelength in the absorption spectrum includes both a dye having a specific structure existing in the long wavelength region and a dye existing in the short wavelength region (see Patent Document 6). These inks are supposed to give images excellent in color tone, light resistance and ozone resistance.

  Further, the following proposal has been made regarding obtaining a gray image using black ink. That is, there is a proposal relating to an ink that defines an absorption maximum wavelength in an absorption spectrum of a colorant and has both a dye having a maximum absorption wavelength in a long wavelength region and a dye having a maximum absorption wavelength in a short wavelength region (Patent Document 7). reference). And by using the ink containing these dyes, a black ink having excellent light resistance can be obtained by keeping the color tone in the gray image achromatic and defining the color difference after the light resistance test. It is disclosed.

In addition, the following proposal has been proposed to suppress deterioration due to humidity with respect to a gray or black image formed using a toned ink containing black, yellow, magenta, and cyan dyes. is there. That is, it has been proposed to use an ink containing a black dye and an appropriate color dye, and an image excellent in light resistance and moisture resistance can be obtained by such ink (see Patent Document 8). Specifically, an image is formed using an ink set of three types of inks of light gray, medium gray, and dark gray having the hue range, saturation range, and lightness (L ^* ) characteristics described below. Form. Light gray ink has a hue range of 250 ° to 310 °, a saturation range of less than 6, and a lightness (L ^* ) range of 54 to 72. The medium gray ink has a hue range of 250 ° to 310 °, a saturation range of less than 6, and a lightness (L ^* ) range of 30 to 47. Further, the dark gray ink has a hue range of 150 ° to 270 °, a saturation range of less than 6, and a lightness (L ^* ) range of 10 to 18. When two or three inks of light gray, medium gray, and dark gray are recorded together, the gray color has a hue range of 250 ° to 310 ° and a saturation range of 2 to 6. Is described.

JP 2005-139427 A International Publication No. 2006/001274 Pamphlet Japanese Patent Publication No. 8-026263 JP-A-2005-068416 JP 2005-146244 A JP 2006-28295 A JP 2006-028256 A JP 2006-526062 A

  Furthermore, the present inventors have examined an image formed using black ink from the viewpoint of its color tone and light resistance. In an image formed with a recording duty of 100%, the following general formula (I) It came to pay attention that the compound represented by this is excellent in light resistance.

  Many of the known black dyes tend to change the color tone of the image to yellow after a light fastness test in which the image is irradiated with light. That is, an image formed using an ink containing a known black dye tends to have a greater degree of decrease in optical density in the magenta wavelength region, particularly in the cyan wavelength region, compared to the optical density in the yellow wavelength region. The optical density in each wavelength region can be obtained by measuring the optical density of each component of yellow, magenta, and cyan using a spectrophotometer (spectral sensitivity characteristic; using ISO status A). .

  In contrast, an image formed using an ink containing the compound represented by the general formula (I) has the same degree of decrease in optical density in each of the yellow, magenta, and cyan wavelength regions. I understood. That is, it was found that the compound represented by the general formula (I) has a characteristic that the color tone (color tone) does not easily change with respect to the light resistance test. Furthermore, the color tone of the image formed using the ink containing the compound represented by the general formula (I) is greenish black, and it has been found that the image may be applicable to black ink.

  Therefore, the present inventors used a compound represented by the general formula (I) in combination with a compound represented by the general formula (II) having a yellow to red color tone and excellent light resistance. Studies were made on adjusting the color tone of the ink containing the compound represented by formula (I). The compound represented by the general formula (II) will be described later. As a result, the color tone of the initial image formed with ink containing these compounds at a recording duty of 100% was close to neutral. Further, the residual ratio of the optical density of black (spectral sensitivity characteristics; using ISO Visual) after the light resistance test of the image was within the expected range.

  However, it has been found that the ink having both the compound represented by the general formula (I) and the compound represented by the general formula (II) has the following new problems. That is, an image formed using such an ink has a large change in color tone after the light resistance test. Specifically, even though the ink contains the compound represented by the general formula (I) having the characteristic that the color tone of the image after the light resistance test hardly changes, the image is in the yellow wavelength region. The degree of decrease in the optical density in the magenta and cyan wavelength regions was larger than that in FIG. That is, in the ink having both the compound represented by the general formula (I) and the compound represented by the general formula (II), a part of the characteristics of the compound represented by the general formula (I) in the recording medium. As a result, it was found that the excellent light resistance of this compound was not fully exhibited.

  Accordingly, a first object of the present invention is to solve the above-described problems in an ink containing a compound represented by general formula (I) and a compound represented by general formula (II). That is, it is an object to provide an ink that not only has an initial color tone close to neutral, but also has an excellent balance of color tone changes after the light resistance test.

  In addition, during the study of the solution to the first problem, the inventors of the present invention have found that the ink-receiving layer is formed when the ink is applied to the recording medium due to the difference in the structure of the color material contained in the ink. The knowledge that the distribution position (penetration depth) of the coloring material in the thickness direction may be different was obtained. That is, an image formed with ink containing a plurality of color materials has the following problems. That is, the degree of deterioration of each color material due to light varies depending on the position (penetration depth) of each color material in the thickness direction of the ink receiving layer of the recording medium. As a result, it was found that the color tone of the image after the light resistance test is different and the balance of the color tone change may be impaired.

  Therefore, the second problem of the present invention is to control the distribution position (penetration depth) in the thickness direction of the ink receiving layer of the recording medium by optimizing the selection conditions of the color material when using a plurality of color materials. And providing a technique for finding an effective correlation for light resistance. Furthermore, it is providing the ink using this technique.

Furthermore, the present inventors have gradation properties using an ink containing a compound represented by the general formula (I) and a compound represented by the general formula (II) in the course of studying the above-described problems. It has been found that when an image is formed, the color tone of the obtained image may deviate from neutral. When an image having a gradation property (gray image) is formed using black ink, a change in color tone tends to be noticeable in an image near a recording duty of 40%, which is so-called halftone (see FIG. 7). . FIG. 7 is a chromaticity diagram on the a ^* b ^* plane in an image formed using black ink at a recording duty of 100%, 80%, 60%, 40%, 20%, and 10%. In the present invention, the “image having gradation” means an image formed by changing the recording duty to at least two points from an image having a high recording duty to an image having a low recording duty when forming the image. Say it.

  Accordingly, a third problem of the present invention is to provide an ink in which the tone balance is optimized and the tone balance is optimized even when an image having gray scale (gray image) is formed.

  An object of the present invention is to solve at least one problem described above. Specifically, to provide a black ink that gives an image with excellent light fastness, in which the initial color tone is close to neutral, there is little change in color tone even after the light fastness test, and the change balance is excellent. It is in. Another object of the present invention is to provide a black ink that can reduce a change in color tone of an image even when an image having gradation is formed. 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 the ink.

（一般式（Ｉ）中、Ａは置換されていてもよいナフチル基であり、Ｂは下記一般式（２）で表される基であり、Ｍはそれぞれ独立に、水素原子、アルカリ金属、アンモニウム、又は有機アンモニウムである。）

（一般式（２）中、Ｒ ₃ は、水素原子、ハロゲン原子、脂肪族基、芳香族基、複素環基、カルボキシル基、カルバモイル基、アルコキシカルボニル基、アリールオキシカルボニル基、複素環オキシカルボニル基、アシル基、ヒドロキシル基、アルコキシ基、アリールオキシ基、複素環オキシ基、シリルオキシ基、アシルオキシ基、カルバモイルオキシ基、アルコキシカルボニルオキシ基、アリールオキシカルボニルオキシ基、アニリノ基及び複素環アミノ基を含むアミノ基、アシルアミノ基、ウレイド基、スルファモイルアミノ基、アルコキシカルボニルアミノ基、アリールオキシカルボニルアミノ基、アルキル若しくはアリールスルホニルアミノ基、複素環スルホニルアミノ基、シアノ基、ニトロ基、アルキル若しくはアリールチオ基、複素環チオ基、アルキル若しくはアリールスルホニル基、複素環スルホニル基、アルキル若しくはアリールスルフィニル基、複素環スルフィニル基、スルファモイル基、又はスルホン酸基であり、各基はさらに置換されていてもよい。）

（一般式（II）中、Ｒ₁₀はそれぞれ独立に、水素原子、ヒドロキシル基、カルボキシル基、ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルキル基、ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルコキシル基、ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルキルアミノ基、カルボキシル−炭素数１乃至５のアルキルアミノ基、ビス−〔カルボキシ−炭素数１乃至５のアルキル〕アミノ基、ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルカノイルアミノ基、カルボキシル基若しくはスルホン酸基若しくはアミノ基で置換されていてもよいフェニルアミノ基、スルホン酸基、ハロゲン原子、又はウレイド基であり、［Ｃ］はカルボキシル基又はスルホン酸基を有する脂肪族アミン残基であり、Ｍはそれぞれ独立に、水素原子、アルカリ金属、アンモニウム、又は有機アンモニウムである。）

（一般式（III）中、Ｄは、置換基を有するフェニル基であり、該置換基は、カルボキシル基、スルホン酸基、塩素原子、シアノ基、ニトロ基、スルファモイル基、炭素数１乃至４のアルキル基、炭素数１乃至４のアルコキシ基（ヒドロキシル基、炭素数１乃至４のアルコキシ基、スルホン酸基、又はカルボキシル基で置換されていてもよい）、及び炭素数１乃至４のアルキルスルホニル基（ヒドロキシル基、スルホン酸基、又はカルボキシル基で置換されていてもよい）からなる群から選ばれる。Ｅ及びＦはそれぞれ独立に、置換基を有するパラフェニレン基であり、該置換基は、カルボキシル基、スルホン酸基、炭素数１乃至４のアルキル基、炭素数１乃至４のアルコキシ基（ヒドロキシル基、炭素数１乃至４のアルコキシ基、スルホン酸基、又はカルボキシル基で置換されていてもよい）、及び炭素数１乃至４のアルキルスルホニル基（ヒドロキシル基、スルホン酸基、又はカルボキシル基で置換されていてもよい）からなる群から選ばれる。Ｒ₁₁は、カルボキシル基で置換されていてもよい炭素数１乃至４のアルキル基、スルホン酸基で置換されていてもよいフェニル基、又はカルボキシル基のいずれかであり、Ｒ₁₂は、シアノ基、カルバモイル基、又はカルボキシル基のいずれかであり、Ｒ₁₃及びＲ₁₄はそれぞれ独立に、水素原子、メチル基、塩素原子、又はスルホン酸基のいずれかである。） The above object is achieved by the present invention described below. That is, the ink according to the present invention is an ink containing at least a first color material, a second color material, and a third color material, and the first color material has the following general formula. A compound represented by (I), wherein the second colorant is a compound represented by the following general formula (II), and the third colorant is represented by the following general formula (III): It is characterized by being a compound.

(In the general formula (I), A is an optionally substituted naphthyl group, B is is Ru group represented by the following general formula (2), M is each independently a hydrogen atom, an alkali metal, ammonium Or organic ammonium.)

(In general formula ( 2 ), R ₃ represents a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a heterocyclic group, a carboxyl group, a carbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, or a heterocyclic oxycarbonyl group. Amino including acyl group, hydroxyl group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, anilino group and heterocyclic amino group Group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group, nitro group, alkyl or arylthio group, compound And a cyclic thio 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 may be further substituted.

(In the general formula (II), each R ₁₀ independently represents 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 group Or a phenylamino group optionally substituted with an amino group, a sulfonic acid group, a halogen atom, or a ureido 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 the general formula (III), D is a phenyl group having a substituent, and the substituent is a carboxyl group, a sulfonic acid group, a chlorine atom, a cyano group, a nitro group, a sulfamoyl group, or a group having 1 to 4 carbon atoms. 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, sulfonic acid , Or carboxyl which may be substituted with a group), and an alkylsulfonyl group (hydroxyl group of 1 to 4 carbon atoms, selected from the group consisting of a sulfonic acid group, or may be substituted by carboxyl group) .R ₁₁ is any 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, It is either 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.)

  An ink jet recording method according to another embodiment of the present invention is an ink jet recording method in which ink is ejected by an ink jet method to perform recording on a recording medium, wherein the ink is an ink having the above-described configuration. .

  An ink cartridge according to another embodiment of the present invention is an ink cartridge including an ink storage portion that stores ink, wherein the ink is ink having the above-described configuration.

  According to another embodiment of the present invention, there is provided a recording unit comprising an ink storage portion for storing ink and a recording head for discharging ink, wherein the ink is ink having the above-described configuration. It is characterized by that.

  An ink jet recording apparatus according to another embodiment of the present invention is an ink jet recording apparatus including an ink containing portion for containing ink and a recording head for ejecting ink. It is characterized by being.

  According to the present invention, there is provided a black ink that not only has an initial color tone close to neutral, but also provides an image with an excellent balance of color tone changes after a light resistance test. In addition, according to the present invention, it is possible to provide black ink that can reduce a change in color tone of an image even when an image having gradation is formed. Furthermore, according to another embodiment of the present invention, an ink jet recording method using ink, an ink cartridge, a recording unit, and an ink jet recording apparatus can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail.
In the present invention, when the compound is a salt, the salt is dissociated into ions in the ink, but is expressed as “contains a salt” for convenience. In the following description, the compound represented by the general formula (I), the compound represented by the general formula (II), and the compound represented by the general formula (III) “Compound”, “compound of general formula (II)”, “compound of general formula (III)”.

  In the process of studying the color tone and light resistance of an image obtained using an ink containing the compound of the general formula (I) and the compound of the general formula (II), which will be described later, Thus, attention has been paid to the compound of the general formula (III) described later. According to the study by the present inventors, an image obtained using an ink containing only the compound of the general formula (III) has a bluish color tone. Further, the degree of decrease in optical density in each wavelength region after the light resistance test of an image formed with an ink containing only the compound of general formula (III) is in the order of yellow wavelength region, magenta wavelength region, and cyan wavelength region. Although it increases, it was found that the residual ratio of optical density is high.

  Accordingly, the present inventors have described in detail the ink containing the compound of the general formula (I) and the compound of the general formula (II) as the coloring material, and further the compound of the general formula (III) in addition to these. The examination was done. As a result, the color tone of an image (initial image) formed using inks containing these three color materials with a recording duty of 100% was close to neutral. In addition, the image has the same degree of decrease in optical density in the yellow, magenta, and cyan wavelength regions with respect to light resistance, and has a small color change after the light resistance test, and has a color tone close to neutral. I found it to keep the image. The present invention has been made based on such findings.

  Furthermore, the present inventors examined the ratio of the content of the compound of general formula (I), the compound of general formula (II), and the compound of general formula (III) in the ink. As a result, by setting the mass ratio of the contents of these three color materials within a certain range, not only an image with a recording duty of 100% but also an image having gradation can have a color tone close to neutral. It turns out that an image is obtained. Furthermore, it was found that an image obtained with an ink having this mass ratio within a certain range is an image having a smaller color tone change after the light resistance test and having a color tone closer to neutral with respect to light resistance.

  The ink of the present invention is characterized by containing at least a compound of the general formula (I), a compound of the general formula (II), and a compound of the general formula (III). Regarding the reason for the effect that the color tone change after the light resistance test is suppressed and the balance of the color tone change is good in an image formed with an ink containing a combination of these three compounds (color materials), the present inventors. Thinks as follows.

  When using a recording medium that adsorbs the coloring material to the fine particles forming the porous structure of the ink receiving layer as the recording medium, the distribution position (penetration depth) of the coloring material in the thickness direction of the ink receiving layer of the recording medium is: It depends on the cohesiveness of the color material and the adsorptivity to the recording medium. In this case, it is considered that the degree of deterioration of the color material by the light resistance test varies depending on the depth of penetration of the color material into the recording medium. First, when the color material is present at a deeper position (more inside) in the thickness direction of the recording medium, the light intensity is scattered or absorbed in the recording medium, so that the light intensity is increased in that portion. The color material is considered to be hardly affected by light because it falls. On the other hand, when the color material is present at a shallower position (more near the surface) in the thickness direction of the recording medium, it is likely to be affected by light, and the color material is likely to be deteriorated by a light resistance test. .

  Based on this assumption, the present inventors confirmed using the inks of Examples and Comparative Examples described later, and found the following. First, as a result of performing image formation using each ink containing each compound (coloring material) constituting the ink of the present invention alone, the thickness of the recording material, that is, the thickness of the ink receiving layer of the recording medium. It was found that the distribution position of the color material in the direction differs depending on each color material. FIGS. 8A to 8C are schematic views showing the distribution positions of the color materials in the recording medium when inks containing the color materials used in the present invention are applied to the recording medium. Hereinafter, the relationship between the color material distribution position on the recording medium and the light resistance of the image will be described with reference to FIG. As shown in FIG. 8, when the ink containing only the compound of the general formula (I) is used, the overall distribution position of the color material is the shallowest (more distributed near the surface of the recording medium). Next, the overall distribution position of the color material when the ink containing only the compound of the general formula (III) is used is the entire distribution position of the color material when the ink containing only the compound of the general formula (I) is used. It became deeper than the typical distribution position. Next, when the ink containing only the compound of the general formula (II) was used, the overall distribution position of the coloring material became deepest among these (more distributed inside the recording medium).

  As a result, in the recording medium provided with ink, the distribution position in which the compound of the general formula (I), which has excellent light resistance and hardly changes in color tone, is most susceptible to deterioration of the color material by light. It shows that there is. The reason why the change in color tone after the light resistance test of the image formed using the ink of the general formula (I) in combination with the compound of the general formula (II) is large is as follows. It is believed that there is. First, since the compound of the general formula (I) has high cohesiveness, it does not easily penetrate in the thickness direction of the recording medium and is distributed near the surface of the recording medium, while the compound of the general formula (II) has permeability. Is large, it easily penetrates in the direction of the thickness of the recording medium, and is distributed more inside the recording medium. Therefore, the compound of the general formula (I) is more susceptible to light degradation than the compound of the general formula (II), and maintains the balance of the color tone inherent to the compound of the general formula (I). Is estimated to be insufficient.

  On the other hand, the image formed with the ink of the present invention containing three kinds of compounds (coloring materials) shown in FIG. 8 (e) is in the wavelength regions of yellow, magenta and cyan after the light resistance test. It was found that the decrease in the optical density was almost the same, and the color tone change of the image was small. The reason why the color tone change of the image can be suppressed by the ink containing the three kinds of compounds as described above is considered as follows. That is, the compound of general formula (I), the compound of general formula (II), and the compound of general formula (III) contained in the ink are present in a relatively uniform state in the recording medium. As a result, in the case of the ink using the above three kinds of coloring materials in combination with the compound of the general formula (I) and the compound of the general formula (II), It is presumed that deterioration due to light can be further suppressed, and furthermore, each color material has been faded in a balanced manner.

  The inventors of the present invention include an ink containing two compounds represented by general formulas (I) and (II), and three compounds represented by general formulas (I), (II) and (III). The above matters were examined in more detail by forming an image with each of the inks containing. Specifically, the distribution positions (penetration depths) of the color materials in the thickness direction of the ink receiving layer of the recording medium in these images were compared. As a result, as shown in FIG. 8 (e), when the latter ink containing three kinds of compounds was applied to the recording medium, the former contained two kinds of compounds shown in FIG. 8 (d). Compared to the case where the ink to be applied is applied, the whole color material tends to be distributed at the same or shallow position. This is because, in the latter ink, the three types of compounds interact in the recording medium, so that aggregation of the compound of the general formula (I) in the recording medium is suppressed, and This is presumably because the penetration of the compound of formula (II) is also suppressed.

  Regarding the reason why such a phenomenon occurs, the present inventors infer that the following may be the cause. First, when the structures of the compound of the general formula (I), the compound of the general formula (II), and the compound of the general formula (III) used in the present invention are compared, they have the following characteristics. The compound of general formula (I) is a disazo compound having at least two heterocyclic rings. The compound of the general formula (II) is a tetrakisazo compound having six benzene rings and one heterocyclic ring. On the other hand, the compound of the general formula (III) is a compound having three benzene rings and one heterocyclic ring. These compounds are schematically represented as follows (J represents a benzene ring, J 'represents an aromatic ring, and K represents a heterocyclic ring).

  Comparing the structures of these compounds, the compound of the general formula (III) has both the structure similar to the compound of the general formula (I) and the structure similar to the compound of the general formula (II). . Therefore, when these compounds coexist in the recording medium, the compound of the general formula (III) is considered to interact with both of the compounds of the general formula (I) and the general formula (II). . This is presumed to suppress the aggregation of the compound of the general formula (I) in the recording medium and the penetration of the compound of the general formula (II) into the recording medium. Furthermore, because the ink contains the compound of the general formula (II), the color tone of the ink can be adjusted to neutral, so that a neutral image can be obtained even in an image having gradation. It is thought that.

As described above, the ink of the present invention contains three kinds of coloring materials, that is, the compound of the general formula (I), the compound of the general formula (II), and the compound of the general formula (III). Features. In the present invention, in particular, a light resistance test is performed on the image formed using the ink, and the residual optical density in each wavelength region obtained from the optical density in the image before the light resistance test and the image after the light resistance test. It is particularly preferable that the rate is designed so as to satisfy the following relationship. The condition for forming the image is that the amount of ink applied to the recording medium is 11 g / m ² (corresponding approximately to a recording duty of 100%). The image thus obtained is subjected to a light resistance test under the condition that the xenon irradiation intensity is 100 kilolux, the temperature is 24 ° C., and the relative humidity is 60% for 100 hours. The spectral sensitivity characteristics in the yellow wavelength region, the magenta wavelength region, and the cyan wavelength region of the image before and after the light resistance test; the yellow component, the magenta component, and the cyan component defined by ISO status A Each optical density is determined. Further, the residual ratio of the optical density represented by the following formula is such that the difference between the maximum value and the minimum value of the residual ratio of the optical density of the yellow component, the magenta component, and the cyan component is 0 or more and 5 or less. Particularly preferred. By setting the ink to satisfy such a condition, a neutral image can be more maintained even in an image after the light resistance test. That is, an image with more excellent light resistance can be obtained. Of course, the present invention is not limited to ink that satisfies the above conditions.

  In the present invention, it is particularly preferable that each color material satisfies the following conditions. Specifically, the compound of general formula (I) as the first color material, the compound of general formula (II) as the second color material, and the compound of general formula (III) as the third color material It is particularly preferred that the types of solubilizing groups in are the same and the number of solubilizing groups in one molecule is the same. The solubilizing group is a group that can be dissociated in the ink, and examples thereof include a sulfonic acid group and a carboxyl group. By making the ink satisfying the above conditions, the structures of the three types of compounds used as the colorant become more similar, and the compounds of the general formula (III) are those of the compounds of the general formulas (I) and (II). It is considered that the effects of interacting with each other were obtained particularly remarkably. Further, with the configuration as described above, the color tone of the ink can be adjusted to be more neutral. Therefore, it is considered that an image having a neutral color tone can be obtained even in an image having gradation.

<Ink>
The ink of the present invention is an ink containing at least the compound of the general formula (I) as the first color material and the compound of the general formula (II) as the second color material. 3 is characterized by containing a color material of the general formula (III). The components constituting the ink according to the present invention and the physical properties of the ink will be described in detail below.

（一般式（Ｉ）中、Ａは置換されていてもよい芳香族基又は複素環基であり、Ｂは下記一般式（１）乃至（５）で表されるいずれかの基であり、Ｍはそれぞれ独立に、水素原子、アルカリ金属、アンモニウム、又は有機アンモニウムである。） (Coloring material)
[First coloring material: compound represented by formula (I)]
The ink of the present invention needs to contain a compound of the following general formula (I) as the first 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.)

（一般式（１）乃至（５）中、Ｒ₁乃至Ｒ₉はそれぞれ独立に、水素原子、ハロゲン原子、脂肪族基、芳香族基、複素環基、カルボキシル基、カルバモイル基、アルコキシカルボニル基、アリールオキシカルボニル基、複素環オキシカルボニル基、アシル基。ヒドロキシル基、アルコキシ基、アリールオキシ基、複素環オキシ基、シリルオキシ基、アシルオキシ基、カルバモイルオキシ基、アルコキシカルボニルオキシ基、アリールオキシカルボニルオキシ基、アニリノ基及び複素環アミノ基を含むアミノ基。アシルアミノ基、ウレイド基、スルファモイルアミノ基、アルコキシカルボニルアミノ基、アリールオキシカルボニルアミノ基、アルキル若しくはアリールスルホニルアミノ基、複素環スルホニルアミノ基、シアノ基、ニトロ基、アルキル若しくはアリールチオ基。複素環チオ基、アルキル若しくはアリールスルホニル基、複素環スルホニル基、アルキル若しくはアリールスルフィニル基、複素環スルフィニル基、スルファモイル基、又はスルホン酸基であり、各基はさらに置換されていてもよい。）

(In the general formulas (1) to (5), R _{1 to} R ₉ are each independently a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a heterocyclic group, a carboxyl group, a carbamoyl group, an 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, An amino group including an anilino group and a heterocyclic amino group: acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group , Nitro group, al Kill or arylthio group, which is a heterocyclic thio 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.)

  A in the general formula (I) is an optionally substituted aromatic group or heterocyclic group, and specifically can be the following substituents. Examples include a benzene ring, naphthalene ring, pyridine ring, imidazole ring, pyrazole ring, thiazole ring, isothiazole ring, thiadiazole ring, benzothiazole ring, and benzoisothiazole ring. Among these, a benzene ring, a naphthalene ring, a pyridine ring, a pyrazole ring, an imidazole ring, an isothiazole ring, or a benzothiazole ring is preferable, and a benzene ring or a naphthalene ring is more preferable.

B in the general formula (I) is any group represented by the general formulas (1) to (5) shown above. R _{1 to} R ₉ in formulas (1) to (5) are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, carboxyl group, carbamoyl group, alkoxycarbonyl group, aryloxy A carbonyl group, a heterocyclic oxycarbonyl group, and an acyl group. An amino group including a hydroxyl group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, a silyloxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an anilino group, and a heterocyclic amino group. Acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group, nitro group, alkyl or arylthio group. A heterocyclic thio 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 may be further substituted.

  Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. Among them, a chlorine atom or a bromine atom is preferable, and a chlorine atom is particularly preferable.

  Aliphatic groups include alkyl groups, substituted alkyl groups, alkenyl groups, substituted alkenyl groups, alkynyl groups, substituted alkynyl groups, aralkyl groups, and substituted aralkyl groups. These aliphatic groups may have a branch or may form a ring. The aliphatic group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms. The aryl moiety of the aralkyl group and substituted aralkyl group is preferably phenyl or naphthyl, more preferably phenyl. Specific examples of the aliphatic group include the following groups. Examples include methyl, ethyl, butyl, isopropyl, t-butyl, hydroxyethyl, methoxyethyl, cyanoethyl, trifluoromethyl, 3-sulfopropyl, 4-sulfobutyl, cyclohexyl, benzyl, 2-phenethyl, vinyl, and allyl.

  Examples of the aromatic group include a monovalent or divalent aryl group and a substituted aryl group. Examples of the monovalent aromatic group include an aryl group and a substituted aryl group. The aryl group is preferably phenyl or naphthyl, and more preferably phenyl. The monovalent aromatic group preferably has 6 to 20 carbon atoms, and more preferably 6 to 16 carbon atoms. Specific examples of the monovalent aromatic group include phenyl, p-phenylphenyl, p-tolyl, p-methoxyphenyl, o-chlorophenyl, p-chlorophenyl, p-acetylaminophenyl, and m- (3- Sulfopropylamino) phenyl. Examples of the divalent aromatic group include those obtained by divalentizing these monovalent aromatic groups. Specific examples include phenylene, p-tolylene, p-methoxyphenylene, o-chlorophenylene, m- (3-sulfopropylamino) phenylene, and naphthylene.

  Examples of the heterocyclic group include a heterocyclic group having a substituent and an unsubstituted heterocyclic group. The heterocyclic ring may be condensed with an aliphatic ring, an aromatic ring, or another heterocyclic ring. The heterocyclic group is preferably a 5-membered or 6-membered heterocyclic group, and examples of the hetero atom of the heterocyclic group include a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples of the substituent include an aliphatic group, a halogen atom, an alkyl or arylsulfonyl group, an acyl group, an acylamino group, a sulfamoyl group, a carbamoyl group, and an ionic hydrophilic group. Examples of the monovalent heterocyclic group include 2-pyridyl group, 3-pyridyl group, 2-thienyl group, 2-thiazolyl group, 2-benzothiazolyl group, 2-benzoxazolyl group, and 2-furyl group. It is done. Examples of the divalent heterocyclic group include groups in which a hydrogen atom in the monovalent heterocyclic group is removed to form a bond.

  Examples of the carbamoyl group include a carbamoyl group having a substituent and an unsubstituted carbamoyl group. Specific examples of the substituent include an alkyl group. Specific examples of the carbamoyl group include a methylcarbamoyl group and a dimethylcarbamoyl group.

  Examples of the alkoxycarbonyl group include an alkoxycarbonyl group having a substituent and an unsubstituted alkoxycarbonyl group. As the alkoxycarbonyl group, an alkoxycarbonyl group having 2 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

  Examples of the aryloxycarbonyl group include a substituted aryloxycarbonyl group and an unsubstituted aryloxycarbonyl group. The aryloxycarbonyl group is preferably an aryloxycarbonyl group having 7 to 20 carbon atoms. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the aryloxycarbonyl group include a phenoxycarbonyl group.

  Examples of the heterocyclic oxycarbonyl group include a substituted heterocyclic oxycarbonyl group and an unsubstituted heterocyclic oxycarbonyl group. As the heterocyclic oxycarbonyl group, a heterocyclic oxycarbonyl group having 2 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the heterocyclic oxycarbonyl group include a 2-pyridyloxycarbonyl group.

  Examples of the acyl group include a substituted acyl group and an unsubstituted acyl group. As the acyl group, an acyl group having 1 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the acyl group include an acetyl group and a benzoyl group.

  Examples of the alkoxy group include a substituted alkoxy group and an unsubstituted alkoxy group. As the alkoxy group, an alkoxy group having 1 to 20 carbon atoms is preferable. Specific examples of the substituent include an alkoxy group, a hydroxyl group, and an ionic hydrophilic group. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a methoxyethoxy group, a hydroxyethoxy group, and a 3-carboxypropoxy group.

  Examples of the aryloxy group include a substituted aryloxy group and an unsubstituted aryloxy group. As the aryloxy group, an aryloxy group having 6 to 20 carbon atoms is preferable. Specific examples of the substituent include an alkoxy group and an ionic hydrophilic group. Specific examples of the aryloxy group include a phenoxy group, a p-methoxyphenoxy group, and an o-methoxyphenoxy group.

  Examples of the heterocyclic oxy group include a heterocyclic oxy group having a substituent and an unsubstituted heterocyclic oxy group. As the heterocyclic oxy group, a heterocyclic oxy group having 2 to 20 carbon atoms is preferable. Specific examples of the substituent include an alkyl group, an alkoxy group, and an ionic hydrophilic group. Specific examples of the heterocyclic oxy group include a 3-pyridyloxy group and a 3-thienyloxy group.

  As the silyloxy group, an aliphatic group having 1 to 20 carbon atoms and a silyloxy group substituted with an aromatic group are preferable. Specific examples of the silyloxy group include trimethylsilyloxy and diphenylmethylsilyloxy.

  Examples of the acyloxy group include a substituted acyloxy group and an unsubstituted acyloxy group. As the acyloxy group, an acyloxy group having 1 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the acyloxy group include an acetoxy group and a benzoyloxy group.

  Examples of the carbamoyloxy group include a carbamoyloxy group having a substituent and an unsubstituted carbamoyloxy group. Specific examples of the substituent include an alkyl group. Specific examples of the carbamoyloxy group include an N-methylcarbamoyloxy group.

  Examples of the alkoxycarbonyloxy group include an alkoxycarbonyloxy group having a substituent and an unsubstituted alkoxycarbonyloxy group. As the alkoxycarbonyloxy group, an alkoxycarbonyloxy group having 2 to 20 carbon atoms is preferable. Specific examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group and an isopropoxycarbonyloxy group.

  Examples of the aryloxycarbonyloxy group include an aryloxycarbonyloxy group having a substituent and an unsubstituted aryloxycarbonyloxy group. The aryloxycarbonyloxy group is preferably an aryloxycarbonyloxy group having 7 to 20 carbon atoms. Specific examples of the aryloxycarbonyloxy group include a phenoxycarbonyloxy group.

  The amino group includes an amino group substituted with an alkyl group, an aryl group, or a heterocyclic group, and the alkyl group, aryl group, and heterocyclic group may further have a substituent. The alkylamino group is preferably an alkylamino group having 1 to 20 carbon atoms. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the alkylamino group include a methylamino group and a diethylamino group. Examples of the arylamino group include an arylamino group having a substituent and an unsubstituted arylamino group. The arylamino group is preferably an arylamino group having 6 to 20 carbon atoms. Specific examples of the substituent include a halogen atom and an ionic hydrophilic group. Specific examples of the arylamino group include an anilino group and a 2-chlorophenylamino group. Examples of the heterocyclic amino group include a heterocyclic amino group having a substituent and an unsubstituted heterocyclic amino group. As the heterocyclic amino group, a heterocyclic amino group having 2 to 20 carbon atoms is preferable. Specific examples of the substituent include an alkyl group, a halogen atom, and an ionic hydrophilic group.

  Examples of the acylamino group include a substituted acylamino group and an unsubstituted acylamino group. The acylamino group is preferably an acylamino group having 2 to 20 carbon atoms. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the acylamino group include an acetylamino group, a propionylamino group, a benzoylamino group, an N-phenylacetylamino group, and a 3,5-disulfobenzoylamino group.

  Examples of the ureido group include a ureido group having a substituent and an unsubstituted ureido group. The ureido group is preferably a ureido group having 1 to 20 carbon atoms. Specific examples of the substituent include an alkyl group and an aryl group. Specific examples of the ureido group include a 3-methylureido group, a 3,3-dimethylureido group, and a 3-phenylureido group.

  Examples of the sulfamoylamino group include a sulfamoylamino group having a substituent and an unsubstituted sulfamoylamino group. Specific examples of the substituent include an alkyl group. Specific examples of the sulfamoylamino group include N, N-dipropylsulfamoylamino group.

  Examples of the alkoxycarbonylamino group include a substituted alkoxycarbonylamino group and an unsubstituted alkoxycarbonylamino group. As the alkoxycarbonylamino group, an alkoxycarbonylamino group having 2 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the alkoxycarbonylamino group include an ethoxycarbonylamino group.

  Examples of the aryloxycarbonylamino group include an aryloxycarbonylamino group having a substituent and an unsubstituted aryloxycarbonylamino group. The aryloxycarbonylamino group is preferably an aryloxycarbonylamino group having 7 to 20 carbon atoms. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the aryloxycarbonylamino group include a phenoxycarbonylamino group.

  Examples of the alkyl or arylsulfonylamino group include a substituted alkyl or arylsulfonylamino group and an unsubstituted alkyl or arylsulfonylamino group. As the sulfonylamino group, a sulfonylamino group having 1 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the sulfonylamino group include a methylsulfonylamino group, an N-phenyl-methylsulfonylamino group, a phenylsulfonylamino group, and a 3-carboxyphenylsulfonylamino group.

  Examples of the heterocyclic sulfonylamino group include a heterocyclic sulfonylamino group having a substituent and an unsubstituted heterocyclic sulfonylamino group. The heterocyclic sulfonylamino group is preferably a heterocyclic sulfonylamino group having 1 to 12 carbon atoms. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the heterocyclic sulfonylamino group include a 2-thiophenesulfonylamino group and a 3-pyridinesulfonylamino group.

  Examples of the alkyl or arylthio group include a substituted alkyl or arylthio group and an unsubstituted alkyl or arylthio group. As the alkyl or arylthio group, those having 1 to 20 carbon atoms are preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the alkyl or arylthio group include a methylthio group and a phenylthio group.

  Examples of the heterocyclic thio group include a heterocyclic thio group having a substituent and an unsubstituted heterocyclic thio group. As the heterocyclic thio group, those having 1 to 20 carbon atoms are preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the heterocyclic thio group include a 2-pyridylthio group.

  Examples of the alkyl or arylsulfonyl group include a substituted alkyl or arylsulfonyl group and an unsubstituted alkyl or arylsulfonyl group. Specific examples of the alkyl or arylsulfonyl group include a methylsulfonyl group and a phenylsulfonyl group.

  Examples of the heterocyclic sulfonyl group include a substituted heterocyclic sulfonyl group and an unsubstituted heterocyclic sulfonyl group. As the heterocyclic sulfonyl group, a heterocyclic sulfonyl group having 1 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the heterocyclic sulfonyl group include a 2-thiophenesulfonyl group and a 3-pyridinesulfonyl group.

  Examples of the alkyl or arylsulfinyl group include a substituted alkyl or arylsulfinyl group and an unsubstituted alkyl or arylsulfinyl group. Specific examples of the alkyl or arylsulfinyl group include a methylsulfinyl group and a phenylsulfinyl group.

  Examples of the heterocyclic sulfinyl group include a heterocyclic sulfinyl group having a substituent and an unsubstituted heterocyclic sulfinyl group. As the heterocyclic sulfinyl group, a heterocyclic sulfinyl group having 1 to 20 carbon atoms is preferable. Specific examples of the substituent include an ionic hydrophilic group. Specific examples of the heterocyclic sulfinyl group include a 4-pyridinesulfinyl group.

  Examples of the sulfamoyl group include a sulfamoyl group having a substituent and an unsubstituted sulfamoyl group. Specific examples of the substituent include an alkyl group. Specific examples of the sulfamoyl group include a dimethylsulfamoyl group and a di- (2-hydroxyethyl) sulfamoyl group.

  In general formula (I), each M is independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. Specific examples of the alkali metal include lithium, sodium, and potassium. Specific examples of the organic ammonium include acetamide, benzamide, methylamino, butylamino, diethylamino, phenylamino, and triethanolamino.

In the compound of the general formula (I) used in the present invention, A is an optionally substituted naphthyl group, and B is preferably a group represented by the above general formula (2). R ₃ in the general formula (2) is more preferably an aryl group or a pyridyl group. Specific examples of the aryl group or pyridyl group are as follows. Phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group and the like. Also, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 3,4-dimethylphenyl group, 2,6-dimethylphenyl group, 3,5-dimethylphenyl group, etc. . In addition, 2,4,6-trimethylphenyl group, 2,3,4-trimethylphenyl group, 2,3,5-trimethylphenyl group, 2,3,6-trimethylphenyl group and the like. Moreover, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group and the like. In addition, a 2-ethylphenyl group, a 3-ethylphenyl group, a 4-ethylphenyl group, and the like. Moreover, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 1-naphthyl group, 2-naphthyl group and the like. Among these, phenyl group, 3-methylphenyl group, 4-methylphenyl group, 2-chlorophenyl group, 3-chlorophenyl group, 2-pyridyl group, 4-pyridyl group, 1-naphthyl group, 2-naphthyl group, etc. Is preferred.

The compound of the general formula (I) preferably has a maximum absorption wavelength (λ _max ) of 590 nm or more and 620 nm or less of an absorption spectrum measured using water as a solvent.

  Preferable specific examples of the compound of the general formula (I) include the following exemplified compounds I-1 to I-12. The present invention is not limited to the following exemplified compounds as long as they are included in the structure of the general formula (I). In the present invention, among the following exemplified compounds, exemplified compounds I-3, I-5, I-6, I-8, I-9, I-10, I-11, and I-12 are used. It is more preferable to use Exemplified Compounds I-3, I-5, and I-10.

（一般式（II）中、Ｒ₁₀はそれぞれ独立に、水素原子、ヒドロキシル基、カルボキシル基、ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルキル基。ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルコキシル基、ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルキルアミノ基。カルボキシル−炭素数１乃至５のアルキルアミノ基、ビス−〔カルボキシ−炭素数１乃至５のアルキル〕アミノ基、ヒドロキシル基若しくは炭素数１乃至４のアルコキシ基によって置換されていてもよい炭素数１乃至４のアルカノイルアミノ基。カルボキシル基若しくはスルホン酸基若しくはアミノ基で置換されていてもよいフェニルアミノ基、スルホン酸基、ハロゲン原子、又はウレイド基である。［Ｃ］はカルボキシル基又はスルホン酸基を有する脂肪族アミン残基である。Ｍはそれぞれ独立に、水素原子、アルカリ金属、アンモニウム、又は有機アンモニウムである。） [Second coloring material: compound represented by formula (II)]
The ink of the present invention needs to contain a compound of the following general formula (II) as the second color material.

(In the general formula (II), each R ₁₀ independently represents 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 4. Alkylamino group, which is substituted by carboxyl-C1-C5 alkylamino group, bis- [carboxy-C1-C5 alkyl] amino group, hydroxyl group or C1-C4 alkoxy group Alkanoylamino group having 1 to 4 carbon atoms, carboxyl group or sulfonic acid group Or a phenylamino group optionally substituted with an amino group, a sulfonic acid group, a halogen atom, or a ureido 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.)

R ₁₀ in the general formula (II) is each 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 with an alkoxy group having 1 to 4 carbon atoms. 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxyl group having 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group or an alkoxy group which has 1 to 4 carbon atoms An alkylamino group. 1 to 5 carbon atoms optionally substituted by a carboxyl-alkyl group having 1 to 5 carbon atoms, a bis- [carboxy-alkyl having 1 to 5 carbon atoms] amino group, a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms 4 alkanoylamino groups. A phenylamino group, a sulfonic acid group, a halogen atom, or a ureido group which may be substituted with a carboxyl group, a sulfonic acid group, or an amino group.

  Specific examples of the alkyl group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms include the following groups. Methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, methoxyethyl, ethoxyethyl, n-propoxyethyl, isopropoxyethyl. Examples include n-butoxyethyl, sec-butoxyethyl, tert-butoxyethyl, and 2-hydroxyethyl.

  Specific examples of the alkoxy group having 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms include the following groups. Methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy, methoxyethoxy, ethoxyethoxy. Examples include n-propoxyethoxy, isopropoxyethoxy, n-butoxyethoxy, methoxypropoxy, ethoxypropoxy, n-propoxypropoxy, isopropoxybutoxy, n-propoxybutoxy, and 2-hydroxyethoxyethoxy.

  Specific examples of the alkylamino group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms include the following groups. Methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, N, N-dimethylamino, N, N-diethylamino, N, N-di (n-propyl) amino, N, N -Di (isopropyl) amino. Examples include hydroxyethylamino, 2-hydroxypropylamino, 3-hydroxypropylamino, bis (hydroxyethyl) amino, methoxyethylamino, ethoxyethylamino, bis (methoxyethyl) amino, bis (2-ethoxyethyl) amino and the like. .

  Specific examples of the carboxy-C 1-5 alkylamino group include carboxymethylamino, carboxyethylamino, carboxypropylamino, carboxy-n-butylamino, and carboxy-n-pentylamino.

  Specific examples of the bis- [carboxy-alkyl having 1 to 5 carbon atoms] amino group include bis- (carboxymethyl) amino group, bis- (carboxyethyl) amino group, and bis- (carboxypropyl) amino group. Etc.

  Specific examples of the alkanoylamino group having 1 to 4 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms include the following groups. Acetylamino, n-propionylamino, isopropionylamino, hydroxyacetylamino, 2-hydroxy-n-propionylamino, 3-hydroxy-n-propionylamino, 2-methoxy-n-propionylamino. Examples include 3-methoxy-n-propionylamino, 2-hydroxy-n-butyrylamino, 3-hydroxy-n-butyrylamino, 2-methoxy-n-butyrylamino, 3-methoxy-n-butyrylamino, and the like.

  Specific examples of the phenylamino group optionally substituted with a carboxyl group, a sulfonic acid group, or an amino group include the following groups. Examples include phenylamino, sulfophenylamino, carboxyphenylamino, biscarboxyphenylamino, aminophenylamino, diaminophenylamino, and diaminosulfophenylamino.

  Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. Among them, a chlorine atom or a bromine atom is preferable, and a chlorine atom is particularly preferable.

  Specific examples of the ureido group include 3-methylureido group, 3,3-dimethylureido group, and 3-phenylureido group.

  [C] in the general formula (II) is an aliphatic amine residue having a carboxyl group or a sulfonic acid group. As the aliphatic amine residue, an alkylamine residue having 1 to 5 mono-carbons or an alkylamine residue having 1 to 5 di-carbons having a carboxyl group or a sulfonic acid group is preferable. Specific examples of the aliphatic amine residue having a carboxyl group or a sulfonic acid group include the following. Amino-C1-C5 alkylsulfonic acid, diimino-C1-C5 alkylsulfonic acid, amino-C1-C5 alkyl carboxylic acid, diimino-C1-C5 alkyl carboxylic acid, etc. are mentioned. It is done. Among these, aliphatic carbon number is preferably 1 or 2. As the aliphatic amine residue having a carboxyl group or a sulfonic acid group, a sulfoethylamino group and a dicarboxymethylimino group are particularly preferable, and a sulfoethylamino group is more preferable.

  M in the general formula (II) is each independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. Specific examples of the alkali metal include lithium, sodium, and potassium. Examples of the organic ammonium include acetamide, benzamide, methylamino, butylamino, diethylamino, and phenylamino.

In the compound of the general formula (II) used in the present invention, R ₁₀ is preferably an alkyl group having 1 to 4 carbon atoms, and R ₁₀ is more preferably a methyl group. Incidentally, in the general formula (II), in the two benzene rings which R ₁₀ is substituted, it is preferred that R ₁₀ is substituted one for each benzene ring. In the four benzene rings substituted by the sulfonic acid group (—SO ₃ M), it is preferable that one sulfonic acid group is substituted for each benzene ring.

The compound of the general formula (II) preferably has a maximum absorption wavelength (λ _max ) of 400 nm or more and 440 nm or less of an absorption spectrum measured using water as a solvent.

  Preferable specific examples of the compound of the general formula (II) include the following exemplified compounds II-1 to II-12. Illustrative compounds II-1 to II-12 are compounds in which [C] in the following general formula (7) is an aliphatic amine residue shown in Table 1 below. The present invention is not limited to the following exemplified compounds as long as they are included in the structure of the general formula (II). In the present invention, it is particularly preferable to use the exemplified compounds II-1, II-5, and II-9 among the following exemplified compounds.

（一般式（７）中、Ｍはそれぞれ独立に、水素原子、アルカリ金属、アンモニウム、又は有機アンモニウムである。）

(In general formula (7), each M is independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium.)

（一般式（III）中、Ｄは、置換基を有するフェニル基である。該置換基は、カルボキシル基、スルホン酸基、塩素原子、シアノ基、ニトロ基、スルファモイル基、炭素数１乃至４のアルキル基。炭素数１乃至４のアルコキシ基（ヒドロキシル基、炭素数１乃至４のアルコキシ基、スルホン酸基、又はカルボキシル基で置換されていてもよい）。炭素数１乃至４のアルキルスルホニル基（ヒドロキシル基、スルホン酸基、又はカルボキシル基で置換されていてもよい）からなる群から選ばれる。Ｅ及びＦはそれぞれ独立に、置換基を有するパラフェニレン基である。該置換基は、カルボキシル基、スルホン酸基、炭素数１乃至４のアルキル基、炭素数１乃至４のアルコキシ基（ヒドロキシル基、炭素数１乃至４のアルコキシ基、スルホン酸基、又はカルボキシル基で置換されていてもよい）。炭素数１乃至４のアルキルスルホニル基（ヒドロキシル基、スルホン酸基、又はカルボキシル基で置換されていてもよい）からなる群から選ばれる。Ｒ₁₁は、カルボキシル基で置換されていてもよい炭素数１乃至４のアルキル基、スルホン酸基で置換されていてもよいフェニル基、又はカルボキシル基のいずれかである。Ｒ₁₂は、シアノ基、カルバモイル基、又はカルボキシル基のいずれかである。Ｒ₁₃及びＲ₁₄はそれぞれ独立に、水素原子、メチル基、塩素原子、又はスルホン酸基のいずれかである。） [Third coloring material: compound represented by general formula (III)]
The ink of the present invention needs to contain a compound of the following general formula (III) as the third color material.

(In the general formula (III), D is a phenyl group having a substituent. The substituent is a carboxyl group, a sulfonic acid group, a chlorine atom, a cyano group, a nitro group, a sulfamoyl group, or a group having 1 to 4 carbon atoms. 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), an alkylsulfonyl group having 1 to 4 carbon atoms ( E and F are each independently a paraphenylene group having a substituent, which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl 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, sulfonic acid group, May be substituted by carboxyl group). Alkylsulfonyl group (hydroxyl group of carbon number 1 to 4, .R ₁₁ selected from the group consisting of may also) be substituted with a sulfonic acid group, or a carboxyl group 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 or a carbamoyl group. Or R ₁₃ and R ₁₄ are each independently a hydrogen atom, a methyl group, a chlorine atom, or a sulfonic acid group.)

  D in the general formula (III) is a substituted phenyl group. Carboxyl group, sulfonic acid group, chlorine atom, cyano group, nitro group, sulfamoyl 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, sulfone) It may be substituted with an acid group or a carboxyl group). It has a substituent selected from the group consisting of 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).

  Specific examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

  Specific examples of the alkoxy group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group, an alkoxyl group having 1 to 4 carbon atoms, a sulfonic acid group, or a carboxyl group include the following groups. Methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy, methoxyethoxy, ethoxyethoxy, n-propoxyethoxy. Isopropoxyethoxy, n-butoxyethoxy, methoxypropoxy, ethoxypropoxy, n-propoxypropoxy, isopropoxybutoxy, n-propoxybutoxy, 2-hydroxyethoxyethoxy, carboxymethoxy. Examples include 2-carboxyethoxy, 3-carboxypropoxy, 3-sulfopropoxy, and 4-sulfobutoxy.

  Specific examples of the alkylsulfonyl group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group include the following groups. Methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, hydroxyethylsulfonyl, 2-hydroxypropylsulfonyl, 2-sulfoethylsulfonyl. Examples include 3-sulfopropylsulfonyl, 2-carboxyethylsulfonyl, and 3-carboxypropylsulfonyl.

  E and F in the general formula (III) are each independently a substituted paraphenylene group having a substituent. Examples of the substituent include a carboxyl group, a sulfonic acid group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms (a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, a sulfonic acid group, or a carboxyl group. May be substituted). It is selected from the group consisting of 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).

  Specific examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

  Specific examples of the alkoxy group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group, an alkoxyl group having 1 to 4 carbon atoms, a sulfonic acid group, or a carboxyl group include the following groups. . Methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy. Methoxyethoxy, ethoxyethoxy, n-propoxyethoxy, isopropoxyethoxy, n-butoxyethoxy, methoxypropoxy, ethoxypropoxy, n-propoxypropoxy, isopropoxybutoxy. Examples include n-propoxybutoxy, 2-hydroxyethoxyethoxy, carboxymethoxy, 2-carboxyethoxy, 3-carboxypropoxy, 3-sulfopropoxy, and 4-sulfobutoxy.

  Specific examples of the alkylsulfonyl group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group include the following groups. Methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, hydroxyethylsulfonyl. Examples include 2-hydroxypropylsulfonyl, 2-sulfoethylsulfonyl, 3-sulfopropylsulfonyl, 2-carboxyethylsulfonyl, and 3-carboxypropylsulfonyl.

R ₁₁ in the general formula (III) is 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.

  Specific examples of the alkyl group having 1 to 4 carbon atoms which may be substituted with a carboxyl group include the following groups. Examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, carboxymethyl, 2-carboxyethyl and the like.

  Specific examples of the phenyl group which may be substituted with a sulfonic acid group include phenyl, 3-sulfophenyl, 4-monosulfophenyl, 2,4-disulfophenyl, and 3,5-disulfophenyl. Can be mentioned.

R ₁₂ in the general formula (III) is a cyano group, a carbamoyl group, or a carboxyl group.
R ₁₃ and R ₁₄ in formula (III) are each independently a hydrogen atom, a methyl group, a chlorine atom, or a sulfonic acid group.

  In the compound of the general formula (III) used in the present invention, the substituent of D is preferably the following group. Specifically, a cyano group, a carboxyl group, a sulfonic acid group, a sulfamoyl group, a methylsulfonyl group, a 2-hydroxyethylsulfonyl group, a 3-sulfopropylsulfonyl group, and a nitro group. Examples include methyl group, methoxy group, ethyl group, ethoxy group, 2-hydroxyethoxy group, 2-sulfoethoxy group, 3-sulfopropoxy group, 4-sulfobutoxy group, carboxymethoxy group, and 2-carboxyethoxy group. . Among these, a cyano group, a carboxyl group, a sulfonic acid group, a sulfamoyl group, a methylsulfonyl group, a hydroxyethylsulfonyl group, a 3-sulfopropylsulfonyl group, or a nitro group is particularly preferable. In particular, a carboxyl group or a sulfonic acid group is more preferable.

  In the compound of the general formula (III) used in the present invention, the substituents which E and F (substituted paraphenylene group) have are preferably each independently the following groups. Specifically, carboxyl group, sulfonic acid group, methyl group, methoxy group, ethyl group, ethoxy group, 2-hydroxyethoxy group, 2-sulfoethoxy group. Examples include 3-sulfopropoxy group, 4-sulfobutoxy group, carboxymethoxy group, and 2-carboxyethoxy group. Among these, a sulfonic acid group, a methyl group, a methoxy group, a 2-hydroxyethoxy group, a 2-sulfoethoxy group, a 3-sulfopropoxy group, or a carboxymethoxy group is particularly preferable. Among these, a sulfonic acid group, a methyl group, a methoxy group, or a 3-sulfopropoxy group is more preferable. E and F each preferably independently have 1 to 3, more preferably 1 to 2 of these substituents.

（一般式（６）中、Ｒ₁₅は、スルホン酸基、又はスルホプロポキシ基であり、Ｒ₁₆は、水素原子、メチル基、エチル基、メトキシ基、又はエトキシ基である。） In the general formula (III) used in the present invention, E and F (substituted paraphenylene group) are preferably each independently a group represented by the following general formula (6).

(In the general formula (6), R ₁₅ is a sulfonic acid group or a sulfopropoxy group, and R ₁₆ is a hydrogen atom, a methyl group, an ethyl group, a methoxy group, or an ethoxy group.)

As a preferable combination of R ₁₅ and R ₁₆ in the general formula (6), when R ₁₅ is a sulfonic acid group and R ₁₆ is a hydrogen atom, or R ₁₅ is a 3-sulfopropoxy group and R ₁₆ is a methyl group. There are cases.

In the compound of the general formula (III) used in the present invention, R ₁₁ is preferably the following group. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a t-butyl group, a carboxymethyl group, a phenyl group, a 4-sulfophenyl group, and a carboxyl group. Among these, a methyl group, an n-propyl group, a carboxymethyl group, and a 4-sulfophenyl group are particularly preferable, and a methyl group and an n-propyl group are more preferable.

As a preferable combination of R ₁₁ and R ₁₂ in the compound of the general formula (III) used in the present invention, when R ₁₁ is a methyl group and R ₁₂ is a cyano group, or R ₁₁ is a methyl group and R ₁₂ is a carbamoyl group. Is the case.

R ₁₃ and R ₁₄ in the compound of the general formula (III) used in the present invention are each independently preferably a hydrogen atom, a methyl group, and a sulfonic acid group. As a preferable combination of R ₁₃ and R ₁₄ in the compound of the general formula (III), when R ₁₃ is a hydrogen atom and R ₁₄ is a sulfonic acid group, or R ₁₃ is a sulfonic acid group and R ₁₄ is a hydrogen atom. There are cases.

  When the compound represented by the general formula (III) is a salt, the cation forming the salt can be an inorganic or organic cation. When an inorganic or organic cation is represented by M, each M is independently a hydrogen atom, an alkali metal, ammonium, or organic ammonium. Specific examples of the alkali metal include lithium, sodium, and potassium. Examples of the organic ammonium include acetamide, benzamide, methylamino, butylamino, diethylamino, and phenylamino.

The compound of the general formula (III) preferably has a maximum absorption wavelength (λ _max ) of an absorption spectrum measured using water as a solvent of 540 nm or more and 570 nm or less.

  Preferred specific examples of the compound of the general formula (III) include the following exemplified compounds III-1 to III-20. The following exemplary compounds are described in the form of free acid. Of course, the present invention is not limited to the following exemplary compounds as long as they are included in the structure of the general formula (III) and the definition thereof. In the present invention, it is particularly preferable to use exemplified compounds III-6, III-13, III-15, and III-17 among the following exemplified compounds.

[Color material verification method]
To verify whether or not the color material used in the present invention is contained in the 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 of (1) (3) M / Z (posi), M / Z (negative) of mass spectrum for peak of (1)

The analysis conditions of high performance liquid chromatography are as follows. First, a liquid (ink) diluted about 1,000 times with pure water was prepared and used as a measurement sample. And the analysis by a high performance liquid chromatography was performed on the following conditions, and the retention time (retention time) of a peak and the maximum absorption wavelength of a peak were measured.
Column: SunFire C ₁₈ (Nippon Waters) 2.1 mm x 150 mm
-Column temperature: 40 ° C
・ Flow rate: 0.2 mL / min
PDA: 200 nm to 700 nm
-Mobile phase and gradient conditions: Table 2

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

  Under the method and conditions described above, as representative examples of the respective color materials, exemplary compound I-5 which is a specific example of the first color material, exemplary compound II-1 which is a specific example of the second color material, and Measurement was performed on Illustrative Compound III-17, which is a specific example of the third coloring material. As a result, the obtained retention time, maximum absorption wavelength, M / Z (posi), and M / Z (negative) values are shown in Table 3. When the unknown ink is measured under the same method and conditions as described above and corresponds to the values shown in Table 3, it can be determined that the compound contains a compound corresponding to the compound used in the present invention.

[Content of coloring material]
The content of the first color material (compound of general formula (I)), the content of the second color material (compound of general formula (II)), and the third color material (general formula (III) in the ink The content of the compound ()) is preferably set as described below from the viewpoint of color tone and light resistance.

  The content (% by mass) of the first color material in the ink is based on the total content (% by mass) of all the color materials in the ink, that is, [all the first color material / all the inks in the ink]. Colorant] × 100 is preferably 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 may not be obtained.

  The content (mass%) of the second color material in the ink is based on the sum (mass%) of the content of all the color materials in the ink, that is, [the second color material / all the ink in the ink]. Colorant] × 100 is preferably 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 particular, when the value of [second color material / all color materials in ink] × 100 is more than 12.0% and 25.0% or less, even in an image having gradation, Also in the image after the light resistance test, the color tone as black ink is more preferable.

  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.

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

  In the present invention, the total content (% by mass) of the first color material, the second color material, and the third color material in the ink is 0.1% by mass or more and 15% by mass based on the total mass of the ink. It is preferable that it is 0.0 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 color tone preferable as the black ink in the present invention, that is, the color tone that is neutral and gives a preferable image specifically means the following. For an image having gradation that is formed using black ink with a recording duty reduced from 100%, a ^* and b in an L ^* a ^* b ^* display system defined by the CIE (International Lighting Commission) Measure ^* . An ink having values of a ^* and b ^* 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 formed by reducing the recording duty, 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.

(Aqueous medium)
In the ink of the present invention, water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent can be used. 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 When the content of the water-soluble organic solvent is less than the above range, reliability such as ejection stability may not be obtained when the ink is used in an ink jet recording apparatus. Further, if the content of the water-soluble organic solvent is larger than the above range, the viscosity of the ink is increased and ink supply failure may occur.

  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. Lower 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. 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.

(Other additives)
In addition to the components described above, the ink of the present invention contains a water-soluble organic compound that is solid at room temperature, such as polyhydric alcohols such as trimethylolpropane and trimethylolethane, and urea derivatives such as ethyleneurea, as necessary. You may contain. Further, the ink of the present invention is optionally provided with a surfactant, a pH adjuster, a rust inhibitor, an antiseptic, an antifungal agent, an antioxidant, a reduction inhibitor, an evaporation accelerator, a chelating agent, and a water-soluble agent. You may contain various additives, such as a polymer.

(Other inks)
Further, in order to form a full-color image or the like, the ink of the present invention can be used in combination with an ink having a color tone different from that of the ink of the present invention. The ink of the present invention is preferably used together with at least one kind of ink selected from, for example, black ink, cyan ink, magenta ink, yellow ink, red ink, green ink and blue ink. Further, so-called light ink having substantially the same color tone as these inks can be used in combination. The color material of these inks or light inks may be a known dye or a newly synthesized color material.

<Recording medium>
As the recording medium used for forming an image using the ink of the present invention, any recording medium can be used as long as the recording medium is provided with 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.

  Specifically, the following fine particles can be used. Inorganic pigments such as aluminum oxide such as silica, clay, talc, calcium carbonate, kaolin, alumina or alumina hydrate, diatomaceous earth, titanium oxide, hydrotalcite, or zinc oxide. Organic pigments such as urea formalin resin, ethylene resin, styrene resin. These fine particles can be used alone or in combination of two or more as required.

  Examples of the binder include water-soluble polymers and latex. Specifically, the following can be used. Polyvinyl alcohol, starch, gelatin, or modified products thereof. Arabic gum. Cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, or hydroxyprooylmethylcellulose. Vinyl-based copolymer latex such as SBR latex, NBR latex, methyl methacrylate-butadiene copolymer latex, functional group-modified polymer latex, or ethylene vinyl acetate copolymer. Polyvinyl pyrrolidone. Maleic anhydride or a copolymer thereof, or an acrylate copolymer. These binders can use 1 type (s) or 2 or more types as needed.

  In addition, additives can be used as necessary. For example, dispersants, thickeners, pH adjusters, lubricants, fluidity modifiers, surfactants, antifoaming agents, mold release agents, optical brighteners, ultraviolet absorbers, antioxidants, dye fixing agents, etc. Can be used.

  In particular, when an image is formed using the ink of the present invention, it is preferable to use a recording medium in which an ink receiving layer is formed mainly of fine particles having an average particle diameter of 1 μm or less. Specific examples of the fine particles include silica fine particles and aluminum oxide fine particles. A preferable silica fine particle is a silica fine particle typified by colloidal silica. Although a colloidal silica can also use a commercial item, it is preferable to use especially the colloidal silica described in patent 2803134, 2881847, for example. Further, preferable examples of the aluminum oxide fine particles include alumina hydrate fine particles (alumina pigments).

Among the alumina pigments, an alumina hydrate such as pseudoboehmite represented by the following formula can be particularly preferable.
AlO _3-n (OH) _2n · mH ₂ O
(In the formula, n is an integer of 1 to 3, and m is 0 to 10, preferably 0 to 5. However, m and n are not 0 at the same time.)

mH ₂ O often also represents a detachable aqueous phase that is not involved in the formation of the mH ₂ O crystal lattice. For this reason, m can take an integer or a non-integer value. Also, when this type of alumina hydrate is heated, m can reach zero.

  Alumina hydrate can be produced by the following known methods. For example, it can be produced by hydrolysis of aluminum alkoxide or hydrolysis of sodium aluminate described in US Pat. No. 4,242,271 and US Pat. No. 4,202,870. Moreover, it can manufacture by the method of adding aqueous solution, such as sodium sulfate and aluminum chloride, to aqueous solution, such as sodium aluminate described in Japanese Patent Publication No.57-44605.

  The recording medium preferably has a support for supporting the ink receiving layer. The support is not particularly limited as long as the ink receiving layer can be formed of the above-described porous fine particles and gives rigidity that can be transported by a transport mechanism such as an ink jet recording apparatus. Can also be used. For example, a paper support composed of a pulp raw material mainly composed of natural cellulose fibers can be used. In addition, a plastic support made of a material such as polyester (for example, polyethylene terephthalate), cellulose triacetate, polycarbonate, polyvinyl chloride, polypropylene, or polyimide can be used. Furthermore, a resin-coated paper (eg, RC paper) having a polyolefin resin coating layer added with a white pigment or the like on at least one surface of the base paper can be used.

<Inkjet recording method>
The ink of the present invention is used in the ink jet recording method of the present invention in which recording is performed on a recording medium by ejecting the ink by an ink jet method. 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 the ink of the present invention, the ink cartridge of the present invention provided with an ink storage portion for storing such ink can be mentioned.

<Recording unit>
A recording unit suitable for performing recording using the ink of the present invention includes the recording unit of the present invention provided with an ink storage portion for storing such ink and a recording head for discharging the ink. 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 the present invention, it is particularly 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 composing the heat generating part wetted surface include, for example, metals such as Ta, Zr, Ti, Ni, and Al, or oxides of these metals. It is done.

<Inkjet recording apparatus>
An ink jet recording apparatus suitable for performing recording using the ink of the present invention includes the ink jet recording apparatus of the present invention provided with an ink storage portion for storing such ink and a recording head for discharging the ink. . In particular, 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 can be preferably used.

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

  The cleaning unit cleans the recording head H1001 before and after forming 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 configuration 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 forms an image with yellow, magenta, cyan, black, light magenta, light cyan, and green inks. Therefore, the ink cartridge H1900 is also prepared for seven colors independently. In the above, the ink 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 green ink nozzle row H2500, and a light magenta ink nozzle row H2600, are formed. ing.

Each nozzle row is composed of 768 nozzles arranged at an interval of 1200 dpi (dot / inch; reference value) in the recording medium conveyance direction (sub-scanning direction). Each nozzle ejects about 2 picoliters of ink. For this reason, the opening area in each discharge port is set to about 100 μm ² .

  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.

  The ink 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 and a comparative example, this invention is not limited at all by the following Example, unless the summary is exceeded. Unless otherwise specified, the ink components in Examples and Comparative Examples mean “parts by mass”.

<Preparation of coloring material>
Each exemplified compound was prepared according to the procedure shown below. In addition, about each obtained exemplary compound, water was made into the solvent, and the maximum absorption wavelength ((lambda) _max ) of the absorption spectrum was measured on condition of the following.
・ Spectrophotometer: Self-recording spectrophotometer (trade name: U-3300; manufactured by Hitachi, Ltd.)
・ Measurement cell: 1 cm quartz cell ・ Sampling interval: 0.1 nm
・ Scanning speed: 30nm / min

(Synthesis of Exemplified Compounds I-3 and I-5 and Measurement of Characteristic Values)
The exemplified compound I-3 (M: lithium) and the exemplified compound I-5 (M: lithium) were synthesized according to the method described in Patent Document 1. Exemplified compounds I-3 and I-5 correspond to those obtained by converting the b-6 and c-4 dyes described in Patent Document 1 into a lithium salt form, respectively. The maximum absorption wavelength (λ _max ) of the absorption spectrum measured using water as a solvent was 608 nm for Exemplified Compound I-3 and 604 nm for Exemplified Compound I-5.

(Synthesis of Exemplified Compounds II-1 and II-9 and Measurement of Characteristic Values)
Exemplified Compound II-1 (M: sodium) and Exemplified Compound II-9 (M: sodium) were respectively synthesized according to the methods described in Examples 1 and 2 of Patent Document 2. The maximum absorption wavelength (λ _max ) of the absorption spectrum measured using water as a solvent was 414 nm for Exemplified Compound II-1 and 436 nm for Exemplified Compound II-9.

(Synthesis of exemplary compound III-6 and measurement of characteristic values)
The exemplified compound III-6 (M: sodium) was synthesized according to the procedure shown below.
(1) Synthesis of Compound of Formula (9) In 100 parts of water, 21.7 parts of 5-sulfoanthranilic 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 (8) obtained by the method described in JP-A-2004-083492 was added to 240 parts of water, and the pH was 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 (9).

(2) Synthesis of compound of formula (10) 7.1 parts of the compound of formula (9) obtained above are 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 a solution obtained by dissolving 3.6 parts of the compound of the above formula (8) in 30 parts of water and adding sodium hydroxide to pH 4.5 to 5.5, and the temperature of the solution was changed to 15 to 25. 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 (10).

(3) Synthesis of Compound of Formula (12) 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 (11) 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 (12).

(4) Synthesis of Exemplary Compound III-6 The wet cake containing the disazo compound of the formula (10) obtained in (2) 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 (12) obtained in the above (3) in 50 parts of water to a pH of 8.0 to 9.0 by adding sodium hydroxide. The solution was added dropwise at a temperature of 20-30 ° 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 Exemplified Compound III-6 (sodium salt) having the following structure. With respect to the obtained Exemplified Compound III-6, the maximum absorption wavelength (λ _max ) of the absorption spectrum measured using water as a solvent was 553 nm.

(Synthesis of Exemplified Compound III-17 and Measurement of Characteristic Values)
Exemplified compound III-17 (M: sodium) was synthesized according to the procedure shown below.
(1) Synthesis of Compound of Formula (13) In the synthesis method (1) of Exemplified Compound III-6 described above, 2-aminobenzene-1,5-disulfonic acid 25 instead of 21.7 parts of 5-sulfoanthranilic acid .3 parts were used. Other than this, the compound of the following formula (13) was obtained in the same manner as in the synthesis method (1) of the exemplified compound III-6 described above.

(2) to (4) Synthesis of Exemplified Compound III-17 In the synthesis method (2) of Exemplified Compound III-6 described above, the compound of Formula (13) above instead of 7.1 parts of Compound of Formula (9) above 7.6 parts were used. Except this, Exemplified Compound III-17 (sodium salt) having the following structure was obtained in the same manner as in Synthesis Methods (2) to (4) of Exemplified Compound III-6 described above. With respect to the obtained Exemplified Compound III-17, the maximum absorption wavelength (λ _max ) of the absorption spectrum measured using water as a solvent was 557.5 nm.

<Preparation of ink>
Illustrative compounds I-3, I-5, II-1, II-9, III-6, III-17, and C.I. I. Using direct red 84 (sodium salt; comparative colorant), inks were prepared as follows. First, the components shown in Tables 4 to 7 below were mixed and sufficiently stirred. Then, pressure filtration was performed with a filter having a pore size of 0.2 μm to prepare black inks of Examples 1 to 17 and Comparative Examples 1 to 8. In the lower part of Tables 4 to 7, the total content of the color materials and the content of the color materials are values based on the total mass of the ink. The first to third color materials / all color materials × 100 [%] indicate the value of the ratio [%] of the content of each color material to the total content of the color materials. Further, the value of the second color material / the third color material [times] indicates the value of the mass ratio [times] of the content of the second color material to the content of the third color material.

<Evaluation>
(1) Color tone of initial image Each of the inks of Examples and Comparative Examples obtained above was mounted on an ink jet recording apparatus (trade name: PIXUS iP8600) using thermal energy. The recording conditions were a temperature of 23 ° C., a relative humidity of 55%, a recording density of 2,400 dpi × 1,200 dpi, and a discharge amount of 2.5 pL. Images with recording duty of 100%, 80%, 60%, 40%, 20%, and 10% were formed on recording medium PR-101 (manufactured by Canon). It was naturally dried at a humidity of 55% for 24 hours. For the image portion of each recorded matter obtained in this manner, the color tone of the initial image is measured by measuring a ^* and b ^* in the L ^* a ^* b ^* display system defined by the CIE (International Commission on Illumination). Was evaluated. In addition, a ^* and b ^* were measured using a spectrophotometer (Spectorolino; manufactured by Gretag Macbeth) under the conditions of light source: D50 and field of view: 2 °. The evaluation criteria for the color tone of the initial image are as follows. The evaluation results are shown in Table 8. In the present invention, when the following evaluation criteria are B or more, the color tone is neutral and the image is preferable.

AA: −5 ≦ a ^* ≦ 5 and −5 ≦ b ^* ≦ 5 are satisfied in images with a recording duty of 100%, 80%, 60%, 40%, 20%, and 10%.
A: In an image with a recording duty of 100%, −5 ≦ a ^* ≦ 5 and −5 ≦ b ^* ≦ 5 is satisfied, and in an image with a recording duty of 80%, 60%, 40%, 20%, and 10% — 10 ≦ a ^* ≦ 10 and −10 ≦ b ^* ≦ 10 are satisfied.
B: In an image with a recording duty of 100%, −5 ≦ a ^* ≦ 5 and −5 ≦ b ^* ≦ 5 is satisfied, but at least one of images with a recording duty of 80%, 60%, 40%, 20%, and 10% Therefore, −10 ≦ a ^* ≦ 10 and −10 ≦ b ^* ≦ 10 are not satisfied.
C: −5 ≦ a ^* ≦ 5 and −5 ≦ b ^* ≦ 5 are not satisfied in an image with a recording duty of 100%.

(2) Lightfastness The optical density of black (spectral sensitivity characteristics; using ISO Visual) was measured (“optical density before test”) for the portion of the recording duty 100% in the image of each recorded matter obtained above. To do). Furthermore, these recorded materials were exposed for 100 hours at an irradiation intensity of 100 kilolux, a bath temperature of 24 ° C., and a relative humidity of 60% using a super xenon tester (trade name: SX-75; manufactured by Suga Test Instruments). Thereafter, the black optical density (spectral sensitivity characteristics; using ISO Visual) was measured again for the portion of the recorded image with a recording duty of 100% (referred to as “optical density after test”). The optical density was measured using a spectrophotometer (Spectorolino; manufactured by Gretag Macbeth) under the conditions of light source: D50 and field of view: 2 °. From the obtained values of the optical density before the test and the optical density after the test, the residual ratio of the optical density was calculated based on the following formula, and the light resistance was evaluated. The criteria for light resistance are as follows. The evaluation results are shown in Table 8.

AA: The residual ratio of optical density is 95% or more.
A: The residual ratio of the optical density is 90% or more and less than 95%.
B: The residual ratio of the optical density is 85% or more and less than 90%.
C: The residual ratio of optical density is less than 85%.

(3) Color tone after light fastness test The color tone of each image after the light fastness test of (2) above was evaluated by measuring a ^* and b ^* under the same conditions as in (1) above. The evaluation criteria for the color tone after the light resistance test are the same as in (1) above. The evaluation results are shown in Table 8. In the present invention, when the above evaluation criterion is B or more, the color tone is neutral and the image is preferable.

(4) Optical density residual ratio in each wavelength region Using the inks of Examples 3 and 12 and Comparative Example 7, the recording duty is set to 100% (ink applied to the recording medium: 11 g / m ² ). Each of the obtained images was formed (the image before the light resistance test). About each obtained image, the light resistance test which exposes for 100 hours on the conditions of xenon irradiation intensity | strength 100 kilolux, the temperature in a tank 24 degreeC, and 60% of relative humidity was performed, and each image after a test was obtained (after light resistance test) Image). Spectral sensitivity characteristics in each wavelength region of yellow, magenta, and cyan in each image before the light resistance test and each image after the light resistance test obtained in this way; yellow, magenta, defined by ISO status A, And the optical density of each component of cyan was measured. The optical density was measured using a spectrophotometer (Spectorolino; manufactured by Gretag Macbeth) using a spectral sensitivity characteristic; ISO status A under conditions of a light source: D50 and a visual field: 2 °. Then, based on the optical density of each component measured above, the residual ratio of the optical density of the yellow component, magenta component, and cyan component (the calculation method of the residual ratio of each component is the same as the residual ratio of the optical density). Was calculated. Further, the difference between the maximum value and the minimum value of the residual ratio of the optical density among the residual ratios of the optical density in the obtained color components was obtained. Table 9 shows the obtained evaluation results.

  As is apparent from Table 9, the difference between the maximum value and the minimum value of the residual ratio of the optical density in each wavelength region of yellow, magenta, and cyan in Example 3 is 1%. In contrast, in Example 12, the difference between the maximum value and the minimum value of the residual ratio of optical density is 4%, and in Comparative Example 7, the difference between the maximum value and the minimum value of the residual ratio of optical density is 7%. It became bigger. If the difference between the maximum value and the minimum value of the residual ratio of the optical density in each wavelength region of yellow, magenta, and cyan is small as in Example 3, that is, if the difference in the degree of decrease in optical density is small, the image is Changes in color tone after fading due to exposure to light are reduced. As a result, even after the light resistance test, an excellent image with a color tone close to neutral can be obtained.

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. FIG. 6 is a chromaticity diagram on an a ^* b ^* plane in an image formed using black ink at a recording duty of 100%, 80%, 60%, 40%, 20%, and 10%. It is a schematic diagram showing the distribution position of each color material in the recording medium when ink containing each color material is applied to the recording medium.

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 M5010: Cap M7030: Access cover E0002: LF motor E0014: 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 board H1301: External signal input terminal H1400: Second plate H1500: Tank holder (cartridge Ruda)
H1501: Ink flow path H1600: Flow path forming member H1700: Filter H1800: Seal rubber H1900: Ink cartridge H2000: Yellow nozzle array H2100: Magenta nozzle array H2200: Cyan nozzle array H2300: Light cyan nozzle array H2400: Black nozzle array H2500: Green Nozzle row H2600: Light magenta nozzle row

Claims (9)

An ink containing at least a first color material, a second color material, and a third color material,
The first colorant is a compound represented by the following general formula (I):
The second colorant is a compound represented by the following general formula (II):
The ink, wherein the third color material is a compound represented by the following general formula (III).

(In the general formula (I), A is an optionally substituted naphthyl group, B is is Ru group represented by the following general formula (2), M is each independently a hydrogen atom, an alkali metal, ammonium Or organic ammonium.)

(In general formula ( 2 ), R ₃ represents a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a heterocyclic group, a carboxyl group, a carbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, or a heterocyclic oxycarbonyl group. Amino including acyl group, hydroxyl group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, anilino group and heterocyclic amino group Group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, cyano group, nitro group, alkyl or arylthio group, compound And a cyclic thio 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 may be further substituted.

(In the general formula (II), each R ₁₀ independently represents 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 group Or a phenylamino group optionally substituted with an amino group, a sulfonic acid group, a halogen atom, or a ureido 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 the general formula (III), D is a phenyl group having a substituent, and the substituent is a carboxyl group, a sulfonic acid group, a chlorine atom, a cyano group, a nitro group, a sulfamoyl group, or a group having 1 to 4 carbon atoms. 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, sulfonic acid , Or carboxyl which may be substituted with a group), and an alkylsulfonyl group (hydroxyl group of 1 to 4 carbon atoms, selected from the group consisting of a sulfonic acid group, or may be substituted by carboxyl group) .R ₁₁ is any 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, It is either 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.) Substituents D in the compound represented by the general formula (III) is a sulfonic acid group or carboxyl group, E and F is, according to claim 1 is a group represented by the following general formula (6) Ink.

(In the general formula (6), R ₁₅ is a sulfonic acid group or a sulfopropoxy group, and R ₁₆ is any one of a hydrogen atom, a methyl group, an ethyl group, a methoxy group, or an ethoxy group.) The content (% by mass) of the first color material in the 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 ink. The ink according to claim 1 or 2 . The content (mass%) of the second color material in the 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 ink. The ink according to any one of claims 1 to 3 . The content (mass%) of the first color material in the ink is 50.0% or more with respect to the total content (mass%) of all the color materials in the ink,
In addition, the content (mass%) of the second color material in the ink is 0.60 times or more and 1 in mass ratio with respect to the content (mass%) of the third color material in the ink. The ink according to any one of claims 1 to 4 , which is less than 0.000 times. 6. An ink jet recording method for performing recording on a recording medium by ejecting ink by an ink jet method, wherein the ink is the ink according to any one of claims 1 to 5 . An ink cartridge comprising an ink container for containing ink, wherein the ink is the ink according to any one of claims 1 to 5 . An ink storage portion for storing ink, a recording unit and a recording head for ejecting the ink, the ink, wherein the ink is an ink according to any one of claims 1 to 5 Recording unit. An ink jet recording apparatus comprising an ink containing portion for containing ink and a recording head for ejecting ink, wherein the ink is the ink according to any one of claims 1 to 5. Inkjet recording apparatus.

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