JP5434561B2 - Ink set, ink cartridge, ink jet recording method and recorded matter - Google Patents

Description

  The present invention relates to an ink set, particularly an ink set capable of forming an image excellent in ozone resistance, light resistance and moisture resistance, and an ink cartridge, an ink jet recording method and a recorded matter using the ink set.

  In recent years, ink jet recording methods have attracted attention. The ink jet recording method is a printing method in which printing is performed by causing an ink composition to fly as small droplets and attaching the droplets to a recording medium (media) such as paper. This method has a feature that a high-resolution and high-quality image can be printed at a high speed by a relatively inexpensive apparatus. Ink jet recording apparatuses using this method are widely accepted in the market due to excellent print quality, low cost, relatively quiet operation, and excellent graphic forming ability. Among them, thermal (Bubble Jet®) and piezoelectric drop-on-demand printers have been particularly successful commercially and have been widely used as printers for personal computers in offices and homes.

  In recent years, it has been practiced to form a color image by an ink jet recording method using a plurality of color ink compositions to obtain a recorded matter. In general, a color image is formed by three colors, ie, a yellow ink composition, a magenta ink composition, and a cyan ink composition, and further, if desired, four colors including a black ink composition. There are also cases where color images are formed by six colors obtained by adding a light cyan ink composition and a light magenta ink composition to these four colors, or seven colors obtained by further adding a dark yellow ink composition to them. A combination of two or more ink compositions is an ink set.

  In the ink composition used for forming the color image described above, the ink composition for each color itself has a good color developability, and a good intermediate color when a plurality of color ink compositions are combined. And the like, and the recorded material obtained should not discolor during storage.

  More recently, in “photo quality” printing by color inkjet printers, the head, ink composition, recording method, and media have been continuously improved, and the resulting image quality is comparable to “silver salt photography”. , "Like photo". On the other hand, improvement in the ink composition and the media has improved the storability of the image of the recorded matter obtained using the color ink jet printer, and in particular, the light resistance of the image is a level at which there is no practical problem. (See, for example, Patent Documents 1 and 2). However, image degradation is caused not only by the action of light but also by oxidation with an oxidizing gas present in the environment, such as ozone, or moisture (humidity) in the environment, and the fading or discoloration of the image proceeds. . Therefore, in order to further improve the storability of the image of the recorded matter, it is desired to improve the light resistance of the image formed by the ink composition as well as to improve the ozone resistance and the moisture resistance. . For this reason, various studies have been made to improve the light resistance, ozone resistance and moisture resistance of ink-jet recordings. Until now, the ozone resistance performance of colorants (coloring materials) used in ink compositions has been improved. Has been attempted (see, for example, Patent Documents 3 and 4).

  In addition, in an ink set, when the light resistance, ozone resistance, and moisture resistance of a specific ink composition are significantly lower than the light resistance, ozone resistance, and humidity resistance of other ink compositions, the specific ink composition The color formed by the color fading and discoloration occurs earlier than other colors, and the balance of the color tone of the entire image is worsened. However, the observer may fade the image formed by the single ink composition. The image quality deterioration of the image can be recognized within a shorter time than when the image can be recognized. Therefore, in the ink set, the light resistance, ozone resistance and moisture resistance level of each ink composition are improved in addition to improving the light resistance, ozone resistance and moisture resistance of each ink composition constituting the ink set. That is, it is preferable that the deterioration rate of the image formed by each ink composition by light, ozone and water, for example, the fading rate is as much as possible. In other words, each ink composition constituting the ink set is excellent in light resistance, ozone resistance and moisture resistance, and the difference in light resistance, ozone resistance and moisture resistance between the ink compositions is small. preferable.

  In addition, by configuring an ink set including two types of light and dark ink compositions having different color densities for similar colors, it is possible to form images with various color densities and obtain images without graininess. It was. Such an ink set containing two kinds of ink compositions having different color densities is mainly used for printing a photographic image. In the formation of a photographic image, in order to reduce or eliminate the graininess of the image, generally, the color density is used. Are often used. Also in the light resistance, ozone resistance, and moisture resistance evaluations described above, a pattern having an optical density of about 1.0 as an evaluation sample is formed by an ink composition having a low color density. Therefore, in order to improve the light resistance, ozone resistance and moisture resistance of the photographic image of the recorded matter, and the light resistance, ozone resistance and humidity resistance of the ink set as a whole, the light resistance of the ink composition having a low color density. It is important to improve ozone resistance and moisture resistance. On the other hand, since ink compositions having a high color density are used for printing of images with rich colors and graphic artistic patterns, it is also necessary to improve the light resistance, ozone resistance and moisture resistance of these ink compositions.

  Further, since the black ink composition plays an important role from the viewpoint of obtaining image contrast in an image, the black ink composition is often included in the ink set. Therefore, when the black ink composition is included in the ink set, the black ink composition has excellent light resistance, ozone resistance and moisture resistance, and the deterioration rate of the black ink composition due to light, ozone and water is It is necessary not to be extremely different from the deterioration rate of other ink compositions constituting the ink.

  As described above, in the ink set, each ink composition constituting the ink set itself has good light resistance, ozone resistance and moisture resistance, and light resistance, ozone resistance and moisture resistance between the ink compositions are good. There is a good balance and it is necessary to prevent certain colors from fading and / or discoloring faster when exposed to light, ozone and water than other colors. Furthermore, when it is attempted to improve light resistance, ozone resistance and moisture resistance in each ink composition constituting the ink set, a bronzing phenomenon may occur, and it is necessary to reduce the bronzing phenomenon. The bronze phenomenon is a red floating phenomenon observed in a printed portion when printing is performed at a high duty. In particular, the bronze phenomenon is solid using an ink composition using a metal phthalocyanine dye as a coloring material (coloring agent). There is a tendency to occur easily when printing (100% duty printing). The bronze phenomenon may cause the color balance of the entire image to be lost and the image quality to deteriorate.

In addition, an ink set that can improve image quality deterioration and record an image with good ozone resistance on a recording medium, an ink cartridge containing the ink set, and the ink set have been used so far. The recording method and the recorded matter recorded by the ink set have been proposed (see, for example, Patent Document 5).
Although such ink sets have practicality for consumer use with respect to light resistance and ozone resistance, further light resistance and ozone resistance are required for diversification of applications and diversion of inkjet technology to various fields. Improvement is awaited. Furthermore, ensuring moisture resistance is a necessary characteristic in order to cope with diversification of usage applications.

JP 2000-290559 A JP 2001-288392 A International Publication WO02 / 060994 JP 2002-371214 A JP-A-2005-105135

  The present invention has been completed to solve the above-described problems, and an ink set capable of recording an image having good ozone resistance, light resistance, and moisture resistance on a recording medium, and the ink set accommodated therein The present invention relates to an ink cartridge, a recording method using the ink set, and a recorded matter recorded by the ink set.

The ink set of the present invention is an ink set comprising at least a yellow ink composition, two types of magenta ink compositions having different color densities, and a cyan ink composition,
The magenta ink composition contains, as a colorant, at least one compound represented by the following formula (M-1) and at least one compound represented by the following formula (M-2),

（前記式（Ｍ-１）中、Ａは、５員複素環ジアゾ成分Ａ−ＮＨ₂の残基を表す。Ｂ¹およびＢ²は、各々−ＣＲ¹＝、-ＣＲ²＝を表すか、あるいはいずれか一方が窒素原子，他方が−ＣＲ¹＝または−ＣＲ²＝を表す。Ｒ⁵，Ｒ⁶は、各々独立に、水素原子、脂肪族基、芳香族基、複素環基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、アルキルスルホニル基、アリールスルホニル基、またはスルファモイル基を表わす。各基は更に置換基を有していてもよい。Ｇ、Ｒ¹、Ｒ²は、各々独立して、水素原子、ハロゲン原子、脂肪族基、芳香族基、複素環基、シアノ基、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、アシル基、ヒドロキシ基、アルコキシ基、アリールオキシ基、シリルオキシ基、アシルオキシ基、カルバモイルオキシ基、ヘテロ環オキシ基、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、アルキル基またはアリール基または複素環基で置換されたアミノ基、アシルアミノ基、ウレイド基、スルフアモイルアミノ基、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、アルキルおよびアリールスルホニルアミノ基、アリールオキシカルボニルアミノ基、ニトロ基、アルキルおよびアリールチオ基、アルキルおよびアリールスルホニル基、アルキルおよびアリールスルフィニル基、スルファモイル基、スルホ基、またはヘテロ環チオ基を表す。各基は更に置換されていてもよい。また、Ｒ¹とＲ⁵、あるいはＲ¹とＲ⁵が結合して５〜６員環を形成してもよい。）

(Wherein (M-1), A is .B ¹ and B ² represents a 5-membered heterocyclic diazo component A-NH ₂ residues, each -CR ¹ =, - or represents a CR ² =, Alternatively, either one represents a nitrogen atom and the other represents —CR ¹ ═ or —CR ² ═ R ⁵ and R ⁶ each independently represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, or an acyl group. Represents an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or a sulfamoyl group, wherein each group may further have a substituent, and G, R ¹ , and R ² are Each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carboxyl group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group, hydroxy group, alkoxy group, Lyloxy group, silyloxy group, acyloxy group, carbamoyloxy group, heterocyclic oxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group substituted with alkyl group, aryl group or heterocyclic group, acylamino group, ureido Group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl and arylsulfonylamino group, aryloxycarbonylamino group, nitro group, alkyl and arylthio group, alkyl and arylsulfonyl group, alkyl and arylsulfinyl Represents a group, a sulfamoyl group, a sulfo group, or a heterocyclic thio group, each group may be further substituted, and R ¹ and R ⁵ , or R ¹ and R ⁵ are bonded to form a 5- to 6-membered ring. The It may form.)

（前記式（Ｍ-２）中、Ｍは水素原子、アンモニウム基、又はアルカリ金属原子、Ｘはジアミノアルキレン基を表し、ｎは１又は２である。）
さらに前記イエローインク組成物が着色剤として、下記式（Ｙ-１）で表される化合物の少なくとも１種を含有し、

(In the formula (M-2), M represents a hydrogen atom, an ammonium group, or an alkali metal atom, X represents a diaminoalkylene group, and n is 1 or 2.)
Furthermore, the yellow ink composition contains at least one compound represented by the following formula (Y-1) as a colorant,

（上記式中、Ｘ₁、Ｘ₂、Ｙ₁、及びＹ₂は水素原子、又はシアノ基を表し、Ｚ₁及びＺ₂は芳香環を有する置換基を表し、Ｒ₁及びＲ₂はアルキル基を表し、Ｍは金属原子を表す。）
さらに前記シアンインク組成物がシアン染料として下記の式（Ｃ-１）：

(In the above formula, X ₁ , X ₂ , Y ₁ , and Y ₂ represent a hydrogen atom or a cyano group, Z ₁ and Z ₂ represent a substituent having an aromatic ring, and R ₁ and R ₂ represent an alkyl group. And M represents a metal atom.)
Further, the cyan ink composition as a cyan dye has the following formula (C-1):

（前記式（Ｃ-１）中、Ｘ₁、Ｘ₂、Ｘ₃及びＸ₄は、それぞれ独立に、−ＳＯ−Ｚ及び−ＳＯ₂−Ｚのいずれかを表す。ここで、Ｚは、それぞれ独立に、置換若しくは無置換のアルキル基、置換若しくは無置換のシクロアルキル基、置換若しくは無置換のアルケニル基、置換若しくは無置換のアラルキル基、置換若しくは無置換のアリール基、又は置換若しくは無置換のヘテロ環基を表す。
Ｙ₁、Ｙ₂、Ｙ₃及びＹ₄は、それぞれ独立に、水素原子、ハロゲン原子、アルキル基、シクロアルキル基、アルケニル基、アラルキル基、アリール基、ヘテロ環基、シアノ基、ヒドロキシ基、ニトロ基、アミノ基、アルキルアミノ基、アルコキシ基、アリールオキシ基、アミド基、アリールアミノ基、ウレイド基、スルファモイルアミノ基、アルキルチオ基、アリールチオ基、アルコキシカルボニルアミノ基、スルホンアミド基、カルバモイル基、アルコキシカルボニル基、ヘテロ環オキシ基、アゾ基、アシルオキシ基、カルバモイルオキシ基、シリルオキシ基、アリールオキシカルボニル基、アリールオキシカルボニルアミノ基、イミド基、ヘテロ環チオ基、ホスホリル基、アシル基、又はイオン性親水性基を表し、各々の基はさらに置換基を有していてもよい。
ａ₁〜a₄及びｂ₁〜ｂ₄は、それぞれＸ₁〜Ｘ₄及びＹ₁〜Ｙ₄の置換基数を表す。そして、ａ₁〜ａ₄は、それぞれ独立に、０〜４の整数であり、すべてが同時に０になることはない。ｂ₁〜ｂ₄は、それぞれ独立に、０〜４の整数を表す。
Ｍは、水素原子、金属原子又はその酸化物、水酸化物若しくはハロゲン化物である。
ただし、Ｘ₁、Ｘ₂、Ｘ₃、Ｘ₄、Ｙ₁、Ｙ₂、Ｙ₃及びＹ₄の内の少なくとも１つは
、イオン性親水性基であるか又はイオン性親水性基を置換基として有する基である。）
で表される化合物及びその塩からなる群から選ばれる少なくとも一種を含有することを特徴とするものである。

(In the formula (C-1), X ₁ , X ₂ , X ₃ and X ₄ each independently represent either —SO—Z or —SO ₂ —Z, where Z is each Independently, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted group Represents a heterocyclic group.
Y ₁ , Y ₂ , Y ₃ and Y ₄ are each independently a hydrogen atom, halogen atom, alkyl group, cycloalkyl group, alkenyl group, aralkyl group, aryl group, heterocyclic group, cyano group, hydroxy group, nitro Group, amino group, alkylamino group, alkoxy group, aryloxy group, amide group, arylamino group, ureido group, sulfamoylamino group, alkylthio group, arylthio group, alkoxycarbonylamino group, sulfonamido group, carbamoyl group, Alkoxycarbonyl group, heterocyclic oxy group, azo group, acyloxy group, carbamoyloxy group, silyloxy group, aryloxycarbonyl group, aryloxycarbonylamino group, imide group, heterocyclic thio group, phosphoryl group, acyl group, or ionic Represents a hydrophilic group, each group is further substituted It may have a group.
a ₁ ~a ₄ and b ₁ ~b ₄ each represent the number of substituents of X ₁ to X ₄ and Y ₁ to Y _4. A _{1 to} a ₄ are each independently an integer of 0 to 4, and all of them are not 0 at the same time. b ₁ ~b ₄ each independently represents an integer of 0-4.
M is a hydrogen atom, a metal atom or an oxide, hydroxide or halide thereof.
Provided that at least one of X ₁ , X ₂ , X ₃ , X ₄ , Y ₁ , Y ₂ , Y _3, and Y ₄ is an ionic hydrophilic group or a substituent on the ionic hydrophilic group. As a group possessed as )
It contains at least 1 type chosen from the group which consists of the compound represented by these, and its salt.

  Furthermore, in the ink set of the present invention, the compound represented by the formula (M-1) among the colorants contained in the magenta ink composition is a compound represented by the following formula (M-3). It is preferable.

（前記式（Ｍ-３）中、Ｒ₁〜Ｒ₅は水素原子、アルキル基、スルホ基又はその塩を表し、Ｒ₁、及びＲ₅はそれぞれ独立に、共にアルキル基のときはそのアルキル基を構成する炭素数の合計が３以上であってそれらに置換基を有していてもよい。Ｘは水素原子、脂肪族基、芳香族基、または複素環基を表し、Ｙ及びＺは各々独立に、水素原子、脂肪族基、芳香族基、複素環基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、アルキルスルホニル基、アリールスルホニル基、またはスルファモイル基を表す。各基は更に置換基を有していてもよい。）

(In the formula (M-3), R _{1 to} R ₅ represent a hydrogen atom, an alkyl group, a sulfo group or a salt thereof, and R ₁ and R ₅ are each independently an alkyl group when both are an alkyl group. The total number of carbon atoms constituting the carbon atom may be 3 or more and may have a substituent, X represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and Y and Z are each Independently, it represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or a sulfamoyl group. Furthermore, you may have a substituent.)

  Furthermore, in the ink set of the present invention, the compound represented by the formula (M-3) is preferably a compound represented by the following formula (M-4).

（前記式（Ｍ-４）中、Ｒ₁〜Ｒ₁₀は水素原子、アルキル基、スルホ基又はその塩を表し、（Ｒ₁，Ｒ₅）及び（Ｒ₆，Ｒ₁₀）は、それぞれ独立に、共にアルキル基を構成する炭素数の合計が３以上であってそれらに置換基を有していてもよい。また、Ｍは水素原子又はアルカリ金属原子を表す。）

(In the formula (M-4), R _{1 to} R ₁₀ represent a hydrogen atom, an alkyl group, a sulfo group or a salt thereof, and (R ₁ , R ₅ ) and (R ₆ , R ₁₀ ) are each independently And the total number of carbon atoms constituting the alkyl group is 3 or more and may have a substituent, and M represents a hydrogen atom or an alkali metal atom.)

  Furthermore, in the ink set of the present invention, it is preferable that n in the compound represented by the formula (M-2) among the colorants contained in the magenta ink composition is 2.

  Furthermore, in the ink set of the present invention, of the two types of magenta ink compositions having different color densities, the magenta ink composition having a low color density is at least one of the compounds represented by the formula (M-1). 1 type and at least one compound represented by the formula (M-2) as a colorant, and the total of the colorants is based on the total weight of the magenta ink composition having the low color density 0.2-1.0 wt% of at least one compound represented by formula (M-1) is contained, and at least one compound represented by formula (M-2) is 0.3- It is preferable to contain 1.5 wt%.

  Furthermore, in the ink set of the present invention, of the two types of magenta ink compositions having different color densities, the magenta ink composition having a high color density is at least a compound represented by the formula (M-1). 1 type and at least one compound represented by the formula (M-2) as a colorant, and the total of the colorants is based on the total weight of the magenta ink composition having the high color density 0.6-2.5 wt% of at least one compound represented by the formula (M-1) is contained, and at least one compound represented by the formula (M-2) is 1.5- It is preferable to contain 7.0 wt%.

  Furthermore, in the ink set of the present invention, in the magenta ink composition having a low color density among the two types of magenta ink compositions having different color densities, the compound represented by the formula (M-1); The content ratio with the compound represented by the formula (M-2) is preferably in the range of 2: 1 to 1: 2 by weight ratio.

  Furthermore, in the ink set of the present invention, in the magenta ink composition having a high color density among the two types of magenta ink compositions having different color densities, the compound represented by the formula (M-1); The content ratio with the compound represented by the formula (M-2) is preferably in the range of 1: 1 to 1: 8 by weight.

  Furthermore, in the ink set of the present invention, in the magenta ink composition, the content ratio of the compound represented by the formula (M-1) and the compound represented by the formula (M-2) is a weight ratio. In the range of 2: 1 to 1: 8.

  Furthermore, in the ink set of the present invention, it is preferable that the magenta ink composition contains a betaine surfactant represented by the following formula (b-1).

（前記式（ｂ-１）中、Ｒは、水素原子、アルキル基、アリール基、又は複素環基を表す。Ｌは２価以上の連結基を表す。Ｍは水素原子、アルカリ金属原子、アンモニウム基、プロトン化された有機アミンもしくは含窒素複素環基、４級アンモニウムイオン基を表し、式（ｂ-１）中のＮ原子からなるアンモニウムイオンの対イオンとなる場合は、カチオンとして存在しない基を表す。ｑは１以上の整数を表し、ｒは１以上４以下の整数を表す。ｐは０以上４以下の整数を表し、ｐ＋ｒは３もしくは４である。ｐ＋ｒが４である場合はＮは４級アミンを構成する窒素原子となる。ｐが２以上の時はＲは同じでも異なっていてもよい。ｑが２以上の時はＣＯＯＭは同じでも異なっていてもよい。ｒが２以上の時はＬ−（ＣＯＯＭ）_qは同じでも異なっていてもよい。）

(In the formula (b-1), R represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. L represents a divalent or higher linking group. M represents a hydrogen atom, an alkali metal atom, or ammonium. Group, a protonated organic amine or a nitrogen-containing heterocyclic group, a quaternary ammonium ion group, a group that does not exist as a cation when it is a counter ion of an ammonium ion consisting of an N atom in formula (b-1) Q represents an integer of 1 or more, r represents an integer of 1 to 4, p represents an integer of 0 to 4, and p + r is 3 or 4. When p + r is 4, N Is a nitrogen atom constituting a quaternary amine, R may be the same or different when p is 2 or more, COOM may be the same or different when q is 2 or more, r is 2 or more In the case of L- (COOM) _q is the same but different May be.)

  Furthermore, in the ink set of the present invention, the betaine surfactant represented by the formula (b-1) is preferably a compound represented by the following formula (b-2).

（式（ｂ-２）中、Ｒ１〜Ｒ３は、炭素数が１〜２０のアルキル基を表し、Ｘは、２価の連結基を表す。）

(In formula (b-2), R1 to R3 represent an alkyl group having 1 to 20 carbon atoms, and X represents a divalent linking group.)

  Furthermore, in the ink set of the present invention, it is preferable that the compound represented by the formula (b-2) is a compound represented by the following formula (b-3).

  Furthermore, in the ink set of the present invention, the content ratio of the compound represented by the formula (M-1) and the betaine surfactant represented by the formula (b-1) in the magenta ink composition. Is preferably in the range of 1: 3 to 3: 1 by weight.

  Furthermore, in the ink set of the present invention, the compound represented by the formula (Y-1) as a colorant contained in the yellow ink composition is a compound represented by the following formula (Y-2). It is preferable.

（上記式中、Ｘ₁、Ｘ₂、Ｙ₁、及びＹ₂は水素原子、又はシアノ基を表し、Ｗ₁〜Ｗ₅及びＷ₁₁〜Ｗ₁₅は、それぞれ水素原子、カルボキシル基又はその塩を表し、Ｍは金属原子を表し、ｔ−Ｂｕはターシャリーブチル基を表す。）

(In the above formula, X ₁ , X ₂ , Y ₁ , and Y ₂ represent a hydrogen atom or a cyano group, and W _{1 to} W ₅ and W _{11 to} W ₁₅ represent a hydrogen atom, a carboxyl group, or a salt thereof, respectively. M represents a metal atom, and t-Bu represents a tertiary butyl group.)

  Furthermore, in the ink set of the present invention, it is preferable that the yellow ink composition further contains at least one compound represented by the following formula (Y-3) as a colorant.

（上記式中、Ｒはメトキシ基又はメチル基を表し、Ａは１，５−ジスルフォナフト−３−イル又は１，５，７−トリスルフォナフト−２−イルを表す。）

(In the above formula, R represents a methoxy group or a methyl group, and A represents 1,5-disulfonaft-3-yl or 1,5,7-trisulfonaft-2-yl.)

  Furthermore, in the ink set of the present invention, it is preferable that the total amount of the colorant in the yellow ink composition is 1 to 7% by weight based on the total weight of the yellow ink composition.

Furthermore, in the ink set of the present invention, in the compound represented by the formula (C-1) as the cyan dye in the cyan ink composition, M is a copper atom, and X ₁ , X ₂ , X ₃ and X ₄ are —SO ₂ Z, and Z is R ⁵ (wherein R ⁵ represents — (CH ₂ ) ₃ SO ₃ M ² , where M ² represents an alkali metal atom) and / Or R ⁶ (wherein R ⁶ represents — (CH ₂ ) ₃ SO ₂ NHCH ₂ CH (OH) CH ₃ ), and Y ₁ , Y ₂ , Y ₃ and Y ₄ are hydrogen atoms. A ₁ , a ₂ , a ₃ and a ₄ are 0 or 1, and two or more of a ₁ , a ₂ , a ₃ and a ₄ are 1, and b ₁ , b ₂ , b ₃ and b ₄ are each preferably an integer such that the sum of a ₁ , a ₂ , a ₃ and a ₄ is 4.

Furthermore, in the ink set of the present invention, it is preferable that the M ² is Li.

Furthermore, in the ink set of the present invention, the cyan dye may be a tetrasulfonic acid compound selected from the group consisting of the R ^{5 and the} R ^{6 in the} compound represented by the formula (C-1). It is a mixture comprising a sulfonic acid form and a disulfonic acid form, and the molar ratio of R ⁵ and R ⁶ contained in the whole cyan dye is R ⁵ / R ⁶ = 2/2 to 4/0. preferable.

  Furthermore, in the ink set of the present invention, the cyan ink composition contains at least one selected from the group consisting of the compound represented by the formula (C-1) and a salt thereof as a colorant, and the coloring The total amount of the agent is preferably 1.0 to 10% by weight based on the total weight of the cyan ink composition.

  Furthermore, in the ink set of the present invention, the cyan ink composition includes two cyan ink compositions having different color densities, and the cyan ink composition is represented by the formula (C-1). It is preferable to contain at least one selected from the group consisting of a compound and a salt thereof.

  Furthermore, in the ink set of the present invention, of the two types of cyan ink compositions having different color densities, the cyan ink composition having a low color density is a compound represented by the formula (C-1) and a compound thereof. At least one selected from the group consisting of salts is included as a colorant, and the total amount of the colorant is 0.4 to 3.0% by weight based on the total weight of the cyan ink having the low color density. It is preferable.

  Furthermore, in the ink set of the present invention, of the two types of cyan ink compositions having different color densities, a cyan ink composition having a high color density is represented by the formula (C-1) as a colorant. 2.0 to 10.0% by weight based on the total weight of the cyan ink composition containing at least one selected from the group consisting of a compound and a salt thereof as a colorant, and the total amount of the colorant having the high color density % Content is preferable.

  Further, in the ink set of the present invention, in the two types of cyan ink compositions having different color densities, the colorant concentration (wt%) contained in the cyan ink composition having a low color density and a high color density are obtained. The ratio with the concentration (% by weight) of the colorant contained in the cyan ink composition is preferably in the range of 1: 2 to 1: 8 by weight.

Furthermore, in the ink set of the present invention, both of the two cyan ink compositions having different color densities are at least one selected from the group consisting of the compound represented by the formula (C-1) and a salt thereof. Tetrasulfone wherein Z is independently selected from R ⁵ or R ^{6 in the} compound represented by the formula (C-1) contained in a cyan ink composition which is contained as a colorant and has a low color density. It is a mixture comprising an acid body, a trisulfonic acid body, and a disulfonic acid body, and the molar ratio of R ⁵ and R ⁶ contained in the whole cyan dye is R ⁵ / R ⁶ = 1/3 to 3/1. On the other hand, in the compound represented by the formula (C-1) contained in the cyan ink composition having a high color density, Z is a tetrasulfonic acid compound independently selected from R ⁵ or R ⁶ , Trisle Phosphate body, and a mixture consisting of disulfonic acid product, and that the molar ratio of the R ⁵ and the R ⁶ contained in the entire cyan dye is ^{R 5 / R 6 = 2 /} 2~4 / 0 preferable.

  Furthermore, in the ink set of the present invention, among the two types of cyan ink compositions having different color densities, a cyan ink composition having a low color density is further represented by the following general formulas (a) and / or (b): It is preferable that the aromatic compound which has a sulfo group represented by this, and / or its salt are included.

（式中、Ｍ¹は水素原子又は塩を構成する対イオンを示し、Ｘは１以上の整数を示し、Ｒ¹及びＲ²はそれぞれ水素原子、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を示し、Ｒ¹及びＲ²は同一でも異なっていても良い。）

(In the formula, M ¹ represents a hydrogen atom or a counter ion constituting a salt, X represents an integer of 1 or more, R ¹ and R ² represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 carbon atom, respectively. ˜6 alkoxy groups, R ¹ and R ² may be the same or different.)

（式中、Ｍ²は水素原子又は塩を構成する対イオンを示し、Ｙは１以上の整数を示し、Ｒ³及びＲ⁴はそれぞれ水素原子、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を示し、Ｒ³及びＲ⁴は同一でも異なっていても良い。）

(In the formula, M ² represents a hydrogen atom or a counter ion constituting a salt, Y represents an integer of 1 or more, R ³ and R ⁴ represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 carbon atom, respectively. ˜6 alkoxy groups, R ³ and R ⁴ may be the same or different.)

  Furthermore, in the ink set of the present invention, the salt of the aromatic compound having a sulfo group represented by the general formula (a) and / or (b) is preferably a lithium salt.

  Further, in the ink set of the present invention, in the cyan ink composition having the low color density, the content ratio of the cyan dye and the aromatic compound having a sulfo group and / or a salt thereof is expressed by weight ratio. It is preferable that it exists in the range of 1: 1 to 1: 5.

  Furthermore, in the ink set of the present invention, among the two cyan ink compositions having different color densities, the cyan ink composition having a high color density is a naphthalene-based aromatic compound having a carboxyl group at the 2-position and It is preferable to contain at least one selected from the group consisting of salts.

  Furthermore, in the ink set of the present invention, it is preferable that the salt of the naphthalene aromatic compound having a carboxyl group at the 2-position is a lithium salt.

  Furthermore, the ink set of the present invention preferably further includes a black ink composition in the ink set.

  Furthermore, in the ink set of the present invention, it is preferable that the black ink composition contains a colorant represented by the following formula (Bk-1).

（式（Bｋ-１）中、Ａ₁は下記式（Bｋ-２）又は（Bｋ-３）で表される置換基であり、Ａ₂は下記式（Bｋ-４）又は（Bｋ-５）で表される置換基であり、Ａ₃は下記式（Bｋ-６）で表される置換基である。）

(In the formula (Bk-1), A ₁ is a substituent represented by the following formula (Bk-2) or (Bk-3), and A ₂ is the following formula (Bk-4) or (Bk-5). And A ₃ is a substituent represented by the following formula (Bk-6).)

（式（Bｋ-２）中、ＭはＬｉ又はＮａを表す。）

(In the formula (Bk-2), M represents Li or Na.)

（式（Bｋ-３）中、ＭはＬｉ又はＮａを表す。）

(In the formula (Bk-3), M represents Li or Na.)

（式（Bｋ-６）中、ＭはＬｉ又はＮａを表す。）

(In the formula (Bk-6), M represents Li or Na.)

  Furthermore, in the ink set of the present invention, it is preferable that the black ink composition further contains a colorant represented by the following formula (Bk-7).

（式（Bｋ-７）中、Ｒ₁は、ハロゲン原子、Ｈ、ＳＯ₃Ｍ、ＣＯＯＭのいずれかを示し、Ｒ₂及びＲ₃はそれぞれ独立に、Ｈ、ＳＯ₃Ｍ、ＣＯＯＭのいずれかを示し、Ｍは、Ｌｉ又はＮａを示す。ただし、Ｒ₂及びＲ₃がいずれもＨである場合はない。）

(In the formula (Bk-7), R ₁ represents a halogen atom, H, SO ₃ M, or COOM, and R ₂ and R ₃ independently represent any of H, SO ₃ M, or COOM. M represents Li or Na, provided that R ₂ and R ₃ are not H.)

  Furthermore, in the ink set of the present invention, the sum of the content of the colorant represented by the formula (Bk-1) and the content of the colorant represented by the formula (Bk-7) is the black color. The content is preferably 5 to 8% by weight in the ink composition.

  Furthermore, in the ink set of the present invention, the mixing ratio of the colorant represented by the formula (Bk-1) and the colorant represented by the formula (Bk-7) in the black ink composition is a weight. The ratio is preferably 2: 1 to 1: 2.

  Furthermore, in the ink set of the present invention, it is preferable that the black ink composition further contains a colorant represented by the following formula (Adj-1).

（式中、ＭはＬｉ又はＮａを表す。）

(In the formula, M represents Li or Na.)

  Furthermore, in the ink set of the present invention, it is preferable that the colorant represented by the formula (Adj-1) is a colorant represented by the following formula (Adj-1-1).

  Furthermore, in the ink set of the present invention, the black ink composition further contains C.I. I. It is preferable to contain Direct Yellow 86.

  Furthermore, in the ink set of the present invention, it is preferable that the ink composition contains a nonionic surfactant.

  Further, in the ink set of the present invention, it is preferable that the nonionic surfactant is an acetylene glycol surfactant.

  Furthermore, in the ink set of the present invention, the ink composition preferably contains 0.1 to 5% by weight of the nonionic surfactant.

  Furthermore, in the ink set of the present invention, it is preferable that the ink composition contains a penetration accelerator.

  Furthermore, in the ink set of the present invention, the penetration accelerator is preferably a glycol ether.

  The ink cartridge of the present invention is characterized in that the ink set is accommodated integrally or independently.

  The inkjet recording method of the present invention is characterized by recording using the ink set or the ink cartridge.

  The recorded matter of the present invention is recorded using the ink set or the ink cartridge.

  The ink set of the present invention uses a compound represented by the above formula (C-1) and a salt thereof (hereinafter also referred to as a dye of the formula (C-1)) as a colorant for the cyan ink composition. A compound represented by the formula (M-1) and a compound represented by the formula (M-2) are used as colorants of two types of magenta ink compositions having different color densities, and the yellow ink composition By using the compound represented by the formula (Y-1) as a colorant, it is possible to improve the ozone resistance, light resistance and moisture resistance of an image of a recorded matter printed using this ink set.

  The inventors of the present invention configured an ink set by combining various ink compositions of a plurality of colors, and conducted studies for improving ozone resistance, light resistance, and moisture resistance of an image formed using the ink set. As a result, when an image was recorded using a cyan ink composition using a dye having the specific structure, two magenta ink compositions having different color densities, and an ink set containing a yellow ink composition, The recorded image is excellent in ozone resistance, light resistance and moisture resistance, and the deterioration of cyan, magenta and yellow (and each color formed by ink in the ink set such as black if necessary) image by ozone and light. It has been found that since the difference in speed is small, an observer can obtain an ink set in which the observer hardly perceives the deterioration of the entire image even if the deterioration of the image by ozone and light progresses to some extent. Hereinafter, for two types of magenta ink compositions having different color densities in the ink set of the present invention, magenta having a high color density is referred to as a “dark magenta ink composition”, and a magenta ink composition having a low color density is referred to as “light”. It is referred to as “magenta ink composition”.

  Further, the present inventors have referred to two types of cyan ink compositions having different color densities (hereinafter, a cyan ink composition having a high color density is referred to as a “dark cyan ink composition”), In an ink set including a cyan ink composition having a density is referred to as a “light cyan ink composition”), a dye having the above-described specific structure as a colorant for both the dark cyan ink composition and the light cyan ink composition It has been found that an ink set having particularly preferable ozone resistance, light resistance and moisture resistance can be obtained.

Furthermore, the present inventors have found that the ink set of the present invention is preferable as an ink set used in an ink jet recording method.
The present invention has been completed based on these findings.

  The ink set according to the first aspect of the present invention includes a yellow ink composition, two types of magenta ink compositions having different color densities, and a cyan ink composition. The cyan ink composition and the yellow ink composition in the first aspect of the present invention each include at least one compound having the specific structure as a colorant, and two types of magenta ink compositions having different color densities, Each of them contains at least one compound having two specific structures.

The ink set according to the second aspect of the present invention is the ink set according to the first aspect, wherein at least two cyan ink compositions having different color densities as the cyan ink composition as desired, that is, at least a dark cyan ink composition. And a light cyan ink composition, and both the dark cyan ink composition and the light cyan ink composition preferably contain at least one of the dyes having the specific structure as a colorant. .
Furthermore, since a dark cyan ink composition containing a dye having a specific structure may cause a bronzing phenomenon in a printed image, in order to suppress this, the group consisting of an aromatic compound having a specific structure having a carboxyl group and a salt thereof It is preferable to use at least one selected from On the other hand, the light cyan ink composition containing the dye having the specific structure is preferable because it can improve ozone resistance by containing at least one selected from the group consisting of an aromatic compound having a sulfone group and a salt thereof. .

  The ink set according to the third embodiment of the present invention is the ink set according to the first or second aspect, further having a black ink composition. The black dye used in the black ink composition is preferably at least one selected from the group consisting of dyes having the specific structure.

  Any of the ink sets of the present invention is used in a recording method using an ink composition. Examples of a recording method using an ink composition include an ink jet recording method, a recording method using a writing instrument such as a pen, various other types of printing, and the like. A printing method is mentioned. The ink set of the present invention is particularly preferable as an ink set used in an ink jet recording method.

  Each ink composition contained in the ink set of the present invention will be described. First, the colorant contained in each ink composition will be described below for each color ink composition. In the ink set of the present invention, in each color ink composition, by using a dye having a specific chemical structure as a colorant, the ink set as a whole has excellent ozone resistance, light resistance and moisture resistance. Can do.

  The colorant used in the cyan ink composition constituting the ink set of the present invention will be described. In the present invention, the cyan dye used as a colorant in the cyan ink composition is represented by the following formula (C-1):

で表されるフタロシアニン化合物及びその塩からなる群から選ばれる化合物である。

It is a compound chosen from the group which consists of phthalocyanine compound represented by these, and its salt.

Here, in formula _{(C-1), X 1} , X 2, X 3 and X ₄ independently represents any of -SO-Z and -SO ₂ -Z. Here, each Z is independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group. Or a substituted or unsubstituted heterocyclic group.
Y ₁ , Y ₂ , Y ₃ and Y ₄ are each independently a hydrogen atom, halogen atom, alkyl group, cycloalkyl group, alkenyl group, aralkyl group, aryl group, heterocyclic group, cyano group, hydroxy group, nitro Group, amino group, alkylamino group, alkoxy group, aryloxy group, amide group, arylamino group, ureido group, sulfamoylamino group, alkylthio group, arylthio group, alkoxycarbonylamino group, sulfonamido group, carbamoyl group, Alkoxycarbonyl group, heterocyclic oxy group, azo group, acyloxy group, carbamoyloxy group, silyloxy group, aryloxycarbonyl group, aryloxycarbonylamino group, imide group, heterocyclic thio group, phosphoryl group, acyl group, or ionic Represents a hydrophilic group, each group is further substituted It may have a group.
a ₁ ~a ₄ and b ₁ ~b ₄ each represent the number of substituents of X ₁ to X ₄ and Y ₁ to Y _4. A _{1 to} a ₄ are each independently an integer of 0 to 4, and all of them are not 0 at the same time. b ₁ ~b ₄ each independently represents an integer of 0-4.
M is a hydrogen atom, a metal atom or an oxide, hydroxide or halide thereof.
Provided that at least one of X ₁ , X ₂ , X ₃ , X ₄ , Y ₁ , Y ₂ , Y _3, and Y ₄ is an ionic hydrophilic group or a substituent on the ionic hydrophilic group. As a group possessed as

In the present invention, in the formula (C-1), a ₁ , a ₂ , a ₃ and a ₄ are 0 or 1, and two or more of a ₁ , a ₂ , a ₃ and a ₄ are It is preferable that b ₁ , b ₂ , b ₃ and b ₄ are integers with the sum of a ₁ , a ₂ , a ₃ and a ₄ being 4, respectively.

As described above, in the formula (C-1), X ₁ , X ₂ , X ₃ and X ₄ each independently represent either —SO—Z or —SO ₂ —Z, and Z is further substituted. The substituent which Z can have is a halogen atom (for example, a chlorine atom or a bromine atom); a linear or branched alkyl group having 1 to 12 carbon atoms, carbon 7 to 18 aralkyl groups, 2 to 12 alkenyl groups, 2 to 12 linear or branched alkynyl groups, and 3 to 12 carbon cycloalkyls optionally having side chains A C3-C12 cycloalkenyl group optionally having a side chain (for example, methyl, ethyl, propyl, isopropyl, t-butyl, 2-methanesulfonylethyl, 3-phenoxypropyl) , Trifluoromethyl, An aryl group (eg, phenyl, 4-t-butylphenyl, 2,4-di-t-amylphenyl); a heterocyclic group (eg, imidazolyl, pyrazolyl, triazolyl, 2-furyl, 2-thienyl, 2 -Pyrimidinyl, 2-benzothiazolyl); alkyloxy group (for example, methoxy, ethoxy, 2-methoxyethoxy, 2-methanesulfonylethoxy); aryloxy group (for example, phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 3-t-butyloxycarbamoylphenoxy, 3-methoxycarbamoyl); acylamino group (eg, acetamide, benzamide, 4- (3-t-butyl-4-hydroxyphenoxy) butanamide); alkylamino group ( For example, methylamino Anilino group (eg, phenylamino, 2-chloroanilino; ureido group (eg, phenylureido, methylureido, N, N-dibutylureido)); sulfamoylamino group (eg, butylamino, diethylamino, methylbutylamino); N, N-dipropylsulfamoylamino); alkylthio group (for example, methylthio, octylthio, 2-phenoxyethylthio); arylthio group (for example, phenylthio, 2-butoxy-5-t-octylphenylthio, 2-carboxyphenyl) Thio); alkyloxycarbonylamino group (for example, methoxycarbonylamino); sulfonamide group (for example, methanesulfonamide, benzenesulfonamide, p-toluenesulfonamide, octadecane); carbamoyl group (for example, -Ethylcarbamoyl, N, N-dibutylcarbamoyl); sulfamoyl group (eg, N-ethylsulfamoyl, N, N-dipropylsulfamoyl, N, N-diethylsulfamoyl); sulfonyl group (eg, methanesulfonyl) , Octanesulfonyl, benzenesulfonyl, toluenesulfonyl); alkyloxycarbonyl group (for example, methoxycarbonyl, butyloxycarbonyl); heterocyclic oxy group (for example, 1-phenyltetrazol-5-oxy, 2-tetrahydropyranyloxy); An azo group (eg, phenylazo, 4-methoxyphenylazo, 4-pivaloylaminophenylazo, 2-hydroxy-4-propanoylphenylazo); an acyloxy group (eg, acetoxy); a carbamoyloxy group (eg, N Methylcarbamoyloxy, N-phenylcarbamoyloxy); silyloxy groups (eg trimethylsilyloxy, dibutylmethylsilyloxy); aryloxycarbonylamino groups (eg phenoxycarbonylamino); imide groups (eg N-succinimide, N-phthalimid) A heterocyclic thio group (for example, 2-benzothiazolylthio, 2,4-di-phenoxy-1,3,5-triazole-6-thio, 2-pyridylthio); a sulfinyl group (for example, 3-phenoxypropyl) A phosphonyl group (eg, phenoxyphosphonyl, octyloxyphosphonyl, phenylphosphonyl); an aryloxycarbonyl group (eg, phenoxycarbonyl); an acyl group (eg, acetyl, 3-phenylpropanoyl, An ionic hydrophilic group (for example, carboxyl group, sulfo group, and quaternary ammonium group); cyano group; hydroxy group; nitro group; amino group and the like.

  In addition, the ionic hydrophilic group in the formula (C-1) includes a sulfo group, a carboxyl group, a quaternary ammonium group, and the like. As the ionic hydrophilic group, a carboxyl group and a sulfo group are preferable, and a sulfo group is particularly preferable. The carboxyl group and the sulfo group may be in a salt state, and specific examples of the counter ion forming the salt include an alkali metal ion (eg, sodium ion, potassium ion, lithium ion) and an organic cation (eg, tetra Methyl guanidinium ion).

Of the compounds represented by the formula (C-1), M in the formula (C-1) is a copper atom, X _{1 to} X ₄ are represented by —SO ₂ Z, and the Z is R ⁵ ( R ⁵ is, - (CH ₂₎ represents a ₃ SO ₃ M ^2, wherein M ² represents an alkali metal atom) and / or R ⁶ (R ⁶ _{is, - (CH 2). 3} SO 2 NHCH 2 CH (OH) represents CH _3. ), And a compound in which M ² is Li is more preferable. In particular, the compound represented by the formula (C-1) is preferably a mixture of a tetrasulfonic acid body, a trisulfonic acid body, and a disulfonic acid body in which R ⁵ / R ⁶ (molar ratio) = 3/1. The tetra sulfonic acid derivative, trisulphonic acid derivative, and disulfonic acid derivative, when all four of a ₁ ~a ₄ is 1 in each of the formulas (C-1), three of a ₁ ~a ₄ This corresponds to the case where 1 is 1 and 0, and 2 out of a _{1 to} a ₄ are 1 and 2 are 0.

In particular, in the compound represented by the formula (C-1) as the cyan dye, M is a copper atom, X ₁ , X ₂ , X ₃ and X ₄ are —SO ₂ Z, and Z represents R ⁵ (wherein R ⁵ represents — (CH ₂ ) ₃ SO ₃ M ² , where M ² represents an alkali metal atom) and / or R ⁶ (wherein R ⁶ represents — (CH _{2 3} SO ₂ NHCH ₂ CH (OH) CH ₃ ), Y ₁ , Y ₂ , Y ₃ and Y ₄ are hydrogen atoms, and a ₁ , a ₂ , a ₃ and a ₄ are 0 or 1 and two or more of a ₁ , a ₂ , a ₃ and a ₄ are 1, and b ₁ , b ₂ , b ₃ and b ₄ are a ₁ , a ₂ , a ₃ , respectively. and if the sum of the a ₄ is an integer which is a 4, it is possible to ensure the color material of good hue (including saturation), particularly preferable because it can ensure water-soluble.
In this case, it is even more preferable that M ² is Li, since the water-solubility of the coloring material can be secured and bronze can be avoided.

In this case, Z is a mixture of a tetrasulfonic acid body, a trisulfonic acid body, and a disulfonic acid body independently selected from R ⁵ or R ⁶ , and is included in the cyan dye as a whole. The molar ratio of R ⁵ and R ⁶ is preferably R ⁵ / R ⁶ = 1/3 to 4/0, because both ozone resistance and bronze suppression are achieved at a high level.

  A method for synthesizing the compound represented by the formula (C-1) is shown below.

In the above reaction formula, the phthalocyanine compound represented by the general formula II is an embodiment of the compound represented by the formula (C-1) and is a compound that can be used in the present invention. The phthalocyanine compound represented by the general formula II is represented by, for example, a phthalonitrile compound represented by the general formula III and / or a diiminoisoindoline derivative represented by the general formula IV and M- (Y) d. It can be synthesized by reacting a metal derivative. In General Formula II, General Formula III, and General Formula IV, Z and Z _{1 to} Z ₄ have the same meaning as Z in Formula (C-1), and M is M in Formula (C-1). It is synonymous with. Here, Y represents a monovalent or divalent ligand such as a halogen atom, acetate anion, acetylacetonate, or oxygen, and d is an integer of 1 to 4. Examples of the metal derivative represented by M- (Y) d include Al, Si, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Ge, Ru, Rh, Pd, In, Sn, Pt, and Pb. And halides, carboxylic acid derivatives, sulfates, nitrates, carbonyl compounds, oxides, and complexes. Specific examples of this metal derivative include copper chloride, copper bromide, copper iodide, nickel chloride, nickel bromide, nickel acetate, cobalt chloride, cobalt bromide, cobalt acetate, iron chloride, zinc chloride, zinc bromide, iodine. Zinc chloride, zinc acetate, vanadium chloride, vanadium oxytrichloride, palladium chloride, palladium acetate, aluminum chloride, manganese chloride, manganese acetate, acetylacetone manganese, manganese chloride, lead chloride, lead acetate, indium chloride, titanium chloride, and tin chloride Etc.

The compound represented by the general formula II thus obtained is usually (SO ₂ -Z ₁ ), (SO ₂ -Z ₂ ), (SO ₂ -Z ₃ ) in the general formula II, and (SO ₂ —Z ₄ ) (these groups also correspond to R ₁ , R ₂ , R ₃ , and R ₄ in the formula (1)), which is an isomer of the following general formula (a) It is a mixture of the compounds represented by -1 to (a) -4.

In the present invention, the content of the cyan-based dye contained in the cyan ink composition is the type of X ₁ to X ₄ and Y ₁ to Y ₄ in formula (C-1), and to produce the ink composition In the present invention, the total amount of the cyan dye represented by the formula (C-1) (the dye of the formula (C-1)) is included in the cyan ink composition. The cyan ink composition preferably contains 1 to 10% by weight, more preferably 2 to 6% by weight. When the total amount of the dye of the formula (C-1) contained in the cyan ink composition is 1% by weight or more, the color developability of the ink on the recording medium when printed can be improved and is required. Image density can be secured. Further, by making the total amount of the dye of the formula (C-1) contained in the cyan ink composition 10% by weight or less, the discharge property of the cyan ink composition can be improved when used in the ink jet recording method. In addition, it is possible to obtain an effect such that the inkjet nozzle is not easily clogged.

  In the ink set of the present invention, as a cyan ink composition, a cyan ink composition having a high color density (hereinafter also referred to as a dark cyan ink composition) and a cyan ink composition having a low color density (hereinafter also referred to as a light cyan ink composition). Can be included in the ink set. When the dark cyan ink composition and the light cyan ink composition are included in the ink set of the present invention, both the dark cyan ink composition and the light cyan ink composition are at least one dye of the formula (C-1) as a colorant. It is preferable to include as.

  As described above, when a dark cyan ink composition and a light cyan ink composition are included in the ink set, the concentration of the colorant in the light cyan ink composition depends on the type of dye used as the colorant. When the composition is combined with the dark cyan ink composition, it can be appropriately determined so as to have a preferable color balance.

In general, the light cyan ink composition preferably contains 0.4 to 3.0% by weight of the total amount of the dye of the formula (C-1) with respect to the total weight of the light cyan ink composition. By making the concentration of the colorant in the light cyan ink composition 0.4% by weight or more, the color developability can be made excellent, and the concentration of the colorant is made 3.0% by weight or less. Therefore, it is possible to reduce the graininess of an image recorded using the light cyan ink composition.
On the other hand, the dark cyan ink composition contains 2.0 to 10.0% by weight of the total amount of the dye of formula (C-1) with respect to the total weight of the dark cyan ink composition. This is preferable from the viewpoint of securing the discharge reliability such as clogging and clogging.

  Further, the ratio between the concentration (% by weight) of the colorant contained in the light cyan ink composition and the concentration (% by weight) of the colorant contained in the dark cyan ink composition is 1: 2 to 1: 8. Preferably there is. By satisfying such conditions, a good color balance is realized between the light cyan ink composition and the dark cyan ink composition, and the ink jet nozzle can be prevented from being clogged.

In the present invention, in particular, both the dark and light cyan ink compositions contain at least one selected from the group consisting of the compound represented by the formula (C-1) and a salt thereof as a colorant, and among them, the light cyan ink composition formula (C-1) Z is independently in the compound represented by the by the R ⁵ or the tetrasulfonic acid derivative selected from R ⁶ contained in the object, consisting trisulphonic acid derivative, and disulfonic acid product The molar ratio of R ⁵ and R ⁶ contained in the whole cyan dye is R ⁵ / R ⁶ = 1/3 to 3/1, while the above-mentioned contained in the dark cyan ink composition. In the compound represented by the formula (C-1), Z is a mixture composed of a tetrasulfonic acid body, a trisulfonic acid body, and a disulfonic acid body independently selected from R ⁵ or R ⁶ , and All cyan dyes It is preferred that the molar ratio of the R ⁵ and the R ⁶ is ^{R 5 / R 6 = 3 /} 1~4 / 0 contained in. In this case, in particular, it is possible to maintain the bronze resistance in a well-balanced manner while ensuring the ozone resistance of the light cyan ink composition.

  Of the light and light cyan ink compositions, the light cyan ink composition further contains an aromatic compound having a sulfo group represented by the following general formula (a) and / or (b) and / or a salt thereof. It is preferable in terms of further improving the ozone resistance of the recorded image.

（式中、Ｍ¹は水素原子又は塩を構成する対イオンを示し、Ｘは１以上の整数を示し、Ｒ¹及びＲ²はそれぞれ水素原子、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を示し、Ｒ¹及びＲ²は同一でも異なっていても良い。）

(In the formula, M ¹ represents a hydrogen atom or a counter ion constituting a salt, X represents an integer of 1 or more, R ¹ and R ² represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 carbon atom, respectively. ˜6 alkoxy groups, R ¹ and R ² may be the same or different.)

（式中、Ｍ²は水素原子又は塩を構成する対イオンを示し、Ｙは１以上の整数を示し、Ｒ³及びＲ⁴はそれぞれ水素原子、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を示し、Ｒ³及びＲ⁴は同一でも異なっていても良い。）

(In the formula, M ² represents a hydrogen atom or a counter ion constituting a salt, Y represents an integer of 1 or more, R ³ and R ⁴ represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 carbon atom, respectively. ˜6 alkoxy groups, R ³ and R ⁴ may be the same or different.)

  In particular, it is preferable that the salt of the aromatic compound having a sulfo group represented by the general formula (a) and / or (b) is a lithium salt because the bronze phenomenon in the obtained image can be avoided.

  In the light cyan ink composition, the content ratio of the cyan dye and the aromatic compound having a sulfo group and / or a salt thereof is within a range of 1: 1 to 1: 5 by weight. Is preferred. When the content ratio is 1: 1 or more, there is a remarkable effect on ozone resistance. By setting the content ratio to 1: 5 or less, it is easy to ensure reliability such as clogging.

  The aromatic compound having a sulfo group represented by the general formula (a) and / or (b) and / or a salt thereof includes an aromatic compound having at least one sulfo group in the molecular structure and / or a salt thereof. As long as it has two or more sulfo groups, in particular, 1,3-benzenedisulfonic acid, naphthalene-1,5-disulfonic acid, naphthalene-1,6-disulfonic acid, naphthalene-2, At least one selected from the group consisting of 6-disulfonic acid, naphthalene-2,7-disulfonic acid, naphthalene-1,3,6-trisulfonic acid and salts thereof can improve the ozone resistance of the resulting image. This is preferable.

  The salt of the aromatic compound having a sulfo group may be added in the form of the salt and contained in the ink composition, and used for forming a salt with the aromatic compound having the sulfo group. The resulting base can be added separately and contained in the ink composition.

  Among the aromatic compounds having a sulfo group and / or salts thereof, by using an aromatic compound having three or more sulfo groups and / or a salt thereof, the discoloration of an image derived from ozone gas is suppressed, and the image It is possible to dramatically improve the fading resistance.

  Although the details of the action in the case of having three or more sulfo groups are unclear, by selectively using those having three or more sulfo groups, the water solubility of the aromatic compound can be improved. It is considered that the effect of preventing and suppressing the precipitation of the aromatic compound on the surface of the recording medium appears. As a result, it is possible to improve the gas resistance, particularly ozone resistance of the printed matter without any trouble.

  The aromatic compound having three or more sulfo groups and / or a salt thereof may be any aromatic compound having at least three sulfo groups in the molecular structure and / or a salt thereof, particularly naphthalene- 1,3,5-trisulfonic acid, naphthalene-1,3,6-trisulfonic acid, naphthalene-1,3,7-trisulfonic acid, naphthalene-1,4,6-trisulfonic acid, naphthalene-1, At least one selected from the group consisting of 4,7-trisulfonic acid and salts thereof is preferable from the viewpoint of improving the ozone resistance of the obtained image and suppressing additive precipitation. Furthermore, the lithium salt of these aromatic sulfonic acid compounds is more preferable because it works effectively in terms of suppressing bronzing of printed images.

  As described above, in the cyan ink composition or the dark cyan ink composition and the light cyan ink composition in the ink set of the present invention, the ozone resistance, light resistance, and moisture resistance are greatly increased for adjusting the color tone of the ink. Other cyan dyes can be used in combination as long as they are not impaired.

  Examples of other cyan dyes that can be used in the present invention include C.I. I. Direct Blue 1, 10, 15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80, 84, 86, 87, 90, 98, 106, 108, 109, 151, 156, 158, 159, 160, 168, 189, 192, 193, 194, 199, 200, 201, 202, 203, 207, 211, 213, 214, 218, 225, 229, 236, 237, 244, 248, 249, 251 252, 264, 270, 280, 288, 289, 291, C.I. I. Acid Blue 9,25,40,41,62,72,76,78,80,82,92,106,112,113,120,127: 1,129,138,143,175,181,205,207, 220, 221, 230, 232, 247, 258, 260, 264, 271, 277, 278, 279, 280, 288, 290, 326, C.I. I. Reactive Blue 2, 3, 5, 8, 10, 13, 14, 15, 17, 18, 19, 21, 25, 26, 27, 28, 29, 38, C.I. I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 41, 45, 46, 47, 54, 57, 60, 62, 65, 66, 69, 71, etc. Not.

  In the present invention, when the specific colorant used as the cyan ink has a concentration of 3% by weight or more in the ink, a naphthalene-based aromatic having a carboxyl group at the 2-position in the cyan ink composition It is preferable to contain at least one selected from a compound or a salt thereof. By adding at least one selected from the group consisting of a naphthalene-based aromatic compound having a carboxyl group at the 2-position and a salt thereof, the occurrence of bronzing in the cyan ink composition can be prevented. The above bronze phenomenon generally indicates that a portion of the ink composition containing a cyan dye that has been subjected to high duty printing such as solid printing on an ink jet recording medium (particularly a glossy recording medium) is reddish. Known as a phenomenon. When the bronze phenomenon occurs, the color balance of the entire image becomes non-uniform and the image quality deteriorates, so that a good image cannot be obtained.

  Among the naphthalene-based aromatic compounds having a carboxyl group at the 2-position used in the present invention, particularly preferred are alkali metal salts of naphthalene-based aromatic compounds having a carboxyl group at the 2-position. Further, among the alkali metal salts, it is particularly preferable to use a lithium salt. When lithium salt is used, not only the occurrence of the bronze phenomenon can be prevented, but also an effect that clogging of the ink jet nozzle is less likely to occur.

  Examples of the naphthalene-based aromatic compound having a carboxyl group at the 2-position or a salt thereof include 2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, and 6-hydroxy-2-naphthoic acid. 4-hydroxybenzoic acid, 2,6-naphthalenedicarboxylic acid, 3-methoxy-2-naphthoic acid, 3-ethoxy-2-naphthoic acid, 3-propoxy-2-naphthoic acid, 6-methoxy-2-naphthoic acid , 6-ethoxy-2-naphthoic acid, 6-propoxy-2-naphthoic acid, and the like, and salts thereof, particularly lithium salts. Particularly preferred are 2-naphthoic acid and its lithium salt.

  When a salt of a naphthalene aromatic compound having a carboxyl group at the 2-position is added to the ink composition, a method of adding it to the ink in the form of a salt, or a corresponding naphthalene-based aromatic compound having a carboxyl group at the 2-position And any method of adding it and the base which can form a salt separately to an ink composition can be used. Furthermore, in this invention, at least 1 type chosen from the group which consists of a naphthalene type aromatic compound which has a carboxyl group in 2-position, and its salt can be used.

  The cyan ink composition in the ink set of the present invention is selected from the group consisting of a naphthalene-based aromatic compound having a carboxyl group at the 2-position and a salt thereof (hereinafter referred to as a naphthalene-based aromatic compound having a carboxyl group at the 2-position). In the case where at least one kind is added, a naphthalene-based aromatic compound having a carboxyl group at the 2-position is preferably contained in the ink composition in an amount of 0.1 to 10% by weight, preferably 0.5 to 5%. More preferably, it is contained by weight. The amount of the naphthalene-based aromatic compound having a carboxyl group at the 2-position contained in the ink composition is the kind of itself, the kind of dye contained in the ink composition, the kind of solvent used in the ink composition, etc. The preferred amount can be determined as appropriate.

  The ratio of the amount (% by weight) of the cyan dye contained in the cyan ink composition to the amount (% by weight) of the naphthalene aromatic compound having a carboxyl group at the 2-position is 1: 0.1 to 1:10. It is preferable that the ratio is 1: 0.3 to 1: 6. When the content of the cyan dye in the cyan ink composition is 1, the occurrence of bronzing can be increased by increasing the content of a naphthalene-based aromatic carboxylic acid having a carboxyl group at the 2-position to more than 0.1. Further, by reducing the content of a naphthalene aromatic compound having a carboxyl group at the 2-position to less than 10, clogging of the ink jet nozzle can be prevented.

  Further, in order to stably dissolve a naphthalene-based aromatic compound having a carboxyl group at the 2-position in the cyan ink composition, the pH of the ink composition at 20 ° C. is preferably 8.0 or higher. The pH value of the ink composition in the present invention is a value measured by directly inserting a pH electrode into the ink composition using a commercially available pH meter.

Next, the colorant used in the two types of magenta ink compositions having different color densities in the ink set of the present invention will be described.
The magenta ink composition in the present invention contains, as a colorant, at least one compound represented by the following formula (M-1) and at least one compound represented by the following formula (M-2). To do.

ここで、前記式（Ｍ-１）中、Ａは、５員複素環ジアゾ成分Ａ−ＮＨ₂の残基を表す。Ｂ¹およびＢ²は、各々−ＣＲ¹＝、-ＣＲ²＝を表すか、あるいはいずれか一方が窒素原子，他方が−ＣＲ¹＝または−ＣＲ²＝を表す。Ｒ⁵，Ｒ⁶は、各々独立に、水素原子、脂肪族基、芳香族基、複素環基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、アルキルスルホニル基、アリールスルホニル基、またはスルファモイル基を表わす。各基は更に置換基を有していてもよい。Ｇ、Ｒ¹、Ｒ²は、各々独立して、水素原子、ハロゲン原子、脂肪族基、芳香族基、複素環基、シアノ基、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、アシル基、ヒドロキシ基、アルコキシ基、アリールオキシ基、シリルオキシ基、アシルオキシ基、カルバモイルオキシ基、ヘテロ環オキシ基、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、アルキル基またはアリール基または複素環基で置換されたアミノ基、アシルアミノ基、ウレイド基、スルフアモイルアミノ基、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、アルキルおよびアリールスルホニルアミノ基、アリールオキシカルボニルアミノ基、ニトロ基、アルキルおよびアリールチオ基、アルキルおよびアリールスルホニル基、アルキルおよびアリールスルフィニル基、スルファモイル基、スルホ基、またはヘテロ環チオ基を表す。各基は更に置換されていてもよい。また、Ｒ¹とＲ⁵、あるいはＲ¹とＲ⁵が結合して５〜６員環を形成してもよい。

Here, in the formula (M-1), A represents a residue of a 5-membered heterocyclic diazo component A-NH ₂ . B ¹ and B ² are each -CR ¹ =, - or represents a CR ² =, or either one is a nitrogen atom, the other represents -CR ¹ = or -CR ² =. R ⁵ and R ⁶ are each independently a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkylsulfonyl group, arylsulfonyl group, or Represents a sulfamoyl group. Each group may further have a substituent. G, R ¹ and R ² are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carboxyl group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, Substituted with acyl group, hydroxy group, alkoxy group, aryloxy group, silyloxy group, acyloxy group, carbamoyloxy group, heterocyclic oxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, alkyl group or aryl group or heterocyclic group Amino group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl and arylsulfonylamino group, aryloxycarbonylamino group, nitro group, alkyl and arylthio group, Alkyl and arylsulfonyl group, an alkyl- or arylsulfinyl group, a sulfamoyl group, a sulfo group, or a heterocyclic thio group. Each group may be further substituted. R ¹ and R ⁵ , or R ¹ and R ⁵ may be bonded to form a 5- to 6-membered ring.

ここで、前記式（Ｍ-２）中、Ｍは水素原子、アンモニウム基、又はアルカリ金属原子、Ｘはジアミノアルキレン基を表し、ｎは１又は２である。

Here, in the formula (M-2), M represents a hydrogen atom, an ammonium group, or an alkali metal atom, X represents a diaminoalkylene group, and n is 1 or 2.

  The light magenta ink composition used in the ink set of the present invention colors at least one compound represented by the formula (M-1) and at least one compound represented by the formula (M-2). 0.2 to 1 of at least one compound represented by the formula (M-1) with respect to the total weight of the magenta ink composition which is included as an agent and the total of the colorants has the low color density. 0.0 wt% and at least one compound represented by the above formula (M-2) is contained in an amount of 0.3 to 1.5 wt%, particularly for securing light resistance and moisture resistance. Is preferable.

  The dark magenta ink composition used in the ink set of the present invention colors at least one compound represented by the formula (M-1) and at least one compound represented by the formula (M-2). 0.6 to 2 of at least one compound represented by the formula (M-1) with respect to the total weight of the magenta ink composition which is included as an agent and the total of the colorants has the high color density. 0.5 wt% and at least one compound represented by the formula (M-2) is contained in an amount of 1.5 to 7.0 wt%, particularly in terms of color developability, light resistance and moisture resistance. It is preferable in terms of securing.

  In the light magenta ink composition, the weight ratio of the compound represented by the formula (M-1) and the compound represented by the formula (M-2) is 2: 1 to 1: 2. The range is particularly preferable in terms of securing light resistance and moisture resistance.

  In the dark magenta ink composition, the content ratio of the compound represented by the formula (M-1) and the compound represented by the formula (M-2) is 1: 1 to 1: A range of 8 is particularly preferable in terms of securing light resistance and moisture resistance.

  The magenta ink composition used in the ink set of the present invention contains at least one compound represented by the formula (M-1) as a colorant in water or an aqueous medium composed of water and a water-soluble organic solvent. And at least one compound represented by the formula (M-2), and if necessary, a moisturizer, a surfactant, a penetration enhancer, a viscosity adjuster, a pH adjuster and other additives. Is contained. By using the compound represented by the formula (M-1) and the compound represented by the formula (M-2) in combination, it has excellent light resistance, ozone resistance and moisture resistance, and is well balanced. An ink composition having the above characteristics can be provided.

  Preferred embodiments of the magenta ink composition include, as additives, betaine surfactants, antifoaming agents, carboxyl-containing aromatic compounds represented by the formulas (b-1) to (b-3) described later, and urea. Derivatives, nonionic surfactants and penetration enhancers are added singly or in combination of two or more, so that the colorant can be fixed on the recorded matter, moisture resistance, light resistance, ozone resistance, etc. There is an ink composition in which

  As the compound (magenta dye) represented by the formula (M-1) used in the present invention, one kind may be used alone, or a plurality kinds may be mixed and used.

  Among the compounds represented by the formula (M-1), a compound represented by the following formula (M-3) is preferable.

式（Ｍ-３）において、Ｒ₁〜Ｒ₅は、水素原子、アルキル基、スルホ基又はその塩を表す。式（Ｍ-３）において、Ｒ₁，Ｒ₅はそれぞれ独立に、共にアルキル基の時はそのアルキル基を構成する炭素数の合計が３以上であってそれらに置換基を有していてもよい。Ｘは水素原子、脂肪族基、芳香族基、または複素環基を表し、Ｙ及びＺは各々独立に、水素原子、脂肪族基、芳香族基、複素環基、アシル基、アルコキシカルボニル基、アリールオキシカルボニル基、カルバモイル基、アルキルスルホニル基、アリールスルホニル基、またはスルファモイル基を表す。各基は更に置換基を有していてもよい。また、Ｒ₁〜Ｒ₅にスルホ基が含まれる場合には−ＳＯ₃Ｍの形となっている。その場合、Ｍとしては、アルカリ金属原子が好ましく、より好ましくはＬｉ又はＮａである。

In formula (M-3), R _{1 to} R ₅ represent a hydrogen atom, an alkyl group, a sulfo group, or a salt thereof. In Formula (M-3), when R ₁ and R ₅ are each independently an alkyl group, the total number of carbon atoms constituting the alkyl group is 3 or more, and they may have a substituent. Good. X represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and Y and Z each independently represent a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, An aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or a sulfamoyl group is represented. Each group may further have a substituent. When R _{1 to} R ₅ contain a sulfo group, it is in the form of —SO ₃ M. In that case, M is preferably an alkali metal atom, more preferably Li or Na.

  Among the compounds represented by the formula (M-3), the compound has excellent light resistance and ozone resistance. From the viewpoint of improving moisture resistance with a betaine surfactant described later, the following formula (M− The compound represented by 4) is particularly preferred.

（前記式Ｍ-４中、Ｒ₁〜Ｒ₁₀は水素原子、アルキル基、スルホ基又はその塩を表し、（Ｒ₁，Ｒ₅）及び（Ｒ₆，Ｒ₁₀）は、それぞれ独立に、共にアルキル基を構成する炭素数の合計が３以上であってそれらに置換基を有していてもよい。また、Ｍは水素原子又はアルカリ金属原子を表す。）

(In Formula M-4, R _{1 to} R ₁₀ represent a hydrogen atom, an alkyl group, a sulfo group or a salt thereof, and (R ₁ , R ₅ ) and (R ₆ , R ₁₀ ) are each independently (The total number of carbon atoms constituting the alkyl group is 3 or more, and they may have a substituent. M represents a hydrogen atom or an alkali metal atom.)

  In the compound (magenta dye) represented by the formula (M-2) used in combination with the compound represented by the formula (M-1) as a colorant in the magenta ink composition, M is a hydrogen atom and forms a salt. Represents an ammonium group or an alkali metal atom, X represents a diaminoalkylene group, and n is 1 or 2.

  Addition of the compound represented by the general formula (M-2) particularly has an effect of improving moisture resistance. The compound represented by general formula (M-2) may be used individually by 1 type, or may use multiple types together. Among the compounds represented by the general formula (M-2), a compound having a structure where n is 2 has good moisture resistance and is particularly preferable.

In addition, the magenta ink composition may be used in combination with other magenta dyes within a range that does not significantly impair each characteristic such as light resistance, in order to adjust the color tone.
Examples of magenta dyes other than the compounds represented by formula (M-1) and formula (M-2) include C.I. I. Direct Red 2, 4, 9, 23, 26, 31, 39, 62, 63, 72, 75, 76, 79, 80, 81, 83, 84, 89, 92, 95, 111, 173, 184, 207, 211, 212, 214, 218, 221, 223, 224, 225, 226, 227, 232, 233, 240, 241, 242, 243, 247, C.I. I. Direct violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100, 101, C.I. I. Acid Red 35, 42, 52, 57, 62, 80, 82, 111, 114, 118, 119, 127, 128, 131, 143, 151, 154, 158, 249, 254, 257, 261, 263, 266 289, 299, 301, 305, 336, 337, 361, 396, 397, C.I. I. Acid Violet 5, 34, 43, 47, 48, 90, 103, 126, C.I. I. Reactive Red 3, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40, 41, 43, 45, 49, 55, C.I. I. Reactive violet 1,3,4,5,6,7,8,9,16,17,22,23,24,26,27,33,34, C.I. I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36, 38, 39, 45, 46, C.I. I. Basic violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35, 37, 39, 40, 48, etc. can be mentioned.

  In a magenta ink composition containing a compound represented by the formula (M-1) and a compound represented by the formula (M-2) as a colorant, the betaine represented by the formula (b-1) By adding a surfactant, the fixability of the colorant to the recording medium is greatly improved, the moisture resistance is improved, the light resistance and the ozone resistance are also improved, and a stable image is maintained over a long period of time. There is an effect that a recorded material can be obtained.

In the formula (b-1), R represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. L represents a divalent or higher valent linking group. M represents a hydrogen atom, an alkali metal atom, an ammonium group, a protonated organic amine or a nitrogen-containing heterocyclic group, a quaternary ammonium ion group, and a counter ion of an ammonium ion composed of an N atom in the formula (b-1) Represents a group that does not exist as a cation. q represents an integer of 1 or more, and r represents an integer of 1 to 4. p represents an integer of 0 or more and 4 or less, and p + r is 3 or 4. When p + r is 4, N is a nitrogen atom constituting a quaternary amine. When p is 2 or more, R may be the same or different. When q is 2 or more, the COOMs may be the same or different. When r is 2 or more, L- (COOM) _q may be the same or different.

Among the betaine surfactants represented by the formula (b-1), the betaine surfactants represented by the formula (b-2) from the viewpoint of improving the fixability of the ink composition to the recording medium. Is preferred. In formula (b-2), R _{1 to} R ₃ represent an alkyl group having 1 to 20 carbon atoms, and X represents a divalent linking group. In particular, the betaine surfactant represented by the above formula (b-3) is preferable because it has a large effect of improving the fixability of the ink composition to a recording medium. The betaine surfactant represented by the formula (b-1) may be used alone or in combination of two or more.

  The addition effect of the betaine-based surfactant represented by the formula (b-1) mainly suppresses a decrease in moisture resistance derived from the compound represented by the formula (M-1), and enables the recording medium of the colorant. The content ratio of the compound represented by the formula (M-1) and the betaine surfactant represented by the formula (b-1) is 1 by weight. : It is preferable to set it as the range of 3-3: 1, More preferably, it is the range of 1: 2 to 2: 1. By making the content ratio of the compound represented by the formula (M-1) and the betaine surfactant in this range, it is possible to obtain a remarkable improvement effect of the fixing property of the colorant to the recording medium.

As described above, the betaine surfactant represented by the formula (b-1) has a large effect of improving the properties of the ink composition, particularly an improvement effect of the fixing property, but has a high foaming property. Depending on the combination with the additive, the foamability of the ink composition is increased, the load on the ink system is increased, and the system construction may be expensive.
Therefore, when adding a betaine surfactant having the above structure, it is preferable to add a specific antifoaming agent.
In the magenta ink composition, the antifoaming agent used in combination with the betaine surfactant is preferably an aliphatic diol compound having a carbon number of 4 to 6 and a hydroxyl value of 2, or a diacetylenetetraol compound.

  Examples of the aliphatic diol compound having 4 to 6 carbon atoms and 2 hydroxyl value include 1,4-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, and the like. Among them, 1,2-hexanediol is preferable among them. Moreover, as a diacetylene tetraol type compound, Surfynol MD20 etc. which can be obtained as a commercial item, for example, Air Products are mentioned.

If the amount of the antifoaming agent is too small, the defoaming effect of the ink composition will be insufficient, and if it is too large, the printing quality and storage stability will be impaired. For this reason, in this invention, it is preferable to make it contain in 0.05-10.0 wt% in an ink composition, More preferably, it is 0.1-5.0 wt%.
In addition, by setting the content ratio of the antifoaming agent and the betaine surfactant represented by the formula (b-1) in the range of 1:10 to 4: 1 by weight, the ink composition is used. As a whole, it is possible to obtain a well-balanced ink composition that is excellent in foam suppression and defoaming effects and excellent in printing stability.

  In the present invention, at least one selected from an aromatic compound having a carboxyl group and a salt thereof may be used in order to improve moisture resistance and improve fixability of a colorant to a recording medium. Any aromatic compound or salt thereof having at least one carboxyl group in the molecular structure may be used, but one having one carboxyl group is preferable, and one having a naphthalene skeleton is preferable. Further, a compound having a carboxyl group at the 2-position and having a naphthalene skeleton or a salt thereof is more preferable, and a more preferable one is an alkali metal salt of a compound having a carboxyl group at the 2-position and having a naphthalene skeleton. . Among alkali metal salts of compounds having a carboxyl group at the 2-position and having a naphthalene skeleton, lithium salts are preferred from the viewpoint of clogging resistance.

Specific examples of the aromatic compound having a carboxyl group or a salt thereof include 2-hydroxy-1-naphthoic acid, 1-hydroxy-2-naphthoic acid, 1-naphthoic acid, 2-naphthoic acid, 3-hydroxy- 2-naphthoic acid, 6-hydroxy-2-naphthoic acid, 3-methoxy-2-naphthoic acid, 6-methoxy-2-naphthoic acid, 6-ethoxy-2-naphthoic acid, 6-propoxy-2-naphthoic acid, Examples thereof include 4-hydroxybenzoic acid, 2,6-naphthalenedicarboxylic acid, and salts thereof (particularly lithium salts).
The salt of the aromatic compound having a carboxyl group is added in the form of a salt and can be contained in the ink. In addition, the aromatic compound having a carboxyl group and the base are added separately, It is also possible to contain.

The content of at least one kind selected from these aromatic compounds having a carboxyl group and a salt thereof is the kind of aromatic compound having a carboxyl group and / or a salt thereof, the kind of colorant, the kind of solvent component, other Although it is determined depending on the additive and the like, it is preferably in the range of 0.1 to 10 wt%, more preferably 0.5 to 5 wt% with respect to the total weight of the ink composition.
The content ratio of at least one selected from the compound represented by the formula (M-1), the aromatic compound having a carboxyl group, and a salt thereof is in the range of 5: 1 to 1: 3 by weight ratio. It is preferable that there is a range of 3: 1 to 1: 2. By making the content ratio higher than 5: 1, a sufficient effect of improving moisture resistance can be obtained, and by making the content ratio lower than 1: 3, clogging resistance (clogging reliability) can be easily secured. .

Adding a urea derivative to the magenta ink composition has an effect of improving light resistance.
Examples of urea derivatives that can be used in the present invention include urea, allyl urea, dimethylol urea, malonyl urea, carbamyl urea, n-butyl urea, dibutyl urea, N, N-dimethyl urea, 1,3-dimethyl urea, and N-methyl urea. , Hydroxyurea, ethylurea, methylurea, creatinine, 2-imidazolidinone, benzylurea, (R)-(+)-1-phenylethylurea, phenylurea, 3-hydroxyphenylurea, 1-phenylsemicarbazide, 4 -Phenyl semicarbazide, N-benzoylurea, N, N'-O-phenyleneurea and the like can be mentioned, and one of these can be used alone, or two or more can be used in combination.

  The content of the urea derivative is preferably in the range of 0.5 to 20 wt%, more preferably in the range of 1 to 16 wt%, and still more preferably in the range of 2 to 12 wt% with respect to the total weight of the ink composition. By making the content 0.5 wt% or more, the effect of improving light resistance by adding the urea derivative becomes clear, and by making the content 20 wt% or less, the reliability such as clogging property can be kept good. it can.

  In the magenta ink composition, the content ratio of the compounds represented by the formulas (M-1) and (M-2) and the urea derivative is preferably in the range of 5: 1 to 1:10 by weight ratio. More preferably, it is in the range of 4: 1 to 1: 8, and still more preferably in the range of 3: 1 to 1: 5. By setting the ratio between the two in this range, it is possible to achieve high light resistance and secure characteristics in terms of reliability.

  In order to stably dissolve the colorant, betaine surfactant, carboxyl-containing aromatic compound, urea derivative and the like, the pH (20 ° C.) of the ink composition is preferably 8.0 or more. . In consideration of material resistance with various members in contact with the ink composition, the pH of the ink composition is preferably 10.5 or less. In order to make these matters better compatible, it is more preferable to adjust the pH of the ink composition to 8.5 to 10.0.

Next, the colorant used in the yellow ink composition constituting the ink set of the present invention will be described.
In the ink set of the present invention, the yellow ink composition contains at least one compound represented by the following formula (Y-1) as a colorant.

（上記式中、Ｘ₁、Ｘ₂、Ｙ₁、及びＹ₂は水素原子、又はシアノ基を表し、Ｚ₁及びＺ₂は芳香環を有する置換基を表し、Ｒ₁及びＲ₂はアルキル基を表し、Ｍは金属原子を表す。）

(In the above formula, X ₁ , X ₂ , Y ₁ , and Y ₂ represent a hydrogen atom or a cyano group, Z ₁ and Z ₂ represent a substituent having an aromatic ring, and R ₁ and R ₂ represent an alkyl group. And M represents a metal atom.)

  In particular, the compound represented by the formula (Y-1) is preferably a compound represented by the following formula (Y-2) from the viewpoint of improvement in light resistance and ozone resistance.

（上記式中、Ｘ₁、Ｘ₂、Ｙ₁、及びＹ₂は水素原子、又はシアノ基を表し、Ｗ₁〜Ｗ₅及びＷ₁₁〜Ｗ₁₅は、それぞれ水素原子、カルボキシル基又はその塩を表し、Ｍは金属原子を表し、ｔ−Ｂｕはターシャリーブチル基を表す。）

(In the above formula, X ₁ , X ₂ , Y ₁ , and Y ₂ represent a hydrogen atom or a cyano group, and W _{1 to} W ₅ and W _{11 to} W ₁₅ represent a hydrogen atom, a carboxyl group, or a salt thereof, respectively. M represents a metal atom, and t-Bu represents a tertiary butyl group.)

  The yellow ink composition further contains at least one compound represented by the following formula (Y-3) as a colorant to make the ozone resistance characteristics of the magenta ink composition and the cyan ink composition equivalent. It is preferable in that it can be performed.

（上記式中、Ｒはメトキシ基又はメチル基を表し、Ａは１，５−ジスルフォナフト−３−イル又は１，５，７−トリスルフォナフト−２−イルを表す。）

(In the above formula, R represents a methoxy group or a methyl group, and A represents 1,5-disulfonaft-3-yl or 1,5,7-trisulfonaft-2-yl.)

  Furthermore, in the present invention, in order to adjust the color tone of the yellow ink composition, other yellow dyes can be used in combination as long as the ozone resistance, light resistance and moisture resistance are not significantly impaired.

  In the present invention, the concentration of the colorant contained in the yellow ink composition can be appropriately determined according to the color value of the compound (dye) used as the colorant, but the total amount of the colorant is determined according to the yellow ink composition. The content is preferably 1.0 to 7.0% by weight based on the total weight of the yellow ink composition. By setting the concentration of the total amount of the colorant contained in the yellow ink composition to 1.0% by weight or more, good color developability can be obtained, and the concentration of the total amount of the colorant is set to 7.0. By setting it to not more than% by weight, it is possible to improve the characteristics such as ejection properties from the nozzles required as an ink composition for use in the ink jet recording method, and to prevent clogging of the ink nozzles.

Next, the colorant used in the black ink composition constituting the ink set of the present invention will be described.
The ink set of the present invention can be configured to contain a black ink composition as desired. By including the black ink composition in the ink set of the present invention, an image having good contrast can be formed on a recording medium.

  The black ink composition contains a colorant represented by the following formula (Bk-1), and may contain a surfactant, a penetration enhancer, and other additives as necessary. Moreover, the coloring agent represented by a following formula (Bk-1) may be used individually by 1 type, and 2 or more types may be mixed and used for it.

（式（Bｋ-１）中、Ａ₁は下記式（Bｋ-２）又は（Bｋ-３）で表される置換基であり、Ａ₂は下記式（Bｋ-４）又は（Bｋ-５）で表される置換基であり、Ａ₃は下記式（Bｋ-６）で表される置換基である。）

(In the formula (Bk-1), A ₁ is a substituent represented by the following formula (Bk-2) or (Bk-3), and A ₂ is the following formula (Bk-4) or (Bk-5). And A ₃ is a substituent represented by the following formula (Bk-6).)

（式（Bｋ-２）中、ＭはＬｉ又はＮａを表す。）

(In the formula (Bk-2), M represents Li or Na.)

（式（Bｋ-３）中、ＭはＬｉ又はＮａを表す。）

(In the formula (Bk-3), M represents Li or Na.)

（式（Bｋ-６）中、ＭはＬｉ又はＮａを表す。）

(In the formula (Bk-6), M represents Li or Na.)

Specifically, as the colorant represented by the formula (Bk-1), specifically, the following formula (Bk-1) in which A _{1 to} A ₃ in the formula (Bk-1) are combined as shown in Table 1 -1), a formula (Bk-1-2), a formula (Bk-1-3), and a colorant as shown in formula (Bk-1-4). These colorants may be used alone or in combination of two or more.

表１中、ＭはＬｉ又はＮａを示す。

In Table 1, M represents Li or Na.

  The black ink composition can further improve color developability (optical density) on non-glossy media (matte paper or plain paper) by containing a colorant represented by the following formula (Bk-7). Is preferable. Only one colorant represented by the following formula (Bk-7) may be used alone, or two or more colorants may be mixed and used.

（式（Bｋ-７）中、Ｒ₁は、ハロゲン原子、Ｈ、ＳＯ₃Ｍ、ＣＯＯＭのいずれかを示し、Ｒ₂及びＲ₃はそれぞれ独立に、Ｈ、ＳＯ₃Ｍ、ＣＯＯＭのいずれかを示し、Ｍは、Ｌｉ又はＮａを示す。ただし、Ｒ₂及びＲ₃がいずれもＨである場合はない。）

(In the formula (Bk-7), R ₁ represents a halogen atom, H, SO ₃ M, or COOM, and R ₂ and R ₃ independently represent any of H, SO ₃ M, or COOM. M represents Li or Na, provided that R ₂ and R ₃ are not H.)

  Specific examples of the colorant represented by the formula (Bk-7) include the following formula (Bk-7-1), formula (Bk-7-2), and formula (Bk-7-3). Colorants as shown are mentioned. These colorants may be used alone or in combination of two or more.

（式Bｋ-７-１中、Ｍは、Ｌｉ又はＮａを示す。ただし、全てのＭがＮａとなることはない。）

(In the formula Bk-7-1, M represents Li or Na. However, not all M is Na.)

（式Bｋ-７-２中、Ｍは、Ｌｉ又はＮａを示す。ただし、全てのＭがＮａとなることはない。）

(In formula Bk-7-2, M represents Li or Na. However, not all M is Na.)

（式Bｋ-７-３中、Ｍは、Ｌｉ又はＮａを示す。ただし、全てのＭがＮａとなることはない。）

(In the formula Bk-7-3, M represents Li or Na. However, not all M is Na.)

  When the colorant represented by the formula (Bk-1) and the colorant represented by the formula (Bk-7) are used in combination, the colorant represented by the formula (Bk-1) and the formula (Bk-7) Although it does not restrict | limit especially as a compounding ratio with the coloring agent represented, It is preferable that it is 2: 1 to 1: 2 by weight ratio. In addition, if the blending ratio of the colorant represented by the formula (Bk-1) is excessively large, coloring on the mat paper may be inferior, and the blending ratio of the colorant represented by the formula (Bk-7) is If the amount is too large, the ozone resistance may be inferior, or the bronze phenomenon may easily occur.

  Further, the sum of the content of the colorant represented by the formula (Bk-1) and the content of the colorant represented by the formula (Bk-7) is 5 to 8 wt% in the black ink composition. %, Particularly 5 to 7% by weight. Within this range, the color development of the recorded image can be ensured and the occurrence of bronzing can be suppressed.

  Further, the black ink composition has a bronze phenomenon suppressing effect by adding a colorant represented by the following formula (Adj-1), and a black color having a hue close to an achromatic color even in an intermediate duty. An ink composition can be obtained.

（式（Adj-１）中、ＭはＬｉ又はＮａを表す。）

(In the formula (Adj-1), M represents Li or Na.)

  Specific examples of the colorant represented by the formula (Adj-1) include colorants as shown in the following formulas (Adj-1-1) and (Adj-1-2).

  As a ratio between the total amount of the colorant represented by the formula (Bk-1) and the colorant represented by the formula (Bk-7) and the amount of the colorant represented by the formula (Adj-1) Is preferably 4: 1 to 7: 1 by weight from the viewpoint of securing the hue.

In addition to the colorant represented by the above formula (Adj-1), C.I. I. By adding Direct Yellow 86, it becomes easier to bring the hue closer to an achromatic color compared to the case where only the colorant represented by the formula (Adj-1) is added, and the hue is adjusted with higher accuracy. be able to.
The total amount of the colorant represented by the formula (Bk-1) and the colorant represented by the formula (Bk-7), the colorant represented by the formula (Adj-1), and C.I. I. The ratio of the total amount of Direct Yellow 86 is preferably 3: 1 to 5: 1 by weight from the viewpoint of securing the hue.

  The colorant used in each ink composition in the ink set of the present invention and the content of the colorant in the ink composition have been described above. Hereinafter, other components included in each ink composition will be described.

  Each ink composition in the present invention can be obtained by dissolving the above-described colorant (dye) in an appropriate solvent. As a solvent for dissolving the colorant in each ink composition, water or a mixed liquid of water and a water-soluble organic solvent is preferably used as a main solvent. As water, ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or the like can be used. From the viewpoint of long-term storage, it is preferable to use water that has been subjected to various chemical sterilization treatments such as ultraviolet irradiation and addition of hydrogen peroxide. The water content in each ink composition constituting the ink set of the present invention is preferably 40 to 90% by weight, more preferably 50 to 80% by weight of the ink composition.

  As described above, each ink composition in the present invention can use a water-soluble organic solvent as a solvent together with water. As the water-soluble organic solvent, those having the ability to dissolve the dye are preferable, and those having a vapor pressure smaller than that of pure water are preferable.

  Examples of the water-soluble organic solvent used in the present invention include ethylene glycol, propylene glycol, butanediol, pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, glycerin, 1, Polyhydric alcohols such as 2,6-hexanetriol, diethylene glycol, triethylene glycol and dipropylene glycol, ketones such as acetonylacetone, esters such as γ-butyrolactone and triethyl phosphate, furfuryl alcohol, tetrahydrofurfuryl Although alcohol, thiodiglycol, etc. are preferable, it is not limited to these. By using a water-soluble organic solvent together with water as the solvent of the ink composition, the ejection stability of the ink composition from the ink head can be improved, and the viscosity of the ink composition can be lowered with almost no other change. Etc. can be easily adjusted.

  Further, at least one humectant selected from saccharides can be contained in each ink composition of the present invention. By including a moisturizing agent in the ink composition, when the ink composition is used in the ink jet recording method, it is possible to suppress moisture evaporation from the ink and moisturize the ink. As the saccharide used in the present invention, maltitol, sorbitol, gluconolactone, maltose and the like are preferable. In addition, the water-soluble organic solvent mentioned above may work as a moisturizer.

  The water-soluble organic solvent and / or humectant can be contained in the ink composition in a total amount of 5 to 50% by weight, more preferably 5 to 30% by weight, and particularly preferably 5 to 20% by weight. By making these contents 5% by weight or more, good ink moisture retention can be obtained, and by making it 50% by weight or less, the viscosity of the ink composition is adjusted to a preferred viscosity for use in the ink jet recording method. can do.

  Other preferable additives to be added to the ink composition constituting the ink set of the present invention will be described below.

  The ink composition constituting the ink set of the present invention preferably contains a nonionic surfactant. By adding a nonionic surfactant, the penetrability of the ink composition into the recording medium is improved, and the ink composition can be quickly fixed on the recording medium during printing. Further, it is preferable that one dot recorded by the ink composition on the recording medium is as close to a perfect circle as possible. However, by containing a nonionic surfactant in the ink composition, an image formed by one dot It is possible to increase the roundness and improve the image quality of the obtained image.

  As a nonionic surfactant that can be used in the present invention, for example, an acetylene glycol-based surfactant is preferable, but is not limited thereto. As the acetylene glycol surfactant used in the ink composition of the invention, in particular, the following formula (a-1):

（式（ａ-１）中、Ｒ¹、Ｒ²、Ｒ³、及びＲ⁴はそれぞれ独立して、Ｃ１〜Ｃ６の直鎖、環式又は分枝アルキル鎖を表し、さらにＡ¹Ｏ及びＡ²Ｏはそれぞれ独立してＣ２〜Ｃ３のオキシアルキレン鎖、例えばオキシエチレン若しくはオキシプロピレン、又はＣ２〜Ｃ３のアルキレンオキサイドが重合又は共重合して得られるポリオキシアルキレン鎖、例えばポリオキシエチレン鎖、ポリオキシプロピレン鎖、若しくはポリオキシエチレンプロピレン鎖を表す。また式中、ｎ及びｍはＡ¹Ｏ又はＡ²Ｏ単位、すなわちオキシアルキレンの繰り返し数を表し、０≦ｎ＜３０、０≦ｍ＜３０、及び０≦ｎ＋ｍ＜５０を満たす数である。）
で表される化合物を用いることが好ましい。このアセチレングリコール系界面活性剤としては、例えば、サーフィノール４６５（商標）、サーフィノール１０４（商標）（以上商品名、Air Products and Chemicals Inc.製）、オルフィンＰＤ００１（商標）、オルフィンＥ１０１０（商標）（以上商品名、日信化学工業株式会社製）を例示することができ、これらから選ばれる少なくとも一種を本発明のインクセットを構成するインク組成物に添加することが好ましい。

(In Formula (a-1), R ¹ , R ² , R ³ , and R ⁴ each independently represent a C1-C6 straight chain, cyclic, or branched alkyl chain, and A ¹ O and A ² O is each independently a C2-C3 oxyalkylene chain, such as oxyethylene or oxypropylene, or a polyoxyalkylene chain obtained by polymerization or copolymerization of C2-C3 alkylene oxide, such as a polyoxyethylene chain, a polyoxyethylene chain, Represents an oxypropylene chain or a polyoxyethylenepropylene chain, wherein n and m represent A ¹ O or A ² O units, that is, the number of repeating oxyalkylenes, and 0 ≦ n <30, 0 ≦ m <30 And 0 ≦ n + m <50.)
It is preferable to use the compound represented by these. Examples of the acetylene glycol-based surfactant include Surfynol 465 (trademark), Surfynol 104 (trademark) (trade name, manufactured by Air Products and Chemicals Inc.), Olfine PD001 (trademark), Olfine E1010 (trademark). (The above-mentioned trade name, manufactured by Nissin Chemical Industry Co., Ltd.) can be exemplified, and it is preferable to add at least one selected from these to the ink composition constituting the ink set of the present invention.

  In the present invention, the nonionic surfactant is contained in the ink composition so that the nonionic surfactant is preferably contained in the ink composition in an amount of 0.1 to 5% by weight, more preferably 0.5 to 2% by weight. An agent should be added. By including 0.1% by weight or more of a nonionic surfactant in the ink composition, the penetrability of each ink composition with respect to the recording medium can be increased. Further, by making the content of the nonionic surfactant in the ink composition 5% by weight or less, an effect that an image formed with the ink composition on the recording medium is difficult to blur can be obtained.

  Furthermore, in addition to nonionic surfactants, the addition of glycol ethers as penetration enhancers to the ink composition improves the penetrability of the ink composition with respect to the recording medium, and when color printing is performed. At the boundary between adjacent color inks, ink bleeding (bleeding) is reduced, and a very clear image can be obtained. Therefore, it is preferable to add a penetration enhancer to the ink composition constituting the ink set of the present invention.

  The glycol ethers used in the present invention as penetration enhancers include ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene Glycol monobutyl ether, triethylene glycol monobutyl ether and the like are preferable, but are not limited thereto. These glycol ethers are preferably contained in the ink composition in an amount of 3 to 30% by weight, more preferably 5 to 15% by weight. By making the addition amount of glycol ethers 3% by weight or more, bleeding between adjacent inks during color printing can be effectively prevented, and by making this addition amount 30% by weight or less, image It becomes easy to prevent the occurrence of bleeding, and the storage stability of the ink can be improved.

  Further, the ink composition of the present invention includes a pH adjuster such as triethanolamine or alkali metal hydroxide, a water-soluble polymer such as sodium alginate, a water-soluble resin, a fluorosurfactant, an antiseptic, and an antifungal agent. A material selected from a rust inhibitor, a dissolution aid, an antioxidant, an ultraviolet absorber, and the like can be added as desired. These components can be used alone or in combination of two or more. Moreover, it is not necessary to add, if it is not necessary to add. Those skilled in the art can use the preferable additive selected in a preferable amount as long as the effects of the present invention are not impaired. The dissolution aid is an additive for dissolving the insoluble matter and keeping the ink composition in a uniform solution when the insoluble matter is precipitated from the ink composition.

  Examples of the solubilizer include pyrrolidones such as N-methyl-2-pyrrolidone and 2-pyrrolidone, ureas such as urea, thiourea and tetramethylurea, allophanates such as allohanate and methyl allophanate, biuret and dimethylbiuret. And biurets such as tetramethylbiuret can be mentioned, but the invention is not limited to these. Moreover, as an example of the said antioxidant, although L-ascorbic acid and its salt etc. can be illustrated, it is not limited to these.

  Examples of the antiseptic or antifungal agent include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, and 1,2-dibenzisothiazoline-3. -ON (Avexia Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN (trade name) and the like can be exemplified, but not limited thereto.

  Examples of the pH adjuster include amines such as diethanolamine, triethanolamine, propanolamine, morpholine, and modified products thereof, metal hydroxides such as potassium hydroxide, sodium hydroxide, lithium hydroxide, ammonium hydroxide, Examples thereof include ammonium salts such as quaternary ammonium hydroxide (tetramethylammonium, etc.), carbonates such as potassium carbonate, sodium carbonate, lithium carbonate, and other phosphates, but are not limited thereto.

  The ink composition constituting the ink set of the present invention is prepared by including components appropriately selected from the above-mentioned components, but the viscosity of the obtained ink composition is preferably less than 10 mPa · s at 20 ° C. . Furthermore, in the present invention, the surface tension of the ink composition is preferably 45 mN / m or less at 20 ° C., and particularly preferably in the range of 25 to 45 mN / m. By adjusting the viscosity and the surface tension in this way, an ink composition having desirable characteristics for use in the ink jet recording method can be obtained. The adjustment of the viscosity and the surface tension can be performed by appropriately adjusting and selecting the addition amount of the solvent and various additives to be contained in the ink composition, the kind thereof, and the like.

  The ink composition constituting the ink set of the present invention preferably has a pH of 7.0 to 10.5 at 20 ° C., more preferably 7.5 to 10.0. By making the pH of the ink composition at 20 ° C. 7.0 or more, it is possible to prevent the eutectoid plating of the ink jet head from being peeled off, and to stabilize the ejection characteristics of the ink composition from the ink jet head. Can do. In addition, by setting the pH of the ink composition to 10.5 or less at 20 ° C., it is possible to prevent deterioration of various members that come into contact with the ink composition, for example, members constituting an ink cartridge or an inkjet head. .

  As a method for preparing the ink composition in the present invention, for example, various components contained in the ink composition are sufficiently mixed and dissolved as uniformly as possible, followed by pressure filtration with a membrane filter having a pore size of 0.8 μm, and further. Although the method of preparing the obtained solution by deaeration using a vacuum pump can be illustrated, it is not limited to this.

  Next, the ink set of the present invention using the above-described ink composition can be used as an ink cartridge containing these integrally or independently, and is preferable from the viewpoint of convenient handling. An ink cartridge including an ink set is known in the art, and can be formed into an ink cartridge by appropriately using a known method.

  The ink set or ink cartridge of the present invention can be used for general writing instruments, recorders, pen plotters, and the like, but is particularly preferably used for an ink jet recording method. The ink jet recording method in which the ink set or the ink cartridge of the present invention can be used includes any recording method in which the ink composition is ejected as droplets from a thin nozzle and the droplets are attached to a recording medium. Specific examples of the ink jet recording method in which the ink composition of the present invention can be used will be described below.

  The first method is a method called an electrostatic attraction method. In the electrostatic suction method, a strong electric field is applied between the nozzle and the acceleration electrode arranged in front of the nozzle, and droplet-like ink is continuously ejected from the nozzle, and the ink droplet passes between the deflection electrodes. In the meantime, by supplying a printing information signal to the deflection electrode, the ink droplets are blown toward the recording medium and the ink is fixed on the recording medium, or the image is recorded, or the ink droplets are not deflected, In this method, an image is fixed on a recording medium by ejecting ink droplets from a nozzle onto the recording medium in accordance with a print information signal. The ink set or ink cartridge of the present invention is preferably used in a recording method using this electrostatic suction method.

  The second method is a method for forcibly ejecting ink droplets from the nozzles by applying pressure to the ink liquid with a small pump and mechanically vibrating the ink jet nozzles with a quartz vibrator or the like. The ink droplet ejected from the nozzle is charged at the same time as it is ejected, and while the ink droplet passes between the deflection electrodes, a print information signal is given to the deflection electrode to fly the ink droplet toward the recording medium, This is a method for recording an image on a recording medium. The ink set or ink cartridge of the present invention is preferably used for this recording method.

  The third method is a method in which an image is recorded on a recording medium by simultaneously applying a pressure and a printing information signal to the ink liquid by a piezoelectric element, and ejecting ink droplets from a nozzle toward the recording medium. The ink set or ink cartridge of the present invention is preferably used for this recording method.

  In the fourth method, the ink liquid is heated and foamed using microelectrodes according to the print signal information, and the bubbles are expanded to eject the ink liquid from the nozzle toward the recording medium, thereby forming an image on the recording medium. It is a method of recording. The ink set or ink cartridge of the present invention is preferably used for this recording method.

  The ink set or ink cartridge of the present invention is particularly preferable as an ink composition used when an image is recorded on a recording medium using an image recording method based on an ink jet recording method including the four methods described above. The recorded matter recorded using the ink set or ink cartridge of the present invention has excellent image quality, and is excellent in ozone resistance, light resistance and moisture resistance.

〔Example〕
EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the following examples.

[Preparation of each ink composition]
Based on the composition shown in Table 2 below, each component was mixed and stirred at room temperature for 30 minutes, and then the resulting solution was filtered using a membrane filter having a mesh opening of 1.0 μm to prepare each ink composition. Obtained. In Table 2, the numerical value of each component indicates the weight percent of each component when the mass of the ink composition is 100%, and the “residue” indicating the amount of water is combined with the components other than water. The amount is 100% in total.

  In Table 2, C is a cyan ink composition, M is a magenta ink composition, Y is a yellow ink composition, LC is a light cyan ink composition, LM is a light magenta ink composition, and K is a black ink composition. Represent.

  In Table 2, Cyan (Cyan) dyes 1 and 2 are examples of the compound represented by the formula (C-1), and the following formula (A):

And Z1 to Z4 in Cyan dyes 1 and 2 are those shown in Table 3 below.

  As Cyan dyes other than the compound represented by the formula (C-1) which is a Cyan dye according to the present invention, C.I. I. Direct Blue 199 (C.I. Direct Blue 199) was used.

  In Table 2, Magenta dye 1 is an example of a compound represented by the formula (M-2), and has the following formula (B):

It is a compound represented by these. In the formula (B), M represents NH ₄ or Na, and NH ₄ : Na = 1: 1 (molar ratio).

  Magenta dye 2 is an example of a compound represented by the formula (M-1), and has the following formula (C):

And R _{1 to} R ₄ in Magenta dye 2 are groups shown below, respectively.

  Magenta dye 3 is an example of a compound represented by the formula (M-4), and has the following formula (D):

It is a compound represented by these.

  In addition, as the Magenta dye other than the compound represented by the formula (M-1) or (M-2) which is the Magenta dye according to the present invention, C.I. I. Direct Red 227 (C.I. Direct Red 227) and Magenta dye 4 represented by the following formula (E) were used.

In formula (E), M represents NH ₄ or Na, and NH ₄ : Na = 1: 1 (molar ratio).

  In Table 2, Yellow (Yellow) Dye 1 is an example of a compound represented by Formula (Y-2), and has the following Formula (F):

It is a compound represented by these.

  Yellow dye 2 is an example of a compound represented by the above formula (Y-3), and has the following formula (G):

M represents Li or Na, and Li: Na = 4: 1 (molar ratio).

  In addition, as yellow dyes other than the compound represented by the formula (Y-1) which is a yellow dye according to the present invention, C.I. I. Direct Yellow 173 (C.I. Direct Yellow 173) and C.I. I. Direct Yellow 86 (C.I. Direct Yellow 86) was used.

  In Table 2, Black dye 1 is an example of a compound represented by the formula (Bk-1), and has the following formula (H):

And A _{1 to} A ₃ in Black Dye 1 are groups shown below.

  Black dye 2 is an example of a compound represented by the formula (Bk-7), and has the following formula (I):

Wherein M represents Li or Na. However, not all M becomes Na.

  Furthermore, as a black dye other than the compound represented by the formula (Bk-1) or (Bk-7) which is a black dye according to a preferred embodiment of the present invention, C.I. I. Direct Black 195 (C.I. Direct Black 195) was used.

  In addition, as a dye for color tone adjustment in a black ink composition, C.I. I. Direct Yellow 86 (C.I. Direct Yellow 86) and the following formula (J):

Yellow dye 3 (corresponding to the compound represented by the formula (Adj-1-1)) was used.

  Furthermore, the magenta ink composition in the ink set according to a preferred embodiment of the present invention contains, as a betaine surfactant, the following formula (K):

1 (corresponding to the compound represented by the formula (b-3)) was used.

  Furthermore, sodium 1,5-naphthalenedisulfonate was used as the aromatic compound having a sulfonic acid group used in the light cyan ink composition in the ink set according to a preferred embodiment of the present invention.

  Next, each ink set of Examples 1-8 and Comparative Examples 1-8 was created with the combination shown in Table 6 using each prepared ink composition. In the table, Light Magenta represents a light magenta ink composition, and Light Cyan represents a light cyan ink composition.

  Using an inkjet printer PM-G820 (registered trademark) (trade name, manufactured by Seiko Epson Corporation) and further using the ink set shown in Table 6, an inkjet-dedicated recording medium <photographic paper (gloss): model number KA420PSK; product Name, made by Seiko Epson Corporation>, yellow, magenta, cyan, and black (however, black is included only when the ink set includes a black ink composition), and the OD value of each color is 0.9 to 1 A recorded material was created by printing a solid image adjusted to be .1. The obtained recorded matter was subjected to the following ozone resistance test.

[Ozone resistance test method]
Using an ozone weather meter OMS-H type (trade name, manufactured by Suga Test Instruments Co., Ltd.), the recorded material was exposed to ozone at a concentration of 20 ppm under the conditions of 24 ° C. and 60% RH. The OD value of each color recorded on each printed matter was measured by using a densitometer (Spectrolino (registered trademark)) (manufactured by Gretag) at every elapse of a certain time from the start of exposure. The measurement conditions were a light source of D50 and a viewing angle of 2 degrees. Further, the measurement was performed for each color using Red for cyan, Green for magenta, and Blue for yellow, and no filter for black. From the results obtained, the following formula:
ROD (%) = (D / D ₀ ) × 100
(In the formula, D represents the OD value after the exposure test, and D ₀ represents the OD value before the exposure test.)
Was used to determine the residual optical density (ROD).

  Furthermore, based on the results of the above test, the ozone resistance of each color recorded on the recorded material was ranked A to F using the following criteria.

[Criteria]
Evaluation A: ROD does not decrease to 70% by 40 hours.
Evaluation B: ROD decreases to 70% over 32 hours and 40 hours or less.
Evaluation C: ROD decreases to 70% over 24 hours and 32 hours or less.
Evaluation D: ROD decreases to 70% over 16 hours and 24 hours or less.
Evaluation E: ROD decreases to 70% over 8 hours and 16 hours or less.
Evaluation F: ROD decreases to 70% within 8 hours.

  In the present invention, a recorded matter with little decrease in ROD even when exposed to ozone for a long time is excellent. The results obtained are shown in Table 7.

  In addition, from the results of the ozone resistance test for each color, the following criteria were used to rank the ozone resistance of each ink set.

[Criteria]
Evaluation A: The ozone resistance test results are all A for three colors (four colors when black is included).
Evaluation B: The ozone resistance test result is one or more of three colors (four colors when black is included) and B rank ink exists.
Evaluation C: Ink resistance test result is one or more of 3 colors (4 colors when black is included) and C rank ink exists.
Evaluation D: One or more of three colors (four colors when black is included) of ozone resistance test results and D rank ink exists.
Evaluation E: E-rank ink is present in one or more of three colors (four colors when black is included) as an ozone resistance test result.
Evaluation F: As for the ozone resistance test result, ink of F rank is present in one or more of three colors (four colors when black is included).

  In this evaluation, the evaluation A is the best, and then the evaluation B is excellent. The obtained results are shown in Table 7 as “ozone resistance (ozone resistance) of ink set”.

  Furthermore, each recorded matter was evaluated using the following criteria for each ink set for the difference (balance) in ROD change between the colors of the printed matter caused by exposure to ozone.

[Criteria]
Evaluation A: Even after 40 hours from the start of the test, the difference between the maximum value and the minimum value in the ROD of each color (hereinafter simply referred to as “ROD difference” in the description of the evaluation method) is less than 15 points.
Evaluation B: The difference in ROD becomes 15 points within 32 to 40 hours after the start of the test.
Evaluation C: The difference in ROD becomes 15 points within 24 to 32 hours from the start of the test.
Evaluation D: The difference in ROD becomes 15 points within 16 to 24 hours from the start of the test.
Evaluation E: The ROD difference becomes 15 points within 8 to 16 hours after the start of the test.
Evaluation F: The difference in ROD becomes 15 points within 8 hours from the start of the test.

  In this evaluation, a small ROD difference is excellent as a recorded matter. Table 7 shows the evaluation results obtained as “ozone resistance (color balance) of ink set”.

[Fluorescent light resistance test method]
For the ink set shown in Table 6, the recorded material used in the ozone resistance test was recreated, and a fluorescent light resistance tester SFT-III type (trade name, manufactured by Suga Test Instruments Co., Ltd.) was used. The recorded matter was exposed under the conditions of 60 ° C. and 60% RH at an illuminance of 70,000 lux. The OD value of each color recorded on each printed matter was measured using a thermometer (Spectrolino (registered trademark)) (manufactured by Gretag) at regular intervals from the start of exposure. The measurement conditions were a light source of D50 and a viewing angle of 2 degrees. Further, the measurement was performed for each color using Red for cyan, Green for magenta, and Blue for yellow, and no filter for black. From the results obtained, the following formula:
ROD (%) = (D / D ₀ ) × 100
(In the formula, D represents the OD value after the exposure test, and D ₀ represents the OD value before the exposure test.)
Was used to determine the residual optical density (ROD).

  Further, based on the results of the above test, the light resistance of each color recorded on the recorded matter was ranked A to F using the following criteria.

[Criteria]
Evaluation A: ROD does not decrease to 70% by 70 days.
Evaluation B: ROD decreases to 70% over 50 days and 70 days or less.
Evaluation C: ROD decreases to 70% over 30 days and 50 days or less.
Evaluation D: ROD decreases to 70% over 20 days and 30 days or less.
Evaluation E: ROD decreases to 70% over 10 days and 20 days or less.
Evaluation F: ROD decreases to 70% within 10 days.

  In the present invention, a recorded matter in which a decrease in ROD is small even when exposed to a fluorescent lamp for a long time is excellent. The obtained results are shown in Table 8.

  In addition, from the results of the fluorescent lamp light resistance test for each color, the light resistance of each ink set was ranked using the following criteria.

[Criteria]
Evaluation A: Light resistance test results are all A for three colors (four colors when black is included).
Evaluation B: The light resistance test result is one or more of three colors (four colors when black is included) and B rank ink exists.
Evaluation C: The light resistance test result is one or more of three colors (four colors when black is included) and C rank ink exists.
Evaluation D: The light resistance test result is one or more of three colors (four colors when black is included), and D rank ink exists.
Evaluation E: An E-rank ink exists in one or more of three colors (four colors when black is included) as a result of the light resistance test.
Evaluation F: The light resistance test result is one or more of three colors (four colors when black is included), and F rank ink exists.

  In this evaluation, the evaluation A is the best, and then the evaluation B is excellent. The obtained results are shown in Table 8 as “light resistance (light resistance) of ink set”.

  Furthermore, each recorded matter was evaluated for each ink set using the following criteria for the difference (balance) in ROD change between the colors of the printed matter caused by exposure to a fluorescent lamp.

[Criteria]
Evaluation A: Even after 70 days from the start of the test, the difference between the maximum value and the minimum value in the ROD of each color (hereinafter simply referred to as “ROD difference” in the description of this evaluation method) is less than 15 points.
Evaluation B: Within 50 to 70 days from the start of the test, the ROD difference becomes 15 points.
Evaluation C: Within 30 to 50 days from the start of the test, the ROD difference becomes 15 points.
Evaluation D: The difference in ROD becomes 15 points within 20 to 30 days from the start of the test.
Evaluation E: The ROD difference becomes 15 points within 10 to 20 days from the start of the test.
Evaluation F: The difference in ROD becomes 15 points within 10 days from the start of the test.

  In this evaluation, a small ROD difference is excellent as a recorded matter. Table 8 shows the evaluation results obtained as “light resistance (color balance) of the ink set”.

[Moisture resistance evaluation]
Regarding the ink sets of Examples 1 to 8 and Comparative Examples 1 to 8, characters of Cyan, Magenta, Yellow, and Black (including black only when the ink set includes a black ink composition) and white characters (A solid image of each color with white letters formed on it) is printed on an inkjet-dedicated recording medium <photographic paper (gloss): model number KA420PSK; trade name, manufactured by Seiko Epson Corporation> at the maximum density of each color, It dried for 24 hours in 24 degreeC and 50% RH environment. Subsequently, these were left still in an environment of 40 ° C. and 85% RH where no light was applied. After standing in this environment for 4 days, the degree of bleeding of letters and white letters was visually observed and evaluated based on the following criteria.

[Criteria]
Evaluation A: No oozing of the colorant is observed.
Evaluation B: The bleeding out of the colorant is hardly observed.
Evaluation C: The colorant is slightly exuded and the outline of the character is slightly broken.
Evaluation D: The bleeding of the colorant is observed and the outline of the character is broken.
Evaluation E: Bleeding of the colorant is observed, the character is thick, and the white character is dyed throughout.
Evaluation F: The bleeding out of the colorant is remarkably observed, and the characters and white characters are unreadable.

  The obtained results are shown in Table 9 as “moisture resistance”.

[Evaluation of reflection optical density of each medium of black ink]
For each black ink in the ink sets of Examples 5 to 8, an inkjet-dedicated recording medium <photographic paper (gloss): model number KA420PSK; trade name, manufactured by Seiko Epson Corporation> and <photo mat paper: model number KA420PM; trade name, Seiko Monochrome printing was performed by changing the ink placement weight between Epson Corporation> and plain paper Xerox-4024 (trade name: manufactured by Xerox Corporation). The reflection optical density of the obtained printed matter was measured using a densitometer (Spectrolino (registered trademark)) (manufactured by Gretag). The measurement conditions were a light source of D50, a viewing angle of 2 degrees, and no filter. The maximum value of the obtained reflection optical density was determined. The obtained results are shown in Table 10 as “the maximum value of the reflection optical density in each medium of each black ink”.

  Regarding the evaluation of the three types of five items of ozone resistance, light resistance, and moisture resistance obtained above, the results were re-published in Table 11 and ranked for overall characteristics.

  Regarding comprehensive evaluation, A to F are ranked, evaluation A is the best, and evaluation B is next excellent. The evaluation F is the lowest characteristic.

  INDUSTRIAL APPLICABILITY The present invention has industrial applicability as an ink set, an ink cartridge, an ink jet recording method, and a recorded matter that can record an image having good ozone resistance, light resistance, and moisture resistance on a recording medium. .

Claims (12)

An ink set comprising at least a yellow ink composition, two types of magenta ink compositions having different color densities, and a cyan ink composition,
Each of the two types of magenta ink compositions having different color densities includes , as a colorant, at least one compound represented by the following formula (M-4) and a compound represented by the following formula (M-2). Containing at least one species,

(In the formula (M-4), R _{1 to} R ₁₀ represent a hydrogen atom, an alkyl group, a sulfo group or a salt thereof, and (R ₁ , R ₅ ) and (R ₆ , R ₁₀ ) are each independently , Ru der total 3 or more carbon atoms constituting the both alkyl groups. Further, M represents a hydrogen atom or an alkali metal atom.)

(In the formula (M-2), M represents a hydrogen atom, an ammonium group, or an alkali metal atom, X represents a diaminoalkylene group, and n is 1 or 2.)
Furthermore, the yellow ink composition contains at least one compound represented by the following formula (Y-1) as a colorant,

(In the above formula, X ₁ , X ₂ , Y ₁ , and Y ₂ represent a hydrogen atom or a cyano group, Z ₁ and Z ₂ represent a substituent having an aromatic ring, and R ₁ and R ₂ represent an alkyl group. And M represents a metal atom.)
Further, the cyan ink composition as a cyan dye has the following formula (A):

(In the formula (A), Z1, Z2, Z3 and Z4 are each independently an unsubstituted alkyl group , an unsubstituted cycloalkyl group , an unsubstituted alkenyl group , an unsubstituted aralkyl group , or an unsubstituted aryl group . group, unsubstituted heterocyclic _{group, - (CH 2) 3 SO} 3 M 2 (M 2 is an alkali metal atom) or - (CH ₂₎ represents a _{3 SO 2 NHCH 2 CH (OH} ) CH 3).
An ink set characterized by containing at least one in selected from the compounds represented by either Ranaru group.   2. The ink set according to claim 1, wherein n in the compound represented by the formula (M-2) is 2 in the colorant contained in the magenta ink composition. Of the different two kinds of magenta ink compositions having the color density, the magenta ink composition having a lower color density, relative to the total weight of the magenta ink composition total of the coloring agent has the low color density, the 0.2-1.0 wt% of at least one compound represented by formula (M-4) is contained, and at least one compound represented by formula (M-2) is 0.3- The ink set according to claim 1, which contains 1.5 wt%. Of the different two kinds of magenta ink compositions having the color density, the magenta ink composition having a high color density, relative to the total weight of the magenta ink composition total of the coloring agent has the high color density, the 0.6-2.5 wt% of at least one compound represented by the formula (M-4) is contained, and at least one compound represented by the formula (M-2) is 1.5- The ink set according to claim 1, wherein the ink set is contained by 7.0 wt%.   Of the two types of magenta ink compositions having different color densities, a magenta ink composition having a low color density is represented by the compound represented by the formula (M-4) and the formula (M-2). 5. The ink set according to claim 1, wherein the content ratio of the compound to the compound is 2: 1 to 1: 2 by weight.   Of the two types of magenta ink compositions having different color densities, a magenta ink composition having a high color density is represented by the compound represented by the formula (M-4) and the formula (M-2). The ink set according to any one of claims 1 to 5, wherein the content ratio with respect to the compound is in the range of 1: 1 to 1: 8 by weight. The compound represented by the formula (Y-1) as a colorant contained in the yellow ink composition is a compound represented by the following formula (Y-2). The ink set according to item.

(In the above formula, X ₁ , X ₂ , Y ₁ , and Y ₂ represent a hydrogen atom or a cyano group, and W _{1 to} W ₅ and W _{11 to} W ₁₅ represent a hydrogen atom, a carboxyl group, or a salt thereof, respectively. M represents a metal atom, and t-Bu represents a tertiary butyl group.) The ink set according to claim 1, wherein the yellow ink composition further contains at least one compound represented by the following formula (Y-3) as a colorant.

(In the above formula, R represents a methoxy group or a methyl group, and A represents 1,5-disulfonaft-3-yl or 1,5,7-trisulfonaft-2-yl.) Furthermore ink set according to claim 8, whichever is one wherein with a black ink composition. The ink set according to claim 9, wherein the black ink composition contains a colorant represented by the following formula (Bk-1).

(In the formula (Bk-1), A ₁ is a substituent represented by the following formula (Bk-2) or (Bk-3), and A ₂ is the following formula (Bk-4) or (Bk-5). And A ₃ is a substituent represented by the following formula (Bk-6).)

(In the formula (Bk-2), M represents Li or Na.)

(In the formula (Bk-3), M represents Li or Na.)

(In the formula (Bk-6), M represents Li or Na.) The ink set according to claim 9 or 10, wherein the black ink composition further contains a colorant represented by the following formula (Bk-7).

(In the formula (Bk-7), R ₁ represents a halogen atom, H, SO ₃ M, or COOM, and R ₂ and R ₃ independently represent any of H, SO ₃ M, or COOM. M represents Li or Na, provided that R ₂ and R ₃ are not H.)   The sum of the content of the colorant represented by the formula (Bk-1) and the content of the colorant represented by the formula (Bk-7) is 5 to 8% by weight in the black ink composition. The ink set according to claim 11, wherein