JP2013010824A - Ink set and liquid droplet discharging device using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink set with good dispersibility of pigment contained in the pigment ink even in a case when the pigment ink and dye ink are mixed.SOLUTION: This ink set includes first ink containing water, pigment and a first metal ion as a counter ion of the pigment; and second ink containing water, a dye expressed by general formula (1) and a second metal ion as a counter ion of the dye, where the limiting equivalent conductivity [S cm/eq] of the first metal ion is larger than that of the second metal ion.

Description

  The present invention relates to an ink set and a droplet discharge device using the ink set.

  Conventionally, inks containing pigments or dyes as colorants are known. A pigment ink containing a pigment as a color material is particularly preferably used for recording characters and the like from the viewpoint of less bleeding and good water resistance and light resistance. In addition, a dye ink containing a dye as a coloring material is particularly preferably used for recording an image or the like from the viewpoint that glossiness and color developability are good and the color is clear.

  When pigment ink and dye ink having the above characteristics are used in combination, the recording quality of both characters and images recorded on the recording medium is excellent. For these reasons, ink sets including both pigment inks and dye inks have been widely used in recent years.

  By the way, when an ink set including a pigment ink and a dye ink is applied to an ink jet recording apparatus, the pigment ink and the dye ink may be mixed on a nozzle surface having a nozzle hole for ejecting ink. In such a case, the dispersibility of the pigment in the pigment ink may be destroyed by the dye ink, and the pigment may aggregate. In particular, when the nozzle surface is cleaned by a wipe member provided for cleaning the nozzle surface, the nozzle holes are blocked by the aggregates of the pigment, and the ejection stability of the ink may be lowered. . In addition, there is a problem that the aggregate of the pigment adhering to the nozzle surface falls on the recording medium.

  In order to reduce such agglomeration of the pigment, Patent Document 1 describes that a polymer having a lactam structure is added to the dye ink. Patent Document 2 describes that the amount of counter ions (counter ions) contained in pigment ink and dye ink is specified.

JP 2010-84136 A JP 2006-2094 A

  However, in the above-described prior art, when the pigment ink and the dye ink are mixed, the dispersion and destruction of the pigment cannot be sufficiently suppressed, and the aggregation of the pigment may occur. In particular, when a dye ink containing a specific dye improved to improve characteristics such as weather resistance (for example, light resistance and gas resistance) is used, the dye ink and the pigment ink are mixed. In some cases, the dispersibility of the pigment was significantly reduced.

  One of the objects according to some embodiments of the present invention is to provide an ink set in which the dispersibility of the pigment contained in the pigment ink is good even when the pigment ink and the dye ink are mixed. .

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the ink set according to the present invention is:
Water, a pigment and a first ink containing a first metal ion as a counter ion of the pigment;
Water, a dye represented by the following general formula (1), and a second ink containing a second metal ion as a counter ion of the dye;
Have
The ultimate equivalent conductivity [S · cm ² / eq] of the first metal ion described in (Condition 1) or (Condition 2) below is the second metal described in (Condition 3) or (Condition 4) below. It is larger than the ultimate equivalent conductivity [S · cm ² / eq] of ions.
(Condition 1) When the first metal ion is composed of a single metal ion, the ultimate equivalent conductivity of the first metal ion is the ultimate equivalent conductivity of the single metal ion (Condition 2) the first When the metal ions are composed of two or more kinds of metal ions, the ultimate equivalent conductivity of the first metal ions is the average ultimate equivalent conductivity of the two or more kinds of metal ions (Condition 3). When the ion is composed of a single metal ion, the ultimate equivalent conductivity of the second metal ion is the ultimate equivalent conductivity of the single metal ion (Condition 4). The second metal ion is a metal of two or more types. When it consists of ions, the ultimate equivalent conductivity of the second metal ion is the average ultimate equivalent conductivity of the two or more metal ions.

（式（１）中、
破線で表される環Ａ乃至Ｄは、それぞれ独立にポルフィラジン環に縮環したベンゼン環又は６員環の含窒素複素芳香環を表し、含窒素複素芳香環の個数は平均値で０．００を超えて３．００以下であり、残りはベンゼン環であり、
ＥはＣ２−Ｃ１２アルキレンを表し、
Ｘは、置換基として、スルホ基、カルボキシ基、リン酸基、スルファモイル基、カルバモイル基、ヒドロキシ基、Ｃ１−Ｃ６アルコキシ基、アミノ基、モノＣ１−Ｃ４アルキルアミノ基、ジＣ１−Ｃ４アルキルアミノ基、モノＣ６−Ｃ１０アリールアミノ基、ジＣ６−Ｃ１０アリールアミノ基、Ｃ１−Ｃ３アルキルカルボニルアミノ基、ウレイド基、Ｃ１−Ｃ６アルキル基、ニトロ基、シアノ基、ハロゲン原子、Ｃ１−Ｃ６アルキルスルホニル基、及びＣ１−Ｃ６アルキルチオ基よりなる群から選択される１種類又は２種類以上の置換基を有しても良い、スルホアニリノ基、カルボキシアニリノ基、ホスホノアニリノ基、スルホナフチルアミノ基、カルボキシナフチルアミノ基又はホスホノナフチルアミノ基であり、
Ｒは水素原子；スルホ基；カルボキシ基；リン酸基；スルファモイル基；カルバモイル基；ヒドロキシ基；Ｃ１−Ｃ６アルコキシ基；アミノ基；モノＣ１−Ｃ６アルキルアミノ基；ジＣ１−Ｃ６アルキルアミノ基；モノアリールアミノ基；ジアリールアミノ基；Ｃ１−Ｃ３アルキルカルボニルアミノ基；ウレイド基；Ｃ１−Ｃ６アルキル基；ニトロ基；シアノ基；ハロゲン原子；Ｃ１−Ｃ６アルキルスルホニル基；又はアルキルチオ基；を表し、
基Ｆはフェニル基；又は、６員含窒素複素芳香環基；を表し、
ａは１以上６以下の整数を表し、
ｂは平均値で０．００以上３．９０未満であり、
ｃは平均値で０．１０以上４．００未満であり、
且つｂ及びｃの和は、平均値で１．００以上４．００未満である。）
適用例１のインクセットによれば、第１インクおよび第２インクが混合された場合であっても、第１インクに含まれる顔料の分散性が良好である。

(In the formula (1),
Rings A to D represented by broken lines each independently represent a benzene ring or a 6-membered nitrogen-containing heteroaromatic ring condensed to a porphyrazine ring, and the average number of nitrogen-containing heteroaromatic rings is 0.00. Exceeding 3.00 and the remainder is a benzene ring,
E represents C2-C12 alkylene;
X is a sulfo group, carboxy group, phosphate group, sulfamoyl group, carbamoyl group, hydroxy group, C1-C6 alkoxy group, amino group, mono C1-C4 alkylamino group, di-C1-C4 alkylamino group as a substituent. Mono-C6-C10 arylamino group, di-C6-C10 arylamino group, C1-C3 alkylcarbonylamino group, ureido group, C1-C6 alkyl group, nitro group, cyano group, halogen atom, C1-C6 alkylsulfonyl group, And a sulfoanilino group, a carboxyanilino group, a phosphonoanilino group, a sulfonaphthylamino group, a carboxynaphthylamino group, or one or more kinds of substituents selected from the group consisting of C1-C6 alkylthio groups, A phosphononaphthylamino group,
R represents a hydrogen atom; a sulfo group; a carboxy group; a phosphate group; a sulfamoyl group; a carbamoyl group; a hydroxy group; a C1-C6 alkoxy group; an amino group; a mono C1-C6 alkylamino group; Diarylamino group; C1-C3 alkylcarbonylamino group; ureido group; C1-C6 alkyl group; nitro group; cyano group; halogen atom; C1-C6 alkylsulfonyl group; or alkylthio group;
Group F represents a phenyl group; or a 6-membered nitrogen-containing heteroaromatic group;
a represents an integer of 1 to 6,
b is an average value of 0.00 or more and less than 3.90,
c is an average value of 0.10 or more and less than 4.00,
The sum of b and c is an average value of 1.00 or more and less than 4.00. )
According to the ink set of Application Example 1, the dispersibility of the pigment contained in the first ink is good even when the first ink and the second ink are mixed.

[Application Example 2]
In application example 1,
The first metal ion may be at least one of sodium ion and lithium ion.

[Application Example 3]
In application example 1 or application example 2,
The second metal ion may be at least one of potassium ion and sodium ion.

[Application Example 4]
In any one of Application Examples 1 to 3,
In the general formula (1),
The nitrogen-containing heteroaromatic rings in rings A to D are each independently a pyridine ring fused at the 2-position and the 3-position, or the 3-position and the 4-position; or a pyrazine ring fused at the 2-position and the 3-position ,
E is a linear C2-C4 alkylene,
X is a substituent such as sulfo group, carboxy group, hydroxy group, C1-C6 alkoxy group, amino group, mono C1-C4 alkylamino group, di-C1-C4 alkylamino group, C1-C3 alkylcarbonylamino group, nitro A sulfoanilino group which may have 0 or 2 substituents of one or two types selected from the group consisting of a group, a halogen atom, a C1-C6 alkylsulfonyl group, and a C1-C6 alkylthio group; A carboxyanilino group optionally having 0 to 2 substituents of one or two types selected from the group consisting of a sulfo group, a carboxy group, a hydroxy group, and a sulfamoyl group; a phosphonoanilino group; The group may have 0 to 2 substituents of one or two types selected from a sulfo group and a hydroxy group. Sulfo naphthyl amino group; a and,
R is a hydrogen atom; a sulfo group; a carboxy group; a C1-C6 alkoxy group; a C1-C6 alkyl group; or a halogen atom;
A group F is a phenyl group; or a pyridyl group in which R is a hydrogen atom;
a can be an integer of 1 or 2.

[Application Example 5]
In any one of Application Examples 1 to 4,
In the general formula (1),
The nitrogen-containing heteroaromatic rings in rings A to D are each independently a pyridine ring condensed at the 2-position and 3-position;
E is ethylene,
X is a sulfoanilino group optionally having 0 or 1 sulfo group as a substituent; or a sulfonaphthylamino group having 2 sulfo groups as a substituent,
R is a hydrogen atom, a sulfo group, or a carboxy group,
The group F is a phenyl group, or a pyridyl group in which R is a hydrogen atom,
a is an integer of 1;
b is an average value of 0.00 or more and less than 3.90,
c is an average value of 0.10 or more and less than 4.00,
The sum of b and c can be an average value of 1.00 or more and less than 4.00.

[Application Example 6]
One aspect of the droplet discharge device according to the present invention is:
An ink set comprising the first ink and the second ink according to any one of Application Examples 1 to 5,
A nozzle surface having nozzle holes for discharging the first ink and the second ink;
A wipe member for wiping the nozzle surface;
Have

1 is a perspective view illustrating a configuration of a printer according to an embodiment of the present invention. Schematic which shows the arrangement | sequence of the nozzle provided in the inkjet head in embodiment of this invention. FIG. 2 is a partial cross-sectional view showing an internal configuration of the ink jet head in the embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described. The embodiment described below describes an example of the present invention. In addition, the present invention is not limited to the following embodiments, and includes various modifications that are implemented within a range that does not change the gist of the present invention.

  In the present invention, acidic functional groups such as a sulfo group and a carboxy group are represented in the form of a free acid unless otherwise specified.

  In the present invention, “Cv-Cw alkyl (group)” (v and w are each an integer) means an alkyl group containing v to w carbon atoms. For example, C1-C4 alkyl refers to an alkyl group containing 1-4 carbon atoms. The alkyl group may have a linear or branched structure unless otherwise specified.

  Further, “Cv-Cw alkoxy (group)”, “Cv-Cw alkylamino (group)”, “Cv-Cw arylamino (group)”, “Cv-Cw alkylcarbonylamino (group)”, “Cv-Cw” “Alkylsulfonyl (group)” and “Cv-Cw alkylthio (group)”, similarly to “Cv-Cw alkyl (group)”, represent a group containing v to w carbon atoms, unless otherwise specified, Either a linear or branched structure may be used.

1. Ink Set According to an embodiment of the present invention, an ink set includes water, a pigment, a first ink containing a first metal ion as a counter ion of the pigment, water, a dye represented by the following general formula (1), and A second ink containing a second metal ion as a counter ion of the dye, and the equivalent equivalent conductivity [S · cm ^{2 of} the first metal ion described in (Condition 1) or (Condition 2) below: / Eq] is larger than the ultimate equivalent conductivity [S · cm ² / eq] of the second metal ion described in (Condition 3) or (Condition 4) below.
(Condition 1) When the first metal ion is composed of a single metal ion, the ultimate equivalent conductivity of the first metal ion is the ultimate equivalent conductivity of the single metal ion (Condition 2) the first When the metal ions are composed of two or more kinds of metal ions, the ultimate equivalent conductivity of the first metal ions is the average ultimate equivalent conductivity of the two or more kinds of metal ions (Condition 3). When the ion is composed of a single metal ion, the ultimate equivalent conductivity of the second metal ion is the ultimate equivalent conductivity of the single metal ion (Condition 4). The second metal ion is a metal of two or more types. In the case of consisting of ions, the ultimate equivalent conductivity of the second metal ion is the average ultimate equivalent conductivity of the two or more metal ions. The ultimate equivalent conductivity of the first metal ion is that of the second metal ion. More than the ultimate equivalent conductivity If it is larger, the dispersibility of the pigment contained in the first ink is less likely to deteriorate when the first ink and the second ink are mixed. Thereby, even when the ink set according to the present embodiment is used in a droplet discharge device to be described later, it is possible to reduce the occurrence of discharge failure due to nozzle clogging or the like. On the other hand, when the ultimate equivalent conductivity of the first metal ions is equal to or less than the ultimate equivalent conductivity of the second metal ions, the dispersion of the pigment contained in the first ink when the first ink and the second ink are mixed. In some cases, the properties of the pigments deteriorate and pigment aggregation occurs.

The ultimate equivalent conductivity (S · cm ² / eq) of a metal ion is an eigenvalue in an infinite dilution state and is known as a value defined by the law of ion independent movement. That is, in the law of independent ion transfer, the limiting molar conductivity of the electrolyte in an infinite dilution state is expressed as the sum of the limiting molar conductivity of cations and anions. The infinite dilution state does not mean that there is no electrolyte (ion), but the cation-anion distance in the solution is infinite, and the cation and the anion affect each other. It means not. In addition, the equivalent conductivity (S · cm ² / eq) of a metal ion refers to a value obtained by dividing the ultimate molar conductivity (S · cm ² / mol) of the metal ion by the valence of the metal ion.

The ultimate equivalent conductivity of metal ions is often known. Specifically, the ultimate equivalent conductivity (S · cm ² / eq) at 25 ° C. is 73.5 potassium ions (K ⁺ ), sodium ions It is 50.1 for (Na ⁺ ) and 38.7 for lithium ion (Li ⁺ ) (Electrochemical Handbook, Electrochemical Handbook 4th Edition). The ultimate equivalent conductivity of metal ions can also be determined experimentally, and determined by measuring the change in equivalent conductivity concentration and extrapolating to zero concentration using an appropriate method. Can do.

  Further, when the first metal ion is composed of two or more kinds of metal ions, the ultimate equivalent conductivity of the first metal ion is set as an average ultimate equivalent conductivity. The average ultimate equivalent conductivity is an average value of the ultimate equivalent conductivity of metal ions contained in the ink as a counter ion of the pigment. For example, the average ultimate equivalent conductivity of m X ions and n Y ions is [(the ultimate equivalent conductivity of X ions) × m + (the ultimate equivalent conductivity of Y ions) × n] / (M + n). In addition, also when a 2nd metal ion consists of 2 or more types of metal ions, an average ultimate equivalent conductivity can be calculated | required similarly to a 1st metal ion.

  The reason why the relationship between the ultimate equivalent conductivity affects the aggregation of the pigment has not been clarified in detail, but is considered to be due to the following mechanism.

  For example, when the ultimate equivalent conductivity of the second metal ion is larger than the ultimate equivalent conductivity of the first metal ion, when the first ink and the second ink are mixed, the conductivity around the pigment particles is increased. Get higher. That is, the pigment particles are likely to encounter metal ions having a high ultimate equivalent conductivity. As a result, it is considered that the electric double layer around the pigment contracts, thereby reducing the interparticle distance between the pigment particles and causing aggregation of the pigment.

  On the other hand, when the ultimate equivalent conductivity of the second metal ions is smaller than the ultimate equivalent conductivity of the first metal ions, the conductivity around the pigment particles is unlikely to increase. For this reason, it is considered that the aggregation of the pigment is less likely to occur.

  The first ink includes a pigment and a metal salt of a first metal ion. Thereby, the dispersibility of the pigment is improved and the aggregation of the pigment is less likely to occur.

  The second ink includes a dye represented by the general formula (1) and a metal salt of a second metal ion. This improves the solubility of the dye.

1.1. First Ink The ink set according to the present embodiment has a first ink. Hereinafter, the components contained in the first ink will be described in detail.

1.1.1. Pigment The first ink contains a pigment. Known pigments can be used as the pigment, but self-dispersing pigments are preferred. Self-dispersing pigments are pigments that can be dispersed in an aqueous medium without a dispersant. Here, “dispersed in an aqueous medium without a dispersant” means a state in which the surface is stably present in an aqueous medium by a hydrophilic group on the surface without using a dispersant for dispersing the pigment. Say. When a self-dispersing pigment is used, the amount of dispersant used to disperse the pigment can be reduced, so that foaming of the ink due to the dispersant can be reduced, and an ink with good ejection stability can be easily prepared.

Self-dispersing pigments can have hydrophilic groups on the pigment surface. Hydrophilic group of the surface of the _{pigment, -OM, -COOM, -CO -,} - SO 3 M, -SO 2 M, -SO 2 NH 2, -RSO 2 M, -PO 3 HM, -PO 3 M 2, - SO ₂ NHCOR, —NH ₃ , and —NR ₃ (wherein M is a hydrogen atom, an alkali metal (eg, lithium, sodium, potassium), ammonium, an optionally substituted phenyl group, or organic It represents ammonium, and R is preferably one or more hydrophilic groups selected from the group consisting of an alkyl group having 1 to 12 carbon atoms or a naphthyl group which may have a substituent.

  The first ink according to the present embodiment preferably includes a pigment and a metal salt of a first metal ion, and the pigment included in the first ink substantially includes a metal salt of the first metal ion. As described above, when the pigment contained in the first ink has a metal salt structure, the dispersibility of the pigment is improved and aggregation of the pigment is less likely to occur.

  The first metal ion contained in the first ink as the counter ion of the pigment is preferably at least one of potassium ion and sodium ion. Thereby, the dispersibility of the pigment in the first ink can be improved.

  The pigment is produced, for example, by bonding (grafting) the hydrophilic group to the surface of the pigment by performing physical treatment or chemical treatment. Examples of the physical treatment include vacuum plasma treatment. Examples of the chemical treatment include a wet oxidation method of oxidizing with an oxidizing agent in water, a method of binding a carboxyl group via a phenyl group by binding p-aminobenzoic acid to the pigment surface, and the like.

  When the first ink is used as a black ink (hereinafter also referred to as “pigment black ink”), the pigment is oxidized with hypohalous acid and / or hypohalite, oxidized with ozone, Or it is preferable that it is surface-treated by oxidation treatment with persulfuric acid and / or persulfate in terms of high color development.

  When the first ink is used as an ink of a color other than black (hereinafter also referred to as “pigment color ink”), the pigment may have the above hydrophilic group via a phenyl group on the surface thereof. From the viewpoint of high color development. As the surface treatment means for bonding a hydrophilic group to the pigment surface via a phenyl group, various known surface treatment means can be applied, and sulfanilic acid, p-aminobenzoic acid, 4-aminosalicylic acid and the like can be applied to the pigment surface. Examples thereof include a method of bonding a hydrophilic group via a phenyl group.

  As the pigment used in the pigment black ink, for example, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used. Preferred specific examples of carbon black include No. 2300, 900, MCF88, no. 20B, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, No2200B (manufactured by Mitsubishi Chemical Corporation), color black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 30, U, V, 140U, special black 6, 5, 4A, 4, 250 (above Evonik Degussa), Conductex SC, Raven 1255, 5750, 5250, 5000, 3500, 1255, 700 (above Colombia Carbon), Regal 400R, 330R, 660R, Mogul L , Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, Elftex 12 (manufactured by Cabot Corporation), and the like. These carbon blacks may be used alone or as a mixture of two or more.

  In addition, pigments used for pigment color inks include pigment red, pigment violet, pigment blue and the like described in the color index, as well as phthalocyanine, azo, anthraquinone, azomethine, condensed ring systems, etc. A pigment can be illustrated. In addition, organic pigments such as orange No. 228, 405, blue No. 1 and 404, and inorganic pigments such as titanium oxide, zinc oxide, zirconium oxide, iron oxide, ultramarine blue, bitumen, and chromium oxide can be mentioned. For example, C.I. I. Pigment red 1,3,5,8,9,16,17,19,22,38,57: 1,90,112,122,123,127,146,184, C.I. I. Pigment Bio Red 1,3,5: 1, 16, 19, 23, 38, C.I. I. And CI pigment blue 1, 2, 15, 15: 1, 15: 2, 15: 3, 15: 4, and 16.

  Moreover, it is also possible to use a commercial item as a pigment, for example, microjet CW1 (made by Orient Chemical Industry Co., Ltd.), CAB-O-JET250C, CAB-O-JET260M (above made by Cabot Corporation), and the like. .

  The content of the pigment is preferably 1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 10% by mass or less, with respect to the total mass of the first ink composition.

  The pigment preferably has an average particle size in the range of 50 to 250 nm from the viewpoint of storage stability of the ink and prevention of nozzle clogging.

1.1.2. Water The ink composition according to the present embodiment contains water. Water functions as a main solvent for dispersing or dissolving the above-described pigment.

  The water is preferably water from which ionic impurities such as pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water or ultrapure water are removed as much as possible. Further, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, it is preferable because the generation of mold and bacteria can be prevented when the pigment dispersion and the ink using the same are stored for a long period of time.

  The water contained in the first ink according to the present embodiment is preferably 50% by mass or more with respect to the total mass of the first ink.

1.1.3. Other Components The first ink according to the present embodiment can contain a surfactant. Examples of the surfactant include nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants. Surfactant may be used individually by 1 type, and may be used in mixture of 2 or more types.

  Among these, nonionic surfactants can improve the permeability and fixability of the ink to the recording medium, and the shape of the ink droplets deposited on the recording medium by the ink jet recording method is close to a perfect circle. Since it can be used, it can be preferably used.

  Among nonionic surfactants, acetylene glycol surfactants are more preferably used because they are excellent in ability to maintain surface tension and interfacial tension appropriately and have almost no foaming property. be able to. Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, and 3,5. -Dimethyl-1-hexyne-3ol, 2,4-dimethyl-5-hexyn-3-ol and the like. Also, commercially available acetylene glycol surfactants can be used. For example, Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA (all are trade names, manufactured by Air Products and Chemicals, Inc.), Olfin B, Y, P, A, STG SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP. 4001, EXP. 4036, EXP. 4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), acetylenol E00, E00P, E40, E100 (all trade names, Kawaken Fine Chemical Co., Ltd.).

  When the surfactant is contained, the content thereof is preferably 0.1% by mass or more and 5% by mass or less with respect to the total mass of the first ink.

  The first ink according to the present embodiment can contain a penetration enhancer. The penetration enhancer has an action of further improving the wettability of the ink with respect to the recording medium and applying it uniformly. As a result, it is possible to further reduce the density unevenness and bleeding of the ink of the formed image, and to further improve the color density of the image. A penetration enhancer may be used individually by 1 type, and may be used in mixture of 2 or more types.

  Examples of the penetration enhancer include glycol ethers. Glycol ethers are particularly excellent in effect as penetration enhancers. Examples of glycol ethers include ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol. And monobutyl ether. Among these, triethylene glycol monobutyl ether can be preferably used from the viewpoint of excellent compatibility with the components contained in the first ink according to the present embodiment.

  When the penetration accelerator is contained, the content thereof is preferably 1% by mass or more and 15% by mass or less with respect to the total mass of the first ink.

  The first ink according to the present embodiment can contain a humectant. Examples of the humectant include 1,2-alkanediols, polyhydric alcohols, pyrrolidone derivatives, ureas, and the like. A moisturizer may be used individually by 1 type, and may be used in mixture of 2 or more types.

  Since 1,2-alkanediols are excellent in the action of increasing the wettability of the ink to the recording medium and uniformly wetting it, an excellent image can be formed on the recording medium. Examples of 1,2-alkanediols include 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, and the like. . When 1,2-alkanediols are contained, the content thereof is preferably 1% by mass or more and 20% by mass or less with respect to the total mass of the first ink.

  Polyhydric alcohols can be preferably used from the viewpoint that when the first ink is used in an ink jet recording apparatus, clogging or ejection failure can be reduced by suppressing drying and solidification of the ink on the nozzle surface of the head. . Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, Examples include glycerin. When polyhydric alcohols are contained, the content thereof is preferably 1% by mass or more and 30% by mass or less with respect to the total mass of the first ink.

  The pyrrolidone derivative can be preferably used from the viewpoint of suppressing clogging and ejection failure by suppressing drying and solidification of the ink on the nozzle surface of the head. Examples of pyrrolidone derivatives include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone, N-butyl-2-pyrrolidone, and 5-methyl-2-pyrrolidone. Etc. When the pyrrolidone derivative is contained, the content thereof is preferably 1% by mass or more and 10% by mass or less with respect to the total mass of the first ink.

  Ureas can be preferably used from the viewpoint that when the first ink is used in an ink jet recording apparatus, clogging or ejection failure can be reduced by suppressing drying and solidification of the ink on the nozzle surface of the head. Examples of ureas include urea, thiourea, ethylene urea, 1,3-dimethylimidazolidinone and the like. When urea is contained, the content thereof is preferably 1% by mass or more and 20% by mass or less with respect to the total mass of the first ink.

  The 1st ink which concerns on this embodiment can contain a pH adjuster. The pH adjuster can easily adjust the pH value of the first ink. A pH adjuster may be used individually by 1 type, and may be used in mixture of 2 or more types.

  Examples of pH adjusters include inorganic acids (for example, sulfuric acid, hydrochloric acid, nitric acid), inorganic bases (for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia), organic bases (triethanolamine, diethanolamine, mono Ethanolamine, tri-iso-propanolamine), organic acids (for example, adipic acid, citric acid, succinic acid, etc.) and the like.

  Among the above, it is preferable to use at least one of an organic acid and an organic base as the pH adjuster. In particular, when an organic acid and an organic base are used in combination, the pH buffering ability is higher than that of a combination of an inorganic acid and an inorganic base, an inorganic acid and an organic base, or an organic acid and an inorganic base. Therefore, when an organic acid and an organic base are used in combination, the effect of suppressing fluctuations in pH value is further improved, and the effect of being easily set to a desired pH is achieved.

  The 1st ink which concerns on this embodiment can contain antiseptic | preservative and antifungal agent, a rust preventive agent, a chelating agent, etc. further. If the first ink according to the present embodiment contains these compounds, the characteristics may be further improved.

  Examples of antiseptics and fungicides include sodium benzoate, sodium pentachlorophenol, 2-pyridinethiol-1-oxide sodium, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazoline-3-one Etc. Examples of commercially available products include Proxel XL2, Proxel GXL (above trade name, manufactured by Avicia), Denside CSA, NS-500W (above trade name, manufactured by Nagase ChemteX Corporation), and the like.

  Examples of the rust inhibitor include benzotriazole.

  Examples of the chelating agent include ethylenediaminetetraacetic acid and salts thereof (such as ethylenediaminetetraacetic acid dihydrogen disodium salt).

1.2. Second Ink The ink set according to the present embodiment has a second ink. In the second ink, components other than the pigment among the components contained in the first ink described above can be used in the same manner, and thus the description of the components used in the same manner is omitted.

1.2.1. Dye (a) Dye The second ink according to this embodiment comprises a dye represented by the following general formula (1) (hereinafter also referred to as “first dye”) and a second metal ion as a counter ion of the dye. contains. The first dye is a porphyrazine compound. That is, tetrabenzoporphyrazine (usually referred to as phthalocyanine) is replaced with nitrogen-containing heteroaromatic rings in excess of four benzo (benzene) rings and not more than three.

  The first dye has the property of not easily decomposing even when irradiated with light or exposed to atmospheric gas (especially ozone). Therefore, an image formed using the second ink is excellent in light resistance and gas resistance (particularly ozone resistance), and hardly undergoes discoloration or fading due to the influence of light or air. Further, the first dye has a property that it is difficult to decompose in the ink. Therefore, the second ink is excellent in storage stability.

  It is known that when an ink containing a metal phthalocyanine dye having improved performance such as gas resistance is used for high duty printing, a red floating phenomenon (so-called bronzing phenomenon) occurs in a recorded image. However, the first dye is preferably used because it has an excellent property that an image recorded when used in an ink is less likely to cause a bronze phenomenon despite being excellent in gas resistance. it can.

  The content of the first dye is preferably 1% by mass to 15% by mass and more preferably 1% by mass to 10% by mass with respect to the total mass of the second ink. When the content of the first dye is within the above range, the color density of the recorded image can be improved, and the light resistance and gas resistance can be improved.

  In the formula (1), examples of the nitrogen-containing heteroaromatic ring in the rings A to D (four rings A, B, C, and D) represented by broken lines include, for example, a pyridine ring, a pyrazine ring, a pyrimidine ring, and Examples thereof include nitrogen-containing heteroaromatic rings containing 1 or 2 nitrogen atoms such as pyridazine rings. Among these, a pyridine ring or a pyrazine ring is preferable, and a pyridine ring is more preferable. As the number of nitrogen-containing heteroaromatic rings increases, the ozone resistance improves, but bronzing tends to occur easily. The number of nitrogen-containing heterocyclic rings is appropriately determined in consideration of ozone resistance and bronze resistance. Adjust and select a well-balanced ratio. Although the number of nitrogen-containing heteroaromatic rings depends on the type of heterocycle, it cannot be generally stated, but is usually an average value of more than 0.00 to 3.00 or less, preferably 0.20 to 2.00, More preferably, it is 0.50 or more and 1.75 or less, More preferably, it is the range of 0.75 or more and 1.50 or less. The remaining rings A to D are benzene rings, and the benzene rings in the rings A to D are also generally average values of 1.00 or more and less than 4.00, preferably 2.00 or more and 3.80 or less. Preferably they are 2.25 or more and 3.50 or less, More preferably, they are 2.50 or more and 3.25 or less. The porphyrazine compound of the present invention is a mixture of a plurality of compounds, as is apparent from the fact that the number of nitrogen-containing heteroaromatic rings of rings A to D is represented by an average value.

  In the present specification, unless otherwise specified, the number of the nitrogen-containing heteroaromatic rings is rounded off to the second digit by rounding off the third digit after the decimal point. However, for example, when the number of nitrogen-containing heteroaromatic rings is 1.375 and the number of benzene rings is 2.625, when both are rounded off, the former becomes 1.38 and the latter becomes 2.63, and the total of the two is ring A to A The total of D exceeds 4.00. In such a case, for the sake of convenience, the third decimal place on the nitrogen-containing heteroaromatic ring side is rounded down, and only the benzene ring side is rounded off, so that the former is described as 1.37 and the latter as 2.63. As for b and c in formula (1), as described below, in principle, the third digit after the decimal point is rounded to the second digit, but in the same case, three digits after the decimal point on the b side. Cut off the eyes and round off only the c side.

  In said formula (1), as alkylene in E, a linear, branched or cyclic alkylene is mentioned, A linear or cyclic is preferable and a linear is more preferable. The range of carbon number is usually C2-C12, preferably C2-C6, more preferably C2-C4, and still more preferably C2-C3. Specific examples of E include ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, and the like; branched chains such as 2-methylethylene; cyclopropylenediyl , 1,2- or 1,3-cyclopentylenediyl, cyclic cyclohexylenediyl such as 1,2-, 1,3- or 1,4-; Preferred is ethylene, propylene, butylene, pentylene, or hexylene, more preferred is ethylene, propylene, or butylene, still more preferred is ethylene or propylene, and particularly preferred is ethylene.

In the formula (1), X represents a sulfoanilino group, a carboxyanilino group, a phosphonoanilino group, a sulfonaphthylamino group, a carboxynaphthylamino group, or a phosphononaphthylamino group. The number of substitutions of sulfo, carboxy and phosphono in these anilino group and naphthylamino group are all one. Specific examples of X include a sulfoanilino group such as 2-sulfoanilino, 3-sulfoanilino and 4-sulfoanilino; a carboxyanilino group such as 2-carboxyanilino, 3-carboxyanilino and 4-carboxyanilino; 2-phosphonoanilino, 3 -Phosphonoanilino groups such as phosphonoanilino, 4-phosphonoanilino; 3-sulfo-1-naphthylamino, 6-sulfo-1-naphthylamino, 8-sulfo-1-naphthylamino, 1-sulfo-2-naphthylamino, 3-sulfo- 2-naphthylamino, 4-sulfo-2-naphthylamino, 5-sulfo-2-naphthylamino, 6-sulfo-2-naphthylamino, 7-sulfo-2-naphthylamino, 8-sulfo-2-naphthylamino, etc. A sulfonaphthylamino group; and the like. “Phosphono” means a phosphate group [—P (O) (OH) ₂ ]. Among these, as X, a sulfoanilino group, a carboxyanilino group, a phosphonoanilino group, or a sulfonaphthylamino group is preferable, and a sulfoanilino group is particularly preferable.

  The sulfoanilino group, carboxyanilino group, phosphonoanilino group, sulfonaphthylamino group, carboxynaphthylamino group or phosphononaphthylamino group in X is, as a substituent, a sulfo group; a carboxy group; a phosphate group; a sulfamoyl group; a carbamoyl group. Hydroxy group; C1-C6 alkoxy group; amino group; mono C1-C4 alkylamino group; diC1-C4 alkylamino group; monoarylamino group; diarylamino group; C1-C3 alkylcarbonylamino group; -C6 alkyl group; nitro group; cyano group; halogen atom; C1-C6 alkylsulfonyl group; and C1-C6 alkylthio group; and one or more groups selected from the group consisting of further. The group of 20 groups from the sulfo group to the C1-C6 alkylthio group mentioned here is hereinafter simply referred to as “group of 20 substituent groups”. The number of substitutions in X of the group selected from the group of 20 substituents is usually 0 to 4, preferably 0 to 3, more preferably 0 to 2, and even more preferably 0 or 1. . The substitution position of the group selected from the group of 20 substituents is not particularly limited, but the carbon atom in the anilino group and naphthylamino group, that is, on the benzene ring in the former case, on the naphthalene ring in the latter case. Is preferably substituted.

  Examples of the C1-C6 alkoxy group in the group of 20 substituents include straight-chain, branched-chain, and cyclic groups, preferably straight-chain or branched-chain groups, and more preferably straight-chain groups. The range of carbon number is usually C1-C6, preferably C1-C4, more preferably C1-C3. Specific examples include straight chain such as methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexyloxy; isopropoxy, isobutoxy, sec-butoxy, t-butoxy, isopentyloxy, isohexyl Branched chain such as xyloxy; cyclic such as cyclopropoxy, cyclopentoxy, cyclohexyloxy; and the like. Of these, methoxy or ethoxy is preferable, and methoxy is particularly preferable.

  Examples of the mono C1-C4 alkylamino group in the group of 20 substituents include straight-chain or branched-chain groups, and the range of the carbon number is usually C1-C4, preferably C1-C3. Specific examples include straight chain such as methylamino, ethylamino, n-propylamino, and n-butylamino; branched chain such as isopropylamino, isobutylamino, sec-butylamino, and t-butylamino; It is done. Of these, methylamino is preferred.

  Examples of the di-C1-C4 alkylamino group in the group of 20 substituents include dialkylamino groups independently having two alkyl moieties mentioned for the monoalkylamino group. Specific examples include dimethylamino, diethylamino, methylethylamino and the like. Of these, dimethylamino is preferred.

  The monoarylamino group in the group of 20 substituents includes a mono C6-C10 aromatic amino group, preferably a phenylamino group or a naphthylamino group, more preferably a phenylamino group.

  Examples of the diarylamino group in the group of 20 substituents include diarylamino groups independently having two aryls mentioned for the monoarylamino group. Preferred are those having the same aryl, more preferably two phenyls, and specific examples include diphenylamino.

  Examples of the C1-C3 alkylcarbonylamino group in the group of 20 substituents include linear or branched ones, and linear ones are preferred. Specific examples thereof include linear ones such as methylcarbonylamino (acetylamino), ethylcarbonylamino, and n-propylcarbonylamino; branched ones such as isopropylcarbonylamino. Of these, acetylamino is preferred.

  The C1-C6 alkyl group in the group of 20 substituents includes linear, branched or cyclic C1-C6, preferably C1-C4, more preferably C1-C3 alkyl groups. Among these, linear or branched ones are preferable, and linear ones are more preferable. Specific examples include straight chain such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl; isopropyl, isobutyl, sec-butyl, t-butyl, isopentyl, isohexyl, etc. Examples include branched ones; cyclic ones such as cyclopropyl, cyclopentyl and cyclohexyl; and the like. Of these, methyl is preferred.

  The halogen atom in the group of 20 substituents includes a fluorine atom, a chlorine atom and a bromine atom, preferably a fluorine atom or a chlorine atom, and more preferably a chlorine atom.

  The C1-C6 alkylsulfonyl group in the group of 20 substituents includes a linear or branched C1-C6, preferably C1-C4, more preferably a C1-C3 alkylsulfonyl group. Those are preferred. Specific examples include linear chains such as methanesulfonyl (methylsulfonyl), ethanesulfonyl (ethylsulfonyl), n-propanesulfonyl (n-propylsulfonyl), n-butylsulfonyl, n-pentylsulfonyl, and n-hexylsulfonyl. A branched chain such as isopropylsulfonyl and isobutylsulfonyl; and the like. Of these, methylsulfonyl is preferred.

  Examples of the C1-C6 alkylthio group in the group of 20 substituents include linear or branched C1-C6, preferably C1-C4, more preferably C1-C3 alkylthio groups. preferable. Specific examples include straight chain such as methylthio, ethylthio, n-propylthio, n-butylthio, n-pentylthio, n-hexylthio; isopropylthio, isobutylthio, t-butylthio, isopentylthio, isohexylthio, etc. Or a branched chain of Of these, methylthio is preferred.

  When X is a sulfoanilino group, among the group of 20 substituents, sulfo group, carboxy group, hydroxy group, C1-C6 alkoxy group, amino group, mono C1-C4 alkylamino group, di-C1-C4 alkylamino group Group, C1-C3 alkylcarbonylamino group, C1-C6 alkyl group, nitro group, halogen atom, C1-C6 alkylsulfonyl group and C1-C6 alkylthio group are preferable, and sulfo group is particularly preferable.

  When X is a carboxyanilino group, among the group of 20 substituents, a sulfo group, a carboxy group, a hydroxy group, and a sulfamoyl group are preferable.

  When X is a phosphonoanilino group, it is preferable that the group selected from the group of 20 substituents is not present.

  When X is a sulfonaphthylamino group, a sulfo group and a hydroxy group are preferred among the group of 20 substituents.

  When X is a carboxynaphthylamino group or a phosphononaphthylamino group, a group selected from the group of 20 substituents is preferably absent.

  Specific examples of X in the formula (1) include a sulfoanilino group such as 2-sulfoanilino, 3-sulfoanilino, 4-sulfoanilino, 2,4-disulfoanilino, 2,5-disulfoanilino, and 0 or one sulfo group. Those in which the sulfoanilino group further has one carboxy group (or the carboxyanilino group further has one sulfo group), such as 2-carboxy-4-sulfoanilino and 2-carboxy-5-sulfoanilino; 4 A compound having a sulfoanilino group further having one C1-C6 alkoxy group, such as methoxy-2-sulfoanilino, 4-ethoxy-2-sulfoanilino, 4-ethoxy-6-sulfoanilino; The sulfoanilino group further has one amino group A sulfoanilino group further having one mono-C1-C4 alkylamino group, such as 4-methylamino-5-sulfoanilino; a di-C1-C4 alkyl wherein the sulfoanilino group is further one, such as 4-dimethylamino-5-sulfoanilino Those having an amino group; those having a sulfoanilino group further having one C1-C6 alkyl group such as 2-methyl-5-sulfoanilino and 3-methyl-6-sulfoanilino; sulfoanilino such as 4-anilino-3-sulfoanilino A group further having one arylamino group; a sulfoanilino group further having one C1-C3 alkylcarbonylamino group, such as 4-acetylamino-2-sulfoanilino; 2-chloro-5-sulfoanilino, 3, Such as 5-dichloro-4-sulfoanilino Anilino group further having one or two halogen atoms; one more sulfoanilino group such as 4-methylsulfonyl-2-sulfoanilino, 4-methylsulfonyl-5-sulfoanilino, 4-hexylsulfonyl-2-sulfoanilino, etc. Those having a C1-C6 alkylsulfonyl group; those having a sulfoanilino group further having one C1-C6 alkylthio group, such as 4-methylthio-2-sulfoanilino and 4-hexylthio-2-sulfoanilino; 3-carboxy-4- Hydroxy-5-sulfoanilino, 2-hydroxy-5-nitro-3-sulfoanilino, 2-methoxy-4-nitro-5-sulfoanilino, 3-methyl-6-methoxy-4-sulfoanilino, 2-hydroxy-3-acetylamino Sulfo, such as -5-sulfoanilino Anilino group further having two kinds of groups selected from the group of 20 substituents; 2-carboxyanilino, 3-carboxyanilino, 4-carboxyanilino, 3,5-di A carboxyanilino group further having zero or one carboxy group, such as carboxyanilino; a carboxyanilino group further having one sulfamoyl group, such as 4-sulfamoyl-2-carboxyanilino; 3- A carboxyanilino group further having one hydroxy group, such as carboxy-4-hydroxyanilino; a carboxyanilino group substituted for said 20 groups, such as 4-hydroxy-3-sulfo-5-carboxyanilino Having two further two groups selected from the group of groups; 2-phosphonoanilino, 3-phosphonoanilino, A phosphonoanilino group such as phosphonoanilino; 4,8-disulfo-2-naphthylamino, 1,5-disulfo-2-naphthylamino, 3,6-disulfo-1-naphthylamino, 5,7-disulfo-2-naphthylamino 6,8-disulfo-2-naphthylamino, 3,6,8-trisulfo-1-naphthylamino, 3,6,8-trisulfo-2-naphthylamino and the like, wherein the sulfonaphthylamino group further has one or two sulfo Having a group; a sulfonaphthylamino group further having one hydroxy group, such as 5-hydroxy-7-sulfo-2-naphthylamino; 3,6-disulfo-8-hydroxy-1-naphthylamino, 8 -Chloro-3,6-disulfonaphthalen-1-ylamino, 6-nitro-4,8-disulfo-2-naphthylamino, etc. Two groups sulfo naphthyl amino group is selected from the group of substituents of the 20 groups, those having two more; and the like. Among these, 2-sulfoanilino, 3-sulfoanilino, 4-sulfoanilino, 2,4-disulfoanilino, 2,5-disulfoanilino, 3,6-disulfo-1-naphthylamino, 5,7-disulfo-2-naphthylamino, 6,8-disulfo-2-naphthylamino, 3,6,8-trisulfo-1-naphthylamino are preferred, and 4-sulfoanilino, 2,5-disulfoanilino, or 3,6,8-trisulfo-1-naphthylamino is preferred. More preferred is 2,5-disulfoanilino.

  In the formula (1), R represents a hydrogen atom, a sulfo group; a carboxy group; a phosphate group; a sulfamoyl group; a carbamoyl group; a hydroxy group; a C1-C6 alkoxy group; an amino group; C1-C6 alkylamino group; mono-C6-C10 arylamino group; di-C6-C10 arylamino group; C1-C3 alkylcarbonylamino group; ureido group; C1-C6 alkyl group; nitro group; cyano group; -C6 alkylsulfonyl group; Or an alkylthio group.

  Examples of the C1-C6 alkoxy group for R include a linear, branched or cyclic C1-C6, preferably C1-C4, more preferably a C1-C3 alkyl group. Among these, linear or branched ones are preferable, and linear ones are more preferable. Specific examples include straight chain such as methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexyloxy; isopropoxy, isobutoxy, sec-butoxy, t-butoxy, isopentyloxy, isohexyl Branched chain such as xyloxy; cyclic such as cyclopropoxy, cyclopentoxy, cyclohexyloxy; and the like. Among these, methoxy or ethoxy is preferable, and methoxy is particularly preferable.

  Examples of the mono-Cl-C4 alkylamino group in R include straight-chain or branched-chain groups, and the carbon number range is usually C1-C4, preferably C1-C3. Specific examples include straight chain such as methylamino, ethylamino, n-propylamino, and n-butylamino; branched chain such as isopropylamino, isobutylamino, sec-butylamino, and t-butylamino; Is mentioned.

  Examples of the di-C1-C4 alkylamino group in R include a dialkylamino group having two alkyl moieties independently exemplified as the monoalkylamino group. Specific examples include dimethylamino, diethylamino, methylethylamino and the like.

  Examples of the mono C6-C10 arylamino group in R include a mono C6-C10 aromatic amino group, preferably a phenylamino group or a naphthylamino group, and more preferably a phenylamino group.

  Examples of the di-C6-C10 arylamino group for R include a diarylamino group independently having two aryls mentioned for the monoarylamino group. Preferred are those having the same aryl, more preferably two phenyls, and specific examples include diphenylamino.

  Examples of the C1-C3 alkylcarbonylamino group for R include straight-chain or branched-chain groups, and straight-chain groups are preferred. Specific examples thereof include linear ones such as methylcarbonylamino (acetylamino), ethylcarbonylamino, and n-propylcarbonylamino; branched ones such as isopropylcarbonylamino.

  Examples of the C1-C6 alkyl group for R include linear, branched or cyclic C1-C6, preferably C1-C4, and more preferably C1-C3 alkyl groups. Among these, linear or branched ones are preferable, and linear ones are more preferable. Specific examples include straight chain such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl; isopropyl, isobutyl, Ssec-butyl, t-butyl, isopentyl, isohexyl, etc. Examples include branched ones; cyclic ones such as cyclopropyl, cyclopentyl and cyclohexyl; and the like. Of these, methyl is preferred.

  Examples of the halogen atom in R include a fluorine atom, a chlorine atom, and a bromine atom. A fluorine atom or a chlorine atom is preferable, and a chlorine atom is more preferable.

  Examples of the C1-C6 alkylsulfonyl group for R include a linear or branched C1-C6, preferably C1-C4, more preferably a C1-C3 alkylsulfonyl group, and a linear one is preferable. Specific examples include linear chains such as methanesulfonyl (methylsulfonyl), ethanesulfonyl (ethylsulfonyl), n-propanesulfonyl (n-propylsulfonyl), n-butylsulfonyl, n-pentylsulfonyl, and n-hexylsulfonyl. A branched chain such as isopropylsulfonyl and isobutylsulfonyl; and the like.

  Examples of the C1-C6 alkylthio group in R include a linear or branched C1-C6, preferably C1-C4, more preferably a Cl-C3 alkylthio group, and a linear one is preferable. Specific examples include straight chain such as methylthio, ethylthio, n-propylthio, n-butylthio, n-pentylthio, n-hexylthio; isopropylthio, isobutylthio, t-butylthio, isopentylthio, isohexylthio, etc. Or a branched chain of

  In the formula (1), the group F represents a phenyl group; or a 6-membered nitrogen-containing heteroaromatic group. Examples of the 6-membered nitrogen-containing heteroaromatic group include a nitrogen-containing heteroaromatic group containing one nitrogen atom. A specific example is pyridyl. In the 6-membered nitrogen-containing heteroaromatic ring, the position of bonding with the alkylene represented by “a” is not particularly limited, but it is preferable that the bonding is performed with a carbon atom adjacent to the nitrogen atom. That is, when the group F is pyridyl, the substitution position of the nitrogen atom is taken as the 1st position, and 2-pyridyl, 3-pyridyl, 4-pyridyl, and the like, which are bonded at a carbon atom adjacent to the nitrogen atom, Is preferred.

  In the formula (1), when the group F is a phenyl group, among the R, a hydrogen atom, a sulfo group, a carboxy group, a C1-C6 alkoxy group, a C1-C6 alkyl group, and a halogen atom are preferable, and a hydrogen atom, a sulfo group Group, carboxy group, methoxy group, methyl group, fluorine atom and chlorine atom are more preferred, and hydrogen atom, sulfo group and carboxy group are more preferred.

  In the formula (1), when the group F is a 6-membered nitrogen-containing heteroaromatic group, among the R, a hydrogen atom or a halogen atom is preferable, and a hydrogen atom is particularly preferable.

In the formula (1), the substitution position of R in the group F is not particularly limited. When the group F is a phenyl group, the bonding position with “(CH ₂ ) a” is defined as the 1st position, and the substitution position of R includes the 2nd, 3rd, or 4th position, and the 4th position is preferred. In addition, when the group F is a 6-membered nitrogen-containing heteroaromatic group, preferably pyridyl, the bonding position of “(CH ₂ ) a” and R is based on the nitrogen atom of the pyridine ring as the first position, the former being the second position, Are the 3rd, 4th, 5th and 6th positions, with the former being the 2nd and the latter being the 4th.

In the formula (1), a represents the repeating number of “(CH ₂ )”, that is, the length of alkylene, and is usually an integer of 1-6, preferably 1-4, more preferably 1-3, and still more preferably. Is an integer of 1-2, particularly preferably 1.

  In formula (1), b and c, and the sum of b and c are all average values. b is 0.00 or more and less than 3.90, c is 0.10 or more and less than 4.00, and the sum of b and c is an average value of 1.00 or more and less than 4.00. At this time, the nitrogen-containing heteroaromatic rings in rings A to D have an average value exceeding 0.00 and not more than 3.00, and similarly the benzene rings are not less than 1.00 and less than 4.00. Preferably, when the nitrogen-containing heteroaromatic ring in A to D is 0.20 or more and 2.00 or less and the benzene ring is 2.00 or more and 3.80 or less, b is 0.00 or more and 3.40 or less, and c Is 0.40 or more and 2.00 or less, and the sum of b and c is 2.00 or more and 3.80 or less. More preferably, when the nitrogen-containing heteroaromatic ring in rings A to D is 0.50 or more and 1.75 or less, and the benzene ring is 2.25 or more and 3.50 or less, b is 0.35 or more and 3.05 or less. , C is 0.45 or more and 1.90 or less, and the sum of b and c is 2.25 or more and 3.50 or less. More preferably, when the nitrogen-containing heteroaromatic ring in rings A to D is 0.75 or more and 1.50 or less, and the benzene ring is 2.50 or more and 3.25 or less, b is 0.70 or more and 2.75 or less. , C is 0.50 or more and 1.80 or less, and the sum of b and c is 2.50 or more and 3.25 or less. As b increases, ozone resistance tends to improve, but bronzing tends to occur easily. Taking into account ozone resistance and bronze resistance, the number of b and c is adjusted as appropriate to achieve a good balance. What is necessary is just to select a ratio.

  Note that each of the unsubstituted sulfamoyl group and the substituted sulfamoyl group represented by b and c is a group that is substituted on the benzene ring when the rings A to D are benzene rings, When A to D are 6-membered nitrogen-containing heteroaromatic rings, they are not substituted. In this specification, b, c, and the sum of b and c are all rounded off to the second digit by rounding off the third digit after the decimal point.

  In the above rings A to D, E, X, R, groups F, a, b and c, a compound in which preferable ones are combined is more preferable, and a compound in which more preferable ones are combined is more preferable. The same applies to preferable ones, combinations of preferable ones and more preferable ones, and the like.

  The dye represented by the general formula (1) can form a salt by utilizing sulfo, carboxy, phosphono and the like in the molecule. When forming a salt, the sulfo group, carboxy group, phosphono group and the like in the molecule preferably form a salt with each cation such as metal, ammonia or organic base.

  Examples of the metal include alkali metals and alkaline earth metals. Examples of the alkali metal include lithium, sodium, potassium and the like. Examples of the alkaline earth metal include calcium and magnesium.

  Examples of the organic base include organic amines, for example, C1-C3 alkylamines such as methylamine and ethylamine, mono-, di- or tri-C1-C4 alkanols such as monoethanolamine, diethanolamine and triethanolamine. Examples include amines.

  The second ink according to this embodiment includes a dye represented by the general formula (1) and a metal salt of a second metal ion, and the dye contained in the second ink is substantially composed of a metal salt of the second metal ion. It is preferable to become. This is because the solubility of the dye is improved.

  The second metal ion contained in the second ink as the counter ion of the first dye is preferably at least one of sodium ion and lithium ion. Thereby, the solubility of the first dye in the second ink can be improved.

  Particularly preferred compounds as the first dye are compounds having the following combinations (a) to (f). (A) The nitrogen-containing heteroaromatic rings in rings A to D are each independently a pyridine ring condensed at the 2-position and 3-position or at the 3-position and 4-position; or a condensed ring at the 2-position and 3-position Pyrazine ring is preferred. (B) As E, linear C2-C4 alkylene is preferable. (C) As X, as a substituent, sulfo group, carboxy group, hydroxy group, C1-C6 alkoxy group, amino group, mono C1-C4 alkylamino group, di-C1-C4 alkylamino group, C1-C3 alkylcarbonyl A sulfoanilino group which may have 0 or 2 substituents of one or two types selected from the group consisting of an amino group, a nitro group, a halogen atom, a C1-C6 alkylsulfonyl group and an alkylthio group; A carboxyanilino group optionally having 0 to 2 substituents of one or two types selected from the group consisting of a sulfo group, a carboxy group, a hydroxy group, and a sulfamoyl group; a phosphonoanilino group; The group may have 0 to 2 substituents of one or two types selected from a sulfo group and a hydroxy group. Sulfo naphthyl amino group; is preferred. (D) R is preferably a hydrogen atom; a sulfo group; a carboxy group; a C1-C6 alkoxy group; a C1-C6 alkyl group; or a halogen atom. (E) The group F is preferably a phenyl group; or a pyridyl group in which R is a hydrogen atom. (F) As a, 1 or 2 is preferable.

Specific examples of rings A to D, E, X, R, and group F, and the numbers of a, b, and c in the first dye are shown in Tables 1 to 4 below. The following examples are representative examples for specifically explaining the first dye, and the first dye is not limited to the following examples. In addition, when the nitrogen-containing heteroaromatic rings of rings A to D are pyridine rings, there are positional isomers of nitrogen atoms as will be described later, and it is obtained as a mixture of isomers when the first dye is synthesized. . These isomers are difficult to identify, and it is also difficult to identify isomers by analysis. For this reason, it is usually used as a mixture. The first dye of the present invention includes such a mixture. In the present specification, when a structural formula is used without distinguishing these isomers, a typical structural formula is described for convenience. In addition, about the number of b and c in a table | surface, in order to avoid complexity, the 2nd digit after a decimal point was rounded off and it described to the 1st digit. In Tables 1 to 4, “2,3-pyrido” represents a pyridine ring fused to a porphyrazine ring at the 2-position and 3-position, “benzo” represents a benzene ring fused to a porphyrazine ring, “ “2-Pyridyl” means that the bonding position with “(CH ₂ ) a” is position 2 with the nitrogen atom of the pyridine ring being position 1. As for “4-chloro” and the like in R, when the group F is a phenyl group, the bonding position with “(CH ₂ ) a” is the 1st position; when the group F is pyridyl, the nitrogen of the pyridine ring In the case where the atom is the 1st position, the substitution position of R in each is represented.

  The first dye can usually be used in the second ink without blending other pigments. However, in some cases, the first dye may be blended with a known cyan pigment within a range not impairing the effects of the present invention. Good. When blended with a known cyan pigment, the pigment blended is C.I. I. Numbered triphenylmethane dyes and phthalocyanine dyes can be used, but phthalocyanine dyes are preferred.

(B) Synthesis Method of Dye Hereinafter, the production method of the first dye will be described. The first dye can be obtained by reacting a porphyrazine compound represented by the following formula (2) with an organic amine represented by the following formula (3) in the presence of ammonia. Any of the porphyrazine compounds represented by the following formula (2) can be obtained by synthesizing a compound represented by the following formula (4) according to a known method or a similar method and then chlorosulfonylating the compound. it can.

  That is, the compound represented by the following formula (4) can be synthesized according to a known method disclosed in, for example, International Publication No. 2007/091631 and International Publication No. 2007/116933. These known documents do not disclose a production method relating to a compound in which the number of nitrogen-containing heteroaromatic rings in rings A to D is less than 1. However, when synthesizing by a known nitrile method or Weiler method, the inclusion ratio in the rings A to D can be changed by changing the blending ratio of the nitrogen-containing heteroaromatic dicarboxylic acid derivative used as a reaction raw material and the phthalic acid derivative. A compound represented by the formula (4) in which the number of nitrogen heteroaromatic rings is less than 1 can also be synthesized. The resulting compound represented by the formula (4) is a mixture of positional isomers relating to the substitution positions of nitrogen-containing heteroaromatic rings in rings A to D and the substitution positions of nitrogen atoms in the nitrogen-containing heteroaromatic rings. This is also as described in the known literature.

  In formula (4), rings A to D have the same meaning as in formula (1).

  The porphyrazine compound represented by the formula (2) is obtained by converting the compound represented by the formula (4) to chloroform according to a known method disclosed in the same international pamphlet as the synthesis of the compound represented by the formula (4). It can be obtained by sulfonylation. The chlorosulfonyl group in the formula (2) is introduced on the benzene ring in the rings A to D, and is not introduced when the rings A to D correspond to nitrogen-containing heteroaromatic ring groups. Since one chlorosulfonyl group is usually introduced on the benzene ring, the number of n in the formula (2) is not more than the number of benzene rings in the rings A to D. Therefore, the number “n” of chlorosulfonyl groups in the formula (2) is 1.00 or more and less than 4.00 corresponding to the number of benzene rings of the porphyrazine compound represented by the formula (2). As another method for synthesizing the porphyrazine compound represented by the formula (2), a sulfo group can be formed by condensing and closing a sulfophthalic acid having a sulfo group and a nitrogen-containing heteroaromatic dicarboxylic acid derivative such as quinolinic acid in advance. And a method of synthesizing a porphyrazine compound having the compound and then converting the sulfo group into a chlorosulfonyl group with an appropriate chlorinating agent such as thionyl chloride. In this case, the sulfo group introduced onto the porphyrazine compound represented by the formula (2) by selecting the substitution position of the sulfo group of the sulfophthalic acid as the synthesis raw material from the 3-position and the 4-position. The replacement position of can be controlled. That is, when 3-sulfophthalic acid is used, a sulfo group can be selectively introduced at the “α” position in the following formula (5), and when 4-sulfophthalic acid is used, it can be selectively introduced at the “β” position. . In the present specification, unless otherwise specified, the term “α-position of the porphyrazine ring” or “β-position of the porphyrazine ring” means a corresponding position in the following formula (5).

On the other hand, the organic amine represented by the formula (3) can also be produced by a known method. For example, 0.9 to 1.2 mol of a substituted aniline or substituted naphthylamine corresponding to X and 1 mol of 2,4,6-trichloro-S-triazine (cyanuric chloride) are added to an alkali metal water such as sodium hydroxide. The reaction solution is adjusted to approximately pH 1 to 5 with an oxide and reacted under conditions of 0 to 40 ° C. and 2 to 12 hours to obtain a primary condensate. Next, 0.9 to 1.5 moles of an amine “H ₂ N— (CH ₂ ) aF—R” is added, and the reaction solution is about pH 5 to 10 with an alkali metal hydroxide such as sodium hydroxide. And a secondary condensate is obtained by reacting at 5 to 80 ° C. for 0.5 to 12 hours. 1 mol of the obtained secondary condensate and 1 to 50 mol of an alkylene diamine corresponding to E (an amine “H ₂ N-E-NH ₂ ”) are about pH 9 to 12, 5 to 90 ° C., 0 The organic amine represented by the formula (4) is obtained by reacting for 5 to 8 hours. For pH adjustment of each condensation reaction, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; The order of condensation is appropriately determined according to the reactivity of various compounds condensed with cyanuric chloride, and is not limited to the above order.

  The reaction between the porphyrazine compound represented by the formula (2) and the organic amine represented by the formula (3) is about pH 8 to 10, 5 to 70 ° C., 1 to The reaction is carried out for 20 hours to obtain the target first dye represented by the formula (1). “Ammonia” used in the reaction usually means aqueous ammonia. However, any chemical substance that generates ammonia by neutralization or decomposition can be used. Examples of chemical substances that generate ammonia include those that generate ammonia by neutralization, such as ammonium salts such as ammonium chloride and ammonium sulfate; those that generate ammonia by thermal decomposition of urea and the like; However, it is not limited to these. As the “ammonia”, aqueous ammonia is preferable. Concentrated aqueous ammonia (usually commercially available as approximately 28% aqueous ammonia) or a solution diluted with water as necessary may be used. It ’s fine.

  The amount of the organic amine represented by the formula (3) is usually the theoretical value [in order to obtain the value of c in the target first dye with respect to 1 mol of the porphyrazine compound represented by the formula (2). The required number of moles of the organic amine represented by the formula (3) in the calculation is 1 mole or more, but it depends on the reactivity of the organic amine used and the reaction conditions, and is not limited thereto. Usually, it is about 1 to 3 mol, preferably about 1 to 2 mol of the theoretical value.

  The first dye is synthesized from the above formula (2) and the compound represented by formula (3) under reaction conditions that do not require anhydrous conditions. For this reason, a compound in which the chlorosulfonyl group in the formula (2) is partially hydrolyzed by water mixed in the reaction system and converted to sulfonic acid is by-produced. It is theoretically considered to be mixed in one dye. However, in mass spectrometry, it is difficult to distinguish an unsubstituted sulfamoyl group from a sulfo group. In the present invention, the chlorosulfonyl in the formula (2) other than the one reacted with the organic amine represented by the formula (3) All the groups are described as being converted to unsubstituted sulfamoyl groups.

Furthermore, in a part of the first dye, an impurity in which a copper porphyrazine ring (Pz) forms a dimer (for example, Pz-L-Pz) or a trimer is formed via a divalent linking group (L). It may be produced as a by-product and mixed in the reaction product. Examples of the divalent linking group represented by _{L -SO 2 -, - SO 2} -NH-SO 2 - or the like it has, by-products of these two L are combined in the case of a trimer Sometimes formed.

  The first dye obtained as described above can be isolated as a solid by filtration separation or the like from the reaction solution in the final step in the synthesis reaction by precipitation or acid precipitation. The salting out is preferably performed, for example, in the range of acidic to alkaline, preferably pH 1-11. Although the temperature at the time of salting out is not specifically limited, It is preferable to salt out by adding sodium chloride etc. after heating to 40-80 degreeC normally, Preferably it is 50-70 degreeC.

  The 1st dye synthesize | combined by the said method is obtained as a free acid or its salt. Examples of the method for isolating the first dye as a free acid include acid precipitation. In addition, as a method of isolating as a salt, when salting out or a desired salt cannot be obtained by salting out, for example, the obtained salt is converted into a free acid, and then a desired organic or inorganic base is added. For example, a known salt exchange method or the like.

  As an example, a method for converting the dye represented by the general formula (1) into a lithium salt will be described below. After reacting the porphyrazine compound represented by the formula (2) with the organic amine represented by the formula (3), sodium chloride is added, and salting out and filtration are performed. The sodium salt of the dye represented by (1) is obtained. Next, water and hydrochloric acid are added to the sodium salt, and acid precipitation and filtration are performed to obtain a free acid of the dye represented by the general formula (1). Furthermore, the lithium salt of the dye represented by the general formula (1) can be obtained by adding water and lithium hydroxide to the free acid. Moreover, as a different method to make a lithium salt, a salt exchange reaction using a sodium salt of a dye represented by the general formula (1) and lithium chloride can be mentioned.

1.3. Physical Properties of Each Ink When the ink set according to the present embodiment is used in an ink jet recording apparatus, the viscosity of each ink (first ink and second ink) at 20 ° C. is 2 mPa · s or more and 10 mPa · s or less, respectively. It is preferably 3 mPa · s or more and 6 mPa · s or less. If the viscosity at 20 ° C. is within the above range, each ink can be suitably used in an ink jet recording apparatus because it is ejected in an appropriate amount from the nozzle and can further reduce the occurrence of flight bending and scattering. The viscosity of each ink can be measured by maintaining the temperature of the ink at 20 ° C. using a vibration viscometer VM-100AL (manufactured by Yamaichi Electronics Co., Ltd.).

2. Droplet Discharge Device A droplet discharge device according to an embodiment of the present invention includes the above-described ink set including the first ink and the second ink, and a nozzle hole for discharging the first ink and the second ink. It has a nozzle surface and a wipe member for wiping the nozzle surface.

  Hereinafter, a droplet discharge device according to an embodiment of the present invention will be described with reference to FIGS. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size. In this embodiment, an ink jet printer (hereinafter simply referred to as “printer”) is exemplified as the droplet discharge device according to the present invention.

  FIG. 1 is a perspective view illustrating a configuration of a printer 1 according to the present embodiment. The printer 1 represents a serial printer.

  As shown in FIG. 1, a printer 1 includes an inkjet head 2 and a carriage 4 on which an ink cartridge 3 is detachably mounted, and a platen 5 disposed below the inkjet head 2 and to which a recording medium 6 is conveyed. And a carriage moving mechanism 7 for moving the carriage 4 in the medium width direction of the recording medium 6 and a medium feeding mechanism 8 for conveying the recording medium 6 in the medium feeding direction. In addition, the printer 1 includes a control device CONT that controls the operation of the entire printer 1. The medium width direction is the main scanning direction (head scanning direction). The medium feeding direction is a sub-scanning direction (a direction orthogonal to the main scanning direction).

  The ink cartridge 3 is not limited to the one mounted on the carriage 4 as in the present embodiment, but instead, for example, a type that is mounted on the housing side of the printer 1 and is supplied to the inkjet head 2 via the ink supply tube. It may be. The ink cartridge 3 contains a first ink, a second ink, a third ink, and a fourth ink, respectively. The ink set of the printer 1 includes a first ink, a second ink, a third ink, and a fourth ink. The third ink and the fourth ink may be an ink having the same composition as at least one of the first ink and the second ink, or may be an ink having a composition different from that of the first ink and the second ink.

  The carriage 4 is attached in a state of being supported by a guide rod 9 which is a support member installed in the main scanning direction. The carriage 4 is moved in the main scanning direction along the guide rod 9 by the carriage moving mechanism 7.

  The linear encoder 10 detects the position of the carriage 4 in the main scanning direction with a signal. This detected signal is transmitted to the control device CONT as position information. The control device CONT recognizes the scanning position of the ink jet head 2 based on the position information from the linear encoder 10 and controls the recording operation (discharge operation) and the like by the ink jet head 2. Further, the control device CONT is configured to be able to variably control the moving speed of the carriage 4.

  FIG. 2 is a schematic diagram showing the arrangement of the nozzle holes 17 provided in the inkjet head 2 in the present embodiment.

  As shown in FIG. 2, the ink jet head 2 has a nozzle surface 21A provided with a plurality of nozzle holes 17 for ejecting ink. A nozzle row 16 is formed for each of the plurality of nozzle holes 17 on the nozzle surface 21 </ b> A which is also an ink ejection surface. In each nozzle row 16, for example, inks having different compositions can be ejected. In the present embodiment, four rows corresponding to the ink composition, that is, the nozzle row 16 (first ink), the nozzle row 16 (second ink), the nozzle row 16 (third ink), and the nozzle row 16 (fourth ink). ) Is provided. Each nozzle row 16 is configured by, for example, 180 nozzle holes 17.

  FIG. 3 is a partial cross-sectional view showing the internal configuration of the inkjet head 2 in the present embodiment.

  As shown in FIG. 3, the inkjet head 2 includes a head main body 18 and a flow path forming unit 22 connected to the head main body 18. The flow path forming unit 22 includes a vibration plate 19, a flow path substrate 20, and a nozzle substrate 21, and forms a common ink chamber 29, an ink supply port 30, and a pressure chamber 31. Furthermore, the flow path forming unit 22 includes an island portion 32 that functions as a diaphragm portion, and a compliance portion 33 that absorbs pressure fluctuation in the common ink chamber 29. In the head main body 18, an accommodation space 23 for accommodating the drive unit 24 together with the fixing member 26 and an internal flow path 28 for guiding ink to the flow path forming unit 22 are formed.

  According to the above configuration, that is, the piezo-type inkjet head 2, when a drive signal is input to the drive unit 24 via the cable 27, the piezoelectric element 25 expands and contracts. As a result, the diaphragm 19 is deformed (moved) in a direction toward and away from the pressure chamber 31. For this reason, the volume of the pressure chamber 31 changes and the pressure of the pressure chamber 31 containing ink fluctuates. Ink is ejected from the nozzle hole 17 due to the fluctuation of the pressure.

  Returning to FIG. 1, a home position serving as a scanning start point of the inkjet head 2 is set in a region outside the platen 5 in the movement range of the inkjet head 2. A maintenance unit 11 is provided at the home position. The maintenance unit 11 performs a moisturizing operation for capping the ink jet head 2 with the cap member 12 other than the printing operation to suppress ink evaporation, and preliminarily ejecting the ink to the cap member 12 from each nozzle hole 17 of the ink jet head 2. Prevention of clogging of the nozzle hole 17 with thickened ink, adjustment of the meniscus of the nozzle hole 17 to normally discharge ink from the inkjet head 2, and suction (not shown) after the inkjet head 2 is capped with the cap member 12. A suction operation (head cleaning) for normally ejecting ink from the ink-jet head 2 by adjusting the meniscus by forcibly sucking ink with increased viscosity or adhering dust from each nozzle hole 17 by driving the pump; Nozzle of head 2 21A (see FIG. 2) is wiped with the wiping member 13 to remove ink adhering to the nozzle hole 17 or thickened ink, or to destroy the meniscus in the nozzle hole 17 and readjust the meniscus. And a wiping operation for performing the purge process.

  The first ink and the second ink have the above-described composition. For this reason, even if the first ink and the second ink are mixed on the nozzle surface 21A by wiping, the aggregation of the pigment is less likely to occur, so that the clogging of the nozzle holes 17 due to the aggregation of the pigment can be reduced. As a result, the printer 1 has good ejection stability.

3. EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

3.1. Synthesis of dye (Production Example 1)
Dye A-C was synthesize | combined by the below-mentioned process 1-5. Hereinafter, “parts” and “%” are based on mass unless otherwise specified. Moreover, each operation, such as reaction and crystallization, was performed under stirring unless otherwise specified. Further, “trade names Leocol (registered trademark) TD-90 and TD-50” used in the synthesis reaction are all surfactants manufactured by Lion Corporation. When the required amount of the target compound was not obtained in one synthesis reaction, the same reaction was repeated until the required amount was obtained.

  In addition, all the dyes synthesize | combined in the manufacture example are the mixtures containing an isomer etc. as mentioned above, and this isomer etc. are also included about a yield. Unless otherwise specified, the substitution positions of the unsubstituted and substituted sulfamoyl groups in the dye are a mixture of those substituted at the α-position and β-position of the porphyrazine ring.

(Process 1)
Synthesis of a compound in which 1.20 of rings A to D in formula (4) is a pyridine ring condensed at the 2-position and 3-position, and the remaining 2.80 is a benzene ring.

  To 375 parts of sulfolane, 31.11 parts of phthalic anhydride, 15.04 parts of quinolinic acid, 108 parts of urea, 10.1 parts of copper (II) chloride and 1.5 parts of ammonium molybdate are added, and the temperature is raised to 200 ° C. And reacted at the same temperature for 5 hours. After completion of the reaction, the reaction mixture was cooled to 65 ° C., 50 parts of DMF (N, N-dimethylformamide) was added, and the precipitated solid was separated by filtration. The obtained solid was washed with 50 parts of DMF to obtain 75.1 parts of a wet cake. The obtained wet cake was added to 450 parts of DMF, heated to 110 ° C., and reacted at the same temperature for 1 hour. The precipitated solid was separated by filtration and washed with 200 parts of water to obtain a wet cake. The obtained wet cake was added to 450 parts of 5% hydrochloric acid, heated to 60 ° C., and stirred at the same temperature for 1 hour. The precipitated solid was separated by filtration and washed with 200 parts of water to obtain a wet cake. The obtained wet cake was added to 450 parts of 5% aqueous ammonia, stirred at 60 ° C. for 1 hour, the precipitated solid was separated by filtration and washed with 200 parts of water to obtain 78.6 parts of a wet cake. The obtained wet cake was dried at 80 ° C. to obtain 24.9 parts of the target compound as a blue solid.

(Process 2)
Synthesis of a compound in which 1.20 of the rings A to D in the formula (2) is a pyridine ring condensed at the 2-position and the 3-position, the remaining 2.80 is a benzene ring, and n is 2.80.

  At room temperature, 5.8 parts of the compound of the formula (4) obtained in “Step 1” was gradually added to 46.2 parts of chlorosulfonic acid so as not to exceed 60 ° C., and then at 140 ° C. for 4 hours. Reacted. The obtained reaction solution was cooled to 70 ° C., 17.9 parts of thionyl chloride was added dropwise over 30 minutes, and the mixture was further reacted at 70 ° C. for 3 hours. The reaction solution was cooled to 30 ° C. or lower, slowly poured into 800 parts of ice water, the precipitated solid was separated by filtration, and washed with 200 parts of cold water to obtain 38.2 parts of the target compound wet cake.

(Process 3)
Synthesis of organic amine represented by the following formula (6).

  Cyanuric chloride (18.4 parts) and Leocol TD-90 (0.05 parts) were added to 100 parts of ice water, followed by stirring at 10 ° C. or lower for 30 minutes. Next, 31.7 parts of 2,5-disulfoaniline (use a commercial product having a purity of 88.4%) was added, and the pH was adjusted to 2.0 to 3.0 with a 10% aqueous sodium hydroxide solution at 0 to 10 ° C. for 2 hours. Reaction was performed at 25-30 degreeC for 1 hour. Next, 10.9 parts of benzylamine was added to the reaction solution, and the reaction was carried out at 25 to 30 ° C. for 1 hour and at 30 to 40 ° C. for 1 hour while adjusting the pH to 7.0 to 8.0 with a 10% aqueous sodium hydroxide solution. A reaction solution containing a condensate was obtained.

  The reaction solution containing the secondary condensate obtained as described above was gradually added to an aqueous solution obtained by adding 60.1 parts of ethylenediamine to 120 parts of ice and stirred at room temperature for 1 hour. To this solution, 150 parts of ice and 200 parts of concentrated hydrochloric acid were added to adjust the pH to 1.0. At this time, the liquid volume was 700 parts. To this reaction solution, 140 parts of sodium chloride was added and stirred overnight to precipitate a solid. The precipitated solid was separated by filtration to obtain 70.0 parts of a wet cake. The obtained wet cake was added to 280 parts of water and dissolved with 10% aqueous sodium hydroxide solution to pH 9.0. At this time, the liquid volume was 360 parts. The solution was adjusted to pH 1.0 with concentrated hydrochloric acid, 70 parts of sodium chloride was added, and the mixture was stirred overnight to precipitate a solid. The precipitated solid was separated by filtration to obtain 60.3 parts of a wet cake. The obtained wet cake was added to a mixed solvent of 255 parts of methanol and 45 parts of water and stirred at 50 ° C. for 1 hour, and then the precipitated solid was separated by filtration to obtain 50.3 parts of a wet cake. The obtained wet cake was dried to obtain a white powder of 15.3 parts of the organic amine represented by the target formula (6).

(Process 4)
Dye represented by the following formula (7) [Dye in which 1.20 of the rings A to D in the following formula (7) is a pyridine ring condensed at the 2-position and 3-position, and the remaining 2.80 is a benzene ring] Synthesis of.

  38.2 parts of the wet cake obtained in the above “Step 2” was added to 200 parts of ice water, and the mixture was suspended by stirring at 5 ° C. or less. 10 minutes later, a solution obtained by dissolving 7.4 parts of the organic amine of the formula (6) obtained in “Step 3” in a mixed solution of 1.5 parts of 28% aqueous ammonia and 40 parts of water while maintaining the temperature at 10 ° C. or lower. Was added to this suspension and reacted with 28% aqueous ammonia while maintaining pH 9.0. While maintaining the same pH, the temperature was raised to 20 ° C., and the reaction was further continued overnight at the same temperature. The liquid volume at this time was 300 parts.

  The temperature of the reaction solution was raised to 50 ° C., 55.0 parts of sodium chloride was added and stirred for 10 minutes, the pH was adjusted to 1.0 with concentrated hydrochloric acid, the precipitated solid was separated by filtration, and 100 parts of a 20% sodium chloride aqueous solution. To obtain 27.1 parts of a wet cake. The obtained wet cake was added to 191 parts of water and adjusted to pH 9.0 with 25% aqueous sodium hydroxide solution to obtain a solution. The liquid volume at this time was 270 parts. The temperature of this solution was raised to 50 ° C., 54 parts of sodium chloride was added and stirred for 30 minutes, then adjusted to pH 4.0 with concentrated hydrochloric acid, the precipitated solid was separated by filtration, and washed with 100 parts of a 20% aqueous sodium chloride solution. 21.4 parts of a wet cake were obtained. The obtained wet cake was added to a mixed liquid of 160 parts of isopropyl alcohol and 40 parts of water and stirred at 50 ° C. for 1 hour, and then the precipitated solid was separated by filtration to obtain 15.7 parts of a wet cake. The obtained wet cake was dried to obtain 11.2 parts of a dye (free acid) of the above formula (7) as a blue powder.

(Step 5) Preparation of salt comprising dye of formula (7) The dye of formula (7) obtained as described above is treated by a conventional method, and dye A (lithium salt of dye of formula (7)), Dye B (sodium salt of dye of formula (7)), Dye C (potassium salt of dye of formula (7)), Dye (mixed salt of lithium salt and sodium salt of dye of formula (7)), Dye E (A mixed salt of a lithium salt and a potassium salt of the dye of the formula (7)) was obtained.

3.2. Ink preparation 3.2.1. Preparation of Pigment Ink (1) Preparation of Pigment Dispersion Add 20 parts by mass of black pigment and 80 parts by mass of ion-exchanged water as a pigment, and after mixing and stirring, using a sand mill (manufactured by Yaskawa Seisakusho Co., Ltd.), zirconia beads (A diameter of 1.5 mm) and a dispersion treatment were performed for 6 hours. Then, the pigment dispersion liquid was obtained by isolate | separating a zirconia bead with a separator.

(2) Preparation of Pigment Ink Next, each component was mixed and stirred at the blending amounts shown in Table 5, and pressure filtration was performed with a membrane filter having a pore size of 10 μm to obtain pigment ink A and pigment ink B. In addition, the unit described in Table 5 is mass%.

  Further, the viscosity of each pigment ink was measured by maintaining the temperature of the ink at 20 ° C. using a vibration viscometer VM-100AL (manufactured by Yamaichi Electronics Co., Ltd.). The viscosity of each pigment ink is also shown in Table 5.

3.2.2. Preparation of dye ink Each component was mixed and stirred in the blending amounts shown in Table 5, and pressure filtration was performed with a membrane filter having a pore size of 1.0 μm to obtain dye ink A, dye ink B, and dye ink C.

  Moreover, the viscosity of each dye ink was measured by maintaining the temperature of the ink at 20 ° C. using a vibration viscometer VM-100AL (manufactured by Yamaichi Electronics Co., Ltd.). The viscosity of each dye ink is also shown in Table 5.

Each component in Table 5 is as follows. As the black pigment A, a product obtained by treating a product name Printex 30 manufactured by Evonik Degussa Co., Ltd. according to a conventional method to form a potassium salt was used. Moreover, the black pigment B used the thing made into the sodium salt by processing Ebonic Degussa Co., Ltd. product name Printex 30 by the conventional method.
(Pigment)
・ Black pigment A (potassium salt)
・ Black pigment B (sodium salt)
(dye)
Dye A (lithium salt of the compound represented by the above formula (7))
Dye B (sodium salt of the compound represented by the above formula (7))
Dye C (potassium salt of the compound represented by the above formula (7))
Dye D (mixed salt of lithium salt and sodium salt of the compound represented by the above formula (7); Li: Na = 8: 2)
Dye E (mixed salt of lithium salt and potassium salt of the compound represented by the above formula (7); Li: K = 5: 5)
(Penetration enhancer)
・ Triethylene glycol monobutyl ether (humectant)
・ 1,2-Hexanediol ・ Glycerin ・ Triethylene glycol ・ Trimethylolpropane ・ 2-Pyrrolidone (surfactant)
-Acetylene glycol surfactant A (trade name “Orphine E1010”, manufactured by Nissin Chemical Industry Co., Ltd.)
Acetylene glycol surfactant B (trade name “Surfinol 104”, manufactured by Air Products and Chemicals Inc.)
(PH adjuster)
・ Triethanolamine ・ Potassium hydroxide (water)
・ Ion exchange water

3.3. Evaluation test 3.3.1. Measurement of conductivity The conductivity at 20 ° C. of each pigment ink and each dye ink was measured by a conductivity meter DS-52 (trade name, HORIBA, Ltd.). The measurement results are also shown in Table 5.

3.3.2. Evaluation of ejection stability Each pigment ink and each dye ink were filled in a nozzle row of an inkjet printer PX-B500 (trade name, manufactured by Seiko Epson Corporation). Of these inks, one type of pigment ink and one type of dye ink are selected, (a) check printing using the selected pigment ink and dye ink, and (b) nozzle surface suction operation (head cleaning). The nozzle surface wiping, (c) check printing using the selected pigment ink and dye ink, and (d) leaving the ink jet printer for 24 hours were performed 10 cycles in this order. .

Thereafter, the selected pigment ink and dye ink were ejected from the nozzles, check printing was performed, and the ejection stability was evaluated by confirming the presence or absence of nozzle omission and ink flight bending. The evaluation results are shown in Table 6. The classification of evaluation criteria is as follows.
“○”: No nozzle missing or ink flying bent “×”: No nozzle missing or ink flying bent

3.4. Evaluation results Table 6 shows the results of the above evaluation tests.

  In each of the ink sets of Examples 1 to 4 in Table 6, the ultimate equivalent conductivity of the metal ion (first metal ion) contained in the pigment ink is the ultimate equivalent of the metal ion (second metal ion) contained in the dye ink. Greater than conductivity. Therefore, the discharge stability test showed that there were no nozzle omissions or flight bends. As a result, it was shown that even when the pigment ink and the dye ink are mixed, aggregation of the pigment hardly occurs.

  On the other hand, in each of the ink sets of Comparative Examples 1 to 4 in Table 6, the ultimate equivalent conductivity of the metal ion (first metal ion) contained in the pigment ink is that of the metal ion (second metal ion) contained in the dye ink. Below the equivalent equivalent conductivity. For this reason, in the discharge stability test, nozzle missing and flight bending occurred. Thus, it was shown that pigment aggregation occurred due to the mixing of the pigment ink and the dye ink. In addition, the aggregation of the pigment occurred frequently when the nozzle surface was wiped, and also occurred when the splashes of the dye ink adhered to the nozzle holes for discharging the pigment ink when the dye ink was discharged.

  The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Inkjet head, 3 ... Ink cartridge, 4 ... Carriage, 5 ... Platen, 6 ... Recording medium, 7 ... Carriage moving mechanism, 8 ... Medium feed mechanism, 9 ... Guide rod, 10 ... Linear encoder, DESCRIPTION OF SYMBOLS 11 ... Maintenance unit, 12 ... Cap member, 13 ... Wipe member, 16 ... Nozzle row, 17 ... Nozzle hole, 18 ... Head body, 19 ... Vibration plate, 20 ... Flow path substrate, 21 ... Nozzle substrate, 21A ... Nozzle surface , 22 ... flow path forming unit, 23 ... accommodating space, 24 ... drive unit, 25 ... piezoelectric element, 26 ... fixing member, 27 ... cable, 28 ... internal flow path, 29 ... common ink chamber, 30 ... ink supply port, 31 ... Pressure chamber, 32 ... Island part, 33 ... Compliance part, CONT ... Control device

Claims (6)

Water, a pigment and a first ink containing a first metal ion as a counter ion of the pigment;
Water, a dye represented by the following general formula (1), and a second ink containing a second metal ion as a counter ion of the dye;
Have
The ultimate equivalent conductivity [S · cm ² / eq] of the first metal ion described in (Condition 1) or (Condition 2) below is the second metal described in (Condition 3) or (Condition 4) below. An ink set that is larger than the ultimate equivalent conductivity [S · cm ² / eq] of ions.
(Condition 1) When the first metal ion is composed of a single metal ion, the ultimate equivalent conductivity of the first metal ion is the ultimate equivalent conductivity of the single metal ion (Condition 2) the first When the metal ions are composed of two or more kinds of metal ions, the ultimate equivalent conductivity of the first metal ions is the average ultimate equivalent conductivity of the two or more kinds of metal ions (Condition 3). When the ion is composed of a single metal ion, the ultimate equivalent conductivity of the second metal ion is the ultimate equivalent conductivity of the single metal ion (Condition 4). The second metal ion is a metal of two or more types. When it consists of ions, the ultimate equivalent conductivity of the second metal ion is the average ultimate equivalent conductivity of the two or more metal ions.

(In the formula (1),
Rings A to D represented by broken lines each independently represent a benzene ring or a 6-membered nitrogen-containing heteroaromatic ring condensed to a porphyrazine ring, and the average number of nitrogen-containing heteroaromatic rings is 0.00. Exceeding 3.00 and the remainder is a benzene ring,
E represents C2-C12 alkylene;
X is a sulfo group, carboxy group, phosphate group, sulfamoyl group, carbamoyl group, hydroxy group, C1-C6 alkoxy group, amino group, mono C1-C4 alkylamino group, di-C1-C4 alkylamino group as a substituent. Mono-C6-C10 arylamino group, di-C6-C10 arylamino group, C1-C3 alkylcarbonylamino group, ureido group, C1-C6 alkyl group, nitro group, cyano group, halogen atom, C1-C6 alkylsulfonyl group, And a sulfoanilino group, a carboxyanilino group, a phosphonoanilino group, a sulfonaphthylamino group, a carboxynaphthylamino group, or one or more kinds of substituents selected from the group consisting of C1-C6 alkylthio groups, A phosphononaphthylamino group,
R represents a hydrogen atom; a sulfo group; a carboxy group; a phosphate group; a sulfamoyl group; a carbamoyl group; a hydroxy group; a C1-C6 alkoxy group; an amino group; a mono C1-C6 alkylamino group; Diarylamino group; C1-C3 alkylcarbonylamino group; ureido group; C1-C6 alkyl group; nitro group; cyano group; halogen atom; C1-C6 alkylsulfonyl group; or alkylthio group;
Group F represents a phenyl group; or a 6-membered nitrogen-containing heteroaromatic group;
a represents an integer of 1 to 6,
b is an average value of 0.00 or more and less than 3.90,
c is an average value of 0.10 or more and less than 4.00,
The sum of b and c is an average value of 1.00 or more and less than 4.00. ) In claim 1,
The ink set, wherein the first metal ion is at least one of sodium ion and lithium ion. In claim 1 or claim 2,
The ink set, wherein the second metal ion is at least one of potassium ion and sodium ion. In any one of Claims 1 thru | or 3,
In the general formula (1),
The nitrogen-containing heteroaromatic rings in rings A to D are each independently a pyridine ring fused at the 2-position and the 3-position, or the 3-position and the 4-position; or a pyrazine ring fused at the 2-position and the 3-position ,
E is a linear C2-C4 alkylene,
X is a substituent such as sulfo group, carboxy group, hydroxy group, C1-C6 alkoxy group, amino group, mono C1-C4 alkylamino group, di-C1-C4 alkylamino group, C1-C3 alkylcarbonylamino group, nitro A sulfoanilino group which may have 0 or 2 substituents of one or two types selected from the group consisting of a group, a halogen atom, a C1-C6 alkylsulfonyl group, and a C1-C6 alkylthio group; A carboxyanilino group optionally having 0 to 2 substituents of one or two types selected from the group consisting of a sulfo group, a carboxy group, a hydroxy group, and a sulfamoyl group; a phosphonoanilino group; The group may have 0 to 2 substituents of one or two types selected from a sulfo group and a hydroxy group. Sulfo-naphthyl amino group; a and,
R is a hydrogen atom; a sulfo group; a carboxy group; a C1-C6 alkoxy group; a C1-C6 alkyl group; or a halogen atom;
A group F is a phenyl group; or a pyridyl group in which R is a hydrogen atom;
An ink set in which a is an integer of 1 or 2. In any one of Claims 1 thru | or 4,
In the general formula (1),
The nitrogen-containing heteroaromatic rings in rings A to D are each independently a pyridine ring condensed at the 2-position and 3-position;
E is ethylene,
X is a sulfoanilino group optionally having 0 or 1 sulfo group as a substituent; or a sulfonaphthylamino group having 2 sulfo groups as a substituent,
R is a hydrogen atom, a sulfo group, or a carboxy group,
The group F is a phenyl group, or a pyridyl group in which R is a hydrogen atom,
a is an integer of 1;
b is an average value of 0.00 or more and less than 3.90,
c is an average value of 0.10 or more and less than 4.00,
The sum of b and c is an ink set having an average value of 1.00 or more and less than 4.00. An ink set comprising the first ink and the second ink according to any one of claims 1 to 5,
A nozzle surface having nozzle holes for discharging the first ink and the second ink;
A wipe member for wiping the nozzle surface;
A droplet discharge device.

Images