Azo metal complex dyes and ink compositions containing them

Abstract

The present invention provides an azo metal complex dye that has sufficient solubility in organic solvents for practical use, exhibits good black color, and maintains its blackness without discoloration even when dissolved in ketone and / or alcohol-based solvents and stored at high temperatures for extended periods, as well as an ink composition containing the same. [Solution] The azo metal complex dye includes a disazo-monoazo metal complex dye represented by formula (1). The ink composition includes the azo metal complex dye and an organic solvent. TIFF2026088907000090.tif66170 (In the formula, A + (It is a quaternary ammonium cation.)

Description

[Technical Field]

[0001] The present invention relates to an azo metal complex dye that exhibits black color when contained in an ink composition, and to an ink composition that remains black when containing the dye. [Background technology]

[0002] Ink compositions are used to print or draw on recording media using inkjet printers, writing instruments, and recorders. In particular, ink compositions for continuous inkjet (CIJ) printers, which are widely used in industrial fields, are prepared to have high electrical conductivity due to the CIJ printer's configuration of charging and deflecting the ink composition before ejecting it onto the recording media, and to ensure good ink adhesion even on smooth, non-absorbent surfaces such as glass plates, metal plates, and plastic plates. Such ink compositions contain a colorant, an organic solvent, and a resin that is a fixative soluble in the organic solvent.

[0003] Pigments and dyes are examples of colorants included in ink compositions. Among colorants, black colorants are in particularly high demand. However, while black pigments are less susceptible to discoloration from light and heat, they have poor color development and can aggregate in ink compositions, resulting in poor storage stability. On the other hand, black dyes have high solubility in organic solvents and excellent color development and storage stability, but they deteriorate and discolor from heat and light, resulting in poor heat resistance and light resistance. Therefore, metal complex dyes that exhibit black color while maintaining the same high solubility in organic solvents as black dyes, and possessing the high heat resistance and light resistance of black pigments, are used as black colorants.

[0004] Furthermore, in addition to ketone-based organic solvents such as acetone and methyl ethyl ketone, which have been used conventionally, alcohol-based organic solvents such as ethanol and ethylene glycol, and ether-based organic solvents such as propylene glycol monoalkyl ether are also being used as organic solvents in ink compositions, from the perspective of environmental protection and ensuring safety for human health in recent years.

[0005] As black dyes with excellent solubility in alcoholic organic solvents, for example, amine salts of azochrome complex dyes are known. Specific examples of such azochrome complex dyes include CISOLVENT BLACK 23, 27, 28, 29, 35, and 45. Furthermore, Patent Document 1 discloses an azochrome complex dye that exhibits black color and is soluble in acetone.

[0006] However, because azochrome complex dyes contain chromium, a heavy metal, their use is being discouraged from the standpoint of environmental protection and ensuring safety for human health. Therefore, metal complex dyes that possess the desirable properties of metal complex dyes but do not contain harmful heavy metals such as chromium are being investigated.

[0007] As one such study, Patent Document 2 discloses a complex mixed dye of three types of disazo compounds and iron as a specific complex-forming agent. Patent Document 3 also discloses a polyazo iron complex dye. However, these iron complex dyes are not black, but exhibit brown or reddish-brown colors. On the other hand, Patent Document 4 discloses a monoazo iron complex salt compound. This monoazo iron complex salt compound exhibits a blackish-purple color and does not reach the level of blackness exhibited by azochrome complex dyes. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 51-023518 [Patent Document 2] Japanese Patent Application Publication No. 5-247360 [Patent Document 3] Special Publication No. 47-044530 [Patent Document 4] Japanese Patent Application Publication No. 63-4992 [Overview of the project] [Problems that the invention aims to solve]

[0009] Conventional ink compositions, such as those described above, which dissolve azo metal complex dyes in ketone-based and / or alcohol-based solvents, have the problem of changing color from black to brown and decreasing blackness when used at high temperatures for extended periods or during long-distance transport.

[0010] The present inventors have diligently studied to solve the above problems, and their objective is to provide an azo metal complex dye that has sufficient solubility in organic solvents for practical use, exhibits good black color, and maintains its blackness without discoloration even when dissolved in ketone-based and / or alcohol-based solvents and stored at high temperatures for a long period of time, as well as an ink composition containing the same. [Means for solving the problem]

[0011] The azo metal complex dye of the present invention, which was made to achieve the above objective, [1] Chemical formula (1) below [ka] (In formula (1), R 1 and R 2 R may be the same or different, and is a linear or branched alkyl group having 3 to 10 carbon atoms. 3 R is a cyano group, nitro group, acetyl group, sulfoamide group, or halogen atom. 4 R is a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms. 5 R is singular or plural and is a nitro group, halogen atom, or sulfoamide group, 6 R is singular or plural and is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, a halogen atom, or a nitro group. 7is a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, M is a trivalent metal, and A + is the following chemical formula (2) [Chemical formula] (In formula (2), R 8 ~R 11 may be the same or different and is a linear or branched alkyl group having 1 to 20 carbon atoms, a phenyl group or a benzyl group, and the total number of carbon atoms of these alkyl groups is 10 to 40)), and contains a disazo-monoazo metal complex dye represented by

[0012] [2] The azo metal complex dye of the present invention is the following chemical formula (3) [Chemical formula] (In formula (3), R 5 ~R 7 , M and A + are the same as those in formula (1).), and a monoazo-monoazo metal complex represented by, and / or the following chemical formula (4) [Chemical formula] (In formula (4), R 1 ~R 4 , M and A + are the same as those in formula (1).) may be included.

[0013] [3] Further, in the azo iron complex dye of the present invention represented by chemical formulas (1), (3), and (4), M is at least one selected from iron, chromium, cobalt, manganese, and titanium.

[0014] [4] The ink composition of the present invention contains the azo metal complex dye according to any one of [1] to [3] and an organic solvent.

[0015] [5] The ink composition may be for an inkjet printer. [Advantages of the Invention]

[0016] The azo metal complex dye of the present invention has sufficient solubility in organic solvents for practical use and exhibits good black color. Furthermore, it does not discolor even when dissolved in ketone-based and / or alcohol-based solvents, and does not maintain its black color even when stored at high temperatures for extended periods. An ink composition containing this azo metal complex dye does not discolor even when dissolved in ketone-based and / or alcohol-based solvents and stored at high temperatures for extended periods, and can be used for printing while maintaining its blackness, and can maintain its blackness without discoloration over time. [Brief explanation of the drawing]

[0017] [Figure 1] The UV / Visible absorption spectra of the azo metal complex dye in Example 2, standardized at the maximum absorption wavelength, are shown before and after the test. [Figure 2] The UV / Visible absorption spectra of the azo metal complex dye in Comparative Example 2, standardized at the maximum absorption wavelength, are shown before and after the test. [Modes for carrying out the invention]

[0018] The following describes in detail embodiments for carrying out the present invention, but the scope of the present invention is not limited to these embodiments.

[0019] (Azo metal complex dyes) The azo metal complex dye used in the method of the present invention is the following chemical formula (1) [ka] (In formula (1), R 1 and R 2 R may be the same or different, and is a linear or branched alkyl group having 3 to 10 carbon atoms. 3 R is a cyano group, nitro group, acetyl group, sulfoamide group, or halogen atom. 4 R is a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms. 5 R is singular or plural and is a nitro group, halogen atom, or sulfoamide group,6 R is singular or plural and is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, a halogen atom, or a nitro group. 7 is a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, M is a trivalent metal, and A + This is the chemical formula (2) below [ka] (In formula (2), R 8 ~R 11 The dye comprises a disazo-monoazo metal complex dye represented by (which may be the same or different, and which is a linear or branched alkyl group having 1 to 20 carbon atoms, a phenyl group or a benzyl group, with the total number of carbon atoms of these alkyl groups being 10 to 40).

[0020] As can be seen from the above chemical formula (1), the disazo-monoazo metal complex contained in the azo metal complex dye of the present invention has a structure in which an azo metal complex anion containing a trivalent metal, a disazo dye, and a monoazo dye as an azo ligand in a 1:2 molar ratio is bonded to a quaternary ammonium cation.

[0021] In chemical formula (1), R 1 and R 2These are linear or branched alkyl groups with 3 to 10 carbon atoms. Specifically, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 2,2-dimethylpentyl group, 2,3-dimethylpentyl group, 2,4-dimethylpentyl group, 3,3-dimethylpentyl group, 3-ethylpentyl group, 2,2,3-trimethylbutyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl Examples of these groups include 4-methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 2-methyl-3-ethylpentyl group, 3-methyl-3-ethylpentyl group, and 2,2,3,3-tetramethylbutyl group, n-nonyl group, n-decyl group, and lauryl group. Among these, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, and 2-ethylhexyl group are preferred.

[0022] In chemical formula (1), R 3 R is an electron-withdrawing group, specifically a cyano group, nitro group, acetyl group, sulfoamide group, and halogen atom. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. 3 When these are electron-withdrawing groups, the color-deepening effect of the azo metal complex dye is enhanced, resulting in a jet-black color. 3 It is preferable in terms of deepening the color if the compound is bonded to the azo group on the same aromatic ring at the para position.

[0023] In chemical formula (1), R 4This group is a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms. Specifically, examples of this alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, and neopentyl groups, and examples of this alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentyloxy, isopentyloxy, and neopentyloxy groups.

[0024] In chemical formula (1), R 5 R is an electron-withdrawing substituent such as a nitro group, a sulfoamide group, or a halogen atom. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. 5 It is preferable that the azo group is bonded to the 4th or 5th position relative to the azo group on the aromatic ring to which it is bonded, as this further improves the blackness of the disazo-monoazo metal complex and allows for a jet-black color to be obtained.

[0025] In chemical formula (1), R 6The group consists of a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, a nitro group, or a halogen atom. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, and n-octyl groups. Examples of halogen atoms include 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 2-methyl-3-ethylpentyl group, 3-methyl-3-ethylpentyl group, and 2,2,3,3-tetramethylbutyl group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0026] In chemical formula (1), R 7The alkyl group is a hydrogen atom or a linear or branched alkyl group having 3 to 12 carbon atoms. Examples of this alkyl group include n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 2,2-dimethylpentyl group, 2,3-dimethylpentyl group, 2,4-dimethylpentyl group, 3,3-dimethylpentyl group, 3-ethylpentyl group, 2,2,3-trimethylbutyl group, n-octyl group, tert-octyl group, 2-methylheptyl group, 3 Examples include -methylheptyl group, 4-methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 2-methyl-3-ethylpentyl group, 3-methyl-3-ethylpentyl group, and 2,2,3,3-tetramethylbutyl group, n-nonyl group, n-decyl group, lauryl group, and dodecyl group. Among these, tert-butyl group, isopentyl group, hexyl group, n-octyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, and dodecyl group are preferred.

[0027] In chemical formula (2), R 8 ~R 11The alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 2,2-dimethylpentyl group, 2,3-dimethylpentyl group, 2,4-dimethylpentyl group, 3,3-dimethylpentyl group, 3-ethylpentyl group, 2,2,3-trimethylbutyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4 Examples include methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 2-methyl-3-ethylpentyl group, 3-methyl-3-ethylpentyl group, and 2,2,3,3-tetramethylbutyl group, n-nonyl group, n-decyl group, undecyl group, lauryl group, cetyl group, and stearyl group. Benzyl groups and phenyl groups may also be used, and these may further have substituents.

[0028] In chemical formula (2), R 8 ~R 11 The total number of carbon atoms in the alkyl group is between 10 and 40. This range does not include benzyl or phenyl groups. By limiting the total number of carbon atoms in the alkyl group to this range, it is possible to achieve both high solubility in organic solvents and excellent thermal stability over time. The details are not entirely clear, but A + However, R 8 ~R 11By using a quaternary ammonium cation, the ionic properties and steric hindrance of the molecule are increased, and the hydrophobicity is also improved due to the large number of carbon atoms in the alkyl group. As a result, it is presumed that the ammonium component is more likely to be present near the metal complex, thus preventing or suppressing the interaction and attack of the azo metal complex anion by impurities, such as oxides (e.g., carboxylic acids) derived from ketone-based or alcohol-based solvents.

[0029] Furthermore, the azo metal complex dye of the present invention has the following chemical formula (3) [ka] (In formula (3), R 5 ~R 7 , M and A + This is the same as formula (1). A monoazo-monoazo metal complex represented by ) and / or the following chemical formula (4) [ka] (In formula (4), R 1 ~R 4 , M and A + This is identical to formula (1). It may further contain a disazo-disazo metal complex represented by ).

[0030] Disazo-monoazo metal complexes are dialkylamino groups having a predetermined number of carbon atoms (-NR in chemical formula (1)). 1 R 2 ) and electron-withdrawing groups (same -R 3 A disazo dye having an electron-withdrawing group (same -R) 5 and / or -R 6 Due to its asymmetrical structure containing a monoazo dye, it deepens in color and absorbs wavelengths in the visible light range. Therefore, ink compositions containing this azo metal complex as a coloring agent exhibit a sufficiently deep black color for practical use.

[0031] Furthermore, if the coloring agent contains a monoazo-monoazo metal complex represented by chemical formula (3) and / or a disazo-disazo metal complex represented by chemical formula (4) in addition to the disazo-monoazo metal complex, the blackness, solubility, and solubility stability of the coloring agent can be appropriately and arbitrarily adjusted by setting the molar ratio of the disazo-monoazo metal complex, monoazo-monoazo metal complex, and disazo-disazo metal complex in the coloring agent to an appropriate range.

[0032] These molar ratios can be expressed as the peak area ratio in the chromatogram obtained when measured by high-performance liquid chromatography at a specific wavelength, for example, 254 nm. Specifically, the ratio of disazo-monoazo metal complex:monoazo-monoazo metal complex:disazo-disazo metal complex is preferably 20-70:5-80:0-50, more preferably 20-65:5-80:0-50, and even more preferably 20-55:20-80:0-15.

[0033] Furthermore, in chemical formulas (1), (3), and (4), M is at least one selected from iron, chromium, cobalt, manganese, and titanium, with iron being the most preferred.

[0034] By using iron as the central metal, it is possible to maintain high solubility and blackness in solvents while simultaneously reducing toxicity, thus ensuring environmental protection and safety for human health.

[0035] To obtain an azo metal complex dye containing an azo metal complex represented by chemical formulas (1), (3), and (4), it is preferable to employ a manufacturing method having the following steps 1 to 5. Step 1: Step to obtain a disazo dye using a diazo coupling reaction. Step 2: Step to obtain a monoazo dye using a diazo coupling reaction. Step 3: Metal complex formation of the disazo dye and monoazo dye mixture Process for obtaining azo metal complex dyes Step 4: Process for changing and adjusting the cations of the azo metal complex dye. Step 5: The process of filtering, washing, drying, and grinding the azo metal complex dye. This manufacturing method allows for the production of high-purity azo metal complex dyes. The following describes each step in detail.

[0036] The first step is to obtain the disazo dye that can act as a disazo ligand in an azo metal complex.

[0037] (1-1: Synthesis of monoazo compounds) First, as shown in the chemical formula (5) below, a specific aromatic amine is diazotized by a known method, and then a diazo coupling reaction is carried out with 2-aminophenol by a conventional method to obtain a monoazo compound, which is an intermediate for disazo dyes. [ka] (In chemical formula (5), R 3 and R 4 This is identical to chemical formula (1).

[0038] In the reaction of chemical equation (5), specifically, an aqueous solution prepared by diluting an aniline derivative having an electron-withdrawing group with hydrochloric acid and sodium nitrite (for example, a 40% by mass prepared aqueous solution) are added to deionized water or a deionized water-lower alcohol mixed solvent, and the mixture is stirred at a temperature of 0 to 5°C for 1 to 3 hours to diazotize the aniline derivative and obtain a diazotized solution. Excess nitrite is decomposed with sulfamic acid or the like.

[0039] Next, an unsubstituted or alkyl or alkoxy group-containing 2-aminophenol derivative is dissolved or finely dispersed in an aqueous solution diluted with hydrochloric acid. The diazotization solution is then added dropwise to the solution, and a diazo coupling reaction is carried out in a hydrophilic solvent or a water-lower alcohol solvent at room temperature or low temperature for several hours while stirring to obtain a solution containing the monoazo compound. The monoazo compound is filtered and washed with water to obtain a wet cake of the monoazo compound. In the next step, the synthesis of the disazo dye, this wet cake may be used after drying, as a wet cake, or as a monoazo compound-containing solution.

[0040] (1-2: Synthesis of disazo dyes) The monoazo compound obtained in the above synthesis is diazotized by a known method as shown in the chemical reaction formula (6) below, and a diazo coupling reaction is carried out with a phenol derivative having a specific dialkylamino group by a conventional method to obtain a solution containing a disazo dye. [ka] (In formula (6), R 1 ~R 4 This is identical to chemical formula (1).

[0041] In the reaction of chemical equation (6), specifically, an aqueous solution prepared by diluting the monoazo compound obtained in the synthesis of 1-1 with hydrochloric acid, and sodium nitrite (for example, a 40% by mass prepared aqueous solution) are added to deionized water or a deionized water-lower alcohol mixed solvent, and the mixture is stirred at a temperature of 0-5°C for 1-3 hours to diazotize the monoazo compound and obtain a diazotized solution. Excess nitrite is decomposed with sulfamic acid or the like.

[0042] Next, the phenol derivative having a dialkylamino group is dissolved or finely dispersed in an alkaline aqueous solution, and the diazotization solution is added dropwise to the solution. The diazo coupling reaction is carried out in a hydrophilic solvent or a water-lower alcohol solvent at room temperature or low temperature for several hours while stirring to obtain a solution containing a disazo dye. The disazo dye is filtered and washed with water to obtain a wet cake of the disazo dye. In the subsequent metal complexing step, this wet cake may be used after drying, as a wet cake, or as a disazo dye-containing solution.

[0043] The second step is to obtain the monoazo dye that can act as a monoazo ligand in the azo metal complex.

[0044] First, a diazotized solution is obtained by diazotizing the 2-aminophenol derivative using a known method. Specifically, an aqueous solution prepared by diluting a 2-aminophenol derivative having an electron-withdrawing substituent and a hydrogen atom or alkyl group with hydrochloric acid is added to deionized water or a deionized water-lower alcohol mixed solvent with sodium nitrite (e.g., a 40% by mass prepared aqueous solution), and the mixture is stirred at a temperature of 0-5°C for 1-3 hours to diazotize the 2-aminophenol derivative and obtain a diazotized solution. Excess nitrite is decomposed with sulfamic acid or the like.

[0045] Next, as shown in the chemical reaction equation (7) below, the diazo compound in the diazotized solution obtained as described above is subjected to a diazo coupling reaction with a 2-naphthol derivative having a hydrogen atom or an alkyl group by a conventional method to obtain a monoazo dye. [ka] (In formula (7), R 5 ~R 7 This is identical to chemical formula (1).

[0046] The reaction of chemical equation (7) is carried out specifically as follows: 2-naphthol is dissolved or finely dispersed in an alkaline aqueous solution, the diazotization solution is added dropwise to the solution, and the diazotization coupling reaction is carried out in a hydrophilic solvent or a water-lower alcohol solvent at room temperature or low temperature for several hours while stirring to obtain a solution containing the monoazo dye. The monoazo dye is filtered and washed with water to obtain a wet cake of the monoazo dye. In the next step, the iron complexization step, this wet cake may be used after drying, as a wet cake, or as a monoazo dye-containing solution.

[0047] The third step involves a metal complexing reaction between the disazo dye and monoazo dye obtained in the previous step and a metallizing agent, thereby producing an azo metal complex X + This is a metal complex formation process that yields an anionic compound.

[0048] The disazo dye obtained in the first step and the monoazo dye obtained in the second step are charged in a predetermined molar ratio and mixed to obtain a mixed dye. This mixed dye is dispersed or dissolved in a solvent, and a predetermined equivalent amount of metallizing agent is added to the mixed dye, and the mixture is heated and stirred at 80 to 140°C for 1 to 5 hours. As a result, X is formed in the disazo-monoazo iron complex, monoazo-monoazo metal complex, and disazo-disazo metal complex as shown in the chemical reaction equation (8) below. + A mixture of anionic compounds is obtained.

[0049] [ka]

[0050] (In formula (8), R 1 ~R 7 This is identical to chemical formula (1), and X + (This refers to any cation, such as a hydrogen ion derived from an acid or alkali, an alkali metal ion, or an alkaline earth metal.)

[0051] The mixing ratio of disazo dye to monoazo dye is preferably 2:8 to 8:2 in molar ratio, with specific examples including mixing ratios of 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, and 8:2. Among these, a ratio of disazo dye to monoazo dye of 2:8 to 5:5 is preferred because it exhibits high blackness and high solubility in the solvent contained in the ink composition.

[0052] Examples of metallurgical agents used in the metal complex formation process include ironizing agents such as ferric sulfate, ferrous sulfate, ferric chloride, ferrous chloride, ferric nitrate, iron acetate, and iron lactate; chromizing agents such as chromium chloride, chromium sulfate, chromium lactate, chromium acetate, and chromium formate; cobaltizing agents such as cobalt chloride, cobalt sulfate, cobalt oxalate, cobalt acetate, and cobalt tartrate; manganeseizing agents such as manganese chloride, manganese sulfate, manganese nitrate, and manganese acetate; and titaniumizing agents such as titanium trichloride, triethoxytitanium, triisopropoxytitanium, and tributoxytitanium. The amount of metallizing agent is preferably 1 / 2 to 2, and more preferably 1 / 2 to 2 / 3, of the total equivalent amount of disazo dye and monoazo dye.

[0053] Examples of solvents used in the metal complex formation process include water, a water-organic solvent mixture, and an organic solvent, with a water-organic solvent mixture being preferred. Examples of organic solvents include alcohol-based solvents, glycol-based solvents, amide-based solvents, ether-based solvents, ketone-based solvents, sulfoxide-based solvents, and aromatic hydrocarbon-based solvents, with alcohol-based solvents, glycol-based solvents, amide-based solvents, and sulfoxide-based solvents being preferred.

[0054] Preferred organic solvents include, specifically, alcoholic solvents such as ethanol, n-propanol, isopropanol, n-butanol, isobutanol, amyl alcohol, benzyl alcohol, cyclohexanol, and diacetone alcohol; alkyl ethers of glycols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and dipropylene glycol monoethyl ether; acetates of glycols such as ethylene glycol monoacetate and propylene glycol monoacetate; glycol-based solvents such as ethylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, and butanediol; and amide-based solvents such as N-methylformamide, N,N-dimethylformamide, N-ethylformamide, N,N-diethylformamide, N-methylacetamide, and N,N-dimethylacetamide. Examples of sulfoxide solvents include sulfolane, 3-methylsulfolane, and dimethyl sulfoxide. Among these, amide solvents are preferred.

[0055] In this third step, an example is shown in which the disazo dye obtained in the first step and the monoazo dye obtained in the second step are mixed before the metallization reaction. However, the third step is not limited to this. Alternatively, the disazo dye or monoazo dye may be added to the solvent, followed by the sequential addition of monoazo dyes or disazo dyes, and then an iron-fixing agent may be added to carry out a metallization reaction with trivalent iron. Alternatively, the disazo dye or monoazo dye may be added to the solvent, followed by the addition of a metallizing agent to carry out a metallization reaction, and then the monoazo dye or disazo dye may be added, with an additional metallizing agent added as needed to carry out a metallization reaction with a trivalent metal. In this case, the excess azo dye that has undergone the metallization reaction first and the other azo dye added later will form a metal complex through the metallization reaction.

[0056] Furthermore, only one type of disazo dye and one type of monoazo dye may be used, or multiple types with different substituents or different substituent attachment positions may be mixed and used. For example, one type of disazo dye may be mixed with two types of monoazo dyes, or two types of disazo dyes may be mixed with one type of monoazo ligand.

[0057] In the metal complex formation process, it is preferable to carry out the process while heating (including reflux stirring) at a temperature suitable for the type of solvent used. Additives such as reaction accelerators and pH adjusters may also be used.

[0058] The fourth step, which involves modifying and adjusting the cations of the azo metal complex, is an ion exchange step in which a quaternary ammonium agent is used to replace any cations of the azo metal complex obtained in the third step with quaternary ammonium ions.

[0059] This cation exchange reaction yields an azo metal complex into which a quaternary ammonium ion, for example represented by chemical formula (2), has been introduced, as shown in the chemical reaction equation (9) below. [ka]

[0060] (In formula (9), R 1 ~R7 This is identical to chemical formula (1), and R 8 ~R 11 This is identical to chemical formula (2), and X + (where is any cation.)

[0061] Examples of quaternary ammonium compounds include the following formula (10): [ka] (In formula (10), R 8 ~R 11 This is identical to chemical formula (2), and Y - is any anion. ) is represented as follows. A single quaternary ammonium agent may be used, or a mixture of multiple agents may be used.

[0062] By combining various conditions such as the amounts of acid, base, and quaternary ammonium agent used for cation exchange and the reaction temperature, azo metal complexes having mixed ions as cations can be obtained. Azo metal complexes can be obtained in which 86 mol% or more, and especially 90 mol% or more, of the cations in the mixed ions are desired quaternary ammonium ions.

[0063] The cation exchange reaction in this fourth step can be carried out simultaneously or sequentially with the metal complexation reaction in the third step using the same reaction system. Alternatively, the fourth step may be carried out by adding a quaternary ammonium agent together with an organic solvent when preparing the ink composition.

[0064] The fifth step is performed as needed after the fourth step and may optionally include a filtration step, a washing step, a drying step, and a grinding step.

[0065] A filtration step may be performed. The filtration step is a step in which the reaction solution containing the azo metal complex obtained in step 4 is separated into a solid of the azo metal complex and a solvent by filtration to obtain a wet cake of the azo metal complex. Examples of filtration methods include heavy pressure filtration methods such as filter paper filtration, bag filtration, and centrifugation; vacuum filtration methods using filters such as Nutsche, Moore filters, disc filters, drum filters, and Oliver filters; and pressurized filtration methods such as filter presses, closed leaf filters, and closed multi-stage filters.

[0066] If necessary, a washing step may be performed after the filtration step. The azo metal complex wet cake is thoroughly washed with a washing solution. Examples of washing solutions include water and organic solvents, with water being preferred. This wet cake may be used as an intermediate in the next step.

[0067] If necessary, a drying step may be performed after the washing step to dry the wet cake of the azo metal complex. The dried, lumpy azo metal complex is then crushed or pulverized using a known pulverizer to achieve the desired particle size.

[0068] In the azo iron complex dyes of the present invention, the disazo ligand and monoazo ligand, quaternary ammonium cation, and azo metal complex dyes formed by combining these ligands are described below.

[0069] (Disazo ligand) The disazo ligand (D ligand), which is the ligand for the azo metal complex dye of the present invention, is specifically represented by the following chemical formula (11). [ka] (In chemical formula (11), R 1 and R 2 This is identical to chemical formula (1), and R 3a ~R 3cAny one of them is an electron-withdrawing group selected from a cyano group, a nitro group, an acetyl group, a sulfonamide group, and a halogen atom, and the others are hydrogen atoms, and R 4a ~R 4c are all hydrogen atoms or any one of them is a linear or branched alkyl group having 1 to 5 carbon atoms or a linear or branched alkoxy group having 1 to 5 carbon atoms, and the others are hydrogen atoms.)

[0070] In Chemical Formula (11), R 1 , R 2 , R 3a ~R 3c , and R 4a ~R 4c The specific substituents of are shown in Table 1.

[0071]

Table 1

[0072] (Monoazo ligand) The monoazo ligand (M ligand), which is a ligand of the azo metal complex dye of the present invention, is specifically represented by the following Chemical Formula (12).

Chemical formula

[0073] In Chemical Formula (12), R 5a , R 5b , R 6a , R 6b , and R 7a ~R 7f The specific substituents of are shown in Table 2.

[0074]

Table 2

[0075] (Quaternary ammonium cation) The quaternary ammonium cation (Am + ), which is the counter cation of the azo metal complex dye of the present invention, is specifically represented by the following Chemical Formula (l3).

Chemical formula

[0076] In Chemical Formula (13), R 8 , R 9 , R 10 and R 11 The specific substituents of are shown in Table 3.

[0077]

Table 3

[0078] The azo metal complex dye of the present invention comprises at least a disazo-monoazo metal complex (DM compound) having a quaternary ammonium cation having an alkyl group as shown in Table 3, represented by the chemical formula (13), specifically comprising at least one disazo ligand (D ligand) represented by the chemical formula (11) and having substituents shown in Table 1, for example, and at least one monoazo ligand (M ligand) represented by the chemical formula (12) and having substituents shown in Table 2, for example, each of which is coordinated to a metal atom in 1 moles, and specifically comprising a disazo-monoazo metal complex (DM compound) having an alkyl group shown in Table 3, for example, represented by the chemical formula (13).

[0079] In addition to the DM form, azo metal complex dyes may also include a monoazo-monoazo metal complex (MM form) represented by chemical formula (13) having a quaternary ammonium cation having an alkyl group as shown in Table 3, represented by chemical formula (13), in which 2 moles of at least one M ligand shown in Table 2 coordinate to a metal atom, and a disazo-disazo metal complex (DD form) represented by chemical formula (13) having a quaternary ammonium cation having an alkyl group as shown in Table 3, represented by chemical formula (12) having 2 moles of at least one D ligand having a substituent shown in Table 1 coordinate to a metal atom. The ratio of each azo metal complex species in such azo metal complex dyes, the D ligand species and M ligand species they possess, the quaternary ammonium cation, the central metal species, and the mixing ratio of disazo dye (D dye) and monoazo dye (M dye) to obtain each azo iron complex dye are shown in Table 4. In Table 4, the symbols in the D ligand, M ligand, and quaternary ammonium cation columns correspond to the descriptions in Tables 1, 2, and 3.

[0080] [Table 4]

[0081] (Method for evaluating thermal stability over time) As a method for evaluating thermal stability over time, for example, the above-mentioned azo metal complex dye is dissolved in a ketone-based solvent, and the solution is left to stand in a 50°C constant temperature bath for 4 weeks. The ultraviolet / visible light absorption spectra of the solution after 4 weeks and the solution before the test are measured and normalized by the maximum absorption wavelength. The absorbance at the wavelength with the greatest change in the spectrum normalized by the maximum absorption wavelength can be read, and the attenuation rate can be calculated and evaluated.

[0082] (Ink composition for inkjet printers) The azo metal complex dye of the present invention is particularly preferred as a colorant for inkjet printer ink compositions.

[0083] An inkjet printer ink composition using the azo metal complex dye of the present invention contains the above-mentioned azo metal complex dye and a solvent, and may further contain a resin.

[0084] The solvent for the inkjet printer ink composition using the azo metal complex dye of the present invention is a ketone-based and / or alcohol-based solvent.

[0085] Examples of ketone-based solvents include lower alkyl ketones such as acetone, methyl ethyl ketone, dipropyl ketone, methyl isobutyl ketone, and methyl isopropyl ketone; and cyclic ketones such as cyclohexanone. Among these, methyl ethyl ketone and methyl isopropyl ketone are suitable for ink compositions because they have good resin solubility, pigment dispersibility, and ink drying properties.

[0086] Examples of alcohol-based solvents include methanol, ethanol, propanol, and lower alkyl alcohols such as isopropanol and butanol; and glycols such as dioxane, ethylene glycol, diethylene glycol, and triethylene glycol.

[0087] Other organic solvents include ester-based organic solvents such as ethyl acetate, ethyl propionate, ethyl lactate, propyl acetate, and butyl acetate; and aromatic hydrocarbon-based organic solvents such as toluene and xylene.

[0088] The above organic solvents may be used individually or in combination.

[0089] Examples of resins include cellulose resins, styrene-acrylic resins, terpene phenol resins, polyvinyl butyral resins, ketone resins, maleic acid resins, rosin resins, acrylic resins, styrene-maleic acid resins, polyvinyl acetal resins, polyvinyl alcohol resins, rosin ester resins, silicone resins, phenolic resins, coumarone indene resins, novolac resins, aldehyde resins, polyester resins, polyamide resins, polyimide resins, terpene resins, alkyd resins, urethane resins, acetal resins, epoxy resins, urea resins, melamine resins, and xylene resins. These resins may be used individually or in combination.

[0090] Specific examples of the above-mentioned cellulosic resins include nitrocellulose; lower acyl group substituted derivatives such as cellulose propionate, cellulose butyrate, cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate; lower alkyl group substituted derivatives such as methylcellulose and ethylcellulose; cellulose nitrate; and hydroxypropylcellulose.

[0091] These cellulose resins come in a variety of types depending on the degree of hydroxyl group substitution and molecular weight. The cellulose resin is appropriately selected according to the viscosity required for the ink composition. For example, cellulose esters are those in which the hydroxyl groups of the cellulose resin are modified in whole or in part by one or more types of esters having 2 to 8 carbon atoms, preferably 2 to 5 carbon atoms. Specifically, lower acyl group-substituted derivatives of cellulose, such as cellulose acetate propionate and cellulose acetate butyrate, are preferred. For cellulose acetate butyrate, those with a degree of substitution of acetyl groups of 2 to 20% and 32 to 53% of butyryl groups, respectively, are particularly preferred. Similarly, for cellulose acetate propionate, those with a degree of substitution of acetyl groups of 0.5 to 10% and 35 to 55% of propionyl groups, respectively, are particularly preferred. The degree of substitution is defined as 100% when all three hydroxyl groups of one glucose unit are substituted.

[0092] Styrene-acrylic resin is a copolymer of a styrene monomer and an acrylic monomer, preferably having an acid value of 120 or less and a molecular weight of 3,000 to 30,000. Examples of styrene monomers include styrene, α-methylstyrene, and vinyltoluene. Examples of acrylic monomers include acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, butyl methacrylate, amyl acrylate, amyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate.

[0093] Styrene-acrylic resins are available on the market, including, for example, Joncryl® 68, 586, and 611 (manufactured by BASF), Hymer® SBM-100 and Hymer SAM-955 (manufactured by Sanyo Chemical Industries), and Nikalite® NC-6531 and Nikalite NC-6100 (manufactured by Nippon Carbide Co., Ltd.).

[0094] Terpene phenol resins are copolymers of terpenes such as α-pinene, β-pinene, and dipentene with phenols such as phenol and bisphenol. Monomers are selected according to the requirements of the ink composition, and the molar ratio of each monomer is set. Terpene phenol resins are available on the market, and examples include YP90 and YP90L; YS Polystar S145, #2100, #2115, #2130, T80, T100, T115, T130, and T145; Mighty Ace G125 and G150 (all manufactured by Yasuhara Chemical Co., Ltd.).

[0095] Polyvinyl butyral resin is a copolymer of polyvinyl alcohol and butyraldehyde. The degree of butyralization, the content of hydroxyl and acetyl groups, and the degree of polymerization are set according to the requirements of the ink composition. From the viewpoint of the viscosity of the ink composition and solubility in solvents, it is preferable that the polyvinyl butyral resin has a relatively low degree of polymerization. Polyvinyl butyral resins are available on the market, including, for example, S-REC® BL-1, BL-2, BL-3, BL-S, BM-1, BM-2, BM-5, BM-S, BH-3, BH-S, BX-1, BX-2, BX-5, BX-10, BX-55, and BX-L (manufactured by Sekisui Chemical Co., Ltd.); and Denka Butyral #2000-L, #3000-1, #3000-2, #3000-4, #3000-K, #4000-1, #4000-2, #5000-A, and #6000-C (manufactured by Denka Co., Ltd.).

[0096] The ketone resin is preferably a polymer compound that is a copolymer of a ketone compound and formaldehyde, with an average molecular weight of 3000 or more. The ketone resin may be chemically modified, such as by hydrogenation and / or end-group modification. Ketone resins are available on the market, and examples include Hi-Lac® 111 and 222 (manufactured by Showa Denko Materials Co., Ltd.); and K-90 (manufactured by Arakawa Chemical Industries, Ltd.).

[0097] The maleic acid resin is preferably a rosin-modified maleic acid resin. A rosin-modified maleic acid resin is a polyester of rosin, maleic acid, and a polyhydric alcohol. Rosin-modified maleic acid resins are available on the market, and examples include Beccasite® P-720 and J-896 (manufactured by DIC Corporation); and Tespol® 1101, 1103, 1104, 1105, 1150, 1151, 1152, 1155, 1158, and 1161 (manufactured by Showa Denko Materials Co., Ltd.).

[0098] The inkjet printer ink composition containing the azo metal complex dye of the present invention may further contain a wetting agent. Examples of wetting agents include surfactants, specifically anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants.

[0099] Examples of anionic surfactants include fatty acid salts, alkyl sulfate salts, alkylaryl sulfonates, alkylnaphthalene sulfonates, dialkyl sulfonates, dialkyl sulfosuccinates, alkyldiaryl ether disulfonates, alkyl phosphates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylaryl ether sulfates, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl phosphate salts, glycerol borate fatty acid esters, and polyoxyethylene glycerol fatty acid esters.

[0100] Examples of cationic surfactants include alkylamine salts, quaternary ammonium salts, alkylpyridinium salts, and alkylimidazolium salts.

[0101] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, fluorine-based nonionic surfactants, and silicone-based nonionic surfactants.

[0102] Examples of amphoteric surfactants include alkyl betaine, alkylamine oxide, and phosphatidylcholine.

[0103] The ink composition of the present invention may contain a pH adjuster to suppress changes in ink composition such as precipitation and sedimentation of dyes, and a decrease in storage stability such as discoloration. The pH adjuster is not particularly limited as long as it is added for the above purpose and can control the pH of the ink in the range of 7 to 8.

[0104] Specifically, examples of pH adjusters include aliphatic substituted amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, and tripropylamine, as well as alkanolamines such as methanolamine, dimethanolamine, trimethanolamine, ethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine, and tripropanolamine. Alkanolamines such as triethanolamine are particularly preferred from the viewpoint of suppressing discoloration.

[0105] Inkjet printer ink compositions may contain, in addition to or instead of, wetting agents to improve print quality, ink fixation, and the solubility stability of azo metal complex dyes, and to impart desired viscosity and surface tension. Examples of such additives include defoamers, chemical stabilizers, UV stabilizers, and stabilizers that inhibit corrosion by salts; biosides such as fungicides and antifungal agents; and pH adjusters.

[0106] A method for manufacturing an inkjet printer ink composition is described below. Azo metal complex dye, organic solvent, resin, and optionally additives are placed in a sealed container and stirred. These are then mixed and dissolved uniformly, and the mixture is filtered through a membrane filter. The mixed solution may be heated if necessary.

[0107] Inkjet printer ink compositions can be used not only in small printers for office and home use, but also in large industrial printers such as continuous inkjet printers and thermal jet inkjet printers.

[0108] Furthermore, the azo metal complex dye of the present invention can also be used as a colorant for ink compositions for writing instruments. When the ink composition is used as ink for writing instruments, specifically as ink for marking pens, the content of the azo metal complex dye is 5 to 10% by mass, and when it is used as ink for ballpoint pens, it is 15 to 25% by mass. [Examples]

[0109] The following describes in detail examples to which the present invention is applied and comparative examples to which the present invention is not applied. In the examples, "%" means "mass%".

[0110] (Synthesis Example 1) (Synthesis Example 1-1: Synthesis of disazo dye D-1) 118.0 g (1.0 mol) of p-aminobenzonitrile and 339 g of 35% hydrochloric acid were added to 592.0 g of deionized water, cooled to -3°C under an ice bath, and 178 g of 40% sodium nitrite aqueous solution was gradually added to carry out the diazotization reaction to obtain a diazonium salt solution.

[0111] In a separate beaker, 123.0 g (1.0 mol) of 2-amino-p-cresol and 104.0 g of 35% hydrochloric acid were added to 412 g of deionized water and dissolved. 4 g of 1-butanol and 140 g of ice were added to this mixture and cooled to 2°C. The previously prepared diazonium salt solution was then gradually added dropwise. The pH was adjusted to 4.9 with a 20% sodium hydroxide aqueous solution, and the precipitate was filtered under reduced pressure. After washing with deionized water, 664 g of a wet cake of the monoazo compound represented by the following chemical formula (14) was obtained.

[0112] [ka]

[0113] 304 g (0.42 mol) of the previously obtained monoazo compound wet cake was added to 402 g of deionized water and dispersed by stirring. 49 g of 48% potassium hydroxide aqueous solution was gradually added. After stirring for 30 minutes, 126 g of deionized water and 84 g of ice were added, and stirring was continued for another 30 minutes. After stirring, 75 g of 40% sodium nitrite aqueous solution was added and stirred for 5 minutes. Next, 153 g of 35% hydrochloric acid was added dropwise using a dropping funnel. After dropwise addition, the mixture was stirred for about 1 hour to obtain the diazonium salt solution.

[0114] In a separate beaker, 88 g (0.40 mol) of N,N-dibutyl-3-aminophenol and 133 g of 48% potassium hydroxide aqueous solution were added to 1332 g of methanol and stirred under ice cooling to dissolve. The previously obtained diazonium salt solution was then added dropwise and stirred for 12 hours. The precipitate was filtered under reduced pressure and washed with deionized water to obtain 409 g of wet cake. This was dried at 80°C to obtain 163.6 g of disazo dye D-1, represented by the following chemical formula (15).

[0115] [ka]

[0116] (Synthesis Example 1-2: Synthesis of Monoazo Dye M-1) 7.5 g (0.05 mol) of 4-nitro-2-aminophenol and 13.6 g of 35% hydrochloric acid were dissolved in 50.0 g of isopropanol, and 8.0 g of 40% sodium nitrite aqueous solution was gradually added under an ice bath to diazotize and obtain a diazonium salt solution.

[0117] In a separate beaker, 200 g of water was placed, 26.1 g of 20% sodium hydroxide aqueous solution was added, and then 6.6 g of 2-naphthol was added and dispersed. The previously prepared diazonium salt was added dropwise to this dispersion and the mixture was allowed to react for 3 hours. After that, the pH was adjusted to 2.8, and the precipitated monoazo compound was filtered and washed with water to obtain 82.5 g of a wet cake of monoazo dye M-1 represented by the following chemical formula (16).

[0118] [ka]

[0119] (Synthesis Examples 1-3: Synthesis of Azo Complex Salt Dye 1) 5.3 g (0.011 mol) of the wet cake of disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (40% water content, 0.043 mol) of the wet cake of monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 2:8 mol). Then, 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature. 9.0 g of a 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 15.1 g of quaternary ammonium salt (manufactured by Toho Chemical Industry Co., Ltd.; trade name: Catinal LTC, 15 carbon atoms) was gradually added to the reaction mixture, and the mixture was heated and stirred at 40°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 18.2 g of azo complex dye 1 containing a disazo-monoazo iron complex represented by the following chemical formula (17), a monoazo-monoazo iron complex represented by the following chemical formula (18), and a disazo-disazo iron complex represented by the following chemical formula (19).

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] (Confirmation of the composition of azo complex salt dyes) For the azo complex salt dye 1 obtained in Synthesis Example 1-3, a solution prepared by dissolving 1 mg of azo complex salt dye 1 in 10 ml of dimethylformamide was used as the measurement sample. High-performance liquid chromatography analysis was performed under the measurement conditions shown below, and the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (17), the monoazo-monoazo iron complex represented by chemical formula (18), and the disazo-disazo iron complex represented by chemical formula (19) contained in azo complex salt dye 1 was determined from the area ratio of the peaks in the obtained chromatogram. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (17):monoazo-monoazo iron complex represented by chemical formula (18):disazo-disazo iron complex represented by chemical formula (19) was 26:73:1. [Measurement conditions] High-performance liquid chromatography analyzer: Prominence (manufactured by Shimadzu Corporation) Column: L-Column2 ODS (Length 250mm x Inner diameter 4.6mm, particle size 5μm; manufactured by the Chemicals Evaluation and Research Institute) Column temperature: 40℃ Mobile phase: Solution A: Tetrahydrofuran (HPLC grade, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) / Acetonitrile (manufactured by the same company) = 3 / 2 (volume / volume) Solution B: Ultrapure water / 10 mM tetraethylammonium aqueous solution (Waters Co., Ltd.) = 500 / 7.5 (volume / volume) Gradient: Solution A / Solution B 50:50 → 70:30 (volume / volume) Detector: PDA (Photo Diode Array) Measurement wavelength: 254nm (ultraviolet)

[0124] (Synthesis Example 2) (Synthesis Example 2-1) 5.3 g (0.011 mol) of the wet cake of disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (40% water content, 0.043 mol) of the wet cake of monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 2:8 mol). Then, 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature. 9.0 g of a 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 9.1 g of quaternary ammonium salt (manufactured by Toho Chemical Industry Co., Ltd.; trade name: Catinal CTC, 19 carbon atoms) was gradually added to the reaction mixture, and the mixture was heated and stirred at 40°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 19.4 g of azo complex dye 2 containing a disazo-monoazo iron complex represented by the following chemical formula (20), a monoazo-monoazo iron complex represented by the following chemical formula (21), and a disazo-disazo iron complex represented by the following chemical formula (22).

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] For the azo complex dye 2 obtained in Synthesis Example 2-1, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (20), the monoazo-monoazo iron complex represented by chemical formula (21), and the disazo-disazo iron complex represented by chemical formula (22) contained in the azo complex dye 2 was determined in the same manner as in Synthesis Example 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (20): monoazo-monoazo iron complex represented by chemical formula (21): disazo-disazo iron complex represented by chemical formula (22) was 31:68:1.

[0129] (Synthesis Example 3) (Synthesis Example 3-1) 5.3 g (0.011 mol) of the wet cake of disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (40% water content, 0.043 mol) of the wet cake of monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 2:8 mol). Then, 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature. 9.0 g of a 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 6.45 g of a quaternary ammonium salt (tetrabutylammonium bromide, 16 carbon atoms) was gradually added to the reaction mixture, and the mixture was heated and stirred at 40°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 17.3 g of azo complex dye 3 containing a disazo-monoazo iron complex represented by the following chemical formula (23), a monoazo-monoazo iron complex represented by the following chemical formula (24), and a disazo-disazo iron complex represented by the following chemical formula (25).

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] For the azo complex dye 3 obtained in Synthesis Example 3-1, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (23), the monoazo-monoazo iron complex represented by chemical formula (24), and the disazo-disazo iron complex represented by chemical formula (25) contained in the azo complex dye 3 was determined in the same manner as in Synthesis Example 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (23): monoazo-monoazo iron complex represented by chemical formula (24): disazo-disazo iron complex represented by chemical formula (25) was 32:67:1.

[0134] (Synthesis Example 4) (Synthesis Example 4-1) 5.3 g (0.011 mol) of the wet cake of disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (40% water content, 0.043 mol) of the wet cake of monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 2:8 mol). Then, 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature. 9.0 g of a 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 12.5 g of a quaternary ammonium salt (benzyltributylammonium chloride, C12) was gradually added to the reaction mixture, and the mixture was heated and stirred at 40°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 18.1 g of azo complex dye 4 containing a disazo-monoazo iron complex represented by the following chemical formula (26), a monoazo-monoazo iron complex represented by the following chemical formula (27), and a disazo-disazo iron complex represented by the following chemical formula (28).

[0135] [ka]

[0136] [ka]

[0137] [ka]

[0138] For the azo complex dye 4 obtained in Synthesis Example 4-1, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (26), the monoazo-monoazo iron complex represented by chemical formula (27), and the disazo-disazo iron complex represented by chemical formula (28) contained in the azo complex dye 4 was determined in the same manner as in Synthesis Example 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (26): monoazo-monoazo iron complex represented by chemical formula (27): disazo-disazo iron complex represented by chemical formula (28) was 22:76:2.

[0139] (Synthesis Example 5) (Synthesis Example 5-1) 5.3 g (0.011 mol) of the wet cake of disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (40% water content, 0.043 mol) of the wet cake of monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 2:8 mol). Then, 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature. 9.0 g of a 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 283 g of a quaternary ammonium salt (4.7% aqueous solution of di-n-alkyldimethylammonium chloride, 34-38 carbon atoms) was gradually added to the reaction mixture, and the mixture was heated and stirred at 40°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 29 g of azo complex dye 5 containing a disazo-monoazo iron complex represented by the following chemical formula (29), a monoazo-monoazo iron complex represented by the following chemical formula (30), and a disazo-disazo iron complex represented by the following chemical formula (31).

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] In equations (29), (30), and (31) above, R and R' are nC, respectively. 16 H 33 or nC 18 H 37 That is the case.

[0144] For the azo complex dye 5 obtained in Synthesis Example 5-1, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (29), the monoazo-monoazo iron complex represented by chemical formula (30), and the disazo-disazo iron complex represented by chemical formula (31) contained in the azo complex dye 5 was determined in the same manner as in Synthesis Example 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (29): monoazo-monoazo iron complex represented by chemical formula (30): disazo-disazo iron complex represented by chemical formula (31) was 11:88:1.

[0145] (Synthesis Example 6) (Synthesis Example 6-1: Synthesis of disazo dye D-6) 172 g (1.00 mol) of p-aminobenzenesulfonamide and 271 g of 35% hydrochloric acid were added to 600 g of deionized water and cooled to -3°C in an ice bath. 179.3 g of 40% sodium nitrite aqueous solution was gradually added to this mixture. 2.4 g of urea was then added to carry out the diazotization reaction, obtaining a diazonium salt solution.

[0146] In a separate beaker, 123.4 g (1.00 mol) of 2-amino-p-cresol and 125.0 g of 35% hydrochloric acid were added to 440 g of deionized water and dissolved. 4 g of 1-butanol and 140 g of ice were added, and the mixture was cooled to 2°C in an ice bath. The previously prepared diazonium solution was then gradually added dropwise. The pH was adjusted to 4.8 with a 20% sodium hydroxide aqueous solution, and the precipitate was filtered under reduced pressure. After washing with deionized water, 719.5 g of a wet cake of the monoazo compound represented by the following chemical formula (32) was obtained.

[0147] [ka]

[0148] 700 g (0.90 mol) of the previously obtained monoazo compound wet cake was dispersed in 700 g of deionized water, and then 82.7 g of 48% sodium hydroxide aqueous solution was gradually added, and the mixture was stirred for 1 hour. 700 g of ice was added in an ice bath to cool to 1°C, and then 162.0 g of 40% sodium nitrite aqueous solution was gradually added. After stirring for a while, 300 g of ice was added, and then 287.0 g of 35% hydrochloric acid was gradually added, and the mixture was stirred at room temperature for 2 hours to obtain a diazonium salt solution.

[0149] In a separate beaker, 193.2 g (0.88 mol) of N,N-dibutylaminophenol and 217.5 g of 48% sodium hydroxide aqueous solution were added to 690 g of methanol and stirred under ice cooling to dissolve. The previously obtained diazonium salt solution was then added dropwise and stirred for 12 hours. The pH was adjusted to 4.0 using 35% hydrochloric acid, and the temperature was raised to 35°C and stirred for 1 hour. The precipitate was filtered under reduced pressure and washed with deionized water to obtain 441.1 g of wet cake. This was dried at 80°C to obtain 175.2 g of disazo dye D-2, represented by the following chemical formula (33).

[0150] [ka]

[0151] (Synthesis Example 6-2: Synthesis of Monoazo Dye M-6) 188.2 g (1.00 mol) of 2-aminophenol-4-sulfonamide and 312.5 g of 35% hydrochloric acid were dissolved in 1000 g of deionized water. Under an ice bath, 175.9 g of 40% sodium nitrite aqueous solution was gradually added to diazotize the mixture and obtain a diazonium salt solution.

[0152] In a separate beaker, 1000 g of water was placed, 600 g of 20% sodium hydroxide aqueous solution was added, and then 144.2 g of 2-naphthol was added and dispersed. The previously prepared diazonium salt was added dropwise to this dispersion and the mixture was reacted for 3 hours. After that, the pH was adjusted to 4-5, and the precipitated monoazo compound was filtered and washed with water to obtain a wet cake. This was dried at 80°C to obtain 308 g of the monoazo dye M-6 represented by the following chemical formula (34).

[0153] [ka]

[0154] (Synthesis Example 6-3: Synthesis of Azo Complex Salt Dye 6) 8.4 g (0.016 mol) of disazo dye D-6 obtained in Synthesis Example 6-1 and 32.6 g (40% water content, 0.038 mol) of a wet cake of monoazo dye M-6 obtained in Synthesis Example 6-2 were added to 100 g of water and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 90°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature, and 9.0 g of 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 7.3 g of quaternary ammonium salt (benzyltributylammonium chloride, C12) was gradually added to the reaction mixture and heated and stirred at 40°C for 1 hour. Subsequently, the precipitate was filtered, washed with water, and dried to obtain 21.2 g of azo complex dye 6 containing a disazo-monoazo iron complex represented by the following chemical formula (35), a monoazo-monoazo iron complex represented by the following chemical formula (36), and a disazo-disazo iron complex represented by the following chemical formula (37).

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] For the azo complex dye 6 obtained in Synthesis Example 6-3, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (35), the monoazo-monoazo iron complex represented by chemical formula (36), and the disazo-disazo iron complex represented by chemical formula (37) contained in the azo complex dye 6 was determined in the same manner as in Synthesis Example 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (35): monoazo-monoazo iron complex represented by chemical formula (36): disazo-disazo iron complex represented by chemical formula (37) was 44:51:5.

[0159] (Synthesis Example 7) (Synthesis Example 7-1: Synthesis of Azo Complex Salt Dye 7) 8.2 g (0.015 mol) of disazo dye D-1 obtained in Synthesis Example 1-1, 11.8 g (0.035 mol) of monoazo dye M-6 obtained in Synthesis Example 6-2, and 3.6 g (0.060 mol) of urea were added to 50 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 11.8 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the reaction solution, which had been allowed to cool to 90°C, was poured into a beaker containing 200 g of water. 18.8 g of quaternary ammonium salt (manufactured by Toho Chemical Industry Co., Ltd.; trade name Catinal LTC, 15 carbon atoms) was gradually added and heated and stirred at 35°C for 1 hour. Subsequently, the precipitate was filtered, washed with water, and dried to obtain 24.6 g of azo complex dye 7 containing a disazo-monoazo iron complex represented by the following chemical formula (38), a monoazo-monoazo iron complex represented by the following chemical formula (39), and a disazo-disazo iron complex represented by the following chemical formula (19).

[0160] [ka]

[0161] [ka]

[0162] [Chemical formula]

[0163] (Confirmation of Composition of Azo Complex Dye) Regarding the azo complex dye 7 obtained in Synthesis Example 7-1, in the same manner as in Synthesis Examples 1-3, the relative abundance ratios (molar ratios) of the disazo-monoazo iron complex represented by the above chemical formula (38), the monoazo-monoazo iron complex represented by the above chemical formula (39), and the disazo-disazo iron complex represented by the above chemical formula (19) contained in the azo complex dye 7 were determined. As a result, the molar ratio of the disazo-monoazo iron complex represented by the above chemical formula (38): the monoazo-monoazo iron complex represented by the above chemical formula (39): the disazo-disazo iron complex represented by the above chemical formula (19) was 29:69:2.

[0164] (Synthesis Example 8) (Synthesis Example 8-1: Synthesis of Azo Complex Dye 8) 8.2 g (0.015 mol) of the disazo dye D-6 obtained in Synthesis Example 6-1, 11.8 g (0.035 mol) of the monoazo dye M-6 obtained in Synthesis Example 6-2, and 3.6 g (0.060 mol) of urea were added to a mixed solvent of 50 g of propylene glycol monomethyl ether and 30 g of ethylene glycol, and stirred at 55 °C for 1 hour (disazo dye: monoazo dye = 3:7 mol). Then, 3.8 g (0.013 mol) of chromium formate was added thereto, and the temperature was raised to 103 °C and stirred for 3 hours. After completion of the reaction, the reaction solution cooled to 90 °C was poured into a beaker containing 200 g of water. Then, 18.1 g of a quaternary ammonium salt (manufactured by Toho Chemical Industry Co., Ltd.; trade name Katinal LTC, carbon number 15) was gradually added, and heated and stirred at 45 - 55 °C for 1 hour. Thereafter, the precipitate was filtered, washed with water, and dried to obtain 20.1 g of an azo complex dye 8 containing a disazo-monoazo chromium complex represented by the following chemical formula (40), a monoazo-monoazo chromium complex represented by the following chemical formula (41), and a disazo-disazo chromium complex represented by the following chemical formula (42).

[0165] [Chemical formula]

[0166] [Chemical formula]

[0167] [Chemical formula]

[0168] Regarding the azo complex salt dye 8 obtained in Synthesis Example 8-1, in the same manner as in Synthesis Examples 1-3, the relative abundance ratios (molar ratios) of the disazo-monoazo chromium complex represented by the above chemical formula (40), the monoazo-monoazo chromium complex represented by the above chemical formula (41), and the disazo-disazo chromium complex represented by the above chemical formula (42) contained in the azo complex salt dye 8 were determined. As a result, the molar ratio of the disazo-monoazo chromium complex represented by the above chemical formula (40): the monoazo-monoazo chromium complex represented by the above chemical formula (41): the disazo-disazo chromium complex represented by the above chemical formula (42) was 32:65:3.

[0169] (Thermal aging test) (Example 1) 6 g of the azo complex salt dye 1 obtained in Synthesis Example 1 was added to a 200 ml beaker, and 94 g of methyl ethyl ketone as a solvent was added, followed by stirring with a magnetic stirrer for 1 hour. The solution was filtered using a 1 μm PTFE membrane filter. The obtained solution was placed in a sample bottle and left standing in a thermostat at 50°C for 4 weeks.

[0170] Measurement of ultraviolet / visible light absorption spectrum was performed as follows. 168 mg of the solution containing the azo complex salt dye was taken and placed in a 100 ml volumetric flask, and the solvent was poured up to the calibration line. 5 ml of this solution was taken with a whole pipette and placed in a 50 ml volumetric flask, and the solvent was poured up to the calibration line. This solution was placed in a quartz cell with an optical path length of 1 cm, and the ultraviolet / visible light absorption spectrum was measured with an absorbance measuring instrument (UV-2600i, manufactured by Shimadzu Corporation).

[0171] The ultraviolet / visible light absorption spectra before and after the thermal aging test were normalized at the maximum absorption wavelength, and the attenuation rate at the wavelength showing the largest change was determined to evaluate the thermal aging stability. The results are shown in Table 5. The attenuation rate was calculated using the following formula.

[0172]

number

[0173] To confirm the presence of precipitates, the sample bottles were slowly inverted after the thermal aging test, and the presence or absence of precipitates on the bottom and walls was visually inspected. The results are shown in Table 5.

[0174] (Examples 2-8) The azo complex salt dye and solvent were changed as shown in Table 1, and the thermal stability test was performed in the same manner as in Example 1.

[0175] [Table 5]

[0176] (Comparative Synthesis Example 1) 5.3 g (0.011 mol) of the wet cake dried product of the disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (water content 40%, 0.043 mol) of the wet cake of the monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of an N,N-dimethylformamide solution, and the mixture was stirred at 55 °C for 1 hour (disazo dye:monoazo dye = 2:8 mol). 12.4 g (0.013 mol) of a 41% aqueous ferric sulfate solution was added dropwise thereto, and after completion of the dropwise addition, the temperature was raised to 120 °C and the mixture was stirred for 3 hours. After completion of the reaction, the mixture was allowed to cool to room temperature, 9.0 g of a 20% aqueous sodium hydroxide solution was added thereto to adjust the pH to 10.0, and 103.6 g of a 5% tert-alkyl (C12-C14) primary amine (manufactured by Dow Chemical Company; trade name PRIMENE 81-R) aqueous solution was gradually added to the reaction solution, and the mixture was heated and stirred at 40 °C for 1 hour. Then, the precipitate was filtered, washed with water, and dried to obtain 23.1 g of Comparative azo-based complex salt dye 1 containing a disazo-monoazo iron complex represented by the following chemical formula (43), a monoazo-monoazo iron complex represented by the following chemical formula (44), and a disazo-disazo iron complex represented by the following chemical formula (45).

[0177]

Chem.

[0178]

Chem.

[0179]

Chem.

[0180] (Confirmation of the composition of the azo-based complex salt dye) For the comparative azo complex dye 1 obtained in comparative synthesis example 1, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (43), the monoazo-monoazo iron complex represented by chemical formula (44), and the disazo-disazo iron complex represented by chemical formula (45) contained in comparative azo complex dye 1 was determined in the same manner as in synthesis example 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (43): monoazo-monoazo iron complex represented by chemical formula (44): disazo-disazo iron complex represented by chemical formula (45) was 40:59:1.

[0181] (Comparative Synthesis Example 2) 5.3 g (0.011 mol) of the wet cake of disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (40% water content, 0.043 mol) of the wet cake of monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 2:8 mol). Then, 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature. 9.0 g of a 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 4.6 g of ethoxylated cocoalkylamine (manufactured by NOF Corporation; Naimine L-201), a secondary amine surfactant, was gradually added to the reaction mixture, and the mixture was heated and stirred at 40°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 18.7 g of comparative azo complex dye 2, which contains a disazo-monoazo iron complex represented by the following chemical formula (46), a monoazo-monoazo iron complex represented by the following chemical formula (47), and a disazo-disazo iron complex represented by the following chemical formula (48).

[0182] [ka]

[0183] [ka]

[0184] [ka]

[0185] (Confirmation of the composition of azo complex salt dyes) For the comparative azo complex dye 2 obtained in comparative synthesis example 2, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (46), the monoazo-monoazo iron complex represented by chemical formula (47), and the disazo-disazo iron complex represented by chemical formula (48) contained in comparative azo complex dye 2 was determined in the same manner as in synthesis examples 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (46): monoazo-monoazo iron complex represented by chemical formula (47): disazo-disazo iron complex represented by chemical formula (48) was 26:72:2.

[0186] (Comparative Synthesis Example 3) 5.3 g (0.011 mol) of the wet cake of disazo dye D-1 obtained in Synthesis Example 1-1, 22.1 g (40% water content, 0.043 mol) of the wet cake of monoazo dye M-1 obtained in Synthesis Example 1-2, and 3.6 g (0.060 mol) of urea were added to 120 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 2:8 mol). Then, 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature. 9.0 g of a 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 7.4 g of a quaternary ammonium salt (benzyltrimethylammonium chloride, C3, manufactured by Lion Specialty Chemicals) was gradually added to the reaction mixture, and the mixture was heated and stirred at 40°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 16.2 g of comparative azo complex dye 3, which contains a disazo-monoazo iron complex represented by the following chemical formula (49), a monoazo-monoazo iron complex represented by the following chemical formula (50), and a disazo-disazo iron complex represented by the following chemical formula (51).

[0187] [ka]

[0188] [ka]

[0189] [ka]

[0190] For the comparative azo complex dye 3 obtained in comparative synthesis example 3, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (49), the monoazo-monoazo iron complex represented by chemical formula (50), and the disazo-disazo iron complex represented by chemical formula (51) contained in comparative azo complex dye 3 was determined in the same manner as in synthesis examples 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (49): monoazo-monoazo iron complex represented by chemical formula (50): disazo-disazo iron complex represented by chemical formula (51) was 29:70:1.

[0191] (Comparative Synthesis Example 4) 8.4 g (0.016 mol) of disazo dye D-6 obtained in Synthesis Example 6-1 and 32.6 g (40% water content, 0.038 mol) of a wet cake of monoazo dye M-6 obtained in Synthesis Example 6-2 were added to 100 g of water and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 90°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature, and 9.0 g of 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 103.6 g of 5% tert-alkyl (C12~C14) primary amine aqueous solution (Dow Chemical; trade name PRIMENE 81-R) was gradually added to the reaction mixture and heated and stirred at 40°C for 1 hour. Subsequently, the precipitate was filtered, washed with water, and dried to obtain 23.1 g of comparative azo complex dye 4 containing a disazo-monoazo iron complex represented by the following chemical formula (52), a monoazo-monoazo iron complex represented by the following chemical formula (53), and a disazo-disazo iron complex represented by the following chemical formula (54).

[0192] [ka]

[0193] [ka]

[0194] [ka]

[0195] For the comparative azo complex dye 4 obtained in comparative synthesis example 4, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (52), the monoazo-monoazo iron complex represented by chemical formula (53), and the disazo-disazo iron complex represented by chemical formula (54) contained in comparative azo complex dye 4 was determined in the same manner as in synthesis examples 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (52): monoazo-monoazo iron complex represented by chemical formula (53): disazo-disazo iron complex represented by chemical formula (54) was 39:54:7.

[0196] (Comparative Synthesis Example 5) 8.4 g (0.016 mol) of disazo dye D-6 obtained in Synthesis Example 6-1 and 32.6 g (40% water content, 0.038 mol) of a wet cake of monoazo dye M-6 obtained in Synthesis Example 6-2 were added to 100 g of water and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 90°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature, and 9.0 g of 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 6.7 g of tributylamine, a tertiary amine, was gradually added to the reaction mixture and heated and stirred at 40°C for 1 hour. Subsequently, the precipitate was filtered, washed with water, and dried to obtain 28.7 g of comparative azo complex dye 5 containing a disazo-monoazo iron complex represented by the following chemical formula (55), a monoazo-monoazo iron complex represented by the following chemical formula (56), and a disazo-disazo iron complex represented by the following chemical formula (57).

[0197] [ka]

[0198] [ka]

[0199] [ka]

[0200] For the comparative azo complex dye 5 obtained in comparative synthesis example 5, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (55), the monoazo-monoazo iron complex represented by chemical formula (56), and the disazo-disazo iron complex represented by chemical formula (57) contained in the comparative azo complex dye 5 was determined in the same manner as in synthesis examples 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (55): monoazo-monoazo iron complex represented by chemical formula (56): disazo-disazo iron complex represented by chemical formula (57) was 46:48:6.

[0201] (Comparative Synthesis Example 6) 8.4 g (0.016 mol) of disazo dye D-6 obtained in Synthesis Example 6-1 and 32.6 g (40% water content, 0.038 mol) of a wet cake of monoazo dye M-6 obtained in Synthesis Example 6-2 were added to 100 g of water and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 90°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature, and 9.0 g of 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 3.1 g of the primary amine 2-ethylhexylamine was gradually added to the reaction mixture and heated and stirred at 40°C for 1 hour. Subsequently, the precipitate was filtered, washed with water, and dried to obtain 18.6 g of comparative azo complex dye 6 containing a disazo-monoazo iron complex represented by the following chemical formula (58), a monoazo-monoazo iron complex represented by the following chemical formula (59), and a disazo-disazo iron complex represented by the following chemical formula (60).

[0202] [ka]

[0203] [ka]

[0204] [ka]

[0205] For the comparative azo complex dye 6 obtained in comparative synthesis example 6, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (58), the monoazo-monoazo iron complex represented by chemical formula (59), and the disazo-disazo iron complex represented by chemical formula (60) contained in the comparative azo complex dye 6 was determined in the same manner as in synthesis examples 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (58): monoazo-monoazo iron complex represented by chemical formula (59): disazo-disazo iron complex represented by chemical formula (60) was 39:55:6.

[0206] (Comparative Synthesis Example 7) 8.4 g (0.016 mol) of disazo dye D-6 obtained in Synthesis Example 6-1 and 32.6 g (40% water content, 0.038 mol) of a wet cake of monoazo dye M-6 obtained in Synthesis Example 6-2 were added to 100 g of water and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 12.4 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 90°C and stirred for 3 hours. After the reaction was complete, the mixture was allowed to cool to room temperature, and 9.0 g of 20% sodium hydroxide aqueous solution was added to adjust the pH to 10.0. 4.0 g of quaternary ammonium salt (tetraethylammonium chloride, 8 carbon atoms) was gradually added to the reaction mixture and heated and stirred at 45-50°C for 1 hour. Subsequently, the precipitate was filtered, washed with water, and dried to obtain 19.1 g of comparative azo complex dye 7 containing a disazo-monoazo iron complex represented by the following chemical formula (61), a monoazo-monoazo iron complex represented by the following chemical formula (62), and a disazo-disazo iron complex represented by the following chemical formula (63).

[0207] [ka]

[0208] [ka]

[0209] [ka]

[0210] For the comparative azo complex dye 7 obtained in comparative synthesis example 7, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (61), the monoazo-monoazo iron complex represented by chemical formula (62), and the disazo-disazo iron complex represented by chemical formula (63) contained in the comparative azo complex dye 7 was determined in the same manner as in synthesis examples 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (61): monoazo-monoazo iron complex represented by chemical formula (62): disazo-disazo iron complex represented by chemical formula (63) was 39:55:6.

[0211] (Comparative Synthesis Example 8) 8.2 g (0.015 mol) of disazo dye D-1 obtained in Synthesis Example 1-1, 11.8 g (0.035 mol) of monoazo dye M-6 obtained in Synthesis Example 6-2, and 3.6 g (0.060 mol) of urea were added to 50 g of N,N-dimethylformamide solution and stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 11.8 g (0.013 mol) of 41% ferric sulfate aqueous solution was added dropwise, and after the addition was complete, the temperature was raised to 120°C and stirred for 3 hours. After the reaction was complete, the reaction solution was cooled to 90°C and poured into a beaker containing 200 g of water. To this, 100.0 g of an aqueous solution of 5% tert-alkyl(C12~C14) primary amine (Dow Chemical Corporation; trade name PRIMENE 81-R) was gradually added, and the mixture was heated and stirred at 35°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 23.3 g of comparative azo complex dye 8, which contains a disazo-monoazo iron complex represented by the following chemical formula (64), a monoazo-monoazo iron complex represented by the following chemical formula (53), and a disazo-disazo iron complex represented by the following chemical formula (45).

[0212] [ka]

[0213] [ka]

[0214] [ka]

[0215] For the comparative azo complex dye 8 obtained in comparative synthesis example 8, the relative abundance (molar ratio) of the disazo-monoazo iron complex represented by chemical formula (64), the monoazo-monoazo iron complex represented by chemical formula (53), and the disazo-disazo iron complex represented by chemical formula (45) contained in the comparative azo complex dye 8 was determined in the same manner as in synthesis examples 1-3. As a result, the molar ratio of the disazo-monoazo iron complex represented by chemical formula (64): monoazo-monoazo iron complex represented by chemical formula (53): disazo-disazo iron complex represented by chemical formula (45) was 31:67:2.

[0216] (Comparative Synthesis Example 9) 8.2 g (0.015 mol) of disazo dye D-6 obtained in Synthesis Example 6-1, 11.8 g (0.035 mol) of monoazo dye M-6 obtained in Synthesis Example 6-2, and 3.6 g (0.060 mol) of urea were added to a solution of 50 g of propylene glycol monomethyl ether and 30 g of ethylene glycol, and the mixture was stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 3.8 g (0.013 mol) of chromium formate was added dropwise, and after the addition was complete, the temperature was raised to 120°C and the mixture was stirred for 3 hours. After the reaction was complete, the reaction solution was cooled to 90°C and poured into a beaker containing 200 g of water. To this, 100.0 g of an aqueous solution of 5% tert-alkyl (C12-C14) primary amine (Dow Chemical Corporation; trade name PRIMENE 81-R) was gradually added, and the mixture was heated and stirred at 35°C for 1 hour. The precipitate was then filtered, washed with water, and dried to obtain 23.3 g of comparative azo complex dye 9 containing a disazo-monoazochrome complex represented by the following chemical formula (65), a monoazo-monoazochrome complex represented by the following chemical formula (66), and a disazo-disazochrome complex represented by the following chemical formula (67).

[0217] [ka]

[0218] [ka]

[0219] [ka]

[0220] For the comparative azo complex dye 9 obtained in comparative synthesis example 9, the relative abundance (molar ratio) of the disazo-monoazochrome complex represented by chemical formula (65), the monoazo-monoazochrome complex represented by chemical formula (66), and the disazo-disazochrome complex represented by chemical formula (67) contained in the comparative azo complex dye 9 was determined in the same manner as in synthesis example 1-3. As a result, the molar ratio of the disazo-monoazochrome complex represented by chemical formula (65):monoazo-monoazochrome complex represented by chemical formula (66):disazo-disazochrome complex represented by chemical formula (67) was 36:59:5.

[0221] (Comparative Synthesis Example 10) 8.2 g (0.015 mol) of disazo dye D-6 obtained in Synthesis Example 6-1, 11.8 g (0.035 mol) of monoazo dye M-6 obtained in Synthesis Example 6-2, and 3.6 g (0.060 mol) of urea were added to a solution of 50 g of propylene glycol monomethyl ether and 30 g of ethylene glycol, and the mixture was stirred at 55°C for 1 hour (disazo dye:monoazo dye = 3:7 mol). 3.8 g (0.013 mol) of chromium formate was added dropwise, and after the addition was complete, the temperature was raised to 120°C and the mixture was stirred for 3 hours. After the reaction was complete, the reaction solution, which had been allowed to cool to 90°C, was placed in a beaker containing 200 g of water. 5.5 g of ethoxylated cocoalkylamine (manufactured by NOF Corporation; Naimine L-201), a secondary amine surfactant, was gradually added to the reaction solution, and the mixture was heated and stirred at 35°C for 1 hour. Subsequently, the precipitate was filtered, washed with water, and dried to obtain 21 g of comparative azo complex dye 10 containing a disazo-monoazochrome complex represented by the following chemical formula (68), a monoazo-monoazochrome complex represented by the following chemical formula (69), and a disazo-disazochrome complex represented by the following chemical formula (70).

[0222] [ka]

[0223] [ka]

[0224] [ka]

[0225] For the comparative azo complex salt dye 10 obtained in comparative synthesis example 10, the relative abundance (molar ratio) of the disazo-monoazochrome complex represented by chemical formula (68), the monoazo-monoazochrome complex represented by chemical formula (69), and the disazo-disazochrome complex represented by chemical formula (70) contained in the comparative azo complex salt dye 9 was determined in the same manner as in synthesis example 1-3. As a result, the molar ratio of the disazo-monoazochrome complex represented by chemical formula (68):monoazo-monoazochrome complex represented by chemical formula (69):disazo-disazochrome complex represented by chemical formula (70) was 31:64:5.

[0226] (Comparative Examples 1-10) The comparative azo complex salt dye and solvent were changed as shown in Table 6, and the thermal stability test was performed in the same manner as in Example 1.

[0227] [Table 6]

[0228] (UV / visible light absorption test before and after heating, standardized by the maximum absorption wavelength) The ultraviolet / visible light absorption spectra were measured for azo metal complex dyes from Example 2 and Comparative Example 2, which differed in their countercations. 6 g of each azo metal complex dye was dissolved in 118 mL of methyl ethyl ketone, a ketone solvent, and the solution was left to stand in a 50°C bath for 4 weeks. The ultraviolet / visible light absorption spectra of the solution after 4 weeks and the solution before testing were measured after dilution to 10 mg / L and normalized by the maximum absorption wavelength. The results are shown in Figures 1 and 2, respectively.

[0229] As is clear from Tables 5 and 6 and Figures 1 and 2, the ink composition using the azo complex salt dye of the present invention showed low decay rate and excellent stability with no precipitates in a 4-week thermal aging test. On the other hand, azo complex salt dyes having primary to tertiary ammonium salts and azo complex salt dyes having quaternary ammonium salts with fewer than 10 carbon atoms in the alkyl group also showed low decay rates in a 4-week thermal aging test. In Comparative Example 7, tetraethylammonium salt showed a low decay rate, but precipitates were observed, indicating that it could not be said to have high solubility stability. As is particularly clear from Figures 1 and 2, the azo metal complex dye of Example 2 showed high stability, as there was almost no difference in absorbance before and after heating across all wavelengths from 350 to 800 nm, especially in the 500 to 700 nm wavelength range. On the other hand, the azo metal complex dye of Comparative Example 2 showed decreased absorbance across all wavelengths from 350 to 800 nm, especially in the 500 to 700 nm wavelength range, due to the secondary nature of the ammonium cation. The decrease in absorbance in the 500 to 700 nm wavelength range indicates a discoloration to a brownish color.

[0230] Therefore, the azo metal complex dye of the present invention, having a salt of an azo metal complex versus anion and a specific quaternary ammonium versus cation, is stable against heat even when incorporated into an ink composition and can maintain its black color. [Industrial applicability]

[0231] The azo metal complex dye of the present invention can improve thermal stability over time. Therefore, ink compositions containing this azo metal complex dye can maintain high blackness without discoloration even when used for extended periods at high temperatures or transported at high temperatures.

Claims

1. The following chemical formula (1) 【Chemistry 1】 (In formula (1), R １ and R ２ R may be the same or different, and is a linear or branched alkyl group having 3 to 10 carbon atoms. ３ R is a cyano group, nitro group, acetyl group, sulfoamide group, or halogen atom. ４ R is a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkoxy group having 1 to 5 carbon atoms. ５ R is singular or plural and is a nitro group, halogen atom, or sulfoamide group. ６ R is singular or plural and is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, a halogen atom, or a nitro group. ７ is a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, M is a trivalent metal, and A ＋ The chemical formula is shown below (2) 【Chemistry 2】 (In formula (2), R ８ to R １１ may be the same or different and are a linear or branched alkyl group having 1 to 20 carbon atoms, a phenyl group or a benzyl group, and the total number of carbon atoms of these alkyl groups is 10 to 40)), and an azo metal complex dye characterized by containing a disazo-monoazo metal complex dye represented by

2. The following chemical formula (3) 【Transformation 3】 (In formula (3), R ５ ~R ７ , M and A ＋ This is the same as formula (1). A monoazo-monoazo metal complex represented by the following chemical formula (4) 【Chemistry 4】 (In formula (4), R １ ~R ４ , M and A ＋ The azo metal complex dye according to claim 1, characterized in that it contains a disazo-disazo metal complex represented by formula (1).

3. The azo metal complex dye according to claim 1, characterized in that, in the chemical formula (1), M is at least one selected from iron, chromium, cobalt, manganese, and titanium.

4. The azo metal complex dye according to claim 2, characterized in that in the chemical formula (3) or (4), M is at least one selected from iron, chromium, cobalt, manganese, and titanium.

5. An ink composition containing an azo metal complex dye and an organic solvent according to any one of claims 1 to 4.

6. An inkjet printer ink composition containing an azo metal complex dye and an organic solvent according to any one of claims 1 to 4.

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