Ink composition for inkjet printing and recording method

Abstract

To provide an ink composition for inkjet printing that has excellent storage stability, and a recording method using the ink composition for inkjet printing.SOLUTION: An ink composition for inkjet printing of the present invention contains a color material having a monochlorotriazine structure, an organic solvent, an amine, a water-soluble organic solvent and water. The pKa(A) is 4.0 or more and 8.5 or less, which is an acid dissociation constant pKa of the organic acid at 25°C, the pKa(B) is 4.0 or more and 8.5 or less, which is an acid dissociation constant pKa of the amine at 25°C, the pKa(A) and the pKa(B) satisfy the relationship of pKa(A)≤pKa(B), and a pH at 25°C is more than 7.0 and less than 9.0.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an ink composition for ink-jet textile printing and a recording method. [Background technology]

[0002] In recent years, the applications of inkjet printing have expanded, and inkjet printing is now used not only in office and home printing machines but also in commercial printing, textile printing, and the like.

[0003] Inkjet inks are required to have excellent ejection stability when used in an inkjet method in order to form desired patterns.

[0004] Inkjet textile printing inks, which are inkjet inks containing reactive dyes and are applied to fabrics, are also used (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-186727 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in inkjet textile printing inks containing a colorant having a monochlorotriazine structure, an undesired reaction of the colorant, more specifically, a reaction in which chlorine atoms are released from the molecules of the colorant, may occur in the inkjet textile printing ink, resulting in a decrease in reactivity with the fabric serving as a recording medium, i.e., in dyeability. In other words, the storage stability of inkjet textile printing inks containing the colorant may be reduced. [Means for solving the problem]

[0007] The present invention has been made to solve the above-mentioned problems, and can be realized as the following application examples.

[0008] The inkjet textile printing ink composition according to an application example of the present invention contains a colorant having a monochlorotriazine structure, an organic acid, an amine, an inorganic base having an acid dissociation constant pKa(C) at 25°C of 10.0 or more, a water-soluble organic solvent, and water, The organic acid has an acid dissociation constant pKa (A) at 25°C of 4.0 or more and 8.5 or less, The acid dissociation constant pKa(B) of the amine at 25°C is 4.0 or more and 8.5 or less, The relationship pKa(A)≦pKa(B) is established between the pKa(A) and the pKa(B), The pH at 25°C is greater than 7.0 and less than 9.0, When the content of the organic acid is XA [mass %], the content of the amine is XB [mass %], and the content of the inorganic base is XC [mass %], the relationship of 0.70≦(XB+XC) / XA≦11.0 is satisfied. death, the water-soluble organic solvent contains 1-(2-hydroxyethyl)-2-pyrrolidone, The inorganic base contains a metal hydroxide .

[0012] Furthermore, in an inkjet textile printing ink composition according to another application example of the present invention, when the content of the organic acid in the inkjet textile printing ink composition is XA [mass %] and the content of the amine in the inkjet textile printing ink composition is XB [mass %], the relationship of 0.10≦XB / XA≦10.0 is satisfied.

[0016] Furthermore, the ink composition for ink-jet textile printing according to another application example of the present invention has a pH at 25°C of more than 7.0 and less than 9.0 after storage at 60°C for 100 hours.

[0017] A recording method according to an application example of the present invention includes a step of ejecting the ink composition for ink-jet textile printing according to an application example of the present invention by an ink-jet method and depositing it onto a recording medium. DETAILED DESCRIPTION OF THE INVENTION

[0018] Preferred embodiments of the present invention will be described in detail below. [1] Ink composition for inkjet printing First, the ink composition for ink-jet textile printing of the present invention will be described.

[0019] The ink composition for ink-jet textile printing of the present invention contains a colorant having a monochlorotriazine structure, an organic acid, an amine, a water-soluble organic solvent, and water. The organic acid has an acid dissociation constant pKa(A) at 25°C of 4.0 or more and 8.5 or less, the amine has an acid dissociation constant pKa(B) at 25°C of 4.0 or more and 8.5 or less, the pKa(A) and the pKa(B) satisfy the relationship pKa(A)≦pKa(B), and the pH at 25°C is greater than 7.0 and less than 9.0.

[0020] This makes it possible to effectively suppress undesired reactions of the coloring material during storage, and to provide an ink composition for inkjet textile printing that has excellent storage stability. The reason why such excellent effects are obtained is believed to be as follows.

[0021] That is, by using an organic acid and an amine that satisfy the above-mentioned conditions in combination, a buffering effect is effectively exhibited, and, for example, even in a high-temperature environment, the pH of the ink composition for inkjet textile printing can be maintained within a predetermined range, and the above-mentioned undesired reactions can be suppressed, which is thought to enable the ink composition for inkjet textile printing to have excellent storage stability.

[0022] On the other hand, if the above conditions are not met, satisfactory results will not be obtained. For example, if an ink composition for inkjet textile printing does not contain an organic acid, the pH of the ink composition is likely to increase when stored in a high-temperature environment, which causes a reaction in which chlorine atoms are released from colorant molecules having a monochlorotriazine structure to proceed, resulting in a problem of a decrease in the dyeability of the ink.

[0023] Furthermore, when an ink composition for inkjet textile printing does not contain an amine, the pH of the ink composition is likely to decrease when stored in a high-temperature environment. Therefore, when such an ink is used in an inkjet printer, the colorant precipitates at the gas-liquid interface near the nozzle of the inkjet head, causing problems such as clogging.

[0024] Furthermore, when an inorganic acid is used instead of an organic acid, the pH of the ink is more likely to change due to external factors. For example, if a foreign substance containing an ionic component is mixed into the ink composition, the pH of the ink is more likely to rise and fluctuate, resulting in the problem of a shorter lifespan of the reactive ink.

[0025] Furthermore, when an inorganic base is used instead of an amine, the pH of the ink is more likely to change due to external factors. For example, if a foreign matter containing an ionic component is mixed into the ink composition, the pH of the ink is more likely to decrease. Therefore, when such an ink is used in an inkjet printer, the colorant will precipitate at the gas-liquid interface near the nozzle of the inkjet head, causing problems such as clogging.

[0026] Furthermore, even if the ink composition for inkjet textile printing contains an organic acid, if the pKa of the organic acid is less than the above-mentioned lower limit, the pH of the ink is likely to fluctuate downward if foreign matter containing ionic components is mixed in from the external environment. Therefore, when such an ink is used in an inkjet printer, the colorant will precipitate at the gas-liquid interface in the vicinity of the nozzle of the inkjet head, causing problems such as clogging.

[0027] Furthermore, even if the ink composition for inkjet textile printing contains an organic acid, if the pKa of the organic acid exceeds the upper limit, the pH of the ink composition is likely to increase when stored in a high-temperature environment. This causes a reaction in which chlorine atoms are released from colorant molecules having a monochlorotriazine structure to proceed, resulting in a problem of shortening the life of the ink.

[0028] Furthermore, even if the ink composition for inkjet textile printing contains an amine, if the pKa of the amine is less than the above-mentioned lower limit, the pH of the ink is likely to decrease and fluctuate if foreign matter containing ionic components is mixed in from the external environment. Therefore, when such an ink is used in an inkjet printer, the colorant will precipitate at the gas-liquid interface in the vicinity of the nozzle of the inkjet head, causing problems such as clogging.

[0029] Furthermore, even if the ink composition for inkjet textile printing contains an amine, if the pKa of the amine exceeds the upper limit, the pH of the ink composition is likely to increase when stored in a high-temperature environment. This causes a reaction in which chlorine atoms are detached from colorant molecules having a monochlorotriazine structure to proceed, resulting in a problem of shortening the life of the ink.

[0030] Furthermore, even if the ink composition for inkjet textile printing contains an organic acid and an amine and the pKa values ​​of each are within the above ranges, unless the relationship described above is satisfied between the acid dissociation constant pKa(A) of the organic acid at 25°C and the acid dissociation constant pKa(B) of the amine at 25°C, the pH of the ink composition is likely to fluctuate, resulting in problems such as a shortened ink life and increased susceptibility to clogging of the inkjet head.

[0031] Furthermore, if the pH at 25°C of the ink composition for inkjet textile printing is too low, when such ink is used in an inkjet printer, the colorant will precipitate at the gas-liquid interface near the nozzle of the inkjet head, causing problems such as clogging.

[0032] Furthermore, if the pH of the ink composition for inkjet textile printing at 25°C is too high, a reaction in which chlorine atoms are released from colorant molecules having a monochlorotriazine structure proceeds, resulting in a problem of shortening the life of the ink.

[0033] In the present invention, the acid dissociation constant refers to the value in water at 25°C. In the present invention, the ink composition for ink-jet textile printing refers to an ink that is ejected by an ink-jet method and used for textile printing.

[0034] Furthermore, when the ink composition for ink-jet textile printing contains multiple types of organic acids, the weighted average value of these values ​​is used as the pKa(A) value.

[0035] When the ink composition for ink-jet textile printing contains a plurality of types of amines, the weighted average value of these amines is used as the pKa(B) value.

[0036] Furthermore, when the organic acid contained in the ink composition for inkjet textile printing is a polyvalent acid, the lowest pKa(A) value is adopted as the pKa(A) of the organic acid.

[0037] Furthermore, when the amine contained in the ink composition for ink-jet textile printing is a polyvalent base, the highest pKa(B) value is adopted as the pKa(B) of the organic amine.

[0038] As described above, in the ink jet printing ink composition of the present invention, the relationship between the pKa(A) and the pKa(B) satisfies pKa(A)≦pKa(B). In particular, it is preferable that the relationship be 0.05≦pKa(B)−pKa(A)≦3.5, it is more preferable that the relationship be 0.3≦pKa(B)−pKa(A)≦2.0, and it is even more preferable that the relationship be 0.5≦pKa(B)−pKa(A)≦1.8. This makes the above-mentioned effects more pronounced.

[0039] As described above, the pH of the ink composition for inkjet textile printing of the present invention at 25°C is more than 7.0 and less than 9.0, and is particularly preferably 7.1 or more and 8.5 or less, and more preferably 7.2 or more and 8.0 or less. This makes the above-mentioned effects more pronounced.

[0040] [1-1] Colorants with a monochlorotriazine structure The ink composition for ink-jet textile printing of the present invention contains a coloring material having a monochlorotriazine structure. In the following description, the coloring material having a monochlorotriazine structure is also referred to as a "specific coloring material."

[0041] As the specific colorant, for example, CI Reactive Yellow 95, CI Reactive Orange 12, CI Reactive Orange 13, CI Reactive Red 31, CI Reactive Red 3:1, CI Reactive Red 245, CI Reactive Red 24:1, CI Reactive Black 39, CI Reactive Black 8, CI Reactive Blue 15:1, CI Reactive Blue 49, CI Reactive Blue 72, etc. are preferable, and other examples include CI Reactive Yellow 2, 3, 7, 15, 17, 18, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 1 5, 27, 37, 39, 42, 57, 69, 76, 81, 84, 85, 86, 87, 92, 102, 105, 111, 125, 135, 136, 137, 142, 143, 145, 151, 160, 161, 165, 167, 168, 175, 176; CI Reactive Orange 1, 4, 5, 7, 11, 15, 16, 20, 30, 35, 56, 64, 67, 69, 70, 72, 74, 82, 84, 86, 87, 91, 92, 93, 95, 99, 107; CI Reactive Red 2, 3, 5, 8, 11, 21, 22, 23, 24, 28, 29, 33, 35, 43, 45, 49, 55, 56, 58, 65, 66, 78, 83, 106, 111, 112, 113, 114, 116, 120, 123, 124, 128, 130, 136, 141, 147, 158, 159, 171, 174, 180, 183, 184, 187, 190, 193, 194, 195, 198, 218, 220, 222, 223, 226, 228, 235; CI Reactive Violet 1, 2, 4, 5, 6, 22, 23, 33, 36, 38; CI Reactive Blue 2, 3, 4, 7, 13 , 14, 15, 19, 21, 25, 27, 28, 29, 38, 39, 41, 50, 52, 63, 69, 71, 77, 79, 89, 104, 109, 112, 113, 114, 116, 119, 120, 122, 137, 140, 143, 147, 160, 161, 162, 163, 168, 171, 176, 182, 184, 191, 194, 195, 198, 203, 204, 207, 209, 211, 214, 220, 221, 222, 231, 235, 236; CI Reactive Green 8, 12, 15, 19, 21; CIReactive Brown 2, 7, 9, 10, 11, 17, 18, 19, 21, 23, 31, 37, 43, 46; CI Reactive Black 5, 13, 14, 31, 34, etc. can be used.

[0042] The content of the specific colorant in the ink composition for inkjet textile printing of the present invention is not particularly limited, but is preferably from 0.5% to 25.0% by mass, more preferably from 1.0% to 20.0% by mass, and even more preferably from 2.0% to 15.0% by mass.

[0043] This makes it easier to ensure sufficient color density in the recording portion formed using the ink jet textile printing ink composition, and also makes it possible to improve the storage stability, ejection stability, clogging recovery property, etc. of the ink jet textile printing ink composition.

[0044] [1-2]Organic acid The ink composition for ink-jet textile printing of the present invention contains an organic acid.

[0045] The acid dissociation constant pKa(A) of the organic acid at 25°C may be 4.0 or more and 8.5 or less, preferably 4.1 or more and 8.0 or less, more preferably 4.2 or more and 7.7 or less, and even more preferably 4.3 or more and 7.5 or less.

[0046] Examples of the organic acid include adipic acid, 2-(N-morpholino)ethanesulfonic acid, N-(2-acetamido)iminodiacetic acid, piperazine-1,4-diethanesulfonic acid, N-(2-acetamido)-2-aminoethanesulfonic acid, 2-hydroxy-3-morpholinopropanesulfonic acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, 3-(N-morpholino)propanesulfonic acid, N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid, 2-hydroxy-N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid, and piperazine-1,4-diethanesulfonic acid. Examples include perazine-1,4-bis(2-hydroxy-3-propanesulfonic acid), 2-hydroxy-3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid, 3-[4-(2hydroxyethyl)-1-piperazinyl]propanesulfonic acid, N,N-bis(2-hydroxyethyl)glycine, N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid, N-cyclohexyl-2-aminoethanesulfonic acid, and N-cyclohexyl-3-aminopropanesulfonic acid, and one or more selected from these can be used in combination.

[0047] Among these, examples of the organic acid include adipic acid, 2-(N-morpholino)ethanesulfonic acid, N-(2-acetamido)iminodiacetic acid, piperazine-1,4-diethanesulfonic acid, N-(2-acetamido)-2-aminoethanesulfonic acid, 2-hydroxy-3-morpholinopropanesulfonic acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, 3-(N-morpholino)propanesulfonic acid, N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid, 2-hydroxy-N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid, piperazine-1,4-bis(2-hydroxy-3-propanesulfonic acid), 2-hydroxy- Preferably, it is at least one selected from the group consisting of 3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid and 3-[4-(2hydroxyethyl)-1-piperazinyl]propanesulfonic acid, and more preferably at least one selected from the group consisting of 2-(N-morpholino)ethanesulfonic acid, N-(2-acetamido)iminodiacetic acid, piperazine-1,4-diethanesulfonic acid, N-(2-acetamido)-2-aminoethanesulfonic acid, 2-hydroxy-3-morpholinopropanesulfonic acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, and 3-(N-morpholino)propanesulfonic acid.

[0048] The content of the organic acid in the ink composition for inkjet textile printing of the present invention is not particularly limited, but is preferably from 0.01% by mass to 1.0% by mass, more preferably from 0.02% by mass to 0.7% by mass, and even more preferably from 0.04% by mass to 0.5% by mass.

[0049] This makes it possible to improve the storage stability, ejection stability, clogging recovery property, and the like of the ink composition for ink-jet textile printing.

[0050] [1-3]amine The ink composition for ink-jet textile printing of the present invention contains an amine.

[0051] The acid dissociation constant pKa(B) of the amine at 25°C may be 4.0 or more and 8.5 or less, preferably 5.0 or more and 8.4 or less, more preferably 6.0 or more and 8.3 or less, and even more preferably 7.0 or more and 8.2 or less.

[0052] Examples of the amine include triethanolamine, triisopropanolamine, dimethylaminoethanol, ethanolamine, methanolamine, heptanolamine, isoethanol, propanolamine, isopropylamine, n-hexylamine, didecylamine, dioctylamine, and tri-n-octylamine. One or more selected from these may be used in combination.

[0053] Among these, the amine is preferably at least one selected from the group consisting of alkanolamines such as triethanolamine, triisopropanolamine, dimethylaminoethanol, ethanolamine, methanolamine, heptanolamine, isoethanol, and propanolamine, and more preferably at least one of triethanolamine and triisopropanolamine.

[0054] The content of the amine in the ink composition for inkjet textile printing of the present invention is not particularly limited, but is preferably from 0.01% by mass to 1.5% by mass, more preferably from 0.03% by mass to 1.0% by mass, and even more preferably from 0.08% by mass to 0.5% by mass.

[0055] This makes it possible to improve the storage stability, ejection stability, clogging recovery property, and the like of the ink composition for ink-jet textile printing.

[0056] When the content of the organic acid in the ink composition for inkjet textile printing is XA [mass %] and the content of the amine is XB [mass %], it is preferable that the relationship of 0.10≦XB / XA≦10.0 is satisfied, it is more preferable that the relationship of 0.50≦XB / XA≦7.0 is satisfied, and it is even more preferable that the relationship of 1.0≦XB / XA≦4.0 is satisfied.

[0057] This makes it possible to improve the storage stability, ejection stability, clogging recovery property, and the like of the ink composition for ink-jet textile printing.

[0058] [1-4] Water-soluble organic solvents The ink composition for ink-jet textile printing of the present invention contains a water-soluble organic solvent.

[0059] This allows the organic acid and the amine to exist in a sufficiently dissociated state in the inkjet textile printing ink composition, ensuring that these functions are fully exerted, and improving the storage stability of the inkjet textile printing ink composition. Furthermore, the moisturizing properties of the inkjet textile printing ink composition can be improved, and unintended precipitation of the solid content of the inkjet textile printing ink composition due to drying in an inkjet head or the like can be more effectively prevented. Furthermore, the viscosity of the inkjet textile printing ink composition can be more suitably adjusted. As a result, the ejection stability of the inkjet textile printing ink composition when used in an inkjet method can be improved.

[0060] The water-soluble organic solvent may be any organic solvent that is soluble in water, and for example, an organic solvent having a solubility in water at 25° C. of 1 g / 100 g water or more can be suitably used.

[0061] The water-soluble organic solvent preferably contains a component whose boiling point at 1 atmospheric pressure is 260° C. or higher and 350° C. or lower.

[0062] This can further improve the moisture retention of the inkjet textile printing ink composition, and more effectively prevent the unintended precipitation of solids from the inkjet textile printing ink composition due to drying in an inkjet head or the like. Furthermore, even if clogging occurs in the inkjet head, the clogging can be easily eliminated. That is, the inkjet textile printing ink composition can have excellent clogging recovery properties. This further improves the ejection stability of the inkjet textile printing ink composition when ejected using an inkjet method. Furthermore, after the inkjet textile printing ink composition is ejected, it can be volatilized relatively easily when necessary, and more effectively prevent the water-soluble organic solvent from unintendedly remaining in the recorded material produced.

[0063] Furthermore, the proportion of components that satisfy the above boiling point conditions in the entire water-soluble organic solvent is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more and 50% by mass or less. This makes the above-mentioned effects more pronounced.

[0064] Examples of such water-soluble organic solvents include alcohols such as monohydric alcohols and polyhydric alcohols; glycol ethers; and lactams having a lactam structure in the molecule, and one or more selected from these can be used in combination.

[0065] In particular, the water-soluble organic solvent preferably contains a component having a lactam structure.

[0066] This allows the organic acid and the amine to be more suitably dissociated in the ink composition for inkjet textile printing, thereby improving the storage stability of the ink composition for inkjet textile printing, and also improving the ejection stability, clogging recovery property, etc. of the ink composition for inkjet textile printing.

[0067] When the water-soluble organic solvent contains a component having a lactam structure, the proportion of the component having a lactam structure in the entire water-soluble organic solvent is preferably 5.0 mass% or more, more preferably 10.0 mass% or more and 70.0 mass% or less, and even more preferably 15.0 mass% or more and 40.0 mass% or less. This makes the above-mentioned effects more pronounced.

[0068] Examples of components having a lactam structure include 2-pyrrolidone, ε-caprolactam, 1-(2-hydroxyethyl)-2-pyrrolidone, 2-acetidinone, 2-piperidone, 4-ethyl-2-acetidinone, N-methyl-2-pyrrolidone, γ-butyrolactone, and 3-amino-2-piperidone. The water-soluble organic solvent may contain one or more selected from these, but preferably contains at least one selected from the group consisting of 2-pyrrolidone, ε-caprolactam, and 1-(2-hydroxyethyl)-2-pyrrolidone, and more preferably contains 1-(2-hydroxyethyl)-2-pyrrolidone.

[0069] This allows the organic acid and the amine to be more suitably dissociated in the ink composition for inkjet textile printing, thereby improving the storage stability of the ink composition for inkjet textile printing. In addition, it is possible to more effectively prevent the solid content of the ink composition from unintentionally precipitating due to drying in an inkjet head or the like, improve clogging recovery, and improve the ejection stability of the ink composition for inkjet textile printing.

[0070] When the water-soluble organic solvent contains 1-(2-hydroxyethyl)-2-pyrrolidone, the proportion of 1-(2-hydroxyethyl)-2-pyrrolidone in the entire water-soluble organic solvent is preferably 0.5% by mass or more, more preferably 1.0% by mass or more and 70.0% by mass or less, and even more preferably 3.0% by mass or more and 40.0% by mass or less. This makes the above-mentioned effects more pronounced.

[0071] Examples of monohydric alcohols include alkyl alcohols having a linear or branched alkyl group with 3 to 20 carbon atoms.

[0072] Examples of polyhydric alcohols include alkanediols such as ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,2-octanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and 2-ethyl-1,3-hexanediol; dihydric alcohols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and dipropylene glycol; and trihydric alcohols such as trimethylolpropane and glycerin.

[0073] Examples of glycol ethers include alkylene glycol monoethers and alkylene glycol diethers.

[0074] Examples of alkylene glycol monoethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether.

[0075] Examples of alkylene glycol diethers include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, and dipropylene glycol diethyl ether.

[0076] The content of the water-soluble organic solvent in the ink composition for inkjet textile printing of the present invention is not particularly limited, but is preferably from 1.0% to 50.0% by mass, more preferably from 3.0% to 45.0% by mass, and even more preferably from 5.0% to 38.0% by mass.

[0077] This makes it possible to more suitably improve the moisturizing properties of the ink jet printing ink composition while making the viscosity of the ink jet printing ink composition more suitable, thereby further improving the ejection stability of the ink jet printing ink composition when used in an ink jet method.

[0078] [1-5]Water The ink composition for ink-jet textile printing of the present invention contains water. Water is a component that functions as a solvent that dissolves the specific coloring material in the ink composition for inkjet textile printing, for example.

[0079] Furthermore, by including water in the inkjet textile printing ink composition, the organic acid and the amine can be present in a sufficiently dissociated state in the inkjet textile printing ink composition, and these functions can be reliably exhibited, thereby making it possible to provide the inkjet textile printing ink composition with excellent storage stability.

[0080] The water content in the ink composition for inkjet textile printing of the present invention is preferably 40.0% by mass or more and 80.0% by mass or less, more preferably 45.0% by mass or more and 75.0% by mass or less, and even more preferably 50.0% by mass or more and 70.0% by mass or less.

[0081] This makes it possible to more reliably adjust the viscosity of the ink composition for inkjet textile printing to a suitable value, and further improves the ejection stability by the inkjet method.

[0082] Furthermore, when the content of water in the inkjet textile printing ink composition is XW [mass %] and the content of the water-soluble organic solvent in the inkjet textile printing ink composition is XH [mass %], XH / XW is preferably 0.10 or more and 0.65 or less, more preferably 0.20 or more and 0.60 or less, and even more preferably 0.30 or more and 0.55 or less.

[0083] This makes it possible to more suitably improve the moisturizing properties of the ink jet printing ink composition while making the viscosity of the ink jet printing ink composition more suitable, thereby further improving the ejection stability and the like of the ink jet printing ink composition when used in an ink jet method.

[0084] [1-6] Inorganic bases The ink composition for ink-jet textile printing of the present invention may further contain an inorganic base having an acid dissociation constant pKa (C) at 25°C of 10.0 or more.

[0085] This makes it possible to more reliably adjust the pH of the ink composition for inkjet textile printing to fall within a suitable range, thereby improving the storage stability and other properties of the ink composition for inkjet textile printing.

[0086] The pKa(C) may be 10.0 or more, preferably 11.0 or more and 15 or less, and more preferably 12.0 or more and 13.5 or less. This makes the above-mentioned effects more pronounced.

[0087] Examples of the inorganic base include metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, and cesium hydroxide, and metal hydroxides are preferred. This makes the above-mentioned effects more pronounced.

[0088] The content of the inorganic base in the ink composition for inkjet textile printing of the present invention is not particularly limited, but is preferably from 0.001% by mass to 0.3% by mass, more preferably from 0.003% by mass to 0.2% by mass, and even more preferably from 0.004% by mass to 0.1% by mass. This makes the above-mentioned effects more pronounced.

[0089] When the content of the organic acid in the inkjet textile printing ink composition is XA [% by mass], the content of the amine is XB [% by mass], and the content of the inorganic base is XC [% by mass], it is preferable that the relationship of 0.11≦(XB+XC) / XA≦11.0 is satisfied, it is more preferable that the relationship of 0.70≦(XB+XC) / XA≦7.2 is satisfied, and it is even more preferable that the relationship of 1.1≦(XB+XC) / XA≦4.1 is satisfied.

[0090] This makes it possible to improve the storage stability, ejection stability, clogging recovery property, and the like of the ink composition for ink-jet textile printing.

[0091] [1-7] Other colorants The ink composition for inkjet textile printing of the present invention contains the above-mentioned specific coloring material, i.e., a coloring material having a monochlorotriazine structure, but may further contain coloring materials other than the specific coloring material in addition to the specific coloring material. Hereinafter, coloring materials other than the specific coloring material will also be referred to as "other coloring materials."

[0092] The content of other coloring materials in the ink composition for inkjet textile printing of the present invention is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0.1% by mass or less.

[0093] When the ink composition for ink-jet textile printing of the present invention contains a plurality of components as other coloring materials, the sum of the contents of these components preferably falls within the above range.

[0094] [1-8] Other ingredients The ink composition for ink-jet textile printing of the present invention may contain components other than the components described above. Hereinafter, such components may also be referred to as "other components."

[0095] Examples of other components include acids other than the organic acids mentioned above; bases other than the amines and inorganic bases mentioned above; chelating agents; preservatives; mildew inhibitors; rust inhibitors; flame retardants; various dispersants; surfactants; antioxidants; ultraviolet absorbers; oxygen absorbers; dissolution aids; and penetrating agents.

[0096] Examples of chelating agents include ethylenediaminetetraacetate, etc. Examples of preservatives and antifungal agents include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazolin-3-one, 4-chloro-3-methylphenol, etc. Examples of rust inhibitors include benzotriazole, etc.

[0097] As the antiseptic / antifungal agent, for example, a compound having an isothiazolinone ring structure in the molecule can be suitably used.

[0098] As the surfactant, various surfactants such as anionic surfactants, cationic surfactants, and nonionic surfactants can be used.

[0099] The content of other components is preferably 6.0% by mass or less, and more preferably 5.0% by mass or less. The lower limit of the content of other components is 0% by mass.

[0100] [1-9]Other The ink composition for inkjet textile printing of the present invention preferably has a pH at 25°C after storage at 60°C for 100 hours of more than 7.0 and less than 9.0, more preferably 7.1 or more and 8.5 or less, and even more preferably 7.2 or more and 8.0 or less.

[0101] This makes it possible to improve the storage stability of the ink composition for ink-jet textile printing.

[0102] The surface tension of the ink composition for inkjet textile printing of the present invention at 25°C is not particularly limited, but is preferably from 20 mN / m to 60 mN / m, more preferably from 25 mN / m to 50 mN / m, and even more preferably from 30 mN / m to 40 mN / m.

[0103] This makes it more difficult for nozzle clogging of the inkjet head to occur, further improving the ejection stability of the ink composition for inkjet textile printing. Furthermore, even if nozzle clogging does occur, recovery by capping the nozzle can be more excellent.

[0104] The surface tension can be measured by the Wilhelmy method or the Ring method using a surface tensiometer (e.g., DY-300, DY-500, DY-700, etc., manufactured by Kyowa Interface Science Co., Ltd.).

[0105] The viscosity of the ink composition for ink-jet textile printing of the present invention at 25° C. is preferably from 2 mPa·s to 10 mPa·s, and more preferably from 3 mPa·s to 8 mPa·s.

[0106] This provides the ink composition for ink-jet textile printing with better ejection stability when subjected to an ink-jet method.

[0107] The viscosity can be determined by measurement using a vibration viscometer, a rotational viscometer, a capillary viscometer, or a falling ball viscometer. For example, when using a vibration viscometer, the viscosity can be determined by measurement in accordance with JIS Z8809.

[0108] The ink composition for inkjet textile printing of the present invention may be any ink composition that can be ejected by an inkjet method. Examples of the inkjet method include on-demand methods such as a charge deflection method, a continuous method, a piezoelectric method, and a Bubble Jet (registered trademark) method. However, it is particularly preferable that the ink composition for inkjet textile printing of the present invention be ejected from an inkjet head that uses a piezoelectric vibrator.

[0109] This makes it possible to more effectively prevent the coloring material from being altered in the inkjet head, and to improve the ejection stability by the inkjet method.

[0110] Furthermore, the ink composition for inkjet textile printing of the present invention is ejected by an inkjet method. However, the ink composition for inkjet textile printing is not limited to being ejected directly onto a final recording medium, and may be ejected once onto an intermediate transfer medium and then transferred onto a final recording medium.

[0111] In particular, the ink composition for inkjet textile printing of the present invention may be one that is once ejected onto an intermediate transfer medium and then transferred to a fabric, which is a recording medium, by sublimation, i.e., one that is subjected to sublimation transfer textile printing.

[0112] [2] Inkjet textile printing ink composition set Next, the ink composition set for ink-jet textile printing according to the present invention will be described.

[0113] The ink jet textile printing ink composition set according to the present invention includes a plurality of ink jet textile printing ink compositions, at least one of which is the ink jet textile printing ink composition according to the present invention described above.

[0114] It is sufficient that at least one of the multiple inkjet textile printing ink compositions constituting the inkjet textile printing ink composition set according to the present invention is the above-mentioned inkjet textile printing ink composition of the present invention, and the inkjet textile printing ink composition set according to the present invention may also include an inkjet textile printing ink composition other than the above-mentioned inkjet textile printing ink composition of the present invention.

[0115] The ink composition set for inkjet textile printing according to the present invention preferably includes three inkjet textile printing ink compositions corresponding to the three primary colors, i.e., cyan, magenta, and yellow. The three primary colors may be further subdivided based on their color densities. For example, the ink composition set may include light cyan, light magenta, and light yellow in addition to cyan, magenta, and yellow.

[0116] The ink composition set for ink-jet textile printing according to the present invention may also include an achromatic ink, more specifically, a black ink.

[0117] [3] Recording method Next, the recording method of the present invention will be described.

[0118] The recording method of the present invention comprises a step of ejecting the ink composition for ink-jet textile printing of the present invention by an ink-jet method and depositing it onto a recording medium.

[0119] This makes it possible to provide a recording method that is excellent in ejection stability and clogging recovery properties when using an ink jet method, and that can stably produce recorded matter.

[0120] In particular, the recording method of this embodiment includes a discharge step of applying the ink composition for inkjet textile printing of the present invention to a recording medium by an inkjet system, and a dyeing treatment step of dyeing the applied ink composition for inkjet textile printing onto the recording medium. In the following explanation, a case where a fabric is used as the recording medium will be representatively described.

[0121] [3-1] Discharge process In the ejection step, the ink composition for inkjet textile printing of the present invention is ejected as droplets by an inkjet method, and the droplets are deposited on a fabric, which is a recording medium. A desired image is thereby formed. A plurality of types of inkjet textile printing ink compositions, for example, a plurality of types of inkjet textile printing ink compositions of the present invention, may be used to form the image.

[0122] The inkjet method for ejecting the ink composition for inkjet textile printing may be any method, and examples thereof include on-demand methods such as a charge deflection method, a continuous method, a piezo method, and a bubble jet (registered trademark) method.

[0123] [3-2] Dyeing process In the dyeing process, the colorant attached to the fabric, which is the recording medium, is fixed. The dyeing treatment step is usually carried out under high temperature and humid conditions.

[0124] The treatment temperature in the dyeing treatment step is not particularly limited, but is preferably 90°C or higher and 150°C or lower, more preferably 95°C or higher and 130°C or lower, and even more preferably 98°C or higher and 120°C or lower.

[0125] This makes it possible to more effectively prevent undesired alteration, deterioration, etc. of the fabric serving as the recording medium and the components of the ink composition for ink jet textile printing, while more efficiently fixing the colorant.

[0126] The treatment time for the dyeing treatment step is not particularly limited, but is preferably from 1 minute to 120 minutes, more preferably from 2 minutes to 90 minutes, and even more preferably from 3 minutes to 60 minutes.

[0127] This makes it possible to improve the dyeability of the coloring material to the fabric, which is the recording medium, and also improve the productivity of the dyed product.

[0128] For the high-temperature humidification treatment in the dyeing treatment step, various steamers, such as Steamer DHe type manufactured by Matisse, can be used.

[0129] The recording method according to the present invention may include steps other than the ejection step and the dyeing treatment step, if necessary.

[0130] For example, prior to the ejection step, a pretreatment step may be included in which a fabric serving as a recording medium is pretreated.

[0131] For the pretreatment, for example, a known pretreatment agent can be used, and the pretreatment agent generally contains a sizing agent, a pH adjuster, and a hydrotropic agent.

[0132] Suitable examples of adhesives that can be used include natural gums, starches, seaweed, plant skins, cellulose derivatives, modified starch, modified natural gum, sodium alginate, algin derivatives, synthetic glues, emulsions, and the like.

[0133] Examples of natural gums include guar and locust bean. Examples of seaweed include funori seaweed. Examples of plant skins include pectic acid. Examples of cellulose derivatives include methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, etc. Examples of processed starches include roasted starch, alpha starch, carboxymethyl starch, carboxyethyl starch, hydroxyethyl starch, etc. Examples of processed natural gums include shirat gum and roasted bean gum. Examples of synthetic glues include polyvinyl alcohol and polyacrylic esters.

[0134] As the pH adjuster, for example, acid ammonium salts such as ammonium sulfate and ammonium tartrate can be suitably used.

[0135] As the hydrotropic agent, various ureas such as alkyl ureas such as urea, dimethyl urea, thiourea, monomethyl thiourea, and dimethyl thiourea can be used. The pretreatment agent may further contain, for example, silica.

[0136] Furthermore, for example, after the dyeing treatment step, a washing step may be included, if necessary, in which the fabric to which the dye has been fixed is washed.

[0137] The washing step can be carried out, for example, by rubbing the dye-fixed fabric with tap water, and then immersing it in warm water at 40°C to 70°C in a washing solution containing a nonionic soaping agent while stirring appropriately. The immersion time in the washing solution can be, for example, 5 minutes to 60 minutes. The detergent can then be removed by hand-washing the fabric while adding tap water to the washing solution.

[0138] [3-3]Fabric Next, a description will be given of a fabric as a recording medium to which the ink composition for ink-jet textile printing is applied.

[0139] As the fabric, various woven fabrics such as plain weave, twill weave, satin weave, varied plain weave, varied twill weave, varied satin weave, patterned weave, single-layer weave, double weave, multiple weave, warp pile weave, weft pile weave, and leno weave can be used.

[0140] The thickness of the fibers constituting the fabric can be, for example, 10 d or more and 100 d or less.

[0141] Examples of fibers that can be used to make fabrics include polyester fibers, nylon fibers, triacetate fibers, diacetate fibers, polyamide fibers, cellulose fibers, and blends of two or more of these fibers. Blends of these fibers with regenerated fibers such as rayon or natural fibers such as cotton, silk, and wool may also be used, but fabrics containing cellulose fibers are preferred. This makes it possible to improve the dyeability of the coloring material.

[0142] [4] Dyed fabrics The dyed material, which is a recorded material according to the present invention, is produced using the ink composition for inkjet textile printing according to the present invention described above, and can be produced using the recording method described above.

[0143] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these.

[0144] For example, in the above-described embodiment, the ink jet printing ink composition of the present invention is applied to a fabric as a recording medium. However, any recording medium may be used as the recording medium to which the ink jet printing ink composition of the present invention is applied. For example, the recording medium to which the ink jet printing ink composition of the present invention is applied may be an intermediate transfer medium, such as plain paper or a recording medium provided with an ink-receiving layer, such as ink jet paper or coated paper. When such an intermediate transfer medium is used, the ink jet printing ink composition of the present invention can be applied to a thermal transfer printing method in which the intermediate transfer medium to which the ink jet printing ink composition of the present invention has been applied is heated to sublimate and transfer a colorant from the intermediate transfer medium to a member to be dyed. [Example]

[0145] Next, specific examples of the present invention will be described. [5] Preparation of ink composition for inkjet printing

[0146] Example 1 The components shown in Table 1 were placed in a specified container in the specified ratio and mixed and stirred for 2 hours using a stirrer.The mixture was then filtered through a membrane filter with a pore size of 1 μm to obtain an inkjet textile printing ink composition having the composition shown in Table 1.

[0147] (Examples 2 to 15) Inkjet textile printing ink compositions were prepared in the same manner as in Example 1, except that the types of components used in preparing the inkjet textile printing ink compositions and the blending ratios of each component were changed to obtain the compositions shown in Tables 1 and 2.

[0148] (Comparative Examples 1 to 4) Inkjet textile printing ink compositions were prepared in the same manner as in Example 1, except that the types of components used in preparing the inkjet textile printing ink compositions and the blending ratios of each component were changed to obtain the compositions shown in Table 2.

[0149] The inkjet printing ink composition conditions for each of the Examples and Comparative Examples are summarized in Tables 1 and 2. In the tables, CI Reactive Yellow 95 is referred to as "RY95," CI Reactive Orange 12 as "RO12," CI Reactive Orange 13 as "RO13," CI Reactive Red 31 as "RR31," CI Reactive Red 3:1 as "RR3:1," CI Reactive Red 245 as "RR245," CI Reactive Red 24:1 as "RR24:1," CI Reactive Black 39 as "RK39," CI Reactive Black 8 as "RK8," CI Reactive Blue 15:1 as "RR15," CI Reactive Yellow 95 ... "RB15:1", CI Reactive Blue 49 "RB49", CI Reactive Blue 72 "RB72", 2-pyrrolidone "S1", ε-caprolactam "S2", 1-(2-hydroxyethyl)-2-pyrrolidone "S3", 1,2-propanediol "S4", diethylene glycol monobutyl ether "S5", triethylene glycol monobutyl ether "S6", adipic acid "A1", 2-(N-morpholino)ethanesulfonic acid "A2", N-(2-acetonitrile) Amido)iminodiacetic acid is "A3", piperazine-1,4-diethanesulfonic acid is "A4", N-(2-acetamido)-2-aminoethanesulfonic acid is "A5", 2-hydroxy-3-morpholinopropanesulfonic acid is "A6", N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid is "A7", 3-(N-morpholino)propanesulfonic acid is "A8", N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid is "A9", 2-hydroxy-N-tris(hydroxy (hydroxymethyl)methyl-3-aminopropanesulfonic acid is "A10", piperazine-1,4-bis(2-hydroxy-3-propanesulfonic acid) is "A11", 2-hydroxy-3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid is "A12", 3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid is "A13", formic acid is "A'1", triethanolamine is "B1", triisopropanolamine is "B2", 2-amino-2-methyl-1,3-Propanediol is indicated as "B'1," Olfine PD002W (manufactured by Nisshin Chemical Industry Co., Ltd.) as a surfactant is indicated as "PD002W," Proxel GXL (manufactured by Lonza Japan) as a preservative is indicated as "GXL," and trishydroxymethylaminomethane is indicated as "Tris." In the table, the content of each component is indicated in mass%. The boiling point values ​​shown in the table are those at 1 atmosphere, the pKa values ​​are those at 25°C, the η values ​​are those at 25°C measured in accordance with JIS Z8809 using a vibration viscometer (Senicoq VM-100), and the pH values ​​are those at 25°C. The viscosity values ​​in the table are indicated in mPa·s. The inkjet printing ink compositions of each of the examples above all had a surface tension in the range of 30 mN / m to 40 mN / m. The surface tension was measured by the Wilhelmy method at 25°C using a surface tensiometer (DY-300, manufactured by Kyowa Interface Science Co., Ltd.).

[0150] [Table 1]

[0151] [Table 2]

[0152] [6] Evaluation The ink compositions for inkjet textile printing of the above-described Examples and Comparative Examples were evaluated as follows.

[0153] [6-1] Storage stability (pH) First, the pH at 25°C was determined for the inkjet textile printing ink compositions of each of the Examples and Comparative Examples immediately after production. Each inkjet textile printing ink composition was then filled into an ink cartridge and left to stand in an environment at 60°C for 10 days. The cartridge temperature was then returned to 25°C, and the pH was measured. The absolute value of the difference in pH before and after leaving the ink in an environment at 60°C was determined, and the results were evaluated according to the following criteria. The smaller the absolute value of the difference in pH before and after leaving the ink in an environment at 60°C, the better the storage stability. A grade of B or higher was determined to be good.

[0154] A: The absolute value of the difference in pH before and after exposure to a 60°C environment is less than 1.0. B: The absolute value of the difference in pH before and after leaving the sample in a 60°C environment is 1.0 or more and less than 2.0. C: The absolute value of the difference in pH before and after leaving in an environment of 60°C is 2.0 or more and less than 3.0. D: The absolute value of the difference in pH before and after leaving in a 60°C environment is 3.0 or more and less than 4.0. E: The absolute value of the difference in pH before and after exposure to a 60°C environment is 4.0 or more.

[0155] [6-2] Storage stability (color development) First, the ink composition for inkjet textile printing of each of the Examples and Comparative Examples was filled into a cartridge for an inkjet printer PX-G930 (manufactured by Seiko Epson Corporation).

[0156] Thereafter, droplets of the ink composition for inkjet textile printing were ejected from the inkjet printer and deposited on the pretreated fabric, forming a predetermined image with a resolution of 720 × 720 dpi.

[0157] The fabric on which the image was formed was steamed at 102°C for 10 minutes, then washed with an aqueous solution containing 0.2% by mass of Laccol STA (surfactant, manufactured by Meisei Chemical Industry Co., Ltd.) at 90°C for 10 minutes and dried to obtain the initial printed sample.

[0158] Next, each ink cartridge filled with the ink composition for inkjet textile printing was left to stand for 10 days in an environment of 60° C. Thereafter, these cartridges were installed in the inkjet printer, and images were formed in the same manner as above to prepare evaluation samples.

[0159] The initial printed sample and the evaluation sample were measured using a colorimeter (X-RITE, Gretag Macbeth Spectrolino), and the L of the image was measured. * value, a * value, b * The color difference ΔE between the initial printed sample and the evaluation sample was calculated from these values ​​and evaluated according to the following criteria. The smaller the ΔE, the better the storage stability of the inkjet textile printing ink composition. A grade of B or higher was rated as good.

[0160] A: ΔE is less than 2. B: ΔE is 2 or more and less than 4. C: ΔE is 4 or more and less than 6. D: ΔE is 6 or more and less than 8. E: ΔE is 8 or more.

[0161] [6-3] Clogging reliability First, the ink composition for inkjet textile printing of each of the Examples and Comparative Examples was filled into a cartridge for an inkjet printer PX-G930 (manufactured by Seiko Epson Corporation).

[0162] Thereafter, a cleaning operation was performed on the inkjet printer with the cartridge attached, and the ink composition for inkjet textile printing was filled into the flow path of the inkjet printer. A nozzle check pattern was then printed to confirm that there were no filling defects or nozzle clogging. The head was then left in a state where it was not returned to the home position, i.e., no head cap was placed on the head nozzle surface, and the printer was left standing for one week in an environment of 35°C / 40% RH.

[0163] Thereafter, a nozzle check pattern was printed and the nozzle discharge state was observed to evaluate the clogging of the inkjet head caused by the inkjet textile printing ink composition according to the following criteria, with B or higher being considered a good level.

[0164] A: The ink jet textile printing ink composition was normally ejected from all nozzles after one cleaning operation. B: The ink composition for inkjet textile printing was normally ejected from all nozzles within two or three cleaning operations. C: The ink composition for inkjet textile printing was normally ejected from all nozzles within a range of 4 to 7 cleaning operations. D: The ink jet textile printing ink composition was normally ejected from all nozzles within a range of 8 to 10 cleaning operations. E: Cleaning operations were required 11 or more times before the ink jet printing ink composition was normally ejected from all nozzles, or there were nozzles from which the ink jet printing ink composition did not normally eject even after cleaning operations were performed 11 or more times.

[0165] [6-4] Continuous discharge stability First, the ink composition for inkjet textile printing of each of the Examples and Comparative Examples was filled into a cartridge for an inkjet printer PX-G930 (manufactured by Seiko Epson Corporation).

[0166] After that, 1,000 sheets of A4 size plain paper were printed in a continuous solid state in an environment of 35°C / 40% RH, and the average number of sheets that could be printed in a continuous state without cleaning was calculated and evaluated according to the following evaluation criteria, with B or above being considered a good level.

[0167] During printing, if at least one of the following print defects occurred, namely irregular dots, missing dots, or misaligned dots, printing was stopped and a cleaning operation was performed to recover the print. If multiple cleaning operations were required to recover the print, these were counted as one defect. In addition, if printing was temporarily stopped due to an ink cartridge running out of ink, or if the print defect was clearly caused by an ink run out, this was not counted, and the ink cartridge was promptly replaced and printing resumed.

[0168] A: The average number of continuous prints is 100 or more. B: The average number of consecutive prints is between 70 and 100. C: The average number of consecutive prints is between 40 and 70 sheets. D: The average number of consecutive prints is 10 or more but less than 40. E: The average number of consecutive prints is less than 10. These results are summarized in Table 3.

[0169] [Table 3]

[0170] As is clear from Table 3, excellent results were obtained in the present invention. In contrast, satisfactory results were not obtained in the comparative examples.

Claims

1. The ink contains a colorant having a monochlorotriazine structure, an organic acid, an amine, an inorganic base having an acid dissociation constant pKa (C) at 25°C of 10.0 or more, a water-soluble organic solvent, and water, The organic acid has an acid dissociation constant pKa(A) at 25°C of 4.0 or more and 8.5 or less, the acid dissociation constant pKa(B) of the amine at 25°C is 4.0 or more and 8.5 or less; the relationship pKa(A)≦pKa(B) is satisfied between the pKa(A) and the pKa(B), The pH at 25°C is greater than 7.0 and less than 9.0, When the content of the organic acid is XA [% by mass], the content of the amine is XB [% by mass], and the content of the inorganic base is XC [% by mass], the relationship of 0.70≦(XB+XC) / XA≦11.0 is satisfied, the water-soluble organic solvent contains 1-(2-hydroxyethyl)-2-pyrrolidone, The ink composition for inkjet textile printing, wherein the inorganic base contains a metal hydroxide.

2. 2. The ink composition for inkjet textile printing according to claim 1, wherein, when a content of the organic acid in the ink composition is XA [mass %] and a content of the amine in the ink composition is XB [mass %], the relationship of 0.10≦XB / XA≦10.0 is satisfied.

3. The ink composition for ink-jet textile printing according to claim 1 or 2, wherein the pH at 25°C after storage at 60°C for 100 hours is greater than 7.0 and less than 9.

0.

4. A recording method, comprising a step of ejecting the ink composition for ink-jet textile printing according to claim 1 onto a recording medium by an ink-jet method.

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