JP7479342B2 - Dye dispersion and method for printing hydrophobic fibers - Google Patents

Description

The present invention relates to a dye dispersion and a method for printing hydrophobic fibers using the same.

In recent years, a recording method for plateless printing using inkjet printing has been proposed, and inkjet printing is also used for printing on fibers, including cloth. Compared to conventional printing methods such as screen printing, inkjet printing has various advantages, such as no platemaking, resource saving, energy saving, and ease of high-resolution expression. Here, hydrophobic fiber fabrics such as polyester fibers are generally dyed with colorants that are insoluble in water. Therefore, as an aqueous ink for printing hydrophobic fibers using inkjet recording methods, it is generally necessary to use a dispersion ink in which a water-insoluble colorant is dispersed in water and which has good performance such as dispersion stability. Inkjet printing methods for hydrophobic fibers, such as polyester fibers, can be broadly divided into the following two methods. The direct printing method involves applying (printing) ink directly onto the fibers, and then using heat treatment such as high-temperature steaming to cause the dye in the ink to adhere to the fibers. The sublimation transfer method involves applying (printing) ink onto an intermediate recording medium (such as special transfer paper), overlapping the ink-applied surface of the intermediate recording medium with hydrophobic fibers, and then using heat to transfer the dye from the intermediate recording medium to the fibers.

Of the above, the sublimation transfer method is mainly used for printing flags and other items, and the ink contains an easily sublimable dye that is highly suitable for transfer to polyester by heat treatment. The processing steps are as follows:
(1) Printing step: applying dye ink to an intermediate recording medium by an inkjet printer;
(2) Transfer process: A process of transferring and fixing the dye from the intermediate recording medium into the fiber by heat treatment;
Since commercially available transfer paper can be widely used, no pretreatment of the fabric is required and the washing step is omitted.

Inkjet inks used in the sublimation transfer method are mainly aqueous inks, and sublimation dyes selected from water-insoluble disperse dyes and oil-soluble dyes are dispersed and stabilized in water using a dispersant to form a dye dispersion liquid, which is then made into ink by optimizing physical properties (physical properties) such as particle size, viscosity, surface tension, and pH using a water-soluble organic solvent as a moisturizing agent (anti-drying agent), a surfactant as a surface tension adjuster, and other additives (pH adjusters, antiseptic/anti-fungal agents, defoamers, etc.) (see Patent Document 1). In addition, in inkjet printing, it is important that the ink can be stably discharged from the plate on which the nozzles of the print head are arranged, but with aqueous inks, discharge problems caused by evaporation of water in the ink near the nozzle plate are likely to occur. Examples of the above-mentioned discharge problems include, for example, when an ink composition adheres to and dries on a plate, it cannot be quickly removed by the printer's cleaning operation, causing poor ink discharge (flying curves, etc.) during printing. In order to solve such problems, for example, when using a dye with sublimation properties to express black, black is usually expressed by combining multiple dyes. This is because a single dye is not sufficient to produce a black hue and often has a low concentration, and a combination of multiple dyes allows for good black expression. However, when a fabric is dyed with a black ink that combines multiple dyes with sublimation properties, the black hue expressed on the fabric may appear to be a different color when the fabric is irradiated with light from a light source with a different spectral distribution depending on the type of fabric. For example, even if a good color can be expressed under lighting with little long-wavelength light such as fluorescent lighting, it may appear reddish under sunlight with a lot of long-wavelength light, or conversely, even if a good color can be expressed under sunlight, it may appear bluish under fluorescent lighting. In this way, the characteristic that affects the appearance of the color of an object due to the lighting source is generally called "color rendering," and a black ink with little change in hue due to the influence of color rendering has been desired. Furthermore, ink-jet inks are required to have good ejection properties, and if the dye is unstable or insufficiently dispersed in the ink, the ejection properties in the ink-jet head often become unstable. In particular, black inks, which combine multiple dyes and therefore contain a large number of types and amounts of sublimable dyes, have had problems with ejection stability and storage stability of the ink.

On the other hand, in the sublimation transfer printing method for hydrophobic fibers, sublimation transfer ink is applied (printed) to an intermediate recording medium (specialized transfer paper, etc.) by an inkjet printer, and the ink-applied (printed) surface of the intermediate recording medium is superimposed on the object to be dyed (polyester fiber, etc.), and the sublimation dye is transferred to the object to be dyed by a heat pressing method using a heat pressing roller or a heat press machine. In commercial printing, inkjet printing is becoming faster, and inkjet inks that can be designed to accommodate higher speeds are also required. In addition, as an intermediate recording medium for sublimation transfer ink, inkjet paper with an ink-receiving layer formed on the surface with inorganic fine particles such as silica and a relatively large basis weight so that a large amount of ink can be applied is generally mentioned, but in recent years, transfer paper with a smaller basis weight or transfer paper with a smaller ink-receiving layer has been used, and there is a strong demand for high transfer efficiency and high dyeing density with a small amount of ink. In addition, there is a demand for black ink that does not vary in black hue depending on the sublimation transfer conditions and has a uniform sublimation speed. Patent Document 2 describes a black inkjet ink used in a disperse dye ink for textile printing, characterized in that it contains first to fourth disperse dyes having a maximum absorption wavelength in a specific wavelength range in the ultraviolet-visible spectral absorption of a solution dissolved in a water-soluble organic solvent containing glycol ether and acetone. Although the document mentions an ink that is directly applied to pretreated polyester fibers in a direct printing method, it does not go so far as to discuss technical aspects related to dyes having sublimation properties that can be used in a sublimation transfer method, and does not disclose level dyeing properties or dyeing performance in high-concentration dyeing.

International Publication No. 2005/121263 Patent No. 6191234

As described above, with conventional technology, it was difficult to obtain high-quality dyed products that had high dyeing concentration, excellent color rendering properties, and excellent lightfastness while maintaining stable printability and storage stability of black ink, even when using transfer paper with a small basis weight or transfer paper with a small ink-receiving layer.

The present invention aims to provide a dye dispersion for inkjet textile printing ink that can produce dyed products with excellent color rendering properties in sublimation transfer dyeing using inkjet textile printing, has high sublimation transfer efficiency even when using transfer paper with a small basis weight or a transfer paper with a small ink-receiving layer, and can produce high-quality dyed products with excellent light resistance.

As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that a dye dispersion containing at least one dye represented by the following formula (1), at least one yellow dye, and at least one blue dye solves the above-mentioned problems, and have completed the present invention.
That is, the present invention relates to the following 1) to 10).

1)
A dye dispersion comprising at least one dye represented by the following formula (1), at least one yellow dye, and at least one blue dye:

式（１）中、Ｒ¹、Ｒ²はそれぞれ独立に、水素原子、置換基を有していても良いＣ_1-4アルキル基、アセトキシエチル基、置換基を有していても良い環状アルキル基、又は置換基を有していても良いアリール基を表し、Ｒ³は水素原子、置換基を有していても良いＣ_1-3アルキル基、又はハロゲン原子を表し、Ｒ⁴は水素原子、又はハロゲン原子を表す。

In formula (1), ^R1 and ^R2 each independently represent a hydrogen atom, a _{C1-4 alkyl group which may have a substituent, an acetoxyethyl group, a cyclic alkyl group which may have a substituent, or an aryl group which may have a substituent; R3 represents a hydrogen atom, a C1-3} ^alkyl _group which may have a substituent, or a halogen atom; and ^R4 represents a hydrogen atom or a halogen atom.

2)
The dye dispersion according to 1), further comprising a dispersant.
3)
The dye dispersion according to 1) or 2), wherein, in the above formula (1), R ¹ and R ² each independently represent a C _1-4 alkyl group, and R ³ is any one selected from the group consisting of a hydrogen atom and a C _1-3 alkyl group.
4)
The dye dispersion according to 2) or 3), wherein the dispersant comprises at least one dispersant selected from the group consisting of a styrene-(meth)acrylic copolymer, a formalin condensate of an aromatic sulfonic acid, or a salt thereof.
5)
The dye dispersion according to any one of 1) to 4), further comprising an additive.
6)
5) The dye dispersion liquid according to 5), wherein the additive comprises at least one selected from the group consisting of a water-soluble organic solvent, a preservative, a surfactant, and a pH adjuster.
7)
The dye dispersion according to any one of 1) to 6), further comprising a resin emulsion.
8)
A dye dispersion set comprising the dye dispersion according to any one of 1) to 7) above and a dye dispersion having a hue different from that of the dye dispersion.
9)
A method for printing a hydrophobic fiber, comprising the steps of: depositing droplets of the dye dispersion according to any one of 1) to 7) or the dye dispersion set according to 8) on an intermediate recording medium by an inkjet printer to obtain a recorded image; and then contacting a hydrophobic fiber with the surface of the intermediate recording medium on which the droplets of the dye dispersion are deposited; and heat-treating the hydrophobic fiber to transfer the recorded image to the hydrophobic fiber.
10)
9) A dyed hydrophobic fiber obtained by the method for printing a hydrophobic fiber according to 9).

The present invention provides a dye dispersion for inkjet textile printing ink that can produce dyed products with little change in hue due to the influence of color rendering properties in sublimation transfer dyeing using inkjet textile printing, has high sublimation transfer efficiency, can obtain high-concentration dyed products, and can produce high-quality black dyed products with excellent uniformity and light resistance.

The present invention will be described in detail below. In this specification, including the examples, all "parts" and "%" are by weight unless otherwise specified.

The dye dispersion contains at least one type of the above formula (1).

[Regarding the dye represented by formula (1)]
In the above formula (1), ^R1 and ^R2 each independently represent a hydrogen atom, a _{C1-4 alkyl group which may have a substituent, an acetoxyethyl group, a cyclic alkyl group which may have a substituent, or an aryl group which may have a substituent; R3 represents a hydrogen atom, a C1-3} ^alkyl _group which may have a substituent, or a halogen atom; and ^R4 represents a hydrogen atom or a halogen atom.

Examples of the C _1-4 alkyl group which may have the above-mentioned substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, etc., with an ethyl group being preferred. Examples of the C _1-3 alkyl group which may have the above-mentioned substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, etc., with a methyl group being preferred.

Examples of cyclic alkyl groups which may have the above-mentioned substituents include cyclopentyl groups, cyclohexyl groups, etc.

Examples of aryl groups that may have the above-mentioned substituents include phenyl groups, naphthyl groups, and anthracenyl groups.

Examples of the halogen atom include fluorine, chlorine, bromine, iodine, etc., with bromine being preferred.

The substituents in the above-mentioned C _1-4 alkyl group which may have a substituent, the cyclic alkyl group which may have a substituent, and the aryl group which may have a substituent, and the C _1-3 alkyl group which may have a substituent, are not particularly limited, and examples thereof include a hydroxyl group, a sulfo group, a carboxyl group, a nitro group, a halogen atom, a cyano group, an alkoxy group, and an aryloxy group. The halogen atom may be the same as above. Examples of the alkoxy group include a methoxy group, an ethoxy group, and an n-butoxy group. Examples of the above-mentioned aryloxy group include a phenoxy group and a naphthoxy group.

In the above formula (1), it is preferred that R ¹ and R ² each independently represent a C _1-4 alkyl group, and R ³ is any one selected from the group consisting of a hydrogen atom and a C _1-3 alkyl group.

In the above formula (1), it is more preferable that R ¹ and R ² are each independently an ethyl group, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a bromine atom.

The dye dispersion contains at least one type of yellow dye.

[About yellow dye]
The yellow dye is not particularly limited as long as it is a dye having a yellow hue in general, but is preferably a water-insoluble yellow dye, and among the water-insoluble yellow dyes, it is more preferably a disperse dye-based yellow dye or an oil-soluble dye-based yellow dye, and more preferably a C.I. disperse yellow dye or a C.I. solvent yellow dye. Examples of the C.I. disperse yellow dye include C.I. disperse yellow 3, 7, 8, 23, 39, 51, 54, 60, 64, 71, 79, 82, and 86. Examples of the C.I. solvent yellow dye include C.I. solvent yellow 114 and 163. These dyes can be used alone or in combination. As the dye, it is preferable to use C.I. disperse yellow 7, 54, and C.I. solvent yellow 114, and C.I. It is particularly preferable to use Disperse Yellow 54.

The dye dispersion contains at least one type of blue dye.

[About blue dye]
The blue dye is not particularly limited as long as it is a dye having a blue hue in general, but is preferably a water-insoluble blue dye, and among water-insoluble blue dyes, it is more preferably a disperse dye-based blue dye or an oil-soluble dye-based blue dye, and more preferably a C.I. Disperse Blue-based dye or a C.I. Solvent Blue-based dye. Examples of C.I. Disperse Blue-based dyes include C.I. Disperse Blue 3, 5, 19, 26, 26:1, 35, 55, 56, 58, 60, 64, 64:1, 72, 72:1, 81, 81:1, 91, 95, 108, 131, 141, 145, 334, 359, 360, 336, etc. Examples of C.I. Solvent Blue-based dyes include C.I. Solvent Blue 3, 36, 63, 83, 105, 111, etc. These dyes can be used alone or in combination. The dye is preferably C.I. Disperse Blue 60, 72, 334, 359, 360, more preferably C.I. Disperse Blue 359, 360, and more preferably C.I. Disperse Blue 359 and 360 are used in combination.

The total content ratio of the dye represented by formula (1), the yellow dye, and the blue dye in the dye dispersion can be set as desired, but is usually 1 to 20%, preferably 2 to 15%, and more preferably 3 to 10%, based on mass (mass %) of the total mass of the dye dispersion.

The dye dispersion may further contain a dispersant.

As the dispersant, for example, a styrene-(meth)acrylic copolymer or a formalin condensate of an aromatic sulfonic acid or a salt thereof can be used. The styrene-(meth)acrylic copolymer is a copolymer of a styrene-based monomer and a (meth)acrylic monomer. In this specification, "(meth)acrylic" means "acrylic" and/or "methacrylic". Specific examples of these copolymers include (α-methyl)styrene-acrylic acid copolymer, (α-methyl)styrene-acrylic acid-acrylic acid ester copolymer, (α-methyl)styrene-methacrylic acid copolymer, (α-methyl)styrene-methacrylic acid-acrylic acid ester copolymer, (α-methyl)styrene-(anhydrous)maleic acid copolymer, acrylic acid ester-(anhydrous)maleic acid copolymer, (α-methyl)styrene-acrylic acid ester-(anhydrous)maleic acid copolymer, acrylic acid ester-allylsulfonic acid ester copolymer, acrylic acid ester-styrenesulfonic acid copolymer, (α-methyl)styrene-methacrylic acid sulfonic acid copolymer, polyester-acrylic acid copolymer, polyester-acrylic acid-acrylic acid ester copolymer, polyester-methacrylic acid copolymer, polyester-methacrylic acid-acrylic acid copolymer; and the like. Among these, compounds containing aromatic hydrocarbon groups are preferably styrene. In this specification, (α-methyl)styrene is used to mean α-methylstyrene and styrene. In the dye dispersion, the dispersant preferably contains at least one selected from the group consisting of a styrene-(meth)acrylic copolymer, a formalin condensate of an aromatic sulfonic acid, or a salt thereof. The content of the dispersant in the dye dispersion is usually 1 to 36%, preferably 1 to 30%, more preferably 1 to 20%, and even more preferably 1 to 15%.

Specific examples of the dispersant include Joncryl ^RTM 52J, 57J, 60J, 63J, 70J, JDX-6180, HPD-196, HPD96J, PDX-6137A, 6610, JDX-6500, JDX-6639, PDX-6102B, PDX-6124, 67, 678, 680, 682, 683, and 690 (manufactured by BASF), but are not limited thereto. In this specification, the superscript RTM denotes a registered trademark.

The dispersant in the dye dispersion preferably has a weight average molecular weight of 1,000 to 20,000, more preferably 2,000 to 19,000, and particularly preferably 5,000 to 17,000. The weight average molecular weight of the styrene-acrylic acid copolymer is measured by GPC (gel permeation chromatography). The acid value of the styrene-(meth)acrylic copolymer used as the dispersant is preferably 50 to 250 mgKOH/g, more preferably 100 to 250 mgKOH/g, and particularly preferably 150 to 250 mgKOH/g. If the acid value is too small, the solubility of the resin in water is poor, and especially when the colorant is a dispersible dye, the dispersion stabilization power tends to be poor. If the acid value is too large, the affinity with the aqueous medium becomes strong, and the image after printing tends to bleed easily, which is not preferable. The acid value of the resin represents the number of milligrams of KOH required to neutralize 1 g of the resin, and is measured in accordance with JIS-K 3054. Furthermore, the glass transition temperature of the styrene-(meth)acrylic copolymer used as the dispersant is preferably 45°C to 135°C, more preferably 55°C to 120°C, and particularly preferably 60°C to 110°C.

Specific examples of styrene-(meth)acrylic copolymers, which are preferred dispersants in the above dye dispersion liquid, include Joncryl 67 (weight average molecular weight = 12,500, acid value = 213 mg KOH/g), 678 (weight average molecular weight = 8,500, acid value = 215 mg KOH/g), 682 (weight average molecular weight = 1,700, acid value = 230 mg KOH/g), 683 (weight average molecular weight = 4,900, acid value = 215 mg KOH/g), and 690 (weight average molecular weight = 16,500, acid value = 240 mg KOH/g), with Joncryl 678 being more preferred.

The dye dispersion can be prepared by using two or more types of styrene-acrylic copolymers when dispersing or dissolving the dye.

The dye can be dispersed, for example, by the following method: Styrene-acrylic copolymer is added to a water-soluble organic solvent, and the temperature is raised to 90-120°C to prepare a styrene-acrylic copolymer solution. An alkaline compound and water are then added to the solution, and the temperature is lowered to prepare an emulsified (emulsion or microemulsion) solution. The emulsion solution and the dye are then mixed and dispersed.

The above-mentioned formalin condensate of aromatic sulfonic acid or its salt is an anionic surfactant obtained by a condensation reaction of aromatic sulfonic acid and formalin. Examples of the "salt" include sodium salt, potassium salt, lithium salt, and the like. The above-mentioned formalin condensate of aromatic sulfonic acid or its salt is preferably a formalin condensate of aromatic sulfonic acid or its salt, or a mixture thereof (hereinafter, unless otherwise specified, when the term "formalin condensate of sulfonic acid" is used, it also means "a salt thereof or a mixture thereof"). For example, formalin condensates of creosote oil sulfonic acid, cresol sulfonic acid, phenol sulfonic acid, β-naphthalene sulfonic acid, β-naphthol sulfonic acid, β-naphthalene sulfonic acid and β-naphthol sulfonic acid, benzene sulfonic acid, cresol sulfonic acid, 2-naphthol-6-sulfonic acid, lignin sulfonic acid, and the like can be mentioned. Among these, the formalin condensates of creosote oil sulfonic acid, β-naphthalene sulfonic acid, lignin sulfonic acid, and methylnaphthalene sulfonic acid are preferred. These are available as commercial products under various trade names. Examples of such products include Demol N as a formalin condensate of β-naphthalene sulfonic acid, Demol C as a formalin condensate of creosote oil sulfonic acid, and Demol SN-B as a formalin condensate of special aromatic sulfonic acid (all manufactured by Kao Corporation). Examples of formalin condensates of creosote oil sulfonic acid include the Labelin W series, and examples of formalin condensates of methylnaphthalene sulfonic acid include the Labelin AN series (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). Among these, Demol N, Labelin AN series, and Labelin W series are preferred, Demol N and Labelin W are more preferred, and Labelin W is even more preferred. Examples of lignin sulfonic acid include Vanilex N, Vanilex RN, Vanilex G, and Pearlex DP (all manufactured by Nippon Paper Industries Co., Ltd.). Among these, Vanilex RN, Vanilex N, and Vanilex G are preferred.

The dye dispersion may further contain additives.

Examples of the additives include water-soluble organic solvents, preservatives, surfactants, pH adjusters, chelating agents, rust inhibitors, water-soluble UV absorbers, water-soluble polymer compounds, viscosity adjusters, dye dissolving agents, anti-fading agents, antioxidants, water, etc.

Examples of the water-soluble organic solvent include glycol-based solvents, polyhydric alcohols, pyrrolidones, etc. Examples of glycol-based solvents include glycerin, polyglycerin (#310, #750, #800), diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, heptaglycerin, octaglycerin, nonaglycerin, decaglycerin, undecaglycerin, dodecaglycerin, tridecaglycerin, tetradecaglycerin, and other compounds, and mixtures thereof. Examples of polyhydric alcohols include C2-C6 polyhydric alcohols having 2-3 alcoholic hydroxyl groups, and di- or tri-C2-C3 alkylene glycols or poly-C2-C3 alkylene glycols having 4 or more repeating units and a molecular weight of about 20,000 or less, preferably liquid polyalkylene glycols. Specific examples of these include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, thiodiglycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, glycerin, trimethylolpropane, 1,3-pentanediol, 1,5-pentanediol and other polyhydric alcohols, 2-pyrrolidone, N-methyl-2-pyrrolidone, and the like, and it is preferable to include at least one of glycerin or diglycerin. For convenience, compounds that dissolve in water and act as wetting agents are also included in the water-soluble organic solvent in the present invention, and examples of such compounds include urea, ethylene urea, and sugars. In consideration of storage stability, when the colorant is a disperse dye or an oil-soluble dye, a solvent in which the solubility of the dye is low is preferred, and among these, it is particularly preferred to use glycerin in combination with a solvent other than glycerin (preferably a polyhydric alcohol other than glycerin). The total content of the water-soluble organic solvent in the total mass of the dye dispersion is 5 to 50%, and it is preferable to add 10 to 40%.

Examples of the preservative include organic sulfur, organic nitrogen sulfur, organic halogen, haloarylsulfone, iodopropargyl, N-haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzothiazole, isothiazolinone, dithiol, pyridine oxide, nitropropane, organic tin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, benzyl bromoacetate, inorganic salt, and other compounds. Specific examples of organic halogen compounds include sodium pentachlorophenol, specific examples of pyridine oxide compounds include sodium 2-pyridinethiol-1-oxide, and specific examples of isothiazoline compounds include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride, etc. Specific examples of other antiseptics and fungicides include sodium acetate anhydride, sodium sorbate, or sodium benzoate, and Arch Chemical Company's products under the trade names Proxel ^RTM GXL(S) and Proxel ^RTM XL-2(S).

Examples of the above surfactants include known surfactants such as anionic, cationic, nonionic, and silicone surfactants. Examples of anionic surfactants include alkyl sulfonates, alkyl carboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and their salts, N-acyl methyl taurine salts, alkyl sulfate polyoxyalkyl ether sulfates, alkyl sulfate polyoxyethylene alkyl ether phosphates, rosin acid soap, castor oil sulfate esters, lauryl alcohol sulfate esters, alkyl phenol phosphates, alkyl phosphates, alkylaryl sulfonates, diethyl sulfosuccinates, diethylhexyl cyrsulfosuccinates, and dioctyl sulfosuccinates. Specific examples of commercially available products include, for example, Hitenol LA-10, LA-12, LA-16, Neo Hitenol ECL-30S, and ECL-45, all manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Examples of cationic surfactants include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives. Examples of amphoteric surfactants include lauryl dimethylaminoacetate betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, coconut oil fatty acid amidopropyl dimethylaminoacetate betaine, polyoctyl polyaminoethyl glycine, and imidazoline derivatives. Examples of nonionic surfactants include ether-based surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, and polyoxyethylene alkyl ether; ester-based surfactants such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, and polyoxyethylene stearate; acetylene glycol (alcohol)-based surfactants such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, and 3,5-dimethyl-1-hexyne-3-ol; Surfynol 104, 105, 82, 465, and Olfin STG, both of which are manufactured by Nissin Chemical Industry Co., Ltd.; and polyglycol ether-based surfactants (for example, Tergitol manufactured by SIGMA-ALDRICH Co., Ltd.). 15-S-7, etc.);

Examples of the silicone surfactant include polyether-modified siloxane and polyether-modified polydimethylsiloxane. Specific examples of commercially available products include BYK-347 (polyether-modified siloxane), BYK-345, and BYK-348 (polyether-modified polydimethylsiloxane), all manufactured by BYK-Chemie. Examples of fluorine-based surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chains. Specific examples of commercially available products include Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, Capstone FS-30, FS-31 (manufactured by DuPont); PF-151N, PF-154N (manufactured by Omnova), and the like.

As the pH adjuster, any substance can be used as long as it can control the pH of the solution to a range of approximately 5 to 11 without adversely affecting the dye dispersion liquid to be prepared. Specific examples include alkanolamines such as diethanolamine, triethanolamine, and N-methyldiethanolamine; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; ammonium hydroxide (aqueous ammonia); alkali metal carbonates such as lithium carbonate, sodium carbonate, sodium bicarbonate, and potassium carbonate; alkali metal salts of organic acids such as potassium acetate; and inorganic bases such as sodium silicate and disodium phosphate, with triethanolamine being preferred.

Specific examples of the above chelating agents include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracildiacetate, etc.

Examples of the above-mentioned rust inhibitors include acid sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

Examples of the water-soluble UV absorbers include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

Examples of the water-soluble polymeric compounds include polyvinyl alcohol, cellulose derivatives, polyamines or polyimines.

In addition to water-soluble organic solvents, the viscosity adjusters include water-soluble polymeric compounds, such as polyvinyl alcohol, cellulose derivatives, polyamines, polyimines, etc.

Examples of dye dissolving agents include urea, ε-caprolactam, ethylene carbonate, etc.

The above-mentioned anti-fading agents are used for the purpose of improving the storage stability of images. As the anti-fading agent, various organic and metal complex anti-fading agents can be used. Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Examples of metal complex anti-fading agents include nickel complexes and zinc complexes.

As the antioxidant, for example, various organic and metal complex antioxidants can be used. Examples of the organic antioxidants include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc.

The dye dispersion may contain water. The water to be used is preferably ion-exchanged water, distilled water, or other water with few impurities. The dye dispersion may be subjected to precision filtration using a membrane filter or the like. When the dye dispersion is used for inkjet textile printing ink, precision filtration is preferably performed to prevent nozzle clogging. The pore size of the filter used for precision filtration is usually 1 μm to 0.1 μm, preferably 0.8 μm to 0.1 μm.

In the dye dispersion, it is preferable that the additive comprises at least one selected from the group consisting of a water-soluble organic solvent, a preservative, a surfactant, and a pH adjuster.

The dye dispersion may further contain a resin emulsion.

The above resin emulsions include, for example, emulsions formed from acrylic resins, epoxy resins, urethane resins, polyether resins, polyamide resins, unsaturated polyester resins, phenolic resins, silicone resins, fluororesins, polyvinyl resins (e.g., polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, etc.), alkyd resins, polyester resins, or amino materials (melamine resins, urea resins, urea resins, melamine formaldehyde resins, etc.). These emulsions may also be composed of two or more types of resins. Furthermore, they may be composite resins in which two or more types of resins form a core/shell structure. Among these resin emulsions, urethane resins are preferred for use in the above dye dispersions.

The above urethane resins are often sold in the form of latex (emulsion), and most of them are emulsions with a solid content of 30 to 60%. Specific examples include Permarin UA-150, 200, 310, 368, 3945, and U-coat UX-320 (all manufactured by Sanyo Chemical Industries, Ltd.), Hydran WLS-201, 210, and HW-312B latex (all manufactured by DIC Corporation), and Superflex 150, 170, and 470 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). Among these, examples of polycarbonate-based urethane resins include Permarin UA-310, 3945, and U-coat UX-320. Among these, examples of polyether-based urethane resins include Permarin UA-150, 200, and U-coat UX-340. These urethane resins can be used alone or in combination.

The above urethane resin emulsion preferably has an SP value (solubility parameter) of 8 to 24, more preferably 8 to 17, and particularly preferably 8 to 11. In addition, if the resin in the urethane resin emulsion has acidic groups, and the acidic groups have been neutralized to prepare the emulsion, the SP value of the resin before neutralization is used.

When the urethane resin emulsion has acidic groups such as carboxylic acid, sulfonic acid, or hydroxyl groups, the acidic groups may be alkali-salted. Alkali-salting can be performed, for example, by the following method. One example is a method in which a urethane resin emulsion having acidic groups is added to water and stirred to prepare an aqueous solution, and an alkaline compound is added to the aqueous solution to prepare a liquid with a pH adjusted to 6.0-12.0.

Examples of the alkaline compound include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, hydroxides of alkaline earth metals such as beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide, and triethylamine. Any one of these alkaline compounds may be used alone, or two or more of them may be used in combination.

[Other dyes that may be included in the dye dispersion]
The dye dispersion may contain, as a dye other than the dye represented by the formula (1), the yellow dye, and the blue dye, "other dyes". For example, "Test method for color fastness to dry heat treatment [JIS L 0879:2005] (confirmed in 2010, revised on January 20, 2005, published by the Japan Standards Association)" and "ISO 105-P01, Textiles-Tests for colour fastness-PartP01: Colour fastness to dry heat (excluding pressing)" may be used. In this case, the dyes having a C.I. number may be, for example, the following dyes.

The yellow dyes in the above other dyes include, for example, C.I. Disperse Yellow dyes and C.I. Solvent Yellow dyes other than those exemplified as the yellow dyes above. These dyes can be used alone or in combination.

In the above other dyes, examples of blue dyes include C.I. Disperse Blue dyes and C.I. Solvent Blue dyes other than those exemplified as the blue dyes above. These dyes can be used alone or in combination.

Examples of orange dyes among the other dyes mentioned above include C.I. Disperse Orange 1, 1:1, 5, 7, 11, 13, 20, 23, 25, 25:1, 29, 33, 56, 73, 76, 113, 114, 123, 147; C.I. Solvent Orange 60, 67, etc. These dyes can be used alone or in combination.

Among the above other dyes, examples of brown dyes include C.I. Disperse Brown 1, 3, 22, 26, 27, etc. These dyes can be used alone or in combination.

Among the above other dyes, examples of red dyes include C.I. Disperse Red 4, 11, 50, 53, 55, 55:1, 59, 60, 65, 70, 75, 92, 93, 146, 158, 190, 190:1, 207, 239, 240, 364; C.I. Solvent Red 146; C.I. Bat Red 41; etc. These dyes can be used alone or in combination.

Among the above other dyes, examples of violet dyes include C.I. Disperse Violet 8, 11, 17, 23, 26, 27, 28, 29, 36, 57, and 63. These dyes can be used alone or in combination.

The dye dispersion contains at least one dye represented by the formula (1), one or more yellow dyes, and one or more blue dyes. It is preferable that the dye dispersion contains one dye represented by the formula (1), one yellow dye, and two blue dyes. In the formula (1), R ¹ and R ² are each independently an ethyl group, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a bromine atom. The yellow dye is C.I. Disperse Yellow 54, and the blue dye is C.I. Disperse Blue 60, 334, 359, or 360. In the formula (1), R ¹ and R ² are each independently an ethyl group, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a bromine atom. The yellow dye is C.I. Disperse Yellow 54, and the blue dye is C.I. A combination of Disperse Blue 359 and 360 is even more preferred.

The dyes may be in the form of powder or lumps of dry coloring materials, wet cakes, or slurries, and may contain a small amount of a dispersant such as a surfactant to suppress the aggregation of coloring material particles during or after the synthesis of the coloring material. Commercially available dyes are available in grades for industrial dyeing, resin coloring, ink, toner, and inkjet, and each grade has a different manufacturing method, purity, particle size, etc. In order to suppress the aggregation after pulverization, it is preferable to use coloring materials with smaller particles, and it is also preferable to use coloring materials with as few impurities as possible in terms of the effect on dispersion stability and ink ejection accuracy. Dyes can be used as black coloring materials by blending mainly blue dyes with yellow dyes, orange dyes, and red dyes. In addition, small amounts of other water-insoluble coloring materials may be included within the range of color tone adjustment.

The present invention also includes a dye dispersion set containing the above dye dispersion and a dye dispersion having a different hue from the above dye dispersion.

The dye dispersion may be prepared, for example, by mixing the components. There is no particular restriction on the order in which the components are mixed.

From the viewpoint of high-speed ejection responsiveness, it is preferable that the viscosity of the above-mentioned dye dispersion liquid at 25°C, as measured with an E-type viscometer, is usually about 3 to 20 mPa·s. Furthermore, it is preferable that the surface tension, as measured with the plate method, is usually in the range of 20 to 45 mN/m. It is preferable to adjust each of these values to an appropriate value, taking into consideration the ejection volume, response speed, and flight characteristics of the dye dispersion droplets of the printer being used.

The above-mentioned hydrophobic fiber printing method is roughly divided into two types. The first method is a method called direct printing or direct printing, which is a hydrophobic fiber printing method that includes at least three steps: step A, in which droplets of the dye dispersion are attached to the hydrophobic fiber by an inkjet printer to form image information such as characters and patterns on the hydrophobic fiber; step B, in which the sublimable dye in the droplets of the dye dispersion attached by step A is fixed to the fiber by heat; and step C, in which the unfixed sublimable dye remaining in the fiber is washed off. Step B is generally performed by known steaming or baking. Examples of steaming include a method of fixing the sublimable dye to the fiber by treating the hydrophobic fiber with a high-temperature steamer at usually 170 to 180°C, usually for about 10 minutes; and a method of treating the hydrophobic fiber with a high-pressure steamer at usually 120 to 130°C, usually for about 20 minutes (also called wet heat fixation). Baking (thermosol) is, for example, a method of treating hydrophobic fibers at 190°C to 210°C, usually for about 60 to 120 seconds, to dye the fibers with a sublimation dye (also called dry heat fixation). Step C is a step of washing the obtained fibers with warm water and, if necessary, water. The warm water or water used for washing may contain a surfactant. It is also preferable to dry the washed fibers at 50 to 120°C for 5 to 30 minutes. The second method is a method called sublimation transfer printing, sublimation transfer printing, etc., in which droplets of the dye dispersion or the dye dispersion set are attached to an intermediate recording medium by an inkjet printer to obtain a recorded image such as characters and a pattern, and then the hydrophobic fiber is brought into contact with the surface of the intermediate recording medium to which the droplets of the dye dispersion are attached, and heat treatment is performed to transfer the recorded image such as characters and a pattern recorded on the intermediate recording medium to the hydrophobic fiber. The intermediate recording medium is preferably one in which the sublimable dye in the dye dispersion attached to the intermediate recording medium does not aggregate on its surface, and does not interfere with the sublimation of the dye when the recorded image is transferred to the hydrophobic fiber. One example of such an intermediate recording medium is paper having a dye dispersion receiving layer formed on its surface using inorganic fine particles such as silica, and dedicated paper for inkjet printing can be used. The heat treatment used when transferring the recorded image from the intermediate recording medium to the hydrophobic fiber is usually a dry heat treatment at about 190 to 200°C.

The above-mentioned printing method may further include a fiber pretreatment step for the purpose of preventing bleeding and the like. This pretreatment step includes a step of applying an aqueous solution containing at least one type of sizing agent, an alkaline substance, a reduction inhibitor, and a hydrotropic agent to the fiber before the dye dispersion is applied. In the pretreatment step, it is preferable to use an aqueous solution of a pretreatment agent containing a sizing agent, an alkaline substance, a reduction inhibitor, and a hydrotropic agent as a pretreatment liquid, and impregnate the fiber with the pretreatment liquid. Examples of the sizing agent include natural gums such as guar and locust bean, starches, sodium alginate, seaweed such as funori, plant skins such as pectinic acid, cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, and carboxymethylcellulose, processed starches such as carboxymethyl starch, synthetic pastes such as polyvinyl alcohol and polyacrylic esters, etc. Sodium alginate is preferred.

Examples of the alkaline substance include alkali metal salts of inorganic or organic acids, salts of alkaline earth metals, and compounds that liberate alkali when heated. Inorganic or organic alkali metal hydroxides and alkali metal salts are preferred, and sodium compounds and potassium compounds are included. Specific examples include alkali metal hydroxides such as sodium hydroxide and calcium hydroxide, alkali metal salts of inorganic compounds such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate, sodium dihydrogen phosphate, disodium hydrogen phosphate, and sodium phosphate, and alkali metal salts of organic compounds such as sodium formate and sodium trichloroacetate. Sodium hydrogen carbonate is preferred. The reduction inhibitor is preferably sodium meta-nitrobenzenesulfonate. The hydrotropic agent is, for example, urea, dimethyl urea, and other ureas, and urea is preferred. The sizing agent, alkaline substance, reduction inhibitor, and hydrotropic agent may all be used as a single compound, or multiple compounds may be used in combination. The mixing ratio of each pretreatment agent in the total mass of the pretreatment liquid is, for example, 0.5 to 5% of the sizing agent, 0.5 to 5% of sodium bicarbonate, 0 to 5% of sodium metanitrobenzenesulfonate, 1 to 20% of urea, and the remainder water, all based on mass. The pretreatment agent can be applied to the cellulosic fibers by, for example, a padding method. The squeezing rate of the padding is preferably about 40 to 90%, and more preferably about 60 to 80%.

Specific examples of the hydrophobic fibers include polyester fibers, nylon fibers, triacetate fibers, diacetate fibers, polyamide fibers, and blended fibers using two or more of these fibers. In addition, blended fibers of these with regenerated fibers such as rayon, and natural fibers such as cotton, silk, and wool are also included in the hydrophobic fibers in this specification. Some of these hydrophobic fibers are known to have an ink-receiving layer (bleed prevention layer), and such hydrophobic fibers are also included. The method of forming the ink-receiving layer is a known technology, and fibers having an ink-receiving layer are also commercially available. The material and structure of the ink-receiving layer are not particularly limited, and can be used appropriately depending on the purpose. Dyed hydrophobic fibers obtained by the above-mentioned printing method of hydrophobic fibers are also included in the present invention.

The above dye dispersion liquid can be used in various fields, but is suitable for use as an aqueous writing ink, aqueous printing ink, information recording ink, textile printing, etc., and is particularly preferred for use as an inkjet textile printing ink.

The dye dispersion of the present invention has excellent storage stability without solid precipitation, changes in physical properties, or color changes after long-term storage. In addition, the initial filling property into the inkjet printer head is good, and the continuous printing stability is also good. Furthermore, it is possible to obtain a clear image without bleeding of the image on the paper after printing. In addition to these, the dyed material dyed with the dye dispersion of the present invention has a high dyeing concentration, excellent uniformity and light resistance, and has a high-quality black hue. Furthermore, by using it in combination with dye dispersions containing yellow, orange, magenta, cyan dyes, etc., full-color inkjet printing with excellent fastness and excellent storage stability is possible. Thus, the dye dispersion of the present invention has extremely excellent ejection stability, and is particularly suitable for use as an inkjet printing ink. In particular, when the dye density value is a numerical value of 1.39 or more in the dye density evaluation described below, when no yellow bleeding or staining is observed at the boundary between the dyed portion and the white portion in the dyeability evaluation described below, and when the boundary is clearly reproduced, when the color difference at 60% duty is a numerical value of less than 2.1 in the color rendering evaluation 1 described below, and when the color difference at 60% duty is a numerical value of less than 2.6 in the color rendering evaluation 2 described below, the dye density is high and the black color has excellent dyeability and color rendering properties, and a better black printed material is obtained, the dye dispersion is more excellent.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means parts by mass, and "%" means % by mass, unless otherwise specified.

[Preparation Example 1]
[Preparation of emulsion liquid]
20 parts of Joncryl 678 (manufactured by BASF) were added to 6 parts of 25% sodium hydroxide, 54 parts of ion-exchanged water, and 20 parts of propylene glycol, and the mixture was heated to 90-120° C. and stirred for 5 hours to obtain an emulsion of Joncryl 678.

[Preparation Example 2]
[Preparation of Aqueous Dispersion 1]
A mixture of 30 parts of Kayaset Yellow AG (manufactured by Nippon Kayaku Co., Ltd., C.I. Disperse Yellow 54) as a sublimation dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion were added to the resulting liquid to adjust the dye content to 15%, and then the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC Co., Ltd., filter pore size 0.5 μm) to obtain aqueous dispersion 1.

[Preparation Example 3]
[Preparation of Aqueous Dispersion 2]
A mixture of 30 parts of the following formula (2) as a sublimable dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion were added to the resulting liquid to adjust the dye content to 15%, and then the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC, filter pore size 0.5 μm) to obtain aqueous dispersion 2.

[Preparation Example 4]
[Preparation of Aqueous Dispersion 3]
A mixture of 30 parts of the following formula (3) as a sublimable dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion were added to the resulting liquid to adjust the dye content to 15%, and then the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC, filter pore size 0.5 μm) to obtain aqueous dispersion 3.

[Preparation Example 5]
[Preparation of Aqueous Dispersion 4]
A mixture of 30 parts of C.I. Disperse Blue 359 as a sublimation dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. After adding 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion to the obtained liquid to adjust the dye content to 15%, the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC, filter pore size 0.5 μm) to obtain aqueous dispersion 4.

[Preparation Example 6]
[Preparation of Aqueous Dispersion 5]
A mixture of 30 parts of C.I. Disperse Blue 360 as a sublimation dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. After adding 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion to the obtained liquid to adjust the dye content to 15%, the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC, filter pore size 0.5 μm) to obtain aqueous dispersion 5.

[Preparation Example 7]
[Preparation of Aqueous Dispersion 6]
A mixture of 30 parts of Kayaset Red B (C.I. Disperse Red 60, manufactured by Nippon Kayaku Co., Ltd.) as a sublimation dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion were added to the resulting liquid to adjust the dye content to 15%, and then the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC Co., Ltd., filter pore size 0.5 μm) to obtain aqueous dispersion 6.

[Preparation Example 8]
[Preparation of Aqueous Dispersion 7]
A mixture of 30 parts of C.I. Disperse Brown 27 as a sublimation dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. After adding 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion to the obtained liquid to adjust the dye content to 15%, the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC, filter pore size 0.5 μm) to obtain aqueous dispersion 7.

[Preparation Example 9]
[Preparation of Aqueous Dispersion 8]
A mixture of 30 parts of C.I. Disperse Orange 25 as a sublimation dye, 60 parts of the above Joncryl 678 emulsion, 0.2 parts of Proxel GXL, 0.4 parts of Surfynol 104PG50, and 24 parts of ion-exchanged water was dispersed in a sand mill using 0.2 mm diameter glass beads for about 15 hours under cooling. After adding 60 parts of ion-exchanged water and 30 parts of Joncryl 678 emulsion to the obtained liquid to adjust the dye content to 15%, the mixture was filtered through glass fiber filter paper GC-50 (manufactured by ADVANTEC, filter pore size 0.5 μm) to obtain aqueous dispersion 8.

[Preparation of Aqueous Black Dye Dispersion]
[Example 1]
Four parts of the aqueous dispersion 1 obtained in Preparation Example 2 above, 24 parts of the aqueous dispersion 2 obtained in Preparation Example 3 above, 6 parts of the aqueous dispersion 4 obtained in Preparation Example 5 above, and 11 parts of the aqueous dispersion 5 obtained in Preparation Example 6 above were mixed, and glycerin, Proxel GXL (manufactured by Lonza), Surfynol 465 (manufactured by Nissin Chemical Industry Co., Ltd.), TEA-80 (manufactured by Junsei Chemical Co., Ltd.), and ion-exchanged water were added thereto so as to obtain the compositions shown in Table 1, and the mixture was stirred and then filtered through a 5 μm filter, thereby obtaining an aqueous black dye dispersion of Example 1.

[Example 2]
An aqueous black dye dispersion of Example 2 was obtained in the same manner as in Example 1, except that the aqueous dispersion 3 obtained in Preparation Example 4 was added instead of the aqueous dispersion 2 as shown in Table 1.

[Comparative Example 1]
3 parts of the aqueous dispersion 1 obtained in Preparation Example 2 above, 16 parts of the aqueous dispersion 8 obtained in Preparation Example 9 above, and 16 parts of the aqueous dispersion 5 obtained in Preparation Example 6 above were mixed, and glycerin, Proxel GXL (manufactured by Lonza), Surfynol 465 (manufactured by Nissin Chemical Industry Co., Ltd.), TEA-80 (manufactured by Junsei Chemical Co., Ltd.), and ion-exchanged water were added thereto so as to obtain the compositions shown in Table 1, and the mixture was stirred and then filtered through a 5 μm filter, thereby obtaining an aqueous black dye dispersion of Comparative Example 1.

[Comparative Example 2]
2 parts of the aqueous dispersion 1 obtained in Preparation Example 2 above, 20 parts of the aqueous dispersion 8 obtained in Preparation Example 9 above, and 19 parts of the aqueous dispersion 5 obtained in Preparation Example 6 above were mixed, and glycerin, Proxel GXL (manufactured by Lonza), Surfynol 465 (manufactured by Nissin Chemical Industry Co., Ltd.), TEA-80 (manufactured by Junsei Chemical Co., Ltd.), and ion-exchanged water were added thereto so as to obtain the compositions shown in Table 1, and the mixture was stirred and then filtered through a 5 μm filter, thereby obtaining an aqueous black dye dispersion of Comparative Example 2.

[Comparative Example 3]
3 parts of the aqueous dispersion 1 obtained in Preparation Example 2 above, 20 parts of the aqueous dispersion 7 obtained in Preparation Example 8 above, and 15 parts of the aqueous dispersion 5 obtained in Preparation Example 6 above were mixed, and glycerin, Proxel GXL (manufactured by Lonza), Surfynol 465 (manufactured by Nissin Chemical Industry Co., Ltd.), TEA-80 (manufactured by Junsei Chemical Co., Ltd.), and ion-exchanged water were added thereto so as to obtain the compositions shown in Table 1, and the mixture was stirred and then filtered through a 5 μm filter, thereby obtaining an aqueous black dye dispersion of Comparative Example 3.

[Comparative Example 4]
14 parts of the aqueous dispersion 1 obtained in Preparation Example 2 above, 6 parts of the aqueous dispersion 4 obtained in Preparation Example 5 above, 15 parts of the aqueous dispersion 5 obtained in Preparation Example 6 above, and 23 parts of the aqueous dispersion 6 obtained in Preparation Example 7 above were mixed, and glycerin, Proxel GXL (manufactured by Lonza), Surfynol 465 (manufactured by Nissin Chemical Industry Co., Ltd.), TEA-80 (manufactured by Junsei Chemical Co., Ltd.), and ion-exchanged water were added thereto so as to obtain the compositions shown in Table 1, and the mixture was stirred and then filtered through a 5 μm filter, thereby obtaining an aqueous black dye dispersion of Comparative Example 4.

The following evaluation tests were carried out using each of the aqueous black dye dispersions prepared as described above. The results are shown in Table 2 below.

[Intermediate recording medium printed with aqueous black dye dispersion and sublimation transfer printing using the same]
Each of the prepared aqueous black dye dispersions was filled into an inkjet printer (product name PX-504A, manufactured by EPSON CORPORATION), and a monochrome solid image was printed at 100% duty using TRANSJET EcoII 8385 (95 g/ ^m2 ) as the intermediate recording medium to obtain an intermediate recording medium. The aqueous black dye dispersion-attached surface of each of the obtained intermediate recording media was superimposed on a polyester cloth (Teijin Tropical), and then heat-treated at 200°C x 30 seconds using a tabletop automatic flat press machine (AF-65TEN, manufactured by Asahi Textile Machinery Co., Ltd.) to obtain a dyed product dyed by the sublimation transfer dyeing method. The following evaluations were performed on each of the obtained dyed products.

[Evaluation of dye density]
The 100% duty dyed portion of each of the obtained dyed products was measured using a spectrophotometer "eXact (manufactured by X-rite)" to measure the dyeing density. The color measurement was performed under conditions of a D65 light source, a viewing angle of 2°, and status I. The results are shown in Table 2 below.

[Evaluation of uniformity of sublimation transfer]
The aqueous black dye dispersion-attached surface of each of the intermediate recording media obtained above was superimposed on a polyester cloth (Teijin Tropical), and then heat-treated at 200°C x 20 seconds and 200°C x 60 seconds using a tabletop automatic flat press machine (AF-65TEN manufactured by Asahi Textile Machinery Co., Ltd.) to obtain dyed products dyed by the sublimation transfer dyeing method. The black hue of each of the obtained dyed products was measured using a spectrophotometer "eXact (manufactured by X-rite Co., Ltd.)" under conditions of D65 light source, viewing angle 2°, and status I, and the hue a ^* b ^* was measured. From the obtained a ^* b ^* values, the color difference ΔEab at transfer times of 20 seconds and 60 seconds was calculated using the following (Equation 1). The results are shown in Table 2 below.
ΔEab = [(a ^* ₂₀ seconds - a ^* ₆₀ seconds) ² + (b ^* ₂₀ seconds - b ^* ₆₀ seconds) ² ] ^1/2 (Equation 1)

[Color rendering evaluation 1: Color difference between D65 light source and F2 light source]
Using a spectrophotometer "eXact (manufactured by X-rite)," the hue L ^{*a*b* of each dyed product dyed by the sublimation transfer dyeing method was measured by heat treatment at 200°C for 30 seconds. The color measurement was performed using a viewing angle of 2° and status I conditions, and the L* a * b *} values for the D65 light source and the F2 light source were obtained. The color difference ΔE _D65-F2 was calculated from the obtained L ^* a ^* b ^* values for each light source using ^the following (Formula 2), and evaluated according to the following evaluation criteria.
△E _D65-F2 = [(L ^* _D65 - L ^* _F2 ) ² + (a ^* _D65 - a ^* _F2 ) ² + (b ^* _D65 - b ^* _F2 ) ² ] ^1/2 (Equation 2)
[Evaluation criteria]
S: Color difference ΔE _D65-F2 is less than 1.0.
A: Color difference ΔE _D65-F2 is 1.0 or more and less than 1.4.
B: Color difference ΔE _D65-F2 is 1.4 or more and less than 2.0.
C: Color difference ΔE _D65-F2 is 2.0 or more.

The difference in black hue of the dyed product obtained under a D65 light source and an F2 light source was visually observed and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 2 below.
[Evaluation criteria]
A: The difference in black hue between the D65 light source and the F2 light source is small and barely noticeable.
B: A slight difference in the hue of black is observed between the D65 light source and the F2 light source.
C: There is a large difference in hue of black between the D65 light source and the F2 light source, and it appears bluish under the F2 light source.

[Color rendering evaluation 2: Color difference between D65 light source and A light source]
Using a spectrophotometer "eXact (manufactured by X-rite)," the hue L ^{*a*b* of each dyed product dyed by the sublimation transfer dyeing method was measured by heat treatment at 200°C for 30 seconds. The color measurement was performed using a viewing angle of 2° and status I conditions, and the L* a * b} * values for the D65 light ^source and the A light source were obtained. The color difference ΔE _D65-A ^was calculated from the obtained L ^* a ^* b ^* values for each light source using the following formula (Formula 3), and evaluated according to the following evaluation criteria.
△E _D65-A = [(L ^* _D65 - L ^* _A ) ² + (a ^* _D65 - a ^* _A ) ² + (b ^* _D65 - b ^* _A ) ² ] ^1/2 (Equation 3)
[Evaluation criteria]
S: Color difference ΔE _D65-A is less than 1.0.
A: Color difference ΔE _D65-A is 1.0 or more and less than 1.4.
B: Color difference ΔE _D65-A is 1.4 or more and less than 2.0.
C: Color difference ΔE _D65-A is 2.0 or more.

The difference in hue of the black color of the dyed product obtained under the D65 light source and the A light source was visually observed and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 2 below.
[Evaluation criteria]
A: The difference in black hue between the D65 light source and the A light source is small and barely noticeable.
B: A slight difference in the hue of black is observed between the D65 light source and the A light source.
C: There is a large difference in the hue of black between the D65 light source and the A light source, and it appears reddish under the A light source.

[Light resistance test]
Using a product name: Low-temperature xenon weatherometer XL75 manufactured by Suga Test Instruments Co., Ltd., each dyed product dyed by the sublimation transfer dyeing method was left for 24 hours by heat treatment under the conditions of 100,000 Lux illuminance, humidity 60% RH, and temperature 24°C at 200°C x 30 seconds. After the test, the degree of discoloration of the area irradiated with the xenon lamp of each dyed product was judged using the JIS blue scale for discoloration. The higher the judgment grade, the lower the degree of discoloration and the better the result. The test results are shown in Table 2 below.

As is clear from the results in Table 2 above, the aqueous black dye dispersions of Examples 1 and 2 have superior color rendering properties, high dyeing density, and high-quality black color compared to the aqueous black dye dispersions of Comparative Examples 1 to 4, and are also superior in sublimation transfer uniformity (level dyeing ability) and lightfastness. In addition, the dye dispersions containing at least one dye represented by formula (1) according to the present invention, at least one yellow dye, and at least one blue dye have high transfer efficiency and produce dyed products with high dyeing density and excellent color tone even when using transfer paper with low basis weight or transfer paper with a small ink receiving layer, indicating that they are extremely useful as various recording inks, particularly inkjet textile printing inks.

The dye dispersion of the present invention has high sublimation transfer efficiency and can provide high dyeing density. It can also provide dyed products with excellent color rendering, uniformity, and lightfastness, and can maintain the printability required for various textile printing inks, especially inkjet textile printing inks, making it extremely useful as a black ink for sublimation transfer inkjet textile printing.

Claims (10)

A dye dispersion liquid containing at least one dye represented by the following formula (1), at least one yellow dye, and C.I. Disperse Blue 359 and 360 .
[Chemical formula 1]

(In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a C _1-4 alkyl group which may have a substituent, an acetoxyethyl group, a cyclic alkyl group which may have a substituent, or an aryl group which may have a substituent; R ³ represents a hydrogen atom, a C _1-3 alkyl group which may have a substituent, or a halogen atom; and R ⁴ represents a hydrogen atom or a halogen atom.) The dye dispersion according to claim 1, further comprising a dispersant. 3. The dye dispersion according to claim 1, wherein, in the formula (1), R ¹ and R ² each independently represent a C _1-4 alkyl group, and R ³ is any one selected from the group consisting of a hydrogen atom and a C _1-3 alkyl group. The dye dispersion according to claim 2 or 3, wherein the dispersant contains at least one dispersant selected from the group consisting of styrene-(meth)acrylic copolymer, formalin condensate of aromatic sulfonic acid, or a salt thereof. The dye dispersion according to any one of claims 1 to 4, further comprising an additive. The dye dispersion according to claim 5, wherein the additive includes at least one selected from the group consisting of a water-soluble organic solvent, a preservative, a surfactant, and a pH adjuster. The dye dispersion according to any one of claims 1 to 6 further contains a resin emulsion. A dye dispersion set comprising the dye dispersion according to any one of claims 1 to 7 and a dye dispersion having a hue different from that of the dye dispersion. A method for printing hydrophobic fibers, comprising: depositing droplets of the dye dispersion according to any one of claims 1 to 7, or the dye dispersion set according to claim 8, on an intermediate recording medium by an inkjet printer to obtain a recorded image; then contacting a hydrophobic fiber with the surface of the intermediate recording medium on which the droplets of the dye dispersion have been deposited; and then heat-treating the hydrophobic fiber to transfer the recorded image to the hydrophobic fiber. Dyed hydrophobic fibers obtained by the hydrophobic fiber printing method described in claim 9.