JP2024064996A - Dispersant purification method, colored dispersion, colored dispersion set, recording medium, and hydrophobic fiber printing method - Google Patents

Abstract

[Problem] The present invention aims to provide a method for purifying a dispersant that reduces low odor, a colored dispersion, a colored dispersion set containing the colored dispersion, a recording medium to which the colored dispersion or each colored dispersion contained in the colored dispersion set is attached, and a method for printing hydrophobic fibers using the colored dispersion or colored dispersion set. [Solution] A method for reducing the content of low molecular weight organic compounds in an aromatic sulfonic acid-formalin condensation product dispersant, the method comprising any one of the steps selected from the group consisting of a step of filtering the aromatic sulfonic acid-formalin condensation product dispersant through a membrane, a step of mixing the aromatic sulfonic acid-formalin condensation product dispersant with an adsorbent, and a step of separating and separating the aromatic sulfonic acid-formalin condensation product dispersant using an organic solvent. However, this does not include the case where the aromatic sulfonic acid-formaldehyde condensate-based dispersant is an alkylnaphthalene sulfonic acid-formaldehyde condensate, and in the step of separating the alkylnaphthalene sulfonic acid-formaldehyde condensate using an organic solvent, the low molecular weight organic compound is 1-methylnaphthalene or 2-methylnaphthalene.

Description

The present invention relates to a method for purifying a dispersant, a colored dispersion, a colored dispersion set containing the colored dispersion, a recording medium to which the colored dispersion or each colored dispersion contained in the colored dispersion set is attached, and a method for printing hydrophobic fibers using the colored dispersion or the colored dispersion set.

In recent years, a recording method for plateless printing using inkjet printing has been proposed, and inkjet printing (inkjet printing) is also being used for printing on textiles, including cloth. In comparison with conventional printing methods such as screen printing, inkjet printing has various advantages, including no platemaking required, resource saving, energy saving, and ease of high-resolution expression.

Here, hydrophobic fibers, such as polyester fibers, are generally dyed with water-insoluble colorants. For this reason, it is generally necessary to use a dispersion ink with good performance, such as dispersion stability, in which a water-insoluble colorant is dispersed in water, as an aqueous ink for printing hydrophobic fibers by inkjet printing.

Inkjet printing methods for hydrophobic fibers are broadly divided into direct printing and sublimation transfer. Direct printing is a printing method in which ink is applied (printed) directly onto hydrophobic fibers, and then the dye in the ink is caused to adhere to the hydrophobic fibers by heat treatment such as high-temperature steaming. On the other hand, sublimation transfer is a printing method in which ink is applied (printed) onto an intermediate recording medium (such as dedicated transfer paper), and then the ink-applied surface of the intermediate recording medium is superimposed on the hydrophobic fibers, and the dye is transferred from the intermediate recording medium to the hydrophobic fibers by heat.

The sublimation transfer method is mainly used in the printing of flags and other items, and the ink contains dyes that are easily sublimable and have excellent transferability to hydrophobic fibers through heat treatment. The process includes two steps: (1) printing step: applying the dye ink to an intermediate recording medium using an inkjet printer; and (2) transfer step: transferring and fixing the dye from the intermediate recording medium into the fibers through heat treatment. Since commercially available transfer paper can be widely used, no pretreatment of the fibers is required, and the washing step is omitted.

As ink for the sublimation transfer method, water-based inks in which water-insoluble dyes are dispersed in water are generally used. Such inks are prepared by, for example, adding a water-soluble organic solvent as a moisturizer (anti-drying agent), a surfactant as a surface tension adjuster, and other additives (pH adjusters, antiseptics, antifungals, defoamers, etc.) to a colored dispersion liquid in which a sublimation dye selected from disperse dyes and oil-soluble dyes is dispersed in water with a dispersant, and optimizing the physical properties (physical properties) such as particle size, viscosity, surface tension, and pH.

Dispersants in which sodium naphthalenesulfonate is condensed with formalin (see, for example, Patent Document 1 and Patent Document 2) are known as dispersants for dispersing disperse dyes and the like. When a dispersant in which sodium naphthalenesulfonate alone is condensed with formalin is used, it has strong adsorption to certain disperse dyes, and the dispersion stability of the colored dispersion or ink is satisfactory to a certain extent. On the other hand, it is not satisfactory in terms of odor.

As a dispersant for dispersing disperse dyes, etc., a dispersant obtained by condensing sodium creosote oil sulfonate with formalin (see, for example, Patent Document 3) is also known. Such dispersants use creosote oil containing multiple aromatic compounds as a raw material, so they have strong adsorption to various disperse dyes, and the dispersion stability of the colored dispersion liquid or ink is satisfactory to a certain extent. On the other hand, they are not satisfactory in terms of odor.

Japanese Patent Application Laid-Open No. 9-291235 JP 2003-246954 A International Publication No. 2005/121263

The present invention aims to provide a method for purifying a dispersant that reduces odor, a colored dispersion, a colored dispersion set that includes the colored dispersion, a recording medium to which the colored dispersion or each of the colored dispersions included in the colored dispersion set is attached, and a method for printing hydrophobic fibers using the colored dispersion or the colored dispersion set.

Specific means for solving the above problems include the following embodiments:

[1]
A method for reducing the content of low molecular weight organic compounds in an aromatic sulfonic acid-formaldehyde condensate-based dispersion, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent.
However, this does not include the case where the aromatic sulfonic acid-formalin condensate-based dispersant is an alkylnaphthalenesulfonic acid-formalin condensate, and in the step of liquid-separating the alkylnaphthalenesulfonic acid-formalin condensate using an organic solvent, the low-molecular-weight organic compound is 1-methylnaphthalene or 2-methylnaphthalene.
[2]
The method according to [1], wherein the low molecular weight organic compound is quinoline.
[3]
The method according to [1] or [2], wherein the aromatic sulfonic acid-formalin condensate-based dispersant contains at least one selected from the group consisting of a naphthalene sulfonic acid-formalin condensate or a salt thereof, or a creosote oil sulfonic acid-formalin condensate or a salt thereof.
[4]
The method according to any one of [1] to [3], wherein the aromatic sulfonic acid-formaldehyde condensate-based dispersant contains at least one compound represented by the following formulas (1) to (5):

(In the above formulas (1) to (5), each M is independently any one of a hydrogen atom, a lithium ion, a sodium ion, and a potassium ion.)
[5]
A method for increasing the content of a sulfonic acid compound in an aromatic sulfonic acid-formaldehyde condensate-based dispersant, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent.
[6]
A method for increasing the content of a naphthalenesulfonic acid compound in an aromatic sulfonic acid-formaldehyde condensate-based dispersant, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent.
[7]
The color dispersion contains an aromatic sulfonic acid-formaldehyde condensate-based dispersant, a water-insoluble colorant, and water, and when the aromatic sulfonic acid-formaldehyde condensate-based dispersant in the color dispersion has a solids concentration of 15 mass %, the quinoline content is 1,240 ppm or less.
[8]
The color dispersion according to [7], wherein the water-insoluble colorant is a water-insoluble dye.
[9]
The color dispersion according to [7] or [8], further comprising an ethylene oxide adduct of phytosterol.
[10]
The method according to any one of [1] to [6], comprising a step of mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent.

The present invention provides a method for purifying a dispersant that reduces odor, a colored dispersion, a colored dispersion set that includes the colored dispersion, a recording medium to which the colored dispersion or each colored dispersion included in the colored dispersion set is attached, and a method for printing hydrophobic fibers using the colored dispersion or the colored dispersion set.

Specific embodiments to which the present invention is applied are described in detail below. In this specification, "C.I." stands for Color Index.

<Method of purifying dispersant>
The present invention relates to a method for reducing the content of low molecular weight organic compounds in an aromatic sulfonic acid-formaldehyde condensate-based dispersant, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent.
However, this does not include the case where the aromatic sulfonic acid-formalin condensate-based dispersant is an alkylnaphthalenesulfonic acid-formalin condensate, and in the step of liquid-separating the alkylnaphthalenesulfonic acid-formalin condensate using an organic solvent, the low-molecular-weight organic compound is 1-methylnaphthalene or 2-methylnaphthalene.
In this specification, the aromatic sulfonic acid-formaldehyde condensate-based dispersant may be abbreviated to "formaldehyde condensate of aromatic sulfonic acid" or "dispersant."

The aromatic sulfonic acid-formaldehyde condensate dispersant is a reaction product obtained by a condensation reaction between an aromatic sulfonic acid compound and formalin. In addition, when the aromatic sulfonic acid-formaldehyde condensate dispersant has one or more acidic groups such as sulfo groups or hydroxyl groups, some or all of them may form a salt with an alkali metal such as lithium, sodium, or potassium, an alkaline earth metal such as calcium, or ammonium, etc.

The aromatic sulfonic acid-formalin condensate dispersant can be produced by the methods described in, for example, JP 2009-079010 A, JP 2007-099983 A, JP 2007-099719 A, JP 2016-124932 A, etc. Specifically, it can be obtained by heating naphthalene, methylnaphthalene, dimethylnaphthalene, etc. in sulfuric acid to sulfonate them, and then carrying out a condensation reaction with formalin.

Examples of formalin condensates of aromatic sulfonic acids or their salts include formalin condensates of creosote oil sulfonic acid, cresol sulfonic acid, phenol sulfonic acid, naphthalene sulfonic acid, naphthol sulfonic acid, naphthalene sulfonic acid, alkylnaphthalene sulfonic acid, 1-methylnaphthalene sulfonic acid, 2-methylnaphthalene sulfonic acid, dimethylnaphthalene sulfonic acid, biphenyl sulfonic acid, benzene sulfonic acid, 2-naphthol-6-sulfonic acid, lignin sulfonic acid, and the like, or their salts (sodium salt, potassium salt, lithium salt, and the like). Among these, formalin condensates of creosote oil sulfonic acid, naphthalene sulfonic acid, lignin sulfonic acid, and methylnaphthalene sulfonic acid or their salts are preferred, and formalin condensates of creosote oil sulfonic acid or their salts are particularly preferred.

Formalin condensation products of aromatic sulfonic acids can be obtained commercially. For example, formalin condensation products of naphthalene sulfonic acid include Demol N (manufactured by Kao Corporation). Formalin condensation products of creosote oil sulfonic acid include Demol C (manufactured by Kao Corporation) and Labelin W series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Formalin condensation products of special aromatic sulfonic acids include Demol SN-B (manufactured by Kao Corporation). Formalin condensation products of methylnaphthalene sulfonic acid include Labelin AN series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Among these, Demol N, Labelin AN series, and Labelin W series are preferred, Demol N and Labelin W series are more preferred, and Labelin W series is even more preferred. Lignin sulfonic acid includes Vanilex N, Vanilex RN, Vanilex G, Pearlex DP (all manufactured by Nippon Seishi Co., Ltd.). Examples of formalin condensation of alkylnaphthalenesulfonic acid include Molwet (registered trademark) D-425 powder, Molwet (registered trademark) D-400 powder, Molwet (registered trademark) D-809 powder (all manufactured by Lion-Akzo Co., Ltd.), Polity (registered trademark) N-100K (manufactured by Lion Corporation), Supragil (registered trademark) MNS/90, Supragil (registered trademark) RM/210-EI (all manufactured by Rhodia Nicca Co., Ltd.), etc.

Examples of the low molecular weight organic compound include naphthalene, methylnaphthalene, dimethylnaphthalene, quinoline, isoquinoline, methylquinoline, dimethylquinoline, biphenyl, and diphenylmethane.
The purification method of the aromatic sulfonic acid-formaldehyde condensate dispersant for reducing the content of low molecular weight organic compounds, particularly quinoline, contained in the aromatic sulfonic acid-formaldehyde condensate dispersant is not particularly limited, but may be, for example, extraction such as solid-liquid extraction, liquid-liquid extraction, reflux extraction, Soxhlet extraction, or immersion, stirring, membrane filtration using an RO membrane, or treatment with an adsorbent such as activated carbon, activated clay, ion exchange resin, silica gel, zeolite, or diatomaceous earth. The above-mentioned "liquid-liquid separation" is a separation method in which extraction is performed using an organic solvent, and is generally also called liquid-liquid extraction or liquid-liquid extraction. These means may be used alone or in combination. For example, solid-liquid extraction and liquid-liquid extraction may be combined, or stirring and adsorbent treatment may be combined. In this case, the order between the means may be set arbitrarily according to the purpose such as efficiency.

When performing the above-mentioned liquid-liquid extraction, an organic solvent can be used as the solvent for extraction. The organic solvent may be a hydrophilic organic solvent or a hydrophobic organic solvent. Examples of organic solvents include monohydric, dihydric, or polyhydric alcohols and their aqueous solutions; ketones such as acetone and methyl ethyl ketone; esters such as methyl acetate and ethyl acetate; chain ethers such as diethyl ether; saturated or unsaturated hydrocarbons such as pentane and hexane; aromatic hydrocarbons such as benzene and toluene; halogenated hydrocarbons such as dichloromethane, chloroform, dichloroethane, and carbon tetrachloride; carbon dioxide, supercritical carbon dioxide; edible oils such as rapeseed oil and soybean oil; fats and oils such as diacylglycerol (DAG), medium-chain fatty acid oil, squalane, and squalene; or mixtures thereof. Of the above-mentioned extraction solvents, methyl ethyl ketone is preferred, and ethyl acetate is particularly preferred.

The above extraction conditions are not particularly limited as long as they are conditions that allow sufficient extraction. For example, the amount of solvent used in the extraction is preferably 1 to 100 mL per 1 g of dispersant, and the extraction time may generally be long if the solvent is at a low temperature and short if the solvent is at a high temperature. The extraction operation may be performed two or more times. Preferred extraction conditions include, for example, performing the extraction three times for 1 to 2 hours at 15 to 40°C.

Since organic solvent usually remains in the dispersant layer after the above extraction operation, an additional operation of removing the solvent under reduced pressure may be performed. The degree of reduction in pressure and the time for reduction in pressure are not particularly limited, but for example, the reduction can be performed at 80 mbar for 1 hour. This series of operations allows the dispersant to be purified.

The above-mentioned treatment method using the adsorbent is not particularly limited as long as sufficient adsorption can be performed under the conditions. For example, the amount of adsorbent used is preferably 1 to 100 g per 100 g of dispersant liquid, and the adsorption time may be long if the solvent is low temperature, and short if the solvent is high temperature. The amount of adsorption to the adsorbent is usually high if the solvent is low temperature, and low if the solvent is high temperature. The treatment with the adsorbent may be performed two or more times. Preferred treatment conditions include, for example, performing the treatment at 20°C for 10 minutes to 3 hours. The form of the adsorbent is not particularly limited, and may be powder, pellets, beads, etc. The method of separating the adsorbent from the solvent is not particularly limited as long as separation is possible, such as filtration or centrifugation. A method of filling a column with the adsorbent and circulating the liquid using a pump or the like may also be used.

As a method for purifying an aromatic sulfonic acid-formaldehyde condensation product dispersant that reduces the content of low molecular weight organic compounds, particularly quinoline, contained in the aromatic sulfonic acid-formaldehyde condensation product dispersant, there is provided the following method:
A purification method including a step of contacting the aromatic sulfonic acid-formalin condensation with an organic solvent, or a step of mixing an adsorbent, or a step of passing the liquid through an RO membrane is preferred, a purification method including a step of contacting an organic solvent or a step of mixing an adsorbent is more preferred, and a purification method including a step of contacting an adsorbent is even more preferred. As the adsorbent, for example, ion exchange resin or zeolite is preferred, and zeolite is more preferred. As the zeolite, although not particularly limited, those having a high silica/alumina ratio are preferred. Specifically, the silica/alumina ratio is preferably 2.5 or more, more preferably 5.5 or more, and even more preferably 15 or more. By using zeolite or ion exchange resin as an adsorbent and performing liquid-liquid extraction, excessive reduction of the compound of the following formula such as naphthalene sulfonic acid can be suppressed.

The content of low molecular weight organic compounds in the formalin condensate dispersant of aromatic sulfonic acid, after the low molecular weight organic compound reduction process, is preferably 3300 ppm or less, more preferably 2300 ppm or less, even more preferably 2100 ppm or less, even more preferably 1500 ppm or less, even more preferably 1200 ppm or less, and extremely preferably 1000 ppm or less, when converted to a solids concentration of 40 mass %.

The aromatic sulfonic acid-formaldehyde condensate dispersant preferably contains at least one sulfonic acid compound represented by the following formulas (1) to (5):

(In the above formulas (1) to (5), each M is independently a hydrogen atom, a lithium ion, a sodium ion, or a potassium ion.)

The sulfonic acid compound may be contained in the raw material or may be added later.

The dispersant preferably contains a naphthalene sulfonic acid compound.

The dispersant contains at least one compound represented by the above formula, which can suppress an increase in viscosity and provide a dispersant with excellent storage stability.

A method for increasing the content of a sulfonic acid compound in an aromatic sulfonic acid-formaldehyde condensate-based dispersant, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent.
Any of the steps selected from the group consisting of the step of subjecting the aromatic sulfonic acid-formalin condensate dispersant to membrane filtration, the step of mixing the aromatic sulfonic acid-formalin condensate dispersant with an adsorbent, and the step of subjecting the aromatic sulfonic acid-formalin condensate dispersant to liquid separation using an organic solvent may be the same as those described in the method for reducing the content of low molecular weight organic compounds in the aromatic sulfonic acid-formalin condensate dispersant.

The total mass % of the sulfonic acid compounds contained in the dispersant is preferably 0.5% or more and 99% or less, more preferably 1.0% or more and 95% or less, even more preferably 1.5% or more and 90% or less, even more preferably 3.0% or more and 80% or less, even more preferably 5.0% or more and 70% or less, even more preferably 7.0% or more and 60% or less, and extremely preferably 8.0% or more and 50% or less, after going through the method of increasing the sulfonic acid compound content in the aromatic sulfonic acid formalin condensate dispersant.

A method for increasing the content of a naphthalenesulfonic acid compound in an aromatic sulfonic acid-formaldehyde condensate-based dispersant, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent.
Any of the steps selected from the group consisting of the step of subjecting the aromatic sulfonic acid-formalin condensate dispersant to membrane filtration, the step of mixing the aromatic sulfonic acid-formalin condensate dispersant with an adsorbent, and the step of subjecting the aromatic sulfonic acid-formalin condensate dispersant to liquid separation using an organic solvent may be the same as those described in the method for reducing the content of low molecular weight organic compounds in the aromatic sulfonic acid-formalin condensate dispersant.

The total mass percentage of the naphthalenesulfonic acid compounds contained in the dispersant is preferably 0.01% or more and 99% or less, more preferably 0.1% or more and 95% or less, even more preferably 0.5% or more and 90% or less, even more preferably 1.5% or more and 80% or less, even more preferably 2.0% or more and 70% or less, even more preferably 2.5% or more and 60% or less, and extremely preferably 3.0% or more and 50% or less, after going through the method of increasing the content of the naphthalenesulfonic acid compounds in the aromatic sulfonic acid formalin condensate dispersant.

<Colored Dispersion>
The color dispersion contains an aromatic sulfonic acid-formaldehyde condensate dispersant, a water-insoluble colorant, and water, and when the aromatic sulfonic acid-formaldehyde condensate dispersant in the color dispersion has a solids concentration of 15 mass %, the quinoline content is 1240 ppm or less, preferably 865 ppm or less, more preferably 790 ppm or less, even more preferably 565 ppm or less, particularly preferably 450 ppm or less, and extremely preferably 375 ppm or less.

(Water-insoluble colorant)
The water-insoluble colorant contained in the color dispersion liquid is not particularly limited as long as it can be used as a water-insoluble colorant. For example, known disperse dyes, oil-soluble dyes, carbon black, pigments, etc. can be used, but water-insoluble dyes are preferred, and disperse dyes are most preferred. The water-insoluble colorant may be used alone or in combination. The water-insoluble dye refers to a dye whose solubility in water at 25°C is 3 g/L or less, preferably 2 g/L or less, more preferably 1 g/L or less.
The content of the water-insoluble colorant in the color dispersion is preferably 0.1 to 25% by mass, and more preferably 0.5 to 20% by mass. In this specification, the water-insoluble colorant may be abbreviated to "colorant."

Specific examples of the above water-insoluble colorants include C.I. Disperse Yellow 3, 4, 5, 7, 8, 9, 13, 23, 24, 30, 33, 34, 39, 42, 44, 49, 50, 51, 54, 56, 58, 60, 63, 64, 66, 68, 71, 74, 76, 79, 82, 83, 85, 86, 88, 90, 91, 93, 98, 99, 100, 104, 114, 116, 11 8, 119, 122, 124, 126, 135, 140, 141, 149, 160, 162, 163, 164, 165, 179, 180, 182, 183, 186, 192, 198, 199, 200, 202, 204, 210, 211, 215, 216, 218, 224, 232, 237, C. I. Disperse Orange 1, 1:1, 3, 5, 7, 11, 13, 17, 20, 21, 23, 25, 29, 30, 31, 32, 33, 37, 38, 42, 43, 44, 45, 47, 48, 49, 50, 53, 54, 55, 56, 57, 58, 59, 61, 66, 71, 73, 76, 78, 80, 86, 89, 90, 91, 93, 96, 97, 118, 119, 127, 130, 139, 142, C. I. Disperse Red 1, 4, 5, 7, 11, 12, 13, 15, 17, 27, 43, 44, 50, 52, 53, 54, 55, 55:1, 56, 58, 59, 60, 65, 70, 72, 73, 74, 75, 76, 78, 81, 82, 86, 88, 90, 91, 92, 93, 96, 103, 105, 106, 107, 108, 110, 111, 113, 117, 118, 121, 122, 126, 127, 128, 131, 132, 134, 135, 137, 143, 145, 146, 151, 152, 1 53, 154, 157, 158, 159, 164, 167, 169, 177, 179, 181, 183, 184, 185, 188, 189, 190, 191, 192, 200, 201, 202, 203, 205, 206, 207, 210, 221, 224, 225, 227, 229, 239, 240, 257, 258, 277, 278, 279, 281, 283, 288, 298, 302, 303, 310, 311, 312, 320, 323, 324, 328, 359, 364, C. I. Disperse Violet 1, 4, 8, 11, 17, 23, 26, 27, 28, 29, 31, 33, 35, 36, 38, 40, 43, 46, 48, 50, 51, 52, 56, 57, 59, 61, 63, 69, 77, 97, C. I. Disperse Green 9, C. I. Disperse Brown 1, 2, 4, 9, 13, 19, C. I. Disperse Blue 3, 5, 7, 9, 14, 16, 19, 20, 26, 26:1, 27, 35, 43, 44, 54, 55, 56, 58, 60, 62, 64, 64:1, 71, 72, 72:1, 73, 75, 77, 79, 79:1, 82, 83, 87, 91, 93, 94, 95, 96, 102, 106, 108, 112, 113, 115, 118, 120, 122, 125, 128, 130, 131, 139, 141, 142, 143, 145, 146, 148, 149, 153, 154, 158, 165, 165:1, 165:2, 167, 171, 173, 174, 176, 181, 183, 185, 186, 187, 189, 197, 198, 200, 201, 205, 207, 211, 214, 224, 225, 257, 259, 266, 267, 270, 281, 284, 285, 287, 288, 291, 293, 295, 297, 301, 315, 330, 333, 341, 353, 354, 358, 359, 360, 364, 365, 366, 368, C. I. Disperse Black 1, 3, 10, 24, C. I. Solvent Yellow 114, C.I. I. Solvent Orange 60, 67, C.I. I. Solvent Red 146, C.I. I. Solvent Blue 36, 63, 83, 105, 111, C.I. I. Reactive Yellow 2, 3, 18, 81, 84, 85, 95, 99, 102, C. I. Reactive Orange 5, 9, 12, 13, 35, 45, 99, C. I. Reactive Brown 2, 8, 9, 17, 33, C. I. Reactive Red 3, 3:1, 4, 13, 24, 29, 31, 33, 125, 151, 206, 218, 226, C. I. Reactive Violet 1, 24, C. I. Reactive Blue 2, 5, 10, 13, 14, 15, 15:1, 49, 63, 71, 72, 75, 162, 176, C. I. Reactive Green 5, 8, 19, C. I. Reactive Black 1, 8, 23, 39, C. I. Direct Yellow 2, 3, 4, 9, 10, 11, 12, 13, 15, 16, 50, 66, 73, 84, 86, 87, 88, 89, 91, 110, 127, 128, 129, 130, 132, 138, 139, 141, 142, 145, C. I. Direct Orange 20, 25, 35, 38, 39, 41, C. I. Direct Brown 187, 195, 196, 202, 208, 209, 210, 213, C. I. Direct Red 76, 88, 89, 92, 101, 209, 220, 222, 224, 225, 226, 227, 234, 235, 238, 240, 243, 245, 247, C. I. Direct Blue 52, 55, 57, 76, 80, 84, 86, 87, 92, 102, 105, 106, 108, 110, 112, 197, 199, 200, 202, 205, 220, 231, 233, 235, 237, 238, 240, 245, 248, 250, C. I. Examples of the pigments that may be used include, but are not limited to, C.I. Direct Green 55, 57, 59, 60, 77, 80, 82, 90, C.I. Direct Black 12, 19, 20, 22, 23, 105, 107, 110, 112, 115, 117, 120, 125, 129, 132, 135, 136, etc. Among these, C.I. Disperse Yellow 54; C.I. Disperse Orange 25, 73; C.I. Disperse Red 60, 92; C.I. Disperse Blue 60, 359, 360; and C.I. Solvent Orange 60; are preferred.

The pigments are white or colored powders that are insoluble in water, organic solvents, etc., and include organic and inorganic pigments. In the present invention, the pigments may be either organic or inorganic, but organic pigments are preferred. Specifically, C.I. Pigment Yellow 74, 120, 128, 138, 151, 155, 185, 217, C.I. Pigment Orange 13, 16, 34, 43, C.I. Pigment Red 122, 146, 148, 150, C.I. Pigment Violet 19, 23, C.I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, C.I. Examples include Pigment Green 7, 8, and 36.

As the water-insoluble dye, it is also preferred to use a combination of the dye derivative (hereinafter also referred to as "dye derivative X1") described in WO 2020/204041 and a water-insoluble dye (hereinafter also referred to as "water-insoluble dye Y1").

As the water-insoluble dye Y1, for example, C.I. Disperse Red 60 is preferable.

As the dye derivative X1, for example, C.I. Disperse Red 92, 146; anthraquinone compounds E, F, H, I described in WO 2020/204041; are preferred, and C.I. Disperse Red 92 is more preferred.

Among the combinations of the water-insoluble dye Y1 and the dye derivative X1, a combination of C.I. Disperse Red 60 and at least one dye derivative selected from the group consisting of C.I. Disperse Red 92, 146; and anthraquinone compounds E, F, H, I; is preferred, and a combination of C.I. Disperse Red 60 and C.I. Disperse Red 92 is more preferred.

The blending ratio of the water-insoluble dye Y1 and the dye derivative X1 can be set as desired. The ratio (Y1/X1) of the mass (Y1) of the water-insoluble dye Y1 to the mass (X1) of the dye derivative X1 preferably satisfies the relationship 400>(Y1/X1)>3.125, and more preferably satisfies the relationship 400>(Y1/X1)>19.

It is also a preferred embodiment to use, as a water-insoluble dye, a combination of C.I. Disperse Orange 25 (hereinafter also referred to as "DOr25") and at least one dye selected from the dye represented by formula (1) and the dye represented by formula (2) described in WO 2020/235560 (hereinafter also referred to as "blended dye X2").

As the blended dye X2, for example, C.I. Disperse Orange 49, 62, 71, 73, and 148 are preferable, and C.I. Disperse Orange 73 is more preferable.

The blending ratio of DOr25 and blended dye X2 can be set as desired. When the total content of DOr25 and blended dye X2 is 100 parts by mass, the content of blended dye X2 is preferably less than 10 parts by mass, and more preferably 0.5 to 5 parts by mass.

The colorants may be powdered or lumped dry colorants, wet cakes, or slurries, and may contain a small amount of a dispersant such as a surfactant to suppress the aggregation of colorant particles during or after colorant synthesis. These commercially available colorants are available in grades for industrial dyeing, resin coloring, ink, toner, and inkjet, and each grade has a different manufacturing method, purity, pigment particle size, etc. In order to suppress aggregation after pulverization, colorants with smaller particles are preferred, and those with as few impurities as possible are preferred in terms of the effect on dispersion stability and ink ejection accuracy. As for dyes, a blue dye can be used as a black colorant by blending it with an orange dye and a red dye. In addition, a small amount of other water-insoluble colorants may be included within the range of color tone adjustment.

The above water-insoluble colorants may be mixed together. For example, in preparing black ink, a blue water-insoluble colorant is mainly mixed with an orange water-insoluble colorant and a red water-insoluble colorant to obtain a black color, which can be used as the black water-insoluble colorant. In addition, multiple water-insoluble colorants may be mixed together to fine-tune the color tone of, for example, blue, orange, red, violet, or black to a more preferred color tone.

The above disperse dye is preferably at least one type of disperse dye selected from disperse dyes having a coumarin skeleton, disperse dyes having an azo skeleton, disperse dyes having an anthraquinone skeleton, disperse dyes having a quinophthalone skeleton, and disperse dyes having a thioindigo skeleton, and more preferably at least one type of disperse dye selected from disperse dyes having a coumarin skeleton, disperse dyes having an azo skeleton, and disperse dyes having an anthraquinone skeleton.

In the color dispersion according to this embodiment, when the water-insoluble dye is contained in particulate form, the average particle size is preferably 60 to 200 nm. The average particle size is the particle size calculated by D50 (50% cumulative volume particle size) and is measured by the dynamic light scattering method or the laser diffraction method described in JIS Z8825. Specifically, it can be measured by a particle size distribution meter using the dynamic light scattering method as the measurement principle, such as Microtrack UPA, Nanotrack Wave-UT151, Nanotrack Wave-EX150 (all manufactured by Microtrack Bell Co., Ltd.); ELSZ-2, DLS-8000 (all manufactured by Otsuka Electronics Co., Ltd.); LB-550 (manufactured by Horiba, Ltd.); etc.

(Other ingredients)
The colored dispersion may further contain, as other components, a dispersant other than the above dispersant that can be used in combination (hereinafter, may be abbreviated as a combined dispersant), additives such as a preservative, antifungal agent, or an antifoaming agent, which will be described later.

In the colored dispersion, the mass ratio (total amount of dispersant/disperse dye) of the total amount of dispersant (total of aromatic sulfonic acid formalin condensate dispersant and co-used dispersant) to the disperse dye is preferably in the range of 1/10 to 10/1, more preferably 1/5 to 5/1, and even more preferably 1/5 to 3/1. By being within the above range, the effect of improving the affinity for both the disperse dye and the solvent is appropriately exerted, and the dispersion stability of the disperse dye tends to be further improved even when exposed to high-temperature storage for a long period of time.

Furthermore, the total amount of dispersant in the color dispersion is preferably 1 to 200% by mass, more preferably 10 to 150% by mass, and even more preferably 50 to 120% by mass, based on the total amount of water-insoluble colorant.

(Dispersants that can be used in combination)
The dispersant to be used in combination is not particularly limited as long as it is a substance capable of dispersing the water-insoluble colorant and the dye contained in the inkjet printing ink, other than the above dispersants. Examples of such substances include known dispersants, surfactants, and resin dispersants. In addition, the terms "dispersant to be used in combination" and "surfactant" are simply different names, and may refer to the same substance. As for the type of dispersant to be used in combination, examples of dispersants other than the above-mentioned aromatic sulfonic acid formalin condensate dispersants include styrene-(meth)acrylic copolymers, aromatic sulfonic acid formalin condensates or salts thereof, polyoxyethylene arylphenyl ethers, polyoxyethylene arylphenyl ether sulfates, and polyoxyethylene naphthyl ethers.

Styrene-(meth)acrylic copolymers are copolymers of styrene-based monomers and (meth)acrylic-based monomers. Specific examples of copolymers include (α-methyl)styrene-acrylic acid copolymers, (α-methyl)styrene-acrylic acid-acrylic acid ester copolymers, (α-methyl)styrene-methacrylic acid copolymers, (α-methyl)styrene-methacrylic acid-acrylic acid ester copolymers, (α-methyl)styrene-acrylic acid ester-maleic anhydride copolymers, acrylic acid ester-styrene sulfonic acid copolymers, and (α-methyl)styrene-methacryloylsulfonic acid copolymers. In this specification, "(meth)acrylic" is used to include "acrylic" and "methacrylic". Also, "(α-methyl)styrene" is used to include "α-methylstyrene" and "styrene".

The mass average molecular weight of the styrene-(meth)acrylic copolymer is, for example, preferably 1,000 to 20,000, more preferably 2,000 to 19,000, and even more preferably 5,000 to 17,000. The mass average molecular weight of the styrene-(meth)acrylic copolymer can be measured by GPC (gel permeation chromatography).

The acid value of the styrene-(meth)acrylic copolymer is, for example, preferably 50 to 250 mgKOH/g, more preferably 100 to 250 mgKOH/g, and even more preferably 150 to 250 mgKOH/g. By making the acid value 50 mgKOH/g or more, the solubility in water is improved, and the dispersion stabilization power for water-insoluble dyes tends to be improved. Furthermore, by making the acid value 250 mgKOH/g or less, bleeding of the printed image due to increased affinity with the aqueous medium tends to be suppressed. The acid value of the resin represents the number of mg of KOH required to neutralize 1 g of resin, and can be measured according to JIS-K3054.

The glass transition temperature of the styrene-(meth)acrylic copolymer is, for example, preferably 45 to 135°C, more preferably 55 to 120°C, and even more preferably 60 to 110°C.

Commercially available styrene-(meth)acrylic copolymers include, for example, Joncryl 67, 678, 680, 682, 683, 690, 52J, 57J, 60J, 63J, 70J, JDX-6180, HPD-196, HPD96J, PDX-6137A, 6610, JDX-6500, JDX-6639, PDX-6102B, and PDX-6124 (all manufactured by BASF). Among these, Joncryl 67 (mass average molecular weight: 12500, acid value: 213 mg KOH/g), 678 (mass average molecular weight: 8500, acid value: 215 mg KOH/g), 682 (mass average molecular weight: 1700, acid value: 230 mg KOH/g), 683 (mass average molecular weight: 4900, acid value: 215 mg KOH/g), and 690 (mass average molecular weight: 16500, acid value: 240 mg KOH/g) are preferred, and Joncryl 678 is more preferred.

Examples of formalin condensates of aromatic sulfonic acids or their salts include formalin condensates of creosote oil sulfonic acid, cresol sulfonic acid, phenol sulfonic acid, naphthalene sulfonic acid, naphthol sulfonic acid, naphthalene sulfonic acid, benzene sulfonic acid, cresol sulfonic acid, 2-naphthol-6-sulfonic acid, lignin sulfonic acid, etc. or their salts (sodium salt, potassium salt, lithium salt, etc.). Among these, formalin condensates of creosote oil sulfonic acid, naphthalene sulfonic acid, lignin sulfonic acid, and methylnaphthalene sulfonic acid or their salts are preferred.

Formalin condensation products of aromatic sulfonic acids can be obtained commercially. For example, formalin condensation products of naphthalene sulfonic acid include Demol N (manufactured by Kao Corporation). Formalin condensation products of creosote oil sulfonic acid include Demol C (manufactured by Kao Corporation) and Labelin W series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Formalin condensation products of special aromatic sulfonic acids include Demol SN-B (manufactured by Kao Corporation). Formalin condensation products of methylnaphthalene sulfonic acid include Labelin AN series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Among these, Demol N, Labelin AN series, and Labelin W series are preferred, Demol N and Labelin W series are more preferred, and Labelin W series is even more preferred. For lignin sulfonic acid, Vanilex N, Vanilex RN, Vanilex G, Pearlex DP (all manufactured by Nippon Seishi Co., Ltd.) and the like can be mentioned.

Examples of polyoxyethylene arylphenyl ethers include styrylphenol compounds such as polyoxyethylene monostyrylphenyl ether, polyoxyethylene distyrylphenyl ether, polyoxyethylene tristyrylphenyl ether, and polyoxyethylene tetrastyrylphenyl ether; benzylphenol compounds such as polyoxyethylene monobenzylphenyl ether, polyoxyethylene dibenzylphenyl ether, and polyoxyethylene tribenzylphenyl ether; cumylphenol compounds such as polyoxyethylene cumylphenyl ether; polyoxyethylene naphthylphenyl ether, polyoxyethylene biphenyl ether, and polyoxyethylene phenoxyphenyl ether. Among these, polyoxyethylene distyrylphenyl ether, polyoxyethylene tristyrylphenyl ether, polyoxyethylene dibenzylphenyl ether, polyoxyethylene tribenzylphenyl ether, and polyoxyethylene cumylphenyl ether are preferred.

The number of repetitions of the polyoxyethylene group in the polyoxyethylene aryl phenyl ether is preferably 1 to 30, and more preferably 15 to 30. If the number of repetitions is 1 or more, the compatibility with aqueous solvents and the like tends to be excellent. Also, if the number of repetitions is 30 or less, the viscosity tends not to be too high.

Commercially available polyoxyethylene arylphenyl ethers include, for example, the Noigen EA series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.); Paionin D-6112, Paionin D-6115, Paionin D-6120, Paionin D-6131, Paionin D-6512, Takesurf D-6413, DTD-51, Paionin D-6112, Paionin D-6320 (all manufactured by Takemoto Oil Co., Ltd.); TS-1500, TS-2000, TS-2600, SM-174N (all manufactured by Toho Chemical Industry Co., Ltd.); Emulgen A60, Emulgen A90, Emulgen A500 (all manufactured by Kao Corporation); Emulgen B-66, Newcol CMP series (all manufactured by Nippon Nyukazai Co., Ltd.); and the like.

Examples of polyoxyethylene aryl phenyl ether sulfates include the sulfates of the polyoxyethylene aryl phenyl ethers described above.

Commercially available polyoxyethylene aryl phenyl ether sulfates include, for example, SM-57, SM-130, and SM-210 (all manufactured by Toho Chemical Industry Co., Ltd.).

Commercially available polyoxyethylene naphthyl ethers include, for example, the Noigen EN series (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and Paionin D-7240 (manufactured by Takemoto Yushi Co., Ltd.).

[Phytosterol alkylene oxide adducts, etc.]
The color dispersion according to this embodiment preferably further contains at least one selected from the group consisting of an alkylene oxide adduct of phytosterol, an alkylene oxide adduct of hydrogenated phytosterol, an alkylene oxide adduct of cholestanol, and an alkylene oxide adduct of hydrogenated cholestanol. Hereinafter, phytosterol and hydrogenated phytosterol are also collectively referred to as "phytosterols". In addition, cholestanol and hydrogenated cholestanol are also collectively referred to as "cholestanols".

As the alkylene oxide adduct of phytosterols, for example, a C2-C4 alkylene oxide adduct of phytosterols is preferable, and an ethylene oxide adduct is more preferable. Also, as the alkylene oxide adduct of cholestanols, for example, a C2-C4 alkylene oxide adduct of cholestanol is preferable, and an ethylene oxide adduct is more preferable.

The amount of alkylene oxide (preferably C2-C4 alkylene oxide, more preferably ethylene oxide) added per equivalent of phytosterols or cholestanols is preferably about 10 to 50 equivalents, and the HLB is preferably about 13 to 20.

Commercially available ethylene oxide adducts of phytosterols include, for example, NIKKOL BPS-20 and NIKKOL BPS-30 (both manufactured by Nikko Chemicals Co., Ltd.; ethylene oxide adducts of phytosterols), and NIKKOL BPSH-25 (same manufacturer; ethylene oxide adduct of hydrogenated phytosterols). Commercially available alkylene oxide adducts of cholestanols include, for example, NIKKOL DHC-30 (same manufacturer; ethylene oxide adduct of cholestanol).

When the colored dispersion according to this embodiment contains a dispersant other than the aromatic sulfonic acid-formaldehyde condensate dispersant described above, the content is preferably 50 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the aromatic sulfonic acid-formaldehyde condensate dispersant.

[Additive]
The color dispersion liquid according to the present embodiment may contain additives other than those described above, such as a water-soluble organic solvent, a preservative, a surfactant, a pH adjuster, a chelating agent, a rust inhibitor, a water-soluble ultraviolet absorber, a water-soluble polymer compound, a viscosity adjuster, a dye dissolving agent, an antioxidant, and a resin emulsion.

[Water-soluble organic solvent]
The colored dispersion liquid according to this embodiment preferably further contains glycol ether as a water-soluble organic solvent. Examples of glycol ether include monoalkyl ethers of glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, polyoxyethylene polyoxypropylene glycol, and methoxy glycol. Among these, methyl triglycol (triethylene glycol monomethyl ether), butyl triglycol (triethylene glycol monobutyl ether), butyl diglycol (diethylene glycol monobutyl ether), dipropylene glycol monopropyl ether, and methoxy glycol are preferred, and methoxy glycol is more preferred.

When the color dispersion according to this embodiment contains glycol ether, its content is preferably 0.01 to 90% by mass, and more preferably 0.01 to 85% by mass, based on the total amount of the color dispersion.

Examples of water-soluble organic solvents other than glycol ethers include polyhydric alcohols and pyrrolidones. Examples of polyhydric alcohols include C2-C6 polyhydric alcohols having 2 to 3 alcoholic hydroxyl groups. Examples of pyrrolidones include 2-pyrrolidone and N-methyl-2-pyrrolidone. For convenience, compounds that dissolve in water and act as wetting agents are also included in the water-soluble organic solvents. Examples of such compounds include urea, ethylene urea, and sugars.

Examples of preservatives 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, and inorganic salt compounds. Specific examples of organic halogen compounds include sodium pentachlorophenol. Specific examples of pyridine oxide compounds include sodium 2-pyridinethiol-1-oxide. 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 anhydrous sodium acetate, sodium sorbate, sodium benzoate, and Proxel GXL and Proxel XL-2 (trade names manufactured by Lonza).

Examples of surfactants include known surfactants such as anionic, cationic, amphoteric, nonionic, and fluorine-based 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 taurines, alkyl sulfates, polyoxyalkyl ether sulfates, alkyl sulfates, polyoxyethylene alkyl ether phosphates, rosin acid soaps, castor oil sulfates, lauryl alcohol sulfates, alkyl phenol phosphates, alkyl phosphates, alkylaryl sulfonates, diethyl sulfosuccinates, diethylhexyl sulfosuccinates, dioctyl sulfosuccinates, etc. Examples of commercially available products include Hitenol LA-10, LA-12, LA-16, Neo Hitenol ECL-30S, ECL-45, etc., 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, imidazoline derivatives, etc.

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 manufactured by Air Products Japan Co., Ltd.; and polyglycol ether-based surfactants (for example, Tergitol manufactured by SIGMA-ALDRICH Co., Ltd.). 15-S-7, etc.); etc.

Examples of fluorine-based surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chains, etc. Commercially available products include Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, Capstone FS-30, FS-31 (all manufactured by DuPont); PF-151N, PF-154N (all manufactured by Omnova); etc.

The colored dispersion liquid according to this embodiment preferably contains a polysiloxane compound to improve the ejection response in an inkjet printer and to adjust the surface tension. Examples of polysiloxane compounds include polyether-modified siloxane and polyether-modified polydimethylsiloxane. Commercially available products include BYK-347 (manufactured by BYK-Chemie, polyether-modified siloxane) and BYK-348 (manufactured by BYK-Chemie, polyether-modified polydimethylsiloxane).

When the color dispersion according to this embodiment contains a polysiloxane compound, the content is preferably 0.01 to 3 mass % and more preferably 0.01 to 1.5 mass % relative to the total amount of the color dispersion.

Any substance can be used as the pH adjuster as long as it can control the pH of the color dispersion liquid to a range of approximately 5 to 11 without adversely affecting the color 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. Of these, triethanolamine is preferred.

Examples of chelating agents include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, and sodium uracildiacetate.

Examples of rust inhibitors include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

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

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

Viscosity adjusters include water-soluble organic solvents as well as water-soluble polymeric compounds, such as polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

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

As the antioxidant, various organic and metal complex-based anti-fading agents can be used. Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc. Examples of metal complex-based anti-fading agents include nickel complexes and zinc complexes.

Examples of resin emulsions include emulsions formed from acrylic resins, epoxy resins, urethane resins, polyether resins, polyamide resins, unsaturated polyester resins, phenolic resins, silicone resins, fluororesins, polyvinyl resins (vinyl chloride, vinyl acetate, polyvinyl alcohol, etc.), alkyd resins, polyester resins, amino materials (melamine resins, urea resins, urea resins, melamine formaldehyde resins, etc.), etc. The resin emulsion may contain two or more types of resins. In addition, two or more types of resins may form a core/shell structure. Among resin emulsions, urethane resin emulsions are preferred.

Urethane resin emulsions are commercially available, and most of them are emulsions with a solid content concentration of 30 to 60% by mass. Examples of commercially available urethane resin emulsions 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 and 3945; U-coat UX-320; and the like. Examples of polyether-based urethane resins include Permarin UA-150 and 200; and U-coat UX-340.

The urethane resin in the urethane resin emulsion preferably has an SP value of 8 to 24 (cal/cm ³ ) ^1/2 , more preferably 8 to 17 (cal/cm ³ ) ^1/2 , and even more preferably 8 to 11 (cal/cm ³ ) ^1/2 . The SP value of the urethane resin is calculated by the Fedors method. When the urethane resin has acidic groups and the emulsion is prepared by neutralizing these acidic groups, the SP value of the urethane resin before neutralization is used.

When the urethane resin in the urethane resin emulsion has acidic groups such as carboxy groups, sulfo groups, and hydroxy groups, the acidic groups may be converted to alkaline salts. For example, the acidic groups can be converted to alkaline salts by adding a urethane resin having acidic groups to water and stirring to prepare an aqueous solution, and then adding an alkaline compound to adjust the pH to 6.0 to 12.0. Examples of alkaline compounds 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 the like. The alkaline compounds may be used alone or in combination of two or more.

[water]
The water is preferably water with few impurities, such as ion-exchanged water, distilled water, ultrapure water, etc. Sterilized water may also be used.

The water content is preferably 10 to 99.5% by mass, and more preferably 20 to 90% by mass, based on the total amount of the color dispersion.

[Method of preparing colored dispersion liquid, etc.]
As a method for preparing the colored dispersion according to this embodiment, for example, an aqueous dispersion containing a water-insoluble dye and an aromatic sulfonic acid-formaldehyde condensate-based dispersant is prepared, and other components are further added as necessary.

Methods for preparing the aqueous dispersion include known methods such as stirring and mixing the components that make up the aqueous dispersion using a sand mill (bead mill), roll mill, ball mill, paint shaker, ultrasonic disperser, high-pressure emulsifier, etc. For example, when using a sand mill, first, the components and beads as a dispersion medium are charged into the sand mill. As the beads, glass beads, zirconia beads, etc. with a particle diameter of 0.01 to 1 mm can be used. The amount of beads used is preferably 2 to 6 parts by mass per 1 part by mass of the dispersion target. Next, the sand mill is operated to carry out a dispersion treatment. The dispersion treatment conditions are preferably approximately 1000 to 2000 rpm and 1 to 20 hours. After the dispersion treatment, the beads are removed by filtration or the like to obtain an aqueous dispersion.

The prepared colored dispersion may be subjected to precision filtration using a membrane filter or the like. In particular, when the colored dispersion is used as an ink for inkjet textile printing, it is preferable to perform precision filtration in order to prevent nozzle clogging. The pore size of the filter used for precision filtration is usually 0.1 to 1 μm, and preferably 0.1 to 0.8 μm.

The viscosity of the colored dispersion liquid according to this embodiment at 25°C is preferably about 3 to 20 mPa·s when measured with an E-type viscometer from the viewpoint of high-speed ejection response. The surface tension of the colored dispersion liquid according to this embodiment at 25°C is preferably about 20 to 55 mN/m when measured with a plate method. In practice, the physical property values are adjusted to be appropriate, taking into consideration the ejection volume, response speed, and ink droplet flight characteristics of the inkjet printer used.

The color dispersion according to this embodiment can be used in a variety of fields, but is particularly preferably used as an inkjet printing ink.

The color dispersion liquid according to this embodiment can effectively prevent particles in the color dispersion liquid from agglomerating during storage to increase the average particle size, and can also effectively prevent particles from settling during storage. That is, the color dispersion liquid according to this embodiment can stably maintain the dispersed state of particles in the color dispersion liquid. In addition, the color dispersion liquid according to this embodiment has little odor and is excellent in workability. Furthermore, the color dispersion liquid according to this embodiment has excellent redispersibility after drying compared to a color dispersion liquid containing a styrene-(meth)acrylic copolymer as a dispersant. Therefore, when the color dispersion liquid according to this embodiment is used as an ink, even if aggregated thickeners are generated due to drying of the ink and temporary nozzle clogging of an inkjet printer occurs, the aggregated thickeners are redispersed by the subsequent ink, and the nozzle clogging is easily eliminated.

In addition, the colored products colored using the colored dispersion liquid according to this embodiment are excellent in various fastness properties such as light resistance, weather resistance, moisture resistance, and washability, and are also excellent in color development, color reproducibility, and water resistance.

<Colored dispersion set>
The color dispersion set according to the present embodiment includes the color dispersion according to the present embodiment and at least one other color dispersion having a different hue from that of the color dispersion. The color dispersion according to the present embodiment and the other color dispersion may each include two or more different hues.

<Recording media>
The recording medium according to this embodiment has the colored dispersion according to this embodiment or each of the colored dispersions included in the colored dispersion set according to this embodiment adhered thereto.

Examples of recording media include information transmission sheets such as plain paper, resin-coated paper, paper for inkjet printing, glossy paper, glossy film, and paper for use with electrophotography; fibers, fabrics; glass; metals; ceramics; leather; and color filter substrates. Sheet-shaped recording media are preferably used, but recording media having a three-dimensional shape other than a sheet, such as a sphere or a rectangular solid, may also be used.

A preferred recording medium for inkjet printing is, for example, a medium in which an ink-receiving layer is provided on a substrate such as paper, synthetic paper, or film. The ink-receiving layer is provided by a method of impregnating or coating the substrate with a cationic polymer; a method of coating the substrate surface with inorganic fine particles capable of absorbing the pigment in a coloring dispersion liquid such as porous silica, alumina sol, or special ceramics together with a hydrophilic polymer such as polyvinyl alcohol or polyvinylpyrrolidone; or the like. Recording media provided with such an ink-receiving layer are usually called inkjet paper (film), glossy paper (film), or the like. Among these, the type of inkjet paper in which inorganic fine particles capable of absorbing the pigment in a coloring dispersion liquid such as porous silica, alumina sol, or special ceramics are coated on the substrate surface is said to be susceptible to oxidizing gases in the air such as ozone gas. Representative examples of commercially available specialty paper include Canon Inc.'s Photo Paper Glossy Pro "Platinum Grade" and Photo Paper Glossy Gold; Seiko Epson Corp.'s Photo Paper Crispia (high gloss), Photo Paper (gloss), and Photo Matte Paper; Hewlett-Packard Japan Ltd.'s Advanced Photo Paper (gloss); Brother Corp.'s Premium Plus Glossy Photo Paper; and so on. Of course, plain paper can also be used, and specific examples include Canon Inc.'s PB Paper GF500; Seiko Epson Corp.'s Double-sided High Quality Plain Paper; PPC (Plain Paper Copy) Paper; and so on.

Fibers are also a preferred recording medium for use in inkjet recording. Among fibers, hydrophobic fibers are preferred. Examples of 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 hydrophobic fibers 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. In addition, fiber structures (such as woven fabrics) are also included in the fiber.

<Method of printing hydrophobic fibers>
The hydrophobic fiber printing method according to the present embodiment is a method of printing a hydrophobic fiber using the color dispersion according to the present embodiment or the color dispersion set according to the present embodiment. The hydrophobic fiber printing method is roughly divided into a direct printing method and a sublimation transfer method.

The direct printing method includes a printing process in which droplets of a colored dispersion are deposited on a hydrophobic fiber using an inkjet printer or the like to obtain a recorded image such as a character or a picture, a fixing process in which the water-insoluble dye in the colored dispersion that was deposited on the hydrophobic fiber in the printing process is fixed to the hydrophobic fiber by heat, and a washing process in which any unfixed water-insoluble dye remaining in the hydrophobic fiber is washed away.

The fixing step is generally carried out by known steaming or baking. Examples of steaming include a method in which the hydrophobic fibers are treated with a high-temperature steamer, typically at 170-180°C for about 10 minutes, or with a high-pressure steamer, typically at 120-130°C for about 20 minutes, to fix the water-insoluble dye into the hydrophobic fibers (also called wet heat fixing). Examples of baking (thermosol) include a method in which the hydrophobic fibers are treated with a water-insoluble dye into the hydrophobic fibers (also called dry heat fixing), typically at 190-210°C for about 6-120 seconds.

The washing step is a step in which the obtained fiber is washed with warm water and, if necessary, with water. The warm water or water used for washing may contain a surfactant. It is also preferable to dry the hydrophobic fiber after washing, usually at 50 to 120°C, for 5 to 30 minutes.

On the other hand, the sublimation transfer method includes a printing process in which droplets of the colored dispersion are deposited on an intermediate recording medium using an inkjet printer or the like to obtain a recorded image such as a letter or a picture, and a transfer process in which the recorded image is transferred to the hydrophobic fiber by contacting the surface of the intermediate recording medium to which the colored dispersion has been deposited with hydrophobic fiber and then subjecting it to heat treatment.

The intermediate recording medium is preferably one in which the water-insoluble dye in the attached color dispersion does not aggregate on its surface, and does not interfere with the sublimation of the water-insoluble dye when the recorded image is transferred to the hydrophobic fiber. One example of such an intermediate recording medium is paper with an ink-receiving layer formed on the surface using inorganic fine particles such as silica, and specialized paper for inkjet printing can be used.

The heat treatment used in the transfer process is usually dry heat treatment at around 190 to 200°C.

The hydrophobic fiber printing method according to this embodiment may further include a pretreatment step for the hydrophobic fiber to prevent bleeding, etc. This pretreatment step may include a step of applying an aqueous solution (pretreatment liquid) containing a paste material, an alkaline substance, a reduction inhibitor, and a hydrotropic agent to the hydrophobic fiber before the coloring dispersion liquid is applied.

Examples of adhesives include natural gums such as guar and locust bean; starches; seaweeds such as sodium alginate and funori; plant skins such as pectic acid; cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, and carboxymethylcellulose; processed starches such as carboxymethyl starch; and synthetic adhesives such as polyvinyl alcohol and polyacrylic acid esters; with sodium alginate being preferred.

Examples of alkaline substances include alkali metal salts of inorganic or organic acids; salts of alkaline earth metals; compounds that liberate alkali when heated; and the like, with alkali metal hydroxides and alkali metal salts being preferred. Specific examples include alkali metal hydroxides such as sodium hydroxide and calcium hydroxide; alkali metal salts of inorganic compounds such as sodium carbonate, sodium bicarbonate, potassium carbonate, sodium dihydrogen phosphate, disodium hydrogen phosphate, and sodium phosphate; alkali metal salts of organic compounds such as sodium formate and sodium trichloroacetate; and the like, with sodium bicarbonate being preferred.

As the reduction inhibitor, sodium metanitrobenzenesulfonate is preferred.
Examples of the hydrotropic agent include ureas such as urea and dimethylurea, with urea being preferred.

The adhesive, alkaline substance, reduction inhibitor, and hydrotropic agent may be used alone or in combination of two or more.

The mixing ratio of each component in the pretreatment liquid is, for example, 0.5 to 5% by mass of adhesive, 0.5 to 5% by mass of sodium bicarbonate, 0 to 5% by mass of sodium metanitrobenzenesulfonate, 1 to 20% by mass of urea, and the remainder is water.

One method for applying the pretreatment liquid to hydrophobic fibers is the padding method. The padding squeeze rate is preferably about 40 to 90%, and more preferably about 60 to 80%.

The second method is called sublimation transfer printing, sublimation transfer dyeing, etc. In this method, the ink droplets are attached to an intermediate recording medium by an inkjet printer to obtain an intermediate recording medium on which image information such as characters and patterns are recorded, and then the surface of the intermediate recording medium on which the ink droplets are attached is brought into contact with a material selected from hydrophobic fibers (fibers containing hydrophobic resins), films, and sheets, and heated to cause the water-insoluble colorant (dye) in the ink droplets attached to the intermediate recording medium to be sublimated and transferred to the fiber, thereby dyeing the fiber. As an intermediate recording medium, it is preferable that the water-insoluble colorant (dye) in the ink droplets attached to the intermediate recording medium does not aggregate on its surface and does not interfere with the sublimation of the dye when performing sublimation transfer. One example of such an intermediate recording medium is paper on which an ink-receiving layer is formed on the surface with inorganic fine particles such as silica, and dedicated paper for inkjet recording can be used. As a heating method for transferring a recorded image from the intermediate recording medium to the fiber, a method of dry heat treatment at about 190 to 200°C is usually used.

The intermediate recording medium is not particularly limited, and may be appropriately selected from paper and paperboard varieties and processed products (numbers 6001 to 6284, except for numbers 6235 "oil resistance", 6263 "flute, column", 6273 "pulp molded products", 6276 "carbon paper", 6277 "multi-copy form paper", and 6278 "carbon-backed form paper") listed on pages 28 to 47 of "Paper, Paperboard and Pulp Terminology [JIS P 0001:1998 (confirmed in 2008, revised on March 20, 1998, published by the Japan Standards Association)]"; and cellophane (hereinafter, "paper and paperboard varieties and processed products; and cellophane" are referred to as "paper, etc."). Any of these papers, etc. that can be used for dye sublimation transfer can be used as the intermediate recording medium. As mentioned above, when performing sublimation transfer, heat treatment is usually performed at about 190°C to 210°C. Therefore, among the above intermediate recording media, those that are stable during heat treatment are preferred.

The above inks can be used in a variety of fields, but are suitable for use as water-based writing inks, water-based printing inks, information recording inks, textile printing, etc., and are particularly preferably used as inkjet textile printing inks.

According to the present invention, it is possible to expand the color reproduction range compared to conventional ink-jet printing, without using an unlimited number and variety of dyes as in conventional printing methods using color pastes or the like.
The inkjet printing ink of the present invention can be used without emitting an unpleasant odor during storage and printing. In addition, even if stored for a long period of time, the ink does not cause solid aggregation or precipitation, and has good storage stability. Furthermore, there is very little change in physical properties such as viscosity and average particle size.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified in the examples, "parts," "%," and "ppm" are all based on mass. In addition, the aqueous dispersions and inks in the examples are all included in the above-mentioned colored dispersions.

Example 1
To 100 parts of the sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40%, 6 parts of zeolite HSZ-385HUA (manufactured by Tosoh Corporation, silica/alumina ratio 100) was added and stirred for 3 hours.Then, the mixture was filtered using a Buchner funnel and filter paper, and the solid content was measured.

Example 2
To 100 parts of the sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40%, 6 parts of zeolite HSZ-940HOA (manufactured by Tosoh Corporation, silica/alumina ratio 40) was added and stirred for 3 hours.Then, the mixture was filtered using a Buchner funnel and filter paper, and the solid content was measured.

Example 3
40 parts of ion exchange resin HP-20 was added to 100 parts of sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40%, and the mixture was stirred for 3 hours.Then, the mixture was filtered using a Buchner funnel and filter paper, and the solid content was measured.

Example 4
100 parts of sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40% was passed through an RO membrane (manufactured by Teijin Ltd.) After passing the liquid through 10 cycles, the solid content was measured.

Evaluation of Dispersants
After each purification, the solid content, the amount of quinoline, and the odor of the dispersant were evaluated by the methods described below.

Measurement of Solid Content
The solid content after each purification step was analyzed using a heat-drying moisture meter (MS-70, manufactured by AND Co.).

(Evaluation of components in dispersant)
The amount of quinoline after each purification step was quantitatively analyzed by the internal standard method. Decane was used as the internal standard. After each purification step, the organic components containing quinoline were extracted with chloroform and then measured under the following conditions. The quinoline concentration in Labellin W-40 that was not purified was 3,370 ppm (Comparative Example 1).
-GC measurement conditions-
Apparatus: GC-2014AFSPL (manufactured by Shimadzu)
Column: HP-5 (length 30 m, liquid phase film thickness 0.25 μm, inner diameter 0.32 mm)
Column temperature: 50°C for 3 minutes, increased to 300°C at 10°C per minute Carrier gas: He (flow rate: 1.75 mL/min)
Vaporization chamber temperature: 300°C
Detector temperature: 300°C
Injection volume: 10 μL

<Evaluation>
After the above purification, the following evaluation tests were carried out.
The results are shown in Table 1 below.

<Dispersant odor>
10 mL of each of the purified dispersants and unpurified Labellin W-40 were placed in a 50 mL plastic bottle (Eyeboy wide-mouth bottle, AS ONE Corporation), and the odor of the dispersant was evaluated (by 12 evaluators). The evaluation criteria are as follows: A to E are good evaluations, and F is bad evaluation.
(Evaluation criteria)
A: 11 or more people feel that there is no unpleasant odor. B: 9 to 10 people feel that there is no unpleasant odor. C: 7 to 8 people feel that there is no unpleasant odor. D: 5 to 6 people feel that there is no unpleasant odor. E: 3 to 4 people feel that there is no unpleasant odor. F: 2 or less people feel that there is no unpleasant odor.

Table 1 shows the quinoline content and odor evaluation results when the dispersant has a solid content of 40%.

The results in Table 1 show that the odor was reduced by the purification method of the dispersant of the present invention.

[Examples 5 to 15] Preparation of aqueous dispersions 1 to 4 and 6 to 12 0.2 mm diameter glass beads were added to each of the components shown in Tables 2 to 3 below, and dispersion treatment was carried out for about 15 hours in a sand mill under water cooling. The resulting liquid was filtered through glass fiber filter paper GC-50 (manufactured by Advantec Corporation) to obtain aqueous dispersions each containing 15% water-insoluble colorant (dye). The obtained aqueous dispersions are designated as aqueous dispersions 1 to 4 and 6 to 12, respectively.

Comparative Example 2 Preparation of Aqueous Dispersion 5 0.2 mm diameter glass beads were added to each of the components shown in Table 2 below, and the mixture was dispersed in a sand mill for about 15 hours under water cooling. The resulting solution was filtered through glass fiber filter paper GC-50 (manufactured by Advantec Corporation) to obtain aqueous dispersions each containing 15% water-insoluble colorant (dye). The resulting aqueous dispersion is designated as Aqueous Dispersion 5.

The abbreviations in Tables 2 and 3 above have the following meanings, and the numerical values mean "parts by mass" Labelin W-40: Labelin W-40 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), sodium salt of formalin condensate of creosote oil sulfonic acid BPS-30: Nikkol BPS-30 (manufactured by Nikko Chemicals Co., Ltd.), ethylene oxide adduct of phytosterol Surfynol 104: Surfynol 104 (manufactured by Air Products Japan Co., Ltd.)
Proxel GXL(S): Proxel GXL(S) (manufactured by Lonza)

Evaluation of Aqueous Dispersions
The odor of each of the aqueous dispersions 1 to 12 obtained as described above was evaluated by the evaluation method described below.

<Evaluation>
The following evaluation tests were carried out using each of the aqueous dispersions prepared as described above. The results are shown in Tables 2 and 3.

<Odor of dispersion liquid>
10 mL of each of the aqueous dispersions obtained above was placed in a 50 mL plastic bottle (Eyeboy wide-mouth bottle, AS ONE Corporation) and heated in a thermostatic chamber at 60°C for 1 hour, after which the odor of the dispersion was evaluated (by 12 evaluators). The evaluation criteria are as follows: A to E are good evaluations, and F is bad evaluation.
(Evaluation criteria)
A: 11 or more people feel that there is no unpleasant odor. B: 9 to 10 people feel that there is no unpleasant odor. C: 7 to 8 people feel that there is no unpleasant odor. D: 5 to 6 people feel that there is no unpleasant odor. E: 3 to 4 people feel that there is no unpleasant odor. F: 2 or less people feel that there is no unpleasant odor.

The results in Tables 2 and 3 show that the colored dispersion of the present invention is a dispersion with reduced odor.

Examples 16 to 26 Preparation of Inks 1 to 4 and 6 to 12 The components shown in Tables 4 and 5 below were mixed and stirred for 30 minutes to obtain stock solutions of Inks 1 to 4 and 6 to 12. Each of the resulting inks was filtered through a membrane filter (manufactured by Sartorius) with a pore size of 5.0 μm to prepare test Inks 1 to 4 and 6 to 12 for use in inkjet recording, each of which had a water-insoluble colorant (dye) content of 4%.

Comparative Example 3 Preparation of Ink 5 The components shown in Table 4 below were mixed and stirred for 30 minutes to obtain a stock solution of Ink 5. The resulting ink was filtered through a membrane filter (manufactured by Sartorius) with a pore size of 5.0 μm to prepare test ink 5 for use in inkjet recording, which has a water-insoluble colorant (dye) content of 4%.

The abbreviations in Tables 4 and 5 below have the following meanings, and the numerical values mean "parts by mass" BYK-348: Polyether-modified polydimethylsiloxane (manufactured by BYK Japan Co., Ltd.)
TEA-80: Triethanolamine (manufactured by Oxalis Chemicals Co., Ltd.)
Proxel GXL(S): Proxel GXL(S) (manufactured by Lonza)

<Ink odor>
10 mL of each ink obtained above was placed in a 50 mL plastic bottle (Eyeboy wide-mouth bottle, AS ONE Corporation) and heated in a thermostatic chamber at 60°C for 2 hours, after which the ink odor was evaluated (by 12 evaluators). The evaluation criteria are as follows: A to E are good evaluations, and F is bad evaluation.
(Evaluation criteria)
A: 11 or more people feel that there is no unpleasant odor. B: 9 to 10 people feel that there is no unpleasant odor. C: 7 to 8 people feel that there is no unpleasant odor. D: 5 to 6 people feel that there is no unpleasant odor. E: 3 to 4 people feel that there is no unpleasant odor. F: 2 or less people feel that there is no unpleasant odor.

The results in Tables 4 and 5 above show that the ink of the present invention has a reduced odor.

(Example 27)
To 100 parts of the sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40%, 6 parts of zeolite HSZ-360HUA (manufactured by Tosoh Corporation, silica/alumina ratio 15) was added and stirred for 3 hours.Then, the mixture was filtered using a Buchner funnel and filter paper, and the solid content was measured.

(Example 28)
To 100 parts of the sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40%, 6 parts of zeolite HSZ-320HOA (manufactured by Tosoh Corporation, silica/alumina ratio 5.5) was added and stirred for 3 hours. Thereafter, the mixture was filtered using a Buchner funnel and filter paper, and the solid content was measured.

(Example 29)
100 parts of methyl ethyl ketone was added to 100 parts of sodium salt of creosote oil sulfonic acid formalin condensate with a solid content concentration of 40%, and the mixture was stirred 20 times in a separating funnel. After that, the mixture was left for about 1 hour to separate into an upper layer and a lower layer. The collected lower layer was treated in an evaporator at 80 mba and a water bath temperature of 55° C. for 1 hour. The obtained dispersant was diluted with ion-exchanged water to a dry solid content weight of 40% to obtain a dispersant.

(Example 30)
100 parts of hexane was added to 100 parts of sodium salt of creosote oil sulfonic acid formalin condensate with a solid content concentration of 40%, and the mixture was stirred 20 times in a separatory funnel. The mixture was then left for about 1 hour to separate into an upper layer and a lower layer. The collected lower layer was treated in an evaporator at 80 mba and a water bath temperature of 55°C for 1 hour. The obtained dispersant was diluted with ion-exchanged water to a dry solid content weight of 40% to obtain a dispersant.

(Example 31)
100 parts of ethyl acetate was added to 100 parts of sodium salt of creosote oil sulfonic acid formalin condensate with a solid content concentration of 40%, and the mixture was stirred 20 times in a separatory funnel. The mixture was then left for about 1 hour to separate into an upper layer and a lower layer. The collected lower layer was treated in an evaporator at 80 mba and a water bath temperature of 55°C for 1 hour. The obtained dispersant was diluted with ion-exchanged water to a dry solid content weight of 40% to obtain a dispersant.

(Example 32)
40 parts of ion exchange resin SP850 was added to 100 parts of sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40%, and the mixture was stirred for 3 hours. After that, the mixture was filtered using a Buchner funnel and filter paper, and the solid content was measured.

(Example 33)
40 parts of ion exchange resin SP825L was added to 100 parts of sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40%, and the mixture was stirred for 3 hours. After that, the mixture was filtered using a Buchner funnel and filter paper, and the solid content was measured.

(Example 34)
100 parts of sodium salt of creosote oil sulfonic acid formalin condensate having a solid content concentration of 40% was passed through an RO membrane (manufactured by Teijin Ltd.) After five cycles of passing the liquid, the solid content was measured.

<Dispersant odor>
10 mL of each of the dispersants purified in Examples 27 to 34 above was placed in a 50 mL plastic bottle (Eyeboy wide-mouth bottle, manufactured by AS ONE Corporation), and the odor of the dispersant was evaluated (by 12 evaluators). The evaluation criteria were as follows: A to E are good evaluations, and F is bad evaluation.
(Evaluation criteria)
A: 11 or more people feel that there is no unpleasant odor. B: 9 to 10 people feel that there is no unpleasant odor. C: 7 to 8 people feel that there is no unpleasant odor. D: 5 to 6 people feel that there is no unpleasant odor. E: 3 to 4 people feel that there is no unpleasant odor. F: 2 or less people feel that there is no unpleasant odor.

Table 6 shows the quinoline content and odor evaluation results when the dispersant has a solid content of 40%.

The results in Table 6 show that the odor was reduced by the purification method of the dispersant of the present invention.

[Examples 35 to 49] Preparation of aqueous dispersions 13 to 27 0.2 mm diameter glass beads were added to each component shown in Table 7 below, and dispersion treatment was carried out for about 15 hours in a sand mill under water cooling. The obtained liquid was filtered with glass fiber filter paper GC-50 (manufactured by Advantec Co., Ltd.) to obtain aqueous dispersions each containing 15% water-insoluble colorant (dye). The obtained aqueous dispersions are designated as aqueous dispersions 13 to 27, respectively. The quinoline content of each aqueous dispersion can be calculated from the amount of quinoline contained in the dispersant of Examples 27 to 34.

<Odor of dispersion liquid>
10 mL of each of the aqueous dispersions 13 to 27 obtained above was placed in a 50 mL plastic bottle (Eyeboy wide-mouth bottle, AS ONE Corporation), and heated in a thermostatic chamber at 60°C for 1 hour, after which the odor of the dispersion was evaluated (by 12 evaluators). The evaluation criteria are as follows. A to E are good evaluations, and F is bad evaluation.
(Evaluation criteria)
A: 11 or more people feel that there is no unpleasant odor. B: 9 to 10 people feel that there is no unpleasant odor. C: 7 to 8 people feel that there is no unpleasant odor. D: 5 to 6 people feel that there is no unpleasant odor. E: 3 to 4 people feel that there is no unpleasant odor. F: 2 or less people feel that there is no unpleasant odor.

The results in Table 7 show that the colored dispersion of the present invention is a dispersion with reduced odor.

Examples 50 to 64 Preparation of Inks 13 to 27 The components shown in Table 8 below were mixed and stirred for 30 minutes to obtain stock solutions of Inks 13 to 27. Each of the resulting inks was filtered through a membrane filter (manufactured by Sartorius) with a pore size of 5.0 μm to prepare test Inks 13 to 27 for use in inkjet recording, each of which had a water-insoluble colorant (dye) content of 4%.

The abbreviations in Table 8 below have the following meanings, and the numerical values mean "parts by mass" BYK-348: Polyether-modified polydimethylsiloxane (manufactured by BYK Japan Co., Ltd.)
TEA-80: Triethanolamine (manufactured by Oxalis Chemicals Co., Ltd.)
Proxel GXL(S): Proxel GXL(S) (manufactured by Lonza)

<Ink odor>
10 mL of each of the inks obtained above was placed in a 50 mL plastic bottle (Eyeboy wide-mouth bottle, AS ONE Corporation) and heated in a thermostatic chamber at 60°C for 2 hours, after which the ink odor was evaluated (by 12 evaluators). The evaluation criteria are as follows: A to E are good evaluations, and F is bad evaluation.
(Evaluation criteria)
A: 11 or more people feel that there is no unpleasant odor. B: 9 to 10 people feel that there is no unpleasant odor. C: 7 to 8 people feel that there is no unpleasant odor. D: 5 to 6 people feel that there is no unpleasant odor. E: 3 to 4 people feel that there is no unpleasant odor. F: 2 or less people feel that there is no unpleasant odor.

The results in Table 8 above show that the ink of the present invention has a reduced odor.

Evaluation of Dispersants
The storage stability of the dispersants purified in Examples 1 to 4 and Examples 27 to 34 was evaluated by the evaluation method described below.

(Evaluation of components in dispersant)
The sulfonic acid compound in the dispersant purified above was analyzed by the following procedure: A sample was weighed out so that the solid content was 4 mg, dissolved in 2 mL of water, filtered through a 0.2 μm filter, and measured under the following conditions.
-LC/MS measurement conditions-
Apparatus: Q-Exactive (manufactured by ThermoFisher Scientific)
Column: CORTECS C18
Oven: 40°C
Eluent: 5 mM ammonium acetate aqueous solution: acetonitrile Flow rate: 0.30 mL/min
Injection volume: 1 μL
Detection wavelength: 254 nm

The evaluation criteria for the amount of naphthalenesulfonic acid compound in a dispersant when the solid content of the dispersant is 40% are shown below.
A: 3.0% or more
B: Less than 3.0%, 2.5% or more
C: Less than 2.5%, 2.0% or more
D: Less than 2.0%, 1.5% or more
E: Less than 1.5%, 0.5% or more
F: Less than 0.5%, 0.1% or more
G: Less than 0.1%, 0.01% or more
H: Less than 0.01%

The evaluation criteria for the total amount of sulfonic acid compounds in a dispersant when the solid content of the dispersant is 40% are shown below.
A: 8.0% or more
B: Less than 8.0%, 7.0% or more
C: Less than 7.0%, 5.0% or more
D: Less than 5.0%, 3.0% or more
E: Less than 3.0%, 1.5% or more
F: Less than 1.5%, 1.0% or more
G: Less than 1.0%, 0.5% or more
H: Less than 0.5%

The amount of naphthalenesulfonic acid compounds in the dispersants and the total amount of sulfonic acid compounds in the dispersants for each of the dispersants purified in Examples 1 to 4 and Examples 27 to 34 are shown in Table 9 below.

Evaluation of Colored Dispersions
The storage stability of each of the aqueous dispersions of Examples 5 to 15 and Examples 35 to 49 obtained as described above was evaluated by the evaluation method described below.

[Viscosity change test]
The initial viscosity of the dispersion and that stored at 60°C for 7 days were measured at 25°C and 50 rpm using an E-type viscometer (TV-200, manufactured by Toki Sangyo Co., Ltd.) calibrated with viscometer calibration standard fluid JS10 (manufactured by Nippon Grease Co., Ltd.). The viscosity change rate was calculated from the initial viscosity and the viscosity after storage, and evaluated according to the following criteria. A to E are good evaluations, and F to G are bad evaluations.
-Evaluation criteria-
A: The absolute value of the rate of change is less than 20%. B: The absolute value of the rate of change is 20% or more and less than 25%. C: The absolute value of the rate of change is 25% or more and less than 30%. D: The absolute value of the rate of change is 30% or more and less than 35%. E: The absolute value of the rate of change is 35% or more and less than 40%. F: The absolute value of the rate of change is 40% or more and less than 45%. G: The absolute value of the rate of change is 45% or more.

The evaluation of the viscosity change of each aqueous dispersion of Examples 5 to 15 and Examples 35 to 49 is shown in Table 10 below.

The results in Table 10 above show that the colored dispersion of the present invention has excellent storage stability.

Ink evaluation
The storage stability of each of the inks of Examples 16 to 26 and Examples 50 to 64 obtained as described above was evaluated by the evaluation method described below.

[Viscosity change test]
The initial viscosity of the ink and that after storage at 60°C for 7 days were measured at 25°C and 50 rpm using an E-type viscometer (TV-200, manufactured by Toki Sangyo Co., Ltd.) calibrated with viscometer calibration standard fluid JS10 (manufactured by Nippon Grease Co., Ltd.). The viscosity change value was calculated from the initial viscosity and the viscosity after storage, and evaluated according to the following criteria. A to C are good evaluations, and D is bad evaluation.
-Evaluation criteria-
A: The absolute value of the change is less than 0.4. B: The absolute value of the change is 0.4 or more and less than 0.7. C: The absolute value of the change is 0.7 or more and less than 1.0. D: The absolute value of the change is 1.0% or more.

The evaluation of the viscosity change of each ink in Examples 16 to 26 and Examples 50 to 64 is shown in Table 11 below.

The results in Table 11 above show that the ink of the present invention has excellent storage stability.

[Preparation of dyed fabric]
Using the inks 1 to 27 of each example, a solid pattern was printed on transfer paper, which is an intermediate recording medium, using an inkjet printer EW-452A (manufactured by Seiko Epson Corporation). The ink-bearing surface of the printed transfer paper was superimposed on a polyester cloth (tropical) of the same size, and then heat-treated using a heat press machine (AF-65TEN, Asahi Textile Machinery Co., Ltd.) at 200°C for 60 seconds. Sublimation transfer dyeing was performed from the transfer paper to the polyester cloth, and the desired colors were obtained.

The method for purifying a dispersant of the present invention makes it possible to reduce the odor of the dispersant, and the colored dispersion (dispersion composition for ink) and ink (aqueous ink composition) have low odor and high storage stability, and are particularly useful as an aqueous ink for inkjet printing (especially an inkjet printing ink).

Claims (11)

A method for reducing the content of low molecular weight organic compounds in an aromatic sulfonic acid-formaldehyde condensate-based dispersion, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent.
However, this does not include the case where the aromatic sulfonic acid-formalin condensate-based dispersant is an alkylnaphthalenesulfonic acid-formalin condensate, and in the step of liquid-separating the alkylnaphthalenesulfonic acid-formalin condensate using an organic solvent, the low-molecular-weight organic compound is 1-methylnaphthalene or 2-methylnaphthalene. The method of claim 1, wherein the low molecular weight organic compound is quinoline. The method according to claim 1 or 2, wherein the aromatic sulfonic acid-formaldehyde condensate-based dispersant contains at least one selected from the group consisting of naphthalene sulfonic acid-formaldehyde condensate or its salt, or creosote oil sulfonic acid-formaldehyde condensate or its salt. The method according to claim 1 or 2, wherein the aromatic sulfonic acid-formaldehyde condensate-based dispersant contains at least one compound represented by the following formulas (1) to (5):

(In the above formulas (1) to (5), each M is independently any one of a hydrogen atom, a lithium ion, a sodium ion, and a potassium ion.) A method for increasing the content of a sulfonic acid compound in an aromatic sulfonic acid-formaldehyde condensate-based dispersant, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent. A method for increasing the content of a naphthalenesulfonic acid compound in an aromatic sulfonic acid-formaldehyde condensate-based dispersant, comprising the steps of:
A step of subjecting the aromatic sulfonic acid-formaldehyde condensate-based dispersant to membrane filtration;
mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent;
and a step of separating the aromatic sulfonic acid-formalin condensate-based dispersant using an organic solvent. A colored dispersion containing an aromatic sulfonic acid-formaldehyde condensate dispersant, a water-insoluble colorant, and water, and in which the quinoline content is 1,240 ppm or less when the aromatic sulfonic acid-formaldehyde condensate dispersant in the colored dispersion has a solids concentration of 15 mass %. The color dispersion according to claim 7, wherein the water-insoluble colorant is a water-insoluble dye. The color dispersion according to claim 7 or 8, further comprising an ethylene oxide adduct of phytosterol. The method according to claim 1 or 2, comprising a step of mixing the aromatic sulfonic acid-formaldehyde condensate-based dispersant with an adsorbent. The method of claim 10, wherein the adsorbent is a zeolite.