Water-based inkjet ink for textile printing and method for manufacturing printed materials

Abstract

To provide aqueous inkjet ink for printing which is excellent in wiping property of ink, and suppresses solvent blurring of a printed matter.SOLUTION: Aqueous inkjet ink for printing contains water, a water-soluble organic solvent, amino alcohol, a water-dispersible resin, and a pigment, wherein the solid content is 20 mass% or more with respect to the ink total amount, the water-soluble organic solvent has a boiling point of 250°C or higher, and contains one or more water-soluble organic solvents (A) selected from the group consisting of polyalkylene glycol, a polyalkylene glycol derivative and trihydric alcohol, the water-soluble organic solvent (A) is 1-7 mass% with respect to the total amount of the ink, when the content obtained by excluding the content of the amino alcohol from the total content of the water-soluble organic solvent is 1 pts.mass, the content of the water-soluble organic solvent (A) is 0.110 pts.mass or more, when the total content of the solid content is 1 pts.mass, the content of the amino alcohol is 0.010 pts.mass or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to an aqueous inkjet ink for textile printing and a method for producing printed textiles. [Background technology]

[0002] In addition to screen printing and roller printing, direct inkjet printing, a method for printing images such as letters, pictures, and patterns onto fabrics such as woven, knitted, and nonwoven materials, has recently attracted attention. This method uses computer-aided image processing to print images virtually without plates. Inkjet printing has the advantage of being more versatile than other printing methods because it allows for non-contact printing of images onto fabric. For printing on fabric, water-based inkjet inks are suitable from the standpoint of preventing deterioration of the fabric due to solvents and ensuring environmental safety.

[0003] In textile printing, when using pigments with excellent color development and weather resistance, binders and resins that enhance the adhesion between the pigment and the fabric are used to improve the fixation of the pigment to the fabric. For example, the addition of a binder resin can improve the fixation of the ink image to the fabric and further increase the strength of the ink film.

[0004] When the content of solid components such as pigments and resins is high to fix the ink image to the fabric, the ink may solidify or form a film if left in an open environment. For example, if ink mist adheres to the vicinity of the nozzle when ink is ejected from the inkjet nozzle, the ink adhering to the vicinity of the nozzle may solidify or form a film when exposed to the atmosphere, causing ejection problems. It is possible to wipe off the ink adhering to the vicinity of the nozzle by wiping, but the wiping effect may be reduced if the ink has solidified or formed a film.

[0005] One method to prevent solidification or film formation of water-based inks is to add moisturizing components such as glycerin to the ink to suppress water evaporation. Furthermore, the relationship between the addition of amine compounds to water-based inks and ink solidification or film formation is also being investigated.

[0006] Patent Document 1 proposes using an anionic urethane resin as a fixing resin for water-based ink when printing on a positively charged OHP sheet (overhead projector sheet) to improve the fixation of the ink image. Patent Document 1 discloses the use of polyhydric alcohols such as glycerin in aqueous inks to suppress ink drying.

[0007] Patent Document 2 proposes improving the scratch resistance and maintainability of images by using an aqueous ink containing an anionic urethane resin when printing on glossy paper. Patent Document 2 discloses that when a specific amine compound is included in the aqueous ink in a specific mass ratio relative to the anionic urethane resin, the amine compound remains in the aqueous ink even when water evaporates from the aqueous ink and acts as a counterion of the anionic urethane resin, thereby suppressing an increase in the viscosity of the ink. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2010-053328 [Patent Document 2] Japanese Patent Publication No. 2016-210954 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] As described in Patent Documents 1 and 2, water-based inks applied to OHP sheets, glossy paper, etc., have a low solid content and a relatively high water content. Therefore, the formulation allows for a certain amount of water evaporation from the ink in an open environment. In textile printing, when the total solid content of pigments and resins is high to improve the image density and fixation of the ink image, the system's stability is disrupted when water evaporates from the ink, causing the pigments and resins to aggregate, and further increasing the likelihood of the aggregated pigments and resins becoming fixed.

[0010] In the technology described in Patent Document 1, the proportion of glycerin, a moisturizing component, is increased to suppress ink drying and prevent clogging of inkjet nozzles. However, when a water-based ink containing a large amount of moisturizing components is applied to a cloth, the solvent components become difficult to dry from the cloth, causing the solvent components to spread outside the image area, and solvent bleeding may be observed around the ink image. In the technology described in Patent Document 2, aggregation due to the volatilization of counterions of solid components is prevented by adding an amine compound to the ink. However, when the solid component content in the ink is high and the water content is low, the polarity change of the solvent system when water evaporates from the ink becomes large, which may cause aggregation of pigments, resins, etc.

[0011] One objective of the present invention is to provide an aqueous inkjet ink for textile printing that has excellent wiping properties and suppresses solvent bleeding of printed materials. [Means for solving the problem]

[0012] One aspect of the present invention is an aqueous inkjet ink for textile printing, comprising water, a water-soluble organic solvent, an amino alcohol, a water-dispersible resin, and a pigment, wherein the solid content is 20% by mass or more of the total amount of ink, the water-soluble organic solvent comprises a water-soluble organic solvent (A) having a boiling point of 250°C or higher and being one or more selected from the group consisting of polyalkylene glycol, polyalkylene glycol derivatives, and trihydric alcohols, the water-soluble organic solvent (A) is 1 to 7% by mass of the total amount of ink, the content of the water-soluble organic solvent (A) is 0.110 parts by mass or more when the content of the water-soluble organic solvent excluding the content of the amino alcohol is taken as 1 part by mass, and the content of the amino alcohol is 0.010 parts by mass or more when the total content of solids is taken as 1 part by mass. Another aspect of the present invention is a method for producing a printed fabric, which includes applying the above-described aqueous inkjet ink for printing to a fabric using an inkjet method. [Effects of the Invention]

[0013] According to one embodiment of the present invention, it is possible to provide an aqueous inkjet ink for textile printing that has excellent wiping properties and suppresses solvent bleeding of printed materials. [Modes for carrying out the invention]

[0014] The present invention will be described below using one embodiment. The present invention is not limited by the examples in the following embodiment. The terms and expressions in the following description are not limited by the specific examples in the embodiments described later.

[0015] <Water-based inkjet ink for textile printing> The water-based inkjet ink for printing by resist dyeing according to one embodiment contains water, a water-soluble organic solvent, an amino alcohol, a water-dispersible resin, and a pigment, and the solid content is 20% by mass or more based on the total amount of the ink. The water-soluble organic solvent has a boiling point of 250°C or higher and contains at least one water-soluble organic solvent (A) selected from the group consisting of a polyalkylene glycol, a polyalkylene glycol derivative, and a trivalent alcohol. The water-soluble organic solvent (A) is 1 to 7% by mass based on the total amount of the ink. When the content excluding the content of the amino alcohol from the total content of the water-soluble organic solvent is 1 part by mass, the content of the water-soluble organic solvent (A) is 0.110 part by mass or more, and when the total content of the solid content is 1 part by mass, the content of the amino alcohol is 0.010 part by mass or more. According to this, it is possible to provide a water-based inkjet ink for printing by resist dyeing that is excellent in the wiping property of the ink and suppresses solvent bleeding of the printed matter. In the following description, the water-based inkjet ink for printing by resist dyeing may be simply referred to as a water-based ink or an ink.

[0016] In the water-based ink, particulate substances such as pigments and resin particles are preferably in a dispersed state by electrostatic repulsive force. Counterions are contained to assist the electrostatic repulsive force of the particulate substances in the water-based ink. Since this counterion is generally incorporated into the water-based ink as an ionic compound having a low boiling point, when the water-based ink is left in an open-air environment, the low-boiling ionic compound volatilizes from the ink together with the water. When the ionic compound volatilizes and the counterions in the ink decrease, the electrostatic repulsive force between the particulate substances becomes weak, and the particulate substances tend to aggregate. When the solid content is 20% by mass or more based on the total amount of the ink, it is desirable that the counterions are sufficiently contained in the water-based ink in order to obtain the auxiliary effect of the electrostatic repulsive force. Since amino alcohols are compounds with relatively high boiling points, when amino alcohols are contained in aqueous inks, volatilization from the inks can be suppressed even in an open and standing environment. Since the amino group site of amino alcohols exhibits cationicity, it can act as a counter ion for particulate matter in aqueous inks and assist the electrostatic repulsive force of the particulate matter. Also, since amino alcohols are organic substances, they have a high affinity with water-soluble organic solvents, and thus tend to act as counter ions for particulate matter in aqueous inks. Thus, amino alcohols can assist the electrostatic repulsive force of particulate matter and suppress the aggregation of particulate matter. In a state where particulate matter is likely to aggregate due to a decrease in counter ions, when the aqueous ink is ejected from the inkjet nozzle and ink mist adheres near the nozzle discharge port, the particulate matter of the ink may adhere near the nozzle discharge port, causing poor discharge from the nozzle. Furthermore, the particulate matter adhering near the nozzle discharge port becomes difficult to remove by the wiping operation of the printing apparatus, which may cause a decrease in the wiping property of the ink. When the wiping property decreases, it becomes difficult to improve poor discharge, and furthermore, the lifespan of members such as the wiper may be shortened, and the maintainability of the printing apparatus may decrease.

[0017] The water-soluble organic solvent (A) contained in the aqueous ink has a boiling point of 250°C or higher and is one or more selected from the group consisting of polyalkylene glycols, polyalkylene glycol derivatives, and trivalent alcohols. Therefore, it exhibits high boiling point and high polarity, is difficult to volatilize from the aqueous ink, and furthermore exhibits moisture retention and can suppress the volatilization of moisture from the aqueous ink. On the other hand, when the aqueous ink is applied to the cloth, the water-soluble organic solvent (A) is difficult to volatilize from the printed matter and suppresses the volatilization of moisture. Therefore, it may contribute to the occurrence of solvent bleeding in the printed matter. Solvent bleeding is a phenomenon in which the solvent component seeps out from the area where the ink is applied in the printed matter, and discoloration of the base material by the solvent is observed around the ink image. By specifying the content of the water-soluble organic solvent (A) relative to the total amount of ink, it is possible to suppress the evaporation of water and to suppress the bleeding of the solvent in the printed material.

[0018] When the content of water-soluble organic solvent (A) is set to 0.110 parts by mass or more, excluding the content of amino alcohol from the total content of water-soluble organic solvent, the mass proportion of high-boiling-point and highly polar water-soluble organic solvent (A) in the solvent system can be increased. Since water-soluble organic solvent (A) exhibits a high boiling point, it does not easily evaporate from water-based ink even in an open environment. Therefore, even if water evaporates and decreases, the decrease in water-soluble organic solvent (A) is suppressed, and the solvent system can be maintained at a high polarity. When the polarity of the solvent system decreases, poor dispersion of particulate matter, especially hydrophilic particulate matter, can occur. Therefore, by maintaining a high polarity of the solvent system, aggregation of particulate matter is suppressed, and a decrease in the wiping properties of the ink can be prevented.

[0019] Furthermore, since amino alcohol acts as a counterion for particulate matter in water-based ink, by specifying the mass ratio of amino alcohol to the solid content containing particulate matter, it is possible to sufficiently maintain the electrostatic repulsion force of particulate matter in water-based ink, suppress aggregation of particulate matter, and prevent a decrease in the wiping properties of the ink.

[0020] Water-based inks contain water, a water-soluble organic solvent, amino alcohol, a water-dispersible resin, and a pigment, with a solid content of 20% by mass or more of the total ink volume. The solid content of water-based ink is the total amount of components excluding volatile components. Examples of solid content in water-based inks include pigments and water-dispersible resins, as well as non-volatile components from among optional components such as pigment dispersants, surfactants, and crosslinking agents. The solid content of water-based inks can be determined by thermal analysis such as TG-DTA (differential thermogravimetric analysis). Specifically, it is the total mass of components remaining when the ink is heated to 500°C under a nitrogen atmosphere using RIGAKU's "Thermo plus EV02" (product name).

[0021] The solid content being 20% ​​by mass or more of the total amount of aqueous ink increases the pigment concentration in the ink, thereby increasing the image density of the printed material. Furthermore, if resin particles are included as solid content, a resin coating is formed on the printed material, further improving the fixation of the ink image. In addition, the formation of a resin coating on the printed material increases the strength of the ink image coating, further improving the abrasion resistance and fastness of the printed material. In one embodiment, since the electrostatic repulsion force of particulate matter such as pigment can be sufficiently maintained, a decrease in the wiping properties of the ink can be prevented even if the solid content is 23% by mass or more, or 25% by mass or more, of the total amount of aqueous ink. While not particularly limited, from the viewpoint of preventing the ink from becoming highly viscous and improving the ejection performance, the solid content is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, relative to the total amount of aqueous ink. Within these ranges, the solid content can be appropriately adjusted while suppressing the aggregation of solids including pigments and resin particles, taking into account the image density, application, texture, etc., of the printed material. For example, the solid content may be 20-40% by mass, 23-35% by mass, or 25-30% by mass relative to the total amount of ink.

[0022] Water-based inks contain a water-soluble organic solvent (A). The water-soluble organic solvent (A) has a boiling point of 250°C or higher and may be one or more selected from the group consisting of polyalkylene glycols, polyalkylene glycol derivatives, and trihydric alcohols. The water-soluble organic solvent (A) is included in an amount of 1% by mass or more relative to the total amount of ink, thereby ensuring sufficient moisture retention of the water-based ink and suppressing water evaporation in open environments. Since this prevents a decrease in the polarity of the water-based ink due to water loss, the aggregation of particulate matter is suppressed, preventing a decrease in the ink's wiping properties. Furthermore, by suppressing water evaporation from the water-based ink, the thickening of the ink is suppressed, thus improving the ink's wiping properties. More preferably, the water-soluble organic solvent (A) is 3% by mass or more, and even more preferably 4% by mass or more, relative to the total amount of ink. The water-soluble organic solvent (A) is included in an amount of 7% by mass or less relative to the total amount of ink, thereby promoting the evaporation of water and the water-soluble organic solvent on the surface of the printed material and preventing solvent bleeding of the printed material. From the viewpoint of further preventing solvent bleeding of the printed material, the amount of water-soluble organic solvent (A) may be 6% by mass or less, or 5% by mass or less, relative to the total amount of ink. For example, the water-soluble organic solvent (A) may be 1-7% by mass, 3-6% by mass, or 4-7% by mass relative to the total amount of ink.

[0023] When the content of the water-soluble organic solvent excluding the amino alcohol content is taken as 1 part by mass from the total content of the water-soluble organic solvent, the content of the water-soluble organic solvent (A) is preferably 0.110 parts by mass or more, more preferably 0.120 parts by mass or more, even more preferably 0.130 parts by mass or more, and even more preferably 0.150 parts by mass or more. Within these ranges, aggregation of particulate matter in the aqueous ink can be suppressed, and a decrease in the wiping properties of the ink can be prevented. When the content of the water-soluble organic solvent (A) is taken as 1 part by mass from the total content of the water-soluble organic solvent excluding the content of amino alcohol, the content of the water-soluble organic solvent (A) is not particularly limited, but is preferably 0.650 parts by mass or less, more preferably 0.550 parts by mass or more, and even more preferably 0.450 parts by mass or less. Within these ranges, the occurrence of solvent bleeding in the printed material can be further prevented. From the viewpoint of further preventing solvent bleeding in the printed material, the mass ratio of this water-soluble organic solvent (A) is more preferably 0.400 parts by mass or less, or 0.300 parts by mass or less. For example, when the content of the water-soluble organic solvent excluding the amino alcohol content is taken as 1 part by mass, the content of the water-soluble organic solvent (A) may be 0.110 to 0.650 parts by mass, 0.120 to 0.550 parts by mass, or 0.130 to 0.450 parts by mass.

[0024] When the total solid content is 1 part by mass, the amino alcohol content is preferably 0.010 parts by mass or more, more preferably 0.020 parts by mass or more, and even more preferably 0.035 parts by mass or more. Within these ranges, aggregation of particulate matter in the aqueous ink can be suppressed, and a decrease in wiping performance can be prevented. When the total solid content is 1 part by mass, the amino alcohol content is not particularly limited, but is preferably 0.200 parts by mass or less, more preferably 0.150 parts by mass or less, and even more preferably 0.080 parts by mass or less. Within these ranges, when a high viscosity amino alcohol is used, the increase in viscosity of the aqueous ink can be suppressed. In addition, the pH range of the aqueous ink can be appropriately adjusted, further improving the storage stability of the ink.

[0025] Thus, by providing an aqueous ink containing amino alcohol and a water-soluble organic solvent (A), with a solid content of 20% by mass or more of the total ink amount, a specified content of water-soluble organic solvent (A) relative to the total ink amount, a specified mass ratio of water-soluble organic solvent (A) to the solvent system, and a specified mass ratio of amino alcohol to the solid content, it is possible to provide an aqueous inkjet ink for textile printing that exhibits excellent wiping properties and suppresses solvent bleeding of printed materials.

[0026] The following is an explanation of amino alcohols. The amino alcohol may be either an aliphatic amine having a hydroxyl group or an aromatic amine having a hydroxyl group, or a combination thereof, but an aliphatic amine having a hydroxyl group is preferred. The aliphatic amine having a hydroxyl group may be a compound having an amino group and a saturated or unsaturated linear or branched hydrocarbon group, in which at least one hydrogen atom of the hydrocarbon group is substituted with a hydroxyl group, and among these, alkanolamines are preferred. In the amino alcohol, the number of hydroxyl groups is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 to 3.

[0027] The amino alcohol may be a monoamine, a polyhydric amine such as a diamine or triamine, or a combination thereof. From the viewpoint of controlling the basicity, the amino alcohol is preferably a monoamine, and among these, alkanol monoamines are preferred. From the viewpoint of controlling solubility and basicity, the amino alcohol is preferably a compound that does not contain heteroatoms except for the nitrogen atom and the oxygen atom contained in the hydroxyl group. The amino alcohol may be a primary amine compound, a secondary amine compound, or a tertiary amine compound, and these may be used in combination.

[0028] Examples of amino alcohols include 2,2',2''-nitrilotriethanol, di-2-propanolamine, 2-dimethylethanolamine, 2-amino-2-methyl-1-propanol, 1-amino-2-propanol, 3-amino-1-propanol, N-methylethanolamine, N,N-dimethylethanolamine, 1-amino-2-methylpropanol, monoethanolamine, dieethanolamine, triethanolamine, N,N-dimethylmonoethanolamine, trishydroxymethylaminomethane, N-methyldiethanolamine, N-methylethanolamine, N-phenylethanolamine, 3-aminopropyldiethylamine, and 2-amino-2-ethyl-1,3-propanediol. Among these, di-2-propanolamine and triethanolamine are preferred.

[0029] The boiling point of the amino alcohol is not particularly limited, but from the viewpoint of making the ink less volatile and less viscous, it is preferably 100 to 400°C, more preferably 130 to 360°C, and even more preferably 150 to 350°C. From the viewpoint of suppressing the volatilization of amino alcohol from the water-based ink, which also contributes to the wiping properties of the ink, the boiling point of the amino alcohol is preferably 100°C or higher, 130°C or higher, or 150°C or higher, and may be 200°C or higher, 250°C or higher, or 300°C or higher. The amino alcohol is preferably a water-soluble compound, for example, a compound that dissolves in 100g of water at 25°C in an amount of 0.1g or more, 1g or more, or 5g or more. Furthermore, in the formulation of the aqueous ink, the amino alcohol is preferably dissolved in the water and water-soluble organic solvent of the aqueous ink at 25°C.

[0030] Water-based inks preferably contain water, and the main solvent may be water. While there are no particular restrictions on the type of water used, it is preferable to use water that contains as few ionic components as possible. In particular, from the viewpoint of storage stability of the water-based ink, it is preferable to use water with a low content of polyvalent metal ions such as calcium. Suitable water options include, for example, deionized water, distilled water, or ultrapure water.

[0031] From the viewpoint of adjusting the viscosity of the ink, water is preferably included in an amount of 20 to 80% by mass, more preferably 40 to 70% by mass, and even more preferably 50 to 60% by mass, relative to the total amount of aqueous ink.

[0032] Water-based inks preferably contain a water-soluble organic solvent. As the water-soluble organic solvent, an organic compound that is liquid at room temperature (25°C) and soluble in water can be used, and it is preferable to use a water-soluble organic solvent that mixes uniformly with the same volume of water at 1 atmosphere and 20°C.

[0033] The following describes water-soluble organic solvent (A). The water-soluble organic solvent (A) has a boiling point of 250°C or higher, which suppresses the evaporation of the water-soluble organic solvent (A) from the water-based ink, increases the moisture retention of the water-based ink, suppresses the aggregation of particulate matter caused by the decrease in polarity due to the decrease in water content of the water-based ink, and prevents a decrease in the wiping properties of the ink. More preferably, the boiling point of the water-soluble organic solvent (A) is 260°C or higher, and even more preferably 280°C or higher. The boiling point of the water-soluble organic solvent (A) is not particularly limited, but from the viewpoint of adjusting the viscosity of the water-based ink, it is preferably 400°C or lower, 350°C or lower, or 300°C or lower. For example, the boiling point of the water-soluble organic solvent (A) may be 250-400°C, 260-350°C, or 280-300°C.

[0034] The water-soluble organic solvent (A) is one or more selected from the group consisting of polyalkylene glycols, polyalkylene glycol derivatives, and trihydric alcohols.

[0035] Examples of polyalkylene glycols include polyethylene glycol, polypropylene glycol, polyethylene-propylene glycol, and polytrimethylene glycol. The number-average molecular weight of polyalkylene glycol is preferably 100 to 800, and more preferably 150 to 400, from the viewpoint of adjusting the boiling point of the solvent and the viscosity of the ink. Here, the number-average molecular weight is the value obtained on a standard polystyrene basis by the GPC (gel permeation chromatography) method. Specific examples of polyalkylene glycols with a boiling point of 250°C or higher include triethylene glycol, tetraethylene glycol, polyethylene glycol, tripropylene glycol, and polypropylene glycol.

[0036] Examples of polyalkylene glycol derivatives include polyalkylene glycol monoalkyl ethers and polyalkylene glycol dialkyl ethers. For example, monoalkyl ethers or dialkyl ethers of polyethylene glycol, polypropylene glycol, polyethylene-propylene glycol, and polytrimethylene glycol are examples. Specific examples of polyalkylene glycol derivatives with a boiling point of 250°C or higher include triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether.

[0037] As the trihydric alcohol, saturated or unsaturated aliphatic trihydric alcohols are preferred, and saturated post-trihydric alcohols are more preferred. The number of carbon atoms in the trihydric alcohol is preferably 3 to 8, and more preferably 2 to 5. Specific examples of trihydric alcohols with a boiling point of 250°C or higher include glycerin, trimethylolethane, and 1,2,4-butanetriol.

[0038] The water-soluble organic solvent (A) is preferably glycerin, triethylene glycol, tripropylene glycol, or polyethylene glycol, more preferably glycerin or triethylene glycol, and these may be used in combination.

[0039] The water-soluble ink may further contain other water-soluble organic solvents in addition to the water-soluble organic solvent (A). Examples of other water-soluble organic solvents include lower alcohols, glycols, glycol ethers, β-thiodiglycols, sulfolanes, polyalkylene glycols and their derivatives with a boiling point of less than 250°C, trihydric alcohols and their derivatives with a boiling point of less than 250°C, and among these, glycols and glycol ethers are preferred. Examples of lower alcohols include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and 2-methyl-2-propanol. Examples of glycols include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 3-ethyl-1,3-butanediol, propylene glycol, and dipropylene glycol. Examples of glycol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, and triethylene glycol monomethyl ether. The boiling point of the other water-soluble organic solvents is preferably 100°C or higher, and more preferably 150°C or higher. The other water-soluble organic solvents may be used alone, or two or more may be used in combination, as long as they form a single phase with water and water-soluble organic solvent (A).

[0040] The water-based ink preferably contains, in addition to the water-soluble organic solvent (A), a water-soluble organic solvent (B) having a boiling point of less than 250°C. This further suppresses the occurrence of solvent bleeding in the printed material. The boiling point of the water-soluble organic solvent (B) is more preferably 245°C or lower, and even more preferably 230°C or lower. While not particularly limited, the boiling point of the water-soluble organic solvent (B) is preferably 100°C or higher, 150°C or higher, or 200°C or higher, from the viewpoint of making the ink less volatile. For example, the boiling point of the water-soluble organic solvent (B) may be 100-250°C, 150-245°C, or 200-230°C.

[0041] As the water-soluble organic solvent (B), one or more solvents with a boiling point of less than 250°C from the specific examples of water-soluble organic solvents described above can be used. Glycols are preferred as the water-soluble organic solvent (B). For example, examples of water-soluble organic solvent (B) include diethylene glycol, 1,3-butanediol, 3-methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, and 3-ethyl-1,3-butanediol. Preferably, diethylene glycol, dipropylene glycol, 1,3-propanediol, and 1,3-butanediol are used, and these may be used individually or in combination of two or more.

[0042] When the content of water-soluble organic solvents excluding the amino alcohol content is taken as 1 part by mass from the total content of water-soluble organic solvents, the content of water-soluble organic solvent (B) is preferably 0.500 parts by mass or more, more preferably 0.600 parts by mass or more, and even more preferably 0.800 parts by mass or more, from the viewpoint of suppressing the occurrence of solvent bleeding in printed materials. The mass ratio of this water-soluble organic solvent (B) may be 0.500 to 0.900 parts by mass, 0.600 to 0.880 parts by mass, or 0.800 to 0.850 parts by mass. From the viewpoint of further suppressing the occurrence of solvent bleeding in printed materials, it is preferable that all water-soluble organic solvents contained in the aqueous ink, excluding water-soluble organic solvent (A) and amino alcohol, have a boiling point of less than 250°C.

[0043] The water-soluble organic solvent (B) may be 1 to 80% by mass relative to the total amount of ink, and 5 to 50% by mass, 10 to 30% by mass, or 15 to 20% by mass are more preferred.

[0044] When other water-soluble organic solvents are included in addition to the water-soluble organic solvent (A), the total content of the water-soluble organic solvents is preferably 1 to 80% by mass, more preferably 5 to 40% by mass, and even more preferably 7 to 30% by mass, based on the total amount of ink.

[0045] Water-based inks may contain pigments. The pigments may be either white or non-white pigments. Water-based inks can be used to form images exhibiting white color by containing a white pigment. Furthermore, inks containing a white pigment can be applied to a substrate as a base layer for color printing to enhance the substrate's opacity. The white pigment may be either an inorganic or organic pigment, or a combination of both. Examples of white pigments include white inorganic pigments such as titanium dioxide, zinc oxide, zinc sulfide, antimony oxide, and zirconium oxide. Furthermore, white organic pigments such as hollow resin fine particles and solid resin fine particles can also be used. Among these, titanium dioxide pigment is preferred from the viewpoint of opacity. The average particle size of the white pigment, as the volume-based average value of the particle size distribution measured by dynamic light scattering, is preferably 50 nm or more, 100 nm or more, or 200 nm or more from the viewpoint of opacity, and preferably 500 nm or less, 400 nm or less, or 300 nm or less from the viewpoint of discharge stability. The average particle size of titanium dioxide pigment is more preferably 200 to 300 nm from the viewpoint of opacity and discharge stability. When using titanium dioxide pigment, it is preferable to use a product that has been surface-treated with alumina, silica, etc., in order to suppress the photocatalytic effect. The amount of surface treatment is preferably 5 to 20% by mass in the pigment.

[0046] Water-based inks can provide color inks by including non-white pigments. Examples of color inks include magenta ink, cyan ink, yellow ink, and black ink. The non-white pigment may be either an inorganic pigment or an organic pigment, and these may be used in combination.

[0047] Non-white pigments that can be used include organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, and blue-green lake pigments, as well as inorganic pigments such as carbon black and metal oxides. Examples of azo pigments include soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments. Examples of phthalocyanine pigments include metallic phthalocyanine pigments and metal-free phthalocyanine pigments. Examples of polycyclic pigments include quinacridone pigments, perylene pigments, perinone pigments, isoindoline pigments, isoindolinone pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, metal complex pigments, and diketopyrrolopyrrole (DPP). Examples of carbon black include furnace carbon black, lamp black, acetylene black, and channel black. From the viewpoint of dispensing stability and storage stability, the average particle size of non-white pigments is preferably 300 nm or less, more preferably 150 nm or less, and even more preferably 100 nm or less, as the volume-based average value of the particle size distribution measured by dynamic light scattering.

[0048] Self-dispersing pigments may be used as pigments. Self-dispersing pigments are pigments in which hydrophilic functional groups are introduced to the surface of the pigment by chemical or physical treatment. The hydrophilic functional groups introduced into the self-dispersing pigment are preferably ionic, and by charging the pigment surface anionic or cationic, the pigment particles can be stably dispersed in water by electrostatic repulsion. Preferred anionic functional groups include carboxyl groups, sulfo groups, and phosphate groups. Preferred cationic functional groups include quaternary ammonium groups and quaternary phosphonium groups. These hydrophilic functional groups may be directly bonded to the pigment surface or bonded via other atomic groups. Examples of other atomic groups include, but are not limited to, alkylene groups, phenylene groups, and naphthylene groups. Examples of pigment surface treatment methods include diazotization, sulfonation, hypochlorite treatment, humic acid treatment, and vacuum plasma treatment.

[0049] As self-dispersing pigments, for example, the CAB-O-JET series from Cabot Corporation, such as "CAB-O-JET200," "CAB-O-JET300," "CAB-O-JET250C," "CAB-O-JET260M," "CAB-O-JET270," and "CAB-O-JET450C," and from Orient Chemical Industries, Ltd., such as "BONJET BLACK CW-1," "BONJET BLACK CW-2," "BONJET BLACK CW-3," and "BONJET BLACK CW-4," can be preferably used (all are product names).

[0050] A pigment dispersion in which the pigment is pre-dispersed with a pigment dispersant may be used. Examples of commercially available pigment dispersions dispersed with a pigment dispersant include the HOSTAJET series from Clariant and the FUJI SP series from Fuji Pigment Co., Ltd. In addition, microencapsulated pigments in which the pigment is coated with resin may be used as the pigment.

[0051] Pigments may be used individually or in combination of two or more types. From the viewpoint of image density and ink viscosity, the amount of pigment is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, and even more preferably 2 to 10% by mass, relative to the total amount of ink. In the case of white pigments, from the viewpoint of opacity of the fabric, 3 to 30% by mass is preferred, 5 to 20% by mass is more preferred, and 7 to 15% by mass is even more preferred, based on the total amount of ink.

[0052] To stably disperse storage-stable pigments in storage-stable inks, pigment dispersants such as polymer dispersants and surfactant-type dispersants can be used. Examples of polymer dispersants include commercially available products such as the TEGO Disperse series from EVONIK, including "TEGO Disperse 740W," "TEGO Disperse 750W," "TEGO Disperse 755W," "TEGO Disperse 757W," and "TEGO Disperse 760W," and the Solsperse series from Lubrizol Japan, including "Solsperse 20000," "Solsperse 27000," "Solsperse 41000," "Solsperse 41090," "Solsperse 43000," "Solsperse 44000," and "Solsperse 46000." Examples include the Joncryl series from BASF Japan Ltd., such as "Joncryl 57," "Joncryl 60," "Joncryl 62," "Joncryl 63," "Joncryl 71," and "Joncryl 501"; products from Big Chemie Japan Co., Ltd., such as "DISPERBYK-102," "DISPERBYK-185," "DISPERBYK-190," "DISPERBYK-193," and "DISPERBYK-199"; and products from Daiichi Kogyo Seiyaku Co., Ltd., such as "Polyvinylpyrrolidone K-30" and "Polyvinylpyrrolidone K-90" (all are brand names).

[0053] Examples of surfactant-type dispersants include anionic surfactants such as the Demol series manufactured by Kao Corporation, including "Demol P," "Demol EP," "Demol N," "Demol RN," "Demol NL," "Demol RNL," and "Demol T-45," and nonionic surfactants such as the Emulgen series manufactured by Kao Corporation, including "Emulgen A-60," "Emulgen A-90," "Emulgen A-500," "Emulgen B-40," "Emulgen L-40," and "Emulgen 420" (all are product names). Furthermore, examples of surfactant-type dispersants include "Solspers 27000" (product name) manufactured by Lubrizol Japan Co., Ltd.; "borchiGenDFN (allyl alkyl biphenyl polyglycol ether)" (product name) manufactured by Borchers; "DISPERBYK-193" (product name) manufactured by Big Chemie Japan Co., Ltd.; and "Pionin D-6115 (aryl phenyl ether)", "Takesurf D-6108-W (polyoxyalkylene polystyrene phenyl ether)", and "Pionin D-6512 (polyoxyethylene polystyrene phenyl ether)" (all product names) manufactured by Takemoto Oil Co., Ltd.

[0054] The pigment dispersant may be used alone or in combination of two or more types. When using a pigment dispersant, the amount contained in the ink varies depending on the type and is not particularly limited, but generally, a mass ratio of 0.005 to 0.5 per 1 part pigment is preferred.

[0055] Water-based inks may contain water-dispersible resins. Examples of water-dispersible resins include binder resins. The inclusion of a binder resin in the water-based ink allows for the formation of a resin coating on the fabric, improving the ink image's fixation, abrasion resistance, and other properties.

[0056] The water-dispersible resin is preferably formulated in the aqueous ink in the form of a water-in-oil emulsion and is dispersible in the aqueous ink in the form of resin particles. The water-dispersible resin may be a self-emulsifying type with hydrophilic groups and / or hydrophilic segments introduced to ensure stable dispersion in water, or it may be water-dispersible through the use of an external emulsifier. The water-dispersible resin is preferably a resin that forms a transparent coating film so as not to affect the color of the pigment.

[0057] The water-dispersible resin may be an anionic resin, cationic resin, amphoteric resin, or nonionic resin. Considering the dispersion stability of the pigment in aqueous ink, anionic resins, amphoteric resins, nonionic resins, or combinations thereof can be preferably used, and anionic resins are more preferable. As the water-dispersible resin, anionic resins having anionic functional groups such as carboxyl groups, sulfo groups, and phosphate groups are preferred.

[0058] Water-dispersible resins are preferably present as resin particles in the ink. From the viewpoint of inkjet ejection performance, the average particle size of the resin particles is preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 150 nm or less. For example, the average particle size of the resin particles is preferably in the range of 10 nm to 300 nm. Furthermore, it is preferable that the average particle size of the resin particles in the resin emulsion added to the ink meets these ranges. Here, the average particle diameter of the resin is the average particle diameter based on volume, and is a value measured by dynamic light scattering.

[0059] Examples of water-dispersible resins include conjugated diene resins such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, and vinyl chloride-vinyl acetate copolymer; acrylic resins such as polymers of acrylic acid esters and methacrylic acid esters, or copolymers thereof with styrene, etc.; vinyl resins such as ethylene-vinyl acetate copolymer, or functionally modified resins using monomers containing functional groups such as carboxyl groups of these various resins; polyurethane resins such as polyether-type urethane resin, polyester-type urethane resin, polyester-ether-type urethane resin, and polycarbonate-type urethane resin; melamine resin, urea resin, polyester resin, polyolefin resin, silicone resin, polyvinyl butyral resin, alkyd resin, etc. Resin emulsions of these individual resins may be used, or hybrid resin emulsions combining two or more of these resins may be used. The resins can be used individually or in combination of two or more.

[0060] Preferred water-dispersible resins include water-dispersible urethane resins, water-dispersible (meth)acrylic resins, water-dispersible styrene (meth)acrylic resins, and water-dispersible polyester resins, with water-dispersible urethane resins and water-dispersible polyester resins being more preferred. These may be used in combination.

[0061] Examples of water-dispersible urethane resins include Superflex 300, Superflex 420, Superflex 460, Superflex 460S, Superflex 470, Superflex 740 (glass transition temperature -34℃), and Superflex 150HS from Daiichi Kogyo Seiyaku Co., Ltd., DAOTAN TW 6490 / 35WA from Daicel Ornex Co., Ltd., Takelac W-6061 from Mitsui Chemicals, Inc., and UW-1701F from Ube Industries, Ltd. (all are trade names). These are anionic resins having a urethane skeleton.

[0062] Examples of commercially available water-dispersible (meth)acrylic resins or water-dispersible styrene (meth)acrylic resins include Movinyl 6751D, Movinyl 6960, Movinyl 6963, Movinyl 702, Movinyl 8020, Movinyl 966A, Movinyl 6718, Movinyl 6750, and Movinyl 7720 from Nippon Synthetic Chemical Co., Ltd., Joncryl PDX-7341 and Joncryl PDX-7370 from BASF, and Neocryl A-1094 and Neocryl BT-62 from DSM. Among these, those with a glass transition temperature of 10°C or lower are preferred (all are trade names).

[0063] Examples of water-dispersible polyester resins include Elitel KT-0507, Elitel KT-8701, Elitel KT-8803, Elitel KT-9204, Elitel KT-9511, Elitel KA-1449S, Elitel KA-5071S from Unitika Ltd., and Byronal MD-1100, Byronal MD-1200, Byronal MD-1245, Byronal MD-1335, Byronal MD-1480, Byronal MD-1500, Byronal MD-1930, Byronal MD-1985, and Byronal MD-2000 from Toyobo Co., Ltd. (all are product names).

[0064] The water-dispersible resin can be used alone or in combination of two or more types. The water-dispersible resin, when present in a resin content of 1% or more by mass, 5% or more by mass, or 10% or more by mass relative to the total amount of ink, can further improve the fixation of the ink image on the printed material. Furthermore, the water-dispersible resin, when present in a resin content of 10% or more by mass, 13% or more by mass, or 15% or more by mass relative to the total amount of ink, can further increase the coating strength of the ink image on the printed material and further improve the abrasion resistance and fastness of the printed material. According to one embodiment, even when the water-based ink contains a large amount of water-dispersible material as solid components such as resin particles, aggregation of the resin particles is suppressed, thereby preventing a decrease in the wiping properties of the ink. From the viewpoint of adjusting the viscosity of the ink, it is preferable that the amount of water-dispersible resin is 30% by mass or less, 25% by mass or less, or 20% by mass or less, relative to the total amount of ink. For example, the water-dispersible resin may be present in an amount of 5-30% by mass, 10-25% by mass, or 15-20% by mass relative to the total amount of ink.

[0065] From the viewpoint of improving the fixation of the ink image and the strength of the coating film, as well as from the viewpoint of adjusting the viscosity of the ink, the amount of water-dispersible resin is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, and even more preferably 1.5 to 3 parts by mass per 1 part by mass of pigment.

[0066] Water-based inks may further contain crosslinking agents. The inclusion of crosslinking agents in water-based inks can further enhance the film strength of the ink image. Examples of crosslinking agents include carbodiimide compounds, isocyanate compounds, and oxazoline compounds. The amount of crosslinking agent is preferably 0.1 to 5% by mass, and more preferably 0.2 to 2% by mass, based on the total amount of aqueous ink.

[0067] Water-based inks may further contain surfactants. Any of the following surfactants may be used: anionic surfactants, cationic surfactants, amphoteric surfactants, or nonionic surfactants, but nonionic surfactants are more preferred. In addition, either low-molecular-weight surfactants or high-molecular-weight surfactants may be used.

[0068] The HLB value of the surfactant is preferably 5 to 20, and more preferably 10 to 18.

[0069] Examples of nonionic surfactants include ester-type surfactants such as glycerin fatty acid esters and fatty acid sorbitan esters; ether-type surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxypropylene alkyl ethers; ether ester-type surfactants such as polyoxyethylene sorbitan fatty acid esters; acetylene-based surfactants; silicone-based surfactants; and fluorine-based surfactants. Among these, acetylene-based surfactants such as acetylene glycol-based surfactants can be preferably used.

[0070] Examples of acetylene-based surfactants include acetylene glycol-based surfactants, acetylene alcohol-based surfactants, and surfactants having an acetylene group. The acetylene glycol-based surfactant is a glycol having an acetylene group, preferably a glycol with a symmetrical structure in which the acetylene group is located in the center, and may also have a structure in which ethylene oxide is added to the acetylene glycol. Examples of commercially available acetylene-based surfactants include the Surfinol series from Evonik Industries, such as "Surfinol 104E," "Surfinol 104H," "Surfinol 420," "Surfinol 440," "Surfinol 465," and "Surfinol 485," and the Orfin series from Nisshin Chemical Industry Co., Ltd., such as "Orfin E1004," "Orfin E1010," and "Orfin E1020" (all are product names).

[0071] Examples of silicone-based surfactants include polyether-modified silicone-based surfactants, alkyl-aralkyl copolymerized silicone-based surfactants, and acrylic silicone-based surfactants. Examples of commercially available silicone-based surfactants include "Sylface SAG002" and "Sylface 503A" manufactured by Nisshin Chemical Industry Co., Ltd. (both are product names).

[0072] Other nonionic surfactants include, for example, polyoxyethylene alkyl ether-based surfactants such as the Emulgen series manufactured by Kao Corporation, including "Emulgen 102KG," "Emulgen 103," "Emulgen 104P," "Emulgen 105," "Emulgen 106," "Emulgen 108," "Emulgen 120," "Emulgen 147," "Emulgen 150," "Emulgen 220," "Emulgen 350," "Emulgen 404," "Emulgen 420," "Emulgen 705," "Emulgen 707," "Emulgen 709," "Emulgen 1108," "Emulgen 4085," and "Emulgen 2025G" (all are product names).

[0073] Examples of anionic surfactants include the Emal series manufactured by Kao Corporation, such as "Emal 0," "Emal 10," "Emal 2F," "Emal 40," and "Emal 20C"; the Neoperex series, such as "Neoperex GS," "Neoperex G-15," "Neoperex G-25," and "Neoperex G-65"; the Perex series, such as "Perex OT-P," "Perex TR," "Perex CS," "Perex TA," "Perex SS-L," and "Perex SS-H"; and the Demol series, such as "Demol N," "Demol NL," "Demol RN," and "Demol MS" (all are product names).

[0074] Examples of cationic surfactants include the Acetamine series "Acetamine 24" and "Acetamine 86" manufactured by Kao Corporation, the Cortamine series "Cortamine 24P", "Cortamine 86P", "Cortamine 60W", and "Cortamine 86W", and the Sanizol series "Sanizol C" and "Sanizol B-50" (all are product names).

[0075] Examples of amphoteric surfactants include the Anchitol series manufactured by Kao Corporation, such as "Anchitol 20BS," "Anchitol 24B," "Anchitol 86B," "Anchitol 20YB," and "Anchitol 20N" (all are product names).

[0076] One type of surfactant may be used, or a combination of two or more types may be used. The surfactant is preferably present in an amount of 0.1 to 5% by mass, and more preferably 0.2 to 2% by mass, relative to the total amount of ink.

[0077] Water-based inks may also contain other components. These other components may include pH adjusters, preservatives, rust inhibitors, and defoamers.

[0078] The method for manufacturing aqueous ink is not particularly limited and can be manufactured by any known method. For example, all components can be added together or in separate portions to a stirrer such as a three-in-one motor and dispersed, and the ink can be obtained by passing it through a filter such as a membrane filter, if desired.

[0079] From the viewpoint of ink storage stability, the pH of water-based ink is preferably 7.0 to 10.0, and more preferably 7.5 to 9.0. The viscosity of the water-based ink can be adjusted as appropriate, but from the viewpoint of ejection performance, for example, a viscosity of 1 to 30 mPa·s at 23°C is preferable.

[0080] According to one embodiment, an aqueous inkjet ink for textile printing can be applied to a fabric to produce a printed product. Examples of fabrics include woven fabrics, knitted fabrics, and nonwoven fabrics.

[0081] The fibers that make up the fabric include, for example, inorganic fibers such as metal fibers, glass fibers, rock fibers, and mineral fiber; regenerated fibers such as cellulose-based and protein-based fibers; semi-synthetic fibers such as cellulose-based fibers; synthetic fibers such as polyamide, polyester, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, polyurethane, polyethylene, polypropylene, polystyrene, and polyfluoroethylene; and natural fibers such as cotton, linen, silk, and wool.

[0082] <Pretreatment solution> The fabric to which the water-based inkjet ink for textile printing is applied may be pre-treated or untreated. Using pre-treated fabric can improve the image quality of the ink image and also improve the adhesion of the ink image to the fabric. Pre-treated fabric can be obtained by applying a pre-treatment solution to the fabric.

[0083] As the pretreatment solution, a pretreatment solution containing a coagulant and water can preferably be used. As the flocculant, a component having the function of flocculating the coloring material in the ink on the fabric can be used. By this, when ink is further applied to the fabric to which the pretreatment liquid has been applied, the coloring material in the ink flocculates on the fabric, the image density can be increased more, and bleeding of the image can be prevented. As specific examples of the flocculant, metal salts, cationic polymers, organic acids, etc., or combinations thereof can be used. The total amount of the flocculant is preferably 1 to 30% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 15% by mass, in terms of the amount of the active ingredient, relative to the total amount of the pretreatment liquid.

[0084] As the metal salt, a polyvalent metal salt can preferably be used. The polyvalent metal salt is composed of a polyvalent metal ion having a valence of 2 or more and an anion. Examples of the polyvalent metal ion having a valence of 2 or more include, for example, Ca 2+ , Mg 2+ , Cu 2+ , Ni 2+ , Zn 2+ , Ba 2+ , etc. Examples of the anion include, for example, Cl - , NO3 - , CH3COO - , I - , Br - , ClO3 - , etc. Specific examples of the polyvalent metal salt include calcium chloride, calcium nitrate, magnesium nitrate, copper nitrate, calcium acetate, magnesium acetate, etc.

[0085] As the cationic polymer, a cationic water-soluble resin can preferably be used. Examples of the cationic water-soluble resin include, for example, polyethyleneimine (PEI), polyvinylamine, polyallylamine and its salts, polyvinylpyridine, copolymers of cationic acrylamide, etc. More specifically, for example, polydiallyldimethylammonium chloride, etc. can be used.

[0086] Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, tricarbaryl acid, glycolic acid, thioglycolic acid, lactic acid, malic acid, tartaric acid, citric acid, isocitric acid, gluconic acid, pyruvic acid, oxalacetic acid, diglycolic acid, benzoic acid, phthalic acid, mandelic acid, and salicylic acid.

[0087] The pretreatment solution preferably contains water. In addition to water, or instead of water, the pretreatment solution may contain a water-soluble organic solvent. Details of water and water-soluble organic solvents are as described above for water-based inks. As the water-soluble organic solvent, for example, one or more of those described above for water-based inks can be used individually or in combination. The amount of water is preferably 30 to 90% by mass, more preferably 40 to 85% by mass, and even more preferably 50 to 80% by mass, relative to the total amount of pretreatment solution. The amount of water-soluble organic solvent is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and even more preferably 15 to 30% by mass, based on the total amount of the pretreatment solution.

[0088] The pretreatment solution may further contain a surfactant. As the surfactant, for example, one or more of those described above for the aqueous ink can be used individually or in combination. Among these, nonionic surfactants are preferred, acetylene-based surfactants are more preferred, and acetylene glycol-based surfactants are even more preferred. The surfactant is preferably present in an amount of 0.1 to 10% by mass, and more preferably 0.2 to 5% by mass, relative to the total amount of the pretreatment solution.

[0089] The pretreatment solution may further contain other components. Examples of other components include pH adjusters, preservatives, rust inhibitors, and defoamers.

[0090] The method for producing the pretreatment solution is not particularly limited and can be produced by any known method. For example, it can be obtained by dispersing all components together or in separate portions in a stirrer such as a three-in-one motor, and optionally passing it through a filter such as a membrane filter.

[0091] <Method of manufacturing printed materials> The following describes a method for manufacturing printed materials using an aqueous inkjet ink for textile printing according to one embodiment. In one example, a printed fabric can be manufactured by applying a water-based inkjet ink for printing, according to one embodiment, to the fabric using an inkjet method. A pretreatment solution may be applied to the fabric before the water-based inkjet ink for printing is applied to it. A preferred method for manufacturing a printed fabric includes applying a pretreatment solution to a cloth and then applying an aqueous ink according to one embodiment to the cloth that has been treated with the pretreatment solution using an inkjet method. In this example, it is preferable that the pretreatment solution and the aqueous ink are each applied to the cloth using an inkjet method. Another preferred method for manufacturing a printed fabric includes applying a pretreatment solution to the fabric, applying an aqueous ink containing a white pigment to the pretreatment solution-treated fabric using an inkjet method, and applying an aqueous ink containing a non-white pigment to the fabric that has been treated with the aqueous ink containing a white pigment using an inkjet method. At least one of the aqueous ink containing a white pigment and the aqueous ink containing a non-white pigment is an aqueous ink according to one embodiment. In this example, it is preferable to apply the pretreatment solution, the aqueous ink containing a white pigment, and the aqueous ink containing a non-white pigment to the fabric using an inkjet method.

[0092] The inkjet method is a printing method that allows for easy and flexible image formation on demand without contact with the fabric. The inkjet method is not particularly limited and may be any of the following: piezo, electrostatic, or thermal. When using an inkjet printing device, it is preferable to eject droplets of pretreatment liquid or ink from the inkjet head based on a digital signal and to adhere the ejected droplets to the fabric. The inkjet printing device may be a serial head type or a line head type.

[0093] The following describes the process of applying the pretreatment solution to the fabric. The area to which the pretreatment solution is applied may be an area with the same shape as the image created with the water-based ink, a wider area including the shape of the image created with the water-based ink, or the entire surface of the fabric. It is preferable that the area to which the pretreatment solution is applied, the area to which the water-based ink is applied, and the area to which the color ink is applied overlap at least partially. As for how to apply the pretreatment solution to the fabric, for example, the pretreatment solution may be applied uniformly to the fabric surface using a brush, roller, bar coater, air knife coater, spray, etc., or the pretreatment solution may be printed onto the image area using a printing method such as an inkjet printing method, gravure printing method, or flexographic printing method. The amount of pre-treatment solution to apply to the fabric should be 5-200g / m². 2 Preferably, 10-100 g / m² 2 Preferably, 15-80 g / m 2 This is preferable.

[0094] Next, we will explain the process of applying water-based ink to a fabric that has been treated with a pre-treatment solution using an inkjet method. Preferably, the area to which the water-based ink is applied overlaps at least partially with the area to which the pretreatment solution is applied. The amount of water-based ink applied to the fabric is not particularly limited, but for example, 1 to 100 g / m² 2 Preferably, 5-50 g / m 2 This is preferable. When a water-based ink is a white ink and is applied to the fabric as a base layer for a non-white ink, the area to which the white ink is applied may be an area with the same shape as the image created with the non-white ink, a wider area including the shape of the image created with the non-white ink, or the entire surface of the fabric. When forming a base layer, the amount of white ink applied to the fabric is not particularly limited, but for example, 80-400 g / m² is possible. 2 Preferably, 120-250 g / m² 2 This is preferable.

[0095] After applying a pretreatment solution to the fabric, the aqueous ink may be applied to the fabric using a wet-on-wet method, or the fabric may be dried before applying the aqueous ink. In the wet-on-wet method, it is preferable that the aqueous ink is applied while the moisture has not been completely removed from the fabric to which the pretreatment solution has been applied. Preferably, the aqueous ink can be applied while the fabric to which the pretreatment solution has been applied remains wet. For example, it is preferable to apply the aqueous ink to the fabric without performing a drying process such as heat drying after applying the pretreatment solution to the fabric. Similarly, when applying a non-white ink to the fabric after applying white ink to form a base layer, the non-white ink may be applied to the fabric using a wet-on-wet method after applying the white ink, or the non-white ink may be applied to the fabric after drying.

[0096] A further step of heat-treating the fabric after applying the water-based ink can be added. This allows for better fixation of the ink image. The heat treatment temperature can be appropriately selected depending on the material of the fabric, etc. For example, a heat treatment temperature of 100°C or higher is preferred, and 150°C or higher is more preferred. From the viewpoint of reducing damage to the fabric, a heat treatment temperature of 200°C or lower is preferred. The heating device is not particularly limited, but for example, a heat press, roll heater, hot air device, infrared lamp heater, etc., can be used. The heating time can be set appropriately depending on the heating method, etc. For example, 1 second to 10 minutes is preferred, and 5 seconds to 5 minutes is also acceptable.

[0097] The steps of applying the pretreatment solution, applying the white ink, and applying the non-white ink may be performed using separate printing devices or using a single printing device. For example, two printing devices may be used, with the pretreatment solution application step performed on one of them and the white ink application and non-white ink application steps performed on the other.

[0098] An overcoat layer may be formed on the cloth after it has been coated with water-based ink. The overcoat layer can be formed by applying a post-treatment solution to the cloth after it has been coated with ink. As the post-treatment solution, for example, a solution containing a resin capable of forming a coating film and an aqueous medium or an oil-based medium can be used. After applying the water-based ink, a step of heating the cloth may be added, followed by the application of the post-treatment solution. After applying the water-based ink, the post-treatment solution may be applied using a wet-on-wet method. Furthermore, a step of heating the cloth may be added after the application of the post-treatment solution.

[0099] <Ink Set> According to one embodiment, an ink set comprising an aqueous inkjet ink for textile printing and a pretreatment solution can be provided. The aqueous inkjet ink for textile printing may be a combination of an aqueous ink containing a white pigment and an aqueous ink containing a non-white pigment. These ink sets may further include a posttreatment solution. Details of the aqueous inkjet ink for textile printing and the pretreatment solution are as described above. [Examples]

[0100] The present invention will be described in detail below with reference to examples. The present invention is not limited to the following examples. In the following description, unless otherwise specified, "%" indicates "mass%". Raw materials that are not specifically mentioned as being manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., etc., are available from these sources.

[0101] "Preparation of white pigment dispersions" 400g of titanium dioxide "TIPAQUE R-980" (product name, manufactured by Ishihara Sangyo Co., Ltd.) as a white pigment and 16g of "Demol P" (product name, manufactured by Kao Corporation) (4g of active ingredient) as a pigment dispersant were mixed with 584g of ion-exchanged water. Using a bead mill ("DYNO-MILL KDL Type A" (product name) manufactured by Shinmaru Enterprises, Ltd.), 0.5mmΦ zirconia beads were dispersed at a packing rate of 80% by volume and a residence time of 2 minutes to obtain a white pigment dispersion (pigment content 40%, solid content 41.6%).

[0102] "Preparation of black pigment dispersions" 300g of carbon black "MOGUL L" (product name, manufactured by Cabot Specialty Chemicals Inc.) as a black pigment and 90g of "Borch® Gen DFN" (product name, manufactured by Borchers sas) as a pigment dispersant were mixed with 610g of deionized water. Using a bead mill ("DYNO-MILL KDL A" (product name) manufactured by Shinmaru Enterprises Co., Ltd.), 0.5mmΦ zirconia beads were dispersed at a packing density of 85% by volume and a residence time of 9 minutes to obtain a black pigment dispersion (pigment content 30%, solid content 39%).

[0103] "Production of pigment inks" Tables 1 to 3 show the ink formulations and evaluation results. The raw materials were mixed according to the formulations shown in the tables, and the mixture was stirred at 100 rpm for 20 minutes using a mixing rotor to obtain pigment ink. In the tables, the content of pigment dispersion and resin emulsion are shown as the total amount including the aqueous medium, etc.

[0104] The ingredients used are as follows: White pigment dispersion (40% pigment content): Prepared according to the above formulation. Black pigment dispersion (30% pigment content): Prepared according to the above formulation. Resin emulsion "Superflex 470" (product name): Carbonate-type urethane resin emulsion, resin content 38%. "Elitel KT9204" resin emulsion (product name): Polyester resin emulsion, 30% resin content. Surfactant "Orphine E1010" (product name) (boiling point 418℃): Manufactured by Nisshin Chemical Industry Co., Ltd., acetylene glycol-based surfactant, active ingredient content 100% by mass.

[0105] Water-soluble organic solvents: diethylene glycol (boiling point 244°C), 1,3-butanediol (boiling point 207°C), 3-methyl-1,3-butanediol (boiling point 203°C), 2-ethyl-1,3-hexanediol (boiling point 245°C); water-soluble organic solvent (A): glycerin (boiling point 290°C), triethylene glycol (boiling point 288°C); amine compounds: 2,2',2''-nitrilotriethanol (boiling point 360°C), di-2-propanolamine (boiling point 249°C), 2-dimethylethanolamine (boiling point 139°C), triethylamine (boiling point 90°C), 2-amino-2-methyl-1-propanol (boiling point 165°C) are available from Fujifilm Wako Pure Chemical Industries, Ltd., etc.

[0106] The "Water-soluble organic solvent (A) / Water-soluble organic solvent (mass ratio)" shown in the table is calculated from the mass ratio of the water-soluble organic solvent (A) content, where the content of the water-soluble organic solvent minus the total amount of amine compounds is considered as 1 part by mass. The "Amine Compound / Solid Content (Mass Percentage)" shown in the table is calculated from the mass percentage of the amine compound content when the total solid content is considered to be 1 part by mass. Here, the amine compound content refers to the content of amino alcohols or alkylamines.

[0107] The following evaluations were conducted using each ink. The evaluation results are shown in the respective tables. "Ink wiping properties" Using each ink, a 100% solid A4 image was printed 10 times consecutively on a black cotton T-shirt (product name Printstar) manufactured by Toms Co., Ltd., cut to A4 size, using a mastermind inkjet printer "MMP-8130" (product name). After leaving it for one day, a wiping operation was performed, and the number of nozzles that ejected ink normally was measured using the nozzle check in the printer settings. The wiping performance of the ink was evaluated based on the ratio of nozzles that ejected ink normally to all nozzles, according to the following criteria. A: Over 90% B: 70% to less than 90% C: Less than 70%

[0108] "Prevention of solvent bleeding in printed materials" A black cotton T-shirt manufactured by Toms Co., Ltd. (product name "Printstar"), cut to A4 size, was printed with a 100% solid image using a mastermind inkjet printer "MMP-8130" (product name), and the printed material was obtained by heat pressing at 160°C for 2 minutes. After attaching A4 copy paper to the back of the printed material and leaving it for 1 day, the solvent bleeding of the printed material onto the paper was evaluated according to the following criteria. A: No bleeding onto the paper. B: There is some seepage onto the paper, but the solvent does not come off when the paper is touched by hand. C: The solvent seeps onto the paper, and touching the paper leaves a residue of solvent.

[0109] [Table 1]

[0110] [Table 2]

[0111] [Table 3]

[0112] As shown in the table, the inks in each example exhibited excellent wiping properties, preventing solvent bleeding in the resulting printed materials. Furthermore, the inks showed a viscosity suitable for inkjet inks, and the print quality was also good.

[0113] Comparative Example 1 did not contain amino alcohol, Comparative Example 2 had a small mass proportion of amino alcohol, Comparative Example 3 used alkylamine, and Comparative Example 4 did not contain water-soluble organic solvent (A). In these comparative examples, the wiping properties of the ink decreased. In Comparative Example 5, the mass proportion of water-soluble organic solvent (A) was large, causing solvent bleeding of the printed material. In Comparative Examples 6 and 7, the mass proportion of water-soluble organic solvent (A) was small, resulting in decreased wiping properties of the ink.

Claims

1. The ink contains water, a water-soluble organic solvent, an amino alcohol, a water-dispersible resin, and a pigment, with a solid content of 20% by mass or more of the total ink amount. The aforementioned water-soluble organic solvent comprises a water-soluble organic solvent (A) having a boiling point of 250°C or higher and being one or more selected from the group consisting of polyalkylene glycol, polyalkylene glycol derivatives, and trihydric alcohols, and a water-soluble organic solvent (B) having a boiling point of 200°C or higher and less than 250°C. The aforementioned water-soluble organic solvent (A) is 1 to 7% by mass relative to the total amount of ink. The aforementioned water-soluble organic solvent (B) is 10 to 30% by mass of the total amount of ink. When the total content of the water-soluble organic solvent is 1 part by mass, the content of the water-soluble organic solvent (A) is 0.110 parts by mass or more. A water-based inkjet ink for textile printing, wherein the content of the amino alcohol is 0.010 parts by mass or more when the total content of solids is 1 part by mass.

2. The aqueous inkjet ink for textile printing according to claim 1, wherein the content of the aqueous organic solvent (A) is 0.150 parts by mass or more when the total content of the aqueous organic solvent is 1 part by mass.

3. The aqueous inkjet ink for textile printing according to claim 1 or 2, wherein the content of the amino alcohol is 0.030 parts by mass or more when the total content of solids is 1 part by mass.

4. A water-based inkjet ink for textile printing according to any one of claims 1 to 3, wherein the content of the water-soluble organic solvent (B) is 0.500 parts by mass or more when the total content of the water-soluble organic solvent is 1 part by mass.

5. A method for producing a printed fabric, comprising applying an aqueous inkjet ink for printing described in any one of claims 1 to 4 to a cloth using an inkjet method.

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