Manufacturing method for printed materials

Abstract

To provide a printed matter which is excellent in concealment property by white ink, and can suppress generation of cracking of an ink image after cleaning.SOLUTION: A method for manufacturing a printed matter includes the steps of: applying a treatment liquid containing a coagulant to a cloth by an inkjet method; applying white ink having charge density of 30 μeq / g or more to the cloth to which the treatment liquid has been applied by a wet-on-wet method by an inkjet method; and applying color ink having Young's modulus of a dry film of 3.0 MPa or less to the cloth to which the white ink has been applied by the wet-on-wet method by the inkjet method.SELECTED DRAWING: None

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a method for producing a textile print. [Background technology]

[0002] BACKGROUND ART In addition to screen printing and roller printing, ink-jet printing has been attracting attention as a method for printing images such as letters, pictures, and designs onto fabrics such as woven fabrics, knitted fabrics, and nonwoven fabrics.

[0003] Printed items are required to have high durability. Patent Document 1 describes a textile printing method for obtaining a printed item with excellent abrasion fastness using an ink composition and a coating composition having a higher Young's modulus of a dried coating film than that of the dried coating film of the ink composition. Patent Document 2 describes that by adding a crosslinking agent to an inkjet textile printing composition, the resulting printed matter tends to have better abrasion fastness.

[0004] When printing on a substrate such as a dark-colored fabric using an inkjet printing method, one method for improving the color development of color inks is to first print white ink on the substrate and then print color inks on top of that. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-99790 [Patent Document 2] Japanese Patent Application Publication No. 2018-131581 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide a printed item that has excellent hiding power with white ink and can reduce the occurrence of cracking of the ink image after washing. [Means for solving the problem]

[0007] One embodiment of the present invention relates to a method for producing a printed textile, comprising the steps of: applying a treatment liquid containing a flocculant to a cloth by an inkjet system; applying a white ink having a charge density of 30 μeq / g or more to the cloth to which the treatment liquid has been applied by a wet-on-wet method by an inkjet system; and applying a color ink having a Young's modulus of a dried coating film of 3.0 MPa or less to the cloth to which the white ink has been applied by a wet-on-wet method by an inkjet system. [Effects of the Invention]

[0008] According to one embodiment of the present invention, it is possible to provide a printed item that has excellent hiding power with white ink and that can reduce the occurrence of cracking of ink images after washing. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail, but it goes without saying that the present invention is not limited to these embodiments and various modifications and changes may be made.

[0010] A method for producing a printed textile according to one embodiment includes the steps of applying a treatment liquid containing a flocculant to a cloth by an inkjet system, applying a white ink having a charge density of 30 μeq / g or more to the cloth to which the treatment liquid has been applied by a wet-on-wet method by an inkjet system, and applying a color ink having a Young's modulus of a dried coating film of 3.0 MPa or less to the cloth to which the white ink has been applied by a wet-on-wet method by an inkjet system.

[0011] This method for producing a printed item can provide a printed item that has excellent hiding power with white ink and that can reduce the occurrence of cracking of the ink image after washing. Without being bound by theory, the reason for this is thought to be as follows. When a white ink and a color ink are applied to a fabric to which a treatment liquid has been applied by a wet-on-wet method, the drying steps after application of the treatment liquid and the white ink are not required, which can improve productivity. However, this can also result in a decrease in the hiding power of the white ink and a tendency for cracking of the ink image after washing. However, when the charge density of the white ink is 30 μeq / g or more, the white ink tends to react more easily with the treatment liquid, which makes it easier to suppress the penetration of the white ink into the interior of the fabric, and can improve the hiding power. Furthermore, to enhance the hiding power of the white ink, it is preferable for the white ink to contain a component that readily reacts with the flocculant in the treatment liquid. However, if the white ink contains such a component, the white ink film may become uneven, and the resulting printed textile may be prone to cracking of the ink image after washing. Applying a color ink with a Young's modulus of 3.0 MPa or less on top of the white ink layer facilitates making the ink film of the ink image flexible. Furthermore, when the charge density of the white ink is 30 μeq / g or higher, the white ink and the flocculant can react sufficiently, making it less likely for the color ink applied after the white ink to react with the flocculant, thereby preventing a decrease in the flexibility of the color ink film. These factors are believed to reduce the occurrence of cracking of the ink image after washing.

[0012] In the case of the wet-on-wet method, the white ink and the color inks may mix, resulting in a decrease in the image density of the color ink. This method for producing a printed textile can prevent a decrease in the image density of the color ink. Without being bound by theory, one possible reason for this is that when the charge density of the white ink is 30 μeq / g or higher, components such as pigment and resin in the white ink react with the aggregating agent in the treatment liquid relatively quickly and aggregate, causing the ink to thicken and become less likely to mix with the color ink.

[0013] The cloth, treatment liquid, white ink, and color ink will be described below.

[0014] <Cloth> Examples of fabrics include natural fibers such as cotton, silk, wool, and linen; chemical fibers such as polyester, acrylic, polyurethane, nylon, rayon, cupra, and acetate; and blends of these fibers. Furthermore, fabrics may be woven, knitted, or nonwoven fabrics.

[0015] <Processing liquid> The treatment liquid may include a flocculant.

[0016] The flocculant may be a component that has the effect of flocculating the coloring material in the ink on the substrate fabric. For example, a metal salt, a cationic polymer, an organic acid, or a combination thereof may be used. A polyvalent metal salt is preferred as the metal salt.

[0017] The content of the flocculant (amount of active ingredient) is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total amount of the treatment liquid. The content of the flocculant (amount of active ingredient) is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on the total amount of the treatment liquid. The content of the flocculant (amount of active ingredient) is preferably 1 to 50% by mass, more preferably 10 to 45% by mass, and even more preferably 15 to 40% by mass, based on the total amount of the treatment liquid. When two or more types of flocculants are used, the content of the flocculants mentioned above is the total content thereof.

[0018] As the metal salt, a polyvalent metal salt can be preferably used. Polyvalent metal salts are composed of divalent or higher polyvalent metal ions and anions. Examples of divalent or higher polyvalent metal ions include Ca. 2+ , Mg 2+ , Cu 2+ , Ni 2+ , Zn 2+ , Ba 2+ Examples of anions include Cl - , NO3 - , CH3COO - , I -, Br - , ClO3 - Specific examples of polyvalent metal salts include calcium chloride, calcium nitrate, magnesium nitrate, copper nitrate, calcium acetate, and magnesium acetate.

[0019] These metal salts may be used alone or in combination of two or more. The content of the metal salt (amount of active ingredient) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total amount of the treatment liquid. On the other hand, the content of the metal salt (amount of active ingredient) is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on the total amount of the treatment liquid. The content of the metal salt (amount of active ingredient) is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, and even more preferably 15 to 40% by mass, based on the total amount of the treatment liquid. When two or more types of metal salts are used, the content of the metal salts mentioned above is the total content thereof. When a metal salt hydrate is used as the polyvalent metal salt, the amount of the polyvalent metal salt (amount of active ingredient) is the amount converted into the anhydrous salt.

[0020] The cationic polymer is preferably a cationic water-soluble resin.

[0021] Examples of cationic water-soluble resins include polyethyleneimine (PEI), polyvinylamine, polyallylamine and its salts, polyvinylpyridine, cationic acrylamide copolymers, etc. More specifically, for example, polydiallyldimethylammonium chloride can be used.

[0022] Examples of commercially available cationic water-soluble resins include the Sharol series "Sharol DC-303P" and "Sharol DC-902P" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., the Unisense series "Unisense FCA1000L" and "Unisense FPA100L" manufactured by Senka Corporation, and the HC Polymer series "HC Polymer 1S," "HC Polymer 1N," "HC Polymer 1NS," "HC Polymer 2," and "HC Polymer 2L" manufactured by Osaka Organic Chemical Industry Ltd. (all trade names). Commercially available polyethyleneimine products include, for example, the Epomin series manufactured by Nippon Shokubai Co., Ltd., such as "Epomin SP-006," "Epomin SP-012," "Epomin SP-018," and "Epomin SP-200"; and "Lupasol FG," "Lupasol G20 Waterfree," and "Lupasol PR 8515" manufactured by BASF Japan Ltd. (all trade names). Commercially available polyallylamine products include, for example, allylamine polymers "PAA-01," "PAA-03," and "PAA-05," allylamine hydrochloride polymers "PAA-HCL-01," "PAA-HCL-03," and "PAA-HCL-05," and allylamine amide sulfate polymer "PAA-SA" (all trade names), all of which are manufactured by Nitto Boseki Co., Ltd.

[0023] The cationic polymers may be used alone or in combination of two or more. The content (solid content) of the cationic polymer is preferably 5 to 50 mass %, more preferably 10 to 45 mass %, and more preferably 15 to 40 mass %, based on the total amount of the treatment liquid. When two or more kinds of cationic polymers are used, the content of the cationic polymers mentioned above is the total content thereof.

[0024] 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, tricarballylic 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, salicylic acid, etc. Among these, acetic acid is preferred.

[0025] The organic acids may be used alone or in combination of two or more. The content of the organic acid is preferably 5 to 50 mass %, more preferably 10 to 45 mass %, and even more preferably 15 to 40 mass %, based on the total amount of the treatment liquid. When two or more organic acids are used, the content of the organic acids mentioned above is the total content thereof.

[0026] The treatment liquid preferably contains water as an aqueous solvent. The water is not particularly limited, but examples thereof include ion-exchanged water, distilled water, and ultrapure water.

[0027] 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, based on the total amount of the treatment liquid.

[0028] The treatment liquid preferably contains a water-soluble organic solvent. The water-soluble organic solvent may be an organic compound that is liquid at room temperature and soluble in water, and it is preferable to use a water-soluble organic solvent that is uniformly miscible with the same volume of water at 1 atmosphere and 20° C. Examples of the water-soluble organic solvent include lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and 2-methyl-2-propanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polypropylene glycol; glycerins such as glycerin, diglycerin, triglycerin, and polyglycerin; acetins such as monoacetin and diacetin; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diacetin, and the like. Examples of suitable water-soluble organic solvents include glycol ethers such as ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, 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; triethanolamine, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, β-thiodiglycol, and sulfolane. The boiling point of the water-soluble organic solvent is preferably 100° C. or higher, and more preferably 150° C. or higher.

[0029] These water-soluble organic solvents may be used alone or in combination of two or more as long as they form a single phase with water. The content of the water-soluble organic solvent is preferably 5 to 50 mass %, more preferably 10 to 40 mass %, and even more preferably 15 to 30 mass %, based on the total amount of the treatment liquid. When two or more water-soluble organic solvents are used, the content of the water-soluble organic solvents mentioned above is the total content thereof.

[0030] The treatment liquid preferably contains a surfactant. The surfactant may be an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant, with nonionic surfactants being more preferred. Furthermore, either a low-molecular-weight surfactant or a high-molecular-weight surfactant may be used.

[0031] The HLB value of the surfactant is preferably 5-20, and more preferably 10-18.

[0032] Examples of nonionic surfactants include ester surfactants such as glycerin fatty acid esters and fatty acid sorbitan esters; ether surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers and polyoxypropylene alkyl ethers; ether ester surfactants such as polyoxyethylene sorbitan fatty acid esters; acetylene surfactants; silicone surfactants; fluorine surfactants; etc. Among these, acetylene surfactants such as acetylene glycol surfactants are preferably used.

[0033] Examples of the acetylene surfactant include an acetylene glycol surfactant, an acetylene alcohol surfactant, and a surfactant having an acetylene group. The acetylene glycol surfactant is a glycol having an acetylene group, preferably a glycol having a symmetrical structure with the acetylene group located in the center, and may have a structure in which ethylene oxide is added to acetylene glycol. Commercially available acetylene surfactants include, for example, the Surfynol series manufactured by Evonik Industries, such as "Surfynol 104E," "Surfynol 104H," "Surfynol 420," "Surfynol 440," "Surfynol 465," and "Surfynol 485," and the Olfin series manufactured by Nissin Chemical Industry Co., Ltd., such as "Olfin E1004," "Olfin E1010," and "Olfin E1020" (all trade names).

[0034] Examples of silicone surfactants include polyether-modified silicone surfactants, alkyl-aralkyl-co-modified silicone surfactants, and acrylic silicone surfactants. Examples of commercially available silicone surfactants include "Silface SAG002" and "Silface 503A" manufactured by Nissin Chemical Industry Co., Ltd. (both are trade names).

[0035] Other nonionic surfactants include polyoxyethylene alkyl ether surfactants such as those in 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 trade names).

[0036] Examples of anionic surfactants include the Emeral series, manufactured by Kao Corporation, such as "Emeral 0," "Emeral 10," "Emeral 2F," "Emeral 40," and "Emeral 20C," the Neopelex series, such as "Neopelex GS," "Neopelex G-15," "Neopelex G-25," and "Neopelex G-65," the Pelex series, such as "Pelex OT-P," "Pelex TR," "Pelex CS," "Pelex TA," "Pelex SS-L," and "Pelex SS-H," and the Demol series, such as "Demol N," "Demol NL," "Demol RN," and "Demol MS" (all of which are trade names).

[0037] Examples of cationic surfactants include the Acetamine series (manufactured by Kao Corporation) such as "Acetamine 24" and "Acetamine 86," the Cortamine series (manufactured by Kao Corporation) such as "Cortamine 24P," "Cortamine 86P," "Cortamine 60W," and "Cortamine 86W," and the Sanisol series (manufactured by Kao Corporation) such as "Sanisol C" and "Sanisol B-50" (all trade names).

[0038] Examples of amphoteric surfactants include the Amphitol series manufactured by Kao Corporation, such as Amphitol 20BS, Amphitol 24B, Amphitol 86B, Amphitol 20YB, and Amphitol 20N (all trade names). The above surfactants are preferably used alone, but two or more of them may be used in combination.

[0039] The content of the surfactant is preferably 0.1 to 10 mass % of the total amount of the treatment liquid, more preferably 0.2 to 5 mass %, and even more preferably 0.4 to 2 mass %. When two or more surfactants are used, the content of the surfactants mentioned above is the total content thereof.

[0040] The treatment liquid may further contain other components, such as an antifoaming agent, a pH adjuster, an antioxidant, and a preservative, as required.

[0041] The method for producing the treatment solution is not particularly limited, and the treatment solution can be produced by any known method. For example, the treatment solution can be obtained by dispersing all of the components in a mixer such as a Three-One Motor, either all at once or in portions, and then passing the mixture through a filter such as a membrane filter, if desired.

[0042] The charge density of the treatment solution is preferably 1 to 400 μeq / g, more preferably 10 to 300 μeq / g. Here, the charge density is the charge density measured according to the streaming potential method. The charge density of the treatment solution is the amount of charge per amount of active ingredient in the treatment solution (unit: μeq / g). The amount of active ingredient is the total amount of nonvolatile or solid content contained in the treatment solution, mainly the amount after removing the solvent from the treatment solution. Specifically, the treatment solution is diluted 100 times with water, and this diluted treatment solution is titrated with 0.0025 N polyvinyl potassium sulfate (PVSK) solution. The reaction endpoint at which the streaming potential of the diluted treatment solution becomes 0 V is measured, and the total charge of the diluted treatment solution can be calculated from the amount of PVSK solution used up to this reaction endpoint. The total charge of this diluted treatment solution divided by the amount of active ingredient contained in the diluted treatment solution is the charge density (μeq / g) of the treatment solution. For example, a colloid particle charge meter ("Model CAS" manufactured by AFG ANALYTIC GmbH) can be used as the charge density measuring device.

[0043] <White ink> As the white ink, ink having a charge density of 30 μeq / g or more can be used.

[0044] Here, the charge density is the charge density measured according to the streaming potential method. The charge density of the ink is the amount of charge per unit of active ingredient in the ink (unit: μeq / g). The amount of active ingredient is the total amount of nonvolatile or solid content in the ink, and is primarily the amount after removing the solvent from the ink. For example, if materials such as pigment dispersions, dispersants, or resin emulsions of water-dispersible resins are used and contain solvents, the amount of these solvents is also removed to determine the amount of active ingredient. Specifically, the ink is diluted 100 times with water, and while titrating this diluted ink with 0.0025N polydiallyldimethylammonium chloride (polyDADMAC) solution, the reaction endpoint at which the flow potential of the diluted ink reaches 0 V is measured, and the total charge of the diluted ink can be calculated from the amount of polyDADMAC solution used up to this reaction endpoint. The charge density of the ink (μeq / g) is determined by dividing the total charge of the diluted ink by the amount of active ingredient contained in the diluted ink. For example, a colloid particle charge meter ("Model CAS" manufactured by AFG ANALYTIC GmbH) can be used as the charge density measuring device.

[0045] The charge density of the white ink is preferably 30 μeq / g or more, more preferably 35 μeq / g or more, and even more preferably 40 μeq / g or more. On the other hand, the charge density of the white ink is preferably 150 μeq / g or less, and more preferably 120 μeq / g or less. The charge density of the white ink is, for example, more preferably 30 to 150 μeq / g, more preferably 35 to 150 μeq / g, and even more preferably 40 to 120 μeq / g.

[0046] The charge density of the white ink can be adjusted by appropriately selecting the components contained in the white ink. For example, the charge density of the ink can be adjusted by the amount of counter ions of the ionic groups in the materials constituting the ink. This amount of counter ions indicates the amount of ions per particle mass. Generally, the greater the amount of counter ions per particle mass, the higher the charge density tends to be. For example, it is preferable to adjust the charge density by the amount of counter ions in the pigment or water-dispersible resin in the ink. The charge density of the ink can also be adjusted by adding an ionic component such as a dispersion aid to the ink. Alternatively, the charge density of the ink may be adjusted by combining several methods.

[0047] The white ink preferably contains, for example, a coloring material and a resin, such as a polymer dispersant or a water-dispersible resin, which will be described later.

[0048] The white ink preferably contains a white pigment as a coloring material. Examples of white pigments include inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, antimony oxide, and zirconium oxide. Furthermore, white pigments such as hollow resin microparticles and polymer microparticles can also be used. Among these, titanium oxide is preferably used from the viewpoint of hiding power. The average particle diameter of titanium oxide is preferably 50 nm or more from the viewpoint of hiding power, and preferably 500 nm or less from the viewpoint of ejection stability. When titanium oxide is used, it is preferable to use titanium oxide that has been surface-treated with alumina or silica to suppress photocatalytic activity. The amount of surface treatment is preferably 5 to 20 mass % of the pigment.

[0049] As the pigment, a self-dispersing pigment, which will be described later, may be blended. Alternatively, a pigment dispersion in which a pigment is previously dispersed with a pigment dispersant may be used, or a pigment dispersion in which a pigment is dispersed with a pigment dispersant as described below may be used.

[0050] The coloring materials may be used alone or in combination of two or more.

[0051] The content of the coloring material is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and even more preferably 5 to 15% by mass, of the total amount of the white ink from the viewpoint of hiding power, etc. When two or more coloring materials are used, the content of the coloring materials mentioned above is the total content thereof.

[0052] When a pigment is used as a coloring material in the white ink, a pigment dispersant, such as a polymer dispersant or a surfactant-type dispersant, can be used to stably disperse the pigment in the white ink. Examples of commercially available polymer dispersants include the TEGO Disperse series manufactured by EVONIK, such as "TEGO Disperse 740W," "TEGO Disperse 750W," "TEGO Disperse 755W," "TEGO Disperse 757W," and "TEGO Disperse 760W," and the Solsperse series manufactured by Lubrizol Japan, such as "Solsperse 20000," "Solsperse 27000," "Solsperse 41000," "Solsperse 41090," "Solsperse 43000," "Solsperse 44000," and "Solsperse 46000." Examples include the JONCRYL series manufactured by BASF Japan Ltd., such as "JONCRYL 57," "JONCRYL 60," "JONCRYL 62," "JONCRYL 63," "JONCRYL 71," and "JONCRYL 501," and the like; manufactured by BYK Japan Co., Ltd., "DISPERBYK-102," "DISPERBYK-185," "DISPERBYK-190," "DISPERBYK-193," and "DISPERBYK-199," and the like; and manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., "Polyvinylpyrrolidone K-30" and "Polyvinylpyrrolidone K-90" (all trade names). 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 trade names).

[0053] The above pigment dispersants may be used alone or in combination of two or more. When a pigment dispersant is used, the amount to be blended in the ink varies depending on the type and is not particularly limited, but in general, the mass ratio of the active ingredient (pigment concentration) to the pigment is preferably 0.005 to 0.5.

[0054] The white ink preferably contains water as an aqueous solvent, and the main solvent may be water. The water is not particularly limited, but is preferably one that contains as few ionic components as possible. In particular, from the viewpoint of ink storage stability, it is preferable that the content of polyvalent metal ions such as calcium is low. Examples of water that can be used include ion-exchanged water, distilled water, and ultrapure water.

[0055] From the viewpoint of adjusting the ink viscosity, the water content is preferably 30 to 90% by mass, more preferably 40 to 85% by mass, and even more preferably 50 to 80% by mass, based on the total amount of the white ink.

[0056] The white ink may contain a water-soluble organic solvent. As the water-soluble organic solvent, an organic compound that is liquid at room temperature and soluble in water can be used, and it is preferable to use a water-soluble organic solvent that is uniformly miscible with the same volume of water at 20°C under 1 atmosphere.

[0057] The water-soluble organic solvent can be selected from those described above for the treatment liquid. These water-soluble organic solvents may be used alone or in combination of two or more kinds as long as they form a single phase with water. The content of the water-soluble organic solvent is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 10 to 30% by mass, based on the total amount of the white ink. When two or more water-soluble organic solvents are used, the content of the water-soluble organic solvents mentioned above is the total content thereof.

[0058] The white ink preferably contains a surfactant.

[0059] The surfactant may be any of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, with nonionic surfactants being more preferred. In addition, either low-molecular-weight surfactants or polymeric surfactants may be used.

[0060] The HLB value of the surfactant is preferably 5-20, and more preferably 10-18.

[0061] The surfactant may be selected from those described above for the treatment liquid. Among these, acetylene-based surfactants such as acetylene glycol-based surfactants can be preferably used.

[0062] The surfactants may be used alone or in combination of two or more. The content of the surfactant is preferably 0.1 to 5% by mass, and more preferably 0.2 to 2% by mass, based on the total amount of the white ink. When two or more surfactants are used, the content of the surfactants mentioned above is the total content thereof.

[0063] The white ink may further contain a water-dispersible resin. When the water-dispersible resin is contained, a good reaction between the flocculant in the treatment liquid and the white ink is easily obtained, and good hiding power of the white ink is easily obtained.

[0064] The water-dispersible resin is preferably resin particles that can be dispersed in an aqueous solvent. The water-dispersible resin can be blended into the ink, for example, as an oil-in-water resin emulsion. The water-dispersible resin may be a self-emulsifying resin in which a hydrophilic component is introduced to stably disperse it in water, or may be a resin that becomes water-dispersible by the use of an external emulsifier.

[0065] From the viewpoint of inkjet ejection properties, the average particle diameter of the water-dispersible resin 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 diameter of the water-dispersible resin may be in the range of 10 nm to 300 nm. Here, the average particle diameter of the water-dispersible resin is the average particle diameter on a volume basis, and is a value measured by a light scattering method.

[0066] As the type of water-dispersible resin, it is preferable to use a resin that forms a transparent coating film.

[0067] 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 of these with styrene, etc.; vinyl resins such as ethylene-vinyl acetate copolymers, or functional group-modified resins of these various resins with a monomer containing a functional group such as a carboxyl group; Examples of water-dispersible resins include melamine resins, urea resins, polyurethane resins, unsaturated polyester resins, polyolefin resins, silicone resins, polyvinyl butyral resins, alkyd resins, etc. Resin emulsions of these resins alone may be used, or hybrid resin emulsions may be used.

[0068] The water-dispersible resin may be anionic, cationic, nonionic or amphoteric, with anionic water-dispersible resins being preferred. The anionic water-dispersible resin may be one in which anionic groups are present on the particle surface, such as a self-emulsifying resin, or one in which the surface of the resin particles has been surface-treated by attaching an anionic dispersant to the surface. Representative anionic groups include carboxyl groups, sulfo groups, and phosphate groups. Examples of the anionic dispersant include anionic surfactants.

[0069] The white ink preferably contains a water-dispersible resin A and a water-dispersible resin B, which have different charge densities. If the water-dispersible resin A has a lower charge density and the water-dispersible resin B has a higher charge density, the water-dispersible resin B, which has a higher charge density, forms a film, and then the water-dispersible resin A, which has a lower charge density, forms a film that fills in any unevenness in the film of the water-dispersible resin B, which is thought to further reduce cracking of the ink image after washing. The charge density of water-dispersible resin A is preferably 60 μeq / g or less, more preferably 55 μeq / g or less, and even more preferably 50 μeq / g or less. The charge density of water-dispersible resin B is preferably 65 μeq / g or more, more preferably 70 μeq / g or more, and preferably 75 μeq / g or more. In one embodiment, the white ink preferably contains water-dispersible resin A having a charge density of 60 μeq / g or less, 55 μeq / g or less, or 50 μeq / g or less, and water-dispersible resin B having a charge density of 65 μeq / g or more, 70 μeq / g or more, or 75 μeq / g or more. For example, the white ink preferably contains water-dispersible resin A having a charge density of 55 μeq / g or less and water-dispersible resin B having a charge density of 75 μeq / g or more.

[0070] The water-dispersible resin A and the water-dispersible resin B are not particularly limited and can be independently selected from the resins described above, etc. The water-dispersible resin A and the water-dispersible resin B are preferably anionic water-dispersible resins. The mass ratio of the contents (solid contents) of the water-dispersible resin A and the water-dispersible resin B (water-dispersible resin A:water-dispersible resin B) is preferably 2:1 to 2:3.

[0071] The charge density of the water-dispersible resin is measured by the streaming potential method. The charge density of the water-dispersible resin is the amount of charge per unit of active ingredient (unit: μeq / g). Specifically, a resin emulsion of the water-dispersible resin is diluted with water to a solids content of 0.05% by mass to prepare a diluted solution. While titrating this diluted solution with 0.0025N polydiallyldimethylammonium chloride (polyDADMAC) solution, the reaction endpoint at which the streaming potential of the diluted solution reaches 0 V is measured. The total charge of the diluted solution can be calculated from the amount of polyDADMAC solution used up to this reaction endpoint. The charge density (μeq / g) of the water-dispersible resin is determined by dividing the total charge of the diluted solution by the amount of solids contained in the diluted solution. For example, a colloid particle charge meter ("Model CAS" manufactured by AFG ANALYTIC GmbH) can be used as the charge density measuring device.

[0072] Examples of commercially available water-dispersible resins include "Superflex 460" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "UW-1005D-C1" and "UW-1527DF" manufactured by Ube Industries, Ltd., "DAOTAN TW6490 / 35WA," "DAOTAN TW6460 / 35WA," and "DAOTAN TW6490 / 30WA" manufactured by Daicel-Allnex Corporation, "NeoRez R986" manufactured by DSM, "Mowinyl 6763" manufactured by Japan Coating Resins Co., Ltd., and "ADEKA BONTITAR HUX-370" manufactured by ADEKA Corporation (all trade names).

[0073] These water-dispersible resins may be used alone or in combination of two or more. The content (solid content) of the water-dispersible resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, relative to the total amount of the white ink. The content (solid content) of the water-dispersible resin is preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to the total amount of the white ink. The content (solid content) of the water-dispersible resin is preferably 1 to 30% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass, relative to the total amount of the white ink. When two or more water-dispersible resins are used, the content of the water-dispersible resins mentioned above is the total content thereof.

[0074] The content (solid content) of the water-dispersible resin in the white ink is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to the content of the pigment in the white ink of 1 part by mass. When two or more types of water-dispersible resins are used, the content of the water-dispersible resins mentioned above is the total content thereof. The same applies to the content of the pigment mentioned above.

[0075] The white ink may contain other components as appropriate, such as a pH adjuster and a preservative.

[0076] The method for producing the white ink is not particularly limited, and the ink can be produced by any known method. For example, all of the components are added to a stirrer such as a Three-One Motor all at once or in portions, and dispersed, and if desired, the mixture is passed through a filter such as a membrane filter to obtain an ink.

[0077] The white ink can be used as a water-based inkjet ink for textile printing.

[0078] From the viewpoint of storage stability of the ink, the pH of the white ink is preferably 7.0 to 10.0, and more preferably 7.5 to 9.0.

[0079] The viscosity of the white ink can be adjusted as appropriate, but from the standpoint of jetting properties, for example, the viscosity at 23° C. is preferably 1 to 30 mPa·s.

[0080] <Color ink> As the color ink, a color ink having a Young's modulus of a dried coating film of 3.0 MPa or less can be used. Here, the dried coating film of the color ink refers to a dried coating film obtained by diluting the color ink with ion-exchanged water so that the total solid content of the pigment and resin in the color ink is 20% by mass, pouring this diluted solution into a PTFE (polytetrafluoroethylene) petri dish so that the film thickness after drying will be 0.4 mm, and heating and drying it in a thermostatic chamber at 70°C for 60 minutes, at 120°C for 20 minutes, and at 160°C for 10 minutes. The Young's modulus of a dried coating film can be measured using a test piece obtained by cutting the dried coating film into a No. 8 dumbbell shape as specified in JIS K6251. Specifically, a TENSILON universal testing machine ("RTG-1250" (trade name) manufactured by A&D Co., Ltd.) is used to measure the stress-strain (elongation) curve of the test piece under conditions of a tensile speed of 500 mm / min and a chuck distance of 20 mm. The stress at an elongation rate of 10% on the obtained stress-strain curve is defined as the Young's modulus [MPa] of the test piece. The film thickness of the dried coating film can be determined by actual measurement using a micrometer ("MDH-25PX" (trade name) manufactured by Mitutoyo Corporation).

[0081] The Young's modulus of the dried coating film of the color ink can be adjusted by adjusting the type and amount of components in the color ink. For example, it can be adjusted by adjusting the Young's modulus of the resin, such as a water-dispersible resin, in the color ink, the content of the resin, such as a water-dispersible resin, in the color ink, or the mass ratio of the pigment to the water-dispersible resin in the color ink. The Young's modulus of the dried coating film of the color ink may be adjusted by combining several methods.

[0082] The Young's modulus of the dried coating film of the color ink is preferably 3.0 MPa or less, more preferably 2.0 MPa or less, and even more preferably 1.0 MPa or less. The Young's modulus of the dried coating film of the color ink is preferably 0.1 MPa or more, and more preferably 0.3 MPa or more. The Young's modulus of the dried coating film of the color ink is, for example, preferably 0.1 to 3.0 MPa, more preferably 0.3 to 2.0 MPa, and even more preferably 0.3 to 1.0 MPa or more.

[0083] Examples of color inks include magenta ink, cyan ink, yellow ink, black ink, and other inks other than white ink. The color ink preferably contains, for example, a coloring material and a resin, such as a polymer dispersant or a water-dispersible resin, which will be described later.

[0084] The color ink may contain, as a colorant, a pigment, a dye, or a combination thereof, and preferably contains a pigment.

[0085] The pigment preferably includes a non-white pigment.

[0086] Non-white pigments include organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, and dye lake pigments, as well as inorganic pigments such as carbon black and metal oxides. Azo pigments include soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments. Phthalocyanine pigments include metal phthalocyanine pigments and metal-free phthalocyanine pigments. 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). Carbon blacks include furnace carbon black, lamp black, acetylene black, and channel black. Metal oxides include titanium oxide and zinc oxide. These pigments may be used alone or in combination.

[0087] From the viewpoints of ejection stability and storage stability, the average particle size of the pigment particles in the ink 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 in the particle size distribution measured by dynamic light scattering.

[0088] A self-dispersing pigment may be blended as the pigment. A self-dispersing pigment is a pigment in which a hydrophilic functional group has been introduced onto the pigment surface by chemical or physical treatment. The hydrophilic functional group introduced into the self-dispersing pigment is preferably ionic, and by charging the pigment surface anionically or cationically, the pigment particles can be stably dispersed in water due to electrostatic repulsion. Preferred anionic functional groups include sulfonic acid groups, carboxy groups, carbonyl groups, hydroxy groups, and phosphonic acid groups. Preferred cationic functional groups include quaternary ammonium groups and quaternary phosphonium groups.

[0089] These hydrophilic functional groups may be bonded directly to the pigment surface or via other atomic groups. Examples of such other atomic groups include, but are not limited to, alkylene groups, phenylene groups, and naphthylene groups. Examples of methods for treating the pigment surface include diazotization, sulfonation, hypochlorous acid treatment, humic acid treatment, and vacuum plasma treatment.

[0090] Preferred examples of self-dispersing pigments that can be used include the CAB-O-JET series manufactured by Cabot Corporation, such as "CAB-O-JET200," "CAB-O-JET300," "CAB-O-JET250C," "CAB-O-JET260M," "CAB-O-JET270," and "CAB-O-JET450C," and products manufactured by Orient Chemical Industries Co., Ltd., such as "BONJET BLACK CW-1," "BONJET BLACK CW-2," "BONJET BLACK CW-3," and "BONJET BLACK CW-4" (all trade names). As the pigment, a microencapsulated pigment in which the pigment is coated with a resin may be used.

[0091] A pigment dispersion in which the pigment is dispersed in advance with a pigment dispersant may be used. Commercially available pigment dispersions dispersed with a pigment dispersant include, for example, the HOSTAJET series manufactured by Clariant and the FUJI SP series manufactured by Fuji Pigment Co., Ltd. A pigment dispersion dispersed with a pigment dispersant described below may also be used.

[0092] As the dye, water-soluble dyes and water-soluble dyes made water-soluble by reduction or the like can be preferably used from among basic dyes, acid dyes, direct dyes, soluble vat dyes, acid mordant dyes, mordant dyes, reactive dyes, vat dyes, sulfur dyes, etc. Also preferably used are disperse dyes such as azo-based, anthraquinone-based, azomethine-based, and nitro-based dyes. These may be used alone or in combination.

[0093] The coloring materials may be used alone or in combination of two or more.

[0094] From the viewpoints of print density and ink viscosity, the content of the color material is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, and even more preferably 2 to 7% by mass, of the total amount of color ink. When two or more color materials are used, the content of the color materials mentioned above is the total content thereof.

[0095] When a pigment is used as a coloring material in a color ink, a pigment dispersant, typically a polymer dispersant or a surfactant-type dispersant, can be used to stably disperse the pigment in the color ink.

[0096] The pigment dispersant can be selected from those described above for the white ink. When a pigment dispersant is used, the amount of pigment dispersant blended in the color ink varies depending on the type and is not particularly limited, but in general, the mass ratio of the active ingredient (pigment concentration) to the pigment is preferably 0.005 to 0.5.

[0097] The color ink preferably contains water as an aqueous solvent, and the main solvent may be water. The water is not particularly limited, but is preferably one that contains as few ionic components as possible. In particular, from the viewpoint of ink storage stability, it is preferable that the content of polyvalent metal ions such as calcium is low. Examples of water that can be used include ion-exchanged water, distilled water, and ultrapure water. From the viewpoint of adjusting the ink viscosity, the water content is preferably 20% by mass to 80% by mass, and more preferably 30% by mass to 70% by mass, based on the total amount of the color ink.

[0098] The color ink may contain a water-soluble organic solvent. As the water-soluble organic solvent, an organic compound that is liquid at room temperature and dissolves in water may be used, and it is preferable to use a water-soluble organic solvent that is uniformly miscible with an equal volume of water at 20°C under 1 atmosphere. The water-soluble organic solvent can be selected from those described above for the treatment liquid. These water-soluble organic solvents may be used alone or in combination of two or more kinds as long as they form a single phase with water. The content of the water-soluble organic solvent in the color ink is preferably 5 to 50% by mass, and more preferably 10 to 30% by mass, based on the total amount of the color ink. When two or more water-soluble organic solvents are used, the content of the water-soluble organic solvents mentioned above is the total content thereof.

[0099] The color ink preferably contains a surfactant.

[0100] The surfactant may be any of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, with nonionic surfactants being preferred. In addition, either low-molecular-weight surfactants or polymeric surfactants may be used.

[0101] The HLB value of the surfactant is preferably 5-20, and more preferably 10-18. The surfactant may be selected from those described above for the treatment liquid, and among these, acetylene-based surfactants such as acetylene glycol-based surfactants are preferably used.

[0102] The surfactants may be used alone or in combination of two or more. The content of the surfactant is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, based on the total amount of the color ink. When two or more surfactants are used, the content of the surfactants mentioned above is the total content thereof.

[0103] The color ink may include a water-dispersible resin.

[0104] The water-dispersible resin is preferably resin particles that can be dispersed in an aqueous solvent. The water-dispersible resin can be blended into the ink, for example, as an oil-in-water resin emulsion. The water-dispersible resin may be a self-emulsifying resin in which a hydrophilic component is introduced to stably disperse it in water, or may be a resin that becomes water-dispersible by the use of an external emulsifier.

[0105] From the viewpoint of inkjet ejection properties, the average particle diameter of the water-dispersible resin 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 diameter of the water-dispersible resin may be in the range of 10 nm to 300 nm. Here, the average particle diameter of the resin is the average particle diameter on a volume basis, and is a value measured by a light scattering method.

[0106] As the type of water-dispersible resin, it is preferable to use a resin that forms a transparent coating film. The water-dispersible resin can be selected from those described above for the white ink.

[0107] The water-dispersible resin may be anionic, cationic, nonionic or amphoteric, with anionic water-dispersible resins being preferred. The anionic water-dispersible resin may be one in which anionic groups are present on the particle surface, such as a self-emulsifying resin, or one in which the surface of the resin particles has been surface-treated by attaching an anionic dispersant to the surface. Representative anionic groups include carboxyl groups, sulfo groups, and phosphate groups. Examples of the anionic dispersant include anionic surfactants.

[0108] These water-dispersible resins may be used alone or in combination of two or more. The content (solid content) of the water-dispersible resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on the total amount of the color ink. The content (solid content) of the water-dispersible resin is preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the color ink. The content (solid content) of the water-dispersible resin is preferably 1 to 30% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass, based on the total amount of the color ink. When two or more water-dispersible resins are used, the content of the water-dispersible resins mentioned above is the total content thereof.

[0109] The color ink preferably contains a pigment and a water-dispersible resin. When the color ink contains a pigment and a water-dispersible resin, the ratio of the pigment and the water-dispersible resin is not particularly limited. From the viewpoint of more effectively suppressing cracking of ink images after washing, the mass ratio of the water-dispersible resin to the pigment in the color ink (water-dispersible resin / pigment) is preferably 2.5 or more. On the other hand, from the viewpoint of ejection performance, the mass ratio of the water-dispersible resin to the pigment in the color ink (water-dispersible resin / pigment) is preferably 5.0 or less, more preferably 4.0 or less. The mass ratio of the water-dispersible resin to the pigment in the color ink (water-dispersible resin / pigment) is preferably 2.5 to 5.0, more preferably 2.5 to 4.0. When two or more water-dispersible resins are used, the content of the water-dispersible resin in the above-mentioned mass ratio of the water-dispersible resin to the pigment is the total content, and the same applies to the content of the pigment.

[0110] The color ink preferably contains a crosslinking agent. When a crosslinking agent is contained, the color ink film becomes stronger, and cracking of the ink image after washing tends to be more easily suppressed. In addition, the image density of the color ink can be more easily increased.

[0111] Examples of the crosslinking agent include carbodiimide compounds, isocyanate compounds, and oxazoline compounds. Commercially available carbodiimide compounds include, for example, "Carbodilite V-02" manufactured by Nisshinbo Chemical Inc. Commercially available oxazoline compounds include, for example, "Epocross K2030E" manufactured by Nippon Shokubai Co., Ltd. Commercially available isocyanate compounds include, for example, "Elastron BN69" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0112] The crosslinking agent may be used alone or in combination of two or more. The content of the crosslinking agent is preferably 0.1% by mass or more, and more preferably 0.2% by mass or more, relative to the total amount of the color ink. The content of the crosslinking agent is preferably 5% by mass or less, and more preferably 2% by mass or less, relative to the total amount of the color ink. The content of the crosslinking agent is preferably 0.1 to 5% by mass, and more preferably 0.2 to 2% by mass, relative to the total amount of the color ink. When two or more crosslinking agents are used, the content of the crosslinking agents mentioned above is the total content thereof.

[0113] The color ink may contain other components as appropriate, such as a pH adjuster and a preservative.

[0114] The method for producing the color ink is not particularly limited, and the ink can be produced by any known method. For example, all the components are added to a mixer such as a Three-One Motor all at once or in portions, and dispersed, and if desired, the mixture is passed through a filter such as a membrane filter to obtain an ink.

[0115] The color inks can be used as water-based textile inkjet inks.

[0116] The pH of the color ink is preferably 7.0 to 10.0, more preferably 7.5 to 9.0, from the viewpoint of storage stability of the ink.

[0117] The viscosity of the color ink can be adjusted as appropriate, but from the viewpoint of ejection properties, for example, the viscosity at 23° C. is preferably 1 to 30 mPa·s.

[0118] <Method of manufacturing printed items> A method for producing a printed textile according to one embodiment can include the steps of applying the treatment liquid to a cloth by an inkjet method, applying the white ink by a wet-on-wet method by an inkjet method to the cloth to which the treatment liquid has been applied, and applying the color ink by a wet-on-wet method by an inkjet method to the cloth to which the white ink has been applied.

[0119] The treatment liquid, white ink, and color inks are preferably applied to the fabric by inkjet printing, which is a printing method that allows for easy and flexible image formation on demand without contacting the substrate. The inkjet method is not particularly limited, and may be any of a piezoelectric method, an electrostatic method, a thermal method, etc. When an inkjet printing device is used, it is preferable to eject droplets of the treatment liquid or ink from an inkjet head based on a digital signal, and to allow the ejected droplets to adhere to the fabric.

[0120] The process of applying the treatment liquid to the fabric by the inkjet method will be described. The area to which the treatment liquid is applied may be an area of ​​the same shape as the white ink image, a wider area that includes the shape of the white ink image, or the entire surface of the fabric. It is preferable that the treatment liquid application area, the white ink application area, and the color ink application area at least partially overlap.

[0121] The amount of treatment solution applied to the fabric is 5 to 200 g / m 2 is preferable, and 10 to 100 g / m 2 is preferable, and 15 to 80 g / m 2 is more preferred.

[0122] The process of applying white ink to the cloth to which the treatment liquid has been applied using a wet-on-wet method by an inkjet system will be described. The area to which the white ink is applied may be an area of ​​the same shape as the image made of color inks, a wider area including the shape of the image made of color inks, or the entire surface of the fabric. It is preferable that the white ink is applied so that the application area overlaps at least partially with the application area of ​​the treatment liquid. It is preferable that the application area of ​​the treatment liquid, the application area of ​​the white ink, and the application area of ​​the color inks at least partially overlap.

[0123] The white ink is preferably applied to the fabric to which the treatment liquid has been applied by a wet-on-wet method. The white ink is preferably applied without completely removing moisture from the fabric to which the treatment liquid has been applied. Preferably, the white ink can be applied while the fabric to which the treatment liquid has been applied remains wet. For example, it is preferable to apply the white ink to the fabric without performing a drying process such as heat drying after applying the treatment liquid to the fabric. The temperature of the fabric surface after applying the treatment liquid and before applying the white ink is preferably 40°C or lower, more preferably 35°C or lower. After applying the treatment liquid, the white ink is preferably applied when the amount of volatile matter remaining on the fabric from the treatment liquid is 90% by mass or higher. The time between applying the treatment liquid to the fabric and applying the white ink is preferably 0.1 to 200 seconds.

[0124] The amount of white ink applied to the fabric is not particularly limited, but may be, for example, 80 to 400 g / m 2 is preferable, and 120 to 250 g / m 2 is more preferred.

[0125] A process of applying color ink to a cloth to which white ink has been applied, using an inkjet method in a wet-on-wet manner, will be described. It is preferable that the color ink is applied so that the application area overlaps at least partially with the application area of ​​the white ink. It is also preferable that the application area of ​​the treatment liquid, the application area of ​​the white ink, and the application area of ​​the color inks overlap at least partially.

[0126] The color ink is preferably applied to the fabric to which the white ink has been applied by a wet-on-wet method. The color ink is preferably applied without completely removing moisture from the fabric to which the white ink has been applied. Preferably, the color ink can be applied while the fabric to which the white ink has been applied remains wet. For example, it is preferable to apply the color ink to the fabric after applying the white ink to it without performing a drying process such as heat drying. The temperature of the fabric surface after applying the white ink and before applying the color ink is preferably 40°C or lower, more preferably 35°C or lower. After applying the white ink, it is preferable to apply the color ink when the remaining volatile content of the white ink on the fabric is 90% by mass or higher. The time between applying the white ink to the fabric and applying the color ink is preferably 0.1 to 200 seconds.

[0127] The amount of color ink applied to the fabric is not particularly limited, but may be, for example, 1 to 100 g / m 2 is preferable, and 5 to 50 g / m 2 is more preferred.

[0128] It should be noted that one type of color ink may be applied, or two or more types of color ink may be applied.

[0129] The step of applying the treatment liquid, the step of applying the white ink, and the step of applying the color inks may be performed by separate printing devices, or may be performed by using a single printing device. For example, two printing devices may be used, with the step of applying the treatment liquid being performed by one printing device and the step of applying the white ink and the step of applying the color inks being performed by the other printing device.

[0130] The method for producing a printed item preferably includes a step of heat treating the fabric after applying the color ink. The heat treatment temperature can be appropriately selected depending on the material of the fabric, etc. The heat treatment temperature is, for example, preferably 100° C. or higher, more preferably 150° C. or higher. From the viewpoint of reducing damage to the fabric, the heat treatment temperature is preferably 200° C. or lower. The heating device is not particularly limited, but for example, a heat press, a roll heater, a hot air device, an infrared lamp heater, or the like can be used. The heat treatment time may be appropriately set depending on the heating method, etc., and is, for example, preferably 1 second to 10 minutes, and may be 5 seconds to 5 minutes.

[0131] After applying the color ink to the fabric, a step of applying a post-treatment liquid may be provided. After applying the color ink, a step of heating the fabric may be provided, and then the post-treatment liquid may be applied. After applying the color ink, the post-treatment liquid may be applied by a wet-on-wet method. Furthermore, after applying the post-treatment liquid, a step of heating the fabric may be provided.

[0132] <Ink set> One embodiment provides an inkjet textile printing ink set including a treatment liquid containing a flocculant, a white ink having a charge density of 30 μeq / g or more, and a color ink having a Young's modulus of a dried coating film of 3.0 MPa or less. As the treatment liquid, white ink, and color ink, the treatment liquid, white ink, and color ink that can be used in the above-mentioned method for producing a printed item can be used, respectively. The inkjet textile printing ink set may further include a post-treatment liquid and the like. [Example]

[0133] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0134] <Production of processing solution> The formulation of treatment liquid U-1 is shown in Table 1. The raw materials shown in Table 1 were mixed in the blending ratio shown in Table 1, and coarse particles were removed using a membrane filter with a pore size of 3 μm to obtain treatment liquid U-1.

[0135] [Table 1]

[0136] Details of the materials listed in Table 1 are given below. (flocculant) Calcium chloride: Fujifilm Wako Pure Chemical Industries, Ltd., active ingredient 100% by mass (Water-soluble organic solvent) 1,4-Butanediol: Fujifilm Wako Pure Chemical Industries, Ltd. (surfactant) Olfine E1010: Acetylenic surfactant, manufactured by Nissin Chemical Industry Co., Ltd., active ingredient 100% by mass

[0137] <White ink production> The formulations of white inks W-1 to W-8 are shown in Tables 2 and 3. The blending ratios of raw materials in Tables 2 and 3 include solvents and the like when they are contained in the materials. The materials shown in Tables 2 and 3 were mixed according to the blending ratios shown in Tables 2 and 3, and coarse particles were removed using a membrane filter with a pore size of 3 μm to obtain a white ink.

[0138] [Table 2]

[0139] [Table 3]

[0140] Details of the materials listed in Tables 2 and 3 are given below.

[0141] (Pigment dispersion) White pigment dispersion: Obtained by the following method, pigment content 40% by mass

[0142] (Water dispersible resin) DAOTAN TW6490 / 35WA: Water-dispersible polyurethane resin (water-based resin emulsion), manufactured by Daicel Allnex Corporation, solid content 35% by mass DAOTAN TW6460 / 35WA: Water-dispersible polyurethane resin (water-based resin emulsion), manufactured by Daicel Allnex Corporation, solid content 35% by mass DAOTAN TW6450 / 30WA: Water-dispersible polyurethane resin (water-based resin emulsion), manufactured by Daicel Allnex Corporation, solid content 30% by mass NeoRez R986: Water-dispersible polyurethane resin (water-based resin emulsion), manufactured by DSM, solids content 25% by mass Movinyl 6763: Water-dispersible polyurethane resin (water-based resin emulsion), manufactured by Japan Coating Resin Co., Ltd., solid content 35% by mass

[0143] (Water-soluble organic solvent) 1,4-Butanediol: Fujifilm Wako Pure Chemical Industries, Ltd. (surfactant) Olfine E1010: Acetylenic surfactant, manufactured by Nissin Chemical Industry Co., Ltd., active ingredient 100% by mass

[0144] <Production of White Pigment Dispersion> 400 g of titanium dioxide "R-21N" (manufactured by Sakai Chemical Industry Co., Ltd.) as a white pigment and 20 g (5 g of active ingredient) of "Demol EP" (manufactured by Kao Corporation) as a pigment dispersant were mixed with 580 g of ion-exchanged water, and the mixture was dispersed with 0.5 mm diameter zirconia beads using a bead mill (manufactured by Shinmaru Enterprises Co., Ltd., DYNO-MILL KDL A type) at a filling rate of 80% and a residence time of 5 minutes, yielding a white pigment dispersion (pigment content 40% by mass).

[0145] <Color ink manufacturing> The formulations of color inks K-1 to K-12 are shown in Tables 4 and 5. The blending ratios of raw materials in the tables include solvents and other ingredients when they are included in the materials. The materials shown in Tables 4 and 5 were mixed according to the blending ratios shown in Tables 4 and 5, and coarse particles were removed using a membrane filter with a pore size of 3 μm to obtain color inks.

[0146] [Table 4]

[0147] [Table 5]

[0148] Details of the materials listed in Tables 4 and 5 are provided below.

[0149] (Pigment dispersion) Black pigment dispersion: Obtained by the following method, pigment content 20% by mass (Water dispersible resin) Superflex 460: Water-dispersible polyurethane resin (aqueous resin emulsion), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 38% by mass UW-1005D-C1: Water-dispersible polyurethane resin (water-based resin emulsion), manufactured by Ube Industries, Ltd., solid content 30% by mass UW-1527DF: Water-dispersible polyurethane resin (water-based resin emulsion), manufactured by Ube Industries, Ltd., solid content 30% by mass Adeka Bontiter HUX-370: Water-dispersible acrylic resin (water-based resin emulsion), manufactured by ADEKA Corporation, 33% by mass

[0150] (Crosslinking agent) Carbodilite V-02: Carbodiimide compound, manufactured by Nisshinbo Chemical Inc., solid content 40% by mass Elastron BN69: Isocyanate compound, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 40% by mass Epocross K2030E: Oxazoline compound, manufactured by Nippon Shokubai Co., Ltd., solid content 40% by mass

[0151] (surfactant) Olfine E1010: Acetylenic surfactant, manufactured by Nissin Chemical Industry Co., Ltd., active ingredient 100% by mass

[0152] (Water-soluble organic solvent) 1,4-Butanediol: Fujifilm Wako Pure Chemical Industries, Ltd.

[0153] <Production of Black Pigment Dispersion> 200 g of "#960" (manufactured by Mitsubishi Chemical Corporation) as a black pigment and 50 g of DISPERBYK-102 (a polymer dispersant manufactured by BYK Japan Co., Ltd.) as a pigment dispersant were mixed with 800 g of ion-exchanged water, and the mixture was dispersed using a bead mill (manufactured by Shinmaru Enterprises Co., Ltd., DYNO-MILL KDL A type) with 0.5 mm diameter zirconia beads at a filling rate of 60% and a residence time of 2 minutes to obtain a black pigment dispersion (pigment content 20% by mass).

[0154] <Method for measuring charge density> The charge density of treatment liquid U-1 in Table 1, the charge density of each white ink in Tables 2 and 3, and the charge density of the water-dispersible resin used in the white inks in Tables 2 and 3 were measured by the streaming potential method as follows. A colloidal particle charge meter (Model CAS, manufactured by AFG ANALYTIC GmbH) was used to measure the charge density. (Charge density of treatment liquid and charge density of white ink) The white ink and treatment solution to be measured were each diluted 100-fold with ion-exchange water and used as samples. The titration was performed using the titration solution described below. The reaction endpoint, at which the streaming potential reached 0 V, was measured. The total charge of the diluted treatment solution and the total charge of the diluted white ink were calculated from the amount of titration solution used up to the reaction endpoint. The charge density (μeq / g) of the white ink was calculated from the total charge of the white ink per unit of active ingredient in the diluted white ink. Similarly, the charge density (μeq / g) of the treatment solution was calculated from the total charge of the treatment solution per unit of active ingredient in the diluted treatment solution. For the white ink, a 0.0025N polydiallyldimethylammonium chloride (polyDADMAC) solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the titration solution, and for the treatment solution, a 0.0025N polyvinyl potassium sulfate (PVSK) solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used. (Charge density of water-dispersible resin used in white ink) The aqueous resin emulsion of the water-dispersible resin to be measured was diluted with water to a solids content of 0.05% by mass, and the resulting diluted solution was used as a sample. This was titrated with a 0.0025N polydiallyldimethylammonium chloride (polyDADMAC) solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and the reaction endpoint, at which the streaming potential of the diluted solution reached 0 V, was measured. The total charge of the diluted solution was calculated from the amount of polyDADMAC solution used up to the reaction endpoint. The charge density (μeq / g) of the water-dispersible resin was determined by dividing the total charge of this diluted solution by the amount of solids contained in the diluted solution.

[0155] <Young's modulus of dried color ink coating> The Young's modulus of the dried coating film of each color ink in Tables 4 and 5 was obtained as follows. The color ink was diluted with ion-exchange water so that the total solid content of the pigment and resin in the ink was 20% by mass. The diluted solution was poured into a PTFE (polytetrafluoroethylene) petri dish so that the dried film thickness would be 0.4 mm. The ink was then heated and dried in a thermostatic chamber at 70°C for 60 minutes, 120°C for 20 minutes, and 160°C for 10 minutes to obtain a dried ink coating film. The resulting dried coating film was cut into a dumbbell No. 8 shape as specified in JIS K6251 to obtain test specimens. The stress-strain (elongation) curve of the test specimen was measured using a TENSILON universal testing machine (A&D Co., Ltd., "RTG-1250") at a tensile speed of 500 mm / min with a chuck distance of 20 mm. The stress at 10% elongation in the obtained stress-strain curve was taken as the Young's modulus [MPa] of the test specimen. The thickness of the dried coating film was determined by actual measurement using a micrometer ("MDH-25M" manufactured by Mitutoyo Corporation).

[0156] <Production of printed items> Tables 6 and 7 show the treatment liquids, white inks and color inks used in the printed products of Examples 1 to 17 and Comparative Examples 1 and 2. In Examples 1 to 17 and Comparative Examples 1 and 2, a black 100% cotton T-shirt "Printstar 085-cvt" (manufactured by TMS Co., Ltd.) was used as the substrate. In addition, two inkjet printers (Mastermind textile printer "MMP-8130") were prepared, and the treatment liquid was introduced into the first printer (hereinafter sometimes referred to as "Printer 1"), and white ink and color ink were introduced into the second printer (hereinafter sometimes referred to as "Printer 2"). Printed items of Examples 1 to 17 and Comparative Examples 1 and 2 were produced according to the following steps 1 to 4.

[0157] Process 1 In step 1, the printer 1 into which the treatment liquid is introduced is used to apply the treatment liquid onto the substrate in an amount of 50 g / m. 2 The treatment liquid was applied to the entire area of ​​100 mm x 200 mm so as to achieve the following. Process 2 In step 2, printer 2 was used to apply white ink by a wet-on-wet method to the substrate to which the treatment liquid had been applied. In this step 2, the amount of white ink applied was 200 g / m2 onto the 100 mm x 200 mm area to which the treatment liquid had been applied. 2 A 100 mm x 200 mm white solid image was printed so that the image was as follows: Process 3 In step 3, color inks were applied by a wet-on-wet method to the substrate to which white had been applied using printer 2. In this step, the amount of color ink applied was 20 g / m onto a 100 mm x 200 mm area to which the treatment liquid and white ink had been applied, i.e., onto a 100 mm x 200 mm white solid image. 2 A 100 mm x 200 mm black solid image was printed so that the image was as follows: Process 4 In step 4, the printed T-shirt was heat treated at 160° C. for 120 seconds using a Hotronix Fusion heat press (manufactured by Stahls Hotronix).

[0158] <Evaluation> The following evaluations were made. The evaluation of "image density of color ink" and "cracking of ink image after washing" below were made using printed textiles obtained by carrying out steps 1 to 4. The evaluation of "concealing ability with white ink" below was made using a white ink coating film obtained by carrying out the heat treatment of step 4 after step 2 without carrying out step 3. The results are shown in Tables 6 and 7.

[0159] (Opacity with white ink) The L* value of the white solid image obtained in step 2 was measured using a spectrophotometer X-Rite eXact and evaluated according to the following evaluation criteria. A:90≦L* B:85≦L*<90 D:L*<85

[0160] (Color ink image density) The OD values ​​of the resulting printed textiles were measured using a spectrophotometer, X-Rite eXact, and evaluated according to the following criteria. A: 1.00≦OD B: 0.85≦OD<1.00 C: 0.75≦OD<0.85 D:OD<0.75

[0161] (Ink image cracking after washing) The resulting printed fabric was cut into a 25mm x 40mm piece to prepare a test specimen. A 50mL container was charged with the test specimen, a 10mm diameter stainless steel ball, and wash water (0.1% by mass aqueous solution of synthetic laundry detergent) heated to 50°C, and the test specimen was stirred for 10 minutes at a frequency of 60Hz using a high-speed ball mill agitator / mixer, a rocking mill. After stirring, the test specimen was dried in an environment of 23°C for 3 hours, and then visually inspected for cracks in the ink image and evaluated according to the following criteria. A: No cracks are visible B: Slight cracks have occurred D: Significant cracks

[0162] [Table 6]

[0163] [Table 7]

[0164] As shown in each table, Examples 1 to 17 exhibited excellent hiding power with white ink, and also showed excellent results in the evaluation of color ink image density and the evaluation of cracking of ink images after washing.

Claims

1. applying a treatment liquid containing a flocculant to a fabric by an inkjet method; applying a white ink having a charge density of 30 μeq / g or more to the cloth to which the treatment liquid has been applied by a wet-on-wet method using an inkjet system; and applying a color ink having a Young's modulus of a dry coating film of 3.0 MPa or less to the cloth to which the white ink has been applied by a wet-on-wet method using an inkjet system, The method for producing a printed item, wherein the color ink contains a crosslinking agent.

2. 2. The method for producing a printed item according to claim 1, wherein the color ink contains a pigment and a water-dispersible resin, and a mass ratio of the water-dispersible resin to the pigment (water-dispersible resin / pigment) is 2.5 to 5.

0.

3. 3. The method for producing a printed item according to claim 1, wherein the white ink comprises a water-dispersible resin A having a charge density of 55 μeq / g or less and a water-dispersible resin B having a charge density of 75 μeq / g or more.

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