Manufacturing method for printed materials

Abstract

To provide a method of producing a printed article capable of producing a printed article excellent in concealment to a substrate, and excellent in productivity also.SOLUTION: A method of printed article includes: applying a pretreatment liquid containing a flocculant, water, and a surface active agent to a cloth; and applying a white ink containing a white pigment and water to the cloth by an inkjet method after applying the pretreatment liquid, where the surface tension of the white ink at 0.05 Hz is 33-39 mN / m, the surface tension of the white ink at 10 Hz is 40 mN / m or higher, the specific gravity of the pretreatment liquid is higher than a specific gravity of the white ink, and the application of the white ink is performed within 100 seconds from application of the pretreatment liquid and by a wet-on 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, inkjet 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] When printing on dark-colored fabric using a pigment ink, for example, the image on the printed item may be affected by the background color of the fabric, preventing good color development. Therefore, efforts are being made to improve the hiding power of the substrate. Patent Document 1 describes a method in which a pretreatment liquid containing a polyvalent metal salt is applied to a dark colored cloth such as black, and then a white ink is printed to form a white image, and a desired image is then formed on top of that. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-30014 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of an embodiment of the present invention is to provide a method for producing a printed item that is capable of producing a printed item that has excellent hiding power for a substrate and is also excellent in productivity. [Means for solving the problem]

[0006] An embodiment of the present invention relates to a method for producing a printed textile, comprising: applying a pretreatment liquid containing a flocculant, water, and a surfactant to a fabric; and, after the application of the pretreatment liquid, applying a white ink containing a white pigment and water to the fabric by an inkjet method, wherein the surface tension of the white ink at 0.05 Hz is 33 to 39 mN / m and the surface tension of the white ink at 10 Hz is 40 mN / m or more, the specific gravity of the pretreatment liquid is higher than that of the white ink, and the application of the white ink is carried out within 100 seconds after the application of the pretreatment liquid by a wet-on-wet method. [Effects of the Invention]

[0007] According to an embodiment of the present invention, it is possible to produce a printed item that has excellent hiding power for a substrate, and it is also possible to provide a method for producing a printed item that is excellent in productivity. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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.

[0009] A method for producing a printed textile according to one embodiment includes applying a pretreatment liquid containing a flocculant, water, and a surfactant to a fabric, and after the application of the pretreatment liquid, applying a white ink containing a white pigment and water to the fabric by an inkjet method, wherein the surface tension of the white ink at 0.05 Hz is 33 to 39 mN / m and the surface tension of the white ink at 10 Hz is 40 mN / m or more, the specific gravity of the pretreatment liquid is higher than that of the white ink, and the application of the white ink is carried out within 100 seconds after the application of the pretreatment liquid by a wet-on-wet method.

[0010] According to the method for producing a printed item of one embodiment, a printed item having excellent hiding power for a substrate can be produced, and productivity is also excellent.

[0011] When a white image is formed by a so-called wet-on-wet method in which a pretreatment liquid is applied and then white ink is printed without a drying step, and the pretreatment liquid is not dried, it is preferable that the amount of pretreatment liquid applied is not too large in order to improve fixation by the white ink penetrating into the fabric and exerting an anchoring effect. However, if the amount of pretreatment liquid applied is small, the white ink may easily penetrate into the fabric, resulting in a decrease in hiding power.

[0012] The pretreatment liquid penetrates and spreads into the fabric over time, and the amount of pretreatment liquid available to react with the white ink per unit area tends to decrease over time. The surface tension of the white ink at 0.05 Hz is the surface tension in a nearly static state, and if this value is 33 to 39 mN / m, and the time between the application of the pretreatment liquid and the application of the white ink is 100 seconds or less, the white ink can react with a larger amount of the pretreatment liquid, which can improve hiding power. When the surface tension of the white ink at 10 Hz is 40 mN / m or more, penetration of the ink into the fabric when it lands, which is a dynamic state, can be suppressed, and the hiding power can be improved. Furthermore, if the specific gravity of the pretreatment liquid is higher than that of the white ink, the unreacted white ink tends to be prevented from penetrating together with the pretreatment liquid or to be less likely to sink below the pretreatment liquid, which can prevent the white ink from penetrating into the fabric and improve hiding power.

[0013] Furthermore, by applying the white ink within 100 seconds after applying the pretreatment liquid, the time required for manufacturing can be shortened and productivity can be improved.

[0014] In one embodiment, a method for producing a printed textile preferably includes applying a pretreatment liquid containing a flocculant, water, and a surfactant to a fabric, and, after the application of the pretreatment liquid, applying a white ink containing a white pigment and water to the fabric by an inkjet method. The method for producing a printed textile may further include applying a color ink by a wet-on-wet method after the white ink. The fabric, the pretreatment liquid, the white ink, and the color ink will be described below.

[0015] <Cloth> The method for producing a printed item according to one embodiment can be preferably used for printing on fabric. 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.

[0016] <Pretreatment liquid> The pretreatment liquid preferably contains a flocculant.

[0017] The flocculant may be a component that has the effect of flocculating the coloring material in the ink on the fabric substrate. When the white ink is then applied to the fabric to which the pretreatment liquid has been applied, the pigment in the white ink aggregates on the fabric, thereby increasing the image density of the white ink and preventing image bleeding. Specific examples of the flocculant include metal salts, cationic polymers, organic acids, and the like, or combinations of these. Polyvalent metal salts are preferred as the metal salts. The flocculant is preferably a metal salt, and from the viewpoint of the specific gravity of the pretreatment liquid, a polyvalent metal salt is more preferable. The total amount of the flocculant, in terms of the amount of active ingredients, is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to the total amount of the pretreatment liquid. The total amount of the flocculant, in terms of the amount of active ingredients, is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, relative to the total amount of the pretreatment liquid. The total amount of the flocculant, in terms of the amount of active ingredients, is preferably 1 to 40% by mass, preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and even more preferably 15 to 25% by mass, relative to the total amount of the pretreatment liquid.

[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 - and the like. Specific examples of polyvalent metal salts include calcium chloride, calcium nitrate, magnesium nitrate, copper nitrate, calcium acetate, and magnesium acetate. Among these, calcium chloride, calcium nitrate, and magnesium nitrate are preferred, with calcium nitrate being more preferred, from the viewpoint of making it easier to increase the specific gravity of the pretreatment liquid to be higher than the specific gravity of the white ink. By using these polyvalent metal salts, it is possible to increase the specific gravity of the pretreatment liquid even higher than the specific gravity of the white ink, which contains a high blend amount of an inorganic pigment such as titanium oxide as a white pigment.

[0019] These polyvalent metal salts may be used alone or in combination of two or more. From the viewpoint of the specific gravity of the pretreatment liquid, the amount of the polyvalent metal salt in terms of the active ingredient is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total amount of the pretreatment liquid. The amount of the polyvalent metal salt in terms of the active ingredient is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, based on the total amount of the pretreatment liquid. The amount of the polyvalent metal salt in terms of the active ingredient is preferably 1 to 40% by mass, preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and even more preferably 15 to 25% by mass, based on the total amount of the pretreatment liquid. 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 may be either a cationic water-soluble resin or a cationic water-dispersible resin, or a combination of these may be used.

[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).

[0023] 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.

[0024] Examples of cationic water-dispersible resins include urethane resins, (meth)acrylic resins, styrene / (meth)acrylic resins, polyester resins, olefin resins, vinyl chloride resins, vinyl acetate resins, melamine resins, amide resins, ethylene-vinyl chloride copolymer resins, styrene-maleic anhydride copolymer resins, vinyl acetate-(meth)acrylic copolymer resins, vinyl acetate-ethylene copolymer resins, and composite resins thereof. These resins may be given a positive surface charge by introducing a cationic functional group into them or by surface treatment with a cationic dispersant. Typical examples of cationic functional groups include primary, secondary, or tertiary amino groups, pyridine groups, imidazole groups, benzimidazole groups, triazole groups, benzotriazole groups, pyrazole groups, and benzopyrazole groups. Examples of cationic dispersants include primary, secondary, tertiary, or quaternary amino group-containing acrylic polymers, polyethyleneimine, cationic polyvinyl alcohol resins, and cationic water-soluble hyperbranched polyesteramide resins. "(Meth)acrylic resin" refers to both acrylic resin and methacrylic resin.

[0025] Examples of commercially available cationic water-dispersible resins include "Superflex 620" and "Superflex 650" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "PP-15" and "PP-17" manufactured by Meisei Chemical Industry Co., Ltd., "Polysol AP-1350" manufactured by Showa Denko K.K., "Boncoat SFC-55" manufactured by DIC Corporation, and "Aquatex AC-3100" manufactured by Japan Coating Resins Co., Ltd. (all trade names).

[0026] The cationic polymers may be used alone or in combination of two or more. The cationic polymer preferably has an active ingredient content of 1 to 40% by mass, more preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and even more preferably 15 to 25% by mass.

[0027] Examples of organic acids include formic acid, acetic acid, lactic acid, oxalic acid, citric acid, malic acid, ascorbic acid, etc. Among these, organic acids that are liquid at 23°C are preferred, and examples of organic acids that are liquid at 23°C include acetic acid and lactic acid.

[0028] The organic acids may be used alone or in combination of two or more. The amount of the organic acid, in terms of active ingredient, is preferably 1 to 40 mass %, more preferably 5 to 40 mass %, more preferably 10 to 30 mass %, and even more preferably 15 to 25 mass %, relative to the total amount of the pretreatment liquid.

[0029] The pretreatment liquid preferably contains water.

[0030] The water is not particularly limited, but examples thereof include ion-exchanged water, distilled water, and ultrapure water. The water in the pretreatment liquid may be the balance of the flocculant and other optional components. For example, the water content is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, based on the total amount of the pretreatment liquid. The water content may be 95% by mass or less, 90% by mass or less, or 80% by mass or less, based on the total amount of the pretreatment liquid. The amount of water is, for example, preferably 20 to 95 mass %, more preferably 30 to 90 mass %, and even more preferably 40 to 80 mass %, based on the total amount of the pretreatment liquid.

[0031] The pretreatment liquid may contain a water-soluble organic solvent.

[0032] From the viewpoint of adjusting the viscosity of the pretreatment liquid and achieving moisturizing effect, the water-soluble organic solvent is preferably a liquid at room temperature and soluble in water.

[0033] The boiling point of the water-soluble organic solvent is preferably 180 to 300° C. To prevent clogging of the head when ejected by an inkjet method, the boiling point of the water-soluble organic solvent is preferably 180° C. or higher. Furthermore, to prevent solvent bleeding of images on printed textiles, the boiling point of the water-soluble organic solvent is preferably 300° C. or lower.

[0034] Examples of water-soluble organic solvents include lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, 1,3-propanediol, 1,3-butanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and 2-methyl-2-propanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol; glycerin; acetins such as monoacetin and diacetin; diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, and diethylene glycol dimethyl ether. Examples of suitable glycol derivatives include tetraethylene glycol monomethyl ether, diethylene glycol monoethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, triethylene glycol monohexyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether; triethanolamine, 2-pyrrolidone solvents such as 1-methyl-2-pyrrolidone, β-thiodiglycol, and sulfolane. Further examples include low molecular weight polyalkylene glycols such as polyethylene glycols having an average molecular weight in the range of 190 to 630, such as an average molecular weight of 200, 300, 400, or 600; diol-type polypropylene glycols having an average molecular weight in the range of 200 to 600, such as an average molecular weight of 400; and triol-type polypropylene glycols having an average molecular weight in the range of 250 to 800, such as an average molecular weight of 300 or 700.

[0035] The water-soluble organic solvents may be used alone or in combination of two or more. When two or more water-soluble organic solvents are used, it is preferable to use a combination that forms a single phase with water.

[0036] The content of the water-soluble organic solvent is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the pre-treatment liquid. The content of the water-soluble organic solvent is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on the total amount of the pre-treatment liquid. 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 or more, based on the total amount of the pre-treatment liquid.

[0037] The pretreatment liquid may further contain other components, such as a surfactant, an antifoaming agent, a pH adjuster, an antioxidant, and a preservative, as needed.

[0038] The surfactant may be any of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, but nonionic surfactants are preferred from the viewpoint of preventing foaming of the pretreatment liquid. In addition, either low-molecular-weight surfactants or high-molecular-weight surfactants may be used.

[0039] The HLB value of the surfactant is preferably 5-20, and more preferably 10-18.

[0040] 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 and silicone surfactants are preferably used.

[0041] 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).

[0042] 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). 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).

[0043] 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).

[0044] 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).

[0045] 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.

[0046] The amount of surfactant to be added varies depending on the type of surfactant, but from the viewpoints of the surface tension of the pretreatment liquid, the permeability of the pretreatment liquid into the fabric, etc., it is preferably 0.1 to 10 mass% of the active ingredient relative to the total amount of the pretreatment liquid, more preferably 0.2 to 5 mass%, and even more preferably 0.4 to 2 mass%. The amount of surfactant to be added is preferably 0.1 mass% or more of the active ingredient relative to the total amount of the pretreatment liquid, more preferably 0.2 mass% or more, and even more preferably 0.4 mass% or more. The amount of surfactant to be added is preferably 10 mass% or less of the active ingredient relative to the total amount of the pretreatment liquid, more preferably 5 mass% or less, and even more preferably 2 mass% or less.

[0047] The method for producing the pretreatment liquid is not particularly limited, and the pretreatment liquid can be produced by any known method. For example, the pretreatment liquid 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.

[0048] From the viewpoint of improving the hiding power, it is preferable that the specific gravity of the pretreatment liquid is higher than the specific gravity of the white ink. The specific gravity of the pretreatment liquid is preferably at least 0.001 higher than the specific gravity of the white ink, more preferably at least 0.005 higher, even more preferably at least 0.010 higher, even more preferably at least 0.020 higher, even more preferably at least 0.030 higher, and even more preferably at least 0.040 higher. The difference between the specific gravity of the pretreatment liquid and the specific gravity of the white ink may be, for example, 0.070 or less, 0.060 or less, or 0.050 or less. The difference between the specific gravity of the pretreatment liquid and the specific gravity of the white ink may be, for example, 0.001 to 0.070, 0.005 to 0.070, 0.010 to 0.070, 0.020 to 0.070, 0.030 to 0.060, or 0.040 to 0.050.

[0049] The specific gravity of the pretreatment liquid is a value at 23° C. and can be determined, for example, with a density specific gravity meter. For such measurements, for example, a portable density specific gravity meter "DA-130N" manufactured by Kyoto Electronics Manufacturing Co., Ltd. can be used.

[0050] The specific gravity of the pretreatment liquid is preferably 1.050 or more, more preferably 1.100 or more, and even more preferably 1.110 or more. The specific gravity of the pretreatment liquid is preferably 1.300 or less, and more preferably 1.200 or less. The specific gravity of the pretreatment liquid is preferably 1.050 to 1.300, more preferably 1.100 to 1.200, and even more preferably 1.110 to 1.200.

[0051] The specific gravity of the pretreatment liquid can be controlled by, for example, the type and amount of the components of the pretreatment liquid, such as the flocculant.

[0052] <White ink> The white ink can contain a white pigment as a coloring material.

[0053] 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.

[0054] 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.

[0055] The white pigment may be used alone or in combination of two or more kinds. From the viewpoint of hiding power, the amount of the white pigment is preferably 1% by mass or more, more preferably 3% by mass or more, and more preferably 5% by mass or more, of the total amount of ink in terms of active ingredients (pigment concentration). From the viewpoint of jetting performance, the amount of the white pigment is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, of the total amount of ink in terms of active ingredients (pigment concentration). The amount of the white pigment 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 ink in terms of active ingredients (pigment concentration).

[0056] In order to stably disperse the pigment in the ink, a pigment dispersant such as a polymer dispersant or a surfactant-type dispersant can be used. 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).

[0057] 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.

[0058] The white ink preferably contains water as an aqueous solvent, and the main solvent may be water. The water is not particularly limited, but it is preferable that the water contains as few ionic components as possible. In particular, from the viewpoint of storage stability of the ink, it is preferable that the content of polyvalent metal ions such as calcium is low. As the water, for example, ion-exchanged water, distilled water, ultrapure water, etc. may be used. From the viewpoint of adjusting the ink viscosity, the water content is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and even more preferably 30 to 60% by mass, of the total amount of white ink. The water content is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, of the total amount of white ink. The water content is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, of the total amount of white ink.

[0059] The white ink may contain a water-soluble organic solvent in addition to water. From the viewpoint of adjusting the viscosity of the ink and achieving a moisturizing effect, the water-soluble organic solvent is preferably a liquid at room temperature and soluble in water.

[0060] The boiling point of the water-soluble organic solvent is preferably 180 to 300° C. To prevent clogging of the head when ejected by an inkjet method, the boiling point of the water-soluble organic solvent is preferably 180° C. or higher. Furthermore, to prevent solvent bleeding of images on printed textiles, the boiling point of the water-soluble organic solvent is preferably 300° C. or lower.

[0061] As the water-soluble organic solvent, for example, one or a combination of two or more of the water-soluble organic solvents that can be blended in the pretreatment liquid described above can be used.

[0062] When two or more water-soluble organic solvents are used, it is preferable to use a combination that forms a single phase with water. From the viewpoints of adjusting the viscosity, moisturizing effect, and surface tension of the ink, the water-soluble organic solvent is preferably present in an amount of, for example, 1 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 10 to 30% by mass, relative to the total amount of ink. From the viewpoint of moisturizing effect, the water-soluble organic solvent is preferably present in an amount of 1% by mass, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the total amount of ink. From the viewpoint of adjusting the viscosity, the water-soluble organic solvent is preferably present in an amount of 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, relative to the total amount of ink.

[0063] The white ink preferably contains a surfactant.

[0064] By blending a surfactant as a surface tension adjuster into the white ink, the ink can be ejected more stably by inkjet printing and the ink's permeability into fabric can be more appropriately controlled. Furthermore, from the viewpoint of efficiently adjusting the surface tension of the white ink at 0.05 Hz and the surface tension of the ink at 10 Hz, it is preferable that the white ink contains a surfactant. The surfactant may be any of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, but nonionic surfactants are preferred from the viewpoint of preventing foaming of the ink. In addition, either low-molecular-weight surfactants or high-molecular-weight surfactants may be used.

[0065] The HLB value of the surfactant is preferably 5-20, and more preferably 10-18.

[0066] The surfactant may be, for example, one of the surfactants that can be blended in the pretreatment liquid, or a combination of two or more of them. From the viewpoint of efficiently adjusting the surface tension of the white ink at 0.05 Hz and the surface tension of the ink at 10 Hz, the surfactant is preferably an acetylene-based surfactant such as an acetylene glycol-based surfactant, and more preferably an acetylene glycol-based surfactant.

[0067] The amount of surfactant used as a pigment dispersant varies depending on the type of surfactant, but is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, even more preferably 0.2 to 4% by mass, and even more preferably 0.4 to 1% by mass, in terms of the active ingredient relative to the total amount of white ink, from the viewpoints of the surface tension of the white ink, the penetrability of the white ink into fabric, etc. The active ingredient amount of surfactant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.4% by mass. The active ingredient amount of surfactant is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 4% by mass or less, and even more preferably 1% by mass or less, in terms of the active ingredient relative to the total amount of white ink.

[0068] When the white ink contains a nonionic surfactant, the amount of the active ingredient of the nonionic surfactant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.4% by mass or more, based on the total amount of the white ink. The amount of the active ingredient of the nonionic surfactant is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on the total amount of the white ink. The amount of the active ingredient of the nonionic surfactant is preferably 0.1 to 5% by mass, more preferably 0.2 to 4% by mass, and even more preferably 0.4 to 1% by mass, based on the total amount of the white ink.

[0069] When the white ink contains an acetylene surfactant, the amount of the active ingredient of the acetylene surfactant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.4% by mass or more, based on the total amount of the white ink. The amount of the active ingredient of the acetylene surfactant is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on the total amount of the white ink. The amount of the active ingredient of the acetylene surfactant is preferably 0.1 to 5% by mass, more preferably 0.2 to 4% by mass or more, and even more preferably 0.4 to 1% by mass, based on the total amount of the white ink.

[0070] The white ink may further contain a water-dispersible resin, a water-soluble resin, or a combination thereof. From the viewpoint of sufficiently fixing the pigment to the substrate and thereby obtaining high coloring properties with a small amount of pigment, the white ink preferably contains at least one of a water-dispersible resin and a water-soluble resin. Examples of water-soluble resins include polyvinyl alcohol, polyacrylic acid, neutralized polyacrylic acid, acrylic acid / maleic acid copolymer, acrylic acid / sulfonic acid copolymer, styrene / maleic acid copolymer, etc. These may be used alone or in combination of two or more.

[0071] 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.

[0072] From the viewpoint of inkjet ejection properties, the average particle size 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 size of the water-dispersible resin may be in the range of 10 nm to 300 nm. Here, the average particle size of the resin is a volume-based average particle size, and is a value measured by a light scattering method.

[0073] The water-dispersible resin may be anionic, cationic, nonionic, or amphoteric. From the viewpoint of more stably dispersing the water-dispersible resin in the aqueous ink, the water-dispersible resin is preferably anionic or nonionic. The water-dispersible resin is preferably an anionic water-dispersible resin having an anionic functional group such as a carboxy group, a sulfo group, or a hydroxy group.

[0074] The type of water-dispersible resin used is preferably a resin that forms a transparent coating film. The water-dispersible resin can be blended as a resin emulsion when producing the ink. Representative examples include urethane resins, (meth)acrylic resins, styrene / (meth)acrylic resins, polyester resins, olefin resins, vinyl chloride resins, vinyl acetate resins, melamine resins, amide resins, ethylene-vinyl chloride copolymer resins, styrene-(meth)acrylic resins, styrene-maleic anhydride copolymer resins, vinyl acetate-(meth)acrylic copolymer resins, vinyl acetate-ethylene copolymer resins, silicone resins, and composite resins thereof.

[0075] The water-dispersible resin is preferably a water-dispersible urethane resin, a water-dispersible polyester resin, or a combination thereof.

[0076] Examples of commercially available water-dispersible resins include "Superflex 470" (water-dispersible urethane resin) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. and "Elitel KT9204" (water-dispersible polyester resin) manufactured by Unitika Ltd. (both are trade names).

[0077] The above-mentioned water-dispersible resins may be used alone or in combination of two or more.

[0078] The water-dispersible resin preferably has a nonvolatile content of 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the white ink. The water-dispersible resin preferably has a nonvolatile content of 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the white ink. For example, the water-dispersible resin preferably has a nonvolatile content of 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 20% by mass, based on the total amount of the white ink.

[0079] The mass ratio of the nonvolatile content of the water-dispersible resin to the pigment is preferably 0.1 to 10, more preferably 1 to 3, per 1 pigment.

[0080] The total amount of the water-dispersible resin and the water-soluble resin is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the white ink, in terms of nonvolatile content. The total amount of the water-dispersible resin and the water-soluble resin is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the white ink, in terms of nonvolatile content. For example, the total amount of the water-dispersible resin and the water-soluble resin is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 20% by mass, based on the total amount of the white ink, in terms of nonvolatile content.

[0081] The total amount of the water-dispersible resin and the water-soluble resin is preferably 0.1 to 10, more preferably 1 to 3, in terms of the mass ratio of the nonvolatile content to the pigment.

[0082] The white ink may contain other components as appropriate, such as a pH adjuster and a preservative.

[0083] 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.

[0084] The white ink can be used as a water-based inkjet ink for textile printing.

[0085] 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.

[0086] 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.

[0087] From the viewpoint of improving hiding power, the surface tension of the white ink at 0.05 Hz is preferably 33 mN / m or more, more preferably 35 mN / m or more, and even more preferably 35.5 mN / m or more. From the viewpoint of improving hiding power, the surface tension of the white ink at 0.05 Hz is preferably 39 mN / m or less, more preferably 38 mN / m or less, and even more preferably 37.5 mN / m or less. If the surface tension of the white ink at 0.05 Hz is 39 mN / m or less, the white ink tends to spread, increasing the area of the white ink covering the substrate and improving hiding power. From the viewpoint of improving hiding power, the surface tension of the white ink at 0.05 Hz is preferably 33 to 39 mN / m, more preferably 35 to 38 mN / m, and even more preferably 35.5 to 37.5 mN / m.

[0088] The surface tension of the white ink at 0.05 Hz can be controlled by, for example, the type and amount of surfactant, water-soluble organic solvent, and the like.

[0089] From the viewpoint of suppressing penetration of the white ink upon landing and thereby improving hiding power, the surface tension of the white ink at 10 Hz is preferably 40 mN / m or more, and more preferably 42 mN / m or more. The surface tension of the white ink at 10 Hz is preferably 60 mN / m or less, more preferably 55 mN / m or less, and even more preferably 50 mN / m or less. The surface tension of the white ink at 10 Hz is, for example, preferably 40 to 60 mN / m, more preferably 42 to 55 mN / m, and even more preferably 42 to 50 mN / m.

[0090] The surface tension of the white ink at 10 Hz can be controlled by, for example, the type and amount of surfactant, water-soluble organic solvent, and the like. From the viewpoint of efficiently controlling both values so that the surface tension of the white ink at 0.05 Hz is 39 mN / m or less and the surface tension of the white ink at 10 Hz is 40 mN / m or more, it is preferable that the white ink contains a surfactant.

[0091] The difference between the surface tension of the white ink at 10 Hz and the surface tension of the white ink at 0.05 Hz is preferably 1 mN / m or more, more preferably 2 mN / m or more, and even more preferably 5 mN / m or more. The difference between the surface tension of the white ink at 10 Hz and the surface tension of the white ink at 0.05 Hz is preferably 15 mN / m or more, more preferably 12 mN / m or less, and even more preferably 10 mN / m or less. The difference between the surface tension of the white ink at 10 Hz and the surface tension of the white ink at 0.05 Hz is, for example, preferably 1 to 15 mN / m, more preferably 2 to 12 mN / m, and even more preferably 5 to 10 mN / m.

[0092] The surface tension of the white ink at 0.05 Hz is the dynamic surface tension at a frequency of 0.05 Hz, and is the value at 23°C. It can be determined according to the bubble pressure method (maximum bubble pressure method) under measurement conditions of 23°C and 0.05 Hz. The surface tension of the white ink at 10 Hz is the dynamic surface tension at a frequency of 10 Hz, and is the value at 23°C. It can be determined according to the bubble pressure method (maximum bubble pressure method) under measurement conditions of 23°C and 10 Hz. These measurements can be performed using, for example, the SITA Messtechnik GmbH science line t60 manufactured by SITA Process Solutions.

[0093] The specific gravity of the white ink is preferably 1.050 or more, and more preferably 1.100 or more. The specific gravity of the white ink is preferably 1.300 or less, and more preferably 1.200 or less. The specific gravity of the white ink is preferably 1.050 to 1.300, and more preferably 1.100 to 1.200. The specific gravity of the white ink is a value at 23° C., and can be determined in the same manner as for the pretreatment liquid.

[0094] The specific gravity of the white ink can be controlled by, for example, the type and amount of pigment.

[0095] <Color ink> Examples of color inks include magenta ink, cyan ink, yellow ink, black ink, and other inks other than white ink.

[0096] The color ink may contain, as a colorant, a pigment, a dye, or a combination thereof, and preferably contains a pigment.

[0097] The pigment preferably includes a non-white pigment.

[0098] Examples of non-white pigments include organic pigments such as azo pigments, phthalocyanine pigments, dye pigments, condensed polycyclic pigments, nitro pigments, and nitroso pigments (such as Brilliant Carmine 6B, Lake Red C, Watching Red, Disazo Yellow, Hansa Yellow, Phthalocyanine Blue, Phthalocyanine Green, Alkali Blue, and Aniline Black); metals such as cobalt, iron, chromium, copper, zinc, lead, titanium, vanadium, manganese, and nickel, metal oxides and sulfides, and inorganic pigments such as ochre, ultramarine, and iron blue; and carbon blacks such as furnace carbon black, lamp black, acetylene black, and channel black.

[0099] The average particle size of the pigment is preferably 50 nm or more from the viewpoint of color development, and preferably 500 nm or less from the viewpoint of ejection stability. For example, the average particle size of the pigment is preferably 50 to 500 nm, and more preferably 50 to 200 nm.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] A dye may be blended as a coloring material. Any dye commonly used in the printing technical field can be used as the dye, and is not particularly limited. Specific examples include basic dyes, acid dyes, direct dyes, soluble vat dyes, acid mordant dyes, mordant dyes, reactive dyes, vat dyes, and sulfide dyes. Among these, water-soluble dyes and those that become water-soluble upon reduction or the like are preferably used. More specific examples include azo dyes, rhodamine dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, triphenylmethane dyes, diphenylmethane dyes, and methylene blue.

[0105] The coloring materials may be used alone or in combination of two or more. The amount of colorant blended varies depending on the type of colorant, but from the viewpoints of shielding properties, color development, etc., it is preferably 0.1% by mass or more, more preferably 1% by mass or more, and more preferably 3% by mass or more, of the active ingredient (colorant concentration, for example, pigment, etc.) relative to the total amount of color ink. The amount of colorant blended is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 15% by mass or less, and even more preferably 10% by mass or less, of the active ingredient (colorant concentration) relative to the total amount of color ink. The amount of colorant blended is preferably 0.1 to 30% by mass, more preferably 1 to 25% by mass, even more preferably 3 to 15% by mass, and even more preferably 3 to 10% by mass, of the active ingredient (colorant concentration) relative to the total amount of ink.

[0106] When a pigment is blended as a coloring material in a color ink, a pigment dispersant, such as a polymer dispersant or a surfactant-type dispersant, can be used to stably disperse the pigment in the color ink.

[0107] As the pigment dispersant, for example, one type or a combination of two or more types selected from the pigment dispersants that can be blended in the white ink described above can be used. 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.

[0108] The color ink preferably contains water as an aqueous solvent, and the main solvent may be water. The water is not particularly limited, but it is preferable that the water contains as few ionic components as possible. In particular, from the viewpoint of storage stability of the ink, it is preferable that the content of polyvalent metal ions such as calcium is low. As the water, for example, ion-exchanged water, distilled water, ultrapure water, etc. may be used. 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.

[0109] The color ink may contain a water-soluble organic solvent in addition to or in place of water. From the viewpoint of adjusting the viscosity of the ink and achieving a moisturizing effect, the water-soluble organic solvent is preferably a liquid at room temperature and soluble in water. As the water-soluble organic solvent, for example, one or a combination of two or more of the water-soluble organic solvents that can be blended in the pretreatment liquid described above can be used.

[0110] When two or more water-soluble organic solvents are used, it is preferable to use a combination that forms a single phase with water. From the viewpoints of adjusting the viscosity of the ink and achieving a moisturizing effect, the water-soluble organic solvent is preferably contained in an amount of 1 to 50% by mass, and more preferably 10 to 40% by mass, relative to the total amount of the ink. The water-soluble organic solvent is preferably contained in an amount of 1% by mass, and more preferably 10% by mass or more, relative to the total amount of the ink. The water-soluble organic solvent is preferably contained in an amount of 50% by mass or less, and more preferably 40% by mass or less, relative to the total amount of the ink.

[0111] The color ink preferably contains a surfactant.

[0112] The surfactant may be any of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, but nonionic surfactants are preferred from the viewpoint of preventing foaming of the ink. In addition, either low-molecular-weight surfactants or high-molecular-weight surfactants may be used.

[0113] The HLB value of the surfactant is preferably 5-20, and more preferably 10-18. As the surfactant, for example, one or a combination of two or more surfactants selected from the surfactants that can be blended in the pretreatment liquid described above can be used.

[0114] The amount of surfactant to be blended is the total amount when a surfactant is used as a pigment dispersant, and varies depending on the type of surfactant, but from the viewpoints of the surface tension of the color ink, the permeability of the color ink into fabric, etc., the amount of active ingredient is preferably 0.1 to 10 mass%, and more preferably 0.2 to 5 mass%, relative to the total amount of the color ink.

[0115] The color ink may further contain a water-dispersible resin, a water-soluble resin, or a combination thereof. From the viewpoint of sufficiently fixing the colorant to the substrate and thereby obtaining high coloring properties with a small amount of colorant, the color ink preferably contains at least one of a water-dispersible resin and a water-soluble resin. As the water-soluble resin, for example, one type or a combination of two or more types selected from the water-soluble resins that can be blended into the white ink described above can be used.

[0116] 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.

[0117] From the viewpoint of inkjet ejection properties, the average particle size 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 size of the water-dispersible resin may be in the range of 10 nm to 300 nm. Here, the average particle size of the resin is a volume-based average particle size, and is a value measured by a light scattering method.

[0118] The water-dispersible resin may be anionic, cationic, nonionic, or amphoteric. From the viewpoint of more stably dispersing the water-dispersible resin in the aqueous ink, the water-dispersible resin is preferably anionic or nonionic. The water-dispersible resin is preferably an anionic water-dispersible resin having an anionic functional group such as a carboxy group, a sulfo group, or a hydroxy group.

[0119] The type of water-dispersible resin used is preferably a resin that forms a transparent coating film. The water-dispersible resin can be blended as a resin emulsion when producing the ink. As the water-dispersible resin, for example, one or a combination of two or more of the above-mentioned water-dispersible resins that can be blended into the white ink can be used. As the water-dispersible resin, a water-dispersible urethane resin is preferred.

[0120] The above-mentioned water-dispersible resins may be used alone or in combination of two or more.

[0121] The amount of the water-dispersible resin in terms of nonvolatile content 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 amount of the water-dispersible resin in terms of nonvolatile content is preferably 30% by mass or less, and more preferably 20% by mass or less, based on the total amount of the color ink. For example, the amount of the water-dispersible resin in terms of nonvolatile content 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 color ink.

[0122] The mass ratio of the nonvolatile content of the water-dispersible resin to the colorant is preferably 0.1 to 10, more preferably 1 to 3, per 1 of the colorant.

[0123] The total amount of the water-dispersible resin and the water-soluble resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, in terms of nonvolatile content, relative to the total amount of the color ink. The total amount of the water-dispersible resin and the water-soluble resin is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, in terms of nonvolatile content, relative to the total amount of the color ink. For example, the total amount of the water-dispersible resin and the water-soluble resin is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass in terms of nonvolatile content, relative to the total amount of the color ink.

[0124] The total amount of the water-dispersible resin and the water-soluble resin is preferably 0.1 to 10, more preferably 1 to 3, in terms of the mass ratio of the nonvolatile content to the colorant.

[0125] The color ink may contain other components as appropriate, such as a pH adjuster and a preservative.

[0126] 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.

[0127] The color inks can be used as aqueous textile printing inks, and more preferably, the color inks can be used as aqueous textile inkjet inks.

[0128] 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.

[0129] 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.

[0130] <Method for manufacturing printed items> A method for producing a printed textile according to one embodiment includes applying the pretreatment liquid to the fabric, and applying the white ink to the fabric by an inkjet method after the application of the pretreatment liquid. The application of the white ink can be performed by a wet-on-wet method within 100 seconds after the application of the pretreatment liquid.

[0131] The area to which the pretreatment liquid is applied may be an area corresponding to an area where an image is formed with white ink, or may be a partial or entire area of the fabric. The pretreatment liquid is preferably applied to at least a part of the area where an image is formed with white ink. The method for applying the pretreatment liquid to the fabric is not particularly limited, and any method can be used, such as a spraying method using an airbrush or the like, a dipping method, a padding method, or a coating method. Furthermore, various printing methods such as inkjet printing (inkjet method) and screen printing may also be used. As an inkjet printer for applying the pretreatment liquid by the inkjet method, for example, an inkjet printer that can be used as an inkjet printer for applying ink to fabric, which will be described later, can be used. In the case of the inkjet method, it is preferable that, for example, droplets of the pretreatment liquid are ejected from an inkjet head based on a digital signal and the ejected ink droplets are deposited on the fabric.

[0132] The amount of pretreatment liquid applied to the fabric is 10 to 300 g / m 2 is preferable, and 20 to 200 g / m 2 is preferable, and 30 to 150 g / m 2 From the viewpoint of hiding power, the amount of the pretreatment liquid to be applied is more preferably 10 g / m 2 More than 20g / m is preferable. 2 More preferably, 30 g / m 2 On the other hand, from the viewpoint of image quality, the amount of the pretreatment liquid to be applied is 300 g / m 2 Preferably less than 200 g / m 2 Less than 150 g / m is more preferable. 2 The following is even more preferred: The amount of pretreatment liquid applied to the fabric is 1 to 100 g / m as the amount of the active ingredient of the flocculant. 2 is preferred, and 5 to 80 g / m 2 is preferable, and 10 to 50 g / m 2 is more preferred.

[0133] The white ink can be applied to the fabric by an inkjet method. The inkjet printer used when applying the white ink to the fabric by the inkjet method may be of any type, such as a piezoelectric type, an electrostatic type, a thermal type, etc. For example, it is preferable to eject ink droplets from an inkjet head based on a digital signal and allow the ejected ink droplets to adhere to the fabric.

[0134] The amount of white ink applied to the fabric is not particularly limited, but is preferably 500 g / m per unit area of fabric. 2 Preferably, it is 400 g / m or less. 2 More preferably, it is 300 g / m or less. 2 It is more preferable that the amount of white ink applied to the fabric is 10 g / m or less. 2 More than 50g / m 2 More preferably, 100 g / m 2 The amount of white ink applied to the fabric is, for example, 10 to 500 g / m 2 is preferable, and 50 to 400 g / m 2 More preferably, 100 to 300 g / m 2 is more preferable.

[0135] The white ink is preferably applied to the fabric by a wet-on-wet method after the application of the pretreatment liquid. Specifically, the white ink is preferably applied to the fabric after the application of the pretreatment liquid without performing a drying process such as heat drying. After the application of the pretreatment liquid, the temperature of the fabric surface before the application of the white ink is preferably 40°C or less, more preferably 35°C or less. After the application of the pretreatment liquid, the white ink is preferably applied in a state where the amount of volatile components of the pretreatment liquid remaining on the fabric is 90% by mass or more.

[0136] The application of the white ink is preferably performed within 100 seconds after the application of the pretreatment liquid and by a wet-on-wet method. "Within 100 seconds after the application of the pretreatment liquid" means that the time between the time when the pretreatment liquid is applied to a certain point on the substrate (fabric) in the application area and the time when droplets of the white ink land at that point (hereinafter, also referred to as "the time from the application of the pretreatment liquid to the application of the white ink") is within 100 seconds. When the pretreatment liquid and the white ink are each printed by an inkjet method in multiple passes, the "time from the application of the pretreatment liquid to the application of the white ink" means the time between the time when the first droplet of the pretreatment liquid lands at a certain point on the substrate (fabric) in the application area and the time when the first droplet of the white ink lands at that point.

[0137] For example, when the pretreatment liquid is applied by an inkjet method, the time from the application of the pretreatment liquid to the application of the white ink can be adjusted by the distance between the nozzles of the inkjet head that ejects the pretreatment liquid and the nozzles of the inkjet head that ejects the white ink, the scanning speed and scanning distance of the inkjet head, the ejection speed and ejection timing of the inkjet head, etc.

[0138] From the viewpoint of improving hiding power, the time from application of the pretreatment liquid to application of the white ink is preferably 100 seconds or less, more preferably 95 seconds or less, and even more preferably 50 seconds or less, and may be 20 seconds or less or 10 seconds or less. The time from the application of the pretreatment liquid to the application of the white ink is, for example, preferably 1 second or more, more preferably 3 seconds or more, and even more preferably 5 seconds or more. The time from application of the pretreatment liquid to application of the white ink may be, for example, 1 to 100 seconds, 1 to 95 seconds, 1 to 50 seconds, 3 to 50 seconds, 3 to 20 seconds, 5 to 20 seconds, or 3 to 10 seconds.

[0139] When the surface tension of the white ink at 0.05 Hz is 33 to 39 mN / m, the shorter the time between the application of the pretreatment liquid and the application of the white ink, the more pretreatment liquid can react with the white ink per unit area, and the more the hiding power tends to improve. For example, the surface tension of the white ink at 0.05 Hz may be 33 to 39 mN / m, more preferably 35 to 38 mN / m, and the time from application of the pretreatment liquid to application of the white ink may be 1 to 50 seconds.

[0140] If the surface tension of the white ink at 0.05 Hz is low, the white ink applied to the fabric tends to easily bleed, and therefore, if the time between the application of the pretreatment liquid and the application of the white ink is short, the white ink may spread beyond the area where the pretreatment liquid has adhered before the pretreatment liquid bleeds, resulting in a decrease in hiding power. For example, if the surface tension of the white ink at 0.05 Hz is less than 35 mN / m, from the perspective of further improving hiding power, the time between the application of the pretreatment liquid and the application of the white ink is preferably 5 seconds or more, more preferably 10 seconds or more, and even more preferably 20 seconds or more.

[0141] When the surface tension of the white ink at 0.05 Hz increases, the white ink becomes less likely to penetrate or bleed, and the amount of pretreatment liquid required tends to decrease. As a result, the effects of penetration and bleed of the pretreatment liquid over time are also reduced, and the effect of the time between application of the treatment liquid and application of the white ink on hiding power is also reduced.

[0142] It is preferable to provide a step of heating the fabric after applying the white ink to the fabric. The temperature at which the fabric to which the white ink has been applied is heated can be appropriately selected depending on the material of the fabric, etc. The temperature at which the fabric to which the white ink has been applied is, for example, preferably 100°C or higher, and more preferably 150°C or higher. From the viewpoint of reducing damage to the fabric, the temperature at which the fabric to which the white ink has been applied is preferably 200°C or lower. The device for heating the fabric to which the white ink has been applied is not particularly limited, and examples that can be used include a heat press, a roll heater, a hot air device, an infrared lamp heater, etc. These heating devices may be provided integrally with the inkjet printer. The time for heating the fabric to which the white ink has been applied may be set appropriately depending on the heating method, etc. For example, in the case of a heat press, the time is preferably 1 second to 10 minutes, and may be 5 seconds to 5 minutes.

[0143] The method for producing a printed item preferably further includes applying the above-described color ink after applying the white ink. The method for producing a printed item according to one embodiment has excellent hiding power for a substrate, and therefore, by applying a color ink after applying a white ink, a printed item on which an image with excellent color development is formed can be produced.

[0144] The method for applying the color ink to the fabric is not particularly limited, and any method can be used, such as a spray method using an airbrush or the like, a dipping method, a pad method, or a coating method. Furthermore, various printing methods such as inkjet printing (inkjet method) and screen printing may also be used, but inkjet printing is preferred. As an inkjet printer for applying color inks by the inkjet method, for example, an inkjet printer that can be used as an inkjet printer for applying the above-mentioned white ink to fabric can be used. In the case of the inkjet method, it is preferable to eject ink droplets from an inkjet head based on a digital signal, and to allow the ejected ink droplets to adhere to the fabric.

[0145] The amount of color ink applied to the fabric is not particularly limited, but is preferably 100 g / m per unit area of fabric. 2 Preferably, it is 50 g / m or less. 2 More preferably, it is 30 g / m or less. 2 It is even more preferable that: The amount of color ink applied to the fabric is not particularly limited, but from the viewpoint of image density, 1 g / m 2 More than 3g / m is preferable. 2 More preferably, 5 g / m 2 The amount of color ink applied to the fabric is, for example, 1 to 100 g / m 2 is preferred, and 3 to 50 g / m2 More preferably, 4 to 30 g / m 2 is more preferable.

[0146] The color ink is preferably applied to the fabric by a wet-on-wet method after the application of the white ink. Specifically, it is preferable to apply the color ink to the fabric after the application of the white ink without performing a drying process such as heat drying. After the application of the white ink, it is preferable that the temperature of the fabric surface be 40°C or less, more preferably 35°C or less, until the application of the color ink begins. After the application of the white ink, it is preferable that the color ink be applied when the amount of volatile matter remaining on the fabric from the white ink is 90% by mass or more.

[0147] It is preferable to provide a step of heating the fabric after applying the color ink to the fabric. The temperature at which the fabric to which the color ink has been applied is heated can be appropriately selected depending on the material of the fabric, etc. The temperature at which the fabric to which the color ink has been applied is, for example, preferably 100°C or higher, more preferably 150°C or higher. From the viewpoint of reducing damage to the fabric, this heating temperature is preferably 200°C or lower. The temperature at which the fabric to which the color ink has been applied is heated may be set appropriately depending on the heating method, etc. For example, in the case of heat pressing, the temperature is preferably 1 second to 10 minutes, and may be 5 seconds to 5 minutes. The device for heating the cloth to which the color ink has been applied is not particularly limited, and a device similar to the device for heating the cloth to which the white ink has been applied described above can be used.

[0148] 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.

[0149] <Ink set> According to one embodiment, there is provided an ink set for inkjet textile printing, which includes a pretreatment liquid containing a flocculant, water, and a surfactant, and a white ink containing a white pigment and water. As the pretreatment liquid and the white ink, the pretreatment liquid and the white ink that can be used in the above-described method for producing a printed item can be used. The inkjet textile printing ink set may further include color inks. As the color inks, color inks that can be used in the above-mentioned method for producing a textile print can be used. The inkjet textile printing ink set may further include a post-treatment liquid and the like. [Example]

[0150] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples. In the following description, "%" means "% by mass" unless otherwise specified.

[0151] <Production of pretreatment liquid> Table 1 shows the raw materials and physical properties (specific gravity) of pretreatment solutions UC1 to UC4. The blending ratios of the raw materials in the table include the amounts of solvents, etc., if any, contained in the materials. The raw materials were mixed in the blending ratios shown in Table 1 to obtain the pretreatment solutions. The specific gravity of each pretreatment liquid shown in Table 1 was measured at 23°C using a portable density / specific gravity meter "DA-130N" manufactured by Kyoto Electronics Manufacturing Co., Ltd.

[0152] [Table 1]

[0153] Details of the materials listed in Table 1 are given below. (flocculant) Calcium nitrate tetrahydrate: Fujifilm Wako Pure Chemical Industries, Ltd., active ingredient (as anhydrous hydrate) 69% by mass Calcium chloride: Fujifilm Wako Pure Chemical Industries, Ltd., active ingredient 100% by mass (Water-soluble organic solvent) 1,3-Propanediol: Fujifilm Wako Pure Chemical Industries, Ltd. Diethylene glycol: Fujifilm Wako Pure Chemical Industries, Ltd. (surfactant) Surfynol 485: Acetylenic surfactant, manufactured by Evonik Industries, active ingredient 100% by mass Olfine E1030W: Acetylenic surfactant, manufactured by Nissin Chemical Industry Co., Ltd., active ingredient 75% by mass

[0154] <White ink production> The raw materials and physical properties (surface tension and specific gravity) of the white inks W1 to W6 are shown in Table 2. The blending ratios of the raw materials in the table include the amounts of solvents, etc., if any, contained in the materials. The materials were mixed according to the blending ratios shown in Table 2 and filtered through a membrane filter with a pore size of 3 μm to obtain a white ink.

[0155] The surface tension of each white ink shown in Table 2 at 0.05 Hz was measured using a SITA Messtechnik GmbH science line t60 manufactured by SITA Process Solutions at 23°C and 0.05 Hz. The surface tension of the white ink at 10 Hz was measured using a SITA Messtechnik GmbH science line t60 manufactured by SITA Process Solutions at 23°C and 10 Hz. The specific gravity of each white ink shown in Table 2 was measured at 23°C using a portable density / specific gravity meter "DA-130N" manufactured by Kyoto Electronics Manufacturing Co., Ltd.

[0156] [Table 2]

[0157] Details of the materials listed in Table 2 are given below.

[0158] (Pigment dispersion) White pigment dispersion: Obtained by the following method, pigment content 35% by mass (Water dispersible resin) Superflex 470: Water-dispersible urethane resin (water-based resin emulsion), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., active ingredient 38% by mass Elitel KT9204: Water-dispersible polyester resin (water-based resin emulsion), manufactured by Unitika Ltd., active ingredient 30% by mass

[0159] (Water-soluble organic solvent) Glycerin: Fujifilm Wako Pure Chemical Industries, Ltd. 1,3-Propanediol: Fujifilm Wako Pure Chemical Industries, Ltd. Diethylene glycol: Fujifilm Wako Pure Chemical Industries, Ltd. Diethylene glycol monobutyl ether: Fujifilm Wako Pure Chemical Industries, Ltd. (surfactant) Surfynol 465: Acetylenic surfactant, manufactured by Evonik Industries, active ingredient 100% by mass Olfine E1010: Acetylenic surfactant, manufactured by Nissin Chemical Industry Co., Ltd., active ingredient 100% by mass

[0160] <Production of White Pigment Dispersion> 350 g of titanium dioxide "TIPAQUE R-980" (manufactured by Ishihara Sangyo Kaisha) was used as the white pigment, and 17.5 g (3.5 g of active ingredient) of "Demol P" (manufactured by Kao Corporation) was used as the pigment dispersant. These were mixed with 632.5 g of ion-exchanged water, and dispersed with 0.5 mm diameter zirconia beads using a bead mill (manufactured by Shinmaru Enterprises, DYNO-MILL KDL A type) at a filling rate of 80% and a residence time of 2 minutes, yielding a pigment dispersion (pigment content 35% by mass). This was designated as the white pigment dispersion.

[0161] <Color ink manufacturing> The raw materials of color ink C1 are shown in Table 3. The blending ratio of the raw materials in the table includes the amount of solvents, etc., if any, contained in the material. Each material was mixed according to the blending ratio shown in Table 3, and filtered through a membrane filter with a pore size of 3 μm to obtain a color ink.

[0162] [Table 3]

[0163] Details of the materials listed in Table 3 are given below.

[0164] (Pigment dispersion) CAB-O-JET450C: Self-dispersing pigment dispersion (cyan), manufactured by Cabot Japan Co., Ltd., pigment content 15% by weight (Water dispersible resin) Superflex 470: Water-dispersible urethane resin (water-based resin emulsion), manufactured by Daiichi Kogyo Seiyaku Co., Ltd., active ingredient 38% by mass (Water-soluble organic solvent) Glycerin: Fujifilm Wako Pure Chemical Industries, Ltd. Diethylene glycol: Fujifilm Wako Pure Chemical Industries, Ltd. (surfactant) Olfine E1010: Acetylenic surfactant, manufactured by Nissin Chemical Industry Co., Ltd., active ingredient 100% by mass

[0165] <Production of white printed items> Tables 4 and 5 show the pretreatment liquids and white inks used in producing the white printed items of Examples 1 to 8 and Comparative Examples 1 to 7. White printed materials of Examples 1 to 8 and Comparative Examples 1 to 7 were produced as follows. A black cotton T-shirt (product name: Printstar) manufactured by TMS Co., Ltd. was used as the substrate. A pretreatment liquid and a white ink were applied to this substrate in this order using a wet-on-wet method using an inkjet printer MMP-8130 manufactured by Mastermind, to form a solid white ink image. The amounts of the pretreatment liquid applied were 50 g / m for Pretreatment Liquid UC1 and 125 g / m for Pretreatment Liquid UC2. 2 , pretreatment liquid UC3 at 100g / m 2 , pretreatment liquid UC4 84g / m2 The amount of white ink applied was 200 g / m in all of Examples 1 to 8 and Comparative Examples 1 to 7. 2 It was decided. Thereafter, the resultant was dried by heating at 160° C. for 2 minutes using a Hotronix Fusion heat press to obtain a white printed product.

[0166] In Tables 4 and 5, the "time from application of the pretreatment liquid to application of the white ink" for Examples 1 to 8 and Comparative Examples 1 to 7 was adjusted by changing the scanning distance of the inkjet head (scanning distance in the main scanning direction) by changing the image size.

[0167] <Production of color printed items> In the production of the white printed products of Examples 1 to 4 and Comparative Examples 1 to 7, after the application of the white ink, the color ink C1 (cyan ink) produced above was applied in an amount of 12 g / m using a wet-on-wet method with an inkjet printer MMP-8130 manufactured by Mastermind, without drying using a heat press. 2 Printed in. Thereafter, the fabric was dried by heating at 160°C for 2 minutes using a Hotronix Fusion heat press to obtain a color-printed fabric.

[0168] <Evaluation> (Concealment) The white printed materials of Examples 1 to 8 and Comparative Examples 1 to 7 were visually observed and evaluated according to the following evaluation criteria. The results are shown in Tables 4 and 5. S: No areas where the base color shows through A: There are areas where the color of the base material shows through. B: The color of the base material is clearly visible in some areas

[0169] (Color development) The color printed materials of Examples 1 to 4 and Comparative Examples 1 to 7 were visually observed and evaluated according to the following evaluation criteria. The results are shown in Tables 6 and 7. S: The color of the substrate is not noticeable and the color of the color ink is good. A: The color of the base material is slightly visible, but the color of the color ink is good. B: The color of the base material is noticeable, and the color ink does not show up well.

[0170] [Table 4]

[0171] [Table 5]

[0172] [Table 6]

[0173] [Table 7]

[0174] As shown in each table, the white printed material of each example was excellent in hiding power, and the color printed material of each example exhibited excellent color development. Furthermore, in Examples 1 to 4, which used white ink W1 with a surface tension of 36.7 mN / m at 0.05 Hz, the hiding power increased as the time between application of the pretreatment liquid and application of the white ink became shorter.

[0175] On the other hand, in Comparative Example 1, in which the time from application of the pretreatment liquid to application of the white ink was 120 seconds, the hiding power of the white printed material was low, and the color development of the color printed material was also poor. Comparative Examples 2, 3, and 4, which used white inks with high surface tension at 0.05 Hz, also had poor hiding power on white-printed items and poor evaluations of color development on color-printed items. Furthermore, in the evaluation of the hiding power of white-printed items, no difference in hiding power was observed depending on the time between application of the pretreatment liquid and application of the white ink. In Comparative Example 5, which used a white ink with a low surface tension at 0.05 Hz, Comparative Example 6, in which the specific gravity of the pretreatment liquid was lower than that of the white ink, and Comparative Example 7, in which the surface tension of the white ink at 10 Hz was low, the hiding power of white-printed items was low and the color development of color-printed items was poor.

Claims

1. applying a pretreatment liquid containing a flocculant, water, and a surfactant to the fabric; applying a white ink containing a white pigment and water to the fabric by an inkjet method after applying the pretreatment liquid; the surface tension of the white ink at 0.05 Hz is 33 to 39 mN / m; the surface tension of the white ink at 10 Hz is 40 mN / m or more; the specific gravity of the pretreatment liquid is higher than the specific gravity of the white ink, the white ink is applied within 100 seconds after the pretreatment liquid is applied, and is applied by a wet-on-wet method; Method for manufacturing printed materials.

2. the surface tension of the white ink at 0.05 Hz is 35 to 38 mN / m; 2. The method for producing a printed item according to claim 1, wherein the white ink is applied 1 to 50 seconds after the pretreatment liquid is applied.

3. The method for producing a printed item according to claim 1 or 2, further comprising applying a color ink by a wet-on-wet method after applying the white ink.

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