Inkjet printing method, ink composition, and inkjet printing device

Abstract

To provide an inkjet printing method exhibiting excellent texture and reduced stickiness.SOLUTION: This inkjet printing method comprises the steps for discharging onto a fabric an ink composition containing an anionic resin and a silicone-acrylic resin having a film elongation of 600% to 1600% to form a wet image, and irradiating the formed wet image with infrared rays to form a dried image.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an inkjet textile printing method, an ink composition, and an inkjet textile printing apparatus. [Background technology]

[0002] Conventionally, exhaustion printing, in which fabric is immersed in a bath filled with dye, has been known as a printing method, but this requires a long time for dyeing, resulting in low production efficiency. In recent years, inkjet printing, in which an image is formed on a fabric cab using an inkjet method, has become widespread because it allows dyeing in a short time and has high production efficiency. In inkjet printing, tiny ink droplets are ejected from an inkjet recording head and land on the fabric to form an image (see, for example, Patent Document 1).

[0003] Patent Document 1 describes a method of printing on fabric by an inkjet recording method using an inkjet textile printing ink. The inkjet textile printing ink described in Patent Document 1 contains a water-dispersible resin, a pigment, a water-soluble organic solvent, and water. The water-dispersible resin is a urethane resin with a film elongation in the range of 600% to 2000%. The weight ratio of the pigment to the water-dispersible resin is 1:3 to 1:16. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-7543 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the image forming method using the inkjet textile printing ink described in Patent Document 1 improves the texture, feel, appearance, etc. of the formed image, there is room for improvement in terms of stickiness of the image.

[0006] An object of the present invention is to provide an ink-jet textile printing method, an ink composition, and an ink-jet textile printing apparatus that are good in texture and stickiness. [Means for solving the problem]

[0007] An inkjet textile printing method according to one embodiment of the present invention includes a step of ejecting an ink composition containing an anionic resin and a silicone acrylic resin, each having a film elongation of 600 to 1600%, onto a fabric to form a wet image, and a step of irradiating the wet image with infrared rays to form a dry image.

[0008] The ink composition according to one embodiment of the present invention contains an anionic resin having a film elongation of 600 to 1600% and a silicone acrylic resin.

[0009] An inkjet textile printing apparatus according to one embodiment of the present invention includes an image forming unit that ejects the ink composition of the present invention onto a fabric to form an image in a wet state, and a drying unit that dries the image in the wet state by infrared drying to form an image in a dry state. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an inkjet textile printing method, an ink composition, and an inkjet textile printing apparatus that are excellent in texture and stickiness. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an inkjet textile printing device. [Figure 2] FIG. 2 is a flowchart of the inkjet printing method. DETAILED DESCRIPTION OF THE INVENTION

[0012] An inkjet textile printing method, an ink composition, and an inkjet textile printing apparatus according to one embodiment of the present invention will be described below. The present invention is not limited to the following embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the following explanation, the ink composition used in the inkjet textile printing method will be described first, followed by an explanation of the inkjet textile printing apparatus and the inkjet textile printing method.

[0013] [Configuration of ink composition] The ink composition of this embodiment contains an anionic resin and a silicone acrylic resin. The treatment liquid that is ejected onto the fabric before the ink composition is ejected onto the fabric is also referred to as a "pretreatment liquid (first treatment liquid)." The ink composition may also contain an ink for forming an image and a post-treatment liquid (second treatment liquid, overcoat liquid) for covering the image. In this case, the silicone acrylic resin is contained in the ink or the post-treatment liquid. That is, when the ink composition contains an ink and a post-treatment liquid, the silicone acrylic resin may be contained only in the ink, only in the post-treatment liquid, or in both the ink and the post-treatment liquid. In this embodiment, a case will be described in which the ink composition contains an ink and a post-treatment liquid, and the silicone acrylic resin is contained in both the ink and the post-treatment liquid.

[0014] The ink contains an anionic resin and a silicone acrylic resin. In addition to the above components, the ink may also contain a pigment, a water-soluble organic solvent, and water. In this embodiment, the ink contains a pigment, an anionic resin, a silicone acrylic resin, a water-soluble organic solvent, and water.

[0015] The pigment may be an organic pigment or an inorganic pigment such as titanium oxide. Generally, the pigment is anionic. One type of pigment may be used alone, or multiple types may be used in combination.

[0016] Examples of organic pigments include azo, azomethine, methine, diphenylmethane, triphenylmethane, quinacridone, anthraquinone, and perylene, and other examples of organic pigments include indigo, quinophthalone, isoindolinone, isoindoline, azine, oxazine, thiazine, dioxazine, thiazole, phthalocyanine, and diketopyrrolopyrrole.

[0017] Examples of organic pigments for magenta or red include CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, and CI Pigment Red 15. Other examples of organic pigments for magenta or red include CI Pigment Red 16, CI Pigment Red 48:1, CI Pigment Red 53:1, CI Pigment Red 57:1, and CI Pigment Red 122. Other examples of organic pigments for magenta or red include CI Pigment Red 123, CI Pigment Red 139, CI Pigment Red 144, CI Pigment Red 149, and CI Pigment Red 166. Other examples of organic pigments for magenta or red include CI Pigment Red 177, CI Pigment Red 178, CI Pigment Red 202, CI Pigment Red 222, and CI Pigment Violet 19. Some pigments may be mixed crystals.

[0018] Examples of organic pigments for orange include CI Pigment Orange 31 and CI Pigment Orange 43. Examples of organic pigments for yellow include CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 15:3, and CI Pigment Yellow 17. Examples of organic pigments for yellow include CI Pigment Yellow 74, CI Pigment Yellow 93, CI Pigment Yellow 128, CI Pigment Yellow 94, CI Pigment Yellow 138, and CI Pigment Yellow 155.

[0019] Examples of organic pigments for green or cyan include CI Pigment Blue 15, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 16, CI Pigment Blue 60, and CI Pigment Green 7.

[0020] Examples of organic pigments for black include CI Pigment Black 1, CI Pigment Black 6, and CI Pigment Black 7.

[0021] The titanium oxide is preferably rutile titanium oxide, which has a high refractive index and high hiding power. Commercially available examples of titanium oxide include the TR series (Fuji Titanium Industry Co., Ltd.), the JR series (Teika Corporation), and Typec (Ishihara Sangyo Kaisha, Ltd.).

[0022] The pigment may be a self-dispersing pigment. A self-dispersing pigment is a pigment particle whose surface is modified with a hydrophilic group, and has pigment particles and hydrophilic groups bonded to the surface.

[0023] Examples of the hydrophilic group include a carboxy group, a sulfonic acid group, and a phosphorus-containing group. Examples of the phosphorus-containing group include a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a phosphite group, and a phosphate group.

[0024] Commercially available examples of self-dispersing pigments include Cab-0-Jet® 200K, 250C, 260M, and 270V, which are sulfonic acid group-containing self-dispersing pigments, and Cab-0-Jet 300K, which is a carboxylic acid group-containing self-dispersing pigment (all manufactured by Cabot Corporation). Other commercially available examples of self-dispersing pigments include Cab-0-Jet 400K, 450C, 4637M, 465M, 470V, and 480V, which are phosphate group-containing self-dispersing pigments (all manufactured by Cabot Corporation).

[0025] The anionic resin is a resin that aggregates due to an aggregating agent contained in the pretreatment liquid (first treatment liquid) described below, and is preferably a binder resin for fixing the pigment to the fabric. The anionic resin is preferably a water-dispersible resin (resin particles). The water-dispersible resin may be a self-emulsifying resin particle having a hydrophilic group introduced therein, or a forced-emulsifying resin particle that becomes water-dispersible with the use of an external emulsifier. From the viewpoint of suppressing bleed-out, the water-dispersible resin is preferably a self-emulsifying resin particle.

[0026] Examples of the anionic group of the anionic resin include a carboxy group, a sulfonic acid group, and a phosphonic acid group.

[0027] Examples of anionic resins include (meth)acrylic resins, styrene resins, urethane resins, ester resins, etc., each having an anionic group. Preferred examples of anionic resins are (meth)acrylic resins having an anionic group and urethane resins having an anionic group, from the viewpoints of their appropriately low Tg and flexibility.

[0028] The (meth)acrylic resin having an anionic group is a polymer of a (meth)acrylic monomer or a copolymer of the (meth)acrylic monomer and another monomer copolymerizable therewith. Preferably, at least one of the (meth)acrylic monomer and the other monomer has an anionic group, and the (meth)acrylic monomer has an anionic group. The (meth)acrylic monomer is a monomer having a (meth)acryloyl group. Furthermore, (meth)acrylic is a concept that includes both methacrylic and acrylic.

[0029] Examples of (meth)acrylic monomers having an anionic group include acrylic acid and methacrylic acid. Other examples of (meth)acrylic monomers include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, and hydroxyethyl (meth)acrylate. Other examples of (meth)acrylic monomers include (meth)acrylic monomers without an anionic group such as (meth)acrylamides and (meth)acrylonitrile.

[0030] Examples of copolymerizable other monomers include ethylenically unsaturated carboxylic acids such as maleic acid and itaconic acid, styrenes such as styrene, α-methylstyrene, and vinyl toluene, and saturated vinyl fatty acids such as vinyl acetate and vinyl propionate. Other examples of copolymerizable other monomers include monofunctional monomers such as vinyl compounds such as 1,4-divinyloxybutane and divinylbenzene, and allyl compounds such as diallyl phthalate and triallyl cyanurate. Other examples of copolymerizable other monomers include polyfunctional (meth)acrylates such as diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and propylene glycol di(meth)acrylate. Other examples of copolymerizable other monomers include difunctional or higher functional monomers such as polyfunctional (meth)acrylates such as N,N'-methylenebis(acrylamide) and polyfunctional acrylamides.

[0031] From the viewpoint of lowering the Tg of the anionic resin, the (meth)acrylic monomer preferably contains acrylic acid or an alkyl acrylate. The alkyl acrylate is preferably a C4-12 alkyl acrylate, more preferably n-butyl acrylate or 2-ethylhexyl acrylate.

[0032] The urethane resin having an anionic group may be any of a polyether-type urethane resin, a polyester-type urethane resin, and a polycarbonate-type urethane resin. Furthermore, the urethane resin having an anionic group is preferably a self-emulsifying type. The self-emulsifying type urethane resin is, for example, a polyaddition product of a polyhydric alcohol having an anionic group and a polyisocyanate.

[0033] Commercially available examples of urethane resins include Takelac® W-6010 (polycarbonate-based / anionic type), Takelac® W-6020 (ether-based / anionic type), and Takelac® W-6061 (ether-based / anionic type). Other commercially available examples of urethane resins include Takelac® W-405 (ester-based / anionic type), Takelac® W-605 (ester-based / anionic type), and Takelac® WS-5000 (polyester-based / anionic type). Other commercially available examples of urethane resins include Takelac® WS-4000 (polycarbonate-based / anionic type) (both manufactured by Mitsui Chemicals, Inc.) and Superflex® 126 (ether / ester-based, anionic type) (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Other examples of commercially available urethane resins include Superflex® 130 (ether-based, anionic type) and Superflex® 150 (ether / ester-based, anionic type) (both manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). Other examples of commercially available urethane resins include Superflex® 300 (ether / ester-based, weak anionic type) and Superflex® 420 (polycarbonate-based / anionic type) (both manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). Other examples of commercially available urethane resins include Superflex® 460 (polycarbonate-based / anionic type) (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

[0034] The content of the anionic resin in the ink is preferably in the range of 1 to 20% by mass, more preferably in the range of 5 to 15% by mass, relative to the ink. When the content of the anionic resin is equal to or greater than the lower limit, the fixation of the ink to the fabric is more easily improved. When the content of the anionic resin is equal to or less than the upper limit, the fabric does not become too hard, and the texture of the fabric is less likely to be impaired. One type of anionic resin may be used alone, or multiple types may be used in combination.

[0035] Examples of commercially available anionic resins include the Acryset EMN series (Nippon Shokubai Co., Ltd.), the NeoCryl series (Kusumoto Chemicals Co., Ltd.), the Joncryl series (BASF), the Takelac series (Mitsui Chemicals, Inc.), the HUX series (ADEKA), the Evaphanol series (Nicca Chemical Co., Ltd.), and the Superflex series (Dai-ichi Kogyo Seiyaku Co., Ltd.).

[0036] The anion value is preferably within the range of 10 to 60 mgKOH / g. If the anion value is less than 10 mgKOH / g, the dispersion stability of the anionic resin in the water-soluble organic solvent may decrease. On the other hand, if the acid value is more than 60 mgKOH / g, the cationic resin may rapidly aggregate, resulting in a decrease in color development.

[0037] The content (solid content) of the anionic resin is preferably within a range of 5 to 15% by mass relative to the total amount of ink. If the content of the anionic resin is 5% by mass or more, the fixation of the pigment can be further improved. If the content of the anionic resin is 15% by mass or less, the amount of aggregates adhering to the conveyor belt is not too large, and deterioration of belt cleaning properties can be suppressed.

[0038] From the viewpoint of adaptability to the expansion and contraction of the fabric, the anionic resin preferably has a film elongation within the range of 600 to 1600%. If the film elongation is within the above range, the anionic resin can appropriately adapt to the expansion and contraction of the fabric.

[0039] The film elongation of an anionic resin can be measured as follows. First, the anionic resin is applied to a polytetrafluoroethylene sheet so that the film thickness after drying is 500 μm. The resin is then dried at 23°C for 15 hours, then at 80°C for 6 hours, and finally at 120°C for 20 minutes to obtain a resin film. The resulting resin film is then cut into a 2 cm wide and 4 cm long test piece. Using a tensile tester, the resulting test piece is stretched at a temperature of 20°C and a speed of 200 mm / min to measure the length of elongation until the test piece breaks. The film elongation is the percentage of the original length. A Tensilon Universal Tester RTC-1225A (Orientec Co., Ltd.) can be used as the tensile tester.

[0040] Silicone acrylic resin is a copolymer containing siloxane structural units and (meth)acrylic acid ester structural units.

[0041] The content of structural units derived from (meth)acrylic acid esters is not particularly limited. The content of structural units derived from (meth)acrylic acid esters is preferably in the range of 20 to 80% by mass, more preferably 30 to 70% by mass, of all structural units constituting the copolymer. If the content of structural units derived from (meth)acrylic acid esters is within the above range, for example, when the resin particles contained in the ink are (meth)acrylic resins, it is easy to appropriately reduce ΔSP. This makes it easier to gradually diffuse the lubricant to the surface of the image-formed product, and good friction resistance can be maintained over a long period of time. Furthermore, because ΔSP is not too small, the rate at which the lubricant diffuses to the surface of the image-formed product does not become too slow, making it easy to obtain good friction resistance from the beginning.

[0042] Examples of commercially available silicone acrylic resins include Chaline FE502, Chaline E-370 (Nissin Chemical Industry Co., Ltd.), and Simac US-450 (Toagosei Co., Ltd.).

[0043] Examples of water-soluble organic solvents contained in the ink include monohydric alcohols (e.g., methanol, ethanol, propanol, pentanol, hexanol, cyclohexanol, and benzyl alcohol). Other examples of water-soluble organic solvents include polyhydric alcohols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, glycerin, butylene glycol, hexanediol, pentanediol, hexanetriol, thiodiglycol, 1,2-butanediol, 1,3-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,2-heptanediol, and trimethylolpropane). Other examples of water-soluble organic solvents include polyhydric alcohol ethers (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, and tripropylene glycol monoethyl ether). Other examples of water-soluble organic solvents include amines (e.g., ethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, and triethylenetetramine), amides (e.g., formamide, N,N-dimethylformamide, and N,N-dimethylacetamide), and heterocycles (e.g., 2-pyrrolidone, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, 2-oxazolidone, and 1,3-dimethyl-2-imidazolidine). Other examples of the water-soluble organic solvent include sulfoxides (e.g., dimethyl sulfoxide) and sulfones (e.g., sulfolane). One type of water-soluble organic solvent may be used alone, or two or more types may be used in combination.

[0044] The water-soluble organic solvent preferably contains a polyhydric alcohol having a boiling point of 200° C. or higher, which makes it less likely to dry on the transport belt of the ink-jet printing apparatus described below, and therefore makes it less likely to deteriorate in belt cleaning properties.

[0045] Examples of polyhydric alcohols with a boiling point of 200°C or higher include 1,3-butanediol (boiling point 208°C), 1,6-hexanediol (boiling point 223°C), polypropylene glycol (boiling point 240°C), glycerin (boiling point 290°C), and trimethylolpropane (boiling point 295°C).

[0046] The content of the water-soluble organic solvent is not particularly limited. The content of the water-soluble organic solvent is preferably 20% by mass or more and 40% by mass or less relative to the ink. If the content of the water-soluble organic solvent is less than 20%, the viscosity increases rapidly after application, convection becomes difficult, and the silicone acrylic resin does not come out sufficiently to the surface. On the other hand, if the content of the water-soluble organic solvent is more than 40%, the water-soluble organic solvent tends to remain, and the plasticizing effect makes the anionic resin feel sticky.

[0047] Examples of water include ion-exchanged water, distilled water, and pure water. The water content is preferably in the range of 30 to 90% by mass, and more preferably in the range of 50 to 80% by mass, based on the ink.

[0048] In addition to the above-mentioned components, the ink preferably contains a pigment dispersant. The pigment dispersant is present in the ink so as to surround the surface of the pigment or is adsorbed to the surface of the pigment, forming a pigment dispersion and dispersing the pigment well. From the viewpoint of excellent pigment dispersibility, the pigment dispersant is preferably a block copolymer. Block copolymers include ABA block copolymers and ABC block copolymers. The block copolymer is preferably an ABA block copolymer consisting of two hydrophilic blocks A located at both ends of the molecule and for interacting or reacting with the flocculant, and a hydrophobic block B located between the two hydrophilic blocks.

[0049] The hydrophilic block A increases the affinity with the water-soluble organic solvent contained in the ink and contains a portion (hereinafter referred to as the "hydrophilic portion") that interacts or reacts with the coagulant attached to the fabric, and is the block that has the greater affinity with water among the blocks that make up the copolymer.

[0050] The hydrophobic block B is a portion that adsorbs to the pigment (hereinafter referred to as the "hydrophobic portion"), and is the block that has the lowest affinity for the aqueous solvent contained in the ink among the blocks that make up the copolymer.

[0051] Conventionally, pigment dispersants have been random copolymers containing hydrophilic and hydrophobic moieties at random. Because random copolymers contain hydrophobic moieties at random, they are unable to bond continuously with the pigment. Therefore, the copolymers are easily peeled off from the pigment due to the shear force generated by ink circulation. Therefore, even if the pigment dispersant is crosslinked with a crosslinking agent, it is difficult to improve the fastness of the image-formed product. However, by using a block copolymer as the pigment dispersant, the pigment dispersant is less likely to peel off from the pigment, and the crosslinking between the pigment dispersant and the crosslinking agent can further improve the wet rub fastness and wash fastness of the image-formed product.

[0052] Furthermore, block copolymers can maintain dispersibility in water-soluble organic solvents while reducing the risk of crosslinking and aggregation between pigment dispersants in the ink, resulting in improved storage stability, ejection stability, and image quality. Furthermore, because they can prevent aggregation of the pigment dispersant in the ink, the pigment dispersant is uniformly applied to the fabric surface even after the ink is ejected. This reduces the risk of localized crosslinking reactions with the crosslinking agent, preventing localized deterioration of texture and helping to maintain the texture of the fabric.

[0053] The hydrophilic block A contains a structural unit derived from a monomer having a hydrophilic group (hereinafter also referred to as "hydrophilic monomer"). Examples of the hydrophilic functional group include a hydroxyl group, a carboxyl group, an amino group, a ketone group, a sulfonic acid group, and an oxyalkylene moiety of an alkylene oxide-modified compound. The hydrophilic block A contains at least one functional group (such as a hydroxyl group, a carboxyl group, an amino group, or a sulfonic acid group) having a hydrogen atom bonded to a nitrogen atom or an oxygen atom, in order to undergo a crosslinking reaction with a crosslinking agent.

[0054] Examples of hydrophilic monomers constituting the hydrophilic block A include monomers containing a carboxy group or an acid anhydride group, monomers containing a sulfonic acid group, and ethylene oxide-modified (meth)acrylic acid ester monomers. Examples of monomers containing a carboxy group or an acid anhydride group include unsaturated polycarboxylic acids such as (meth)acrylic acid and maleic acid, and monomers containing a carboxy group or an acid anhydride such as maleic anhydride. Examples of monomers containing a sulfonic acid group include styrene sulfonic acid and 4-(methacryloyloxy)butyl sulfonic acid. Examples of ethylene oxide-modified (meth)acrylic acid ester monomers include ethylene oxide-modified (meth)acrylic acid alkyl esters. From the viewpoint of imparting appropriate water solubility to the hydrophilic block A, (meth)acrylic acid is preferred as the hydrophilic monomer.

[0055] The content of the structural units derived from hydrophilic monomers in the hydrophilic block A is higher than the content of the structural units derived from hydrophilic monomers in the hydrophobic block B. Specifically, the content of the structural units derived from hydrophilic monomers in the hydrophilic block A is preferably 10% by mass or more relative to the total mass of the hydrophilic block A. When the content of the hydrophilic monomers in the hydrophilic block A is 10% by mass or more, dispersibility in aqueous solvents is likely to be further improved. From the same viewpoint, the content is more preferably 15 to 80% by mass.

[0056] The content of structural units derived from hydrophilic monomers in the hydrophobic block B is lower than the content of structural units derived from hydrophilic monomers in the hydrophilic block A. For example, when a block copolymer includes two hydrophilic blocks A and one hydrophilic block B, the content of structural units derived from hydrophilic monomers in the hydrophobic block B is lower than that in either of the two hydrophilic blocks A. Specifically, the content of structural units derived from hydrophilic monomers in the hydrophobic block B is preferably less than 10% by mass, and more preferably 5% by mass or less, relative to the hydrophobic block B.

[0057] The hydrophilic block A may further contain a structural unit derived from a monomer other than the hydrophilic monomer. Examples of the other monomer include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate and tert-butyl (meth)acrylate; and monomers containing an aromatic ring group or an alicyclic hydrocarbon group, which will be described later.

[0058] The content of the hydrophobic block B in the ABA block copolymer is preferably 10 to 80% by mass, more preferably 20 to 80% by mass, based on the total mass of the block copolymer. When the content is 10% by mass or more, the content of the hydrophilic block A is low (or the molecular weight is small), which makes it easier to suppress crosslinking and aggregation. When the content is 80% by mass or less, the content of the hydrophilic block A is high (or the molecular weight is large), which makes it easier to increase the affinity for aqueous solvents.

[0059] The content of the hydrophilic block A is preferably 150% by mass or less relative to the content of the hydrophobic block B. This allows the length of each hydrophilic block A to be appropriately shortened, making it more difficult for crosslinking aggregation to occur.

[0060] The hydrophobic block B preferably contains a structural unit derived from a monomer having a hydrophobic functional group (hereinafter also referred to as a "hydrophobic monomer"). Examples of the monomer having a hydrophobic functional group include a monomer containing an aromatic ring group or an alicyclic hydrocarbon group.

[0061] Examples of aromatic ring-containing monomers include (meth)acrylates having aromatic ring groups, such as benzyl (meth)acrylate, phenyl (meth)acrylate, and phenoxyethyl (meth)acrylate. Other examples of aromatic ring-containing monomers include aromatic monomers such as styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2-hydroxymethylstyrene, and 1-vinylnaphthalene. The aromatic ring-containing monomer is preferably a monomer having an aromatic ring group having 6 to 15 carbon atoms.

[0062] Examples of monomers having an alicyclic alkyl group include cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate, bornyl (meth)acrylate, and isobornyl (meth)acrylate. Other examples of monomers having an alicyclic alkyl group include (meth)acrylates having an alicyclic alkyl group, such as dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. The monomer having an alicyclic alkyl group is preferably a monomer having an alicyclic alkyl group having 6 to 15 carbon atoms.

[0063] From the viewpoint of improving the adsorption to the pigment, the hydrophobic monomer is preferably a monomer having an aromatic ring group with 6 to 15 carbon atoms, such as benzyl (meth)acrylate.

[0064] The content of the structural units derived from hydrophobic monomers in the hydrophobic block B is preferably 10% by mass or more, and more preferably within the range of 15 to 100% by mass, relative to the hydrophobic block B.

[0065] The hydrophobic block B may further contain a structural unit derived from a monomer other than the hydrophobic monomer. Examples of the other monomer include the above-mentioned (meth)acrylic acid alkyl ester and the above-mentioned hydrophilic monomer.

[0066] To further improve the dispersibility of the pigment, the molecular weight distribution (PDI) = (weight average molecular weight (Mw) of the block copolymer) / (number average molecular weight (Mn) of the block copolymer) is preferably 2.0 or less. The weight average molecular weight (Mw) and number average molecular weight (Mn) can be determined by gel permeation chromatography (GPC).

[0067] The weight-average molecular weight of the block copolymer is preferably in the range of 7,000 to 21,000, more preferably in the range of 10,000 to 20,000. When the weight-average molecular weight is 7,000 or more, the dispersibility of the pigment in aqueous solvents is more easily improved. When the weight-average molecular weight is 21,000 or less, the bond points that interact or react with the crosslinking agent and / or flocculant attached to the fabric are not too long. This allows the pigment dispersant to bond intermittently with the crosslinking agent and / or flocculant, making the fabric less likely to become stiff and improving the texture. The weight-average molecular weight of the block copolymer can be measured using the same method as described above.

[0068] The acid value of the block copolymer is, for example, preferably in the range of 40 to 400 mgKOH / g, more preferably in the range of 40 to 300 mgKOH / g, and even more preferably in the range of 40 to 190 mgKOH / g. When the acid value is 40 mgKOH / g or more, the hydrophilicity of the pigment dispersant is increased, thereby further improving the dispersibility of the pigment. Furthermore, when the acid value is less than 400 mgKOH / g, excessive increase in the hydrophilicity of the pigment dispersant is further suppressed, thereby further improving the water resistance of the resulting image-formed product. The acid value can be measured in accordance with the measurement method of JIS K0070:1992.

[0069] The content of the block copolymer is preferably in the range of 5 to 90% by mass, more preferably 15 to 80% by mass, relative to the pigment. When the content is 5% by mass or more, the dispersibility of the pigment in the water-soluble organic solvent can be further improved. When the content is 90% by mass or less, an excessive increase in the viscosity of the ink due to the inclusion of an excess of block copolymer can be further suppressed.

[0070] The method for synthesizing the block copolymer is not particularly limited, but for example, it can be obtained by sequentially polymerizing monomers that constitute the blocks by living radical polymerization.

[0071] The crosslinking agent reacts with hydrophilic functional groups (such as hydroxyl groups, carboxyl groups, amino groups, and sulfonic acid groups) in the pigment dispersant or fabric, which have hydrogen atoms bonded to nitrogen or oxygen atoms, thereby improving wet friction fastness and washing fastness.

[0072] The crosslinking agent contains at least one compound selected from the group consisting of vinyl ether compounds, epoxy compounds, carbodiimide compounds, oxazoline compounds, isocyanate compounds, and aziridine compounds.

[0073] The crosslinking agent may be synthesized using a known technique or may be a commercially available product. Examples of the crosslinking agent include the crosslinking agents described in paragraphs 0130 and 0235 of JP-A-2020-2220 and paragraphs 0066 to 0073 of JP-A-2020-203965.

[0074] Examples of the vinyl ether compound include 1,4-butanediol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, and dipentaerythritol hexavinyl ether.

[0075] Examples of epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, etc. Examples of commercially available epoxy compounds include the Denacol series (Nagase ChemteX Corporation).

[0076] Examples of the carbodiimide compound include carbodiimide, N,N'-dimethylcarbodiimide, N-ethyl,N'-isopropylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-diacetylcarbodiimide, N,N'-bis(2-propene)-carbodiimide, N,N'-dipyrrolidylcarbodiimide, N,N'-diethoxycarbodiimide, bis(trimethylsilyl)carbodiimide, 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide metho-p-toluenesulfonate, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, calcium cyanamide, and polymers having a carbodiimide structure in the main chain or side chain. Examples of commercially available carbodiimide compounds include Carbodilite (Nisshinbo Chemical Inc.).

[0077] Examples of oxazoline compounds include 2-oxazoline, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-(n-propyl)-2-oxazoline, 2-(isopropyl)-2-oxazoline, 2-cyclohexyl-2-oxazoline, 2-phenyl-2-oxazoline, 2-pyrrolidyl-2-oxazoline, 2-acetyl-2-oxazoline, 2-(2-propene)-2-oxazoline, 4,5-dimethyl-2-oxazoline, 2,4,4-trimethyl-2-oxazoline, 5-phenyl-2-(2-propynylamino)-2-oxazolin-4-one, 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one, and polymers having an oxazoline structure in the main chain or side chain. Examples of commercially available oxazoline compounds include the Epocross series (Nippon Shokubai Co., Ltd.).

[0078] Examples of isocyanate compounds include phenylene diisocyanate, cyclohexane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, bis(isocyanatomethyl)cyclohexane, norbornene diisocyanate, lysine diisocyanate, polymers of the above diisocyanates, and reaction products of 1 mole of diol and 2 moles of diisocyanate. Furthermore, to enhance stability in solvents containing water, blocked isocyanates stabilized by masking the isocyanate group with a blocking agent are preferably used. Commercially available examples of blocked isocyanates include the Meikanate series (Meisei Chemical Industry Co., Ltd.).

[0079] Examples of the aziridine compound include trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarbosamide), N,N'-hexamethylene-1,6'-bis(1-aziridinecarbosamide), and N,N'-toluene-2,4'-bis(1-aziridinecarbosamide). Examples of commercially available products include the Chemitite series (Nippon Shokubai Co., Ltd.).

[0080] Furthermore, from the viewpoint of improving storage stability and wet rub fastness, epoxy compounds, oxazoline compounds, and isocyanate compounds are preferred as crosslinking agents. From the viewpoint of not only improving storage stability and wet rub fastness but also achieving good image quality, epoxy compounds and isocyanate compounds are more preferred. From the viewpoint of not only improving storage stability, wet rub fastness, and image quality but also achieving good texture, isocyanate compounds are even more preferred. Epoxy compounds and isocyanate compounds not only form crosslinked structures with pigment dispersants, but also effectively crosslink with hydrophilic functional groups contained in the fabric. This further improves wet heat fastness. Furthermore, epoxy compounds and isocyanate compounds have high affinity with additives such as coagulants contained in inks, and are less likely to interfere with the wetting and spreading of the ink. This can suppress uneven pigment concentration and improve image quality.

[0081] The content of the crosslinking agent is preferably in the range of 0.1 to 4.0% by mass, more preferably 0.5 to 2.0% by mass, based on the total mass of the ink. By setting the content to 0.1% by mass or more, a sufficient crosslinked structure is formed, thereby improving wet rub fastness. By setting the content to 4.0% by mass or less, both wet rub fastness and texture can be achieved.

[0082] The ink may further contain other components as necessary, examples of which include surfactants, preservatives, antifungal agents, and pH adjusters.

[0083] The surfactant can reduce the surface tension of the ink and increase the wetting ability of the ink to the fabric. The type of surfactant is not particularly limited. Examples of the surfactant include acetylene glycol surfactants, silicone surfactants, and fluorine surfactants.

[0084] Examples of preservatives or antifungal agents include aromatic halogen compounds (eg, Preventol CMK), methylene dithiocyanate, halogen-containing nitrogen-sulfur compounds, and 1,2-benzisothiazolin-3-one (eg, PROXEL GXL).

[0085] Examples of pH adjusters include citric acid, sodium citrate, hydrochloric acid, sodium hydroxide, and the like.

[0086] [Composition of post-processing liquid (second processing liquid)] In this embodiment, the post-treatment liquid contains an anionic resin and a silicone acrylic resin. The anionic resin and the silicone acrylic resin may be the same as those contained in the ink composition. The content of the anionic resin in the post-treatment liquid is preferably within a range of 5 to 15% by mass. The content of the silicone acrylic resin in the post-treatment liquid is preferably within a range of 0.1 to 2.0% by mass.

[0087] The post-treatment solution may further contain other components as necessary, such as surfactants, preservatives, antifungal agents, and pH adjusters.

[0088] [Composition of pre-treatment liquid (first treatment liquid)] The pretreatment liquid contains a flocculant and an organic solvent.

[0089] The flocculant aggregates the components contained in the ink and post-treatment liquid (second treatment liquid). The mechanism by which the pigment or resin aggregates or precipitates is not particularly limited. The mechanism by which the pigment or resin aggregates or precipitates may be an electrical reaction (reaction between anionic groups and cationic groups) or an action due to a change in pH.

[0090] The type of aggregating agent may be a substance having a cationic group (cationic substance) or a substance having an anionic group (anionic substance), depending on the type of resin contained in the ink or post-treatment liquid. It is preferable that the aggregating agent contains a cationic substance.

[0091] Examples of the cationic substance include polyvalent metal salts, organic acids, cationic resins, and cationic surfactants. The cationic substance is preferably a polyvalent metal salt, an organic acid, or a cationic resin from the viewpoint of excellent reactivity with the pigment and resin particles contained in the ink.

[0092] Polyvalent metal salts are water-soluble compounds containing divalent or higher polyvalent metal ions and associated anions. Examples of polyvalent metal ions include Ca. 2+ , Cu 2+ , Ni 2+ , Mg 2+ , Zn 2+ , Ba 2+ Divalent metal ions such as Al 3+ , Fe 3+ , Cr 3+ Examples of anions include trivalent metal ions such as Cl - , I - , Br - , SO4 2- , ClO3 - , NO3 - , and HCOO - , CH3COO - The polyvalent metal salts are preferably calcium salts and magnesium salts, and more preferably magnesium nitrate and calcium chloride.

[0093] The organic acid is a carboxylic acid having 1 to 6 carbon atoms. Examples of the organic acid include acetic acid, propionic acid, pantothenic acid, ascorbic acid, citric acid, malic acid, lactic acid, tartaric acid, succinic acid, and gluconic acid.

[0094] Examples of cationic resins include polyamines, diallylamine hydrochloride polymers, diallylamine polymers, methyldiallylamine hydrochloride polymers, methyldiallylamine amidosulfate polymers, methyldiallylamine acetate polymers, diallyldimethylammonium chloride polymers, diallylmethylethylammonium ethylsulfate polymers, amine-epichlorohydrin condensation polymers, poly-2-hydroxypropyldimethylammonium chloride, dimethylamine-ethylenediamine-epichlorohydrin condensates, and dimethylamine-ammonia-epichlorohydrin condensates. The water-soluble cationic resins may be used alone or in combination.

[0095] Examples of commercially available cationic resins include MPT-60 (Mitsubishi Pencil Co., Ltd.), Unisense KHE100L, Unisense FPA101L (all from Senka Corporation), PAS-M-1L (Nittobo Medical Co., Ltd.), PE-30, PAS-22SA-40, and PAS-J-81L (all from Yokkaichi Chemical Co., Ltd.).

[0096] The molecular weight of the cationic resin is from 500 to 4000, and more preferably from 600 to 3000. If the molecular weight of the cationic resin is less than 500, the cationic resin will migrate from the fabric, causing dye migration and staining. On the other hand, if the molecular weight of the cationic resin is more than 4000, the cationic resin will be less likely to fuse to the fabric, and wet rubbing fastness will be impaired.

[0097] The content of the flocculant in the pretreatment liquid is not particularly limited, but the content of the flocculant in the pretreatment liquid is preferably within a range of 0.5 to 10% by mass relative to the pretreatment liquid.

[0098] The water-soluble organic solvent can be the same as the water-soluble organic solvent contained in the ink. The water-soluble organic solvent preferably contains a polyhydric alcohol with a boiling point of 200°C or higher. This makes it less likely to dry on the transport belt of the inkjet printing device described below, and therefore less likely to deteriorate belt cleaning properties. Examples of polyhydric alcohols with a boiling point of 200°C or higher include 1,3-butanediol (boiling point 208°C), 1,6-hexanediol (boiling point 223°C), polypropylene glycol (boiling point 240°C), glycerin (boiling point 290°C), and trimethylolpropane (boiling point 295°C).

[0099] The pretreatment liquid may further contain other components as needed, as long as the effects of the present invention are not impaired. Examples of other components include surfactants, preservatives, and pH adjusters.

[0100] As described above, in this embodiment, an example has been shown in which the ink composition and the post-treatment liquid contain a silicone acrylic resin. However, the silicone acrylic resin may be contained only in the ink composition. In this case, the post-treatment liquid contains only an anionic resin. Alternatively, the silicone acrylic resin may be contained only in the post-treatment liquid. In this case, the ink composition contains a pigment, an anionic resin, a water-soluble organic solvent, and water.

[0101] [Fabric] The fabric is not particularly limited, and examples of the fabric include natural fibers (including natural cellulose fibers, hemp, wool, and silk), synthetic cellulose fibers (including regenerated cellulose fibers such as rayon, and semi-synthetic cellulose fibers such as acetate), vinylon fibers, nylon fibers, acrylic fibers, polyurethane fibers, and polyester fibers.

[0102] The fabric may be any of the above fibers in the form of woven fabric, nonwoven fabric, knitted fabric, etc. The fabric may also be a blended woven fabric or blended nonwoven fabric of two or more types of fibers.

[0103] [Inkjet printing method] 2, the inkjet printing method of the present invention includes a step (S110) of forming a wet image and a step (S120) of forming a dry image. Here, "wet state" refers to a state in which liquid remains on the fabric. Also, "dry state" refers to a state in which no liquid remains on the fabric.

[0104] In the step (S110) of forming a wet image, an ink composition is ejected onto a fabric to form a wet image. In this step, only the ink composition may be ejected onto the fabric, or the pretreatment liquid and the ink composition may be ejected consecutively, or the pretreatment liquid, ink, and posttreatment liquid may be ejected consecutively onto the fabric. Here, a case where the pretreatment liquid, ink, and posttreatment liquid are ejected consecutively onto the fabric will be described.

[0105] Here, "successively ejecting" means that there is no step such as a drying step between ejecting the pretreatment liquid and the ink onto the same location. Note that it is permissible for some of the volatile components of the pretreatment liquid to volatilize by natural drying before applying the ink composition.

[0106] In the present invention, the pre-treatment liquid, ink, and post-treatment liquid are successively ejected onto the fabric, and the pre-treatment liquid, ink composition, and post-treatment liquid are applied wet-on-wet, which makes it difficult for the texture of the fabric to be impaired. This is because, in the wet-on-wet case, the components of each treatment liquid are in close contact with each other, which makes them more likely to aggregate before penetrating into the yarns that make up the fabric. By aggregating before penetrating into the yarns, the fibers that make up the yarns are not bonded together, thereby preventing deterioration of the texture.

[0107] The order in which the pretreatment liquid and the ink composition are applied is not particularly limited. From the viewpoint that the water-soluble cationic resin contained in the pretreatment liquid functions as an ink-receiving layer, it is preferable to apply the pretreatment liquid first. The pretreatment liquid and the ink composition may be applied simultaneously.

[0108] The method for applying the pretreatment liquid and the ink composition is not particularly limited. The method for applying the pretreatment liquid and the ink composition may be the same or different. Examples of the application method include a spray method, a mangle method (a pad method or a dipping method), a coating method, and an inkjet method. When high-precision printing is to be performed, the inkjet method is preferred as the method for applying the pretreatment liquid and the ink composition.

[0109] The amount of the pretreatment liquid to be applied is not particularly limited, and is adjusted depending on the content of the water-soluble cationic resin in the pretreatment liquid, the amount of the ink composition to be applied, the type of fabric, etc. From the viewpoint of reducing aggregates that adhere to the conveyor belt, it is preferable that the amount of the pretreatment liquid to be applied is smaller than the water retention capacity of the fabric, in order to suppress strike-through of the pretreatment liquid through the fabric.

[0110] The amount of ink composition applied is not particularly limited and can be adjusted depending on the pigment content of the ink composition, the density of the image to be printed, the type of fabric, etc. From the viewpoint of reducing aggregates adhering to the conveyor belt, it is preferable that the amount of ink composition applied is smaller than the water retention capacity of the fabric in order to suppress strike-through of the ink composition through the fabric.

[0111] In the step (S120) of forming a dry image, the pre-treatment liquid, the ink composition, and the post-treatment liquid applied to the fabric are fixed to the fabric. Specifically, the wet image is irradiated with infrared light to form a dry image.

[0112] [Configuration of inkjet printing device] Next, an ink-jet printing apparatus used in the ink-jet recording method of this embodiment will be described.

[0113] FIG. 1 is a schematic diagram showing the configuration of an inkjet printing apparatus 10. As shown in FIG.

[0114] As shown in FIG. 1, the inkjet printing apparatus 10 includes a belt conveying section 20, an image forming section 30, a conveyor belt cleaning section 40, and a drying section 50.

[0115] In the belt conveying section 20, an endless conveying belt 23 of a predetermined width is stretched over a driving roller 21 and a driven roller 22 that are arranged in parallel with each other at a predetermined interval. The surface (upper surface) of the conveying belt 23 stretched over the driving roller 21 and the driven roller 22 serves as a loading surface on which the fabric P is placed in close contact. An adhesive called a ground adhesive may be applied to the surface of the conveying belt 23 to ensure that the fabric P is in close contact during conveyance. The driving roller 21 is driven to rotate by a sub-scanning motor (not shown).

[0116] In the belt conveying section 20, the driving roller 21 is rotated at a predetermined speed in the counterclockwise direction (see arrow) in FIG. 1 by the rotational drive of the sub-scanning motor. As a result, the conveying belt 23 stretched between the driving roller 21 and the driven roller 22 rotates and moves. By this operation, the fabric P placed on the surface of the conveying belt 23 is conveyed in the direction of arrow A in FIG. 1, which is the sub-scanning direction.

[0117] The fabric P may be in the form of a sheet cut to a predetermined size, or may be in the form of a continuous length continuously unwound from a roll.

[0118] In the case of an inkjet system, the image forming unit 30 is composed of multiple inkjet heads arranged at predetermined intervals above the surface of the conveyor belt 23 on which the fabric P is placed. In this embodiment, the image forming unit 30 has a first inkjet head for ejecting a pre-treatment liquid, a second inkjet head for ejecting an ink composition, and a second inkjet head for ejecting a post-treatment liquid. The multiple inkjet heads eject the treatment liquid from numerous nozzles provided on their lower surfaces onto the fabric P conveyed by the conveyor belt 23, in accordance with the inkjet textile printing method. In this way, an image in a desired wet state is formed on the fabric P.

[0119] The image forming unit 30 may be a shuttle type mounted on a carriage and reciprocating in a main scanning direction perpendicular to the conveyance direction of the intermittently conveyed fabric P. In this case, the conveyor belt 23 is controlled by the rotational drive of the drive roller 21 so as to perform intermittent operation of repeating a standby state and a driving state during image formation. Alternatively, the image forming unit 3 may be a line type fixedly suspended across the width of the conveyor belt 23 and forming images by ejecting ink droplets onto the continuously conveyed fabric P. In this case, the conveyor belt 23 is controlled by the rotational drive of the drive roller 21 so as to move (rotate) continuously during image formation.

[0120] The conveyor belt cleaning unit 40 is disposed below the belt conveying unit 20. In the conveyor belt cleaning unit 40, a plurality of cleaning means and the like are provided in order along the moving direction of the conveyor belt 23.

[0121] The conveyor belt cleaning unit 40 shown in FIG. 1 includes a water sprinkler pipe 41, a brush roller 42, a cleaning blade 43, a cleaning sponge 44, and a heating unit 45.

[0122] The sprinkler pipe 41 is suspended across the entire width of the conveyor belt 23. A large number of nozzles (not shown) are arranged along the length of the sprinkler pipe 41 at a position facing the surface of the conveyor belt 23. A cleaning liquid is supplied to the sprinkler pipe 41 via a sprinkler tube 41a by driving a sprinkler pump (not shown). The sprinkler pipe 41 sprays the supplied cleaning liquid from the nozzles onto the surface of the conveyor belt 23, thereby cleaning foreign matter adhering to the surface of the conveyor belt 23.

[0123] The brush roller 42 is formed in a roller shape by burying multiple brush bundles, each consisting of a bundle of brush bristles, around a rotating shaft that spans the entire width of the conveyor belt 23. The tips of the brush bundles are constantly in contact with the surface of the conveyor belt 23 downstream in the direction of rotation of the conveyor belt 23 from the position where the sprinkler pipe 41 sprays water. The brush roller 42 rotatably contacts the surface of the conveyor belt 23 and removes foreign matter, such as aggregates, remaining on the surface of the conveyor belt 23. Specifically, the brush roller 42 rotates at a predetermined speed in the same direction as the rotation direction of the drive roller 21 based on the power of a brush drive unit (not shown). This causes the brush roller 42 to move in a direction opposite the direction of movement of the conveyor belt 23, rubbing the tips of the brush bundles against the surface of the conveyor belt 23. This action causes the brush roller 42 to remove foreign matter that was washed away by the spraying of cleaning liquid from the sprinkler pipe 41, which is located upstream in the direction of movement of the conveyor belt 23.

[0124] A cleaning tub (not shown) for storing cleaning liquid may be provided below the brush roller 42. In this case, the lower part of the brush roller 42 is partially immersed in the cleaning liquid, and the cleaning liquid is stirred up as the brush roller 42 rotates, thereby enhancing the effect of removing foreign matter. The cleaning liquid in the cleaning tub may be supplied to the sprinkler pipe 41 via a sprinkler tube 41a. In this case, the cleaning liquid sprayed onto the surface of the conveyor belt 23 and dripping thereon is collected again in the cleaning tub and reused.

[0125] The cleaning blade 43 is provided downstream of the brush roller 42 in the rotation direction of the conveyor belt 23. The cleaning blade 43 is formed in a flat plate shape using, for example, an elastic material such as rubber, a PET sheet, or a straight brush, and is stretched across the entire width of the conveyor belt 23. The cleaning blade 43 is configured so that its tip can come into contact with or be separated from the surface of the conveyor belt 23. The cleaning blade 43 comes into contact with the surface of the conveyor belt 23 and removes foreign matter and cleaning liquid remaining on the surface of the conveyor belt 23 by scraping it off.

[0126] The cleaning sponge 44 is a porous body having water absorption properties, such as a sponge, and is stretched across the entire width of the conveyor belt 23. The surface of the cleaning sponge 44 is configured so that it can come into contact with or separate from the surface of the conveyor belt 23 downstream of the cleaning blade 43 in the rotation direction of the conveyor belt 23. By coming into contact with the surface of the conveyor belt 23, the cleaning sponge 44 absorbs and wipes away cleaning liquid remaining on the surface of the conveyor belt 23.

[0127] The heating unit 45 is a belt heater, and is provided downstream of the cleaning sponge 44 in the rotation direction of the conveyor belt 23 and upstream of the driven roller 22. The heating unit 45 heats and evaporates the cleaning liquid remaining on the surface of the conveyor belt 23.

[0128] The drying unit 50 irradiates the image in a wet state with infrared rays. The drying unit 50 is disposed downstream of the image forming unit 30 in the rotation direction of the conveyor belt 23 and upstream of the conveyor belt cleaning unit 40. The configuration of the drying unit 50 is not particularly limited as long as it can irradiate infrared rays. In this embodiment, the drying unit 50 is an infrared lamp. The drying unit 50 forms an image in a dry state by irradiating the image in a wet state with infrared rays. [Example]

[0129] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, operations were carried out at room temperature (25°C). Furthermore, unless otherwise specified, "%", "ppm", and "parts" mean "% by mass", "ppm by mass", and "parts by mass", respectively.

[0130] 1. Preparation of Pretreatment Solution <Preparation of Pretreatment Solution A-1> The following components were mixed in a 100 wt % conversion to prepare pretreatment solution A-1. MPT-60 (flocculant): 3 parts by mass Glycerin: 10 parts by mass Propylene glycol: 30 parts by mass Proxel GXL(S) (preservative): 0.05 parts by mass Olfine E1010 (Nissin Chemical Industry Co., Ltd., surfactant): 0.1 parts by mass Ion-exchanged water: 55.85 parts by mass MPT-60 (Mitsubishi Pencil Co., Ltd.) is a quaternary salt of an alkylamine-epichlorohydrin adduct.

[0131] <Preparation of Pretreatment Solutions A-2 and A-3> Pretreatment solutions A-2 and A-3 were prepared in the same manner as pretreatment solution A-1, except that the type and content of the flocculant were changed as shown in Table 1 below and the amount of ion-exchanged water was adjusted so that the total amount was 100 parts by mass. PAS-M-1L (Nittobo Medical Co., Ltd.) is a methyldiallylamine hydrochloride polymer.

[0132] Table 1 shows the compositions of pretreatment solutions A-1 to A-3.

[0133] [Table 1]

[0134] 2. Pigment Ink Preparation 2-1. Preparation of polymers for dispersants <Preparation of Block Copolymer P-1> The following components were placed in a flask equipped with an argon gas inlet tube and a stirring blade, and the mixture was reacted for 18 hours at 60° C. This produced a first prepolymer (hydrophilic block A, Mw: 6920). n-Butyl methacrylate (BMA): 138.8g Methyl methacrylate (MMA): 73.5g Methacrylic acid (MAA): 59.6g Ethyl 2-methyl-2-n-butyltellanyl propionate (BTEE) :23.3g Dibutyl ditelluride (DBDT): 14.3g 2,2'-Azobisisobutyronitrile (AIBN): 2.6g Methyl ethyl ketone: 166.1g Acetonitrile: 166.1g

[0135] An argon-substituted mixed solution of 233 g of benzyl methacrylate (BzMA), 23.3 g of MAA, 2.6 g of AIBN, 98.0 g of methyl ethyl ketone, and 98.0 g of acetonitrile was added to the first prepolymer, and the mixture was reacted at 60° C. for 9 hours, thereby obtaining a second prepolymer (Mw: 9910) containing a hydrophilic block A and a hydrophobic block B.

[0136] An argon-substituted mixed solution of 138.8 g of BMA, 73.5 g of MMA, 59.6 g of MAA, 1.3 g of AIBN, 61.1 g of methyl ethyl ketone, and 388.5 g of acetonitrile was added to the second prepolymer, and the mixture was reacted at 60° C. for 23 hours. This yielded a block copolymer P-1 (Mw: 13,800, acid value: 100) containing a hydrophilic block A, a hydrophobic block B, and a hydrophilic block A.

[0137] After the reaction was completed, 3.6 kg of methyl ethyl ketone was added to the reaction solution, and the mixture was poured into 21 L of heptane with stirring. The precipitated polymer was filtered by suction and dried to obtain a block copolymer P-1.

[0138] <Preparation of Random Copolymer P-2> A random copolymer P-2 (Mw: 15,500, acid value: 96) having a monomer composition of BMA / BzMA / MMA / MAA=36 / 30 / 19 / 15 was obtained by known radical polymerization.

[0139] 2-2. Preparation of pigment dispersion <Preparation of Pigment Dispersion O-1> 20.0 parts by mass of magenta pigment (Firstgen Super Magenta RY (CI Pigment Red 122): Dainippon Ink and Chemicals, Inc.) was mixed with block copolymer P-1, which was added in an amount of 30% by mass relative to the pigment as a pigment dispersant, 20 parts by mass of propylene glycol (PG), and 5 parts by mass of 1,2-hexanediol (1,2-HD), and ion-exchanged water was added to obtain an aqueous pigment dispersion with a pigment concentration of 20.0%.

[0140] A horizontal media disperser (Labostar Mini LMZ015, zirconia bead diameter 0.3 mm: Ashizawa Finetech Co., Ltd.) was used to prepare pigment dispersion O-1 (average particle size: 120 nm) with a pigment concentration of 20.0%. The volume-based average particle size of the pigment was measured using a particle size distribution analyzer (Zeta Nanosizer 1000HS: Malvern Instruments).

[0141] <Preparation of Pigment Dispersion O-2> Pigment dispersion B-2 (average particle size: 120 nm) with a pigment concentration of 20.0% was prepared in the same manner as pigment dispersion O-1, except that block copolymer P-1 was replaced with random copolymer P-2.

[0142] <Pigment Dispersion O-3> As the pigment dispersion O-3, Cab-0-Jet-4637M (Cabot Corporation, pigment concentration 23 wt %) was used.

[0143] 2-3. Adjustment of resin dispersion <Synthesis of Resin Dispersion Q-1> A separable flask equipped with a stirrer, temperature sensor, condenser, and argon gas inlet was charged with an activator solution prepared by dissolving 2.52 g of anionic activator (sodium dodecylbenzenesulfonate: SDS) and 0.58 g of sodium carbonate in 553 g of ion-exchanged water. The flask was stirred at 330 rpm under an argon gas flow while the internal temperature was raised to 80 °C. Meanwhile, a monomer solution was prepared by dissolving 162 g of n-butyl acrylate (BA), 54 g of methyl methacrylate (MMA), 12 g of diacetone acrylamide (DAAM), and 12 g of methacrylic acid (MAA). Next, a solution prepared by dissolving 0.16 g of polymerization initiator (potassium persulfate: KPS) in 3.06 g of ion-exchanged water was added to the solution heated to 80 °C. The monomer solution was added dropwise to this solution over 60 minutes with stirring to produce a resin particle dispersion. After the dropwise addition was completed, the mixture was heated and stirred for 120 minutes, and then a solution of 0.16 g of polymerization initiator (potassium persulfate: KPS) dissolved in 3.06 g of ion-exchanged water was added. After stirring for 60 minutes, the mixture was cooled to 40°C to obtain resin particle dispersion Q-1 (resin concentration 20 wt%).

[0144] <Resin dispersion Q-2~Q-7> Table 2 shows the product names and film elongations of resin dispersions Q-2 to Q-7. Superflex 460, Superflex 420 (both manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Impranil DLP-R, Impranil DLH (both manufactured by Sumika Covestro Urethane Co., Ltd.), Takelac (registered trademark) W-6061, and Takelac W-6010 (both manufactured by Mitsui Chemicals, Inc.) are all urethane resins.

[0145] [Table 2]

[0146] 2-4. Adjusting the ink <Preparation of Ink B-1> Ink B-1 was prepared by mixing the following components in 100 wt % equivalent. Anionic pigment dispersion O-1: 3.5 parts by mass Anionic resin particles Q-5: 10 parts by mass Chaline E-370 (Nissin Chemical Industry Co., Ltd., silicone acrylic resin) :0.5 part by mass Glycerin: 10 parts by weight Propylene glycol: 20 parts by mass Proxel GXL(S) (preservative): 0.1 parts by weight Olfin E1010 (Nissin Chemical Industry Co., Ltd., nonionic surfactant) :0.5 part by mass TEGO WET 250 (Evonik, nonionic surfactant) :0.1 part by mass Ion-exchanged water: 54.3 parts by mass

[0147] <Preparation of Inks B-2 to B-11> Inks B-2 to B-11 were prepared in the same manner, except that the type of pigment dispersion, the type and content of anionic resin particles, the type and content of silicone acrylic resin, and the type and content of crosslinking agent were changed as shown in Table 3, and the amount of ion-exchanged water was adjusted so that the total amount was 100 parts by mass.

[0148] Table 3 shows the type of pigment dispersion, the type and content of the anionic resin, the type and content of the silicone acrylic resin, and the type and content of the crosslinking agent.

[0149] [Table 3]

[0150] 3. Adjustment of post-processing solution <Preparation of post-treatment solution C-1> The following components were mixed in a 100 wt % conversion to prepare post-treatment liquid C-1. Resin dispersion Q-5: 10 parts by mass Chaline E-370 (Nissin Chemical Industry Co., Ltd., silicone acrylic resin) :0.5 part by mass Glycerin: 10 parts by weight Propylene glycol: 20 parts by mass Proxel GXL(S) (preservative): 0.1 parts by weight Olfine E1010 (Nissin Chemical Industry Co., Ltd., surfactant): 0.1 parts by mass Ion-exchanged water: 59.30 parts by mass

[0151] <Preparation of post-treatment solutions C-2 to C-8> Post-treatment liquids C-2 to C-8 were prepared in the same manner as post-treatment liquid C-1, except that the type of resin dispersion and the type of silicone acrylic resin were changed as shown in Table 4 so that the total amount was 100 parts by mass.

[0152] Table 4 shows the types of resin dispersions and silicone acrylic resins.

[0153] [Table 4]

[0154] 4. Imaging and Evaluation 4-1. [Textile image formation] Cotton satin (100% cotton: product name 60 Cotton Satin, manufactured by Okadaya Co., Ltd.) was prepared as the fabric. The inkjet head printing method in the inkjet printing device was a scan type, and a Konica Minolta Pro120 equipped with an inkjet head KM1024i (Konica Minolta, Inc.) was used. Using a first inkjet head filled with a pretreatment liquid, a second inkjet head filled with an ink composition, and a third inkjet head filled with a posttreatment liquid, ink was ejected onto the fabric by inkjet printing, followed by drying, to obtain a printed image. The pretreatment liquid, ink composition, and posttreatment liquid were ejected from each inkjet head at 540 dpi in the main scanning direction and 720 dpi in the sub-scanning direction. dpi refers to the number of ink droplets (dots) per 2.54 cm. The ejection frequency was 22.4 kHz. The image was printed in a forward pass and then a backward pass, creating a two-pass print (two scans). The substrate was then dried by the following drying method to obtain a 200 mm x 200 mm 100% solid printed image. The amount of the pre-treatment liquid, ink composition, and post-treatment liquid applied was 15 g / m 2 , 15g / m 2 and 15 g / m 2 These adhesion amounts were determined from the ejection amounts of the pre-treatment liquid, the ink composition, and the post-treatment liquid.

[0155] <Drying method 1> Drying was carried out using a near-infrared dryer (air-cooled (room temperature air blowing)) equipped with ultra-short wavelength infrared heaters (2.5kW x 3) manufactured by Adphos, at an irradiation distance of 60mm, with a power density of 30kW / m2 and irradiation time of 1 minute.

[0156] <Drying method 2> Drying was carried out in a belt conveying dryer at 150°C for 1 minute.

[0157] [Evaluation of texture] Sensory evaluation of the texture of the printed fabric was carried out by five people. Based on the number of people who felt that the printed fabric was stiffer than the unprinted fabric, the texture of the fabric was evaluated according to the following criteria: A: The number of people who felt that the fabric became stiffer after printing was 0 to 1. B: Two or three people felt that the fabric became stiffer after printing. C: Four people felt that the fabric was stiffer after printing. D: Five people felt that the fabric was stiffer after printing.

[0158] [Stickyness rating] The resulting image-formed product was folded in half so that the image-formed surface was on the inside, a 1 kg weight was placed on top, and after 5 minutes the weight was removed. The area where the weight was placed was pinched to observe whether the image surfaces were sticking together due to stickiness, and the result was evaluated according to the following criteria. A: The image forming surfaces did not stick together and peeled off easily. B: The image-forming surfaces stick together slightly, but peel off after 30 seconds. C: The image-forming surfaces stick together and do not separate even after 30 seconds. A and B are within the acceptable range.

[0159] Table 5 shows the compositions of the pre-treatment liquid, ink composition, and post-treatment liquid.

[0160] [Table 5]

[0161] The evaluation results are shown in Table 6.

[0162] [Table 6]

[0163] As shown in Tables 5 and 6, in Examples 1 to 12, which used ink compositions containing a cationic polymer in the pretreatment liquid, an anionic resin and a silicone acrylic resin with a film elongation of 600 to 1600%, particularly 700 to 1050%, and particularly a silicone acrylic resin / anionic resin ratio of 0.05 or more, and which obtained dried images by irradiating with infrared rays, the texture and stickiness were good.

[0164] On the other hand, Comparative Examples 1 to 5, in which the anionic resin film elongation was outside the range of 600 to 1600%, did not contain a silicone acrylic resin, or was not irradiated with infrared rays, had poor texture or stickiness. In particular, Comparative Examples 1 and 2, in which the film elongation was less than 600, tended to have poor texture. Furthermore, Comparative Examples 3 to 5, in which the silicone acrylic resin was not contained or which was not irradiated with infrared rays, tended to have poor stickiness due to the low proportion of silicone acrylic resin on the coating surface. [Explanation of symbols]

[0165] 1. Textile printing equipment 2 Belt conveyor 3 Image forming unit 4. Conveyor belt cleaning section 21 Drive roller 22 driven roller 23 Conveyor belt 41 Sprinkler pipe 41a Watering tube 42 Brush Roller 43 Cleaning blade 44 Cleaning sponge 45 Heating section 50 Drying section

Claims

1. a step of ejecting an ink composition containing an anionic resin and a silicone acrylic resin, each having a film elongation of 600 to 1600%, onto a fabric to form a wet image; irradiating the wet image with infrared light to form a dry image; having Inkjet printing method.

2. the ink composition contains a polyhydric alcohol having a boiling point of 200°C or higher, the content of the polyhydric alcohol relative to the total amount of the ink composition is 20% by mass or more and 40% by mass or less; The ink-jet printing method according to claim 1.

3. The ink-jet printing method according to claim 1 , wherein the anionic resin is a urethane resin.

4. The ink-jet printing method according to claim 1 , further comprising a step of applying a pretreatment liquid containing a flocculant to the fabric before the step of forming the wet image.

5. The ink-jet printing method according to claim 4 , wherein the flocculant is a substance having a cationic group.

6. the ink composition includes a block copolymer and a pigment dispersion having a pigment dispersed in the block copolymer; The block copolymer includes an ABA type block copolymer consisting of two hydrophilic blocks A arranged at both ends of the molecule and for interacting or reacting with the flocculant, and a hydrophobic block B arranged between the two hydrophilic blocks. The ink-jet printing method according to claim 4.

7. The ink-jet printing method according to claim 6 , wherein the pigment dispersion further contains a crosslinking agent.

8. The ink composition comprises an ink for forming the wet image; a post-treatment liquid for coating the wet image; and the silicone acrylic resin is contained in the ink or the post-treatment liquid; The ink-jet printing method according to claim 1 .

9. an anionic resin having a film elongation of 600 to 1600%; Silicone acrylic resin, Including, Ink composition.

10. an image forming unit for ejecting the ink composition according to claim 8 onto a fabric to form an image in a wet state; a drying section for drying the wet image by infrared drying to form a dry image; having Inkjet printing equipment.

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