Water-based ink for inkjet recording, ink set, inkjet recording device, and image forming method.

Abstract

This provides a new technology that can achieve high wash fastness when used for printing on fabric materials. [Solution] An aqueous inkjet recording ink is used to form an image on a fabric material. The aqueous inkjet recording ink comprises a pigment, a binder, and a crosslinking agent. The binder contains a polyurethane resin having a polyester skeleton. The crosslinking agent contains an oxazoline group-containing compound. The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the crosslinking agent content to the binder content is 0.15 or more.

Description

Technical Field

[0001] The present specification discloses a technique relating to an aqueous ink for inkjet recording, an ink set, an inkjet recording apparatus, and an image forming method. In particular, the present specification discloses a technique relating to an aqueous ink and the like that can be used for textile printing on fabric materials.

Background Art

[0002] Patent Document 1 discloses an aqueous ink for inkjet recording that is used for textile printing on fabrics. This aqueous ink contains a pigment, a water-dispersible resin, and a crosslinking agent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In general, since fabric materials are washed with water, textile printing on fabric materials requires maintenance of high washing fastness over a long period of time. The present specification provides a new technique that can realize maintenance of high washing fastness over a long period of time when an aqueous ink is used for textile printing on fabric materials.

Means for Solving the Problems

[0005] The aqueous ink for inkjet recording disclosed in the present specification is used for forming images on fabric materials. The aqueous ink for inkjet recording includes a pigment, a binder, and a crosslinking agent. The binder includes a polyurethane-based resin having a polyester skeleton. The crosslinking agent includes an oxazoline group-containing compound. The ratio of the content of the binder to the content of the pigment is 1.40 or more. The ratio of the content of the crosslinking agent to the content of the binder is 0.15 or more.

[0006] The above-mentioned water-based inkjet recording ink allows for suitable crosslinking of the binder, and this crosslinking makes the ester bonds of the binder less susceptible to hydrolysis. As a result, a resin coating film can be formed that achieves high wash fastness over a long period of time.

[0007] The ink set is also novel and useful. The ink set comprises the above-mentioned water-based inkjet recording ink and a pretreatment liquid. The pretreatment liquid is applied to the fabric material before forming an image on the fabric material using the water-based inkjet recording ink.

[0008] The inkjet recording device is also novel and useful. The inkjet recording device comprises an ink storage section, an ink ejection section, and an aqueous inkjet recording ink stored in the ink storage section. The inkjet recording device ejects the aqueous inkjet recording ink from the ink ejection section to form an image on a fabric material. The aqueous inkjet recording ink comprises a pigment, a binder, and a crosslinking agent. The binder contains a polyurethane resin having a polyester skeleton. The crosslinking agent contains an oxazoline group-containing compound. The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the crosslinking agent content to the binder content is 0.15 or more.

[0009] A novel and useful image forming method is also provided for forming an image on a fabric material using an inkjet recording method. This image forming method comprises an image forming step and a drying step. In the image forming step, an image is formed on the fabric material using the water-based inkjet recording ink. In the drying step, the water-based inkjet recording ink is dried by heating the fabric material on which the image has been formed. The water-based inkjet recording ink comprises a pigment, a binder, and a crosslinking agent. The binder contains a polyurethane resin having a polyester skeleton. The crosslinking agent contains an oxazoline group-containing compound. The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the crosslinking agent content to the binder content is 0.15 or more. [Brief explanation of the drawing]

[0010] [Figure 1] This shows the configuration of an inkjet recording device. [Figure 2] This shows a schematic configuration of the discharge head mounted on the carriage. [Figure 3] This shows an example of a configuration in which a pretreatment solution is applied before image formation by an inkjet recording device. [Modes for carrying out the invention]

[0011] (Water-based ink for inkjet recording) Hereinafter, an embodiment of the water-based inkjet recording ink disclosed herein will be described. Hereinafter, the water-based inkjet recording ink may be simply referred to as water-based ink. The water-based ink is used to form an image on a fabric material. Examples of fabric materials include woven fabrics, nonwoven fabrics, knitted fabrics, etc., composed of fiber materials. Examples of fiber materials include natural fibers and synthetic fibers. Examples of natural fibers include cotton, linen, wool, silk, etc. Examples of synthetic fibers include rayon, vinylon, nylon, acrylic, polyurethane, polyester, or acetate, etc. The fabric material may be a blended woven fabric or blended nonwoven fabric using two or more types selected from these. The water-based ink comprises a pigment, a binder, and a crosslinking agent.

[0012] (Pigment) The pigments are not particularly limited and include, for example, carbon black, inorganic pigments, and organic pigments. Examples of carbon black include furnace black, lamp black, acetylene black, and channel black. Examples of inorganic pigments include titanium dioxide, iron oxide-based inorganic pigments, and carbon black-based inorganic pigments. Examples of organic pigments include azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments; polycyclic pigments such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments; dye lake pigments such as basic dye-type lake pigments and acid dye-type lake pigments; nitro pigments: nitroso pigments; aniline black daylight fluorescent pigment; and others. In addition, other pigments can be used as long as they are dispersible in the aqueous phase. Specific examples of these pigments include, for example, CI Pigment Black 1, 6 and 7; CI Pigment Yellow 1, 2, 3, 12, 13, 14, 15, 16, 17, 55, 74, 78, 150, 151, 154, 155, 180, 185 and 194; CI Pigment Orange 31 and 43; CI Pigment Red 2, 3, 5, 6, 7, 12, 15, 16, 48, 48:1, 53:1, 57, 57:1, 112, 122, 123 Examples include 139, 144, 146, 149, 150, 166, 168, 175, 176, 177, 178, 184, 185, 190, 202, 209, 221, 222, 224 and 238; CI Pigment Violet 19 and 196; CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 16, 22 and 60; CI Pigment Green 7 and 36; and solid solutions of these pigments. Water-based inks may be prepared by dispersing pigments in water with a dispersant. As the dispersant, for example, a general polymer dispersant may be used, or it may be prepared in-house. Polymer dispersants include pigment dispersion resins, resin dispersants, etc. In addition, in water-based inks, the pigments may be encapsulated by polymers.

[0013] One method for dispersing pigments using pigment dispersion resins is to disperse the pigments using a dispersion apparatus. The dispersion apparatus used for dispersing pigments is not particularly limited as long as it is a general-purpose disperser, but examples include ball mills, roll mills, and sand mills.

[0014] The pigment may be a self-dispersing pigment. A self-dispersing pigment is one in which, for example, at least one of a hydrophilic functional group such as a carbonyl group, hydroxyl group, carboxylic acid group, sulfonic acid group, or phosphate group, or a salt thereof, is introduced into the pigment particles by chemical bonding, either directly or via other groups, so that it can be dispersed in water without the use of a dispersant.

[0015] Pigments may be used individually or in combination of two or more types. The pigment solid content relative to the total amount of aqueous ink (pigment solid content) is not particularly limited and can be appropriately determined based on the desired optical density or saturation. The range of pigment solid content is, for example, 0.10% to 20.00% by mass, 0.50% to 15.00% by mass, 1.00% to 10.00% by mass, and 2.00% to 8.00% by mass. The pigment solid content is the mass of the pigment only and does not include the mass of resin dispersants, etc. In other words, the pigment solid content is calculated on an effective ingredient basis.

[0016] (binder) The binder is formulated to improve the fixation and friction fastness of the pigment to the fabric by forming a resin coating on the fabric. The binder may be formulated, for example, in the form of an emulsion in an aqueous ink, or dispersed in the aqueous ink in the form of resin particles. The binder contains a polyurethane resin having a polyester skeleton.

[0017] A polyurethane-based resin having a polyester skeleton can be obtained, for example, by reacting a polyol component, a polyisocyanate component, and optionally a chain extender, a chain terminator, etc., via a known method, optionally using a urethanization catalyst. The polyol component includes, for example, a polyester polyol which is a polyol having a polyester skeleton in the molecule.

[0018] The polyester polyol includes one or more selected from the group consisting of polyester polyols obtained by subjecting a component containing a polycarboxylic acid or an esterifiable derivative thereof and a component containing a polyol to a polycondensation reaction, polyester polyols obtained by subjecting a cyclic ester to a ring-opening polymerization reaction using the component containing a polyol as an initiator, and polyester polyols obtained by copolymerization of these.

[0019] The polycarboxylic acid may be any compound having two or more carboxyl groups. Examples of the polycarboxylic acid include dicarboxylic acids and tricarboxylic acids. Examples of the polycarboxylic acid include one or more selected from aromatic polycarboxylic acids, aliphatic polycarboxylic acids, and alicyclic polycarboxylic acids. Further, examples of the polycarboxylic acid include one or more selected from saturated polycarboxylic acids and unsaturated polycarboxylic acids. The polycarboxylic acid may be an anhydride.

[0020] The esterifiable derivative of the polycarboxylic acid is, for example, an esterified product of a polycarboxylic acid and one or more of aliphatic alcohols having 1 to 4 carbon atoms and / or polyhydric alcohols having 1 to 4 carbon atoms, which is capable of forming a polyester by reacting with a polyol.

[0021] Examples of aromatic polycarboxylic acids include one or more selected from phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, halogenated phthalic acids such as tetrachlorophthalic acid and tetrabromophthalic acid, monosulfonate phthalate, monosulfonate isophthalate, monosulfonate terephthalate, and esterifiable derivatives thereof.

[0022] Examples of aliphatic polycarboxylic acids include one or more selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, polymeric fatty acids, maleic acid, fumaric acid, itaconic acid, and esterifiable derivatives thereof.

[0023] Examples of alicyclic polycarboxylic acids include one or more selected from 1,2-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, hexahydrophthalic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic acid, tricyclodecanedicarboxylic acid, tetrahydrophthalic acid or 4-methyltetrahydrophthalic acid, and esterifiable derivatives thereof. The polycarboxylic acid may be a cis isomer, a trans isomer, or a mixture of both.

[0024] The component containing one or more polycarboxylic acids or esterifiable derivatives thereof may contain a monocarboxylic acid. As the monocarboxylic acid, for example, one or more selected from acetic acid, propionic acid, benzoic acid, t-butylbenzoic acid, lauric acid, isononanoic acid, fatty acids of naturally derived oils, acrylic acid, methacrylic acid and crotonic acid can be used.

[0025] Examples of polyols include aromatic polyols, aliphatic polyols, and alicyclic polyols. Polyols may be either saturated or unsaturated. Polyols only need to have two or more hydroxyl groups; examples include diols and triols.

[0026] Examples of diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 3-methyl-1,5-pentanediol, and alkaline diols. Diol, triethylene glycol, propylene glycol, dipropylene glycol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, trimethylpentanediol, ethylbutylpropanediol, diethyloctanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-methyl-1,3-propanediol, 2-phenyl-2-methyl -1,3-propanediol, 2-propyl-2-ethyl-1,3-propanediol, 2-di-t-butyl-1,3-propanediol, 2-butyl-2-propyl-1,3-propanediol, 1-dihydroxymethyl-bicyclo[2.2.1]heptane, 2,2-diethyl-1,3-propanediol, 2,2-dipropyl-1,3-propanediol, 2-cyclohexyl-2-methyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 2,5-diethyl-2,5-hexanediol, 2-ethyl-5-methyl- Examples include one or more selected from 2,5-hexanediol, 2,4-dimethyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, 1,4-(2'-hydroxypropyl)-benzene, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octen-3,8-diol, bishydroxyethoxybenzene, xylylene glycol, bis-2-hydroxyethylene terephthalate, bisphenol A, bisphenol F, hydrogenated bisphenol A, and 1,3-(2'-hydroxypropyl)-benzene.

[0027] Examples of triols include one or more selected from trimethylolethane, trimethylolpropane, and glycerin.

[0028] The polyol-containing component may also contain a monool. A monool is a compound having one hydroxyl group, such as alcohols or phenols. Examples of monools include one or more selected from ethanol, propanol, 1-butanol, 2-butanol, t-butyl alcohol, amyl alcohol, hexanol, aliphatic alcohol, allyl alcohol, and phenol.

[0029] Polyisocyanates are compounds or derivatives thereof having two or more isocyanate groups. Examples of polyisocyanates include diisocyanates and triisocyanates. Other examples of polyisocyanates include one or more selected from aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, aromatic aliphatic polyisocyanates, and aromatic alicyclic polyisocyanates. Polyisocyanates may be blocked with a blocking agent. Derivatives of polyisocyanates may be polymerized or modified products (adducts, carbodiimides, allophanates, uretdiones, isocyanurates, biuretides, uretoimines, dimers, trimers, pentamers, heptamers, etc.).

[0030] Examples of aliphatic polyisocyanates include one or more selected from ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), ethyl ethylene diisocyanate, heptamethylene diisocyanate, dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate (2,6-diisocyanatomethyl caproate), bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

[0031] Examples of alicyclic polyisocyanates include one or more selected from isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, cyclobutane diisocyanate, cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, and 2-heptyl-3,4-bis(9-isocyanatonol)-1-pentyl-cyclohexane.

[0032] Examples of aromatic polyisocyanates include one or more selected from 2,4-tole diisocyanate, 2,6-tole diisocyanate, 4,4'-diphenylmethane diisocyanate, p-phenylenediisocyanate, m-phenylenediisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, dianisidine diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, triphenylmethane triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, dimethyltriphenylmethane tetraisocyanate, and one or more selected from polymethylene polyphenyl polyisocyanates (crude MDI, polymeric MDI) and crude tole diisocyanate (crude TDI).

[0033] Examples of aromatic aliphatic polyisocyanates include one or more selected from 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, and tetramethylxylylene diisocyanate.

[0034] As chain extenders, urethane catalysts, and chain inhibitors, those conventionally used in the manufacture of polyurethane can be used.

[0035] Commercially available polyurethane resins with a polyester backbone may be used. Examples of commercially available products include "Takelac® W-5030" and "Takelac W-5130" from Mitsui Chemicals, Inc., "Superflex® 126", "Superflex 150", "Superflex 150HS", "Superflex 170", "Superflex 210", "Superflex 300", "Superflex 500M", "Superflex 620", "Superflex 740", "Superflex 820", "Superflex 830HS", "Superflex 860", and "Superflex E-2000" from Daiichi Kogyo Seiyaku Co., Ltd., "Impranil DLP-R", "Impranil DLN-W50", and "Impranil DLP1380" from Sumika Covestro Urethane Co., Ltd., and "NeoRez® R9330", "NeoRez R9679", "NeoRez R9637", and "NeoRez R972" from DSM. These binders may be used individually or in combination of two or more types.

[0036] The binder content is adjusted as appropriate according to the pigment content as described above. Specifically, the ratio of binder content to pigment content is set to 1.40 or more in terms of solid content. The lower limit of the ratio of binder content to pigment content is 1.40 or more in terms of solid content, and may be, for example, 1.50 or more, 1.60 or more, 1.70 or more, or 1.80 or more. The upper limit of the ratio of binder content to pigment content is not particularly limited. The upper limit of this ratio may be, for example, 5.00 or less, 4.00 or less, 3.50 or less, 3.00 or less, or 2.80 or less in terms of solid content. If the ratio is 1.40 or more, a sufficient amount of binder relative to the pigment can fix the pigment to the fabric material by forming a suitable resin coating film.

[0037] The binder content relative to the total amount of water-based ink is not particularly limited. The lower limit of the binder content, in terms of solid content, is, for example, 1.00% by mass or more, 2.00% by mass or more, 2.50% by mass or more, 3.00% by mass or more, and 3.50% by mass or more. The upper limit of the binder content, in terms of solid content, is, for example, 15.00% by mass or less, 10.00% by mass or less, 9.00% by mass or less, 8.00% by mass or less, and 7.00% by mass or less. The range of the binder content can be set by appropriately combining the upper and lower limits mentioned above. The range of the binder content, in terms of solid content, is, for example, 1.00% by mass or more and 15.00% by mass or less, 2.00% by mass or more and 10.00% by mass or less, 2.50% by mass or more and 9.00% by mass or less, 3.00% by mass or more and 8.00% by mass or less, and 3.50% by mass or more and 7.00% by mass or less. If the binder content is within the above range, the pigment can be suitably fixed to the fabric material, and a high degree of frictional fastness of the resin coating can be ensured.

[0038] Furthermore, the water-based ink may contain, as a binder, other water-dispersible resins in addition to polyurethane resins having a polyester backbone. Examples of water-dispersible resins include acrylic acid resins, polycarbonate resins, styrene resins, polyester resins, and polyurethane resins having other backbones.

[0039] (Crosslinking agent) The crosslinking agent is water-soluble and is added to impart crosslinkability to the binder. The crosslinking agent includes an oxazoline group-containing compound. The oxazoline group-containing compound is a compound that contains two or more oxazoline groups in its molecule. The oxazoline group-containing compound can suitably crosslink the binder containing the polyurethane resin having the polyester skeleton described above, and can form a sufficient resin coating film. As a result, high wash fastness can be obtained.

[0040] Examples of oxazoline group-containing compounds include 2,2'-bis(2-oxazoline), 2,2'-methylene-bis(2-oxazoline), 2,2'-ethylene-bis(2-oxazoline), 2,2'-trimethylene-bis(2-oxazoline), 2,2'-tetramethylene-bis(2-oxazoline), 2,2'-hexamethylene-bis(2-oxazoline), 2,2'-octamethylene-bis(2-oxazoline), 2, Examples include 2'-ethylene-bis(4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis(2-oxazoline), 2,2'-m-phenylene-bis(2-oxazoline), 2,2'-m-phenylene-bis(4,4'-dimethyl-2-oxazoline), bis(2-oxazolinylcyclohexane) sulfide, bis(2-oxazolinylnorbornane) sulfide, and oxazoline group-containing polymers.

[0041] Among the oxazoline group-containing compounds mentioned above, water-soluble oxazoline group-containing compounds are preferred from the viewpoint of excellent crosslinking performance, and oxazoline group-containing polymers are also preferred. Oxazoline group-containing polymers can be produced by conventionally known production methods. For example, one or more addition-polymerizable oxazolines, or a monomer component including an addition-polymerizable oxazoline and a monomer copolymerizable thereto, can be used. Preferred copolymerizable monomers are monomers that do not have a functional group that reacts with the oxazoline group and are copolymerizable with the addition-polymerizable oxazoline. For example, monomers containing ethylenically unsaturated double bonds that do not have a functional group that reacts with the oxazoline group can be used. Examples include vinyl monomers such as vinyl acetate, vinyl chloride, acrylonitrile, acrylamide, and vinyl benzoate; (meth)acrylic monomers such as (meth)acrylic acid esters; styrene monomers such as styrene, α-methylstyrene, and chloromethylstyrene; and olefin monomers such as ethylene and propylene.

[0042] Examples of addition polymerizable oxazolines include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline.

[0043] Examples of water-soluble oxazoline group-containing polymers include polymers that have acrylic polymers, acrylic-styrene polymers, etc., as the main chain and contain oxazoline groups in the side chains.

[0044] Commercially available oxazoline group-containing compounds may be used. Examples of commercially available products include "Epocross (registered trademark) WS-500", "Epocross WS-700", "Epocross K-2010E", "Epocross K-2020E", and "Epocross K-2035E" manufactured by Nippon Shokubai Co., Ltd. Among these, water-soluble oxazoline group-containing compounds are preferred from the viewpoint of improving reactivity. For example, Epocross WS-500 and Epocross WS-700 are preferred.

[0045] The crosslinking agents described above may be used individually or in combination of two or more. The amount of crosslinking agent is adjusted as appropriate according to the amount of binder described above. Specifically, the ratio of the amount of crosslinking agent to the amount of binder is set to 0.15 or more in terms of solid content. The lower limit of the ratio of the amount of crosslinking agent to the amount of binder is 0.15 or more in terms of solid content, and may be, for example, 0.16 or more, 0.17 or more, 0.18 or more, or 0.19 or more. The upper limit of the ratio of the amount of crosslinking agent to the amount of binder is not particularly limited. The upper limit of this ratio may be, for example, 1.00 or less, 0.80 or less, 0.60 or less, 0.50 or less, or 0.40 or less in terms of solid content. Binders containing polyurethane resins having a polyester skeleton as described above are prone to hydrolysis of ester bonds under high temperature and high humidity, making it difficult to maintain high wash fastness over a long period of time. However, if the ratio is 0.15 or higher, a resin coating that is resistant to hydrolysis can be formed, thus maintaining long-term wash fastness.

[0046] The amount of crosslinking agent relative to the total amount of water-based ink is not particularly limited. The lower limit of the amount is, for example, 0.30% by mass or more, 0.50% by mass or more, 0.70% by mass or more, 0.80% by mass or more, and 0.90% by mass or more, on a solid content basis. The upper limit of the amount is, for example, 10.00% by mass or less, 5.00% by mass or less, 4.00% by mass or less, 3.00% by mass or less, and 2.40% by mass or less, on a solid content basis. The range of the amount can be set by appropriately combining the upper and lower limits mentioned above. The range of the amount is, for example, 0.30% by mass or more and 10.00% by mass or less, 0.50% by mass or more and 5.00% by mass or less, 0.70% by mass or more and 4.00% by mass or less, 0.80% by mass or more and 3.00% by mass or less, and 0.90% by mass or more and 2.40% by mass or less, on a solid content basis.

[0047] Furthermore, in addition to the oxazoline group-containing compound, the aqueous ink may also contain other crosslinking agents. Examples of other crosslinking agents include isocyanate group-containing compounds, carbodiimide compounds, aziridine group-containing compounds, epoxy group-containing compounds, and aqueous crosslinking agents in which hydrophilic segments are imparted to polycarbodiimide resins.

[0048] (Other ingredients) Water-based inks may further contain water, wax particles, water-soluble organic solvents, and surfactants as other components.

[0049] (water) The water is preferably deionized water or pure water. The water content relative to the total amount of water-based ink is appropriately determined according to the desired ink characteristics, etc. The range of water content is, for example, 15.00% by mass or more and 95.00% by mass or less, 35.00% by mass or more and 85.00% by mass or less, or 50.00% by mass or more and 80.00% by mass or less. The water content may, for example, be the remainder of the other components.

[0050] (wax particles) Wax particles may be added to improve the abrasion resistance of resin coatings. Wax particles contain wax. Examples of waxes include natural waxes and synthetic waxes. Wax particles may also contain components other than wax. However, from the viewpoint of improving friction fastness, the wax content in the wax particles is preferably, for example, 80.00% by mass or more and 100% by mass or less. It is more preferable that the wax particles consist only of wax.

[0051] Examples of natural waxes include petroleum-based waxes such as paraffin wax and microcrystalline wax; lignite-based waxes such as montane wax; plant-based waxes such as carnauba wax and candelilla wax; and animal and plant-based waxes such as beeswax and lanolin. Examples of synthetic waxes include polyethylene wax, polypropylene wax, oxidized polyethylene wax, polyalkylene wax, oxidized polyalkylene wax, and silicone wax. Among these, polyethylene wax and paraffin wax are preferred. The wax particles may be, for example, a wax emulsion. A wax emulsion is composed of, for example, wax particles and a dispersion medium, in which the wax particles are dispersed in the dispersion medium with a specific particle size, rather than being dissolved.

[0052] Commercially available waxes may be used. Examples of commercially available waxes include BYK-Chemie's "CERAFLOUR(registered trademark) 925", "CERAFLOUR929", "CERAFLOUR950", "CERAFLOUR991", "AQUACER(registered trademark) 497", "AQUACER498", "AQUACER507", "AQUACER515", "AQUACER526", "AQUACER531", "AQUACER537", "AQUACER539", "AQUACER552", "AQUACER593", "AQUACER1547", and "AQ Examples include "UAMAT(registered trademark) 208", "AQUAMAT 263", "AQUAMAT 272", etc.; "CHEMIPEARL(registered trademark) W100", "CHEMIPEARL W200", "CHEMIPEARL W300", "CHEMIPEARL W400", "CHEMIPEARL W500", "CHEMIPEARL W700", "CHEMIPEARL W800", "CHEMIPEARL W900" manufactured by Mitsui Chemicals, Inc.; and "HITECH E-7100S", "HITECH E-8237", "HITECH E-6314", "HITECH E-6700", "HITECH E-8010" manufactured by Toho Chemical Industry Co., Ltd. Among these, for example, anionic waxes are preferred, and from another viewpoint, oxidized high-density polyethylene wax and paraffin wax are preferred. Specifically, for example, "AQUACER 1547", "AQUACER 531", and "AQUACER 537" are preferred.

[0053] The melting point of the wax particles is not particularly limited. The melting point of the wax particles should be such that the wax particles melt to a suitable degree when the water-based ink applied to the fabric is heated and dried. Examples of melting points for wax particles include 70°C to 160°C, 90°C to 150°C, and 100°C to 140°C.

[0054] Wax particles may be used individually or in combination of two or more types. When the water-based ink contains wax particles, the amount of wax particles relative to the total amount of water-based ink is not particularly limited. The lower limit of the amount is, for example, 0.10% by mass or more, 0.20% by mass or more, 0.25% by mass or more, and 0.30% by mass or more, on a solid content basis. The upper limit of the amount is, for example, 5.00% by mass or less, 4.00% by mass or less, 3.00% by mass or less, and 2.00% by mass or less, on a solid content basis. The range of the amount can be set by appropriately combining the upper and lower limits mentioned above. The range of the amount is, for example, 0.10% by mass or more and 5.00% by mass or less, 0.20% by mass or more and 4.00% by mass or less, 0.25% by mass or more and 3.00% by mass or less, and 0.30% by mass or more and 2.00% by mass or less, on a solid content basis. If the wax particle content is within the above range, suitable abrasion resistance can be imparted to the resin coating.

[0055] (Water-soluble organic solvent) Examples of water-soluble organic solvents include wetting agents and penetrating agents.

[0056] The wetting agents are not particularly limited and include, for example, lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones such as acetone; keto alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethers such as polyalkylene glycol; polyhydric alcohols such as alkylene glycol, glycerin, trimethylolpropane, and trimethylolethane; 2-pyrrolidone; N-methyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone; and the like. Examples of polyalkylene glycols include polyethylene glycol and polypropylene glycol. Examples of alkylene glycols include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, thiodiglycol, and hexylene glycol. These wetting agents may be used individually or in combination of two or more types. Among these, polyethylene glycol is preferred, and polyethylene glycol with a degree of polymerization of 4 or higher is particularly preferred.

[0057] A single type of wetting agent may be used alone, or two or more types may be used in combination. When a water-based ink contains a wetting agent, the amount of wetting agent relative to the total amount of water-based ink is not particularly limited. The range of the wetting agent is, for example, 1.00% by mass or more and 95.00% by mass or less, 5.00% by mass or more and 80.00% by mass or less, or 10.00% by mass or more and 50.00% by mass or less. When a water-based ink contains a wetting agent, if the wetting agent content is within the above range, drying of the water-based ink during storage can be prevented, and the storage stability of the water-based ink can be improved. Furthermore, by setting the ratio of polyethylene glycol content to the total wetting agent content to 0.40 or more, the formation of a resin coating film can be further promoted. Therefore, a sufficient resin coating film can be formed, and high wash fastness can be obtained.

[0058] Examples of penetrating agents include glycol ethers. Examples of glycol ethers include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol-n-propyl ether, diethylene glycol-n-butyl ether, diethylene glycol-n-hexyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol-n-propyl ether, triethylene glycol-n-butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol-n-propyl ether, propylene glycol-n-butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol-n-propyl ether, and tripropylene glycol-n-butyl ether. Among these, triethylene glycol-n-butyl ether is preferred.

[0059] Penetrants may be used individually or in combination of two or more types. When an aqueous ink contains a penetrant, the amount of penetrant relative to the total amount of aqueous ink is not particularly limited. The range of the content is, for example, 0.10% by mass or more and 20.00% by mass or less, 0.50% by mass or more and 10.00% by mass or less, and 1.00% by mass or more and 5.00% by mass or less.

[0060] (Surfactants) The surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, silicone-based surfactants, and fluorine-based surfactants.

[0061] Examples of anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids or their salts, N-acyl methyl taurates, alkyl sulfates, polyoxyalkyl ether sulfates, alkyl sulfates, polyoxyethylene alkyl ether phosphates, rosinic acid soaps, castor oil sulfates, lauryl alcohol sulfates, alkylphenol type phosphates, alkyl type phosphates, alkylaryl sulfonates, diethyl sulfosaturates, diethylhexyl sulfosaturates, and dioctyl sulfosaturates.

[0062] Examples of nonionic surfactants include polyols, glycol ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamines, polyoxyethylene alkylamides, and acetylene glycols. Commercially available nonionic surfactants may also be used. Examples of commercially available products include "Orphin® E1004," "Orphin E1008," and "Orphin E1010" from Nisshin Chemical Industry Co., Ltd.; "Surfinol® 440," "Surfinol 465," and "Surfinol 485" from Air Products and Chemicals; and "Acetylenel® E40" and "Acetylenel E100" from Kawaken Fine Chemical Co., Ltd.

[0063] Examples of silicone-based surfactants include polyether-modified siloxanes and polyether-modified polydimethylsiloxanes. Commercially available silicone-based surfactants may also be used. Examples of commercially available products include "Dynol 960" and "Dynol 980" from Air Products and Chemicals; "Sylface (registered trademark) SAG002," "Sylface SAG005," and "Sylface SAG503A" from Nisshin Chemical Industry Co., Ltd.; "BYK (registered trademark)-345," "BYK-347," "BYK-348," "BYK-349," "BYK-3420," "BYK-3455," "BYK-3456," "LP-X23288," "LP-X23289," and "LP-X23347" from BYK-Chemie; and "TEGO (registered trademark) Twin4000" and "TEGO Wet KL245" from Evonik Tego Chemie.

[0064] Examples of fluorine-based surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in their side chains.

[0065] Surfactants may be used individually or in combination of two or more types. When an aqueous ink contains a surfactant, the amount of surfactant relative to the total amount of aqueous ink is not particularly limited. The range of the amount is, for example, 0.10% by mass or more and 20.00% by mass or less, 0.15% by mass or more and 10.00% by mass or less, and 0.20% by mass or more and 5.00% by mass or less. When an aqueous ink contains a surfactant, if the amount of surfactant is within the above range, it can impart a suitable surfactant effect to the aqueous ink.

[0066] Water-based inks may also contain conventionally known additives as needed. Examples of additives include pH adjusters, viscosity modifiers, and preservatives. Examples of viscosity modifiers include polyvinyl alcohol, cellulose, and water-soluble resins.

[0067] Water-based inks can be prepared, for example, by uniformly mixing a pigment, a binder, a crosslinking agent, water, and other components as needed, using conventionally known methods, and then removing insoluble materials using a filter or the like.

[0068] (Total solid content of water-based ink) As described above, water-based inks contain solids derived from various components. The storage stability of water-based inks can be improved by appropriately setting the total solid content relative to the total amount. In this specification, "total solid content" means the total amount of solids from the pigment, binder, crosslinking agent, and wax particles. The total solid content relative to the total amount of water-based ink is not particularly limited. The lower limit of the total solid content relative to the total amount of water-based ink is, for example, 5.00% by mass or more, 5.50% by mass or more, 6.00% by mass or more, 7.20% by mass or more, and 8.90% by mass or more. The upper limit of the total solid content relative to the total amount of water-based ink is, for example, 15.00% by mass or less, 14.00% by mass or less, 13.20% by mass or less, 12.70% by mass or less, and 11.90% by mass or less.

[0069] (Ink set) Next, the ink set disclosed herein will be described. The ink set comprises the above-mentioned water-based ink for inkjet recording and a pretreatment solution.

[0070] (Pretreatment solution) The pretreatment solution is applied to the fabric before forming an image on it using water-based inkjet recording ink. The pretreatment solution, for example, prevents the pigments contained in the water-based ink from seeping into the fabric. The pretreatment solution contains a coagulant.

[0071] (Flocculant) Coagulants are added to water-based inks to facilitate the aggregation of components, thereby suppressing ink bleeding and improving pigment fixation and color development. Examples of coagulants include organic acids, cationic compounds, and polyvalent metal salts.

[0072] Examples of organic acids include monocarboxylic acids and their salts such as formic acid, acetic acid, propionic acid, butyric acid, benzoic acid, glycolic acid, lactic acid, salicylic acid, pyrrole carboxylic acid, furoic acid, picolinic acid, nicotinic acid, thiophene carboxylic acid, levulinic acid, and coumaric acid; dicarboxylic acids and their salts or hydrogen salts such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, itaconic acid, sebacic acid, phthalic acid, malic acid, and tartaric acid; tricarboxylic acids and their salts or hydrogen salts such as citric acid and trimellitic acid; and tetracarboxylic acids and their salts or hydrogen salts such as pyromellitic acid.

[0073] Examples of cationic compounds include cationic resins and cationic surfactants.

[0074] Examples of cationic resins include resins having primary, secondary, and tertiary amine structures, and resins having quaternary ammonium salt structures. Specifically, examples include resins having structures such as vinylamine, allylamine, vinylimidazole, vinylpyridine, dimethylaminoethyl methacrylate, ethyleneimine, guanidine, diallyldimethylammonium chloride, and alkylamine-epichlorohydrin condensates.

[0075] Examples of cationic surfactants include quaternary ammonium salts, quaternary ammonium ions, primary, secondary, and tertiary amine salt compounds, alkylamine salts, dialkylamine salts, aliphatic amine salts, alkylpyridinium salts, imidazolinium salts, sulfonium salts, phosphonium salts, and onium salts. Specific examples of cationic surfactants other than quaternary ammonium salts and quaternary ammonium ions include hydrochloride and acetate salts of laurylamine, coconutamine, rosinamine, etc., as well as cetylpyridinium chloride, cetylpyridinium bromide, and dihydroxyethyl laurylamine.

[0076] Examples of polyvalent metal salts include aluminum chloride, aluminum bromide, aluminum sulfate, aluminum nitrate, aluminum acetate, barium chloride, barium bromide, barium iodide, barium oxide, barium nitrate, barium thiocyanate, calcium chloride, calcium bromide, calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, calcium lactate, calcium fumarate, calcium citrate, copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, and chloride. Examples include iron, iron bromide, iron iodide, iron sulfate, iron nitrate, iron oxalate, iron lactate, iron fumarate, iron citrate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, manganese sulfate, manganese nitrate, manganese dihydrogen phosphate, manganese acetate, manganese salicylate, manganese benzoate, manganese lactate, nickel chloride, nickel bromide, nickel sulfate, nickel nitrate, nickel acetate, tin sulfate, titanium chloride, zinc chloride, zinc bromide, zinc sulfate, zinc nitrate, zinc thiocyanate, zinc acetate, etc.

[0077] The coagulant may be one type from the above list used alone, or two or more types may be used in combination. The amount of coagulant relative to the total amount of pretreatment liquid is not particularly limited. The range of the amount is, for example, 0.50% by mass or more and 20.0% by mass or less, 1.00% by mass or more and 20.0% by mass or less, and 1.00% by mass or more and 15.00% by mass or less.

[0078] The pretreatment solution may further contain additives such as solvents, pH adjusters, and preservatives, as needed.

[0079] (Inkjet recording device) Next, the inkjet recording device 10 of the embodiment will be described with reference to the drawings. Hereinafter, the inkjet recording device 10 may be simply referred to as the recording device 10. The recording device 10 is a device that ejects water-based inkjet recording ink toward a fabric material according to an inkjet recording method and records an image toward the fabric material. In this embodiment, the recording device 10 is a device that performs printing on a fabric material by an inkjet recording method. The recording device 10 is used by being placed on a table. However, in other embodiments, the recording device 10 may be used by being placed on the floor or on a rack.

[0080] As shown in Figure 1, the recording device 10 comprises a storage tank 11, a carriage 12, a discharge head 13, a pair of transport rollers 14, a pair of guide rails 15, a sub-tank 16, and a control unit 20. The control unit 20 is communicatively connected to each part of the recording device 10 and controls the operation of each part. The control unit 20 is also communicatively connected to a pre-treatment liquid coating device 22, which will be described later, and controls the operation of the pre-treatment liquid coating device 22. The fabric material 30, which is the object of image formation, is placed on the platen of the recording device 10.

[0081] A discharge head 13 is mounted on the carriage 12. The carriage 12 is supported by a pair of guide rails 15. The carriage 12 reciprocates along the guide rails 15 in the direction of movement Ds. As a result, the discharge head 13 reciprocates in the direction of movement Ds. The direction of movement Ds is perpendicular to the direction Df of fabric material transport.

[0082] The carriage 12 is equipped with multiple sub-tanks 16. Each sub-tank 16 is connected to a corresponding storage tank 11 via a tube for circulating ink. In Figure 1, the sub-tanks 16 are schematically shown as a single structure.

[0083] A pair of conveyor rollers 14 are arranged parallel to each other along the direction of movement Ds. The conveyor rollers 14 rotate when driven by a conveyor motor, thereby conveying the fabric material 30 on the platen in the conveying direction Df.

[0084] Water-based ink is stored in the storage tank 11. The storage tank 11 is connected to the discharge head 13 via a tube and a sub-tank 16. A separate storage tank 11 is provided for each type of water-based ink. In Figure 1, the storage tank 11 is schematically shown as a single structure, but the recording device 10 may have, for example, five storage tanks 11. The five storage tanks 11 each store water-based ink of white, black, yellow, cyan, and magenta.

[0085] As shown in Figure 2, the carriage 12 is equipped with two discharge heads 13A and 13B. Discharge heads 13A and 13B are aligned along the transport direction Df. When recording an image on the fabric material 30, the carriage 12 is moved along the movement direction Ds. As a result, the discharge heads 13A and 13B move together with the carriage 12. At this time, the discharge heads 13 discharge water-based ink onto the fabric material 30, thereby recording an image on the recording surface of the fabric material 30. In the image recording process, the process of transporting the fabric material 30 in the transport direction Df and the process of moving the discharge heads 13 while discharging water-based ink are repeated alternately.

[0086] The ejection head 13A ejects white ink. The ejection head 13A is provided with a row of nozzles NL for ejecting white ink, arranged along the transport direction Df. In the example shown in Figure 2, the ejection head 13A has four rows of nozzles NL for ejecting white ink, arranged at regular intervals along the movement direction Ds. The number of nozzle rows NL for ejecting white ink is not particularly limited. For example, there may be two rows or one row of nozzles NL for ejecting white ink.

[0087] The ejection head 13B ejects water-based inks of yellow, magenta, cyan, and black. The ejection head 13B is provided with nozzle rows NL for ejecting each water-based ink, along the transport direction Df. Each nozzle row NL is arranged at a constant interval along the movement direction Ds.

[0088] In addition to the five storage tanks 11 for storing each of the aforementioned water-based inks, the recording device 10 may also include a storage tank for storing special color inks. In this case, for example, one of the nozzle rows NL of the discharge head 13A may be used to discharge the special color ink.

[0089] (Image forming method) Next, an image formation method using an inkjet recording method with a recording device 10 will be described. This image formation method comprises a pre-treatment step, a pre-treatment liquid fixing step, an image formation step, and a drying step. The control unit 20 executes each step in response to, for example, a command to form an image being input to the recording device 10 from an external source. When the command is input, the control unit 20 transports the fabric material 30 by controlling various parts such as a pair of transport rollers 14.

[0090] (Pre-treatment process) In the pretreatment step, the control unit 20 applies a pretreatment solution to the recording surface of the cloth material 30. The pretreatment step is performed with the aim of suppressing the bleeding of water-based ink and improving the fixation and color development of pigments. The specific configuration for applying the pretreatment solution to the cloth material 30 is not particularly limited. For example, as shown in Figure 3, the pretreatment solution can be applied to the cloth material 30 using a pretreatment solution application device 22 that is independent of the recording device 10. The control unit 20 controls the operation of the pretreatment solution application device 22 to apply the pretreatment solution to the recording surface of the cloth material 30 as it passes through the pretreatment solution application device 22.

[0091] The method of applying the pretreatment solution to the fabric material 30 is not particularly limited. Examples of pretreatment solution application methods include spray coating, blade coating, roll coating, inkjet, and immersion processing methods. The immersion processing method involves immersing the fabric material 30 in the pretreatment solution and then squeezing the fabric material 30 with a mangle roll. From the viewpoint of continuously performing the application of the pretreatment solution and image formation with water-based ink, an inkjet method may be adopted.

[0092] In the pretreatment step, the pretreatment solution is applied to the image-forming area with water-based ink. The pretreatment solution may be applied to the entire recording surface of the cloth material 30, or to only a portion of the area including the image-forming area. In the former case, a spray coating method, blade coating method, roll coating method, immersion processing method, etc., can be suitably employed. In the latter case, an inkjet method can be suitably employed.

[0093] Furthermore, the recording device 10 itself may also have the function of a pretreatment liquid coating device 22. That is, the recording device 10 may be configured to coat the fabric material 30 with pretreatment liquid. Also, if the pretreatment liquid is coated by an inkjet method, a separate discharge head for coating the pretreatment liquid may be provided on the carriage 12 of the recording device 10.

[0094] (Pretreatment solution fixing process) In the pretreatment solution fixing process, the control unit 20 fixes the pretreatment solution applied to the cloth material 30 to the recording surface of the cloth material 30 by drying it. The control unit 20 fixes the pretreatment solution to the recording surface of the cloth material 30 by controlling the drying device provided in the pretreatment solution application device 22.

[0095] The method for drying the pretreatment solution is not particularly limited. Methods for drying the pretreatment solution include air drying and heating with equipment. Examples of such equipment include commercially available irons, heat presses, dryers, ovens, and belt conveyor ovens.

[0096] (image forming process) In the image forming process, the control unit 20 ejects water-based ink onto the recording surface of the transported fabric material 30. The control unit 20 controls piezoelectric elements, etc., corresponding to each nozzle provided on the carriage 12 and the ejection head 13, to selectively eject water-based ink from each nozzle toward the fabric material 30 passing below the ejection head 13. As a result, a predetermined image is formed on the recording surface of the fabric material 30.

[0097] (drying process) In the drying process, the control unit 20 heats the fabric material 30 coated with water-based ink to dry the water-based ink. The control unit 20 controls, for example, a drying device provided in the recording device 10 to dry the water-based ink adhering to the recording surface of the fabric material 30. As a method for drying the water-based ink, various drying methods described above in the pretreatment liquid fixing process can be employed. In the drying process, by heating and drying the fabric material 30 on which the image has been recorded, the pigment can be fixed more effectively to the fibers constituting the fabric material 30.

[0098] The heating temperature of the fabric material 30 during the drying process is not particularly limited. For example, the heating temperature can be 80°C to 200°C, 100°C to 190°C, 110°C to 185°C, or 130°C to 180°C. The drying time for the same position of the fabric material 30 is not particularly limited, but for example, it can be 120 seconds to 600 seconds.

[0099] In the above-described embodiment, the control unit 20 of the recording device 10 controlled the operation of the pretreatment liquid coating device 22. However, a separate dedicated control unit for controlling the pretreatment liquid coating device 22 may be provided. Furthermore, the pretreatment liquid fixing step does not have to be performed after the pretreatment step, or neither the pretreatment step nor the pretreatment liquid fixing step may be performed. In other words, the image forming method disclosed herein only needs to include at least an image forming step and a drying step. [Examples]

[0100] Next, the aqueous inks disclosed herein will be described in detail with reference to examples and comparative examples. However, the technologies disclosed herein are not limited in any way to these examples.

[0101] (Preparation of the aqueous ink in Example 1) A mixture of 21.50% by mass of glycerin as a wetting agent, 3.00% by mass of triethylene glycol-n-butyl ether as a penetrating agent, 0.25% by mass of BYK-3420 as a surfactant, and 66.35% by mass of water was added. Then, 4.50% by mass of Takelac W-5130 as a binder (based on solid content), 0.90% by mass of Epocross WS-700 as a crosslinking agent (based on solid content), and 0.50% by mass of AQUACER1547 as wax particles were added and mixed. Finally, a black pigment dispersion (based on solid content) was added and mixed as a pigment (based on solid content). The resulting mixture was filtered through a cellulose acetate type membrane filter (pore size 3.00 μm) manufactured by Toyo Roshi Co., Ltd. to obtain the aqueous ink of Example 1.

[0102] (Preparation of aqueous inks for Examples 2-31 and Comparative Examples 1-5) Except for the types and amounts of components listed in Tables 1 to 4, the same procedure as in the preparation of the aqueous ink in Example 1 was followed to obtain the aqueous inks for each example.

[0103] [Table 1]

[0104] [Table 2]

[0105] [Table 3]

[0106] [Table 4]

[0107] In Tables 1 to 4, the black pigment dispersion is an aqueous dispersion of carbon black, and the magenta pigment dispersion is an aqueous dispersion of CI Pigment Red 122. Furthermore, the content of each component in each example represents the solid content or active ingredient content of that component relative to the total amount of aqueous ink.

[0108] (Preparation of evaluation samples) As a pretreatment step, a 350mm x 350mm piece of 100% cotton white woven fabric was coated with 80.00 g / m2 of a calcium nitrate aqueous solution diluted to 0.30% by mass as a pretreatment solution, and dried in an oven set to 120°C for 3 minutes to obtain a pretreated woven fabric. The pretreated woven fabric was set in a Brother Industries, Ltd. GTX® pro garment printer. Using the water-based inks prepared for each example, the amount ejected from the inkjet head was adjusted to 20 pL per pixel, and an image was formed on the pretreated woven fabric by solid printing at a resolution of 1200 dpi x 1200 dpi. After image formation, the pretreated woven fabric was heated in an oven set to 160°C for 5 minutes to obtain an evaluation sample.

[0109] For each example and comparative example, the storage stability, dry friction fastness, wash fastness, and hydrolysis resistance of the ink were evaluated according to the methods described below.

[0110] (Evaluation of ink storage stability) Each prepared aqueous ink sample was placed in a sealed container and stored for one week in a constant temperature bath manufactured by ESPEC Corporation and set to 60°C. The viscosity before and after one week of storage was measured at 25°C using a TVE-25 viscometer manufactured by Toki Sangyo Co., Ltd. The percentage change in viscosity after storage compared to before storage was calculated, and the storage stability of the aqueous ink was evaluated according to the following criteria. The evaluation results are shown in Tables 1 to 4. A: Rate of change is less than 10% B: Change rate of 10% or more

[0111] (Evaluation of dry friction fastness) For each example, the dry rub fastness grade was calculated for the evaluation sample using a test method compliant with ISO 105-X12, and the dry rub fastness of the water-based ink was evaluated according to the following criteria. The evaluation results and dry rub fastness grades are shown in Tables 1 to 4. A: Level 3 or above B: Less than Grade 3

[0112] (Wash fastness of evaluation samples immediately after preparation) Each evaluation sample was placed in a Toshiba AW-304 household washing machine along with a load cloth within 24 hours of sample preparation. 30g of a weakly alkaline synthetic laundry detergent for general household use was added to 45L of water, and the washing cycle was performed. This procedure was repeated five times. After five repetitions, evaluation samples within 72 hours (i.e., immediately after preparation) were compared with the pre-wash evaluation samples, and the degree of color fading was determined using the grayscale for color change specified in JIS L0804. Based on the determination results, the wash fastness grade of the immediately prepared evaluation samples was calculated, and the wash fastness of the water-based ink was evaluated according to the following criteria. The evaluation results and the wash fastness grades of the immediately prepared evaluation samples are shown in Tables 1 to 4. A: Level 4 or higher B: Grade 3 or higher, but less than Grade 4 C: Below Grade 3

[0113] (Hydrolysis resistance) A hydrolysis resistance test was conducted by placing each evaluation sample in a constant temperature chamber manufactured by ESPEC Corporation and set to 70°C and 95% humidity, and leaving it for two weeks. Afterward, the same procedure as in the wash fastness evaluation described above was repeated five times. The evaluation samples after the five repetitions were compared to the evaluation samples before the hydrolysis resistance test, and the degree of color fading was determined using the gray scale for color change specified in JIS L0804. Based on the determination results, the wash fastness grade of the evaluation samples after the hydrolysis resistance test was calculated. Then, the difference between the wash fastness grade of the evaluation sample immediately after preparation and the wash fastness grade of the evaluation sample after the hydrolysis resistance test was calculated, and the hydrolysis resistance of the water-based ink was evaluated according to the following criteria. The evaluation results are shown in Tables 1 to 4. Note that a good evaluation of hydrolysis resistance means that the difference between the wash fastness of the evaluation sample immediately after preparation and the wash fastness of the evaluation sample after the hydrolysis resistance test is small. However, if the wash fastness rating of the evaluation sample immediately after preparation is low, even if the hydrolysis resistance evaluation is good, the wash fastness rating of the evaluation sample after the hydrolysis resistance test will be as low as the wash fastness rating of the sample immediately after preparation, meaning that the wash fastness over a long period of time will also be low. A:±0 class B: Greater than -1 grade and less than ±0 grade C: -1 grade or below

[0114] As shown in Tables 1 to 4, the aqueous inks of Examples 1 to 31 all contain a pigment, a binder, and a crosslinking agent. The binder is a polyurethane resin having a polyester skeleton, and the crosslinking agent is an oxazoline group-containing compound. The ratio of the binder content to the pigment content is 1.40 or higher, and the ratio of the crosslinking agent content to the binder content is 0.15 or higher. The total solid content of the aqueous inks of Examples 1 to 31 is 7.20% by mass or higher. The aqueous inks of Examples 1 to 31 obtained good results, i.e., "A" or "B", for all evaluation items.

[0115] In contrast, in Comparative Examples 1 and 2, the wash fastness of the evaluation samples immediately after preparation was low, i.e., it was rated "C". The binder contained in the aqueous ink of Comparative Example 1 is a polyurethane resin having a polycarbonate skeleton. The functional groups of polyurethane resin having a polycarbonate skeleton have low reactivity with oxazoline groups. Therefore, a suitable cross-linking structure was not formed, resulting in poor fixation to the woven fabric, which is thought to have led to a low wash fastness rating of the evaluation sample immediately after preparation. Similarly, the binder contained in the aqueous ink of Comparative Example 2 is a polyurethane resin having a polyether skeleton. The functional groups of polyurethane resin having a polyether skeleton also have low reactivity with oxazoline groups. Therefore, a suitable cross-linking structure was not formed, resulting in poor fixation to the woven fabric, which is thought to have led to a low wash fastness rating of the evaluation sample immediately after preparation.

[0116] Furthermore, while the aqueous ink of Comparative Example 3 contains the same binder and crosslinking agent as the aqueous ink of the Examples, the ratio of binder content to pigment content is relatively low at 1.17. In other words, compared to the Examples, the binder content is lower relative to the pigment content. As a result, a sufficient resin coating film to fix the pigment to the woven fabric was not formed, and it is thought that the wash fastness evaluation of the evaluation sample immediately after preparation was "C".

[0117] In Comparative Examples 1-3, the hydrolysis resistance rating is "A," which indicates that the difference between the wash fastness of the evaluation samples after the hydrolysis resistance test and the wash fastness of the evaluation samples immediately after preparation is small. Therefore, the wash fastness rating of Comparative Examples 1-3 after the hydrolysis resistance test is as low as the wash fastness immediately after preparation. In other words, in Comparative Examples 1-3, the wash fastness of the evaluation samples is insufficient from the stage immediately after preparation, and high wash fastness over a long period cannot be expected.

[0118] Furthermore, while the aqueous ink of Comparative Example 4 contains the same binder and crosslinking agent as the aqueous ink of the Examples, the ratio of the crosslinking agent content to the binder content is relatively low at 0.12. In other words, compared to the Examples, the crosslinking agent content is lower relative to the binder content. As a result, the binder could not be suitably crosslinked, and in the hydrolysis resistance test, the ester bonds underwent hydrolysis, impairing the fixation of the pigment. Consequently, the hydrolysis resistance evaluation was low, resulting in a "C" rating. In short, Comparative Example 4 failed to maintain high wash fastness over a long period of time.

[0119] Furthermore, the aqueous ink of Comparative Example 5 contains Carbodilite® V-04, a carbodiimide group-containing compound from Nisshinbo Chemical Co., Ltd., as a crosslinking agent. Carbodiimide group-containing compounds, like oxazoline group-containing compounds, can suitably crosslink binders containing polyurethane resins having a polyester skeleton. Therefore, a sufficient resin coating film can be formed to fix the pigment to the woven fabric, and high wash fastness can be obtained immediately after the preparation of the evaluation sample. On the other hand, the resin coating film of Comparative Example 5 has higher hydrophilicity compared to the resin coating films of each example. For this reason, in the hydrolysis resistance test, the ester bonds of the binder are easily hydrolyzed, and it is thought that the wash fastness grade after the hydrolysis resistance test became "C". In other words, Comparative Example 5 also failed to maintain high wash fastness over a long period of time.

[0120] Next, we will compare and examine each example. As shown in Table 1, the aqueous inks of Examples 1 to 5 contain common pigments, crosslinking agents, binders, and wax particles, but their contents vary. Example 4, which has the highest total solids content, has lower storage stability compared to Examples 1 to 3 and 5. It is thought that when the total solids content relative to the total amount of aqueous ink increases, the interaction between resin particles increases, thus reducing storage stability. The storage stability of the aqueous ink of Example 25, which has a total solids content of 12.70% by mass, is "A", while the storage stability of Example 4, which has a total solids content of 13.10% by mass, is "B". Therefore, it is preferable that the total solids content relative to the total amount of aqueous ink is 12.70% by mass or less. On the other hand, even though the total solids content is 12.70% by mass or less, the storage stability of Example 26, where the ratio of crosslinking agent content to binder content exceeds 0.40, is "B". Therefore, it is preferable that the ratio of crosslinking agent content to binder content is 0.40 or less. Furthermore, in all examples where the total solids content is 12.70% by mass or less, the ratio of binder content to pigment content is 2.80 or less. Therefore, a ratio of binder content to pigment content of 2.80 or less is preferable. Overall, it is preferable that the total solids content is 12.70% by mass or less, the ratio of crosslinking agent content to binder content is 0.40 or less, and the ratio of binder content to pigment content is 2.80 or less.

[0121] The aqueous inks of Examples 6 and 7 have the same composition as the aqueous ink of Example 2, except that they contain different binders. The binders contained in the aqueous inks of Examples 2, 6, and 7 are all polyurethane resins with a polyester backbone, but different commercially available products were used in each case. There was almost no difference in the evaluation results in Examples 2, 6, and 7, indicating that aqueous inks containing polyurethane resins with a polyester backbone as a binder yield good results.

[0122] The aqueous ink of Example 8 has the same composition as the aqueous ink of Example 2, except that it contains a different pigment. From the evaluation results of Example 8, it can be seen that good results can be obtained regardless of the pigment by appropriately setting the properties of the crosslinking agent and binder, the ratio of the crosslinking agent content to the binder content, and the ratio of the binder content to the pigment content.

[0123] The aqueous inks of Examples 9-12 have the same composition as the aqueous ink of Example 2, except that the crosslinking agent content differs. As shown in Tables 1 and 2, storage stability may decrease as the ratio of crosslinking agent content to binder content increases. This is thought to be due to the increase in crosslinking agent content. It is thought that when the crosslinking agent content of aqueous inks becomes relatively high, the dispersion system of the aqueous ink tends to become unstable, which can lead to decreased storage stability.

[0124] The aqueous ink of Example 13 has the same composition as the aqueous ink of Example 2, except that it contains a different crosslinking agent. The crosslinking agent contained in the aqueous ink of Example 13 is a water-soluble oxazoline group-containing compound, similar to that in Example 2, but a different commercially available product is used. There is almost no difference in the evaluation results between Example 2 and Example 13. Furthermore, the aqueous ink of Example 14, which differs from Example 13 only in the crosslinking agent content, also obtained good results. From these results, it can be seen that aqueous inks containing a water-soluble oxazoline group-containing compound as a crosslinking agent yield good results.

[0125] The aqueous inks of Examples 15 and 16 have the same composition as the aqueous ink of Example 2, except that they contain different crosslinking agents. The crosslinking agents contained in the aqueous inks of Examples 15 and 16 are oxazoline group-containing compounds, similar to Example 2, but different commercially available products were used in both cases. The crosslinking agents contained in the aqueous inks of Examples 15 and 16 are emulsions, while the crosslinking agent contained in Example 2 is water-soluble. In Examples 15 and 16, the hydrolysis resistance evaluation is "B," which is lower than the evaluation "A" in Example 2. This is thought to be because the water-soluble form of the crosslinking agent allowed for more favorable crosslinking of the binder than the emulsion form. By forming a sufficient crosslinked structure, the binder becomes more molecular weight and its hydrophobicity improves. In Example 2, the ester bonds of the binder were less susceptible to hydrolysis in the hydrolysis resistance test, resulting in good hydrolysis resistance.

[0126] The wetting agent contained in the aqueous inks of Examples 17-22 is polyethylene glycol. Polyethylene glycol has high compatibility with the binder in aqueous ink and improves the fixation of the pigment. For this reason, it is thought that the wash fastness of the evaluation samples immediately after preparation in Examples 17-22 was high, resulting in a rating of "B" or "A". In particular, in Examples 18-22, which contained polyethylene glycol with a degree of polymerization of 4 or higher so that the ratio of polyethylene glycol with a degree of polymerization of 4 or higher to the total wetting agent content was 0.40 or higher, the wash fastness of the evaluation samples immediately after preparation was especially high, resulting in a rating of "A". Examples of polyethylene glycol with a degree of polymerization of 4 or higher include tetraethylene glycol, pentaethylene glycol, and hexaethylene glycol. This is thought to be because polyethylene glycol with a relatively high degree of polymerization has a high boiling point and is not easily volatile, so it remains on the woven fabric for a longer time during the drying process, and by being in contact with the binder for a longer time, a suitable resin coating film covering the pigment is formed. In all of the aqueous inks of Examples 18 to 22, the ratio of wax particle content to binder content is 0.04 or higher, the total solid content relative to the total amount of aqueous ink is 12.70% by mass or less, the ratio of crosslinking agent content to binder content is 0.40 or less, the ratio of binder content to pigment content is 2.80 or less, the crosslinking agent is water-soluble, and further contains a wetting agent, the wetting agent contains polyethylene glycol with a degree of polymerization of 4 or higher, and the ratio of polyethylene glycol content to wetting agent content is 0.40 or higher.

[0127] The aqueous inks of Examples 23 to 26 have the same composition as the aqueous ink of Example 2, except that the wax particle content differs. Example 23, which does not contain wax particles, has a lower dry abrasion fastness rating of "B" compared to the other examples. The aqueous inks of the other examples all contain 0.25% by mass or more of wax particles and have a dry abrasion fastness rating of "A". In the aqueous inks of the other examples, the ratio of wax particle content to binder content is 0.04 or more. From these results, it can be seen that aqueous inks containing 0.25% by mass or more of wax particles have higher abrasion resistance of the resin coating film than aqueous inks that do not contain wax particles. Furthermore, Example 26 has a lower storage stability rating of "B" compared to the other examples. This is thought to be due to the increase in total solid content, as mentioned above.

[0128] The aqueous inks of Examples 27 and 28 have the same composition as the aqueous ink of Example 3, except that they contain different wax particles. The wax particles contained in the aqueous ink of Example 3 are polyethylene wax AQUACER 1547. The wax particles contained in the aqueous ink of Example 27 are polyethylene wax AQUACER 531. The wax particles contained in the aqueous ink of Example 28 are paraffin wax AQUACER 537. There was almost no difference in the evaluation results in Examples 3, 27, and 28, indicating that good results can be obtained by including wax particles, regardless of the type of wax particle. The melting points of the wax particles used in these examples are all 100°C or higher. Therefore, it is thought that better results can be obtained by including wax particles with a melting point of 100°C or higher.

[0129] The aqueous ink of Example 29 has the same composition as the aqueous ink of Example 27, except that it contains a different surfactant. The aqueous ink of Example 30 has the same composition as the aqueous ink of Example 3, except that it contains a different surfactant. Both the aqueous inks of Examples 29 and 30 contain the surfactant BYK-3456. Comparing Example 27 and Example 29, there is almost no difference in the evaluation results. Similarly, comparing Example 3 and Example 30, there is almost no difference in the evaluation results. These results indicate that good results can be obtained regardless of the type of surfactant.

[0130] The aqueous ink of Example 31 differs from the aqueous ink of Example 29 in that it contains tetraethylene glycol, which is polyethylene glycol with a degree of polymerization of 4, as a wetting agent. As a result, the wash fastness of the evaluation sample immediately after preparation in Example 31 was particularly high, rated as "A".

[0131] From the above results, it was found that an aqueous ink containing a polyurethane resin with a polyester skeleton as a binder and an oxazoline group-containing compound as a crosslinking agent maintains good wash fastness over a long period of time by appropriately setting the ratio of binder content to crosslinking agent content and the ratio of binder content to pigment content.

[0132] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above.

[0133] Furthermore, the technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness.

[0134] Even if, in the claims of this patent application, each claim depends on only some of the claims, it is not limited to the claim being dependent only on those specific claims. To the extent that it is not technically contradictory, each claim may be dependent on other claims that were not dependent at the time of application. That is, the technologies of each claim can be combined in various ways as follows: (Item 1) An inkjet water-based ink used to form an image on a fabric material, Pigments and Binder and, Crosslinking agent and Equipped with, The binder comprises a polyurethane resin having a polyester skeleton. The crosslinking agent comprises an oxazoline group-containing compound, The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the content of the crosslinking agent to the content of the binder is 0.15 or more. Water-based ink for inkjet recording. (Item 2) A water-based inkjet recording ink, as described in item 1, further containing wax particles. (Item 3) The water-based inkjet recording ink according to item 2, wherein the content of the wax particles relative to the total amount of the water-based inkjet recording ink is 0.25% by mass or more. (Item 4) The water-based inkjet recording ink according to item 2 or 3, wherein the ratio of the content of wax particles to the content of the binder is 0.04 or more. (Item 5) An inkjet water-based ink for recording according to any one of items 2 to 4, wherein the melting point of the wax particles is 100°C or higher. (Item 6) The water-based inkjet recording ink according to any one of items 1 to 5, wherein the total solid content relative to the total amount of the aforementioned water-based inkjet recording ink is 12.70% by mass or less. (Item 7) An inkjet water-based ink for recording according to any one of items 1 to 6, wherein the ratio of the content of the crosslinking agent to the content of the binder is 0.40 or less. (Item 8) An inkjet water-based ink for recording according to any one of items 1 to 7, wherein the ratio of the binder content to the pigment content is 2.80 or less. (Item 9) The water-based inkjet recording ink according to any one of items 1 to 8, wherein the total solid content relative to the total amount of the aforementioned water-based inkjet recording ink is 7.20% by mass or more. (Item 10) The total solid content relative to the total amount of the aforementioned water-based inkjet recording ink is 12.70% by mass or less. The ratio of the content of the crosslinking agent to the content of the binder is 0.40 or less. The ratio of the binder content to the pigment content is 2.80 or less. Water-based inkjet recording ink as described in item 1. (Item 11) The crosslinking agent is water-soluble, and the inkjet recording water-based ink is one of the items 1 to 10. (Item 12) It further contains a humectant, The aforementioned wetting agent is an aqueous inkjet recording ink according to any one of items 1 to 11, comprising polyethylene glycol. (Item 13) The polyethylene glycol is an aqueous inkjet recording ink as described in item 12, wherein the degree of polymerization is 4 or higher. (Item 14) The water-based inkjet recording ink according to item 12 or 13, wherein the ratio of the polyethylene glycol content to the wetting agent content is 0.40 or more. (Item 15) The ratio of the content of the wax particles to the content of the binder is 0.04 or more. The total solid content relative to the total amount of the aforementioned water-based inkjet recording ink is 12.70% by mass or less. The ratio of the content of the crosslinking agent to the content of the binder is 0.40 or less. The ratio of the binder content to the pigment content is 2.80 or less. The aforementioned crosslinking agent is water-soluble, The aforementioned water-based inkjet recording ink further contains a wetting agent, The aforementioned wetting agent contains polyethylene glycol having a degree of polymerization of 4 or more. The ratio of the polyethylene glycol content to the wetting agent content is 0.40 or more. Water-based inkjet recording ink as described in item 2. (Item 16) A water-based inkjet recording ink described in any of items 1 through 15, A pretreatment liquid applied to the fabric material before forming an image on the fabric material using the aforementioned water-based inkjet recording ink, An ink set equipped with this feature. (Item 17) An inkjet recording apparatus comprising an ink storage section, an ink ejection section, and an aqueous inkjet recording ink stored in the ink storage section, wherein the aqueous inkjet recording ink is ejected from the ink ejection section to form an image on a fabric material, The aforementioned water-based inkjet recording ink is Pigments and Binder and, Crosslinking agent and Equipped with, The binder comprises a polyurethane resin having a polyester skeleton. The crosslinking agent comprises an oxazoline group-containing compound, The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the content of the crosslinking agent to the content of the binder is 0.15 or more. Inkjet recording device. (Item 18) An image forming method for forming an image on a fabric material using an inkjet recording method, An image forming step of forming an image on the fabric material using the water-based inkjet recording ink, A drying step in which the water-based inkjet recording ink is dried by heating the fabric material on which the image has been formed, Equipped with, The aforementioned water-based ink for inkjet recording comprises a pigment, a binder, and a crosslinking agent, wherein the binder includes a polyurethane resin having a polyester backbone. The crosslinking agent comprises an oxazoline group-containing compound, The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the content of the crosslinking agent to the content of the binder is 0.15 or more. Image forming method. (Item 19) The image forming method according to item 18, further comprising a pretreatment step of applying a pretreatment liquid to the fabric material before the image forming step, wherein the pretreatment liquid is applied to an area where an image is formed by the water-based inkjet recording ink. [Explanation of Symbols]

[0135] 10: Inkjet recording device, 11: Storage tank, 12: Carriage, 13: Discharge head, 14: Conveyor roller, 15: Guide rail, 16: Sub-tank, 20: Control unit, 22: Pretreatment liquid coating device, 30: Fabric material

Claims

1. An inkjet water-based ink used to form an image on a fabric material, Pigments and Binder and, Crosslinking agent and Equipped with, The binder comprises a polyurethane resin having a polyester skeleton. The crosslinking agent comprises an oxazoline group-containing compound, The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the content of the crosslinking agent to the content of the binder is 0.15 or more. Water-based ink for inkjet recording.

2. The aqueous inkjet recording ink according to claim 1, further comprising wax particles.

3. The water-based inkjet recording ink according to claim 2, wherein the content of the wax particles relative to the total amount of the water-based inkjet recording ink is 0.25% by mass or more.

4. The water-based inkjet recording ink according to claim 2, wherein the ratio of the content of wax particles to the content of the binder is 0.04 or more.

5. The aqueous inkjet recording ink according to claim 4, wherein the melting point of the wax particles is 100°C or higher.

6. The water-based inkjet recording ink according to claim 1, wherein the total solid content relative to the total amount of the water-based inkjet recording ink is 12.70% by mass or less.

7. The aqueous inkjet recording ink according to claim 1, wherein the ratio of the content of the crosslinking agent to the content of the binder is 0.40 or less.

8. The water-based inkjet recording ink according to claim 1, wherein the ratio of the binder content to the pigment content is 2.80 or less.

9. The water-based inkjet recording ink according to claim 6, wherein the total solid content relative to the total amount of the water-based inkjet recording ink is 7.20% by mass or more.

10. The total solid content relative to the total amount of the aforementioned water-based inkjet recording ink is 12.70% by mass or less. The ratio of the content of the crosslinking agent to the content of the binder is 0.40 or less. The ratio of the binder content to the pigment content is 2.80 or less. The aqueous ink for inkjet recording according to claim 1.

11. The water-soluble inkjet recording ink according to claim 1, wherein the crosslinking agent is water-soluble.

12. It further contains a humectant, The aqueous inkjet recording ink according to claim 1, wherein the wetting agent comprises polyethylene glycol.

13. The aqueous inkjet recording ink according to claim 12, wherein the polyethylene glycol has a degree of polymerization of 4 or more.

14. The aqueous inkjet recording ink according to claim 13, wherein the ratio of the content of polyethylene glycol to the content of the wetting agent is 0.40 or more.

15. The ratio of the content of the wax particles to the content of the binder is 0.04 or more. The total solid content relative to the total amount of the aforementioned water-based inkjet recording ink is 12.70% by mass or less. The ratio of the content of the crosslinking agent to the content of the binder is 0.40 or less. The ratio of the binder content to the pigment content is 2.80 or less. The aforementioned crosslinking agent is water-soluble, The aforementioned water-based inkjet recording ink further contains a wetting agent, The aforementioned wetting agent contains polyethylene glycol having a degree of polymerization of 4 or more. The ratio of the polyethylene glycol content to the wetting agent content is 0.40 or more. The aqueous ink for inkjet recording according to claim 2.

16. An aqueous inkjet recording ink according to any one of claims 1 to 15, A pretreatment liquid applied to the fabric material before forming an image on the fabric material using the aforementioned water-based inkjet recording ink, An ink set equipped with this feature.

17. An inkjet recording apparatus comprising an ink storage section, an ink ejection section, and an aqueous inkjet recording ink stored in the ink storage section, wherein the aqueous inkjet recording ink is ejected from the ink ejection section to form an image on a fabric material, The aforementioned water-based inkjet recording ink is Pigments and Binder and, Crosslinking agent and Equipped with, The binder comprises a polyurethane resin having a polyester skeleton. The crosslinking agent comprises an oxazoline group-containing compound, The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the content of the crosslinking agent to the content of the binder is 0.15 or more. Inkjet recording device.

18. An image forming method for forming an image on a fabric material using an inkjet recording method, An image forming step in which an image is formed on the fabric material using the water-based inkjet recording ink, A drying step in which the water-based ink for inkjet recording is dried by heating the fabric material on which the image has been formed, Equipped with, The aforementioned water-based inkjet recording ink comprises a pigment, a binder, a crosslinking agent, Equipped with, The binder comprises a polyurethane resin having a polyester skeleton. The crosslinking agent comprises an oxazoline group-containing compound, The ratio of the binder content to the pigment content is 1.40 or more. The ratio of the content of the crosslinking agent to the content of the binder is 0.15 or more. Image forming method.

19. The image forming method according to claim 18, further comprising a pretreatment step of applying a pretreatment liquid to the fabric material before the image forming step, wherein the pretreatment liquid is applied to an area in which an image is formed by the water-based inkjet recording ink.

Images