Ink set and inkjet printing recording method

Abstract

This provides an ink set that produces images with good friction fastness. [Solution] An ink set comprising a clear ink which is a textile inkjet composition and a white ink which is a textile inkjet composition, wherein the clear ink contains first resin particles, a crosslinking agent and water, the content of the first resin particles is 4.5% by mass or more relative to the total amount of the clear ink, and the white ink contains a white pigment, second resin particles and water, and the surface tension of the clear ink is 4.5 (mN / m) or more greater than the surface tension of the white ink.

Description

Technical Field

[0001] The present invention relates to an ink set and an inkjet printing method.

Background Art

[0002] The inkjet method has been tried not only for recording images on paper and the like but also for printing on fabrics, and various inkjet printing methods have been studied. Inkjet inks for printing contain coloring materials to obtain images of desired colors, and dyes and pigments are used as coloring materials. Also, many studies have been conducted on inks and recording methods in inkjet printing.

[0003] For example, Patent Document 1 discloses an overcoat liquid for inkjet printing, and describes that high ejection reliability and fastness can be obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In pigment printing, higher rubbing fastness (especially dry rubbing fastness (suppression of peeling of the ink layer during rubbing)) is required for white ink. However, although white ink may contain a relatively large amount of pigment to obtain sufficient color development, it has been difficult in some cases to increase the content of solid components such as resins to ensure rubbing fastness in terms of ejection stability.

Means for Solving the Problems

[0006] One aspect of the ink set according to the present invention is An ink set comprising a clear ink which is a textile inkjet composition and a white ink which is a textile inkjet composition, The clear ink contains first resin particles, a crosslinking agent, and water. The content of the first resin particles is 4.5% by mass or more relative to the total amount of the clear ink. The aforementioned white ink contains a white pigment, second resin particles, and water. The surface tension of the clear ink is at least 4.5 mN / m greater than the surface tension of the white ink.

[0007] One embodiment of the inkjet printing recording method according to the present invention is: An inkjet printing recording method using a clear ink, which is a textile printing inkjet composition, and a white ink, which is a textile printing inkjet composition, The clear ink is ejected by an inkjet method and attached to the fabric in a clear ink application process, The process includes a step of applying white ink, in which the white ink is ejected by an inkjet method and adhered to the fabric. The clear ink contains first resin particles, a crosslinking agent, and water. The content of the first resin particles is 4.5% by mass or more relative to the total amount of the clear ink. The aforementioned white ink contains a white pigment, second resin particles, and water. The surface tension of the clear ink is 4.5 mN / m or more greater than the surface tension of the white ink. The clear ink application step and the white ink application step are performed simultaneously on the same area of ​​the fabric, or the clear ink application step is performed first. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram of an inkjet recording apparatus applicable to the inkjet printing recording method according to this embodiment. [Figure 2] A schematic diagram of an example of an inkjet head in an inkjet recording device. [Figure 3] Table 1 showing the compositions of the white inks used in the examples and comparative examples. [Figure 4] Table 2 showing the compositions of the clear inks used in the examples and comparative examples. [Figure 5] Table 3 showing the compositions of the clear inks used in the examples and comparative examples. [Figure 6] Table 4 showing the conditions and evaluation results of the examples and comparative examples.

Mode for Carrying Out the Invention

[0009] Embodiments of the present invention will be described below. The embodiments described below illustrate examples of the present invention. The present invention is not limited to the following embodiments, and also includes various modified forms implemented within the scope of not changing the gist of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

[0010] In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0011] In this specification, the "inkjet method" refers to a droplet ejection method by an inkjet system.

[0012] In this specification, the term "white" when referring to a white pigment, white ink, etc. does not refer only to a complete white, but includes colors slightly colored with a chromatic or achromatic color or colors with a gloss within the range that can be visually recognized as white. For example, in CIELAB, L * is preferably 80 or more, and L * is more preferably 85 or more.

[0013] In this specification, "(meth)acryl" represents acrylic or methacrylic.

[0014] 1. Ink set The ink set according to this embodiment is an ink set including a clear ink which is a resist inkjet composition and a white ink which is a resist inkjet composition. The ink set may be any one that is used as a set during recording, and is not limited to the case where it is manufactured, sold, etc. in an integrated state. For example, even if it is independently manufactured, sold, etc., if it is premised on being used in combination, or if it substantially induces being used in combination, it is included in the ink set.

[0015] 1.1. Clear Ink The clear ink of this embodiment contains first resin particles, a crosslinking agent, and water.

[0016] 1.1.1. First Resin Particles The clear ink contains first resin particles. The content of the first resin particles in the clear ink is 4.5% by mass or more based on the total amount of the clear ink.

[0017] The first resin particles can improve the fastness, adhesion, etc. of an image formed by the white ink adhered to the fabric. Examples of the first resin particles include urethane resins, acrylic resins (including styrene-acrylic resins), fluorene resins, polyolefin resins, rosin-modified resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate resins, silicone-acrylic resins, etc. Among them, urethane resins, silicone-acrylic resins, acrylic resins, polyolefin resins, and polyester resins are preferable. These resin particles are often handled in emulsion form, but may also be in powder form. Further, the resin particles can be used alone or in combination of two or more.

[0018] Urethane resins are a general term for resins that contain urethane bonds. In addition to urethane bonds, urethane resins may also use polyether-type urethane resins containing ether bonds in the main chain, polyester-type urethane resins containing ester bonds in the main chain, polycarbonate-type urethane resins containing carbonate bonds in the main chain, etc. Furthermore, commercially available urethane resins may be used, such as Superflex 460, 460s, 840, E-4000 (product name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Rezamin D-1060, D-2020, D-4080, D-4200, D-6300, D-6455 (product name, manufactured by Dainichi Seika Kogyo Co., Ltd.), Takelac WS-6021, W-512-A-6 (product name, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), Sankyuar 2710 (product name, manufactured by Lubrizol), Permarin UA-150 (product name, manufactured by Sanyo Chemical Industries, Ltd.), and ETERNACOLL UW series, such as UW-1527 (manufactured by Ube Industries, Ltd.).

[0019] Acrylic resins are a general term for polymers obtained by polymerizing at least one acrylic monomer, such as (meth)acrylic acid or (meth)acrylic acid ester. Examples include resins obtained from acrylic monomers and copolymers of acrylic monomers with other monomers. For example, acrylic-vinyl resins, which are copolymers of acrylic monomers and vinyl monomers, are examples. Examples of vinyl monomers include styrene.

[0020] Acrylic monomers such as acrylamide and acrylonitrile can also be used. For resin emulsions made from acrylic resins, commercially available products may be used, for example, selected from FK-854 (trade name, manufactured by Chuo Rika Kogyo Co., Ltd.), Movinyl 952B, 718A, 6760 (trade name, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Nipol LX852, LX874 (trade name, manufactured by Nippon Zeon Co., Ltd.).

[0021] In this specification, acrylic resin may also refer to styrene-acrylic resin. Furthermore, in this specification, (meth)acrylic means at least one of acrylic and methacrylic.

[0022] Styrene-acrylic resins are copolymers obtained from styrene monomers and (meth)acrylic monomers, and examples include styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, styrene-α-methylstyrene-acrylic acid copolymers, and styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymers. For the styrene-acrylic resin, commercially available products may be used, such as Joncryl 62J, 7100, 390, 711, 511, 7001, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (product names, manufactured by BASF), Movinyl 966A, 975N (product names, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Vinibran 2586 (manufactured by Nisshin Chemical Industry Co., Ltd.), etc.

[0023] Commercially available silicone-acrylic copolymer resins can be used. For example, Nisshin Chemical Industry's Charine series FE-230N, FE-502, E-370, RU-911, R-170, R170S, LC-190, R-170BX, and Toagosei Co., Ltd.'s Cymac US-380. Examples include Cymac US-450, Cymac US-480, Toray Dow Corning Co., Ltd.'s IE-7170, SE1980CLEAR, BY22-826EX, Propylene Oxy LON-MF-40, SABIC Innovative Plastics Japan LLC's Lexan EXL, Idemitsu Kosan Co., Ltd.'s Toughlon Neo, Saiden Chemical Co., Ltd.'s Vansta-S-806, Nippon Synthetic Co., Ltd.'s Movinyl, Toray Industries, Inc.'s Cotax, Ltd., Daito Chemical Industries, Ltd.'s Daitozol 5000SJ, Nippon NSC Co., Ltd.'s Yodozol GH41, Shin-Etsu Chemical Co., Ltd.'s Acrylates / Ethylhexyl Acrylate / Dimethicone Methacrylate Copolymer (product name: KP578), DIC Corporation's Boncoat, Ceranate, and JSR's acrylic silicone emulsions "SIFCLEAR S101" and "SIFCLEAR S102".

[0024] Polyolefin resins have olefins such as ethylene, propylene, and butylene as their structural framework, and known types can be appropriately selected and used. Commercially available olefin resins can be used, for example, Arrowbase CB-1200, CD-1200 (trade names, manufactured by Unitika Ltd.).

[0025] Furthermore, the resin particles may be supplied in the form of an emulsion. Examples of commercially available resin emulsions include Microgel E-1002, E-5002 (product names of Nippon Paint Co., Ltd., styrene-acrylic resin emulsion), Boncoat 4001 (product name of DIC Corporation, acrylic resin emulsion), Boncoat 5454 (product name of DIC Corporation, styrene-acrylic resin emulsion), Polysol AM-710, AM-920, AM-2300, AP-4735, AT-860, and PSASE-4210E (acrylic resin emulsion). ), Polyzol AP-7020 (styrene-acrylic resin emulsion), Polyzol SH-502 (vinyl acetate resin emulsion), Polyzol AD-13, AD-2, AD-10, AD-96, AD-17, AD-70 (ethylene-vinyl acetate resin emulsion), Polyzol PSASE-6010 (ethylene-vinyl acetate resin emulsion) (product name manufactured by Showa Denko Co., Ltd.), Polyzol SAE1014 (product name, styrene-acrylic resin emulsion, manufactured by Nippon Zeon Co., Ltd.), Saibinol SK-200 (product name, acrylic resin emulsion, sa (Manufactured by Iden Chemical Co., Ltd.), AE-120A (product name of JSR Corporation, acrylic resin emulsion), AE373D (product name of E-Tech Co., Ltd., carboxy-modified styrene-acrylic resin emulsion), Seikadine 1900W (product name of Dainichi Seika Kogyo Co., Ltd., ethylene-vinyl acetate resin emulsion), Vinibran 2682 (acrylic resin emulsion), Vinibran 2886 (vinyl acetate-acrylic resin emulsion), Vinibran 5202 (acrylic acetate resin emulsion) (product name of Nisshin Chemical Industry Co., Ltd.), Elitel KA-5071S, KT-8803, KT -9204, KT-8701, KT-8904, KT-0507 (Unitika Corporation product names, polyester resin emulsion), Hi-Tec SN-2002 (Toho Chemical Co., Ltd. product name, polyester resin emulsion), Takelac W-6020, W-635, W-6061, W-605, W-635, W-6021, WS-5100 (Mitsui Chemicals Polyurethane Co., Ltd. product name, urethane resin emulsion), Superflex 870, 800, 150, 420, 460, 470, 610, 700 (Daiichi Kogyo Seiyaku Co., Ltd. product names, urethane resin emulsion),Permarin UA-150 (manufactured by Sanyo Chemical Industries, Ltd., urethane resin emulsion), SunCure 2710 (manufactured by Lubrizol Nippon, urethane resin emulsion), NeoRez R-9660, R-9637, R-940 (manufactured by Kusumoto Chemical Co., Ltd., urethane resin emulsion), Adekabon Titer HUX-380, 290K (manufactured by ADEKA Corporation, urethane resin emulsion), Movinyl 966A, Movinyl 7320 (manufactured by Nippon Synthetic Chemical Co., Ltd.), Joncryl 7100, 390, 711, 511, 7001, 632, 741, 450, 840, 74J, HRC-1645J, 734, 852, 7600, 775, 537J, 1535, PDX-7 You may also select and use from among 630A, 352J, 352D, PDX-7145, 538J, 7640, 7641, 631, 790, 780, 7610 (all manufactured by BASF), NK Binder R-5HN (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), Hydran WLS-210 (non-crosslinked polyurethane: manufactured by DIC Corporation), Joncryl 7610 (manufactured by BASF), etc.

[0026] The acid value of the resin contained in the resin particles is not particularly limited, but is preferably 1 to 300 KOH mg / g, more preferably 10 to 200 KOH mg / g, and even more preferably 20 to 100 KOH mg / g. When the acid value of the resin is within the above range, the resin particles tend to be made anionic and their dispersibility is more easily improved.

[0027] The content of the first resin particles in the clear ink is 4.5% by mass or more relative to the total amount of the clear ink, but is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 9% by mass or more. The upper limit of the content of the first resin particles in the clear ink is not particularly limited, but is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0028] The 100% modulus of the first resin particle may be 10 MPa or higher.

[0029] The 100% modulus of the first resin particles is preferably 5 to 25 MPa, more preferably 10 to 20 MPa, and even more preferably 5 to 20 MPa. When the 100% modulus of the resin particles is 10 MPa or higher, the first resin particles contained in the clear ink become harder, which can improve the frictional fastness of the resulting image.

[0030] As the 100% modulus of the resin particles, a tensile test is performed by heating the resin particles at 170°C for 5 minutes to create a film with a thickness of approximately 60 μm. The value obtained by measuring the tensile stress when the film has stretched to 100% of its original length is adopted in a tensile test conducted under conditions of a tensile test gauge length of 20 mm and a tensile speed of 100 mm / min.

[0031] 1.1.2. Crosslinking Agents The clear ink of this embodiment contains a crosslinking agent. Examples of crosslinking agents include isocyanate-based crosslinking agents, oxazoline-based crosslinking agents, and carbodiimide-based crosslinking agents. These crosslinking agents can be used individually or in combination of two or more.

[0032] Examples of isocyanate-based crosslinking agents include compounds having two or more isocyanate groups in one molecule. Specific examples of isocyanate-based crosslinking agents include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic aliphatic polyisocyanates, aromatic polyisocyanates, and their derivatives. Commercially available products may also be used, such as "Takenate WB-3936" and "WB-3021" from Mitsui Chemicals, Inc.

[0033] Examples of oxazoline-based crosslinking agents include polymers obtained by homopolymerization of oxazoline group-containing ethylenically unsaturated monomers such as 2-isopropenyl-2-oxazoline and 2-vinyl-2-oxazoline, or by copolymerization with other unsaturated monomers. Commercially available oxazoline-based crosslinking agents may also be used, such as "Epocross WS500" and "Epocross K201E" from Nippon Shokubai Co., Ltd.

[0034] Examples of carbodiimide crosslinking agents include compounds containing two or more carbodiimide groups in one molecule. Commercially available carbodiimide crosslinking agents may also be used, such as "Carbodilite V-02" from Nisshinbo Inc.

[0035] The crosslinking agent content is preferably 2 to 10% by mass, more preferably 3 to 7% by mass, and even more preferably 3 to 5% by mass, based on solid content relative to the total amount of clear ink. Furthermore, the ratio of the crosslinking agent content to the solid content of the resin is preferably 0.3 to 0.7, and more preferably 0.3 to 0.5. When the crosslinking agent content is within this range, the clear ink tends to have improved wet friction fastness. However, since the clear ink of this embodiment can also improve friction fastness without containing a crosslinking agent, it is also preferable to omit the crosslinking agent from the viewpoint of improving head reliability and storage stability.

[0036] Alternatively, a blocked isocyanate compound may be selected as the crosslinking agent. A blocked isocyanate compound is a chemically protected isocyanate that contains latent isocyanate groups in which the isocyanate groups are protected by the blocking agent.

[0037] Blocked isocyanate compounds can be obtained, for example, by reacting a polyisocyanate compound with a blocking agent. The inclusion of such blocked isocyanates inhibits crosslinking during storage of the ink composition. After printing, heating deprotects and re-crosslinks the ink, resulting in excellent friction fastness. The isocyanate groups protected by the protecting group are deprotected and activated upon heat, forming chemical bonds such as urethane bonds, urea bonds, allophanate bonds, burette bonds, and isocyanurate bonds.

[0038] The polyisocyanate compounds used in the production of blocked isocyanate compounds are not particularly limited, but examples include polyisocyanate monomers and polyisocyanate derivatives.

[0039] The polyisocyanate monomer is not particularly limited, but examples include polyisocyanates having an aromatic ring, aliphatic polyisocyanates, and alicyclic polyisocyanates. These polyisocyanate monomers may be used individually or in combination of two or more types.

[0040] Polyisocyanates having an aromatic ring are not particularly limited, but examples include tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate. Aliphatic polyisocyanates are not particularly limited, but examples include hexamethylene diisocyanate. Alicyclic polyisocyanates are not particularly limited, but examples include hydrogenated xylylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

[0041] Examples of polyisocyanate derivatives include polymers of the polyisocyanate monomers mentioned above (e.g., dimers, trimers (e.g., isocyanurate modified, iminooxadiazinedione modified), pentamers, heptamers, etc.), allophanate modified forms (e.g., allophanate modified forms produced by the reaction of the polyisocyanate monomers mentioned above with low molecular weight polyols described later), polyol modified forms (e.g., polyol modified forms (alcohol adducts) produced by the reaction of polyisocyanate monomers with low molecular weight polyols described later), biuret modified forms (e.g., Examples include biuret-modified compounds (e.g., those produced by the reaction of the above-mentioned polyisocyanate monomer with water or amines), urea-modified compounds (e.g., urea-modified compounds produced by the reaction of the above-mentioned polyisocyanate monomer with diamines), oxadiazinetrione-modified compounds (e.g., oxadiazinetriones produced by the reaction of the above-mentioned polyisocyanate monomer with carbon dioxide), carbodiimide-modified compounds (e.g., carbodiimide-modified compounds produced by the decarboxylation condensation reaction of the above-mentioned polyisocyanate monomer), uretdione-modified compounds, and uretonimine-modified compounds.

[0042] Furthermore, when using two or more polyisocyanate compounds in combination, for example, during the production of the blocked isocyanate compound, the two or more polyisocyanate compounds may be reacted simultaneously, or the blocked isocyanates obtained using each polyisocyanate compound individually may be mixed.

[0043] Blocking agents inactivate isocyanate groups by blocking them, while regenerating or activating them by deblocking. Blocking agents are not particularly limited, but examples include imidazole compounds, imidazoline compounds, pyrimidine compounds, guanidine compounds, alcohol compounds, phenolic compounds, activated methylene compounds, amine compounds, imine compounds, oxime compounds, carbamic acid compounds, urea compounds, acid amide (lactam) compounds, acid imide compounds, triazole compounds, pyrazole compounds, mercaptan compounds, bisulfites, benzoxazolone, isopropyl anhydride, and tetrabutylphosphonium acetate.

[0044] Examples of imidazole compounds include imidazole (dissociation temperature 100°C), benzimidazole (dissociation temperature 120°C), 2-methylimidazole (dissociation temperature 70°C), 4-methylimidazole (dissociation temperature 100°C), 2-ethylimidazole (dissociation temperature 70°C), 2-isopropylimidazole, 2,4-dimethylimidazole, and 2-ethyl-4-methylimidazole.

[0045] Imidazolin compounds are not particularly limited, but examples include 2-methylimidazoline (dissociation temperature 110°C) and 2-phenylimidazoline.

[0046] The pyrimidine compounds are not particularly limited, but examples include 2-methyl-1,4,5,6-tetrahydropyrimidine.

[0047] Guanidine compounds are not particularly limited, but examples include guanidine, 3,3-dialkylguanidines such as 3,3-dimethylguanidine, 1,1,3,3-tetraalkylguanidines such as 1,1,3,3-tetramethylguanidine (dissociation temperature 120°C), and 1,5,7-triazabicyclo[4.4.0]deca-5-ene.

[0048] The alcohol compounds are not particularly limited, but examples include methanol, ethanol, 2-propanol, n-butanol, s-butanol, 2-ethylhexyl alcohol, 1- or 2-octanol, cyclohexyl alcohol, ethylene glycol, benzyl alcohol, 2,2,2-trifluoroethanol, 2,2,2-trichloroethanol, 2-(hydroxymethyl)furan, 2-methoxyethanol, and methoxypropanol. Examples include 2-ethoxyethanol, n-propoxyethanol, 2-butoxyethanol, 2-ethoxyethoxyethanol, 2-ethoxybutoxyethanol, butoxyethoxyethanol, 2-butoxyethylethanol, 2-butoxyethoxyethanol, N,N-dibutyl-2-hydroxyacetamide, N-hydroxysuccinimide, N-morpholineethanol, 2,2-dimethyl-1,3-dioxolane-4-methanol, 3-oxazolidineethanol, 2-hydroxymethylpyridine (dissociation temperature 140°C), furfuryl alcohol, 12-hydroxystearic acid, triphenylsilanol, and 2-hydroxyethyl methacrylate.

[0049] The phenolic compounds are not particularly limited, but examples include phenol, cresol, ethylphenol, n-propylphenol, isopropylphenol, n-butylphenol, sec-butylphenol, tert-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, n-nonylphenol, di-n-propylphenol, diisopropylphenol, isopropyl cresol, di-n-butylphenol, di-sec-butylphenol, di-tert-butylphenol, di-n-octylphenol, di-2-ethylhexylphenol, Examples include di-n-nonylphenol, nitrophenol, bromophenol, chlorophenol, fluorophenol, dimethylphenol, styrene-phenol, methyl salicylate, methyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 2-ethylhexyl hydroxybenzoate, 4-[(dimethylamino)methyl]phenol, 4-[(dimethylamino)methyl]nonylphenol, bis(4-hydroxyphenyl)acetic acid, 2-hydroxypyridine (dissociation temperature 80°C), 2- or 8-hydroxyquinoline, 2-chloro-3-pyridinol, and pyridine-2-thiol (dissociation temperature 70°C).

[0050] Active methylene compounds are not particularly limited, but examples include meldramic acid, malonic acid diesters, acetoacetate esters, 2-acetoacetoxyethyl methacrylate, acetylacetone, and cyanoacetate esters. Malonic acid diesters are not particularly limited, but examples include dimethyl malonate, diethyl malonate, di-n-butyl malonate, di-tert-butyl malonate, di-2-ethylhexyl malonate, methyl n-butyl malonate, ethyl n-butyl malonate, methyl sec-butyl malonate, ethyl sec-butyl malonate, methyl tert-butyl malonate, ethyl tert-butyl malonate, diethyl methylmalonate, dibenzyl malonate, diphenyl malonate, benzylmethyl malonate, ethylphenyl malonate, tert-butylphenyl malonate, and isopropylidene malonate. Examples of acetoacetate esters are not particularly limited, but include methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate, t-butyl acetoacetate, benzyl acetoacetate, and phenyl acetoacetate.

[0051] The amine compounds are not particularly limited, but examples include dibutylamine, diphenylamine, aniline, N-methylaniline, carbazole, bis(2,2,6,6-tetramethylpiperidinyl)amine, di-n-propylamine, diisopropylamine (dissociation temperature 130°C), isopropylethylamine, 2,2,4- or 2,2,5-trimethylhexamethyleneamine, N-isopropylcyclohexylamine (dissociation temperature 140°C), dicyclohexylamine (dissociation temperature 130°C), and bis(3,5,5-trimethylcyclo Hexyl)amine, piperidine, 2,6-dimethylpiperidine (dissociation temperature 130°C), tert-butylmethylamine, tert-butylethylamine (dissociation temperature 120°C), tert-butylpropylamine, tert-butylbutylamine, tert-butylbenzylamine (dissociation temperature 120°C), tert-butylphenylamine, 2,2,6-trimethylpiperidine, 2,2,6,6-tetramethylpiperidine (dissociation temperature 80°C), (dimethylamino)-2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethyl Examples include 4-4-piperidine, 6-methyl-2-piperidine, and 6-aminocaproic acid.

[0052] The imine compounds are not particularly limited, but examples include ethyleneimine, polyethyleneimine, and 1,4,5,6-tetrahydropyrimidine.

[0053] Examples of oxime compounds are not particularly limited, but include formaldehyde oxime, acetaldehyde oxime, acetoxime, methyl ethyl ketoxime (dissociation temperature 130°C), cyclohexanone oxime, diacetyl monooxime, benzophenooxime, 2,2,6,6-tetramethylcyclohexanone oxime, diisopropyl ketone oxime, methyl tert-butyl ketone oxime, diisobutyl ketone oxime, methyl isobutyl ketone oxime, methyl isopropyl ketone oxime, methyl 2,4-dimethylpentyl ketone oxime, methyl 3-ethylheptyl ketone oxime, methyl isoamyl ketone oxime, n-amyl ketone oxime, 2,2,4,4-tetramethyl-1,3-cyclobutanedione monooxime, 4,4'-dimethoxybenzophenone oxime, and 2-heptanone oxime.

[0054] Examples of carbamic acid compounds include phenyl N-phenylcarbamate, although these are not particularly limited.

[0055] Urea-based compounds are not particularly limited, but examples include urea, thiourea, and ethyleneurea.

[0056] Acid amide (lactam) compounds are not particularly limited, but examples include acetanilide, N-methylacetamide, acetic acid amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam, pyrrolidone, 2,5-piperazinedione, and laurolactam.

[0057] Examples of acid-imide compounds include succinimide, maleimide, and phthalimide.

[0058] Triazole compounds are not particularly limited, but examples include 1,2,4-triazole and benzotriazole.

[0059] Pyrazole compounds are not particularly limited, but examples include pyrazole, 3,5-dimethylpyrazole (dissociation temperature 120°C), 3,5-diisopropylpyrazole, 3,5-diphenylpyrazole, 3,5-di-tert-butylpyrazole, 3-methylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3,5-dimethylpyrazole, and 3-methyl-5-phenylpyrazole.

[0060] Mercaptan compounds are not particularly limited, but examples include butyl mercaptan, dodecyl mercaptan, and hexyl mercaptan.

[0061] While not particularly limited, sodium bisulfite is one example of a bisulfite.

[0062] These blocking agents may be used individually or in combination of two or more. For some of the compounds exemplified above, the dissociation temperature is also indicated as the temperature at which the isocyanate group is regenerated.

[0063] The dissociation temperature of the blocking agent is preferably 60°C to 230°C, more preferably 80°C to 200°C, even more preferably 100°C to 180°C, and even more preferably 110°C to 160°C. Within this range of dissociation temperatures, the storage stability of the ink composition can be further improved.

[0064] Commercially available blocked isocyanates include, but are not limited to, "Takenate WB-3021" (product name, manufactured by Mitsui Chemicals, Inc.), "BN-69" and "BN-11" from the "Elastron" series (product names, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Meikanate TP-10, Meikanate NS-1, "SU-268A", "NBP-8730", and "NBP-211" (product names, manufactured by Meisei Chemical Industry Co., Ltd.). These blocked isocyanates may be used individually or in combination of two or more.

[0065] The crosslinking agent content in the clear ink is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 1.5% by mass or more, and even more preferably 2% by mass or more, relative to the total amount of clear ink. On the other hand, there is no upper limit to the crosslinking agent content in the clear ink, but it is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less, relative to the total amount of clear ink. When the crosslinking agent content in the clear ink is within this range, the friction fastness of the resulting image can be improved.

[0066] The crosslinking agent in the clear ink more preferably includes one or more compounds selected from the above examples, specifically blocked isocyanate compounds, carbodiimide compounds, and oxazoline compounds. This improves the friction fastness of the resulting image.

[0067] 1.1.3.Water Clear ink contains water. Examples of water include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, and distilled water, as well as ultrapure water, which has reduced ionic impurities. Furthermore, using water sterilized by ultraviolet irradiation or the addition of hydrogen peroxide can suppress the growth of bacteria and fungi when storing clear ink for a long period of time.

[0068] The water content is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, and particularly preferably 60% by mass or more, relative to the total amount of clear ink. There is no particular upper limit to the water content, but for example, it is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, relative to the total amount of clear ink.

[0069] 1.1.4. Other ingredients Clear ink may contain the following components:

[0070] (Colorants) Clear ink may contain colorants such as pigments, but if it contains colorants, it is preferable that the amount is as small as possible. If the clear ink contains colorants, the amount is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, and it is particularly preferable that it does not contain any colorants. It is also preferable that the amount of first resin particles in the clear ink is 80% by mass or more, relative to the total amount of colorants and resin in the clear ink.

[0071] In this way, since the clear ink contains virtually no colorants, coloring by the colorants in the clear ink is reduced, and the tonal changes of the image due to the white ink are less likely to occur. In addition, the resin content in the clear ink is increased, which improves the friction fastness of the resulting image.

[0072] (Moisturizer) The clear ink may contain a humectant. While not particularly limited, examples of humectants include glycerin, 2-pyrrodrin, urea, triethanolamine, propylene glycol, 1-(2-hydroxyethyl)-2-pyrrodrin, trimethylolpropane, triethylene glycol, 1,5-pentanediol, triethylene glycol monomethyl ether, and aminocoat. These can be used individually or in combination of two or more.

[0073] (Organic solvents) The clear ink may contain an organic solvent. Examples of organic solvents include esters, alkylene glycol ethers, cyclic esters, amides, alcohols, and polyhydric alcohols.

[0074] Examples of esters include glycol monoacetates and glycol diesters.

[0075] The alkylene glycol ethers can be monoethers or diethers of alkylene glycols, with alkyl ethers being preferred. Specific examples include alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monobutyl ether, and tetraethylene glycol monomethyl ether; and alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, diethylene glycol dibutyl ether, triethylene glycol diethyl ether, and tripropylene glycol dimethyl ether.

[0076] Examples of cyclic esters include cyclic esters (lactones) such as β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone, as well as compounds in which the hydrogen atoms of the methylene group adjacent to the carbonyl group are substituted with alkyl groups having 1 to 4 carbon atoms.

[0077] Examples of amides include cyclic amides and acyclic amides. Examples of acyclic amides include alkoxyalkylamides.

[0078] Examples of cyclic amides include lactams. Examples of lactams include pyrrolidones such as 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone.

[0079] Examples of alkoxyalkylamides include 3-methoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, and 3-methoxy-N,N-methylethylpropionamide.

[0080] Examples of alcohols include compounds in which one hydrogen atom of an alkane is replaced by a hydroxyl group. Alkanes with 10 or fewer carbon atoms are preferred, those with 6 or fewer carbon atoms are more preferred, and those with 3 or fewer carbon atoms are even more preferred. Alkanes have 1 or more carbon atoms, preferably 2 or more. Alkanes may be linear or branched.

[0081] Examples of alcohols include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol, 2-phenoxyethanol, benzyl alcohol, and phenoxypropanol.

[0082] Polyhydric alcohols are molecules that contain two or more hydroxyl groups. Polyhydric alcohols can be further classified into, for example, alkanediols and polyols.

[0083] Alkanediols include, for example, compounds in which an alkane is substituted with two hydroxyl groups. Examples of alkanediols include 1,2-alkanediols, which are a general term for compounds in which hydroxyl groups are substituted at the 1st and 2nd positions of an alkane, and other alkanediols other than 1,2-alkanediols.

[0084] Examples of 1,2-alkanediols include ethylene glycol, 1,2-propanediol (propylene glycol), and 1,2-butanediol (1,2BD).

[0085] Other examples of alkanediols include 1,3-propanediol, 1,3-butylene glycol (also known as 1,3-butanediol), 1,4-butanediol, 2,3-butanediol, and 1,5-pentanediol.

[0086] Examples of polyols include condensates formed by the intermolecular condensation of two or more alkanediol molecules via hydroxyl groups, and compounds having three or more hydroxyl groups.

[0087] Examples of condensates formed by the intermolecular condensation of two or more alkanediol molecules at their hydroxyl groups include dialkylene glycols such as diethylene glycol and dipropylene glycol, and trialkylene glycols such as triethylene glycol and tripropylene glycol.

[0088] Compounds having three or more hydroxyl groups are compounds with an alkane or polyether structure as their backbone and containing three or more hydroxyl groups. Examples of compounds having three or more hydroxyl groups include glycerin, trimethylolethane, trimethylolpropane, 1,2,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, and polyoxypropylenetriol.

[0089] Organic solvents may be used individually or in combination of two or more types.

[0090] Among these, the organic solvent preferably contains alkanediols, more preferably 1,2-alkanediols, and particularly preferably propylene glycol. When the organic solvent contains these solvents, a resin layer can be formed well near the surface of the fabric. As a result, the color development of the printed material tends to be good.

[0091] The content of the organic solvent is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, even more preferably 15 to 35% by mass, and particularly preferably 20 to 30% by mass, relative to the total amount of clear ink. When the content of the organic solvent is within the above range, the color development of the printed material tends to be good.

[0092] (Surfactants) The clear ink may contain a surfactant. The surfactant has the function of adjusting the surface tension of the composition, for example, adjusting the wettability with fabric. Among surfactants, acetylene glycol-based surfactants, silicone-based surfactants, and fluorine-based surfactants can be preferably used.

[0093] Acetylene glycol-based surfactants are not particularly limited, but examples include Surfinol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, DF110D (all of the above are brand names, manufactured by Air Products & Chemicals), and Olph. Examples include In B, Y, P, A, STG, SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP.4001, EXP.4036, EXP.4051, EXP.4300, AF-103, AF-104, AK-02, SK-14, AE-3 (all product names, manufactured by Nisshin Chemical Industry Co., Ltd.), and Acetyleneol E00, E00P, E40, E100 (all product names, manufactured by Kawaken Fine Chemical Co., Ltd.).

[0094] While not particularly limited, polysiloxane compounds are preferred as silicone-based surfactants. While not particularly limited, examples of polysiloxane compounds include polyether-modified organosiloxanes. Examples of commercially available polyether-modified organosiloxanes include BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (all trade names, manufactured by BYK-Chemie Japan), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF- Examples include 615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (all product names, manufactured by Shin-Etsu Chemical Co., Ltd.), Silface SAG002, 005, 503A, 008 (all product names, manufactured by Nisshin Chemical Industry Co., Ltd.).

[0095] As fluorine-based surfactants, it is preferable to use fluorine-modified polymers. Specific examples include BYK-3440 (manufactured by Bic Chemie Japan), Surflon S-241, S-242, S-243 (all trade names, manufactured by AGC Seimi Chemical Co., Ltd.), and Futergent 215M (manufactured by Neos Co., Ltd.).

[0096] When a surfactant is included in the ink composition, multiple types may be included. The amount of surfactant included in the ink composition can be 0.1% to 2% by mass, preferably 0.3% to 1.5% by mass, and more preferably 0.4% to 1.0% by mass, based on the total mass of the ink composition.

[0097] (Additives) Clear ink may contain additives. Examples of additives include pH adjusters, sugars, chelating agents, preservatives / fungal agents, rust inhibitors, and others.

[0098] pH adjusters are not particularly limited, but include appropriate combinations of acids, bases, weak acids, and weak bases. Examples of acids and bases used in such combinations include, as inorganic acids, sulfuric acid, hydrochloric acid, nitric acid, etc.; as inorganic bases, lithium hydroxide, sodium hydroxide, potassium hydroxide, potassium dihydrogen phosphate, disodium hydrogen phosphate, potassium carbonate, sodium carbonate, sodium bicarbonate, ammonia, etc.; as organic bases (alkaline agents), triethanolamine, diethanolamine, monoethanolamine, trippropanolamine, triisopropanolamine, diisopropanolamine, trishydroxymethylaminomethane (THAM), etc.; and as organic acids, adipic acid, citric acid, succinic acid, lactic acid, N,N-bis(2- Good's buffer, phosphate buffer, citrate buffer, Tris buffer, etc., containing hydroxyethyl)-2-aminoethanesulfonic acid (BES), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), morpholinoethanesulfonic acid (MES), carbamoylmethyliminobisacetic acid (ADA), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-(2-acetamide)-2-aminoethanesulfonic acid (ACES), cholamine hydrochloride, N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), acetamidoglycine, tricine, glycinamide, bicine, etc. may also be used. Furthermore, it is preferable that some or all of these pH adjusting agents include tertiary amines such as triethanolamine and triisopropanolamine, and carboxyl group-containing organic acids such as adipic acid, citric acid, succinic acid, and lactic acid, as this allows for a more stable pH buffering effect.

[0099] Specific examples of sugars include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose.

[0100] Examples of chelating agents include ethylenediaminetetraacetic acid and its salts (such as disodium dihydrogen diacetic acid salt, or nitrilotriacetate, hexametaphosphate, pyrophosphate, or metaphosphate of ethylenediamine).

[0101] Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel IB, and Proxel TN (all manufactured by Lonza Japan, trade names), and 4-chloro-3-methylphenol (such as Preventol CMK from Bayer).

[0102] Examples of rust inhibitors include benzotriazole, acidic sulfites, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite. Among these, benzotriazole is particularly preferred.

[0103] Other additives include viscosity modifiers, fungicides, antioxidants, and oxygen absorbers.

[0104] 1.1.5. Manufacturing and Physical Properties The clear ink is applied to the fabric by an inkjet method, and its viscosity at 20°C is preferably 1.5 mPa·s to 15 mPa·s, more preferably 1.5 mPa·s to 7 mPa·s, and even more preferably 1.5 mPa·s to 5.5 mPa·s. Since the clear ink is applied to the fabric by an inkjet method, it is easy to efficiently form a predetermined image on the fabric.

[0105] From the viewpoint of ensuring appropriate wetting and spreading properties on fabric, the surface tension of the clear ink at 25°C is 40 mN / m or less, preferably 38 mN / m or less, and more preferably 35 mN / m or less. Furthermore, a surface tension of 20 mN / m or more is preferred, and 25 mN / m or more is more preferred.

[0106] Surface tension can be measured using an automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) by checking the surface tension when a platinum plate is wetted with the composition in an environment of 25°C.

[0107] Clear ink is obtained by mixing the aforementioned components in any order and removing impurities by filtration or other means as necessary. A preferred method for mixing the components is to sequentially add the materials to a container equipped with a stirring device such as a mechanical stirrer or magnetic stirrer and then stir-fry them. As for filtration methods, centrifugal filtration, filter filtration, etc., can be performed as needed.

[0108] 1.2. White ink The white ink of this embodiment contains a white pigment, second resin particles, and water.

[0109] 1.2.1. White Pigments White ink contains a white pigment. Examples of white pigments include CI Pigment White 1, which is basic lead carbonate; CI Pigment White 4, which is zinc oxide; CI Pigment White 5, which is a mixture of zinc sulfide and barium sulfate; CI Pigment White 6, which is titanium dioxide; CI Pigment White 6:1, which is titanium dioxide containing other metal oxides; CI Pigment White 7, which is zinc sulfide; CI Pigment White 18, which is calcium carbonate; CI Pigment White 19, which is clay; CI Pigment White 20, which is titanium mica; CI Pigment White 21, which is barium sulfate; CI Pigment White 22, which is gypsum; CI Pigment White 26, which is magnesium oxide and silicon dioxide; CI Pigment White 27, which is silicon dioxide; and CI Pigment White 28, which is anhydrous calcium silicate. Among these, it is preferable to use titanium dioxide such as CI Pigment White 6, which has excellent color development and opacity as an image base.

[0110] The average particle size of the white pigment is preferably between 100 nm and 500 nm, more preferably between 50 nm and 450 nm, and even more preferably between 200 nm and 400 nm. Setting the average particle size of the white pigment within this range tends to ensure ejection stability from the inkjet head. It also tends to improve the opacity of the white pigment as a base for printed images. In this specification, "average particle size" refers to the volume-based particle size distribution, which is the particle size at a cumulative distribution of 50 vol% unless otherwise specified. The average particle size is measured using the dynamic light scattering method or the laser diffraction method described in JIS Z8825. Specifically, a particle size analyzer that uses the dynamic light scattering method as its measurement principle (e.g., "Microtrac UPA," manufactured by Nikkiso Co., Ltd.) can be used.

[0111] The content of the white pigment is preferably 1 to 30% by mass, more preferably 2 to 25% by mass, even more preferably 4 to 20% by mass, and particularly preferably 6 to 15% by mass, relative to the total amount of white ink. When the content of the white pigment is within the above range, the printed material exhibits good color development and also good friction fastness.

[0112] White pigments may be dispersed using a pigment dispersant. Alternatively, the pigment surface may be oxidized or sulfonated with ozone, hypochlorous acid, fuming sulfuric acid, etc., to form a self-dispersing pigment which can then be dispersed for use.

[0113] Pigment dispersants have the function of dispersing pigments in ink. Pigment dispersants may be water-soluble, but those that are not completely water-soluble are preferred. It is thought that they disperse pigments by partially or completely binding to or adsorbing to the pigment, thereby increasing the hydrophilicity of the pigment surface.

[0114] Pigment dispersants are polymer compounds, and examples include acrylic resins and their salts such as poly(meth)acrylic acid, (meth)acrylic acid-acrylonitrile copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid copolymer, vinylnaphthalene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-α-methylstyrene-(meth)acrylic acid copolymer, and styrene-α-methylstyrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer.

[0115] Furthermore, examples of pigment dispersants include maleic acid-based resins and their salts, such as styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-maleic acid copolymer, and vinyl acetate-maleic acid ester copolymer; urethane-based resins and their salts, with or without crosslinking structures; polyvinyl alcohols; and resins such as vinyl acetate-crotonic acid copolymer and its salts.

[0116] Furthermore, acrylic resins may be copolymers of acrylic monomers (acrylic monomers) as described above, or copolymers of acrylic monomers with other monomers. For example, acrylic vinyl resin, which is a copolymer of vinyl monomers as the other monomer, is also called an acrylic resin. Also, among the styrene resins mentioned above, those which are copolymers of styrene monomers and acrylic monomers are included in acrylic resins. Moreover, when referring to acrylic resins, their salts and esterified products are also included.

[0117] Examples of commercially available pigment dispersants include X-200, X-1, X-205, X-220, X-228 (manufactured by Seikoh PMC), Nopcospers® 6100, 6110 (manufactured by Sunnopco Corporation), Joncryl 67, 586, 611, 678, 680, 682, 819 (manufactured by BASF), DISPERBYK-190 (manufactured by Bic Chemie Japan Co., Ltd.), N-EA137, N-EA157, N-EA167, N-EA177, N-EA197D, N-EA207D, and E-EN10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0118] Examples of commercially available acrylic pigment dispersants include BYK-187, BYK-190, BYK-191, BYK-194N, BYK-199 (manufactured by Bic Chemie Japan Co., Ltd.), Aron A-210, A6114, AS-1100, AS-1800, A-30SL, A-7250, and CL-2 (manufactured by Toagosei Co., Ltd.).

[0119] Commercially available urethane-based pigment dispersants include BYK-182, BYK-183, BYK-184, BYK-185 (manufactured by Bic Chemi Japan Co., Ltd.), TEGO Disperse710 (manufactured by Evonic Tego Chemi), and Borchi® Gen1350 (manufactured by OMG Borschers).

[0120] The pigment dispersant is preferably an anionic pigment dispersant. An "anionic pigment dispersant" refers to a pigment dispersant that has a negative charge as a whole, and it is preferable that it has one or more anionic groups selected from carboxyl groups, sulfonic acid groups, phosphate groups, etc.

[0121] A pigment is anionic if it has a negative charge as a whole, and it is preferable that it has one or more anionic groups selected from carboxyl groups, sulfonic acid groups, phosphate groups, etc. The anionic groups may be directly present on the pigment surface, or they may be present via an anionic resin dispersant adsorbed or bound to the pigment.

[0122] The pigment dispersant may be used alone or in combination of two or more types. The total content of the pigment dispersant is preferably 0.1% to 30% by mass, more preferably 0.5% to 25% by mass, even more preferably 1% to 20% by mass, and particularly preferably 1.5% to 15% by mass, relative to the total amount of white ink. By having a pigment dispersant content of 0.1% by mass or more, the dispersion stability of the pigment can be ensured. Furthermore, if the pigment dispersant content is 30% by mass or less, the viscosity of the white ink can be reduced.

[0123] Furthermore, it is even more preferable that the weight-average molecular weight of the pigment dispersant be 500 or higher. Using such a pigment dispersant tends to result in less odor and improved dispersion stability of the pigment.

[0124] When dispersing a white pigment with a pigment dispersant, the ratio of pigment to pigment dispersant is preferably 10:1 to 1:10, and more preferably 4:1 to 1:3.

[0125] 1.2.2.Second resin particles The white ink contains second resin particles. The second resin particles in the white ink are the same as the first resin particles in the clear ink described above, and a detailed explanation is omitted. The second resin particles in the white ink may be the same as or different from the first resin particles in the clear ink described above.

[0126] The 100% modulus of the second resin particle may be 6 MPa or less.

[0127] The 100% modulus of the second resin particles is preferably 5 to 25 MPa, more preferably 10 to 20 MPa, and even more preferably 5 to 20 MPa. When the 100% modulus of the resin particles is 10 MPa or higher, the second resin particles contained in the white ink become softer, resulting in a better texture for the resulting printed material. Furthermore, it is easier to achieve a good texture for the printed material even when the amount of white ink applied is increased.

[0128] As the 100% modulus of the resin particles, a tensile test is performed by heating the resin particles at 170°C for 5 minutes to create a film with a thickness of approximately 60 μm. The value obtained by measuring the tensile stress when the film has stretched to 100% of its original length is adopted in a tensile test conducted under conditions of a tensile test gauge length of 20 mm and a tensile speed of 100 mm / min.

[0129] 1.2.3.Water White ink contains water. The water is the same as described in the section on clear ink, so a detailed explanation is omitted.

[0130] 1.2.4. Other ingredients White ink may contain other components. Such components include humectants, organic solvents, surfactants, and additives, and are the same as those described in the section on clear ink, so a detailed explanation is omitted.

[0131] 1.2.5. Manufacturing and Physical Properties The white ink is applied to the fabric by an inkjet method, and its viscosity at 20°C is preferably 1.5 mPa·s to 15 mPa·s, more preferably 1.5 mPa·s to 7 mPa·s, and even more preferably 1.5 mPa·s to 5.5 mPa·s. Since the white ink is applied to the fabric by an inkjet method, it is easy to efficiently form a predetermined image on the fabric.

[0132] From the viewpoint of ensuring proper wetting and spreading properties on fabric, the surface tension of the white ink at 25°C is 40 mN / m or less, preferably 38 mN / m or less, and more preferably 35 mN / m or less. Furthermore, a surface tension of 20 mN / m or more is preferred, and 25 mN / m or more is more preferred.

[0133] Surface tension can be measured using an automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) by checking the surface tension when a platinum plate is wetted with the composition in an environment of 25°C.

[0134] White ink is obtained by mixing the aforementioned components in any order and removing impurities by filtration or other means as necessary. A preferred method for mixing the components is to sequentially add the materials to a container equipped with a stirring device such as a mechanical stirrer or magnetic stirrer and then stir-fry them. As for filtration methods, centrifugal filtration, filter filtration, etc., can be performed as needed.

[0135] 1.3.Surface tension In the ink set of this embodiment, the surface tension of the clear ink is 4.5 mN / m or greater than the surface tension of the white ink. That is, the clear ink and the white ink are set so that the surface tension of the clear ink is 4.5 mN / m or greater than the surface tension of the white ink.

[0136] In the ink set, it is more preferable that the surface tension of the clear ink is 5 mN / m or greater than the surface tension of the white ink, even more preferable that it is 6 mN / m or greater, and even more preferable that it is 7 mN / m or greater.

[0137] By doing so, when the clear ink adheres to the fabric, it tends to aggregate first, and the clear ink acts as a base, increasing the adhesion of the white ink to the fabric, thus improving friction fastness (especially dry friction fastness).

[0138] If the surface tension of clear ink is higher than that of white ink, the clear ink will be relatively less wettable and less permeable, and as a result, it is thought to be more likely to aggregate before it can penetrate. Therefore, it is thought that the clear ink aggregates early, and the clear ink containing a large amount of primary resin particles becomes the base, improving the adhesion between the fabric and the coating film, and making it less likely for peeling to occur at the interface between the fabric and the coating film.

[0139] 1.4. Modulus In the ink set of this embodiment, it is more preferable that the 100% modulus of the first resin particles contained in the clear ink is greater than the 100% modulus of the second resin particles contained in the white ink. By selecting the first and second resin particles in this way, the balance between the friction fastness of the resulting image and the texture of the printed material can be further improved.

[0140] 1.5. Other Inks The ink set of this embodiment may include various inks and compositions in addition to clear ink and white ink. Examples of such inks and compositions include known inkjet inks containing non-white colorants and processing liquid compositions containing flocculants. Furthermore, the ink set of this embodiment may include multiple types of the above-mentioned clear ink, white ink, known non-white inks, and known processing liquid compositions.

[0141] 1.6. Effects and Effects According to the ink set of this embodiment, by using a clear ink containing resin particles and making the surface tension of the clear ink 4.5 mN / m or more greater than the surface tension of the white ink, the clear ink acts as a base, increasing the adhesion of the white ink to the fabric, thereby enabling the formation of an image with good friction fastness.

[0142] 2. Inkjet Printing Recording Method The inkjet printing recording method according to this embodiment is an inkjet printing recording method using an ink set that includes the above-mentioned clear ink, which is a printing inkjet composition containing first resin particles, a crosslinking agent, and water, and the above-mentioned white ink, which is a printing inkjet composition containing a white pigment, second resin particles, and water.

[0143] Furthermore, as mentioned above, the content of the first resin particles is 4.5% by mass or more relative to the total amount of clear ink, and the surface tension of the clear ink is 4.5 mN / m or more greater than the surface tension of the white ink.

[0144] The inkjet printing recording method according to this embodiment includes a clear ink application step in which clear ink is ejected by an inkjet method and adhered to the fabric, and a white ink application step in which white ink is ejected by an inkjet method and adhered to the fabric. The clear ink application step and the white ink application step are performed simultaneously on the same area of ​​the fabric, or the clear ink application step is performed first.

[0145] 2.1.Fabric The inkjet printing method is applied to textiles.

[0146] The fabric is not particularly limited. The materials that make up the fabric are not particularly limited and include, for example, natural fibers such as cotton, linen, wool, and silk; synthetic fibers such as polypropylene, polyester, acetate, triacetate, polyamide, and polyurethane; and biodegradable fibers such as polylactic acid. Blends of these fibers are also acceptable. The fabric may be made from the above-mentioned fibers in any form, such as woven, knitted, or nonwoven fabric, or it may be a blended fabric.

[0147] The fabric may be made from the above-mentioned fibers in any form, such as woven, knitted, or nonwoven. Furthermore, the basis weight of the fabric used in this embodiment is not particularly limited and may be between 1.0 oz and 10.0 oz, preferably between 2.0 oz and 9.0 oz, more preferably between 3.0 oz and 8.0 oz, and even more preferably between 4.0 oz and 7.0 oz. Good recording can be achieved if the basis weight of the fabric is within this range.

[0148] In this embodiment, examples of fabrics include cloth, clothing, and other fashion accessories. Cloths include woven fabrics, knitted fabrics, nonwoven fabrics, etc. Clothing and other fashion accessories include sewn T-shirts, handkerchiefs, scarves, towels, tote bags, cloth bags, curtains, sheets, bedspreads, wallpaper and other furniture, as well as fabrics before and after cutting as parts before sewing. These forms include long rolls, cut to predetermined sizes, and product shapes.

[0149] As the fabric, cotton fabric that has been pre-colored with dye may be used. Examples of dyes used to pre-color the fabric include water-soluble dyes such as acid dyes and basic dyes, disperse dyes used in combination with dispersants, and reactive dyes. Furthermore, the fabric does not need to contain a flocculant. Even with such a fabric, the above-described inkjet printing ink composition can be used to obtain an image with good friction fastness.

[0150] Furthermore, it is preferable to use a fabric that contains cotton. When the fabric contains cotton, it may be possible to obtain the effect of improved friction fastness by improving the adhesion between the fabric and the recording layer.

[0151] 2.2. Clear ink application process and white ink application process The inkjet printing recording method according to this embodiment is performed by applying the above-mentioned clear ink and white ink to the fabric using an inkjet method. The inkjet method can be performed, for example, using the recording apparatus described below.

[0152] An example of an inkjet printing apparatus (recording apparatus) equipped with an inkjet head, applicable to the inkjet printing recording method according to this embodiment, will be described with reference to Figure 1.

[0153] In Figure 1, the scale of each layer and component has been altered from the actual scale in order to make them recognizable. Also, for the sake of explanation, Figure 1 illustrates the X, Y, and Z axes as three mutually orthogonal axes, with the tip of the arrow indicating the axis direction being the "+ side" and the base being the "- side". The direction parallel to the X axis is called the "X-axis direction", the direction parallel to the Y axis is called the "Y-axis direction", and the direction parallel to the Z axis is called the "Z-axis direction".

[0154] 2.2.1.Overall schematic configuration Figure 1 is a schematic diagram showing the overall configuration of the recording device 100. First, the overall configuration of the recording device 100 will be explained with reference to Figure 1.

[0155] As shown in Figure 1, the recording device 100 includes a media transport unit 20, a media contact unit 60, a belt support unit 91, a printing unit 40, a heating unit 27, a washing unit 50, and the like. In the recording device 100, at least one of the media contact unit 60 and the belt support unit 91 corresponds to a heating unit that heats the endless belt 23. It also has a control unit 1 that controls each of these units. Each part of the recording device 100 is attached to a frame unit 90.

[0156] If a heating unit is provided to heat the endless belt, it only needs to be located upstream of the printing unit 40 in the transport direction, and may be located in a different place from the media contact unit 60 and the belt support unit 91. For example, the heating unit may be located upstream of the media contact unit 60 in the transport direction. With this configuration, the heating unit can also dry the wet endless belt 23 during cleaning. Furthermore, the heating unit may heat the endless belt without contact.

[0157] The media transport unit 20 transports the fabric 95 in the transport direction. The media transport unit 20 includes a media supply unit 10, transport rollers 21 and 22, an endless belt 23, a belt rotating roller 24, a belt drive roller 25 as a drive roller, transport rollers 26 and 28, and a media recovery unit 30.

[0158] 2.2.2. Media Transport Section First, the transport path of the fabric 95 from the media supply unit 10 to the media recovery unit 30 will be described. In Figure 1, the direction along the direction in which gravity acts is defined as the Z-axis direction, the direction in which the fabric 95 is transported in the printing unit 40 is defined as the +X-axis direction, and the width direction of the fabric 95 that intersects both the Z-axis direction and the X-axis direction is defined as the Y-axis direction. The positional relationship along the transport direction of the fabric 95 or the movement direction of the endless belt 23 is also referred to as the "upstream side" and the "downstream side."

[0159] The media supply unit 10 supplies the fabric 95 on which the image is formed to the printing unit 40. The media supply unit 10 has a supply shaft 11 and a bearing 12. The supply shaft 11 is formed in a cylindrical or columnar shape and is rotatable in the circumferential direction. The strip-shaped fabric 95 is wound in a roll on the supply shaft 11. The supply shaft 11 is detachably attached to the bearing 12. This allows the fabric 95, which is pre-wound on the supply shaft 11, to be attached to the bearing 12 together with the supply shaft 11.

[0160] The bearing section 12 rotatably supports both axial ends of the supply shaft section 11. The medium supply section 10 has a rotation drive section (not shown) that rotates the supply shaft section 11. The rotation drive section rotates the supply shaft section 11 in the direction in which the fabric 95 is fed out. The operation of the rotation drive section is controlled by the control section 1. The conveyor rollers 21 and 22 relay the fabric 95 from the medium supply section 10 to the endless belt 23.

[0161] The endless belt 23 is held between at least two rollers that rotate the endless belt 23, and as the endless belt 23 rotates, it supports the fabric 95 and conveys it in the conveying direction (+X axis direction). Specifically, the endless belt 23 is a seamless belt formed by connecting both ends of a strip-shaped belt without any joints, and is stretched between two rollers, the belt rotating roller 24 and the belt driving roller 25.

[0162] The endless belt 23 is held under a predetermined tension so that the portion between the belt rotating roller 24 and the belt driving roller 25 is horizontal. An adhesive 29 for adhering the fabric 95 is applied to the surface (support surface) 23a of the endless belt 23. In other words, the endless belt 23 has an adhesive layer consisting of the adhesive 29. The fabric 95 is attached to the endless belt 23 via the adhesive 29. The endless belt 23 is supplied from the conveying roller 22 and supports (holds) the fabric 95, which is in close contact with the adhesive 29, at the medium contact section 60, which will be described later.

[0163] Preferably, the adhesive 29 increases in tackiness when heated. By using an adhesive 29 that increases in tackiness when heated, the fabric 95 can be adhered well to the adhesive layer. An example of such an adhesive 29 is a hot-melt adhesive mainly composed of thermoplastic elastomer SIS (styrene-isoprene-styrene).

[0164] The belt rotating roller 24 and the belt driving roller 25 support the inner circumferential surface 23b of the endless belt 23. Between the belt rotating roller 24 and the belt driving roller 25, there is a contact portion 69, a belt support portion 91, and a platen 46 that support the endless belt 23. The contact portion 69 is located in the region facing the pressing portion 61 (described later) via the endless belt 23, the platen 46 is located in the region facing the printing portion 40 via the endless belt 23, and the belt support portion 91 is located between the contact portion 69 and the platen 46. By supporting the endless belt 23 with the contact portion 69, the belt support portion 91, and the platen 46, vibrations of the endless belt 23 that occur when the endless belt 23 is moved can be suppressed.

[0165] The belt-driven roller 25 is a drive unit that conveys the fabric 95 in the conveying direction by rotating the endless belt 23, and has a motor (not shown) that rotates the belt-driven roller 25. The belt-driven roller 25 is located downstream of the printing unit 40 in the conveying direction of the fabric 95, and the belt-rotating roller 24 is located upstream of the printing unit 40. When the belt-driven roller 25 is rotated, the endless belt 23 rotates in conjunction with the rotation of the belt-driven roller 25, and the belt-rotating roller 24 rotates due to the rotation of the endless belt 23. As the endless belt 23 rotates, the fabric 95 supported by the endless belt 23 is conveyed in the conveying direction (+X axis direction), and an image is formed on the fabric 95 in the printing unit 40, which will be described later.

[0166] In the example shown in Figure 1, the fabric 95 is supported on the side of the endless belt 23's surface 23a facing the printing unit 40 (+Z-axis side), and the fabric 95 is transported together with the endless belt 23 from the belt rotating roller 24 side to the belt driving roller 25 side. On the side of the endless belt 23's surface 23a facing the washing unit 50 (-Z-axis side), only the endless belt 23 moves from the belt driving roller 25 side to the belt rotating roller 24 side.

[0167] The conveyor roller 26 peels the fabric 95 with the image formed on it from the adhesive 29 of the endless belt 23. The conveyor rollers 26 and 28 relay the fabric 95 from the endless belt 23 to the media recovery unit 30.

[0168] The media recovery unit 30 recovers the fabric 95 that has been transported by the media transport unit 20. The media recovery unit 30 has a winding shaft 31 and a bearing unit 32. The winding shaft 31 is formed in a cylindrical or columnar shape and is rotatable in the circumferential direction. The strip-shaped fabric 95 is wound onto the winding shaft 31 in a roll shape. The winding shaft 31 is detachably attached to the bearing unit 32. As a result, the fabric 95 wound onto the winding shaft 31 can be removed together with the winding shaft 31.

[0169] The bearing section 32 rotatably supports both ends of the winding shaft section 31 in the axial direction. The media recovery section 30 has a rotation drive section (not shown) that rotates the winding shaft section 31. The rotation drive section rotates the winding shaft section 31 in the direction in which the fabric 95 is wound. The operation of the rotation drive section is controlled by the control section 1.

[0170] Next, we will describe the heating section, printing section 40, heating unit 27, and washing unit 50, which are located along the media transport section 20.

[0171] 2.2.3. Heating section It is preferable that a heater for heating the endless belt 23 is provided in at least one of the contact portion 69 and the belt support portion 91. The heater constitutes the heating portion. When a heater is provided in the contact portion 69, the pressing portion 61 can apply pressing force and heat to the endless belt 23, which is preferable in that it can improve the adhesion of the fabric 95 to the endless belt 23. Therefore, when a heater is provided in either the contact portion 69 or the belt support portion 91, it is more preferable to provide it in the contact portion 69.

[0172] The heating section softens the adhesive layer by heating it, thereby improving its adhesion to the fabric 95 and the adhesive layer. This suppresses the movement of the fabric 95 on the endless belt 23, resulting in good conveying accuracy.

[0173] A heater is provided on at least one of the contact portion 69 and the belt support portion 91, and when the endless belt 23 is heated, the temperature of the surface 23a of the endless belt 23 is preferably 80 degrees Celsius or lower, more preferably 70 degrees Celsius or lower, and even more preferably 60 degrees Celsius or lower. When the temperature of the surface 23a of the endless belt 23 is within the above range, the reactivity of resin particles contained in the clear ink or white ink is suppressed, and the belt may be easier to clean. The lower limit of the temperature of the surface 23a of the endless belt 23 is as long as it allows the adhesive layer to exhibit its adhesive properties, preferably 30 degrees Celsius or higher, more preferably 35 degrees Celsius or higher, and even more preferably 40 degrees Celsius or higher. The temperature of the surface 23a of the endless belt 23 can be measured by, for example, a radiant thermometer or a contact thermometer, and it is more preferable to measure it by a radiant thermometer.

[0174] If a heater is provided on at least one of the contact portion 69 and the belt support portion 91, a temperature detection unit (not shown) for detecting the surface temperature of the endless belt 23 may be provided. For example, a thermocouple can be used as the temperature detection unit. As a result, the control unit 1 can raise the endless belt 23 to a predetermined temperature by controlling the heater based on the temperature detected by the temperature detection unit. Note that a non-contact thermometer using infrared radiation may be used as the temperature detection unit.

[0175] 2.2.4.Printing Department The printing unit 40 is positioned above (towards the +Z axis) the position of the endless belt 23 and prints on the fabric 95 placed on the surface 23a of the endless belt 23. The printing unit 40 includes an inkjet head 42, a carriage 43 on which the inkjet head 42 is mounted, and a carriage movement unit 45 that moves the carriage 43 in the width direction (Y axis direction) of the fabric 95 intersecting the transport direction.

[0176] The inkjet head 42 is a means for spraying and adhering a liquid composition supplied from a liquid cartridge (not shown) onto a fabric 95 from a plurality of nozzles under the control of the control unit 1. The inkjet head 42 is equipped with a plurality of nozzles that eject the liquid composition and adhere it to the fabric 95 to which the liquid composition is to be attached. These plurality of nozzles are arranged in a row to form a nozzle row, and the nozzle row is individually arranged corresponding to the liquid composition. The liquid composition is supplied to the inkjet head 42 from each liquid cartridge and ejected as droplets from the nozzles by actuators (not shown) inside the inkjet head 42. The ejected droplets of liquid composition land on the fabric 95, and images, text, patterns, colors, etc. are formed in the printing area of ​​the fabric 95.

[0177] The liquid compositions referred to here may include the clear ink, white ink, and other inks from the aforementioned ink set. The types and number of these liquid compositions can be set as appropriate.

[0178] In inkjet heads use piezoelectric elements as actuators, which are the driving means, but the method is not limited to this. For example, an electromechanical conversion element that displaces a diaphragm as an actuator by electrostatic attraction, or an electrothermal conversion element that ejects liquid compositions as droplets by generating bubbles through heating may be used.

[0179] Figure 2 is a schematic diagram showing an example of an inkjet head arrangement. In the example in Figure 2, seven inkjet heads 42a to 42g are mounted on the carriage 43, and each of the seven inkjet heads 42a to 42g has two nozzle rows 41.

[0180] In the example shown in Figure 2, for example, the settings can be configured so that no composition is ejected from inkjet head 42a, clear ink is ejected from inkjet head 42b, white ink is ejected from inkjet head 42c, other inks are ejected from inkjet head 42d, and no composition is ejected from inkjet heads 42e, 42f, and 42g.

[0181] The arrangement and number of inkjet heads in the carriage 43 can be changed as appropriate. The time interval between the adhesion of each ink in the inkjet printing recording method of this embodiment can be adjusted, for example, by changing the interval d between the inkjet heads. The time interval between the adhesion of each composition can also be adjusted, for example, by mounting many inkjet heads on the carriage 43 and determining whether or not ink is ejected from each head.

[0182] Each inkjet head can apply each composition to the same area of ​​the fabric at the appropriate timing during a single main scan.

[0183] The carriage movement section 45 is located above the endless belt 23 (on the +Z axis side). The carriage movement section 45 has a pair of guide rails 45a and 45b that extend along the Y axis. The inkjet head 42 is supported by the guide rails 45a and 45b so as to be able to reciprocate along the Y axis together with the carriage 43.

[0184] The carriage movement unit 45 is equipped with a movement mechanism and a power source (not shown). The movement mechanism can include, for example, a mechanism combining a ball screw and a ball nut, or a linear guide mechanism. Furthermore, the carriage movement unit 45 has a motor (not shown) as a power source for moving the carriage 43 along the guide rails 45a and 45b. Various motors can be used as the motor, such as a stepping motor, servo motor, or linear motor. When the motor is driven by the control unit 1, the inkjet head 42 moves along the Y-axis direction together with the carriage 43.

[0185] 2.2.5. Heating Unit A heating unit 27 may be provided between the transport rollers 26 and 28. The heating unit 27 heats the clear ink or white ink dispensed onto the fabric 95. This tends to allow the reaction of the resin particles contained in the ink to proceed sufficiently. By allowing the resin particles to react sufficiently, an image with good friction fastness can be formed. The heating unit 27 may also be used for the purpose of drying the fabric 95. The heating unit 27 may include, for example, an IR heater, and by driving the IR heater, the ink dispensed onto the fabric 95 can be reacted in a short time. This allows the strip-shaped fabric 95 with the image formed on it to be wound onto the winding shaft 31.

[0186] 2.2.6. Washing Unit The cleaning unit 50 is positioned between the belt rotating roller 24 and the belt driving roller 25 in the X-axis direction. The cleaning unit 50 has a cleaning section 51, a pressing section 52, and a moving section 53. The moving section 53 moves the cleaning unit 50 integrally along the floor surface 99 and fixes it in a predetermined position.

[0187] The pressing section 52 is a lifting device composed of, for example, an air cylinder 56 and a ball bush 57, and the cleaning section 51 provided at its upper part comes into contact with the surface 23a of the endless belt 23. The cleaning section 51 is placed between the belt rotating roller 24 and the belt driving roller 25 with a predetermined tension acting on it, and cleans the surface (support surface) 23a of the endless belt 23 as it moves from the belt driving roller 25 toward the belt rotating roller 24 from below (in the -Z axis direction).

[0188] The cleaning unit 51 includes a cleaning tank 54, a cleaning roller 58, and a blade 55. The cleaning tank 54 is a tank for storing a cleaning solution used to clean ink and foreign matter adhering to the surface 23a of the endless belt 23, and the cleaning roller 58 and blade 55 are located inside the cleaning tank 54. As the cleaning solution, for example, water or a water-soluble solvent (such as an aqueous alcohol solution) can be used, and surfactants and defoamers may be added as needed.

[0189] As the cleaning roller 58 rotates, cleaning fluid is supplied to the surface 23a of the endless belt 23, and the cleaning roller 58 and the endless belt 23 slide against each other. This removes ink composition and fibers from the fabric 95 that have adhered to the endless belt 23.

[0190] The blade 55 can be made of a flexible material such as silicone rubber. The blade 55 is located downstream of the cleaning roller 58 in the conveying direction of the endless belt 23. The sliding motion between the endless belt 23 and the blade 55 removes any remaining cleaning liquid from the surface 23a of the endless belt 23.

[0191] With such a recording device 100, the inkjet printing recording method of this embodiment can be easily implemented.

[0192] 2.3. Sequence of processes In the inkjet printing recording method according to this embodiment, the clear ink application step and the white ink application step are performed simultaneously on the same area of ​​the fabric, or the clear ink application step is performed first.

[0193] An embodiment in which the clear ink application process and the white ink application process are performed simultaneously on the same area of ​​the fabric is one in which the clear ink application process and the white ink application process described later are performed on the same area of ​​the fabric in a single scan of the inkjet head. By applying clear ink and white ink to the same area in a single scan, a resin layer is formed near the surface of the fabric, and the friction fastness of the image of the white ink applied on the resin layer can be improved.

[0194] Here, "scanning" refers to moving the inkjet head relative to the recording area on the fabric. In this case, the inkjet head may move relative to the fabric, or the fabric may move relative to the inkjet head. Furthermore, the relative positional relationship between the inkjet head and the fabric may change as both move.

[0195] The inkjet head can be mounted on a carriage, for example. The inkjet head may be moved as the carriage moves; in this case as well, it is the movement of the inkjet head.

[0196] Therefore, "scanning," for example in a serial inkjet recording device, is a process in which recording is performed while a carriage with an inkjet head moves in a scanning direction that intersects the transport direction of the recording medium.

[0197] On the other hand, in line-type inkjet recording devices, "scanning" involves recording being performed while the recording medium moves relative to a line head, which has a length corresponding to the width of the recording medium, in a direction intersecting the width direction. In line-type recording, the inkjet head (line head) remains fixed and does not move during recording, and recording is performed in a single scan.

[0198] The number of times the same scan is performed on the same area of ​​the fabric may be one or more times.

[0199] When the same area of ​​fabric is scanned multiple times, the inkjet head that ejects clear and white ink passes over that area of ​​fabric multiple times. The more times the fabric is scanned, the more evenly the clear and white inks can be applied to the desired area, which tends to improve the image quality of the resulting print.

[0200] In a configuration where the clear ink application process and the white ink application process are performed simultaneously on the same area of ​​the fabric, the difference in application time between the clear ink and the white ink in the same area is preferably within 10 seconds, more preferably within 5 seconds, even more preferably within 1 second, and particularly preferably within 0.05 seconds. When the difference in application time is within the above range, the white ink adheres before the clear ink applied to the fabric penetrates, allowing for good formation of the resin layer. As a result, the resulting friction fastness is good.

[0201] In a configuration where the clear ink application process is performed first on the same area of ​​the fabric, the clear ink application process is performed on the fabric beforehand, and then the white ink application process is performed after it has been left to stand. In this case, the difference in application time between the clear ink and the white ink in the same area is preferably within 10 minutes, more preferably within 5 minutes, even more preferably within 1 minute, and particularly preferably within 10 seconds. Even if the difference in application time is within the above range, the clear ink applied to the fabric does not easily penetrate, so a good resin layer can be formed in the area where the white ink is applied. Therefore, the friction fastness of the resulting layer can be improved.

[0202] 2.4. Effects and Effects According to the inkjet printing recording method of this embodiment, by using a clear ink containing resin particles and making the surface tension of the clear ink 4.5 (mN / m) or more greater than the surface tension of the white ink, the clear ink acts as a base, increasing the adhesion of the white ink to the fabric, thereby enabling the formation of an image with good friction fastness.

[0203] 3. Examples and Comparative Examples The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Hereinafter, "parts" and "%" refer to mass unless otherwise specified. Unless otherwise specified, evaluations were performed in an environment of 25°C and 40.0% relative humidity.

[0204] 3.1. Preparation of each composition Clear ink and white ink were prepared as follows.

[0205] 3.1.1. Preparation of white ink Each component was placed in a container to obtain the composition shown in Table 1. The mixture was then stirred using a magnetic stirrer for 2 hours, and the mixture was filtered through a 5 μm pore size membrane filter to obtain the white inks (W1 to W6) used in the examples and comparative examples. The values ​​in the table represent the solid content.

[0206] 3.1.2. Preparation of clear ink Each component was placed in a container to obtain the composition shown in Table 2. The mixture was then stirred using a magnetic stirrer for 2 hours, and the mixture was filtered through a 5 μm pore size membrane filter to obtain the clear inks (OC1 to OC16) used in the examples and comparative examples. The values ​​in the table represent the solid content.

[0207] The abbreviations and product names shown in Tables 1 to 3 are explained below. • UW-1501F: Manufactured by Ube Industries, Ltd. ETERNACOLL UW series, urethane resin, solid content 30% by mass. • Takerack WS-6021: Product name, manufactured by Mitsui Chemicals, solid content 30% by mass • Takerack WS-6061: Product name, manufactured by Mitsui Chemicals, solid content 30% by mass • Takerack WS-6010: Product name, manufactured by Mitsui Chemicals, solid content 30% by mass Permarin UA-200: Product name, Sanyo Kasei, solid content 30% by mass • Titanium dioxide slurry: Product name "NanoTek(R) Slurry", manufactured by CI Chemicals Co., Ltd., titanium dioxide solids content 20%, average particle size 250nm • Orphine E1010: Acetylene glycol-based surfactant manufactured by Nisshin Chemical Industry Co., Ltd. • BYK-348: Product name, manufactured by BYK, silicone-based surfactant. • Proxel XL2: Preservative and fungicide manufactured by Lonza Japan Co., Ltd. • Meikanate TP-10: Manufactured by Meisei Chemical Industry Co., Ltd., blocked isocyanate (TDI-based anionic) • Carbodilite E-02: Manufactured by Nisshinbo Chemical, carbodiimide • Epocross K2010E: Manufactured by Nippon Shokubai Co., Ltd., contains oxazoline groups. • Orphine D-10: Acetylene glycol-based surfactant manufactured by Nisshin Chemical Industry Co., Ltd. • EXP4300: Acetylene glycol-based surfactant manufactured by Nisshin Chemical Industry Co., Ltd.

[0208] 3.1.3. 100% Modulus Tables 1 to 3 show the 100% modulus values ​​of the resin particles used. The 100% modulus of the resin particles was determined by heating the resin particles at 170°C for 5 minutes to create a film with a thickness of approximately 60 μm, and then measuring the tensile stress when the film was stretched to 100% of its original length in a tensile test conducted under conditions of a tensile test gauge length of 20 mm and a tensile speed of 100 mm / min.

[0209] 3.1.4.Surface tension Tables 1 to 3 show the surface tension of each white ink and each clear ink. Surface tension was measured using the Wilhelmy method (plate method) with a Kyowa Interface Chemical Co., Ltd. DY-300 surface tensimeter at 25°C.

[0210] 3.2. Preparation of Printed Materials For the printing record, a modified Evo Tre 16 (manufactured by Seiko Epson Corporation) was used. 100% cotton white broadcloth was used as the recording medium. A head unit (600 dpi nozzle spacing in the recording medium width direction, 600 nozzles) was used. The recording conditions were a recording resolution of 1200 dpi × 600 dpi and a print density of 27.6 g / m². 2 (100% duty cycle) was assumed, and the droplet mass was set to 24.7 ng / dot.

[0211] A solid pattern image was formed on an A3-sized piece of fabric as the recording medium, and a printed product was manufactured. Here, a "solid pattern image" refers to an image in which dots are recorded for all pixels, which are the smallest recording unit area defined by the recording resolution. The printed product was then heat-treated in an oven at 160°C for 3 minutes and dried.

[0212] In Examples 1-16 and Comparative Examples 1-4, clear ink (OC) and white ink (W) were recorded in the same pass in that order, with a time difference of 55 ms between impacts on the fabric. In Examples 17 and 18, clear ink (OC) was applied first, with time differences of 300,000 ms (5 min) and 180,000 ms (3 min), respectively, between impacts on the fabric.

[0213] Table 4 lists the types of white ink (W) and clear ink (OC) used in each example, their respective surface tensions, and the difference in surface tension (clear ink (OC) - white ink (W)).

[0214] 3.3. Evaluation Method 3.3.1. Evaluation of abrasion resistance For each example of the printing cloth, the abrasion resistance was tested using a test method compliant with ISO 105-X12, and the degree of peeling at the interface between the cloth and the printing area was evaluated according to the following criteria. The results are shown in Table 4. A: The area of ​​peeling on the abrasion-resistant surface is less than 5%. B: The area of ​​peeling on the abrasion-resistant surface is 5% or more but less than 25%. C: The area of ​​the abrasion-resistant surface that has peeled off is between 25% and 50%. D: More than 50% of the surface is peeling off due to friction.

[0215] 3.3.2. Evaluation of the texture of printed fabrics The texture of the printed fabrics in each example was evaluated by sensory evaluation. Specifically, five randomly selected judges were asked to respond with either "It is comparable to the original feel of the fabric" or "The printed fabric is stiff and the original feel of the fabric is compromised," and they evaluated the fabrics according to the following criteria. The results are shown in Table 4. A: Five judges responded that the fabric had "no inferiority to its original texture." B: Three to five judges responded that the fabric had "no inferior feel to the original fabric." C: One to three judges responded that the fabric had "no inferiority to its original texture." D: Zero judges responded that the fabric's texture was "indistinguishable from the original fabric's texture."

[0216] 3.4. Evaluation Results Table 4 shows that in each example, the ink set in which the clear ink contained first resin particles, a crosslinking agent, and water, with the content of first resin particles being 4.5% by mass or more relative to the total amount of clear ink, and the white ink contained white pigment, second resin particles, and water, and the surface tension of the clear ink was 4.5 (mN / m) or more greater than the surface tension of the white ink, good abrasion resistance (friction fastness) was obtained.

[0217] The present invention includes configurations substantially identical to those described in the embodiments, for example, configurations with the same function, method, and results, or configurations with the same purpose and effect. Furthermore, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as those described in the embodiments. Finally, the present invention includes configurations that add known technology to the configurations described in the embodiments.

[0218] The following can be derived from the embodiments and modifications described above.

[0219] The ink set is An ink set comprising a clear ink which is a textile inkjet composition and a white ink which is a textile inkjet composition, The clear ink contains first resin particles, a crosslinking agent, and water. The content of the first resin particles is 4.5% by mass or more relative to the total amount of the clear ink. The aforementioned white ink contains a white pigment, second resin particles, and water. The surface tension of the clear ink is at least 4.5 mN / m greater than the surface tension of the white ink.

[0220] According to this ink set, by using a clear ink containing resin particles and making the surface tension of the clear ink at least 4.5 mN / m greater than that of the white ink, the clear ink acts as a base, increasing the adhesion of the white ink to the fabric, thus enabling the formation of images with good friction fastness.

[0221] In the above ink set, The aforementioned white pigment may be a titanium dioxide pigment.

[0222] This ink set allows you to obtain images with better color reproduction.

[0223] In the above ink set, The content of the first resin particles may be 80% by mass or more relative to the total amount of colorant and resin in the clear ink.

[0224] With this ink set, since the clear ink contains virtually no colorants, the coloring caused by the colorants in the clear ink is reduced, and the tonal changes of the image due to the white ink are less likely to occur. In addition, the resin content in the clear ink is increased, which improves the friction fastness of the resulting image.

[0225] In the above ink set, The amount of the crosslinking agent may be 0.5% by mass or more relative to the total amount of the clear ink.

[0226] This ink set allows for better friction fastness of the resulting images.

[0227] In the above ink set, The crosslinking agent may contain one or more compounds selected from blocked isocyanate compounds, carbodiimide compounds, and oxazoline compounds.

[0228] This ink set allows for better friction fastness of the resulting images.

[0229] In the above ink set, The 100% modulus of the first resin particles may be 10 MPa or higher.

[0230] According to this ink set, the first resin particles contained in the clear ink are harder, which can improve the frictional fastness of the resulting image.

[0231] In the above ink set, The 100% modulus of the second resin particles may be 6 MPa or less.

[0232] According to this ink set, the second resin particles in the white ink are softer, resulting in a better texture for printed materials. Furthermore, even when a large amount of white ink is applied, it is easier to achieve a good texture for the printed material.

[0233] In the above ink set, The 100% modulus of the first resin particles may be greater than the 100% modulus of the second resin particles.

[0234] This ink set allows for an even better balance between the friction fastness of the resulting image and the texture of the printed material.

[0235] The inkjet printing recording method is, An inkjet printing recording method using a clear ink, which is a textile printing inkjet composition, and a white ink, which is a textile printing inkjet composition, The clear ink is ejected by an inkjet method and attached to the fabric in a clear ink application process, The process includes a step of applying white ink, in which the white ink is ejected by an inkjet method and adhered to the fabric. The clear ink contains first resin particles, a crosslinking agent, and water. The content of the first resin particles is 4.5% by mass or more relative to the total amount of the clear ink. The aforementioned white ink contains a white pigment, second resin particles, and water. The surface tension of the clear ink is 4.5 mN / m or more greater than the surface tension of the white ink. The clear ink application step and the white ink application step are performed simultaneously on the same area of ​​the fabric, or the clear ink application step is performed first.

[0236] According to this inkjet printing recording method, by using a clear ink containing resin particles and making the surface tension of the clear ink at least 4.5 mN / m greater than that of the white ink, the clear ink acts as a base, increasing the adhesion of the white ink to the fabric, thus enabling the formation of an image with good friction fastness. [Explanation of Symbols]

[0237] 1...Control unit, 10...Media supply unit, 11...Supply shaft unit, 12...Bearing unit, 20...Media transport unit, 21...Transport roller, 22...Transport roller, 23...Endless belt, 23a...Surface, 23b...Inner surface, 24...Belt rotating roller, 25...Belt drive roller, 26...Transport roller, 27...Heating unit, 28...Transport roller, 29...Adhesive, 30...Media recovery unit, 31...Winding shaft unit, 32...Bearing unit, 40...Printing unit, 41...Nozzle row, 42a~42g...Inkjet Jet head, 43...carriage, 45...carriage movement section, 45a...guide rail, 45b...guide rail, 46...platen, 50...washing unit, 51...washing section, 52...pressing section, 53...moving section, 54...washing tank, 55...blade, 56...air cylinder, 57...ball bush, 58...washing roller, 60...media contact section, 61...pressing section, 69...contact section, 90...frame section, 91...belt support section, 95...fabric, 99...floor surface, 100...recording device

Claims

1. An ink set comprising a clear ink which is a textile inkjet composition and a white ink which is a textile inkjet composition, The clear ink contains first resin particles, a crosslinking agent, and water. The content of the first resin particles is 4.5% by mass or more relative to the total amount of the clear ink. The aforementioned white ink contains a white pigment, second resin particles, and water. The surface tension of the clear ink is 4.5 mN / m or greater than the surface tension of the white ink. Ink set.

2. In claim 1, An ink set in which the aforementioned white pigment is titanium dioxide pigment.

3. In claim 1, An ink set in which the content of the first resin particles is 80% by mass or more relative to the total amount of colorant and resin in the clear ink.

4. In claim 1, An ink set in which the crosslinking agent content is 0.5% by mass or more relative to the total amount of the clear ink.

5. In claim 1, An ink set wherein the crosslinking agent contains one or more selected from blocked isocyanate compounds, carbodiimide compounds, and oxazoline compounds.

6. In claim 1, An ink set in which the 100% modulus of the first resin particles is 10 MPa or higher.

7. In claim 1, An ink set in which the 100% modulus of the second resin particles is 6 MPa or less.

8. In claim 1, An ink set in which the 100% modulus of the first resin particles is greater than the 100% modulus of the second resin particles.

9. An inkjet printing recording method using a clear ink, which is a textile printing inkjet composition, and a white ink, which is a textile printing inkjet composition, The clear ink is ejected by an inkjet method and attached to the fabric in a clear ink application process, The process includes a step of applying white ink, in which the white ink is ejected by an inkjet method and adhered to the fabric. The clear ink contains first resin particles, a crosslinking agent, and water. The content of the first resin particles is 4.5% by mass or more relative to the total amount of the clear ink. The aforementioned white ink contains a white pigment, second resin particles, and water. The surface tension of the clear ink is 4.5 mN / m or more greater than the surface tension of the white ink. An inkjet printing recording method wherein the clear ink application step and the white ink application step are performed simultaneously on the same area of ​​the fabric, or the clear ink application step is performed first.

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