Ink composition for inkjet printing

Abstract

To provide an ink composition for inkjet printing, which has a good leveling property even when printed on a low-absorptive substrate and a non-absorptive substrate and which exhibits, when a solid image is printed, a good solid fill.SOLUTION: Provided is an ink composition for inkjet printing, comprising a color material (A), an anionic group-containing resin (B), a water-soluble organic solvent (C), resin fine particles (D), a surfactant (E) and water (F), where the surfactant (E) comprises: one or more nonionic surfactants (E-1) selected from the group consisting of acetylene-based surfactants and silicone-based surfactants; a nonionic surfactant (E-2) other than (E-1); and 2,4,7,9-tetramethyl-4,7-decanediol (E-3), where the nonionic surfactant (E-2) is one or more nonionic surfactants selected from the group consisting of polyoxyalkylene group-containing fatty acid glyceryls containing a plurality of polyoxyalkylene groups in the molecule and having an HLB value of 10 or more and less than 15.5, polyoxyalkylene group-containing aliphatic amines and polyoxyalkylene group-containing sorbitan fatty acid esters, and a total amount of the nonionic surfactant (E-2) and the 2,4,7,9-tetramethyl-4,7-decanediol (E-3) is 3.8 mass% or less in the ink composition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an ink composition for ink-jet printing. More specifically, the present invention relates to an ink composition for ink-jet printing that has good leveling properties even on low-absorbency substrates and non-absorbent recording media. [Background technology]

[0002] Conventionally, aqueous inkjet inks for printing on various substrates have been developed. However, when the aqueous inkjet ink is printed on a low-absorbency substrate or a non-absorbency substrate, the leveling property is poor unless a primer is applied in advance, and when a solid image is printed, the solid filling is low.

[0003] In view of this, as an aqueous inkjet ink for low-absorbency substrates, an aqueous inkjet ink containing a polyoxyalkylene alkyl ether type surfactant and an acetylene glycol type surfactant has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-80430 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the water-based inkjet ink described in Patent Document 1 has poor leveling properties, and when a solid image is printed, the solid filling is low and insufficient.

[0006] The present invention has been made in consideration of such conventional problems, and has an object to provide an ink composition for inkjet printing which has good leveling properties even when printed on a low-absorbency substrate or a non-absorbency substrate, and which also has good solid filling when a solid image is printed. [Means for solving the problem]

[0007] The present inventors conducted extensive research to solve the above problems, and as a result, discovered that the above problems could be solved by employing a specific combination of surfactants, thereby completing the present invention. The ink composition for ink-jet printing of the present invention, which solves the above problems, mainly comprises the following components.

[0008] (1) A composition comprising a colorant (A), an anionic group-containing resin (B), a water-soluble organic solvent (C), resin particles (D), a surfactant (E), and water (F), wherein the surfactant (E) comprises one or more nonionic surfactants (E-1) selected from the group consisting of acetylene-based surfactants and silicone-based surfactants, a nonionic surfactant (E-2) other than the nonionic surfactant (E-1), and 2,4,7,9-tetramethyl-4,7-decanediol (E-3), wherein the nonionic surfactant (E-2) is one or more nonionic surfactants selected from the group consisting of polyoxyalkylene group-containing fatty acid glyceryls, polyoxyalkylene group-containing aliphatic amines, and polyoxyalkylene group-containing sorbitan fatty acid esters having a plurality of polyoxyalkylene groups in the molecule and an HLB value of 10 or more and less than 15.5, The ink composition for ink-jet printing, wherein the total amount of the nonionic surfactant (E-2) and 2,4,7,9-tetramethyl-4,7-decanediol (E-3) is 3.8 mass % or less in the ink composition.

[0009] According to this configuration, the ink composition for inkjet printing has good leveling properties even when printed on a low-absorbency substrate or a non-absorbency substrate, and when a solid image is printed, the solid filling is also good.

[0010] (2) The ink composition for ink-jet printing according to (1), wherein the water-soluble organic solvent (C) contains an organic solvent having a boiling point of 120 to 200°C.

[0011] According to this configuration, the ink composition for ink-jet printing can be dried with lower thermal energy than before, a good printed matter can be obtained, and further, the storage stability is excellent.

[0012] (3) The ink composition for ink-jet printing according to (1) or (2), wherein the resin fine particles (D) contain at least one of a wax and an emulsion.

[0013] According to this configuration, the ink composition for ink-jet printing has excellent drying properties and abrasion resistance. Effect of the Invention

[0014] According to the present invention, it is possible to provide an ink composition for inkjet printing that has good leveling properties even when printed on a low-absorbency substrate or a non-absorbency substrate, and also has good solid filling when a solid image is printed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] <Ink composition for inkjet printing> An ink composition for inkjet printing (hereinafter also referred to as ink composition) according to one embodiment of the present invention contains a colorant (A), an anionic group-containing resin (B), a water-soluble organic solvent (C), resin particles (D), a surfactant (E), and water (F). The surfactant (E) contains one or more nonionic surfactants (E-1) selected from the group consisting of acetylene-based surfactants and silicone-based surfactants, a nonionic surfactant (E-2) other than the nonionic surfactant (E-1), and 2,4,7,9-tetramethyl-4,7-decanediol (E-3). The nonionic surfactant (E-2) is one or more nonionic surfactants selected from the group consisting of polyoxyalkylene group-containing fatty acid glyceryls, polyoxyalkylene group-containing aliphatic amines, and polyoxyalkylene group-containing sorbitan fatty acid esters, each of which has a plurality of polyoxyalkylene groups in its molecule and has an HLB value of 10 or more and less than 15.5. The total amount of the nonionic surfactant (E-2) and 2,4,7,9-tetramethyl-4,7-decanediol (E-3) in the ink composition is 3.8% by mass or less. Each of them will be described below.

[0016] (Colorant (A)) The ink composition of the present embodiment contains a coloring material (pigment). There are no particular limitations on the pigment. For example, the pigment may be any of various organic pigments and inorganic pigments.

[0017] Examples of organic pigments include dye lake pigments, azo-based, benzimidazolone-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigo-based, thioindigo-based, perylene-based, perinone-based, diketopyrrolopyrrole-based, isoindolinone-based, nitro-based, nitroso-based, flavanthrone-based, quinophthalone-based, pyranthrone-based, and indanthrone-based pigments.

[0018] Inorganic pigments include colored pigments such as titanium oxide, red ocher, antimony red, cadmium yellow, cobalt blue, ultramarine, Prussian blue, iron black, chromium oxide green, carbon black, and graphite (including achromatic colored pigments such as white and black), as well as extender pigments such as calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc.

[0019] Representative specific examples of pigments for each hue of the ink composition of this embodiment are as follows.

[0020] The yellow pigment is CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 42, 73, 74, 75, 81, 83, 87, 93, 95, 97, 98, 108, 109, 114, 120, 128, 129, 138, 139, 150, 151, 155, 166, 180, 184, 185, 213, etc., and preferably CI Pigment Yellow 150, 155, 180, 213, etc.

[0021] Magenta pigments include CI Pigment Red 5, 7, 12, 19, 22, 38, 48:1, 48:2, 48:4, 49:1, 53:1, 57, 57:1, 63:1, 101, 102, 112, 122, 123, 144, 146, 149, 168, 177, 178, 179, 180, 184, 185, 190, 202, 209, 224, 242, 254, 255, 270, CI Pigment Violet 19, and the like, and preferably CI Pigment Red 122, 202, Pigment Violet 19, and the like.

[0022] Cyan pigments include CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 18, 22, 27, 29, 60, etc., and preferably CI Pigment Blue 15:4, etc.

[0023] The black pigment is carbon black (CI Pigment Black 7) or the like.

[0024] The white pigment is titanium oxide, aluminum oxide, or the like, and is preferably titanium oxide or the like that has been surface-treated with various materials such as alumina or silica.

[0025] The content of the pigment is not particularly limited. For example, the content of the pigment other than white is preferably 0.5% by mass or more, more preferably 2% by mass or more, in the ink composition. The content of the pigment other than white is preferably 10% by mass or less, more preferably 8% by mass or less, in the ink composition. On the other hand, the content of the white pigment is preferably 4% by mass or more, more preferably 8% by mass or more, in the ink composition. The content of the white pigment is preferably 25% by mass or less, more preferably 20% by mass or less, in the ink composition. When the content of the pigment is within the above range, the ink composition has excellent color reproducibility.

[0026] The pigment may be coated with an anionic group-containing resin (B) described below.

[0027] (Anionic Group-Containing Resin (B)) The anionic group-containing resin is an alkali-soluble resin that can be used for dispersing pigments or as a binder in ordinary inks and paints, and is not particularly limited as long as it can be dissolved in an aqueous medium in the presence of a basic compound. The anionic group-containing resin is preferably a resin that contains one or more types of anionic groups such as a carboxyl group, a sulfonic acid group, or a phosphonic acid group.

[0028] The anionic group-containing resin preferably further has a hydrophobic portion in the molecule, which is mainly for improving the adsorption to the pigment, and / or a hydrophilic portion in the molecule, which is mainly for obtaining an effective action for preventing aggregation in an aqueous medium. Examples of the hydrophobic portion to be introduced into the molecule include hydrophobic groups such as long-chain alkyl groups and alicyclic or aromatic cyclic hydrocarbon groups. Examples of the hydrophilic portion to be introduced into the molecule include hydrophilic groups such as (poly)oxyalkylene chains, basic nitrogen-containing groups, hydroxyl groups, and epoxy groups.

[0029] From the viewpoint of enhancing the dispersion stability of the pigment, the acid value of the anionic group-containing resin is preferably 50 mgKOH / g or more, more preferably 60 mgKOH / g or more, and even more preferably 70 mgKOH / g or more. From the viewpoint of enhancing the water resistance of the printed matter, the acid value of the anionic group-containing resin is preferably 350 mgKOH / g or less, and more preferably 300 mgKOH / g or less. The acid value is a theoretical acid value calculated arithmetically from the mg of potassium hydroxide theoretically required to neutralize 1 g of the anionic group-containing resin based on the composition of the monomers used to synthesize the anionic group-containing resin.

[0030] The weight average molecular weight of the anionic group-containing resin is preferably 3,000 or more, more preferably 7,000 or more, from the viewpoint of enhancing the dispersion stability of the pigment. The weight average molecular weight of the anionic group-containing resin is preferably 200,000 or less, more preferably 100,000 or less, from the viewpoint of enhancing the solubility in an aqueous medium described later. The weight average molecular weight can be measured by gel permeation chromatography (GPC). As an example, chromatography is performed using a Water2690 (manufactured by Waters) as a GPC device and a PLgel, 5μ, MIXED-D (manufactured by Polymer Laboratories) as a column under the conditions of tetrahydrofuran as a developing solvent, a column temperature of 25°C, a flow rate of 1 milliliter / minute, an RI detector, a sample injection concentration of 10 milligrams / milliliter, and an injection amount of 100 microliters, and the weight average molecular weight can be calculated as a polystyrene-equivalent weight average molecular weight.

[0031] Examples of the anionic group-containing resin include acrylic copolymer resins, maleic acid copolymer resins, polyester resins obtained by condensation polymerization, and polyurethane resins. Materials for synthesizing such anionic group-containing resins are disclosed in, for example, JP-A-2000-94825, and acrylic copolymer resins, maleic acid copolymer resins, polyester resins, polyurethane resins, and the like obtained using materials described in the publication can be used. Furthermore, the anionic group-containing resin can of course also be a resin obtained using other materials. At least one type of anionic group-containing resin may be used, and two or more types may be used in combination.

[0032] The acrylic copolymer resin can be obtained by polymerizing a mixture of an anionic group-containing monomer and another copolymerizable monomer in a solvent in the presence of a conventional radical generator (e.g., benzoyl peroxide, tertiary butyl peroxybenzoate, azobisisobutyronitrile, etc.).

[0033] The anionic group-containing monomer may be a monomer having at least one anionic group selected from the group consisting of a carboxyl group, a sulfonic acid group, and a phosphonic acid group, and among these, a monomer having a carboxyl group is preferred.

[0034] Examples of monomers having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, 2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, maleic anhydride, fumaric anhydride, and maleic acid half ester. Examples of monomers having a sulfonic acid group include sulfoethyl methacrylate. Examples of monomers having a phosphonic acid group include phosphonoethyl methacrylate.

[0035] From the viewpoint of improving the adsorptivity to the pigment, the other monomer copolymerizable with the anionic group-containing monomer preferably contains a hydrophobic group-containing monomer.

[0036] Examples of the hydrophobic group-containing monomer include monomers having a long-chain alkyl group, such as alkyl esters of radically polymerizable unsaturated carboxylic acids having 8 or more carbon atoms, such as (meth)acrylic acid (e.g., 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxystearyl (meth)acrylate, etc.), alkyl vinyl ethers having 8 or more carbon atoms (e.g., dodecyl vinyl ether, etc.), and vinyl esters of fatty acids having 8 or more carbon atoms (e.g., vinyl 2-ethylhexanoate, vinyl laurate, vinyl stearate, etc.); monomers having an alicyclic hydrocarbon group, such as cyclohexyl (meth)acrylate; and monomers having an aromatic hydrocarbon group, such as styrene-based monomers, such as benzyl (meth)acrylate, styrene, α-styrene, and vinyl toluene.

[0037] The other monomer copolymerizable with the anionic group-containing monomer preferably contains a hydrophilic group-containing monomer from the viewpoint of suppressing aggregation of the anionic group-containing resin in an aqueous medium described below.

[0038] Examples of the hydrophilic group-containing monomer include monomers having a (poly)oxyalkylene chain, such as esters of one-end alkyl-blocked (poly)alkylene glycols, such as methoxypolyethylene glycol, methoxypolyethylenepolypropylene glycol, ethoxypolyethylene glycol, ethoxypolyethylenepolypropylene glycol, propoxypolyethylene glycol, and propoxypolyethylenepolypropylene glycol, with radically polymerizable unsaturated carboxylic acids, such as (meth)acrylic acid, and ethylene oxide and / or propylene oxide adducts of radically polymerizable unsaturated carboxylic acids, such as (meth)acrylic acid; and examples of the basic group-containing monomers include vinylpyrrolidones, such as 1-vinyl-2-pyrrolidone and 1-vinyl-3-pyrrolidone, vinylpyridines, such as 2-vinylpyridine, 4-vinylpyridine, 5-methyl-2-vinylpyridine, and 5-ethyl-2-vinylpyridine, 1-vinyl Examples of suitable monomers include vinyl imidazoles such as imidazole and 1-vinyl-2-methylimidazole, vinyl piperidines such as 3-vinylpiperidine and N-methyl-3-vinylpiperidine, nitrogen-containing derivatives of (meth)acrylic acid such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, tert-butylaminoethyl (meth)acrylate, (meth)acrylamide, N-methylol (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-methoxy (meth)acrylamide, N-ethoxy (meth)acrylamide, N-dimethylacrylamide, and N-propylacrylamide; monomers having a hydroxyl group include hydroxyalkyl esters of (meth)acrylic acid such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate; and monomers having an epoxy group include, for example, glycidyl (meth)acrylate.

[0039] Examples of copolymerizable monomers other than the hydrophobic group-containing monomer and the hydrophilic group-containing monomer include alkyl esters of (meth)acrylic acid having less than 8 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, and hexyl (meth)acrylate.

[0040] The amount of the anionic group-containing resin used is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, relative to 100 parts by mass of the pigment, from the viewpoint of increasing the dispersion stability of the pigment. The amount of the anionic group-containing resin used is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, relative to 100 parts by mass of the pigment, from the viewpoint of decreasing the viscosity of the ink composition.

[0041] (Basic compounds) From the viewpoint of dissolving the anionic group-containing resin, the ink composition of the present embodiment preferably contains a basic compound. The basic compound is an inorganic basic compound such as sodium hydroxide or potassium hydroxide, or an organic basic compound such as ammonia, methylamine, ethylamine, monoethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, diethanolamine, N-methyldiethanolamine, triethanolamine, morpholine, N-methylmorpholine, or N-ethylmorpholine.

[0042] The content of the basic compound may be an amount that dissolves the anionic group-containing resin in the medium, and is usually preferably 0.05% by mass or more, more preferably 0.1% by mass or more, in the ink composition from the viewpoint of improving the dispersion stability of the anionic group-containing resin. Also, the content of the basic compound is preferably 1% by mass or less, more preferably 0.5% by mass or less, in the viewpoint of improving the water resistance of the printed matter.

[0043] (Water-soluble organic solvent (C)) The water-soluble organic solvent is blended to improve the uniformity of the coating film obtained when an inkjet image is formed, and to dissolve any water-insoluble component. The ink composition of the present embodiment preferably contains at least one water-soluble organic solvent having a boiling point selected from the range of 120 to 200°C.

[0044] The water-soluble organic solvent having a boiling point of 120 to 200° C. preferably contains at least one of glycols, glycol ethers, and methoxybutanols.

[0045] There is no particular limitation on the glycols having a boiling point of 120 to 200° C. Examples of glycols having a boiling point of 120 to 200° C. include ethylene glycol and propylene glycol.

[0046] There is no particular limitation on glycol ethers having a boiling point of 120 to 200° C. Examples of glycol ethers having a boiling point of 120 to 200° C. include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monopropyl ether, and ethylene glycol tertiary butyl ether.

[0047] There is no particular limitation on the methoxybutanols having a boiling point of 120 to 200° C. Examples of methoxybutanols having a boiling point of 120 to 200° C. include 3-methoxy-1-butanol and 3-methoxy-3-methylbutanol.

[0048] By including at least one water-soluble organic solvent having a boiling point selected from the range of 120 to 200° C., the ink composition can achieve both coating drying properties and ejection stability without impairing storage stability.

[0049] Returning to the description of the water-soluble organic solvent as a whole, the water-soluble organic solvent of the present embodiment may include other water-soluble organic solvents in addition to the water-soluble organic solvents described above. The other water-soluble organic solvents are not particularly limited. Examples of the other water-soluble organic solvents include methanol, ethanol, propanol, butanol, hexanol, glycerin, polyglycerin, acetone, acetonitrile, isopropanol, and tetrahydrofuran.

[0050] The total amount of the water-soluble organic solvents having a boiling point of 120 to 200° C. may be 90% by mass or more, preferably 95% by mass or more, and more preferably 98% by mass or more, in the water-soluble organic solvent. By having the total amount of the water-soluble organic solvents having a boiling point of 120 to 200° C. be 90% by mass or more, the ink composition has excellent drying properties and is less likely to bleed in the resulting inkjet image.

[0051] (Resin fine particles (D)) The resin fine particles are blended to impart coating film drying properties and abrasion resistance. The resin fine particles are prepared by dispersing a resin that is poorly soluble or insoluble in the solvent (aqueous medium) of the ink composition of this embodiment in the form of fine particles.

[0052] The resin particles are not particularly limited. For example, the resin particles may be wax, emulsion (urethane resin particles, styrene acrylic resin particles, acrylic resin particles, polyolefin resin particles, vinyl acetate resin particles, vinyl chloride resin particles, silicone resin particles, fluororesin particles, polyether-based resin particles, polyester-based resin particles, polycarbodiimide resin particles), colloidal silica, etc. Among these, the ink composition of the present embodiment preferably contains at least one of wax and emulsion as the resin particles. This provides the ink composition with excellent drying properties and abrasion resistance.

[0053] When the resin fine particles are wax, the wax is not particularly limited, and examples of the wax include various natural waxes and synthetic waxes.

[0054] Natural waxes include petroleum-based waxes such as paraffin wax and microcrystalline wax; lignite-based waxes such as montan wax; vegetable waxes such as carnauba wax and candelilla wax; and animal and vegetable waxes such as beeswax and lanolin, etc., dispersed in an aqueous medium.

[0055] The synthetic wax is a polyalkylene wax (preferably a poly C2-C4 alkylene wax), an oxidized polyalkylene wax (preferably a poly C2-C4 alkylene wax), etc. Among these, the synthetic wax is preferably a polyethylene wax, a polypropylene wax, an oxidized polyethylene wax, an oxidized polypropylene wax, etc., and more preferably an oxidized polyethylene wax.

[0056] The wax may be a commercially available product, such as CERAFLOUR 925, 929, 950, 991, AQUACER 498, 515, 526, 531, 537, 539, 552, 1547, AQUAMAT 208, 263, 272, MINERPOL 221, etc., manufactured by BYK-Chemie Co., Ltd., Mitsui Hiwax NL100, NL200, NL500, 4202E, 1105A, 2203A, NP550, NP055, NP505, etc., manufactured by Mitsui Chemicals, Inc., and KUE-100 and 11, etc., manufactured by Sanyo Chemical Co., Ltd. Among these, the resin fine particles which are wax are preferably AQUACER 515, 531, 537, 539, and 1547, and more preferably AQUACER 515, 531, 537, and 1547.

[0057] The resin fine particles that are emulsions are not particularly limited. For example, the resin fine particles that are emulsions include homopolymers or copolymers of (meth)acrylic acid, (meth)acrylic acid esters, acrylonitrile, cyanoacrylate, acrylamide, olefin, styrene, vinyl acetate, vinyl chloride, vinyl alcohol, vinyl ether, vinyl pyrrolidone, vinyl pyridine, vinyl carbazole, vinyl imidazole, and vinylidene chloride, fluororesins, and natural resins. Among these, the resin fine particles are preferably acrylic resins that are homopolymers or copolymers of at least one of (meth)acrylic monomers such as (meth)acrylic acid, (meth)acrylic acid esters, acrylonitrile, and cyanoacrylate. In addition, the acrylic resin is preferably a copolymer of a (meth)acrylic monomer and a vinyl monomer. The vinyl monomer includes styrene, and a styrene-acrylic copolymer resin that is a copolymer of a (meth)acrylic monomer and styrene is preferable. The above-mentioned copolymer may be in any form of a random copolymer, a block copolymer, an alternating copolymer, or a graft copolymer. In addition, the resin fine particles that are an emulsion may be polyurethane-based resin, polyester-based resin, polyether-based resin, or the like.

[0058] The method of preparing the emulsion is not particularly limited. For example, the resin microparticles can be obtained by a method of mixing a polymerization catalyst (polymerization initiator) and a dispersant in a monomer constituting a desired resin and polymerizing (i.e., emulsion polymerization), a method of dissolving a resin having a hydrophilic portion in a water-soluble organic solvent, mixing the solution in water, and then removing the water-soluble organic solvent by distillation or the like, or a method of dissolving a resin in a water-insoluble organic solvent and mixing the solution together with a dispersant in an aqueous solution. The dispersant that can be used when dispersing the resin is not particularly limited. For example, the dispersant is an anionic surfactant (sodium dodecylbenzenesulfonate, sodium lauryl phosphate, polyoxyethylene alkyl ether sulfate ammonium salt, etc.), or a nonionic surfactant (polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, etc.).

[0059] The resin microparticles in the form of an emulsion may be commercially available products, such as Microgel E-1002, Microgel E-5002 (manufactured by Nippon Paint Co., Ltd.), Boncoat 4001, Boncoat 5454 (manufactured by DIC Corporation), SAE1014 (manufactured by Zeon Corporation), Cybinol SK-200 (manufactured by Saiden Chemical Co., Ltd.), Julimer AT-613 (manufactured by Toa Gosei Co., Ltd.), Vinyblan 700 (manufactured by Nissin Chemical Industry Co., Ltd.), Joncryl 7100, Joncryl 390, Joncryl 711, Joncryl 511, Joncryl 7001, Joncryl 632, Joncryl 741, Joncryl 450, Examples of such resins include JONCRYL 840, JONCRYL 74J, JONCRYL HRC-1645J, JONCRYL 734, JONCRYL 852, JONCRYL 7600, JONCRYL 775, JONCRYL 537J, JONCRYL 1535, JONCRYL PDX-7630A, JONCRYL 352J, JONCRYL 352D, JONCRYL PDX-7145, JONCRYL 538J, JONCRYL 7640, JONCRYL 7641, JONCRYL 631, JONCRYL 790, JONCRYL 780, and JONCRYL 7610 (manufactured by BASF Japan Ltd.).

[0060] The resin microparticles may contain a composite resin. The composite resin is composed of two or more resins that are different from each other in the composition (at least one of the type and the content ratio) of the monomer components that compose the resin as a fixing agent, and it does not matter which part of the resin microparticles these two or more resins compose. When a core-shell resin is used, in which one of the two or more resins is a core resin and the other is a shell resin, the core resin is a resin that mainly composes the center part of the resin microparticle, and the shell resin is a resin that mainly composes the peripheral part of the resin microparticle, it is preferable in that the resin properties can be changed between the peripheral part and the central part of the resin. It is sufficient that the shell resin composes at least a part of the peripheral part of the resin microparticle.

[0061] Returning to the explanation of the resin microparticles as a whole, the average particle diameter (volume average particle diameter) of the resin microparticles, which are wax and emulsion, is not particularly limited. For example, the average particle diameter is preferably 5 nm or more, more preferably 50 nm or more, from the viewpoint of excellent storage stability and ejection reliability of the ink composition. Moreover, the average particle diameter is preferably 400 nm or less, more preferably 200 nm or less. Furthermore, by having the average particle diameter of the resin microparticles within the above range, the ink composition has excellent film-forming properties, is less likely to cause aggregation, and is less likely to cause clogging. The method for measuring the volume average particle diameter is not particularly limited. For example, the measurement method can be performed using a particle size distribution measuring device that uses the dynamic light scattering theory as the measurement principle. An example of such a particle size distribution measuring device is "Microtrack UPA" manufactured by Nikkiso Co., Ltd.

[0062] The glass transition temperature (Tg) of the resin fine particles is preferably −20° C. or higher, and more preferably −10° C. or higher. Furthermore, Tg is preferably 100° C. or lower, and more preferably 80° C. or lower. When the Tg of the resin fine particles is within the above range, the ink composition can impart coating drying properties and abrasion resistance.

[0063] The content of the resin microparticles (converted into solid content) is not particularly limited. As an example, the content of the resin microparticles in the ink composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 2% by mass or more. The content of the resin microparticles in the ink composition is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less. When the content of the resin microparticles is within the above range, the ink composition has excellent ejection stability. In addition, the ink composition is likely to form an image having excellent water resistance and abrasion resistance.

[0064] (Surfactant (E)) The ink composition of this embodiment contains, as a surfactant, one or more nonionic surfactants (E-1) selected from the group consisting of acetylene-based surfactants and silicone-based surfactants, a nonionic surfactant (E-2) other than the surfactant (E-1), and 2,4,7,9-tetramethyl-4,7-decanediol (E-3). The nonionic surfactant (E-2) is one or more nonionic surfactants selected from the group consisting of polyoxyalkylene group-containing fatty acid glyceryls, polyoxyalkylene group-containing aliphatic amines, and polyoxyalkylene group-containing sorbitan fatty acid esters, each of which has a plurality of polyoxyalkylene groups in its molecule and has an HLB value of 10 or more and less than 15.5.

[0065] One or more nonionic surfactants selected from the group consisting of acetylene-based surfactants and silicone-based surfactants (E-1) The silicone surfactant is not particularly limited. Examples of the silicone surfactant include "BYK-307", "BYK-333", "BYK-347", "BYK-348", "BYK-349", "BYK-345", "BYK-378", and "BYK-3455" (all manufactured by BYK-Chemie).

[0066] The acetylene surfactant is not particularly limited. Examples include "Olfine (registered trademark) E1004", "Olfine (registered trademark) E1008", "Olfine (registered trademark) E1010" (all manufactured by Nissin Chemical Industry Co., Ltd.), "Surfynol (registered trademark) 440", "Surfynol (registered trademark) 465", "Surfynol (registered trademark) 485" (all manufactured by Air Products and Chemicals Co., Ltd.), "Acetylenol (registered trademark) E40", "Acetylenol (registered trademark) E100" (all manufactured by Kawaken Fine Chemicals Co., Ltd.), etc.

[0067] The content of the nonionic surfactant (E-1) in the ink composition is preferably 0.1% by mass to 3% by mass.

[0068] Nonionic surfactants (E-2) other than surfactants (E-1) An example of the nonionic surfactant (E-2) other than the surfactant (E-1) is a nonionic surfactant (E-2) other than the surfactant (E-1) that has multiple polyoxyalkylene groups in the molecule and has an HLB value of 10 or more and less than 15.5.

[0069] The HLB value is an index that indicates the degree of hydrophilicity and lipophilicity of a surfactant, calculated by the Griffin method. The smaller the HLB value, the higher the lipophilicity, and the higher the HLB value, the higher the hydrophilicity.

[0070] The nonionic surfactant (E-2) has multiple polyoxyalkylene groups (two or more polyoxyalkylene chains) in the molecule. From the viewpoint of improving the printability and bleeding resistance of a solid image by the aqueous inkjet ink composition, the nonionic surfactant (E-2) preferably has at least a polyoxyethylene group. In this embodiment, for example, a polyoxyalkylene group in which a polyoxyethylene group and a polyoxypropylene group are directly linked (condensed) is counted as one. The molecular skeleton of the nonionic surfactant (E-2) is not limited in any way as long as it has the above-mentioned HLB value and multiple polyoxyalkylene groups (two or more polyoxyalkylene chains) in the molecule. For example, the nonionic surfactant (E-2) is a polyoxyalkylene group-containing fatty acid glyceryl, a polyoxyalkylene group-containing aliphatic amine, a polyoxyalkylene group-containing sorbitan fatty acid ester, etc.

[0071] The content of the nonionic surfactant (E-2) in the ink composition is preferably 0.005% by mass to 2% by mass.

[0072] 2,4,7,9-Tetramethyl-4,7-decanediol (E-3) [ka]

[0073] The content of 2,4,7,9-tetramethyl-4,7-decanediol (E-3) in the ink composition is preferably 0.005% by mass to 3.5% by mass.

[0074] The total amount of the nonionic surfactant (E-2) and 2,4,7,9-tetramethyl-4,7-decanediol (E-3) in the ink composition may be 3.8% by mass or less, and is preferably 3.5% by mass or less. The total amount of the nonionic surfactant (E-2) and 2,4,7,9-tetramethyl-4,7-decanediol (E-3) in the ink composition is preferably 0.05% by mass or more, and more preferably 0.5% by mass or more. If the total amount of the nonionic surfactant (E-2) and 2,4,7,9-tetramethyl-4,7-decanediol (E-3) in the ink composition exceeds 3.8% by mass, the ink composition has problems such as reduced storage stability, continuous discharge stability, and blocking property.

[0075] The content of the surfactant in the ink composition is 0.03 to 10% by mass, and preferably 0.05 to 6% by weight.

[0076] The surfactants include one or more nonionic surfactants (E-1) selected from the group consisting of acetylene-based surfactants and silicone-based surfactants, one or more nonionic surfactants (E-2) selected from the group consisting of polyoxyalkylene group-containing fatty acid glyceryls, polyoxyalkylene group-containing aliphatic amines, and polyoxyalkylene group-containing sorbitan fatty acid esters, which have multiple polyoxyalkylene groups in their molecules other than the surfactant (E-1) and have an HLB value of 10 or more and less than 15.5, and 2,4,7,9-tetramethyl-4,7-decanediol (E-3). By containing a specific amount of nonionic surfactant (E-2), the ink composition of this embodiment has good leveling properties even when printed on a low-absorbency substrate or a non-absorbency substrate, and when a solid image is printed, the solid image is also well filled.

[0077] (water) Water is blended to impart fluidity to the ink composition. Water evaporates when heated. The water is preferably pure water or ultrapure water, such as ion-exchanged water, ultrafiltered water, reverse osmosis water, or distilled water, from which ionic impurities have been removed as much as possible. In addition, water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferably used, since it can suppress the growth of mold and bacteria when the pigment dispersion and the ink composition using the same are stored for a long period of time.

[0078] The water content is not particularly limited. For example, the water content in the ink composition is preferably 10% by mass or more, and more preferably 30% by mass or more. The water content in the ink composition is preferably 70% by mass or less, and more preferably 50% by mass or less. When the water content is within the above range, the ink composition can exhibit appropriate fluidity.

[0079] (optional ingredient) The ink composition of the present embodiment may contain various additives, such as a pigment dispersant, a surfactant other than the above-mentioned surfactants, a pH adjuster, a crosslinking agent, oil droplet fine particles, an ultraviolet absorber, a discoloration inhibitor, a fluorescent brightening agent, a polysaccharide, a viscosity adjuster, a resistivity adjuster, a film-forming agent, an antioxidant, an anti-fungal agent, an anti-rust agent, and a charge adjuster, as appropriate.

[0080] <Method of manufacturing ink composition> The method for producing the ink composition according to an embodiment of the present invention is not particularly limited. For example, the ink composition may be prepared by adding and mixing the above-mentioned components in order or simultaneously. For example, (1) A method of mixing an aqueous resin varnish prepared by dissolving an alkali-soluble resin in water in the presence of the basic compound, a pigment, and, if necessary, a pigment dispersant, etc., and then preparing a pigment dispersion (ink base) using various dispersing machines, such as a ball mill, attritor, roll mill, sand mill, agitator mill, etc., and further adding the remaining materials to prepare an aqueous inkjet ink composition; (2) A method in which, after dispersing the pigment by the above method, an alkali-soluble resin is precipitated on the pigment surface by an acid precipitation method or an ion exchange means as described in WO 2005 / 116147 to obtain a resin-coated pigment, the resin-coated pigment thus obtained is then neutralized with a basic compound, and the pigment is redispersed in water using various dispersing machines (such as a high-speed stirring device), and the remaining materials are further added to prepare an aqueous inkjet ink composition; (3) A method for producing an aqueous pigment-type inkjet ink composition, comprising forming a coating layer on a pigment surface with an alkali-soluble resin in which a portion of the acid groups are neutralized with a basic compound, as described in JP2017-149906A, crosslinking the coating layer with a bifunctional or higher crosslinking agent to obtain a coated pigment, and then adding the remaining materials; etc.

[0081] <Printed matter and inkjet printing method> The printed matter of one embodiment of the present invention can be produced by ejecting droplets of the ink composition from an inkjet head of a known inkjet printing device (inkjet printer) and landing them on the surface of a substrate to form an image. A non-water-absorbent film substrate or the like may be attached to the printed layer formed using the ink composition via a laminating adhesive layer.

[0082] As described above, the ink composition has good leveling properties even when printed on a low-absorbency substrate or a non-absorbency substrate, and when a solid image is printed, it also has good solid filling.

[0083] The low-absorbency substrate or non-absorbency substrate can be defined based on the measurement results of the wettability of the recording medium surface to water shown below. That is, a 0.5 μL water droplet is dropped on the recording surface of the recording medium, and the absorption performance of the recording medium is characterized by measuring the contact angle decrease rate (comparison of the contact angle at 0.5 milliseconds after landing with the contact angle at 5 seconds). More specifically, in terms of the nature of the recording medium, a non-absorbency recording medium is a recording medium having a contact angle decrease rate of less than 1.0%, and a low-absorbency recording medium is a recording medium having a contact angle decrease rate of 1.0% or more and less than 5.0%. Absorbency is defined as a recording medium having a contact angle decrease rate of 5.0% or more. The contact angle can be measured, for example, using a portable contact angle meter "PCA-1" (manufactured by Kyowa Interface Science Co., Ltd.).

[0084] The low absorbent or non-absorbent substrate is not particularly limited. For example, the low absorbent or non-absorbent substrate includes known plastic films. The plastic film includes biodegradable films such as polyester (PET) film, polyethylene (PE) film, polypropylene (PP) film, nylon (NY) film, polystyrene (PS) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl chloride (PVC) film, polyvinyl alcohol (PVA) film, polyacrylic acid (PAA) film, polycarbonate film, polyacrylonitrile film, and polylactic acid film.

[0085] These films may be coated with polyvinylidene chloride on one or both sides thereof or may be vapor-deposited with a metal oxide in order to impart gas barrier properties, moisture resistance, aroma retention, etc. The films may also be subjected to an anti-fogging treatment. The films may also be subjected to a corona discharge or ozone treatment.

[0086] Furthermore, the film may be an unstretched film or a stretched film.

[0087] The substrate may also be a multi-layer substrate in which a layer such as a PVA coat is provided on the surface of an absorbent substrate such as paper, making the area to be recorded non-absorbent.

[0088] The ink composition of the present embodiment may be applied to an absorbent substrate. The absorbent substrate is not particularly limited. For example, the absorbent substrate may be plain paper ranging from thin paper to thick paper, high-quality paper, art paper, coated printing paper, or the like.

[0089] The inkjet head may be either an on-demand type or a continuous type. On-demand type inkjet heads include electro-mechanical conversion type heads, such as single cavity type, double cavity type, bender type, piston type, shear mode type, and shared wall type, and electro-thermal conversion type heads, such as thermal inkjet type and bubble jet type heads ("Bubble Jet" is a registered trademark of Canon Inc.).

[0090] The inkjet head may be either a scanning type or a line type inkjet head.

[0091] The transport speed of the substrate is not particularly limited. For example, the transport speed is 1 to 120 m / min. The substrate may be a substrate (for example, a film) stored in a roll. EXAMPLES

[0092] The present invention will be described in more detail below with reference to the following examples. The present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass".

[0093] The raw materials and preparation methods used are shown below. <Preparation of water-based resin varnish> 25 parts by mass of acrylic acid / stearyl acrylate / styrene copolymer (alkali-soluble resin, acid value 180 mgKOH / g, glass transition temperature 50°C, mass average molecular weight 30,000) was dissolved in a mixed solution of 4.9 parts by mass of potassium hydroxide and 70.1 parts by mass of water to obtain an aqueous resin varnish with a solid content of 25% by mass. <Water-based pigment ink> -Water-based white pigment ink 28 parts by mass of water was added to 32 parts by mass of the above-mentioned aqueous resin varnish and mixed to prepare a resin varnish for dispersing pigment. 40.0 parts by mass of titanium oxide pigment (CR-90, manufactured by Ishihara Sangyo Kaisha, Ltd.) was added to this varnish, stirred and mixed, and then milled in a wet circulation mill to obtain a pigment dispersion (solid concentration 40% by mass). -Water-based yellow pigment ink 32 parts by mass of the above-mentioned aqueous resin varnish was mixed with 48 parts by mass of water to prepare a resin varnish for dispersing pigments. 20 parts by mass of a yellow pigment (Novaperm Yellow 4G01, Clariant) was further added to this varnish, stirred and mixed, and then milled in a wet circulation mill to prepare an aqueous yellow ink base (solid concentration 20% by mass). Water-based magenta pigment ink 48 parts by mass of water was added to 32 parts by mass of the above-mentioned aqueous resin varnish and mixed to prepare a resin varnish for dispersing pigment. 20 parts by mass of magenta pigment (Inkjet Magenta E5B02, Clariant) was further added to this varnish, stirred and mixed, and then milled in a wet circulation mill to prepare an aqueous magenta pigment ink base (solid concentration 20% by mass). -Water-based cyan pigment ink 32 parts by mass of the aqueous resin varnish was mixed with 48 parts by mass of water to prepare a resin varnish for dispersing pigments. 20 parts by mass of a cyan pigment (Heliogen Blue L7101F, manufactured by BASF) was further added to this varnish, stirred and mixed, and then milled in a wet circulation mill to prepare an aqueous cyan pigment base (solid content concentration 20% by mass). -Water-based black pigment ink 48 parts by mass of water was added to 32 parts by mass of the above aqueous resin varnish and mixed to prepare a resin varnish for dispersing pigments. 20 parts by mass of carbon black (Printex 90, manufactured by Degussa) was further added to this varnish, stirred and mixed, and then milled in a wet circulation mill to prepare an aqueous cyan pigment base (solid content concentration 20% by mass). · Aqueous pigment dispersion of cyan pigment coated with alkali-soluble resin The aqueous cyan pigment-based ink was diluted with water to a pigment concentration of 5%, and then 5% of a cation exchange resin (DOWEX MONOSPHERE (H) 650C, manufactured by Dow Chemical Co.) was added to the diluted solution and stirred to carry out ion exchange until the pH became less than 4, to obtain a resin-coated pigment. The ion exchange resin was then filtered through a mesh and then suction filtered to obtain a water-containing cake (solid content 25%) containing the resin-coated pigment. Potassium hydroxide was added to the water-containing cake containing the resin-coated pigment to neutralize 65% of the alkali-soluble resin acid value in the resin-coated pigment, and water was added to the water-containing cake containing the resin-coated pigment so that the pigment concentration became 12% by mass, and the mixture was stirred with a high-pressure emulsifying and dispersing device: Gaulin Homogenizer (manufactured by APV Gaulin Ink.) to obtain an aqueous pigment dispersion of a cyan pigment coated with an alkali-soluble resin. <Resin fine particles> AQUACER531 (polyethylene resin, manufactured by BYK) Yodosol AD173 (acrylic resin, manufactured by Henkel) NeoCryl A-1092 (styrene-acrylic resin, manufactured by Covestro) Vinyblan 1245L (vinyl acetate-acrylic resin, manufactured by Nissin Chemical Industry Co., Ltd.) Vinyblan 278 (vinyl chloride-acrylic resin, manufactured by Nissin Chemical Industry Co., Ltd.) Vinyblan GV6181 (vinyl acetate resin, manufactured by Nissin Chemical Industry Co., Ltd.) Superflex 740 (polyester polyurethane resin, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) NeoRez R-966 (polyether polyurethane resin, manufactured by Covestro) Superflex 420NS (polycarbonate-based polyurethane resin, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Sepolsion ES (polyester resin, manufactured by Sumitomo Seika Chemicals Co., Ltd.) <Surfactant> The surfactants used were as shown in Table 1 below.

[0094] [Table 1]

[0095] <Production of aqueous inkjet ink composition> The materials were mixed by stirring so as to obtain the mass ratios shown in Tables 2 to 5 below, thereby obtaining aqueous inkjet ink compositions of Examples 1 to 28 and Comparative Examples 1 to 6.

[0096] [Table 2]

[0097] [Table 3]

[0098] [Table 4]

[0099] [Table 5]

[0100] The obtained ink composition was evaluated for storage stability, ejection stability, continuous ejection stability, abrasion resistance, blocking resistance, and image quality by the following evaluation methods. The results are shown in Tables 2 to 5.

[0101] <Evaluation of ejection of aqueous inkjet ink composition> (Storage stability) The aqueous inkjet ink compositions of Examples 1 to 28 and Comparative Examples 1 to 6 were each placed in a glass bottle, and the viscosity at 25°C was measured using a viscometer (RE100L model, manufactured by Toki Sangyo Co., Ltd.). The bottles were then sealed and stored at 60°C for one month, and the viscosity after storage (25°C) was measured using the viscometer. The stability over time was evaluated as the rate of viscosity change (viscosity after one month at 60°C - viscosity before storage / viscosity before storage). Evaluation criteria ◯: The viscosity change rate was less than 5%. △: Viscosity change rate was 5% or more and less than 10%. ×: The viscosity change rate was 10% or more and less than 30%. (Discharge stability) The aqueous inkjet ink compositions of Examples 1 to 28 and Comparative Examples 1 to 6 were filled into the cartridges of an Epson printer PX105, and printing was performed on photo paper GL-101A450 (Canon Inc.) or shielding paper (W ink only) to evaluate the ejection stability. Evaluation criteria ◯: There was no disturbance in the printing and the ink was discharged stably. △: There was some disturbance in the printing, but the ink could be discharged. ×: Printing was disturbed and stable ejection was not possible. (Continuous discharge stability) The aqueous inkjet ink compositions of Examples 1 to 28 and Comparative Examples 1 to 6 were filled into the cartridges of an Epson printer PX105, and 50 solid images measuring 15 cm x 20 cm were printed continuously on photo paper GL-101A450 (Canon Inc.) or shielding paper (W ink only) to evaluate continuous ejection properties. Evaluation criteria ◯: The image quality was good and the ink was discharged stably. ×: Deterioration in image quality such as streaks was observed, and stable ejection was not possible. (Abrasion resistance) The print was dried in an oven at 80° C. for 3 minutes, and then the print surface was rubbed with a cotton swab to evaluate the abrasion resistance. Evaluation criteria ◯: The coating surface was not scratched at all even after rubbing with a cotton swab 10 times. △: After rubbing the coating surface with a cotton swab 10 times, the color transferred to the cotton swab and the rubbed area was slightly faded. ×: After the coating surface was rubbed with a cotton swab 10 times, the rubbed area completely peeled off. (Blocking property) The aqueous inkjet ink compositions of Examples 1 to 28 and Comparative Examples 1 to 6 were filled into the cartridges of an Epson printer PX105, and a 15 cm x 20 cm solid image was printed on an OK Topcoat+ (Oji Paper Co., Ltd.) low-absorbency substrate. After printing, the printed surface was overlaid with an unprinted OK Topcoat+ (Oji Paper Co., Ltd.), and the resulting image was subjected to a pressure of 9.8 x 104 Pa (1 kgf / cm 2 After leaving it for 24 hours, it was peeled off and blocking resistance was evaluated. ○: There was absolutely no peeling of the printed coating. ×: The printed film peeled off, and strong resistance to peeling was felt. (image quality) The aqueous inkjet ink compositions of Examples 1 to 28 and Comparative Examples 1 to 6 were loaded into the cartridges of an Epson printer PX105, and a 15 cm x 20 cm solid image was printed on photo paper GL-101A450 (Canon Inc.) or shielding paper (W ink only) as an absorbent substrate, and OK Topcoat+ (Oji Paper Co., Ltd.) as a low-absorbent substrate, and the degree of filling of the solid areas of the prints was visually evaluated. Evaluation criteria ◯: The solid areas were completely filled in, with almost no streaking. ×: Streaks were noticeable throughout the entire area.

[0102] As shown in Tables 2 to 5, the ink compositions of Examples 1 to 28 of the present invention had excellent storage stability and ejection stability. Furthermore, the ink compositions of Examples 1 to 28 of the present invention had good leveling properties even when printed on a low-absorbency substrate or a non-absorbency substrate, and when a solid image was printed, the solid filling was good, and the abrasion resistance and blocking properties were also good.

Claims

1. The composition comprises a colorant (A), an anionic group-containing resin (B), a water-soluble organic solvent (C), resin fine particles (D), a surfactant (E), and water (F), The surfactant (E) includes one or more nonionic surfactants (E-1) selected from the group consisting of acetylene-based surfactants and silicone-based surfactants, a nonionic surfactant (E-2) other than the nonionic surfactant (E-1), and 2,4,7,9-tetramethyl-4,7-decanediol (E-3), The nonionic surfactant (E-2) is one or more nonionic surfactants selected from the group consisting of polyoxyalkylene group-containing fatty acid glyceryls, polyoxyalkylene group-containing aliphatic amines, and polyoxyalkylene group-containing sorbitan fatty acid esters, each of which has a plurality of polyoxyalkylene groups in its molecule and has an HLB value of 10 or more and less than 15.5; The total amount of the nonionic surfactant (E-2) and 2,4,7,9-tetramethyl-4,7-decanediol (E-3) in the ink composition is 3.8% by mass or less.

2. 2. The ink composition for ink-jet printing according to claim 1, wherein the water-soluble organic solvent (C) contains an organic solvent having a boiling point of 120 to 200.degree.

3. The ink composition for ink-jet printing according to claim 1 , wherein the resin fine particles (D) contain at least one of a wax and an emulsion.

Images