Image forming method and image forming apparatus

Abstract

To provide an image forming method capable of achieving excellent drying properties even when using an aqueous curable ink.SOLUTION: The image forming method includes: an application step of applying a curable composition containing water and a polymerizable compound onto a recording medium; an active energy ray irradiation step of irradiating, with an active energy ray, the recording medium onto which the curable composition has been applied; and a drying step of bringing the recording medium after the irradiation into contact with a heatable rotor to heat the recording medium. The polymerizable compound contains a tri- or higher functional polymerizable compound. The content of the water is higher than the content of the polymerizable compound.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a curable composition, a curable ink, a storage container, an image forming method, an image forming apparatus, a two-dimensional or three-dimensional image forming apparatus, a two-dimensional or three-dimensional image forming method, and a printed matter. [Background technology]

[0002] As inkjet recording inks, water-based pigment inks and water-based dye inks are generally used from the viewpoints of environmental friendliness and safety, but water-based inks in general require a large amount of energy to dry the water and solvent. On the other hand, solvent-based inks using highly volatile solvents, ultraviolet (UV) inks using ultraviolet rays or electron beams, or electron beam (EB) inks are used in fields where high productivity is required. However, due to safety concerns about solvent-based inks, UV inks, and EB inks, the demand for water-based inks is increasing in the market.

[0003] In recent years, aqueous pigment inks have been proposed that contain water as a base agent and a radical-reactive polymerizable material having a (meth)acrylate structure as part of its structure, and that can form an ink film having abrasion resistance through a radical reaction (see, for example, Patent Document 1). Thus, there is a demand for inks that have the environmental friendliness and safety of water-based inks, while also having the excellent drying properties of solvent-based inks, UV inks, or EB inks. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an image forming method that can achieve excellent drying properties even when a water-based curable ink is used. [Means for solving the problem]

[0005] The image forming method of the present invention as a means for solving the above-mentioned problems includes an application step of applying a curable composition containing water and a polymerizable compound onto a recording medium, an active energy ray irradiation step of irradiating the recording medium to which the curable composition has been applied with active energy ray irradiation, and a drying step of contacting the irradiated recording medium with a heatable rotating body and heating it, wherein the polymerizable compound includes a tri- or higher functional polymerizable compound, and the content of the water is greater than the content of the polymerizable compound. Effect of the Invention

[0006] According to the present invention, it is possible to provide an image forming method capable of realizing excellent drying properties even when a water-based curable ink is used. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an example of a two-dimensional or three-dimensional image forming apparatus according to the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing another example of a two-dimensional or three-dimensional image forming apparatus according to the present invention. [Diagram 3] FIG. 3 is a schematic diagram showing another example of a two-dimensional or three-dimensional image forming apparatus according to the present invention. [Figure 4] FIG. 4 is a schematic diagram showing an example of an image forming apparatus used in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (Image forming method and image forming apparatus) The image forming method of the present invention includes a step of applying a curable composition containing water and a polymerizable compound onto a recording medium, a step of irradiating the recording medium to which the curable composition has been applied with an active energy ray, and a step of drying the irradiated recording medium by contacting it with a heatable rotating body, wherein the polymerizable compound includes a trifunctional or higher functional polymerizable compound, the content of the water is greater than the content of the polymerizable compound, and the method further includes other steps as necessary.

[0009] The image forming apparatus of the present invention comprises an applying means for applying a curable composition containing water and a polymerizable compound onto a recording medium, an active energy ray irradiating means for irradiating the recording medium to which the curable composition has been applied with active energy ray irradiation, and a drying means for contacting the irradiated recording medium with a heatable rotating body to dry it, wherein the polymerizable compound comprises a trifunctional or higher functional polymerizable compound, the content of the water is greater than the content of the polymerizable compound, and the apparatus further comprises other means as necessary.

[0010] The image forming method of the present invention can be suitably carried out by the image forming apparatus of the present invention, and the application step can be carried out by an application means, the active energy ray irradiation step can be carried out by an active energy ray irradiation means, the drying step can be carried out by a drying means, and the other steps can be carried out by other means.

[0011] Conventional technology uses water-based curing ink, which requires a large amount of energy to dry the water. In particular, in high-speed industrial machines, a processing liquid is applied, the processing liquid is dried, an image is formed with water-based curing ink, and then a drying process is performed using hot air or a halogen lamp, and finally UV irradiation is performed. This requires a large number of steps, which results in a large amount of energy being consumed for drying and a large drying space being required.

[0012] The present inventors have conducted extensive research in light of the above problems and have found that by forming an image using a curable composition containing a trifunctional or higher polymerizable compound, irradiating the image with active energy rays, and then drying the image by contacting a heatable rotating body (heat roller) with the image surface, the number of steps and the drying energy can be significantly reduced compared to the conventional method, without transferring the image to the heat roller.

[0013] Therefore, the present invention includes an application step of applying a curable composition containing water and a polymerizable compound onto a recording medium, an active energy ray irradiation step of irradiating the recording medium to which the curable composition has been applied with active energy ray irradiation, and a drying step of contacting the irradiated recording medium with a heatable rotating body and drying it, wherein the polymerizable compound includes a tri- or higher functional polymerizable compound and the content of the water is greater than the content of the polymerizable compound, so that excellent drying properties can be achieved even when a water-based curable ink is used.

[0014] The curable composition of the present invention used in the image forming method and image forming apparatus of the present invention will now be described.

[0015] (Curable composition) The curable composition of the present invention contains water and a polymerizable compound, and preferably contains a polymerization initiator and a coloring material, and further contains other components as necessary.

[0016] <Polymerizable compound> The polymerizable compound includes a trifunctional or higher polymerizable compound, and may contain other polymerizable compounds as necessary. In the present invention, by using a trifunctional or higher polymerizable compound, there is an advantage that even if an object or the like comes into contact with the image surface, the curable composition (curable ink) is not transferred to the object.

[0017] - Polymerizable compounds with three or more functional groups - The tri- or higher functional polymerizable compound is preferably a polyfunctional polymerizable compound having from three to six functionalities. Examples of the trifunctional or higher polymerizable compound include dipentaerythritol hexa(meth)acrylate, propylene oxide modified tetramethylolmethane tetra(meth)acrylate, dipentaerythritol hydroxypenta(meth)acrylate, caprolactone modified dipentaerythritol hydroxypenta(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane triacrylate, and ethylene Oxide modified trimethylolpropane tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, caprolactone modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, propylene oxide modified glyceryl tri(meth)acrylate, polyester tri(meth)acrylate, polyester tetra(meth)acrylate, poly Polyester penta(meth)acrylate, polyurethane tri(meth)acrylate, polyurethane tetra(meth)acrylate, polyurethane penta(meth)acrylate, EO modified pentaerythritol tri(meth)acrylate, PO modified pentaerythritol tri(meth)acrylate, EO modified pentaerythritol tetra(meth)acrylate, PO modified pentaerythritol tetra(meth)acrylate, EO modified dipentaerythritol tetra(meth)acrylate, PO modified dipentaerythritol Examples of the ethoxylated pentaerythritol tetra(meth)acrylate include ethoxylated pentaerythritol tetra(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO-modified tetramethylolmethane tetra(meth)acrylate, PO-modified tetramethylolmethane tetra(meth)acrylate, ethoxylated glycerin tri(meth)acrylate (20 mol addition), ethoxylated pentaerythritol tetra(meth)acrylate (35 mol addition), polyglycerin acrylate (6 functional), etc. These may be used alone or in combination of two or more.Among these, in terms of solubility in water, the above acrylates having an amide group, a hydroxyl group, an EO chain, or a PO chain in the molecule are preferred.

[0018] The tri- or higher functional polymerizable compound is preferably water-soluble. Here, being water-soluble means that the solubility of a polymerizable compound having three or more functional groups in water at 25° C. is 10 g / 100 g of water or more. The use of a water-soluble tri- or higher functional polymerizable compound has the advantage that the viscosity of the curable composition (curable ink) can be kept low even when a polyfunctional polymerizable compound is used. Examples of water-soluble trifunctional or higher polymerizable compounds include ethoxylated glycerin triacrylate (trifunctional, 20 mol addition), ethoxylated pentaerythritol tetraacrylate (tetrafunctional, 35 mol addition), polyglycerin acrylate (hexafunctional), and ethoxylated glycerin triacrylate (trifunctional, 3 mol addition).

[0019] The content of the tri- or higher functional polymerizable compound is preferably from 1% by mass to 20% by mass, more preferably from 5% by mass to 15% by mass, based on the total amount of the curable composition. When the content of the tri- or higher functional polymerizable compound is 5% by mass or more and 15% by mass or less, there is an advantage that an increase in viscosity can be suppressed.

[0020] In the curable composition of the present invention, in addition to the above-mentioned tri- or higher functional polymerizable compound, other polymerizable compounds can be used in combination. Examples of the other polymerizable compounds that can be used in combination include (meth)acrylates, (meth)acrylamides, and vinyl ethers. More specifically, examples of the polymerizable compounds that can be used in combination include ethylene glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, γ-butyrolactone (meth)acrylate, isobornyl (meth)acrylate, formalized trimethylolpropane mono(meth)acrylate, polytetramethylene glycol di(meth)acrylate, trimethylolpropane (meth)acrylic acid benzoate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and polyethylene glycol diacrylate [CH2=CH-CO-(OC2H4) n -OCOCH=CH2(n≒4)】, polyethylene glycol diacrylate [CH2=CH-CO-(OC2H4)n-OCOCH=CH2(n≒9)], polyethylene glycol diacrylate [CH2=CH-CO-(OC2H4)n-OCOCH=CH2(n≒14)], polyethylene glycol diacrylate [CH2=CH-CO-(OC2H4)n-OCOCH=CH2(n≒23)], dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol dimethacrylate [CH2=C(CH3)-CO-(OC3H6) n-OCOC(CH3)=CH2(n≒7)】, 1,3-butanediol di(meth)acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate, propylene oxide modified bisphenol A di(meth)acrylate, polyethylene glycol di(meth)acrylate, (meth)acryloylmorpholine, neopentyl glycol diacrylate, ethoxylated neopentyl glycol di(meth)acrylate, propylene oxide modified neopentyl glycol di(meth)acrylate Examples of the polymerizable compound include glycol di(meth)acrylate, polyester di(meth)acrylate, polyurethane di(meth)acrylate, 2-hydroxypropyl(meth)acrylamide, N-vinylcaprolactam, N-vinylpyrrolidone, N-vinylformamide, cyclohexane dimethanol monovinyl ether, cyclohexane dimethanol divinyl ether, hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, diethylene glycol divinyl ether, dicyclopentadiene vinyl ether, tricyclodecane vinyl ether, benzyl vinyl ether, and ethyloxetane methyl vinyl ether. These may be used alone or in combination of two or more. Among these, water-soluble polymerizable compounds are preferred.

[0021] <Polymerization initiator> The curable composition of the present invention may contain a polymerization initiator. The polymerization initiator may be any one that can generate active species such as radicals and cations by the energy of active energy rays and initiate the polymerization of a polymerizable compound (monomer or oligomer). As such a polymerization initiator, radical polymerization initiators, cationic polymerization initiators, base generators, etc. can be used alone or in combination of two or more. Among these, it is preferable to use a radical polymerization initiator. Examples of the radical polymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds. The content of the polymerization initiator is preferably from 0.5% by mass to 20% by mass, and more preferably from 1% by mass to 10% by mass, based on the total amount of the curable composition.

[0022] In addition to the polymerization initiator, a polymerization accelerator (sensitizer) can also be used in combination. The polymerization accelerator is not particularly limited, but for example, amine compounds such as trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, 2-ethylhexyl p-dimethylaminobenzoate, N,N-dimethylbenzylamine, and 4,4'-bis(diethylamino)benzophenone are preferred, and the content thereof may be appropriately set according to the polymerization initiator used and its amount. Particularly preferred are water-soluble polymerization initiators, and photopolymerization initiators having a hydroxyl group in the molecule are preferred. The photopolymerization initiator skeleton is preferably an alkylphenone-based or monoacylphosphine oxide-based polymerization initiator.

[0023] <Water> The water is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, and ultrapure water, etc. These may be used alone or in combination of two or more kinds. The water content is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of drying property, the water content is preferably from 10% by mass to 80% by mass, and more preferably from 20% by mass to 65% by mass, based on the total amount of the curable composition. The content of the water must be greater than the content of the polymerizable compound, and is preferably greater than the content of the polymerizable compound (the total content when two or more kinds are contained) by 20 mass % or more. If the content of the water is less than the content of the polymerizable compound, there is a drawback in that the curability is deteriorated.

[0024] <Coloring material> The coloring material is not particularly limited, and pigments and dyes can be used. As the pigment, inorganic pigments or organic pigments can be used. These can be used alone or in combination of two or more. Mixed crystals can also be used. Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver pigments, and metallic pigments. Examples of inorganic pigments that can be used include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, as well as carbon black produced by known methods such as the contact method, furnace method, and thermal method. Examples of organic pigments that can be used include azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dye chelates (e.g., basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc. Among these pigments, those with good affinity to the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used. Specific examples of pigments for black colors include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black; metals such as copper, iron (CI Pigment Black 11), and titanium oxide; and organic pigments such as aniline black (CI Pigment Black 1). In addition, for color, CI Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, CI Pigment Orange Range 5, 13, 16, 17, 36, 43, 51, CI Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48:2 (Permanent Red 2B (Ca)), 48:3, 48:4, 49:1, 52:2, 53:1, 57:1 (Brilliant Carmine 6B), 60:1, 63:1, 63:2, 64:1, 81, 83, 88, 101 ( Red iron oxide), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, CI Pigment Examples of pigments include CI Pigment Green 1, 4, 7, 8, 10, 17, 18, and 36.

[0025] The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. One type of dye may be used alone, or two or more types may be used in combination. Examples of the dyes include CI Acid Yellow 17, 23, 42, 44, 79, 142, CI Acid Red 52, 80, 82, 249, 254, 289, CI Acid Blue 9, 45, 249, CI Acid Black 1, 2, 24, 94, CI Food Black 1, 2, CI Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, and CI Direct Red. 1, 4, 9, 80, 81, 225, 227, CI Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, CI Directed Black 19, 38, 51, 71, 154, 168, 171, 195, CI Reactive Red 14, 32, 55, 79, 249, CI Reactive Black 3, 4, 35, etc.

[0026] The content of the coloring material in the ink is preferably from 0.1% to 15% by mass, and more preferably from 1% to 10% by mass, from the viewpoints of improving image density, good fixing property, and ejection stability.

[0027] Methods for dispersing a pigment in an ink include a method of introducing a hydrophilic functional group into the pigment to make it a self-dispersing pigment, a method of dispersing the pigment by coating the surface of the pigment with a resin, and a method of dispersing the pigment using a dispersant. As a method for making a pigment into a self-dispersing pigment by introducing a hydrophilic functional group, for example, a self-dispersing pigment that can be dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to a pigment (e.g., carbon) can be used. As a method for coating the surface of a pigment with a resin and dispersing it, a method for encapsulating the pigment in a microcapsule and dispersing it in water can be used. This can be called a resin-coated pigment. In this case, it is not necessary for all the pigments blended in the ink to be coated with a resin, and uncoated or partially coated pigments may be dispersed in the ink as long as the effects of the present invention are not impaired. Examples of the method for dispersing using a dispersant include a method for dispersing using a known low molecular weight dispersant or a polymeric dispersant, typified by a surfactant. As the dispersant, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. can be used depending on the pigment. RT-100 (nonionic surfactant) manufactured by Takemoto Oil Co., Ltd. and sodium naphthalenesulfonate formalin condensate can also be suitably used as the dispersant. The dispersants may be used alone or in combination of two or more.

[0028] -Pigment dispersion- It is possible to obtain ink by mixing a pigment with materials such as water or an organic solvent, or it is also possible to manufacture ink by mixing a pigment with other materials such as water or a dispersant to prepare a pigment dispersion, and then mixing the resulting mixture with materials such as water or an organic solvent. The pigment dispersion is obtained by dispersing water, a pigment, a pigment dispersant, and other components as required, and adjusting the particle size. Dispersion is preferably performed using a dispersing machine. The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency in terms of the maximum number is preferably 20 nm or more and 500 nm or less, and more preferably 20 nm or more and 150 nm or less, in order to improve the dispersion stability of the pigment and the image quality such as ejection stability and image density. The particle size of the pigment can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.). The content of the pigment in the pigment dispersion is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoints of obtaining good ejection stability and increasing image density, the content is preferably from 0.1% by mass to 50% by mass, and more preferably from 0.1% by mass to 30% by mass. It is preferable that the pigment dispersion is degassed, if necessary, by filtering coarse particles using a filter, a centrifugal separator, or the like.

[0029] <Other ingredients> Examples of the other components include resins, organic solvents, surfactants, antifoaming agents, antiseptic and antifungal agents, rust inhibitors, and pH adjusters.

[0030] -resin- The type of resin contained in the curable composition is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, and acrylic-silicone resin. Resin particles made of these resins may be used. Resin particles are dispersed in water as a dispersion medium, and mixed with materials such as coloring materials and organic solvents to obtain a curable composition. The resin particles may be appropriately synthesized or commercially available. These may be used alone or in combination of two or more types of resin particles.

[0031] The volume average particle size of the resin particles is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of obtaining good fixing property and high image hardness, however, it is preferably from 10 nm to 1,000 nm, more preferably from 10 nm to 200 nm, and particularly preferably from 10 nm to 100 nm. The volume average particle size can be measured, for example, using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac-Bell Co., Ltd.).

[0032] The particle size of the solid content in the curable composition is not particularly limited and can be appropriately selected according to the purpose, but in terms of improving image quality such as ejection stability and image density, the maximum frequency in terms of maximum number is preferably 20 nm or more and 1000 nm or less, more preferably 20 nm or more and 150 nm or less. The solid content includes resin particles, pigment particles, etc. The particle size can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

[0033] -Organic solvents- The organic solvent used in the present invention is not particularly limited, and any water-soluble organic solvent can be used. Examples of the water-soluble organic solvent include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds. Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol (propanediol), 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5 -Pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol and other polyhydric alcohols; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene Examples of the alkyl ethers include polyhydric alcohols such as glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; polyhydric alcohols such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone; amides such as formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide; amines such as 3-methoxy-3-methyl-1-butanol, monoethanolamine, diethanolamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate, and ethylene carbonate. It is preferable to use an organic solvent having a boiling point of 250° C. or less, since this not only functions as a wetting agent but also provides good drying properties.

[0034] Polyol compounds having 8 or more carbon atoms and glycol ether compounds are also suitably used. Specific examples of polyol compounds having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. Specific examples of the glycol ether compound include polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; and polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

[0035] Polyol compounds having 8 or more carbon atoms and glycol ether compounds can improve the permeability of ink when paper is used as the recording medium.

[0036] The content of the organic solvent is preferably 10% by mass or more and 60% by mass or less, more preferably 20% by mass or more and 60% by mass or less, based on the total amount of the curable composition. When the content is 10% by mass or more, the wettability to a recording medium is improved, and when the content is 60% by mass or less, the sharpness and drying property of a printed image are improved.

[0037] -Surfactants- As the surfactant, any of silicone-based surfactants, fluorine-based surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used. Silicone surfactants are not particularly limited and can be appropriately selected according to purpose.Among them, those that do not decompose even at high pH are preferred, such as side chain modified polydimethylsiloxane, both end modified polydimethylsiloxane, one end modified polydimethylsiloxane, side chain both end modified polydimethylsiloxane, etc., and those having polyoxyethylene group or polyoxyethylene polyoxypropylene group as modified group are particularly preferred because they show good properties as aqueous surfactants.In addition, polyether modified silicone surfactants can also be used as the silicone surfactant, such as a compound in which a polyalkylene oxide structure is introduced into the Si part side chain of dimethylsiloxane.

[0038] As the fluorosurfactant, for example, perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chain are particularly preferred because they have low foaming properties. As the perfluoroalkyl sulfonic acid compounds, for example, perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, etc. are included. As the perfluoroalkyl carboxylic acid compounds, for example, perfluoroalkyl carboxylic acid, perfluoroalkyl carboxylate, etc. are included. As the polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chain, for example, sulfate ester salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups on the side chains, salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups on the side chains, etc. are included. As counter ions of the salts in these fluorosurfactants, Li, Na, K, NH4, NH3CH2CH2OH, NH2(CH2CH2OH)2, NH(CH2CH2OH)3, etc. are included. Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine. Examples of nonionic surfactants include polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene propylene block polymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and ethylene oxide adducts of acetylene alcohol. Examples of the anionic surfactant include polyoxyethylene alkyl ether acetates, dodecylbenzene sulfonates, laurates, and polyoxyethylene alkyl ether sulfates. These may be used alone or in combination of two or more.

[0039] The silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the silicone surfactant include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and both-end side-chain modified polydimethylsiloxane. Polyether-modified silicone surfactants having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group are particularly preferred because they exhibit good properties as an aqueous surfactant. Such surfactants may be appropriately synthesized or commercially available products, such as those available from BYK-Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Dow Corning Toray Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd. The polyether-modified silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be one in which a polyalkylene oxide structure is introduced into the Si part side chain of dimethylpolysiloxane, as represented by the following general formula (S-1).

[0040] [ka] (In the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R' represents an alkyl group.)

[0041] As the polyether-modified silicone surfactant, commercially available products can be used, such as KF-618, KF-642, KF-643 (manufactured by Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX (manufactured by Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (manufactured by Dow Corning Toray Silicone Co., Ltd.), BYK-33, BYK-387 (manufactured by BYK-Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (manufactured by Toshiba Silicon Co., Ltd.), and the like.

[0042] The fluorine-based surfactant is preferably a compound having 2 to 16 fluorine-substituted carbon atoms, and more preferably a compound having 4 to 16 fluorine-substituted carbon atoms. Examples of the fluorine-based surfactant include perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chains. Among these, polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chains are preferred because they have low foaming properties, and fluorine-based surfactants represented by any of general formulas (F-1) and (F-2) are particularly preferred.

[0043] [ka] In the compound represented by the above general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility.

[0044] [General formula (F-2)] C n F 2n+-CH2CH(OH)CH2-O-(CH2CH2O) a -Y In the compound represented by the above general formula (F-2), Y is H or C m F 2m+1 m is an integer from 1 to 6, or CH2CH(OH)CH2-C m F 2m+1 m is an integer of 4 to 6, or C p H 2P+1 where p is an integer from 1 to 19. n is an integer from 1 to 6. a is an integer from 4 to 14.

[0045] The fluorine-based surfactant may be a commercially available product. Examples of the commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, and FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F-1405, and F-474 (all manufactured by DIC Corporation); and Zonyl TBS, FSP, FSA, and FSN-100. , FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by Chemours); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omnova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.), and the like. Among these, FS-3100, FS-34, and FS-300 manufactured by Chemours Corporation, FT-110, FT-250, FT-251, FT-400S, FT-150, and FT-400SW manufactured by Neos Co., Ltd., Polyfox PF-151N manufactured by Omnova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferred, as they provide good printing quality, particularly improved color development, penetration into paper, wettability, and dye uniformity.

[0046] The content of the surfactant is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of improving wettability and image quality, the content is preferably from 0.01% by mass to 5% by mass, and more preferably from 0.05% by mass to 5% by mass, based on the total amount of the curable composition.

[0047] - Defoaming agent - The defoaming agent is not particularly limited, and examples thereof include silicone-based defoaming agents, polyether-based defoaming agents, and fatty acid ester-based defoaming agents. These may be used alone or in combination of two or more. Among these, silicone-based defoaming agents are preferred because of their excellent foam breaking effect.

[0048] -Preservative and fungicidal agent- The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

[0049] -Rust inhibitor- The rust inhibitor is not particularly limited, and examples thereof include acid sulfite, sodium thiosulfate, and 1,2,3-benzotriazole.

[0050] -pH adjuster- There are no particular limitations on the pH adjuster, so long as it is capable of adjusting the pH to 7 or higher, and examples of the pH adjuster include amines such as diethanolamine and triethanolamine, and 2-amino-2-ethyl-1,3-propanediol.

[0051] <Preparation of Curable Composition> The curable composition of the present invention can be prepared using the various components described above. The preparation means and conditions are not particularly limited. For example, the composition can be prepared by putting a trifunctional or higher polymerizable monomer, a pigment, a dispersant, etc. into a dispersing machine such as a ball mill, a Kitty mill, a disk mill, a pin mill, or a Dyno mill, dispersing the monomers to prepare a pigment dispersion, and further mixing a polymerizable monomer, a polymerization initiator, a polymerization inhibitor, a surfactant, etc. into the pigment dispersion.

[0052] <Viscosity> The viscosity of the curable composition of the present invention may be adjusted appropriately depending on the application and application means, and is not particularly limited. For example, when applying an ejection means for ejecting the composition from a nozzle, the viscosity in the range of 20°C to 65°C, desirably the viscosity at 25°C is preferably 3 mPa·s to 40 mPa·s, more preferably 5 mPa·s to 15 mPa·s, and particularly preferably 6 mPa·s to 12 mPa·s. It is particularly preferable that the viscosity range is satisfied without containing the organic solvent. The viscosity can be measured by using a cone-plate type rotational viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd., using a cone rotor (1°34'×R24), with a rotation speed of 50 rpm and a temperature of the constant temperature circulating water appropriately set in the range of 20°C to 65°C. A VISCOMATE VM-150III can be used to adjust the temperature of the circulating water.

[0053] <Application step and application means> The application step is a step of applying a curable composition containing water and a polymerizable compound onto a recording medium, and is carried out by an application means.

[0054] As the application means, various methods can be used, but the inkjet method is preferred. Known inkjet methods include the line head method and the serial head method. In the line head method, the main scanning direction is handled by moving the recording medium, and in the sub-scanning direction, the head is arranged in a line, the recording medium is continuously moved, and ink is ejected onto the recording medium from the recording head held at a fixed position to form an image. In the serial head method, the recording head is moved back and forth in the main scanning direction, which is the direction in which the nozzles are arranged side by side, and scanning in the sub-scanning direction is handled by moving the recording medium. In both methods, the recording head relatively scans the recording medium to eject liquid.

[0055] Other inkjet head types are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include continuous ejection type, on-demand type, etc. On-demand types include piezo type, thermal type, electrostatic type, etc., but the piezo type is preferred from the viewpoint of ejection reliability.

[0056] -Recording media- The recording medium used in the present invention is not particularly limited, but includes plain paper, glossy paper, special paper, cloth, film, OHP sheet, general-purpose printing paper, etc. Furthermore, it is not limited to those used as general inkjet recording media, and can be appropriately selected and used, such as cardboard, building materials such as wallpaper and flooring, concrete, cloth for clothing such as T-shirts, textiles, leather, etc.

[0057] <Active energy ray irradiation step and active energy ray irradiation means> This is a step of irradiating the recording medium to which the curable composition has been applied with active energy rays, and is carried out by active energy ray irradiation means.

[0058] The active energy ray may be any ray capable of imparting the energy required for promoting the polymerization reaction of the polymerizable component in the curable composition, such as ultraviolet rays, electron beams, α rays, β rays, γ rays, and X-rays, and is not particularly limited. However, from the viewpoint of curability, it is preferable to use ultraviolet rays. In addition, in the case of ultraviolet irradiation, mercury-free irradiation is strongly desired from the viewpoint of environmental protection, and replacement with GaN-based semiconductor ultraviolet light-emitting devices is very useful industrially and environmentally. Furthermore, ultraviolet light-emitting diodes (UV-LEDs) and ultraviolet laser diodes (UV-LDs) are small, have a long life, are highly efficient, and are low cost, and are therefore preferable as ultraviolet light sources.

[0059] Examples of the ultraviolet light source used as the curing means include low pressure mercury lamps, high pressure mercury lamps, metal halide lamps, hot cathode tubes, cold cathode tubes, LEDs, etc., but it is preferable to use a metal halide lamp because it is effective as a light source for curing the curable composition due to its wide wavelength range. As the metal halide, a metal halide such as Pb, Sn, Fe, etc. is used, and it can be appropriately selected according to the absorption spectrum of the photopolymerization initiator. Any lamp that is effective for curing can be used without particular limitations. In the case of a UV irradiation lamp, heat is generated, which may cause deformation of the recording medium, so it is preferable that a cooling mechanism, such as a cold mirror, a cold filter, or work cooling, is provided.

[0060] TIFF0007622395000003.tif77The illuminance of the metal halide lamp is set to 0.1 W / cm from the viewpoint of curing. 2 More than 150W / cm 2 In addition, when used for curing ink, the integrated amount of UV-A light is preferably 100 mJ / cm2 or less. 2 More than 2,000mJ / cm 2 It is preferable to irradiate to a level of 200 mJ / cm or less. 2 More than 2,000mJ / cm 2 It is more preferable to irradiate so that the following is obtained:

[0061] <Drying process and drying means> The drying step is a step of bringing the irradiated recording medium into contact with a heatable rotating body and heating it, and is carried out by a drying means. The drying means is a heatable rotating body (heat roller). By using a heatable rotating body as the drying means, there is an advantage that drying can be performed with a small amount of heat. The surface temperature of the rotor is preferably 40°C or higher, and more preferably 40°C or higher and 100°C or lower.

[0062] <Other steps and other means> The other steps include, for example, a control step. The other means may be, for example, a control means.

[0063] The curable composition of the present invention can be used as an ink to form two-dimensional characters and images, and decorative coatings on various substrates, and can also be used as a material for three-dimensional modeling to form a three-dimensional image (three-dimensional object). This material for three-dimensional modeling can be used, for example, as a binder between powder particles used in a powder lamination method in which a three-dimensional modeling is performed by repeatedly curing and laminating a powder layer, or as a three-dimensional construction material (model material) or a support member (support material) used in an additive manufacturing method (photolithography) as shown in FIG. 2 or FIG. 3. FIG. 2 shows a method of discharging the curable composition of the present invention into a predetermined area, irradiating it with active energy rays to cure it, and sequentially laminating the cured layers to perform three-dimensional modeling (described in detail later), and FIG. 3 shows a method of irradiating an active energy ray 4 to a storage pool (container) 1 of the curable composition 5 of the present invention to form a cured layer 6 of a predetermined shape on a movable stage 3, and sequentially laminating the layers to perform three-dimensional modeling.

[0064] As a three-dimensional modeling apparatus for forming a three-dimensional object using the curable composition of the present invention, a known one can be used, and is not particularly limited. For example, the three-dimensional modeling apparatus may be one equipped with a means for storing, supplying, and discharging the composition, and an active energy ray irradiation means. The present invention also includes a molded article obtained by processing a cured product obtained by curing the curable composition or a structure formed on a substrate with the cured product. The molded article is, for example, a product obtained by subjecting a cured product or structure formed into a sheet or film shape to molding such as heat stretching or punching, and is suitable for use in applications that require molding after surface decoration, such as meters and operation panels for automobiles, office automation equipment, electric and electronic devices, and cameras. The substrate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the substrate include paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, and composite materials thereof. From the viewpoint of processability, a plastic substrate is preferred.

[0065] (Containment Container) The container of the present invention means a container in which the curable composition is contained, and is suitable for the above-mentioned applications. For example, when the curable composition of the present invention is used for ink, the container containing the ink can be used as an ink cartridge or ink bottle, which eliminates the need to directly touch the ink during ink transport, ink replacement, and other operations, and can prevent the staining of hands, fingers, and clothing. In addition, it is possible to prevent the inclusion of foreign matter such as dust in the ink. In addition, the shape, size, material, and the like of the container itself may be suitable for the application and usage, and are not particularly limited, but it is preferable that the material is a light-shielding material that does not transmit light, or that the container is covered with a light-shielding sheet or the like.

[0066] (Two-dimensional or three-dimensional image forming device and two-dimensional or three-dimensional image forming method) The two-dimensional or three-dimensional image forming method of the present invention may use active energy rays or heating. In order to cure the curable composition of the present invention with active energy rays, an irradiation step of irradiating active energy rays is provided, and the two-dimensional or three-dimensional image forming apparatus of the present invention includes an irradiation means for irradiating active energy rays and a storage section for storing the curable composition of the present invention, and the storage section may store the container. Furthermore, the apparatus may include a discharge step and a discharge means for discharging the curable composition. The method of discharging is not particularly limited, and examples thereof include a continuous spray type and an on-demand type. Examples of the on-demand type include a piezo type, a thermal type, and an electrostatic type.

[0067] FIG. 1 is an example of a two-dimensional or three-dimensional image forming apparatus equipped with an inkjet ejection means. The ink is ejected onto a recording medium 22 supplied from a supply roll 21 by color printing units 23a, 23b, 23c, and 23d equipped with ink cartridges and ejection heads for yellow, magenta, cyan, and black curable inks. After that, the ink is cured by irradiating it with active energy rays from light sources 24a, 24b, 24c, and 24d for curing the ink, forming a color image. After that, the recording medium 22 is transported to a drying unit 25 and a print winding roll 26. Each printing unit 23a, 23b, 23c, and 23d may be provided with a heating mechanism so that the ink is liquefied in the ink ejection section. If necessary, a mechanism for cooling the recording medium to about room temperature by contact or non-contact may be provided. In addition, the inkjet recording method can be either a serial method in which the head is moved to eject ink onto the recording medium, which moves intermittently according to the width of the ejection head, or a line method in which the recording medium is moved continuously and ink is ejected onto the recording medium from a head held at a fixed position. The drying unit 25 is composed of a drying roller heated by a heater, a pressure roller that is in sliding contact with the fixing roller, and a thermistor (not shown) that detects the temperature of the drying roller. The recording medium 22 is not particularly limited, but may be paper, film, ceramics, glass, metal, a composite material thereof, or the like, and may be in the form of a sheet. The recording medium 22 may be configured to allow only one-sided printing, or may be configured to allow both-sided printing. The recording medium 22 is not limited to those generally used as recording media, and may be appropriately made of cardboard, building materials such as wallpaper and flooring, concrete, cloth for clothing such as T-shirts, textiles, leather, or the like. Furthermore, the irradiation of active energy rays from the light sources 24a, 24b, and 24c may be weakened or omitted, and after printing multiple colors, the active energy rays may be irradiated from the light source 24d, which can save energy and reduce costs.

[0068] Recorded items recorded with the curable composition of the present invention include not only those printed on smooth surfaces such as ordinary paper or resin films, but also those printed on uneven printing surfaces and those printed on printing surfaces made of various materials such as metals and ceramics. In addition, by laminating two-dimensional images, it is also possible to form an image with a partially three-dimensional effect (an image consisting of two and three dimensions) or a three-dimensional object.

[0069] Fig. 2 is a schematic diagram showing an example of another two-dimensional or three-dimensional image forming apparatus (three-dimensional solid image forming apparatus) according to the present invention. The three-dimensional solid image forming apparatus 39 in Fig. 2 uses a head unit (movable in the AB direction) in which inkjet heads are arranged, and ejects a first curable composition from a modeling object ejection head unit 30 and a second curable composition having a different composition from the first curable composition from support ejection head units 31 and 32, and laminates these compositions while curing them with adjacent ultraviolet ray irradiation means 33 and 34. More specifically, for example, the second curable composition is discharged from the support discharge head units 31 and 32 onto the object support substrate 37, and the first support layer having a reservoir is formed by irradiating the second curable composition with active energy rays to solidify the composition, and then the first curable composition is discharged from the object discharge head unit 30 into the reservoir and irradiated with active energy rays to solidify the composition to form a first object layer. This process is repeated several times while lowering the stage 38 movable in the vertical direction according to the number of layers to be stacked, thereby stacking the support layer and the object layer to produce a three-dimensional object 35. Thereafter, the support layer 36 is removed as necessary. Note that, although only one object discharge head unit 30 is provided in FIG. 2, two or more object discharge head units 30 may be provided.

[0070] (curable ink) The curable ink of the present invention comprises the curable composition of the present invention.

[0071] (cured product) The cured product of the present invention is formed using at least one of the curable composition of the present invention and the curable ink of the present invention.

[0072] In the present invention, the terms image formation, recording, printing, printing, etc. are all synonymous. Recording medium, media, and printed material are all synonymous. EXAMPLES

[0073] Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following examples, examples in which a curable ink is used as the curable composition will be described.

[0074] (Pigment Dispersion Preparation Example 1) -Preparation of cyan pigment dispersion- After thoroughly replacing the air in a 1 L flask equipped with a mechanical stirrer, a thermometer, a nitrogen gas inlet tube, a reflux condenser, and a dropping funnel, 11.2 parts by mass of styrene, 2.8 parts by mass of acrylic acid, 12.0 parts by mass of lauryl methacrylate, 4.0 parts by mass of polyethylene glycol methacrylate, 4.0 parts by mass of styrene macromer (manufactured by Toagosei Co., Ltd.), and 0.4 parts by mass of mercaptoethanol were mixed and heated to 65°C.

[0075] Next, a mixed solution of 100.8 parts by mass of styrene, 25.2 parts by mass of acrylic acid, 108.0 parts by mass of lauryl methacrylate, 36.0 parts by mass of polyethylene glycol methacrylate, 60.0 parts by mass of hydroxylethyl methacrylate, 36.0 parts by mass of styrene macromer (manufactured by Toagosei Co., Ltd.), 3.6 parts by mass of mercaptoethanol, 2.4 parts by mass of azobismethylvaleronitrile, and 18 parts by mass of methyl ethyl ketone was dropped into the flask over 2.5 hours. After the dropwise addition, a mixed solution of 0.8 parts by mass of azobismethylvaleronitrile and 18 parts by mass of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 parts by mass of azobismethylvaleronitrile was added and aged for another 1 hour. After the reaction was completed, 364 parts by mass of methyl ethyl ketone was added to the flask to obtain 800 parts by mass of polymer solution A having a concentration of 50% by mass.

[0076] Next, 28 parts by mass of the obtained polymer solution A, 26 parts by mass of phthalocyanine pigment (Dainichi Seika Chemicals Co., Ltd., Chromofine Blue A-220JC), 13.6 parts by mass of 1 mol / L potassium hydroxide aqueous solution, 20 parts by mass of methyl ethyl ketone, and 13.6 parts by mass of ion-exchanged water were thoroughly stirred, and then kneaded using a roll mill to obtain a paste. The obtained paste was added to 200 parts by mass of pure water, thoroughly stirred, and then methyl ethyl ketone and water were distilled off using an evaporator. Furthermore, in order to remove coarse particles, the dispersion was pressure-filtered with a polyvinylidene fluoride membrane filter with an average pore size of 5.0 μm to obtain a pigment-containing polymer microparticle dispersion containing 15% by mass of pigment and 20% by mass of solids. The cumulative 50% volume particle diameter (D 50 ) was measured using a particle size distribution analyzer (Nanorac UPA-EX150, manufactured by Nikkiso Co., Ltd.) and found to be 56.0 nm.

[0077] (Curable ink manufacturing example 1) -Production of curable ink 1- The organic solvent and water shown in Table 1-1 below were mixed and stirred for 1 hour to obtain a uniform mixture. A polymerizable compound was added and stirred for 1 hour, and then a pigment dispersion, a polymerization initiator, an antifoaming agent, and a pH adjuster were added and stirred for 1 hour. The resulting dispersion was pressure-filtered through a polyvinylidene fluoride membrane filter with an average pore size of 5.0 μm to remove coarse particles and dust, producing curable ink 1.

[0078] (Curable ink manufacturing examples 2 to 12) -Manufacture of curable inks 2 to 12- Curable inks 2 to 12 were obtained in the same manner as in curable ink production example 1, except that the compositions in curable ink production example 1 were changed to those shown in Tables 1-1 and 1-2.

[0079] [Table 1-1]

[0080] [Table 1-2]

[0081] Details of each component listed in Tables 1-1 and 1-2 are as follows. -Polymerizable compound- 4-Hydroxybutyl acrylate (monofunctional) (Tokyo Chemical Industry Co., Ltd.), solubility in water at 25°C is infinite (∞) g / 100 g water N,N'-methylenebisacrylamide (bifunctional) (Tokyo Chemical Industry Co., Ltd.), solubility in water at 25°C is infinite (∞) g / 100 g water Ethoxylated glycerin triacrylate (20 mol addition) (3 functional groups) (manufactured by Shin-Nakamura Chemical Co., Ltd.), solubility in water at 25°C is 22 g / 100 g water Ethoxylated pentaerythritol tetraacrylate (35 mol added) (EO35 mol) (4 functional groups) (manufactured by Shin-Nakamura Chemical Co., Ltd.), solubility in water at 25°C is 15 g / 100 g water Polyglycerol acrylate (6 functional groups) (manufactured by Sakamoto Pharmaceutical Co., Ltd.), solubility in water at 25°C is 18g / 100g water

[0082] -Surfactants- Surfynol 440: Acetylene glycol surfactant (manufactured by Nissin Chemical Industry Co., Ltd.)

[0083] (Examples 1 to 10, Comparative Examples 1 to 7, and Reference Examples 1 to 4) Next, images were formed under the conditions below using the curable inks 1 to 12 obtained as shown in Table 2, and the drying properties were evaluated as follows. The results are shown in Table 2.

[0084] <Image formation> A single-pass type printing apparatus 100 equipped with a head MH5220 manufactured by Ricoh Co., Ltd. as shown in FIG. 4 was manufactured, and a solid image chart was printed. In the printing device 100, a head unit 101, an ultraviolet (UV) irradiation device 102, and a drying device 103 are fixed in this order, and are controlled so that a recording medium 105 can be conveyed under each unit at an arbitrary conveying speed. The UV irradiation device 102 is equipped with Subzero085 manufactured by Integration Technology, and is capable of UV irradiation while printing. 2 Two lamps are used at an illuminance of 300 mJ / cm2. 2 The irradiation was performed so that A metal roller driven by a recording medium having a diameter of 20 mm and controlled so as to be able to be heated to any surface temperature (see Table 2) by a thermocouple was installed as the drying device 103. The load of the metal roller on the recording medium was 0.76 N. Printing conditions were head gap 2 mm, ejection volume per droplet 4 pL, 1200 dpi, and ink deposition volume 8.9 g / m 2 The printing was performed under the above conditions, and the image pattern was a solid image of 5 cm x 20 cm. The distance from the end of the head unit to the UV irradiation device is 400 mm. The distance from the end of the head unit to the drying device is 1,200 mm.

[0085] <Drying> Using each curable ink, a white cotton cloth (Kanakin No. 3) was attached around the driven metal roller of the drying device, and an image formed under the above printing conditions was immediately printed under the above printing conditions using the above printing device. After printing, the state of ink adhesion to the cotton cloth was observed and evaluated according to the following criteria. The results are shown in Table 2. [Evaluation Criteria] A: No ink residue even when observed with a 10x loupe B: No ink is found when observed with the naked eye, but ink is found on the cotton fabric fibers when observed with a 10x loupe C: Image transferred to roller

[0086] [Table 2]

[0087] For example, aspects of the present invention are as follows. <1> An application step of applying a curable composition containing water and a polymerizable compound onto a recording medium; an active energy ray irradiation step of irradiating the recording medium to which the curable composition has been applied with active energy ray irradiation; A drying step of heating the irradiated recording medium by contacting it with a heatable rotating body, The polymerizable compound contains a trifunctional or higher functional polymerizable compound, The image forming method is characterized in that the content of the water is greater than the content of the polymerizable compound. <2> The trifunctional or higher polymerizable compound has a solubility in water of 10 g / 100 g of water or more at 25° C. <1> 2. The image forming method according to claim 1 . <3> The surface temperature of the rotating body is 40° C. or higher. <1> from <2> 13. The image forming method according to claim 12, wherein <4> The content of the trifunctional or higher polymerizable compound is 5% by mass or more and 15% by mass or less. <1> from <3> 13. The image forming method according to claim 12, wherein <5> The curable composition contains a polymerization initiator. <1> from <4> 13. The image forming method according to claim 12, wherein <6> An applying means for applying a curable composition containing water and a polymerizable compound onto a recording medium; a curing means for irradiating the recording medium to which the curable composition has been applied with active energy rays (ultraviolet rays); a drying means for contacting a rotating body with the heatable recording medium having the cured image thereon and heating the recording medium, The polymerizable compound includes a trifunctional or higher functional polymerizable compound. The image forming apparatus is characterized in that the content of the water is greater than the content of the polymerizable compound. <7> Contains water, a polymerizable compound, and a polymerization initiator; The polymerizable compound contains a trifunctional or higher functional polymerizable compound, The curable composition is characterized in that the content of the water is greater than the content of the polymerizable compound. <8> The trifunctional or higher polymerizable compound has a solubility in water of 10 g / 100 g of water or more at 25° C. <7> The curable composition according to claim 1, <9> The content of the trifunctional or higher polymerizable compound is 5% by mass or more and 15% by mass or less. <7> from <8> The curable composition according to any one of claims 1 to 5, <10> The curable composition is an active energy ray curable composition. <7> from <9> The curable composition according to any one of claims 1 to 5, <11> The above <7> from <10> 2. A curable ink comprising the curable composition according to claim 1. <12> The above <7> from <10> 1. A storage container comprising the curable composition according to any one of the above items stored in the container. <13> The above <11> A storage section that stores the curable ink according to the above item, An irradiation means for irradiating with active energy rays; The present invention relates to a two-dimensional or three-dimensional image forming apparatus. <14> The ink jet recording medium further includes a discharge unit that discharges the curable ink by an ink jet method. <13> The two-dimensional or three-dimensional image forming apparatus according to the present invention is <15> The above <11> An application step of applying the curable ink described in an irradiation step of irradiating the applied curable ink with active energy rays; A method for forming a two-dimensional or three-dimensional image, comprising: <16> The above <7> from <10> The curable composition according to any one of the preceding claims, <11> and a cured product formed by using at least one of the curable inks described above.

[0088] The above <1> from <5> The image forming method according to any one of the preceding claims. <6> The image forming apparatus according to the <7> from <10> The curable composition according to any one of the preceding claims. <11> The curable ink according to <12> The container according to <13> from <14> The two-dimensional or three-dimensional image forming apparatus according to any one of the preceding claims. <15> The two-dimensional or three-dimensional image forming method according to claim 1, <16> According to the cured product described in the above, the conventional problems can be solved and the object of the present invention can be achieved. [Explanation of symbols]

[0089] 1. Storage pool (containment area) 3 Movable stage 4. Active energy rays 5. Active energy ray-curable composition 6 Hardened layer 21 Supply roll 22 Recording media 23a, 23b, 23c, 23d Printing units 24a, 24b, 24c, 24d light source 25 Processing Unit 26 Printed matter winding roll 30. Discharge head unit for modeling 31, 32 Support ejection head unit 33, 34 Ultraviolet irradiation means 35 Three-dimensional sculpture 36 Support layer section 37 Object support substrate 38 Stages 39 Image forming device [Prior art documents] [Patent documents]

[0090] [Patent Document 1] JP 2018-83352 A

Claims

1. An application step of applying a curable composition containing water and a polymerizable compound onto a recording medium; an active energy ray irradiation step of irradiating the recording medium to which the curable composition has been applied with active energy ray irradiation; A drying step of drying the irradiated recording medium by contacting the irradiated recording medium with a heatable rotating body, the polymerizable compound contains a tri- or higher functional polymerizable compound, the content of the water is greater than the content of the polymerizable compound, The surface temperature of the rotating body is 42° C. or higher and 100° C. or lower, The image forming method, wherein the tri- or higher functional polymerizable compound contains at least one of ethoxylated glycerin triacrylate, ethoxylated pentaerythritol tetraacrylate, and polyglycerin acrylate.

2. The image forming method according to claim 1 , wherein the tri- or higher functional polymerizable compound has a solubility in water at 25° C. of 10 g / 100 g water or more.

3. The image forming method according to claim 1 , wherein the content of the tri- or higher functional polymerizable compound is from 5% by mass to 15% by mass.

4. The image forming method according to claim 1 , wherein the curable composition contains a polymerization initiator.

5. An applying means for applying a curable composition containing water and a polymerizable compound onto a recording medium; a curing means for irradiating the recording medium to which the curable composition has been applied with ultraviolet light; a drying means for drying the recording medium after irradiation by bringing a heatable rotating body into contact with the recording medium, the polymerizable compound contains a tri- or higher functional polymerizable compound, the content of the water is greater than the content of the polymerizable compound, The surface temperature of the rotating body is 42° C. or higher and 100° C. or lower, The image forming apparatus according to the present invention, wherein the tri- or higher functional polymerizable compound contains at least one of ethoxylated glycerin triacrylate, ethoxylated pentaerythritol tetraacrylate, and polyglycerin acrylate.

Images