Ink composition, ink set, printed matter, inkjet recording device, recording method, and method for producing printed matter

Abstract

To provide an active energy ray-curable ink composition capable of forming a cured film of the ink composition having adhesion to various substrates.SOLUTION: The active energy ray-curable ink composition to be discharged by an inkjet method contains a polymerizable compound. The polymerizable compound contains a polymerizable compound represented by the following general formula (1) (where R1 represents hydrogen or a methyl group; R2 represents hydrogen or a C1-10 optionally branched alkyl group; and R3 represents hydrogen or a C1-10 optionally branched alkyl group).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an ink composition, an ink set, a printed matter, an inkjet recording apparatus, a recording method, and a method for producing a printed matter. [Background technology]

[0002] In recent years, the trend toward small-lot, diversified printing of printed matter has progressed, and inkjet printing, which is an on-demand printing method, has been attracting attention as an alternative to conventional offset printing. Inkjet printing is simpler than conventional offset printing, and has the advantages of being more economical and energy-saving.

[0003] Among such inkjet printing methods, there is an active energy ray curable ink composition that is cured by ultraviolet light, electron beams, or other active energy rays. Since the active energy ray curable ink composition dries quickly, it is possible to prevent the ink from bleeding even when printing on a substrate that does not absorb ink or absorbs ink very little, such as plastic, glass, or coated paper.

[0004] For example, Patent Document 1 describes an active energy ray-curable ink that is characterized by containing a polymerizable compound having a specific structure. Patent Document 1 also describes that this active energy ray-curable ink has excellent adhesion to polycarbonate substrates and vinyl chloride substrates.

[0005] Patent Document 2 describes an active energy ray-curable ink that contains a polymerizable compound having a specific structure. Patent Document 2 describes that this active energy ray-curable ink can form an image that has excellent adhesion and abrasion resistance over time to polyvinyl chloride building materials. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2023-080137 [Patent Document 2] WO2020 / 174783 Summary of the Invention [Problem to be solved by the invention]

[0007] An active energy ray-curable ink composition discharged by an inkjet method is required to form a cured film having high adhesion to various substrates such as substrates of flexible polyvinyl chloride resins and substrates of hard acrylic resins.

[0008] An object of the present invention is to provide an active energy ray-curable ink composition capable of forming a cured film having adhesion to various substrates. [Means for solving the problem]

[0009] As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by an ink composition containing a specific polymerizable compound, and have completed the present invention. Specifically, the present invention provides the following.

[0010] (1) An active energy ray-curable ink composition that is ejected by an inkjet method, the ink composition containing a polymerizable compound represented by the following general formula (1): [ka] (In the formula, R 1 is hydrogen or a methyl group, and R 2 is hydrogen or an alkyl group having 1 to 10 carbon atoms which may be branched, and R 3 is hydrogen or an alkyl group having 1 to 10 carbon atoms, which may be branched.

[0011] (2) The ink composition according to (1), wherein the polymerizable compound represented by general formula (1) is liquid at 20° C. under 1 atmospheric pressure.

[0012] (3) The ink composition according to (2), wherein the polymerizable compound represented by general formula (1) has a vapor pressure at 20° C. of 60 Pa or less.

[0013] (4) R in general formula (1) 1 R 2 R 3 The ink composition according to (1) or (2), wherein the total number of carbon atoms contained in

[0014] (5) The ink composition according to (1) or (2), further comprising a binder resin having a weight average molecular weight of 10,000 or more, the content of the binder resin being 0.05% by mass or more and 25% by mass or less based on the total amount of the ink composition.

[0015] (6) The ink composition according to (1) or (2), wherein the polymerizable compound contains a polyfunctional polymerizable compound, and the polyfunctional polymerizable compound having 4 or more functional groups accounts for 25 mass % or less of the total amount of the ink composition.

[0016] (7) The ink composition according to (6), wherein the total content of the binder resin and the polyfunctional polymerizable compound having 4 or more functional groups is 30 mass % or less of the total amount of the ink composition.

[0017] (8) The ink composition according to (1) or (2), which contains a colorant and may further contain a dispersant that disperses the colorant, and in the case where the dispersant is contained, the content of the dispersant is less than the content of the colorant.

[0018] (9) The ink composition according to (1) or (2), which is cured by active energy rays irradiated from an LED lamp.

[0019] (10) An ink set comprising the ink composition according to (1) or (2).

[0020] (11) A printed matter having the ink composition according to (1) or (2) printed thereon.

[0021] (12) An ink jet recording device comprising a storage mechanism filled with the ink composition according to (1) or (2).

[0022] (13) A recording method comprising ejecting the ink composition according to (1) or (2) by an ink-jet method.

[0023] (14) A printed matter is produced by ejecting the ink composition according to (1) or (2) by an inkjet method. A method for producing printed matter. Effect of the Invention

[0024] The active energy ray-curable ink composition of the present invention can form a cured film of the ink composition that has adhesion to various substrates. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Specific embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments and can be modified as appropriate within the scope of the object of the present invention.

[0026] 1. Active energy ray-curable ink composition The active energy ray-curable ink composition according to this embodiment contains a polymerizable compound, and is characterized by containing a polymerizable compound represented by the following general formula (1).

[0027] [ka] (In the formula, R 1 is hydrogen or a methyl group, and R 2 is hydrogen or an alkyl group having 1 to 10 carbon atoms which may be branched, and R 3is hydrogen, an alkyl group having 1 to 10 carbon atoms which may be branched, or an alkyl group having 1 to 10 carbon atoms which contains a functional group and may be branched.

[0028] An active energy ray-curable ink composition that is cured by active energy rays is sometimes required to form a cured film with good adhesion to various substrates such as a film substrate of a flexible polyvinyl chloride resin, an acrylic resin having high hardness, etc. In particular, an acrylic resin substrate is a substrate having a relatively high hardness and transparency, and is used in a wide range of applications, but there has been a problem in that it is difficult to form a cured film of the ink composition having sufficient adhesion.

[0029] However, surprisingly, the present inventors have found through their research that the active energy ray-curable ink composition according to this embodiment, which contains a predetermined amount of the polymerizable compound represented by general formula (1) as the polymerizable compound, can form a cured film having good adhesion to various substrates such as acrylic resins having high hardness.

[0030] Since the polymerizable compound represented by the general formula (1) has an amide group, intermolecular interactions such as hydrogen bonds occur between the compounds, and the intermolecular distance tends to become short. This makes it easy for the polymerizable compound represented by the general formula (1) to undergo polymerization reaction, and as a result, it becomes possible to form a cured film that has adhesion to various substrates.

[0031] The active energy ray-curable ink composition according to this embodiment may contain a polymerization initiator as an optional component. However, if a polymerization initiator that is not a candidate for inclusion as a substance of very high concern (SVHC) in Annex XIV of the REACH regulation enacted by the European Union is used as this polymerization initiator, the curability of the active energy ray-curable ink composition may be relatively decreased compared to a case in which a polymerization initiator that is a candidate for inclusion as a substance of very high concern is used.

[0032] However, in the case of an active energy ray-curable ink composition containing a predetermined amount of a polymerizable compound represented by general formula (1), it is possible to suppress a decrease in the curability of the ink composition even if a polymerization initiator that is relatively likely to decrease the curability of the ink composition is used.

[0033] The actinic ray-curable ink composition according to the present embodiment may be a colored ink containing a coloring material. In this specification, the term "coloring material" includes dyes and pigments, and is used as a concept including, for example, dyes or pigments contained in colored inks that form images of yellow, magenta, cyan, black, red, orange, violet, blue, green, and intermediate or light colors thereof, white dyes or white pigments contained in white inks, and glittering coloring materials contained in metallic inks.

[0034] The color ink may be a color ink that forms an image in yellow, magenta, cyan, black, red, orange, violet, blue, green, or intermediate or light colors thereof. The color ink may be a white ink that contains a white coloring material, or a metallic ink that contains a glittering coloring material.

[0035] Furthermore, when the active energy ray-curable ink composition according to this embodiment contains a coloring material, the ink composition may contain a dispersant that disperses at least a part of the coloring material in the ink composition.

[0036] The active energy ray curable ink composition according to the present embodiment may be a clear ink that does not contain a coloring material. Specifically, it may be a primer ink for forming a primer layer on the surface of a substrate or the like, an overcoat ink for forming an overcoat layer on the surface of a recorded matter, a matte ink composition for removing the gloss of a recorded matter (substrate), an ink composition for imparting gloss (gloss) or texture, or an ink containing an ultraviolet absorber, a light stabilizer, or the like for forming a weather-resistant layer.

[0037] The water content in the active energy ray-curable ink composition according to this embodiment is preferably 5.0 mass % or less, more preferably 3.0 mass % or less, and even more preferably 1.0 mass % or less, of the total amount of the ink composition.

[0038] Hereinafter, each component contained in the actinic energy ray-curable ink composition according to this embodiment will be described.

[0039] [Polymerizable compound] The active energy ray curable ink composition according to the present embodiment contains a polymerizable compound. The polymerizable compound is a compound (polymerizable monomer) that has one or more ethylenically unsaturated double bonds and is polymerized to form a cured product by irradiation with active energy rays. The active energy rays include electromagnetic waves such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, visible light, infrared rays, X-rays, and gamma rays, as well as electron beams, proton beams, and neutron beams. This polymerizable compound is mainly liquid and has the function of forming a cured product by polymerization, and also has the function of serving as a dispersion medium or solvent for the ink composition.

[0040] The polymerizable compound may be a monofunctional polymerizable compound having one ethylenically unsaturated double bond in the compound, or a polyfunctional polymerizable compound having two or more ethylenically unsaturated double bonds in the compound.

[0041] The polymerizable compound may be a polymerizable compound having a relatively large weight average molecular weight, such as a polymerizable compound called an oligomer.

[0042] The polymerizable compound contained in the active energy ray-curable ink composition according to this embodiment contains a polymerizable compound represented by the following general formula (1).

[0043] [ka] (In the formula, R 1 is hydrogen or a methyl group, and R 2is hydrogen or an alkyl group having 1 to 10 carbon atoms which may be branched, and R 3 is hydrogen, an alkyl group having 1 to 10 carbon atoms which may be branched, or an alkyl group having 1 to 10 carbon atoms which contains a functional group and may be branched.

[0044] In addition, R 1 and R 2 and R 3 may be the same or different. 1 More preferably, R is hydrogen. 2 R is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which may be branched, more preferably an alkyl group having 2 to 4 carbon atoms, which may be branched, and even more preferably an alkyl group having 2 to 3 carbon atoms, which may be branched. 3 is preferably an alkyl group having 1 to 8 carbon atoms, which may be branched, or an alkyl group containing a functional group and having 2 to 6 carbon atoms, which may be branched, more preferably an alkyl group having 2 to 4 carbon atoms, which may be branched, and even more preferably an alkyl group having 2 to 3 carbon atoms, which may be branched.

[0045] Examples of the "functional group" in the alkyl group having 1 to 10 carbon atoms and which contains a functional group and may be branched include, but are not limited to, a hydroxy group, an alkoxy group, a carboxy group, a carbonyl group, an amino group, an imino group, a cyano group, an azo group, an acyl group, an acetyl group, a sulfo group, and a nitro group.

[0046] Examples of the polymerizable compound represented by the general formula (1) include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-ethyl-N-methyl-(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N-ethyl-N-butyl-acrylamide, N-isopropyl(meth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-octyl(meth)acrylamide, N-2-ethylhexyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-[3-(dimethylamino)propyl](meth)acrylamide, diacetone(meth)acrylamide, N-tert-butyl(meth)acrylamide, and N-(dibutylaminomethyl)(meth)acrylamide. The active energy ray-curable ink composition according to this embodiment may contain one type of polymerizable compound represented by general formula (1), or may contain multiple types of polymerizable compounds represented by general formula (1). Note that "(meth)acrylate" refers to both "acrylate" and "methacrylate".

[0047] The content of the polymerizable compound represented by the general formula (1) is not particularly limited, but is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, even more preferably 10% by mass or more, and even more preferably 15% by mass or more in the total amount of the ink composition. The content of the polymerizable compound represented by the general formula (1) is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, even more preferably 70% by mass or less, and even more preferably 60% by mass or less in the total amount of the ink composition. The content of the polymerizable compound represented by the general formula (1) is preferably 2% by mass or more and 90% by mass or less, more preferably 5% by mass or more and 80% by mass or less, even more preferably 8% by mass or more and 75% by mass or less, even more preferably 10% by mass or more and 70% by mass or less, and even more preferably 15% by mass or more and 60% by mass or less in the total amount of the ink composition.

[0048] By the content of the polymerizable compound represented by the general formula (1) being within the above-mentioned range, the solubility of the polymeric components such as resins and oligomers becomes good, and the polymeric components can act as components for imparting or improving the coating performance. Furthermore, by the content of the polymerizable compound represented by the general formula (1) being within the above-mentioned range, the ink composition can be made in which the components contained therein are kept stable.

[0049] In addition, by the content of the polymerizable compound represented by the general formula (1) being within the above-mentioned range, the solubility of the components contained in the ink composition, such as the polymerization initiator, the polymerization chain agent, and the additive, is improved, and the ink composition can be made to have good curing properties, ejection properties, and excellent coating properties. Compounds that are not candidates for inclusion as substances of high concern listed in Annex XIV of the REACH Regulation enacted by the European Union (described later, for example, polymerization initiators corresponding to the formulas (2) to (8) described later) may be difficult to dissolve in general polymerizable compounds, and may require a large amount of addition due to insufficient curing performance as a polymerization initiator, which may cause problems in maintaining the solubility in the ink composition in a good state. By the content of the polymerizable compound represented by the general formula (1) being within the above-mentioned range, it is possible to maintain the solubility in the ink composition in a good state while maintaining the curing performance as a polymerization initiator.

[0050] The polymerizable compound represented by the general formula (1) is preferably liquid at 20°C under 1 atmosphere. An active energy ray curable ink composition may be stored in a cool, dark place, and when the ink composition is stored in a refrigerator, the components contained in the ink composition (polymerization initiator, polymerization chain agent, antioxidant, ultraviolet absorber, stabilizer, pH adjuster, polymerization inhibitor, surfactant, dispersant, dispersion aid, resin, oligomer, and other components contained in the ink composition) may precipitate. Therefore, by the polymerizable compound represented by the general formula (1) being liquid at 20°C under 1 atmosphere, the volatilization of the polymerizable compound represented by the general formula (1) during storage can be suppressed, and the components contained in the ink composition can be suppressed from precipitating, making it possible to improve storage stability. In addition, the good solubility increases the fluidity of the ink composition inside the nozzle or inkjet head, making it possible to improve inkjet dischargeability. Furthermore, since the polymerizable compound represented by general formula (1) is liquid at 20°C under 1 atmosphere, the curability can be improved and separation or precipitation of solutes from the cured coating film can be suppressed. This makes it possible to obtain a uniform coating film and improve the physical properties of the coating film after curing of the ink composition.

[0051] Examples of the polymerizable compound represented by general formula (1) which is liquid at 20° C. under 1 atmosphere include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-ethyl-N-methyl-(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N-ethyl-N-butyl-acrylamide, N-isopropyl(meth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-octyl(meth)acrylamide, N-2-ethylhexyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-[3-(dimethylamino)propyl](meth)acrylamide.

[0052] The polymerizable compound represented by general formula (1) preferably has a vapor pressure of 60 Pa or less, more preferably 50 Pa or less, at 20° C. If the vapor pressure at 20° C. is high (high volatility), the ink composition may be easily dried in the vicinity of the nozzle, and components contained in the ink composition may precipitate in the vicinity of the nozzle, or the viscosity of the ink composition may become too high, resulting in poor inkjet dischargeability. However, if the vapor pressure at 20° C. is 60 Pa or less, more preferably 50 Pa or less, it is possible to suppress drying of the ink composition in the vicinity of the nozzle, precipitation of components contained in the ink composition, and an increase in the viscosity of the ink composition, thereby improving the inkjet dischargeability.

[0053] Examples of the polymerizable compound represented by general formula (1) having a vapor pressure of 60 Pa or less at 20° C. include N,N-diethyl(meth)acrylamide, N-ethyl-N-methyl-(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N-ethyl-N-butyl-acrylamide, N-isopropyl(meth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-octyl(meth)acrylamide, N-2-ethylhexyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-[3-(dimethylamino)propyl](meth)acrylamide.

[0054] R in the polymerizable compound represented by formula (1) 1 R 2 R 3 The total number of carbon atoms contained in R in the general formula (1) is preferably 3 or more, and more preferably 4 or more. 1 R 2 R 3 The upper limit of the total number of carbon atoms contained in is preferably 18 or less, more preferably 10 or less, and even more preferably 8 or less. By keeping it within this range, the above-mentioned effects can be made better.

[0055] R in the polymerizable compound represented by formula (1) 2 R 3 It is more preferable that both are alkyl groups. The storage stability of the ink composition is improved by the moderate acid-base interaction. In addition, by maintaining good solubility of the components contained in the ink composition (constituents contained in the ink composition such as polymerization initiators, polymerization chain agents, antioxidants, ultraviolet absorbers, stabilizers, pH adjusters, polymerization inhibitors, surfactants, dispersants, dispersion aids, resins, oligomers, etc.), the ink jet ejection properties can be improved, and further, a uniform coating film can be obtained.

[0056] The active energy ray-curable ink composition according to this embodiment may contain a polymerizable compound other than the polymerizable compound represented by general formula (1).

[0057] Examples of other monofunctional polymerizable compounds different from the polymerizable compound represented by general formula (1) include tetrahydrofurfuryl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) (meth)acrylate, (2-methyl-2-isobutyl-1,3-dioxolan-4-yl) (meth)acrylate, (cyclohexanespiro-2-(1,3-dioxolan-4-yl)) (meth)acrylate, and 4-t-butylcycloalkyl acrylate, which is an alkylcycloalkyl acrylate. Hexyl (meth)acrylate, n-butylcyclohexyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, gamma-butyrolactone (meth)acrylate, cresol (meth)acrylate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, 2-acryloyloxyethyl 2-Acryloyloxypropyl phthalate, para-cumylphenoxyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, 1-adamantyl (meth)acrylate, cyclohexyl (meth)acrylate, cyclooctyl (meth)acrylate, hydroxycyclohexyl (meth)acrylate, 3-3-5-trimethylcyclohexyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth), N-vinylpyrrole acrylate, acryloyloxypropyl phthalate, ylmorpholine, N-vinyl caprolactam, imide (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, stearyl (meth)acrylate, isodecyl (meth)acrylate, caprolactone (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, 2-methoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate,2-Ethylhexyl (meth)acrylate, vinylcyclohexane, tert-butyl-4-ethynylcyclohexane, cycloheptyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclobutyl (meth)acrylate, phenyl (meth)acrylate, styrene, N-vinylpyrrolidone, N-vinyloxazolidone, 2-vinyl-2-oxazoline N-vinylpyridine, N-vinylimidazole, 2-isopropenyl-2-oxazoline, methyl (meth)acrylate, butyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, octyl (meth)acrylate, trifluoroethyl (meth)acrylate, 3-hydroxy Propyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, methyl α-(hydroxymethyl) (meth)acrylate, ethyl α-(hydroxymethyl) (meth)acrylate, n-butyl α-(hydroxymethyl) (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, N-vinyl succinimide, N-vinyl methyl carbamate, N,N-methyl vinyl acetamide, (meth)acryloyloxyethyl trimethyl ammonium chloride, (meth)acrylonitrile, and acrylates having various modifications such as alkoxy modification and caprolactone modification can be mentioned. These other polymerizable compounds may be used alone or in combination of multiple polymerizable compounds. In addition, "(meth)acrylate" means both "acrylate" and "methacrylate".

[0058] Examples of other polyfunctional polymerizable compounds different from the polymerizable compound represented by general formula (1) include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, long-chain aliphatic di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,6-Hexanediol di(meth)acrylate modified with ethylene oxide (EO modified) (2), 1,6-Hexanediol di(meth)acrylate modified with ethylene oxide (EO modified) (3), 1,6-Hexanediol di(meth)acrylate modified with ethylene oxide (EO modified) (5), 1,6-Hexanediol di(meth)acrylate modified with propion oxide (PO modified) (2), 1,6-Hexanediol di(meth)acrylate modified with propion oxide and PO (PO modified) (3), 1,9-Nonandiol di(meth)acrylate acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide modified EO modified neopentyl glycol di(meth)acrylate (EO modified) (2), ethylene oxide modified EO modified neopentyl glycol di(meth)acrylate (EO modified) (3), propion oxide modified PO modified neopentyl glycol di(meth)acrylate (PO modified) (2), propion oxide modified PO modified neopentyl glycol di(meth)acrylate (PO modified) (8), propionate modified neopentyl glycol di(meth)acrylate PO modified (PO modified) (16), hydroxypivalic acid neopentyl glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate caprolactone modified (2), hydroxypivalic acid neopentyl glycol di(meth)acrylate caprolactone modified (4), polyalkylene glycol diacrylate, polyalkylene glycol diacrylate ethylene oxide modified (EO modified) (4), polyalkylene glycol diacrylate ethylene oxide modified (EO modified) (9),Ethylene oxide modified polyalkylene glycol diacrylates (EO modified) (14), Ethylene oxide modified polyalkylene glycol diacrylates (EO modified) (23), Ethylene oxide modified polyalkylene glycol diacrylates (EO modified) (46), Propion oxide modified polyalkylene glycol diacrylates (PO modified) (3), Propion oxide modified polyalkylene glycol diacrylates (PO modified) (7), Propion oxide modified polyalkylene glycol diacrylates (PO modified) (12), ethylene oxide and propion oxide modified polyalkylene glycol diacrylate (PO modified (12) & EO modified (6)), ethylene oxide and propion oxide modified polyalkylene glycol diacrylate (PO modified (6) & EO modified (12)), ethylene oxide and propion oxide modified polyalkylene glycol diacrylate (PO modified (4) & EO modified (12)), ethylene oxide and propion oxide modified polyalkylene glycol diacrylate ( PO modified (4) & EO modified (17)), ethylene oxide and propionate modified polyalkylene glycol diacrylates (PO modified (13) & EO modified (5)), butylene oxide modified polyalkylene glycol diacrylates (BO modified) (3.5), butylene oxide modified polyalkylene glycol diacrylates (BO modified) (9), butylene oxide modified polyalkylene glycol diacrylates (BO modified) (14), stearic acid modified pentaerythritol di(meth)acrylate, propylene Glycol di(meth)acrylate, glycerol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2-(2-vinyloxyethoxy)ethyl acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene di(meth)acrylate, triglycerol di(meth)acrylate,Neopentyl glycol modified trimethylolpropane di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, methoxylated cyclohexyl di(meth)acrylate, acrylated isocyanurate, bis(acryloxyneopentyl glycol) adipate, bisphenol A di(meth)acrylate, ethylene oxide modified (EO modified) bisphenol A di(meth)acrylate (2), ethylene oxide modified (EO modified) bisphenol A di(meth)acrylate (3), bisphenol A di(meth)acrylate (4), ethylene oxide modified (EO modified) of bisphenol A di(meth)acrylate (10), ethylene oxide modified (EO modified) of bisphenol A di(meth)acrylate (20), ethylene oxide modified (EO modified) of bisphenol A di(meth)acrylate (30), propion oxide modified (PO modified) of bisphenol A di(meth)acrylate (3), ethylene oxide and propion oxide modified (PO modified (6) & EO modified (3)), tetrabromobisphenol A di(meth)acrylate, bisphenol S di(meth)acrylate, butanediol di(meth)acrylate, phthalic acid di(meth)acrylate, phosphoric acid di(meth)acrylate, zinc di(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene oxide modified (EO modified) pentaerythritol tetra(meth)acrylate (4), ethylene oxide modified (EO modified) pentaerythritol tetra(meth)acrylate (35), pentaerythritol tetra(meth ) acrylate modified with propion oxide (PO modified) (4), pentaerythritol tetra(meth)acrylate modified with propion oxide (PO modified) (10), ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate modified with ethylene oxide (EO modified) (6), dipentaerythritol hexa(meth)acrylate modified with ethylene oxide (EO modified) (12),Dipentaerythritol hexa(meth)acrylate modified with ethylene oxide (EO modified) (18), dipentaerythritol hexa(meth)acrylate modified with ethylene oxide (EO modified) (24), dipentaerythritol hexa(meth)acrylate modified with ethylene oxide (EO modified) (48), dipentaerythritol hexa(meth)acrylate modified with propionate oxide (PO modified) (6), dipentaerythritol hexa(meth)acrylate modified with caprolactone (2), dipentaerythritol hexa(meth)acrylate modified with (3), caprolactone-modified dipentaerythritol hexa(meth)acrylate (6), caprolactone-modified dipentaerythritol hexa(meth)acrylate (12), trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate (3), ethylene oxide-modified trimethylolpropane tri(meth)acrylate (6), ethylene oxide-modified trimethylolpropane tri(meth)acrylate oxide modified (EO modified) (9), trimethylolpropane tri(meth)acrylate ethylene oxide modified (EO modified) (15), trimethylolpropane tri(meth)acrylate ethylene oxide modified (EO modified) (20), trimethylolpropane tri(meth)acrylate ethylene oxide modified (EO modified) (30), trimethylolpropane tri(meth)acrylate propionoxide modified (PO modified) (3), trimethylolpropane tri(meth)acrylate propionoxide modified (PO modified) (6), pentaerythritol tri(meth)acrylate, glycerin tri(meth)acrylate, ethylene oxide modified (EO modified) of glycerin tri(meth)acrylate (3), ethylene oxide modified (EO modified) of glycerin tri(meth)acrylate (6), ethylene oxide modified (EO modified) of glycerin tri(meth)acrylate (9), ethylene oxide modified (EO modified) of glycerin tri(meth)acrylate (20), propionoxide modified (PO modified) of glycerin tri(meth)acrylate (3),Examples of such compounds include propionoxide-modified (PO-modified) glycerin tri(meth)acrylate (5.5), propionoxide-modified (PO-modified) glycerin tri(meth)acrylate (6), propionoxide-modified (PO-modified) glycerin tri(meth)acrylate (9), dimethylol tricyclodecane diacrylate, and (meth)acrylates having different numbers of modifications, different types of modifications, and different structures.

[0059] The active energy ray-curable ink composition according to the present embodiment preferably contains a monofunctional polymerizable compound and a difunctional or higher polyfunctional polymerizable compound (polyfunctional monomer) as a polymerizable compound other than the polymerizable compound represented by general formula (1). When the ink composition contains a monofunctional polymerizable compound and a polyfunctional polymerizable compound, the content of the polyfunctional polymerizable compound is preferably 50% by mass or less, more preferably 35% by mass or less, and even more preferably 25% by mass or less of the total amount of the ink composition.

[0060] Furthermore, when a polyfunctional polymerizable compound (polyfunctional monomer) having 4 or more functionalities is contained, the content is preferably 25% by mass or less in the total amount of the ink composition, more preferably 18% by mass or less in the total amount of the ink composition, even more preferably 15% by mass or less, and even more preferably 10% by mass or less. If the content of the polyfunctional polymerizable compound (polyfunctional monomer) having 4 or more functionalities is too high, curing shrinkage, in which the volume shrinks due to curing, may occur. If curing shrinkage occurs, the ink coating film (cured film) may become relatively more likely to peel off from the substrate, wrinkles or unevenness may occur on the surface of the ink coating film, or cracks or warping of the coating film may occur relatively easily. By having the content of the polyfunctional polymerizable compound (polyfunctional monomer) having 4 or more functionalities within the above range, the printing quality can be improved, and the peeling of the cured film caused by curing shrinkage can be more effectively suppressed, so that it is possible to form a cured film having higher adhesion to the substrate.

[0061] In addition, when the ink composition contains a binder resin having a weight average molecular weight of 10,000 or more, the total content of the binder resin and the polyfunctional polymerizable compound having 4 or more functionalities is preferably 30% by mass or less in the total amount of the ink composition, more preferably 27% by mass or less in the total amount of the ink composition, and even more preferably 25% by mass or less in the total amount of the ink composition. By containing a polyfunctional polymerizable compound having high reactivity and improving crosslink density, and a polymer resin component that improves printing quality and coating resistance in the ink composition, it is possible to achieve a good balance between curability, printing quality, and coating properties, and also to achieve good inkjet ejection properties. By containing the binder resin and the polyfunctional polymerizable compound having 4 or more functionalities in the above range, the effect is further improved.

[0062] In addition, it is preferable to contain a polymerizable oligomer as another polymerizable compound different from the polymerizable compound represented by general formula (1). A polymerizable oligomer generally means a polymer in which a relatively small number of monomers are bonded, and an example of the polymerizable oligomer is a compound in which several to several tens of structural unit molecules are polymerized and the weight average molecular weight is less than 10,000. By containing a predetermined amount of polymerizable oligomer, it is possible to adjust the curability and viscosity of the ink composition. Furthermore, the polymerizable compound represented by general formula (1) has high solubility in the polymerizable oligomer, and the active energy ray curable ink composition according to the present embodiment containing the polymerizable compound represented by general formula (1) can dissolve the polymerizable oligomer and further increase the solubility in other additives, making it possible to expand the ink design range as desired by the designer.

[0063] Examples of polymerizable oligomers include urethane acrylate, epoxy acrylate, polyester acrylate, polymeric acrylate (acrylic acrylate), and the like, and these can be obtained from Rahn AG, Sartomer, Daicel Corporation, Taisei Fine Co., Ltd., Mitsubishi Chemical Corporation, Daiichi Kogyo Seiyaku Co., Ltd., Kyoeisha Chemical Co., Ltd., Shin-Nakamura Chemical Co., Ltd., and the like.

[0064] When the polymerizable oligomer is contained, the content of the polymerizable oligomer is preferably 1.0% by mass or more in the total amount of the ink composition, more preferably 1.3% by mass or more, and even more preferably 1.5% by mass or more. The content of the polymerizable oligomer is preferably 20.0% by mass or less in the total amount of the ink composition, more preferably 17.0% by mass or less, and even more preferably 15.0% by mass or less. The content of the polymerizable oligomer is preferably 1.0% by mass or more and 20.0% by mass or less in the total amount of the ink composition, more preferably 1.3% by mass or more and 17.0% by mass or less, and even more preferably 1.5% by mass or more and 15.0% by mass or less.

[0065] These polymerizable compounds may be solid or liquid at room temperature. Among these, at least one of the polymerizable compounds contained in the ink composition according to the present embodiment is preferably liquid at room temperature. When the polymerizable compound is liquid at room temperature, this liquid polymerizable compound can serve as a solvent (dispersion medium) that dissolves or disperses each component contained in the ink composition.

[0066] The content of the polymerizable compound is not particularly limited, but is preferably 40% by mass or more in the total amount of the ink composition, more preferably 50% by mass or more, and even more preferably 60% by mass or more. When the content of the polymerizable compound is 40% by mass or more in the total amount of the ink composition, the curability of the cured film of the glittering layer formed when irradiated with active energy rays can be improved. The content of the polymerizable compound is preferably 90% by mass or less in the total amount of the ink composition, more preferably 87% by mass or less, and even more preferably 85% by mass or less. When the content of the polymerizable compound is 90% by mass or less in the total amount of the ink composition, the content of the coloring material and the like can be relatively increased, so that the ink composition and the resulting printed matter can be given the desired characteristics. The content of the polymerizable compound is preferably 40% by mass or more and 90% by mass or less in the total amount of the ink composition, more preferably 50% by mass or more and 87% by mass or less, and even more preferably 60% by mass or more and 85% by mass or less.

[0067] [Polymerization initiator] The active energy ray curable ink composition according to this embodiment may contain a polymerization initiator as necessary. The polymerization initiator promotes the polymerization reaction of the polymerizable compound in the ink composition by irradiation with active energy rays. Note that the polymerization initiator is not necessarily essential in the ink composition according to this embodiment. For example, when an electron beam is used as the active energy ray, a polymerization initiator may not be used.

[0068] Specific examples of the polymerization initiator include bisacylphosphine oxides such as bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, and bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, acylphosphine oxide polymerization initiators such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino- Examples of the polymerization initiator include aminoacetophenone-based polymerization initiators such as 1-(4-morpholinophenyl)-butan-1-one and 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, and thioxanthone-based polymerization initiators such as 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-isopropylthioxanthone.

[0069] Among these, diphenyl-2,4,6-trimethylbenzoylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, and 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one can more effectively promote the polymerization reaction of polymerizable compounds, but are candidates for inclusion as substances of high concern in Annex XIV of the REACH Regulation enacted by the European Union. For this reason, it is preferable to contain a polymerization initiator other than these polymerization initiators. Moreover, if the active energy ray curable ink composition according to the present embodiment contains a predetermined amount of the polymerizable compound represented by general formula (1), it is possible to suppress the decrease in the curability of the ink composition even if it contains a polymerization initiator other than these polymerization initiators.

[0070] Polymerization initiators that are not candidates for inclusion as substances of very high concern in Annex XIV of the REACH regulation enacted by the European Union include polymerization initiators containing phosphine oxide derivatives with two or more alkylbenzene structures in the molecule, polymerization initiators containing alkoxyphosphine oxide derivatives, and fluorenyl amino ketone polymerization initiators. Examples include Omnirad 819 (manufactured by IGM Resins BV), A-TPO-N (manufactured by Gyroid Materials), SpeedCure TPO-L (manufactured by Sartomer), SpeedCure XKm (manufactured by Sartomer), NPI-20400 (manufactured by TRONLY), SPEEDCURE BMS (manufactured by Sartomer), and mnirad ITX (manufactured by IGM Resins).

[0071] As a polymerization initiator that is not a candidate for listing as a substance of very high concern, for example, one having the following structure can be preferably used.

[0072] [ka]

[0073] [ka] In formula (3), R 4 is an alkyl group having 1 to 10 carbon atoms which may be branched, and R 5 is an alkyl group having 1 to 10 carbon atoms which may be branched.

[0074] [ka] In formula (4), R 6 is an alkyl group having 1 to 10 carbon atoms which may be branched.

[0075] [ka] In formula (5), R 7 is an alkyl group having 1 to 10 carbon atoms which may be branched.

[0076] [ka] In formula (6), R 8 is an alkyl group having 1 to 10 carbon atoms which may be branched, and R 9 is an alkyl group having 1 to 10 carbon atoms which may be branched.

[0077] [ka] In formula (7), R 10 is an alkyl group having 1 to 10 carbon atoms which may be branched.

[0078] [ka] In formula (8), R 11 is an alkyl group having 1 to 10 carbon atoms which may be branched, and R 12 is an alkyl group having 1 to 10 carbon atoms which may be branched.

[0079] When the active energy ray curable ink composition according to the present embodiment contains a polymerization initiator, the content of the polymerization initiator is not particularly limited, but is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, and even more preferably 2.0% by mass or more in the total amount of the ink composition. The content of the polymerization initiator is preferably 15.0% by mass or less, more preferably 12.0% by mass or less, and even more preferably 10.0% by mass or less in the total amount of the ink composition. The content of the polymerization initiator is preferably 1.0% by mass or more and 15.0% by mass or less, more preferably 1.5% by mass or more and 12.0% by mass or less, and even more preferably 2.0% by mass or more and 10.0% by mass or less in the total amount of the ink composition.

[0080] [Polymerization inhibitor] The ink composition according to the present embodiment may contain a polymerization inhibitor as necessary. The polymerization inhibitor is not particularly limited, and examples of the polymerization inhibitor that can be used include diphenylpicrylhydrazide, tri-p-nitrophenylmethyl, p-benzoquinone, p-tert-butylcatechol, picric acid, copper chloride, methylhydroquinone, methoquinone, tert-butylhydroquinone, phenothiazines, and nitrosamines.

[0081] [Colorant] The active energy ray curable ink composition according to the present embodiment may contain a coloring material as necessary. When the active energy ray curable ink composition according to the present embodiment contains a coloring material, the coloring material is not particularly limited and may be a dye-based material or a pigment-based material, but it is preferable to use a pigment (pigment-based coloring material) from the viewpoint of good resistance such as water resistance and light resistance of the recorded matter. In the active energy ray curable ink composition according to the present embodiment, the pigment that can be used is not particularly limited, and examples thereof include organic pigments and inorganic pigments used in conventional ink compositions. These may be used alone or in combination of two or more types. The ink composition according to the present embodiment may not contain a coloring material. In addition, a pigment or a dye may be included in the resin.

[0082] When a pigment is used in the active energy ray-curable ink composition according to this embodiment, the dispersion stability of the pigment can be improved by using a dispersant, a dispersion aid (pigment derivative), and a surfactant, which will be described later.

[0083] Specific examples of organic pigments include insoluble azo pigments, soluble azo pigments, derivatives from dyes, phthalocyanine organic pigments, quinacridone organic pigments, perylene organic pigments, perinone organic pigments, azomethine organic pigments, anthraquinone organic pigments (anthrone organic pigments), xanthene organic pigments, diketopyrrolopyrrole organic pigments, dioxazine organic pigments, nickel azo pigments, isoindolinone organic pigments, pyranthrone organic pigments, thioindigo organic pigments, condensed azo organic pigments, benzimidazolone organic pigments, quinophthalone organic pigments, isoindoline organic pigments, quinacridone solid solution pigments, organic solid solution pigments such as perylene solid solution pigments, and other pigments such as lake pigments and carbon black.

[0084] Examples of organic pigments by Color Index (CI) number are: CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, 213, 214; CI Pigment Red 5, 7, 9, 12, 48, 49, 52, 53, 57:1, 97, 112, 122, 123, 146, 149, 150, 168, 177, 180, 184 , 192, 202, 206, 208, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254, 255, 269, 291, CI Pigment Orange 16, 36, 43, 51, 55, 59, 61, 64, 71, 73, CI Pigment Violet 19, 23, 29, 30, 37, 40, 50, CI Pigment Blue 15, 15:1, 15:3, 15:4, 15:6, 16, 22, 60, 64, CI Pigment Green 7, 36, 58, 59, 62, 63, CI Pigment Brown 23, 25, 26, CI Pigment Black 7, etc.

[0085] Specific examples of dyes that can be used in the actinic energy ray-curable ink composition according to this embodiment include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes such as indigoid, fulgide dyes, nickel complex dyes, and azulene dyes.

[0086] Specific examples of inorganic pigments that can be used in the active energy ray-curable ink composition according to this embodiment include titanium oxide, barium sulfate, calcium carbonate, zinc oxide, barium carbonate, silica, talc, clay, synthetic mica, alumina, zinc oxide, lead sulfate, yellow lead, zinc yellow, red iron oxide (red iron (III)), ultramarine, Prussian blue, chromium oxide green, cobalt green, amber, titanium black, aluminum, titanium, indium, nickel, chromium, gold, silver, copper, synthetic iron black, iron oxide, mica, fish scale foil, bismuth oxychloride, inorganic solid solution pigments, etc. In addition to the above pigments, materials having optical properties or functionality other than those for decorative purposes, such as conductive pigments, insulating pigments, pigments that absorb specific wavelengths, and pigments that emit or reflect specific wavelengths, can also be mentioned.

[0087] In the active energy ray curable ink composition according to the present embodiment, the average particle diameter of the pigment that can be contained is not particularly limited as long as it can produce the desired color. Although it varies depending on the type of pigment used, from the viewpoint of obtaining good dispersibility and dispersion stability of the pigment and sufficient coloring power, the average particle diameter is preferably in the range of 5 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more. When the average particle diameter is equal to or more than the above lower limit, the light resistance of the ink composition can be improved. From the viewpoint of dispersion stability in the ink composition and inkjet dischargeability, the average particle diameter is preferably in the range of 1000 nm or less, more preferably 800 nm or less, even more preferably 500 nm or less, and even more preferably 350 nm. The average particle diameter of the pigment is preferably in the range of 5 nm or more and 1000 nm or less, more preferably 20 nm or more and 800 nm or less, and even more preferably 30 nm or more and 500 nm or less.

[0088] In this embodiment, the volume-average particle diameter of the pigment is the volume-based cumulative 50% particle diameter (D50) measured under conditions of 25°C using a particle diameter distribution measuring device (such as a particle size analyzer NANOTRACWAVE manufactured by Microtrackbell Co., Ltd., "FPIA-3000S" manufactured by Sysmex Corporation, or "FPAR-1000" manufactured by Otsuka Electronics Co., Ltd.). In this specification, "volume-based cumulative 50% particle diameter (D50)" refers to a particle diameter at which the cumulative volume calculated from the small diameter side is 50%. "Volume-based cumulative 50% particle diameter (D50)" may also be referred to as "volume-average particle diameter", "average particle diameter", or "median diameter".

[0089] In the active energy ray curable ink composition according to the present embodiment, the content of the pigment is not particularly limited as long as the desired image can be formed, and is appropriately adjusted. Specifically, although it varies depending on the type of pigment, it is preferably in the range of 0.05% by mass or more in the total amount of the ink composition, more preferably in the range of 0.08% by mass or more, and even more preferably in the range of 0.1% by mass or more. It is preferably in the range of 20% by mass or less in the total amount of the ink composition, more preferably in the range of 15% by mass or less, and even more preferably in the range of 10% by mass or less. The content of the pigment is preferably in the range of 0.05% by mass or more and 20% by mass or less in the total amount of the ink composition, more preferably in the range of 0.08% by mass or more and 15% by mass or less, and even more preferably in the range of 0.1% by mass or more and 10% by mass or less. By having the content of the pigment in the range of 0.05% by mass or more or in the range of 20% by mass or less, it is possible to obtain an excellent balance between the dispersion stability and the coloring power of the pigment.

[0090] In addition, the active energy ray curable ink composition according to the present embodiment is not particularly limited in the color to be recorded (printed), and may be selected and used in combination according to the purpose. The colors may be used in inks of various colors such as yellow, magenta, cyan, black, red, orange, violet, blue, and green, as well as light magenta, light cyan, light black, white, clear, and glitter inks. In this case, coloring materials of the same color may be selected in an ink set including the active energy ray curable ink composition according to the present embodiment.

[0091] [Dispersant] A dispersant may be used as necessary in the active energy ray-curable ink composition according to this embodiment. As the dispersant, any dispersant used in ink compositions may be used. As the dispersant, a polymer dispersant may be used. Such a dispersant has a main chain made of a polyester, polyacrylic, polyurethane, polyamine, polycaprolactone, or the like, and has a polar group such as an amino group, a carboxyl group, a sulfone group, or a hydroxyl group as a side chain. Examples of polyacrylic dispersants include Disperbyk-2000, 2001, 2008, 2009, 2010, 2020, 2020N, ​​2022, 2025, 2050, 2070, 2095, 2150, 2151, 2155, 2163, 2164, BYKJET-9130, 9131, 9132, 9133, 9151, 9152 (manufactured by BYK), EfkaPX4310, PX4320, PX4330, PA4401, 4402, PA4403, 4570, 7411, 7477, PX4700, PX4701, PX4703 (manufactured by BASF), and TREPLUS. D-1200, D-1410, D-1420, MD-1000 (manufactured by Otsuka Chemical Co., Ltd.), Florene DOPA-15BHFS, 17HF, 22, G-700, 900, NC-500, GW-1500 (manufactured by Kyoeisha Chemical Co., Ltd.), etc. are used. Examples of polycaprolactone-based dispersants include AJISPER PB821, PB822, and PB881 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Hinoact KF-1000, T-6000, T-7000, T-8000, T-8000E, and T-9050 (manufactured by Kawaken Fine Chemical Co., Ltd.), Solsperse 20000, 24000, 32000, 32500, 32550, 32600, 33000, 33500, 34000, 35200, 36000, 37500, 39000, 71000, 76400, 76500, 86000, 88000, J180, and J200 (manufactured by Lubrizol Corporation), and TEGO Dispers 652, 655, 685, 688, 690 (manufactured by Evonik), etc. are used.Preferred dispersants include PB881, BYKJET-9130, 9131, 9132, 9133, 9151, 9152, Efka PX4310, PX4320, PX4330, PX4700, PX4701, PX4703, Solsperse 20000, 24000, 32000, 33000, 33500, 34000, 35200, 39000, 71000, 76500, 86000, 88000, J180, J200, TEGO Dispers 655, 685, 688, and 690. These may be used alone or in mixtures thereof.

[0092] The content of the dispersant is not particularly limited, but is preferably adjusted according to the content of the colorant contained in the ink composition. In particular, in the active energy ray curable ink composition according to the present embodiment containing the polymerizable compound represented by the general formula (1), it is preferable to adjust the content of the dispersant so that the content of the colorant is greater than the content of the dispersant (i.e., the content of the dispersant is less than the content of the colorant). This makes it possible to effectively disperse the colorant in the ink composition, thereby improving the storage stability and ejection stability of the ink composition.

[0093] The lower limit of the content of the dispersant is not particularly limited. 1 , R 2 , R 3 Depending on the content of compound (1) and other components, R is added as necessary. 2 , R 3 When the alkyl group has 2 to 4 carbon atoms, the dispersibility may be particularly good, and the amount of dispersant used may be reduced.

[0094] When the colorant is an organic colorant, the upper limit of the content of the dispersant is preferably 80 parts by mass or less, more preferably 75 parts by mass or less, even more preferably 50 parts by mass or less, and even more preferably 35 parts by mass or less, relative to 100 parts by mass of the colorant.

[0095] When the colorant is an inorganic colorant, the upper limit of the content of the dispersant is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, per 100 parts by mass of the colorant.

[0096] [Dispersion aid] The active energy ray-curable ink composition according to this embodiment may contain a dispersion aid as necessary. The dispersion aid is adsorbed to the surface of the colorant (pigment), and the functional group enhances the affinity with the polymerizable compound and dispersant in the ink composition, thereby improving the dispersion stability. As the dispersion aid, a known pigment derivative having a functional group such as an acidic group, a basic group, or a neutral group in the organic pigment residue can be used.

[0097] [Surfactants] The ink composition according to this embodiment may contain a surfactant as necessary. The surfactant is not particularly limited, but specific examples thereof include dimethylpolysiloxane-containing surfactants manufactured by BYK, such as "BYK-306", "BYK-307", "BYK-331", "BYK-333", "BYK-354", "BYK-361N", "BYK-371", "BYK-377", "BYK-378", "BYK-3455", "BYK-UV3500", "BYK-UV3505", "BYK-UV3510", "BYK-UV3535", and "BYK-UV3570"; and Evonik, such as "TEGO Flow425", "TEGO Glide100", "TEGO Glide110", "TEGO Glide130", "TEGO Glide432", "TEGO Glide435", "TEGO Glide440", "TEGO Glide450", "TEGO GlideZG400", "TEGO Twin4000", "TEGO Twin4200", "TEGO Wet270", and "TEGO Examples of such polymers include "Polyflow KL-401", "Polyflow KL-402", "Polyflow KL-403", and "Polyflow KL-404" manufactured by Kyoeisha Chemical Co., Ltd.; acrylic polymers include "Polyflow No. 75", "Polyflow No. 77", "Polyflow No. 90", "Polyflow No. 95", and "Polyflow No. 99C" manufactured by Kyoeisha Chemical Co., Ltd.; and "TEGO Wet500" manufactured by Evonik Degussa Japan Ltd.

[0098] The content of the surfactant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, based on the total amount of the ink composition. The content of the surfactant is preferably 5.0% by mass or less, more preferably 4.5% by mass or less, and even more preferably 4.0% by mass or less, based on the total amount of the ink composition. By setting the content to 0.1% by mass or more or 5.0% by mass or less, the ink composition has favorable wettability with respect to a thermoplastic resin substrate, etc., and when recording (forming an image) on the substrate, the active energy ray curable ink composition can be wetted and spread without causing repelling, so that a particularly preferable ink composition can be obtained. The content of the surfactant is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.2% by mass or more and 4.5% by mass or less, and even more preferably 0.3% by mass or more and 4.0% by mass or less, based on the total amount of the ink composition.

[0099] [Binder resin] The active energy ray curable ink composition according to the present embodiment may contain a binder resin as necessary. The binder resin referred to here means a non-polymerizable resin, which is different from additives such as polymerizable resins, polymerizable oligomers, surfactants, and dispersants for dispersing coloring materials. The resin is not particularly limited, but examples thereof include acrylic resins, polystyrene resins, polyester resins, polyethylene terephthalate resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride / vinyl acetate copolymer resins, polyethylene resins, polyurethane resins, rosin-modified resins, phenol resins, xylene resins, terpene resins, polyamide resins, vinyl toluene-α-methylstyrene copolymers, ethylene-vinyl acetate copolymers, cellulose resins, silicone (silicon) resins, acrylamide resins, epoxy resins, diallyl phthalate resins, allyl resins, or copolymer resins or mixtures thereof. Among these, it is preferable to use one or more of vinyl chloride-vinyl acetate copolymer resin, polyethylene terephthalate resin, diallyl phthalate resin, acrylic resin, allyl resin, xylene resin, and cellulose resin, and it is more preferable to use at least one selected from the group consisting of vinyl chloride-vinyl acetate copolymer resin, diallyl phthalate resin, xylene resin, and acrylic resin. The weight-average molecular weight of the binder resin is preferably 10,000 or more, more preferably 15,000 or more. The weight-average molecular weight of the binder resin is preferably 500,000 or less, more preferably 300,000 or less. By using the weight-average molecular weight of the binder resin within this range, the storage stability, ejection property, and coating film properties of the ink composition can be improved.

[0100] By containing a binder resin together with the polymerizable compound, it becomes possible to cure the ink composition in a state where the density inside the coating film is increased, and it becomes possible to improve the abrasion resistance and chemical resistance of the coating film formed. On the other hand, when a binder resin is contained together with the polymerizable compound, a part of the contained components such as the binder resin may precipitate during storage of the ink composition, which may relatively reduce the storage stability and ejection stability, and further the formed coating film may become non-uniform and further the color development may be reduced. Here, since the polymerizable compound represented by the general formula (1) has high solubility in the contained components, the storage stability and ejection stability are unlikely to decrease. For this reason, by using an ink composition containing a binder resin together with the polymerizable compound represented by the general formula (1), it becomes possible to enjoy only the benefit of improving the abrasion resistance and chemical resistance of the coating film formed while avoiding the disadvantages of containing the binder resin. Furthermore, the polymerizable compound represented by the general formula (1) has a low viscosity, and even if a specific component such as a binder resin is contained, the viscosity of the ink composition does not become too high, and it is possible to suppress the decrease in storage stability and ejection stability.

[0101] When the active energy ray curable ink composition according to the present embodiment contains a binder resin, the content of the binder resin is not particularly limited, but is preferably 0.05% by mass or more, more preferably 0.08% by mass or more, even more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more of the total amount of the ink composition. The content of the binder resin is preferably 20.0% by mass or less, more preferably 15.0% by mass or less, even more preferably 10.0% by mass or less, and even more preferably 5.0% by mass or less of the total amount of the ink composition. The content of the binder resin is preferably 0.05% by mass or more and 20.0% by mass or less, more preferably 0.08% by mass or more and 15.0% by mass or less, and even more preferably 0.1% by mass or more and 10.0% by mass or less of the total amount of the ink composition.

[0102] [Other additives] The ink composition according to this embodiment may contain various other additives, such as an organic solvent, a plasticizer, a light stabilizer, a wax, an ultraviolet absorber, an antioxidant, an alignment agent, an antibacterial agent, and an antiviral agent.

[0103] In addition, the ink composition according to the present embodiment may contain a volatile organic solvent, but if the polymerizable compound contained therein is liquid at room temperature, the polymerizable compound becomes a solvent (dispersion medium) that dissolves or disperses each of the contained components, so the ink composition may not contain a volatile organic solvent. Among these, if the polymerizable compound contained therein is liquid at room temperature, the content of the volatile organic solvent is preferably 20.0 mass % or less of the total amount of the ink composition, more preferably 10.0 mass % or less, even more preferably 5.0 mass % or less, and even more preferably 1.0 mass % or less. When the polymerizable compound contains a liquid compound at room temperature and the content of the volatile organic solvent is 20.0 mass % or less of the total amount of the ink composition, it is possible to suppress the precipitation of the contained components due to the volatilization of the ink composition in the inkjet nozzle, and therefore it is possible to further improve the ejection property of the inkjet.

[0104] (Viscosity and surface tension of ink composition) From the viewpoint of inkjet ejection properties and ejection stability, the viscosity of the ink composition according to the present embodiment at the ejection temperature (for example, 40°C) is preferably 30 mPa·s or less, more preferably 25 mPa·s or less, and even more preferably 22 mPa·s or less. The viscosity of the ink composition according to the present embodiment at the ejection temperature (for example, 40°C) is preferably 3 mPa·s or more, more preferably 5 mPa·s or more, and even more preferably 8 mPa·s or more, but it is preferable to adjust it appropriately according to the inkjet head used. The viscosity can be measured with a vibration viscometer, a rheometer, a falling ball viscometer, or the like.

[0105] Moreover, from the viewpoints of inkjet ejection properties, ejection stability, and leveling properties on a substrate, the surface tension of the ink composition according to this embodiment is preferably 20 mN / m or more, more preferably 23 mN / m or more, and even more preferably 25 mN / m or more at 25° C. Moreover, the surface tension of the ink composition according to this embodiment is preferably 40 mN / m or less, more preferably 37 mN / m or less, and even more preferably 35 mN / m or less.

[0106] (Method of producing ink composition) The method for producing the actinic energy ray-curable ink composition according to one embodiment of the present invention is not particularly limited, and a conventionally known method can be used. For example, a polymerizable compound, a colorant, and a dispersant, if necessary, are mixed and dispersed using a dispersing machine, and then a polymerization initiator, and if necessary a polymerization inhibitor, a leveling agent, and the like are added and stirred uniformly to obtain a mixture, which is then filtered through a filter to obtain an ink composition.

[0107] 2. Ink set The actinic ray-curable ink composition may be a color ink, a clear ink that does not contain a coloring material, a primer ink, or an overcoat ink. The ink set according to the present embodiment may be an ink set that combines these ink compositions.

[0108] The ink set according to the present embodiment may be any ink set in which at least one ink composition contains a polymerizable compound represented by the general formula (1). For example, in an ink set containing ink composition A and ink composition B, ink composition A may be an ink composition containing a polymerizable compound represented by the general formula (1), and ink composition B may be an ink composition different from the ink composition containing the polymerizable compound represented by the general formula (1). In addition, both ink composition A and ink composition B may be ink compositions containing a polymerizable compound represented by the general formula (1). The same applies to ink sets containing three or more types of ink compositions.

[0109] In addition, the ink set may be a combination of colored ink compositions containing a coloring material, and may be an ink set that combines a plurality of ink compositions selected from, for example, colored ink compositions of yellow, magenta, cyan, black, red, orange, violet, blue, green, intermediate colors or pale colors thereof, a white ink composition containing a white coloring material, or a metallic ink containing a glittering coloring material.

[0110] 3. Recording method The recording method according to this embodiment is a recording method in which an ink composition containing a polymerizable compound represented by general formula (1) is applied onto a substrate by an inkjet method.

[0111] An ink composition containing a polymerizable compound represented by general formula (1) can form a cured film of the ink composition that has good adhesion to various substrates.

[0112] The recording method according to the present embodiment may also include a step of ink-jetting an ink composition containing a polymerizable compound represented by general formula (1) onto the surface of a surface-treated resin substrate.

[0113] The method may further include an irradiation step of irradiating the ink composition applied to the surface of the substrate with active energy rays. This irradiation forms a cured product of the ink composition on the surface of the substrate. Examples of active energy rays include electromagnetic waves such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, visible light, infrared rays, X-rays, and gamma rays, as well as active energy rays such as electron beams, proton beams, and neutron beams. Among these, active energy rays having a peak wavelength of 365 nm or more and 395 nm or less are preferred.

[0114] The light source for irradiating the active energy rays is not particularly limited, and examples thereof include a high-pressure mercury lamp, a metal halide lamp, a low-pressure mercury lamp, an ultra-high-pressure mercury lamp, an ultraviolet laser, sunlight, an LED lamp, etc. From the viewpoint of energy saving and high degree of freedom in designing the printing device, it is more preferable to use an LED lamp as the light source.

[0115] In order to obtain a surface-treated resin substrate, the method may include a pretreatment step of previously subjecting the surface of the substrate to a surface treatment to obtain a surface-treated substrate.

[0116] Examples of the surface treatment method include corona treatment, flame treatment, plasma treatment, flame treatment, ultraviolet irradiation treatment, chromic acid treatment, silane coupling treatment, etc. Two or more surface treatments may be combined.

[0117] The substrate to be pretreated may be either a non-absorbent substrate or an absorbent substrate, as described below.

[0118] The inkjet ejection method for the ink composition containing the polymerizable compound represented by formula (1) may be any of a piezoelectric method, an electrostatic method, etc. The inkjet method may be a serial head method or a line head method, and is not particularly limited.

[0119] Furthermore, the ink composition containing the polymerizable compound represented by formula (1) may be applied onto a substrate by a method other than inkjet printing, such as a spray or a dispenser.

[0120] ≪4. Manufacturing method of printed matter≫ The above-mentioned recording method can also be defined as a method for producing a printed matter by applying an ink composition containing the polymerizable compound represented by general formula (1) onto a substrate by an inkjet method. In addition, a printed matter can also be produced by applying the ink composition onto a substrate by a method other than the inkjet method, for example, a spray or a dispenser.

[0121] ≪5.Printed materials≫ A printed matter obtained by using the ink composition according to the above embodiment includes a substrate (recording medium) and a layer of a cured material formed on the surface of the substrate (recording medium). The layer of the cured material contains a cured product of the polymerizable compound contained in the ink composition according to the above embodiment.

[0122] Here, since the polymerizable compound contained in the ink composition according to the above embodiment contains a polymerizable compound represented by general formula (1), it is possible to form a cured film with high adhesion to various substrates such as substrates of flexible polyvinyl chloride resins and acrylic resins with high hardness. Furthermore, even when the ink composition does not contain a polymerization initiator or contains a polymerization initiator that is not a substance of high concern listed in Annex XIV of the REACH Regulation as a polymerization initiator, it is possible to effectively suppress a decrease in the curability of the ink composition.

[0123] [Substrate (recording medium)] The substrate (recording medium) included in the recorded matter of this embodiment is not particularly limited, and may be a non-absorbent substrate such as a resin substrate, a metal plate, or glass, an absorbent substrate such as paper or cloth, or a substrate with a surface coating such as a substrate having a receiving layer, and various substrates can be used.

[0124] Examples of non-absorbent substrates include resin substrates such as polyester resins (polyethylene terephthalate, polyethylene naphthalate), polypropylene synthetic paper, polyolefin resins (polypropylene resins, polyethylene resins, etc.), acrylic resins, polystyrene resins, polycarbonate resins, ABS resins, vinyl chloride resins, polyimide resins, metals, metal foil coated paper, glass, synthetic rubber, natural rubber, etc. Among these, resin substrates containing at least one selected from the group consisting of polypropylene resins, polycarbonate resins, polystyrene resins, polyethylene resins, ABS resins, vinyl chloride resins, polyethylene terephthalate resins, and acrylic resins are preferred.

[0125] In particular, since the ink composition containing the polymerizable compound represented by general formula (1) can form a cured film having high adhesion even to polyvinyl chloride resin or acrylic resin substrates, it is particularly preferable that the substrate (recording medium) is a polyvinyl chloride resin or acrylic resin substrate.

[0126] Examples of absorbent substrates include woody paper, medium-quality paper, fine paper, synthetic paper, cotton, chemical fiber fabrics, silk, hemp, cloth, nonwoven fabrics, and leather.

[0127] Examples of substrates having a coated surface include coated paper, art paper, cast paper, lightly coated paper, and lightly coated paper.

[0128] [Cured film of ink composition] The cured film of the ink composition is formed by polymerization of the polymerizable compound contained in the ink composition. For example, when the ink composition contains a coloring material, it becomes a decorative layer that forms a desired image or a base layer thereof. In this specification, the shape of the "cured film" is not limited to, for example, a flat plate or a layer, and may have unevenness, may have holes formed in a part, or may have a cured film formed on a part of the surface. In addition, for convenience, the cured film of the ink composition that is absorbed into an absorbent substrate and is substantially in a state like a part of the substrate is also referred to as the cured film of the ink composition.

[0129] When an ink composition containing a polymerizable compound represented by general formula (1) is used as an overcoat ink, it becomes an overcoat layer formed on the surface of a recorded material. In this case, the ink composition forming the recording layer of the recorded material may be a polymerizable compound ink composition represented by general formula (1), or may be an ink composition different from the polymerizable compound ink composition represented by general formula (1).

[0130] The thickness of the cured product of the ink composition containing the polymerizable compound represented by the general formula (1) (e.g., a recording layer or an overcoat layer) is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. The thickness of the cured product of the ink composition (e.g., a recording layer or an overcoat layer) is preferably 100 μm or less, more preferably 90 μm or less, and even more preferably 80 μm or less. The thickness of the cured product of the ink composition is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 90 μm or less, and even more preferably 10 μm or more and 80 μm or less. The cured product of the ink composition can be given a desired function. The thickness of the cured product is the average value of thicknesses measured at multiple arbitrary points on the surface of the cured product.

[0131] 6. Inkjet recording device The ink jet recording apparatus according to this embodiment is an ink jet recording apparatus equipped with a storage mechanism filled with an ink composition containing a polymerizable compound represented by general formula (1).

[0132] The inkjet recording apparatus according to the present embodiment may be an inkjet recording apparatus of a multi-pass type (also called a serial head type) in which an inkjet head reciprocates to eject an ink composition, or an inkjet recording apparatus of a single-pass type (also called a line head type) in which an inkjet head does not move and ejects an ink composition onto a recording medium (substrate).

[0133] The storage mechanism mounted on the inkjet recording apparatus according to the present embodiment is not particularly limited, and examples thereof include containers such as ink bottles, pouches, bag-in-boxes, and drums. These containers may also be housed in cartridges or the like. The material of the storage container is not particularly limited, and may be a conventionally known resin, or may be a material that contains a metal material in part (for example, an aluminum pouch with an aluminum vapor deposition layer).

[0134] The ejection method in each ejection section may be any of a piezoelectric method, a thermal method, an electrostatic method, and the like.

[0135] The inkjet recording apparatus according to the present embodiment may include a light source that irradiates active energy rays. The light source that irradiates active energy rays is not particularly limited, and examples thereof include a high-pressure mercury lamp, a metal halide lamp, a low-pressure mercury lamp, an ultra-high-pressure mercury lamp, an ultraviolet laser, sunlight, and an LED lamp. It is more preferable to use an LED lamp as the light source in view of energy saving and high flexibility in designing the printing apparatus. EXAMPLES

[0136] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these descriptions in any way.

[0137] 1. Preparation of ink composition Ink compositions of experimental examples and comparative examples were produced. Specifically, the ink compositions of the examples and comparative examples were prepared so that the polymerizable monomer, polymerization initiator, polymerization inhibitor, and color material (pigment mill base) were mixed in the ratios shown in the table below. The units in the table are mass %.

[0138] 2. Evaluation of ink composition (Storage stability) The storage stability of the ink compositions of the examples and comparative examples was evaluated. Specifically, the ink compositions of the examples and comparative examples were sealed in light-shielding glass bottles and stored at a temperature of 60° C. for 7 days, and the ink compositions after storage were visually inspected for the occurrence of precipitates or aggregates. Furthermore, the viscosity of the ink compositions before and after storage was measured, and the viscosity change rate was evaluated. [Evaluation Criteria] A: No precipitates or aggregates were generated, and the viscosity change rate was less than 10%. B: No precipitates or aggregates were generated, and the viscosity change rate was 10% or more and less than 20%. C: The occurrence of precipitates or aggregates was confirmed, or the viscosity change rate was 10% or more. A and B are within the usable range.

[0139] (Dischargeability) The ink compositions of the examples and comparative examples were evaluated for ejection properties (inkjet ejection properties). Specifically, the ink compositions of the examples and comparative examples were ejected from an inkjet head for 10 minutes using a droplet observation device JetXpert manufactured by ImageXpert, and the occurrence rates of ejection defects such as non-ejection, bending, and scattering of the inkjet head were evaluated. [Evaluation Criteria] AA: The rate of ejection defects is less than 1%. A: The rate of defective discharge is between 1% and 3%. B: The rate of ejection defects is 3% or more and less than 10%. C: The rate of ejection defects is 10% or more. AA, A, and B are within the usable range.

[0140] (curable) The ink compositions of the examples and comparative examples were evaluated for curability. Specifically, the ink compositions of the examples and comparative examples were ejected onto the surface of a PET film (Cosmoshine A4300, Toyobo Co., Ltd.) using an inkjet recording device, Fujifilm Corporation's "Material Printer DMP-2850," and the ink compositions were then exposed to an LED lamp with a wavelength of 385 nm and a peak illuminance of 250 mW / cm. 2 , cumulative light intensity 650mJ / cm 2 The ink composition was cured on the surface of the PET film by irradiation with active energy rays of 1000 rpm, and the curability of the cured product was evaluated according to the following evaluation criteria. [Evaluation Criteria] AA: No ink remained even when rubbed with a cotton swab. A: Even when I rubbed it with a cotton swab, almost no ink came off. B: Although it was slightly sticky, no ink adhered to it even when rubbed with a cotton swab. C: Ink came off when rubbed with a cotton swab. AA, A, and B are within the usable range.

[0141] (Abrasion resistance 1) The ink compositions of the Examples and Comparative Examples were evaluated for abrasion resistance (abrasion resistance on a vinyl chloride film). Specifically, the ink compositions of the Examples and Comparative Examples were ejected onto the surface of a vinyl chloride film (IMAGin JT5829R: manufactured by MACtac) using an inkjet recording device, Fujifilm's Material Printer DMP-2850, and the ink compositions were then exposed to an LED lamp with a wavelength of 385 nm and a peak illuminance of 250 mW / cm. 2 , cumulative light intensity 650mJ / cm 2 The printed surface of the printed matter was rubbed 50 times with a test cloth at a load of 200 g, and evaluated according to the following evaluation criteria. A and B are within the range of practical use. [Evaluation Criteria] AA: The cured film did not peel off, and no ink was attached to the test cloth. A: The cured film hardly peeled off, and almost no ink adhered to the test cloth. B: The cured film peeled off slightly, and a small amount of ink was adhered to the test cloth piece. C: The cured film peeled off and the ink adhered to the test cloth piece. AA, A, and B are within the usable range.

[0142] (Abrasion resistance 2) For the ink compositions of the Examples and Comparative Examples, a test piece prepared in the same manner as in Abrasion Resistance 1 was used, and the printed surface of the printed matter was rubbed five times with a test cloth to which a 50% by mass aqueous ethanol solution had been applied, with a load of 200 g, and evaluated according to the following evaluation criteria. A and B are within the range of practical use. [Evaluation Criteria] AA: The cured film did not peel off, and no ink was attached to the test cloth. A: The cured film hardly peeled off, and almost no ink adhered to the test cloth. B: The cured film peeled off slightly, and a small amount of ink was adhered to the test cloth piece. C: The cured film peeled off and the ink adhered to the test cloth piece. AA, A, and B are within the usable range.

[0143] (Adhesion 1) The ink compositions of the Examples and Comparative Examples were evaluated for adhesion of the cured film on a PET film. Specifically, the ink compositions of the Examples and Comparative Examples were ejected onto the surface of a PET film (Cosmoshine A4360, Toyobo Co., Ltd.) using an inkjet recording device, Fujifilm Corporation's "Material Printer DMP-2850," and the ink was then exposed to a 385 nm LED lamp with a peak illuminance of 250 mW / cm. 2 , cumulative light intensity 650mJ / cm 2 The metal foil was irradiated with active energy rays of 1000 rpm, an adhesive tape (Cellotape (registered trademark) CT-18 manufactured by Nichiban Co., Ltd.) was adhered to the surface, and the metal foil surface was visually inspected for peeling when the tape was peeled off, and evaluated according to the following evaluation criteria. [Evaluation Criteria] AA: No peeling occurred. A: Almost no peeling occurred. B: Peeling was observed, but was generally within the acceptable range. C: The area of ​​the peeled surface was half or more of the surface to which the adhesive tape was attached. AA, A, and B are within the usable range.

[0144] (Adhesion 2) The ink compositions of the Examples and Comparative Examples were evaluated for adhesion of the cured film on an acrylic resin plate. The ink compositions of the Examples and Comparative Examples were ejected onto the surface of an acrylic resin plate (Acrylite L, Mitsubishi Chemical Corporation) using an inkjet recording device, Fujifilm Corporation's "Material Printer DMP-2850," and the ink compositions were illuminated with an LED lamp with a wavelength of 385 nm at a peak illuminance of 250 mW / cm. 2 , cumulative light intensity 650mJ / cm 2 The metal foil was irradiated with active energy rays of 1000 rpm, an adhesive tape (Cellotape (registered trademark) CT-18 manufactured by Nichiban Co., Ltd.) was adhered to the surface, and the metal foil surface was visually inspected for peeling when the tape was peeled off, and evaluated according to the following evaluation criteria. [Evaluation Criteria] AA: No peeling occurred. A: Almost no peeling occurred. B: Peeling was observed, but was generally within the acceptable range. C: The area of ​​the peeled surface was half or more of the surface to which the adhesive tape was attached. AA, A, and B are within the usable range.

[0145] (Substance of very high concern) It was confirmed whether each component contained in the ink compositions of the examples and comparative examples contained substances that were candidates for inclusion as substances of very high concern. Specifically, the ink compositions that did not contain substances that were candidates for inclusion as "substances subject to authorization" (substances of very high concern) listed in Annex XIV of the REACH regulation enacted by the European Union were classified as "A," and the ink compositions that contained substances that were candidates for inclusion as "substances subject to authorization" (substances of very high concern) listed in Annex XIV of the REACH regulation enacted by the European Union were classified as "C."

[0146] [Table 1]

[0147] [Table 2]

[0148] [Table 3]

[0149] [Table 4]

[0150] In the table, the pigment (coloring material) "PR122" is CI Pigment Red 122. In the table, the pigment (coloring material) "PV19" stands for CI Pigment Violet 19. In the table, the pigment (coloring material) "PR254" is CI Pigment Red 254. In the table, the pigment (coloring material) "PR202" is CI Pigment Red 202. In the table, the pigment (colorant) "PB15:4" stands for CI Pigment Blue 15:4. In the table, the pigment (colorant) "PB15:6" stands for CI Pigment Blue 15:6. In the table, the pigment (coloring material) "PY138" stands for CI Pigment Yellow 138. In the table, the pigment (coloring material) "PY150" stands for CI Pigment Yellow 150. In the table, the pigment (coloring material) "PY155" is CI Pigment Yellow 155. In the table, the pigment (colorant) "PG36" stands for CI Pigment Green 36. In the table, the pigment (colorant) "PG58" stands for CI Pigment Green 58. In the table, the pigment (colorant) "PB7" stands for CI Pigment Black 7. In the table, the pigment (colorant) "PW6" stands for CI Pigment White 6. In the table, "D1" for dispersant (dispersant for dispersing colorant) is Solsperse 33000 (manufactured by Lubrizol Corporation). In the table, "D2" for dispersant (dispersant for dispersing colorant) is BYK9151 (manufactured by BYK). In the table, "D3" for dispersant (dispersant for dispersing colorant) is PX4701 (manufactured by Efka). In the table, "DMAA" for the polymerizable compound of formula (1) is N,N-dimethylacrylamide. In the table, "DEAA" in the polymerizable compound of formula (1) is N,N-diethylacrylamide. In the table, "DBAA" for the polymerizable compound of formula (1) is N,N-dibutylacrylamide. In the table, "OAA" for the polymerizable compound of formula (1) is N-octylacrylamide. In the table, "AA" of the polymerizable compound of formula (1) is acrylamide. In the table, "HMAA" for the polymerizable compound of formula (1) is N-(hydroxymethyl)acrylamide. In the table, the monofunctional polymerizable compound "PHEA" stands for phenoxyethyl acrylate. In the table, the monofunctional polymerizable compound "IBXA" is isobornyl acrylate. In the table, "TBCH" for the monofunctional polymerizable compound is tert-butyl acrylate. In the table, "CTFA" for the monofunctional polymerizable compound is cyclic trimethylolpropane formal acrylate. In the table, "NOA" for the monofunctional polymerizable compound is n-octyl acrylate. In the table, the polyfunctional polymerizable compound "PO(3)-TMPTA" is PO-modified trimethylolpropane triacrylate. In the table, the polyfunctional polymerizable compound "16HDA" is 1,6-hexanediol diacrylate. In the table, "NPGDA" in the multifunctional polymerizable compound stands for neopentyl glycol diacrylate. In the table, "PETA" in the polyfunctional polymerizable compound stands for pentaerythritol tetraacrylate. In the table, the polymerizable oligomer "O1" is 8UX-122A (acrylate oligomer manufactured by Taisei Fine Chemical Co., Ltd.). In the table, the polymerizable oligomer "O2" is CN9011 (acrylate oligomer manufactured by Sartomer Corporation). In the table, the polymerizable oligomer "O3" is CN996 (acrylate oligomer manufactured by Sartomer Corporation). In the table, the resin "R1" refers to Solvine CL (vinyl chloride-vinyl acetate copolymer resin, weight average molecular weight 25,000, manufactured by Nissin Chemical Industry Co., Ltd.). In the table, the resin "R2" is Daiso DAP (diallyl phthalate resin, weight average molecular weight 55,000, manufactured by Osaka Soda Co., Ltd.). In the table, the resin "R3" is Paraloid B60 (acrylic resin manufactured by Dow Chemical Company, weight average molecular weight 50,000). In the table, the polymerization initiator "compound (2-1)" is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. In the table, the polymerization initiator "compound (2-2)" is (2,4,6-trimethylbenzoyl)bis(p-tolyl)phosphine oxide. In the table, the polymerization initiator "compound (2-3)" is (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide. In the table, the polymerization initiator "compound (2-4)" is ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)phenylphosphinate. In the table, the polymerization initiator "compound (2-5)" is 1-(9,9-dibutyl-9H-fluoren-2-yl)-2-methyl-2-(morpholin-4-yl)propan-1-one. In the table, the polymerization initiator "compound (2-6)" is 4-benzoyl-4'-methyldiphenyl sulfide. In the table, the polymerization initiator "compound (2-7a)" is 2,4-diethylthioxanthen-9-one. In the table, the polymerization initiator "compound (2-7b)" is 2-isopropylthioxanthone. In the table, the polymerization initiator "Initiator 369" is 2-benzyl-2-(N,N-dimethylamino)-1-(4-morpholinophenyl)butan-1-one. In the table, the polymerization initiator "initiator TPO" is diphenyl-2,4,6-trimethylbenzoylphosphine oxide.

[0151] As can be seen from the above table, by using an ink composition containing a polymerizable compound represented by general formula (1), it is possible to form a cured film having high adhesion to various substrates such as acrylic resins.

[0152] In addition, although the ink composition of the examples does not contain a polymerization initiator that is a candidate for inclusion in Annex XIV of the REACH regulation enacted by the European Union as a substance of very high concern, it was confirmed that the ink composition had good curing properties.

[0153] The ink composition of Example 14 is obtained by further adding a binder resin to the ink composition of Example 1 and reducing the content of the polyfunctional polymerizable compound by the amount of the binder resin. The ink composition of Example 14, which contains such a predetermined amount of binder resin, is superior in curability, abrasion resistance, and adhesion to the ink composition of Example 1.

[0154] Similarly, the ink composition of Example 16 is obtained by adding a binder resin to the ink composition of Example 2 and reducing the content of the polymerizable oligomer by the amount of the resin content. The ink composition of Example 16, which contains such a predetermined amount of binder resin, is superior in curability, abrasion resistance, and adhesion to the ink composition of Example 2.

[0155] On the other hand, the ink compositions of the comparative examples that do not contain the polymerizable compound represented by general formula (1) are unable to form a cured film that has high adhesion to the acrylic resin substrate.

Claims

1. An active energy ray-curable ink composition that is discharged by an inkjet method, comprising: Contains a polymerizable compound, The polymerizable compound contains a polymerizable compound represented by the following general formula (1): Ink composition. 【Chemistry 1】 (In the formula, R １ is hydrogen or a methyl group, R 2 is hydrogen or an alkyl group having 1 to 10 carbon atoms which may be branched, R 3 is hydrogen or an alkyl group having 1 to 10 carbon atoms which may be branched.

2. The polymerizable compound represented by the general formula (1) is a liquid at 20° C. under 1 atmosphere. The ink composition according to claim 1 .

3. The polymerizable compound represented by the general formula (1) has a vapor pressure of 60 Pa or less at 20° C. The ink composition according to claim 2.

4. R in general formula (1) １ R ２ R ３ The total number of carbon atoms contained in is 3 or more. The ink composition according to claim 1 or 2.

5. Contains a binder resin having a weight average molecular weight of 10,000 or more, The content of the binder resin is 0.05% by mass or more and 25% by mass or less based on the total amount of the ink composition. The ink composition according to claim 1 or 2.

6. The ink composition according to claim 1 or 2, wherein the polymerizable compound contains a polyfunctional polymerizable compound, and the polyfunctional polymerizable compound having 4 or more functional groups accounts for 25 mass % or less of the total amount of the ink composition.

7. the total content of the binder resin and the polyfunctional polymerizable compound having 4 or more functional groups is 30 mass % or less of the total amount of the ink composition; The ink composition according to claim 6.

8. Contains coloring material, It may further contain a dispersant for dispersing the colorant. In the case where the dispersant is contained, the content of the dispersant is less than the content of the coloring material. The ink composition according to claim 1 or 2.

9. It hardens by the active energy rays emitted from the LED lamp. The ink composition according to claim 1 or 2.

10. An ink set comprising the ink composition according to claim 1 or 2.

11. A printed matter comprising the ink composition according to claim 1 or 2 printed on the surface of a substrate.

12. An ink jet recording device comprising a storage mechanism filled with the ink composition according to claim 1 or 2.

13. A recording method comprising ejecting the ink composition according to claim 1 or 2 by an ink-jet method.

14. 3. A method for producing a printed matter by discharging the ink composition according to claim 1 or 2 by an ink-jet method. A method for producing printed matter.

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