Active energy ray-curable composition

Abstract

To provide an active energy ray-curable composition having excellent curability and low yellowing properties and further having excellent storage stability and to provide a printed matter using the same.SOLUTION: There is provided an active energy ray-curable composition comprising a (meth)acrylate compound and a photopolymerization initiator, wherein the (meth)acrylate compound contains a (meth)acrylate compound having four or more (meth)acryloyl groups, the photopolymerization initiator contains an acylphosphine oxide compound having a melting point of 80 to 150°C and an acylphosphine oxide compound having a melting point of 25°C or less and the total content of the acylphosphine oxide compound is 1 to 25 mass% based on the total mass of the composition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an active energy ray-curable composition and printed matter used for packages and the like, and relates to an active energy ray-curable composition that is excellent in curability and storage stability and can provide printed matter that is excellent in low yellowing properties. [Background technology]

[0002] Active energy beam-curable inks are solvent-free and instantly dry when exposed to active energy beams. As such, they are environmentally friendly, have excellent printability, and produce high-quality printed matter. As a result, they are widely used in a range of fields, from printing information such as magazines and flyers to packaging for food packaging such as paper containers.

[0003] In recent years, in addition to conventional light sources such as high-pressure mercury lamps and metal halide lamps, various types of light sources have been used, such as light sources that use ozone-free metal halide lamps that do not generate ozone and generate ultraviolet rays of 230 to 420 nm, and light-emitting diode UV-LEDs that generate ultraviolet rays with an emission peak wavelength in the range of 350 to 420 nm. Although inventions have been made that combine multiple photopolymerization initiators with different absorption wavelengths that match the wavelength ranges of these various light sources, the current situation is that no composition that has sufficient curability and low yellowing is available (Patent Document 1).

[0004] Furthermore, as an example of providing an active energy ray-curable coating varnish that has excellent curing properties and is almost free of yellowing when exposed to ultraviolet light irradiated by a light-emitting diode that generates ultraviolet light with an emission peak wavelength in the range of 350 to 420 nm, an active energy ray-curable coating varnish that contains a compound having an ethylenic double bond, a photopolymerization initiator, and a fluorescent brightener, and is characterized in that the photopolymerization initiator is an acylphosphine oxide compound and a thioxanthone compound, has been mentioned; however, the storage stability of the varnish is insufficient (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7236578 [Patent Document 2] JP 2012-188659 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides an active energy ray-curable composition having excellent curability, low yellowing, and excellent storage stability, and a printed material using the same. [Means for solving the problem]

[0007] As a result of intensive research by the present inventors to solve the above problems, they found that the above problems can be solved by the active energy ray-curable composition shown below, and thus completed the present invention.

[0008] That is, the present invention provides an active energy ray-curable composition containing a (meth)acrylate compound and a photopolymerization initiator, The (meth)acrylate compound contains a (meth)acrylate compound having four or more (meth)acryloyl groups, The photopolymerization initiator contains an acylphosphine oxide compound having a melting point of 80 to 150°C and an acylphosphine oxide compound having a melting point of 25°C or lower, The present invention relates to an active energy ray-curable composition, in which the total content of the acylphosphine oxide compounds is 1 to 25 mass % based on the total mass of the composition.

[0009] The present invention also relates to the above active energy ray-curable composition, wherein the acylphosphine oxide compound having a melting point of 80 to 150° C. is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0010] The present invention also relates to the above active energy ray-curable composition, wherein the acylphosphine oxide compound having a melting point of 25° C. or lower is ethylphenyl(2,4,6-trimethylbenzoyl)phosphinate.

[0011] The present invention also relates to the above active energy ray-curable composition, wherein the photopolymerization initiator further contains a thioxanthone compound.

[0012] The present invention also relates to the above active energy ray-curable composition, wherein the content of the compound having four or more (meth)acryloyl groups is 5 to 60 mass % based on the total mass of the composition.

[0013] The present invention also relates to the above active energy ray-curable composition, wherein the content of the (meth)acryloyl group in the active energy ray-curable composition is 0.25 to 0.90 mol per 100 g of the active energy ray-curable composition.

[0014] The present invention also relates to the above active energy ray-curable composition, which further contains a fluorescent whitening agent.

[0015] The present invention also relates to the above-mentioned active energy ray-curable composition, which further contains a pigment as a colorant.

[0016] The present invention also relates to the above-mentioned active energy ray-curable composition for any printing selected from the group consisting of offset printing, resin letterpress printing, flexographic printing, and roll coater printing.

[0017] The present invention also relates to a laminate having a substrate and a cured product of the above-mentioned active energy ray-curable composition. Effect of the Invention

[0018] According to the present invention, it is possible to provide an active energy ray-curable composition having excellent curability, low yellowing property, and high storage stability, and a printed material using the same. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiment described below, and various modifications are possible without departing from the spirit and scope of the present invention.

[0020] The terms used in this specification are explained below. "(Meth)acrylate" means acrylate and / or methacrylate. "Active energy rays" means energy rays that have the property of causing chemical changes such as chemical reactions in objects irradiated with ultraviolet light. "PO" stands for "propylene oxide" and "EO" stands for "ethylene oxide."

[0021] <Active energy ray curable composition> The active energy ray-curable composition of the present invention contains a (meth)acrylate compound having at least four or more (meth)acryloyl groups, and two specific acylphosphine oxide compounds as photopolymerization initiators. Hereinafter, components that are or can be contained in the active energy ray-curable composition of the present embodiment (hereinafter also simply referred to as the "composition") will be described.

[0022] [(Meth)acrylate compounds] The composition of the present invention contains, as a (meth)acrylate compound, a (meth)acrylate compound having four or more (meth)acryloyl groups. The content of the compound having four or more (meth)acryloyl groups in the composition of the present invention is preferably from 5 to 60 mass %, and more preferably from 10 to 50 mass %, based on the total mass of the composition.

[0023] Specific examples of compounds having four or more (meth)acryloyl groups include tetrafunctional (meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate and ditrimethylolpropane tetra(meth)acrylate, pentafunctional (meth)acrylate compounds such as dipentaerythritol penta(meth)acrylate, and hexafunctional (meth)acrylate compounds such as dipentaerythritol hexa(meth)acrylate.

[0024] Furthermore, as the (meth)acrylate compound, a compound having 1 to 3 (meth)acryloyl groups can also be used.

[0025] Specific examples of the (meth)acrylate compound having 1 to 3 (meth)acryloyl groups include 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, β-carboxyethyl (meth)acrylate, 4-tert-butylcyclohexanol (meth)acrylate, tetrahydrofurfuryl acrylate, alkoxylated tetrahydrofurfuryl acrylate, caprolactone (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isoamyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, 3,3,5- Monofunctional (meth)acrylate compounds having one (meth)acryloyl group, such as trimethylcyclohexanol (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (oxyethyl) (meth)acrylate, 1,4-cyclohexanedimethanol (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, benzyl (meth)acrylate, EO-modified (2) nonylphenol acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, and acryloylmorpholine; 1,3-Butylene glycol di(meth)acrylate, 1,4-Butanediol di(meth)acrylate, 3-Methyl-1,5-pentanediol di(meth)acrylate, 1,6-Hexanediol di(meth)acrylate, 1,9-Nonanediol di(meth)acrylate, 1,10-Decanediol di(meth)acrylate, 1,2-Dodecanediol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, Polyethylene glycol (200) di(meth)acrylate, Polyethylene glycol (300) di(meth)acrylate, Polyethylene glycol (400) di(meth)acrylate, Polyethylene glycol (600) di(meth)acrylate, Hydroxypivalic acid neopentyl glycol di(meth)acrylate, Dipropylene glycol di(meth)acrylate (t) acrylate, tripropylene glycol di(meth)acrylate, EO-modified (2) 1,6-hexanediol di(meth)acrylate, PO-modified (2) neopentyl glycol di(meth)acrylate, (neopentyl glycol-modified) trimethylolpropane di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, EO-modified (4) bisphenol A di(meth)acrylate, PO-modified (4) bisphenol A di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, dicyclopentanyl di(meth)acrylate, and bifunctional (meth)acrylate compounds having two (meth)acryloyl groups, such as tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, Examples of the trifunctional (meth)acrylate compound having three (meth)acryloyl groups include trimethylolpropane tri(meth)acrylate, EO-modified (3) trimethylolpropane tri(meth)acrylate, PO-modified (3) trimethylolpropane tri(meth)acrylate, ε-caprolactone-modified tris-(2-acryloxyethyl)isocyanurate, ethoxylated isocyanuric acid tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, and pentaerythritol tri(meth)acrylate.

[0026] In addition, as the (meth)acrylate compound, urethane acrylate, polyester acrylate, epoxy acrylate, etc. can also be used.

[0027] Urethane acrylates include, for example, those obtained by reacting a diisocyanate with a (meth)acrylate having a hydroxyl group, and those obtained by reacting an isocyanate group-containing urethane prepolymer obtained by reacting a polyol with a polyisocyanate under conditions of an excess of isocyanate groups with a (meth)acrylate having a hydroxyl group, etc. Alternatively, they can also be obtained by reacting a hydroxyl group-containing urethane prepolymer obtained by reacting a polyol with a polyisocyanate under conditions of an excess of hydroxyl groups with a (meth)acrylate having an isocyanate group.

[0028] The polyester acrylate can be obtained, for example, by reacting a polyester polycarboxylic acid obtained by polycondensing a polybasic acid and a polyhydric alcohol with a hydroxyl group-containing (meth)acrylate or the like.

[0029] Examples of epoxy acrylates include those obtained by esterifying the glycidyl group of an epoxy resin with (meth)acrylic acid to convert the functional group into a (meth)acrylate group, such as a (meth)acrylic acid adduct of a bisphenol A type epoxy resin and a (meth)acrylic acid adduct of a novolac type epoxy resin.

[0030] In the present invention, the (meth)acrylate compounds may be used alone or in combination of two or more.

[0031] The composition of the present invention preferably has a (meth)acryloyl group content of 0.25 to 0.90 mol per 100 g of the composition. In this range, sufficient curability and sufficient storage stability can be achieved, and optimal printing can be performed. Furthermore, the (meth)acryloyl group content of the composition is preferably 0.28 to 0.80 mol per 100 g of the composition in order to ensure sufficient curability and optimal printability. The (meth)acryloyl group content (mol) in 100 g of the composition is a value calculated by using the molecular weight calculated from the structure of the (meth)acrylate compound and the number of moles of (meth)acryloyl groups per 100 g of the composition.

[0032] [Photopolymerization initiator] The composition of the present invention contains a photopolymerization initiator. The polymerization initiator in the present invention is a compound that undergoes a chemical change and generates radicals through the action of light or through interaction with the electronically excited state of the sensitizing dye, and among them, a photoradical polymerization initiator is preferable from the viewpoint of being able to initiate polymerization by exposure to light.

[0033] The composition of the present invention contains, as a photopolymerization initiator, an acylphosphine oxide compound having a melting point of 80 to 150° C., and an acylphosphine oxide compound having a melting point of 25° C. or lower.

[0034] Furthermore, in order to ensure sufficient curability, excellent low yellowing properties, and storage stability, the total content of the acylphosphine oxide compounds is preferably 1 to 25 mass % based on the total mass of the composition, and more preferably 3 to 18 mass % based on the total mass of the composition.

[0035] Examples of the acylphosphine oxide compound having a melting point of 80 to 150°C include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (melting point: 91°C), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (melting point: 127°C), and 2,4,6-trimethylbenzoyl-bis(4-methylphenyl)phosphinyl oxide (melting point: 122°C). Of these, it is preferable to use those having a melting point of 100 to 150° C., and it is particularly preferable to use bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0036] An example of an acylphosphine oxide compound having a melting point of 25° C. or lower is ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (melting point: −12° C.). Among these, those having a melting point of −50 to 25° C. are preferably used, and ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is more preferably used.

[0037] It is also preferable to use a thioxanthone compound as the photopolymerization initiator, since the use of a thioxanthone compound can provide even more sufficient curability.

[0038] Examples of thioxanthone compounds include 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, and 2,4-diethylthioxanthone.

[0039] In addition, photopolymerization initiators other than those mentioned above can also be used as the photopolymerization initiator. Specific examples include benzophenone compounds, dialkoxyacetophenone compounds, α-hydroxyalkylphenone compounds, and α-aminoalkylphenone compounds.

[0040] Benzophenone compounds include benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, [4-(methylphenylthio)phenyl]-phenylmethanone, and the like.

[0041] Examples of the dialkoxyacetophenone compounds include 2,2-dimethoxy-2-phenylacetophenone, dimethoxyacetophenone, and diethoxyacetophenone.

[0042] Examples of α-hydroxyalkylphenone compounds include 1-hydroxy-cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxymethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl]-2-methyl-propan-1-one.

[0043] Examples of α-aminoalkylphenone compounds include 2-methyl-1-[4-(methoxythio)-phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl-1-butanone.

[0044] In the present invention, the two types of acylphosphine oxide compounds may be used alone or in combination with other photopolymerization initiators. The other photopolymerization initiators may be used alone or in combination with two or more.

[0045] When the composition of the present invention is cured by irradiating it with ultraviolet light, it is sufficient to add a photopolymerization initiator to the composition. In order to further improve the curability, a photosensitizer can also be used in combination. Examples of photosensitizers include amines such as triethanolamine, methyldiethanolamine, dimethylethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino)ethyl benzoate, (n-butoxy)ethyl 4-dimethylaminobenzoate, and 2-ethylhexyl 4-dimethylaminobenzoate.

[0046] [resin] The composition of the present invention may contain a resin in order to improve the curability.

[0047] The resin in the present invention is preferably one having excellent compatibility with the (meth)acrylate compound, and examples thereof include diallyl phthalate resin, rosin-modified resin, polyvinyl chloride, poly(meth)acrylic acid ester, epoxy resin, polyester resin, polyurethane resin, cellulose derivatives (e.g., ethyl cellulose, cellulose acetate, nitrocellulose), vinyl chloride-vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, alkyd resin, petroleum resin, urea resin, and synthetic rubber such as butadiene-acrylonitrile copolymer.

[0048] [Fluorescent whitening agent]

[0049] The fluorescent brightening agent used in the present invention is capable of selectively absorbing ultraviolet light, converting it to purple to blue light (visible light), and emitting light. That is, the fluorescent brightening agent of the present invention may be a fluorescent coloring agent, and is not particularly limited as long as it changes from a ground state to an excited state when absorbing ultraviolet light, preferably 315 nm to 450 nm, more preferably 350 nm to 410 nm, and emits light from a colorless state to a colored state, and any of fluorescent coloring agents, fluorescent brightening agents, etc. may be used, and may be a dye or a pigment.

[0050] Examples of the compound include benzoxazoles, oxazoles, stilbenes, coumarins, pyrazolines, imidazoles, naphthalimides, bisbenzoxazoles, and bisstyrylbiphenyls, as well as diaminostilbene disulfonic acid derivatives.

[0051] Specifically, 2,5-thiophenediylbis-(5-tert-butyl-1,3-benzoxazole), benzoxazole-2,2'-(2,5-thiophenediyl)-bis-[5-(1,1-dimethylethyl)], 2,2'-(1,2-ethenediyldi-4,1-phenylene)bis-benzoxazole, 2,2'-(2,5-thiophenediyl)bis-(5-tert-butylbenzoxazole)1,4,5,8 -Naphthalene-tetracarboxylic acid imide, 2,5-diaryl-1,3,4-oxadiazole, 2,2'-bis-(5-phenyl-1,3,4-oxadiazole), 3-phenyl-7-(4-methyl-6-butyloxybenzoxazole)coumarin, 4,4'-bis(benzoxazol-2-yl)stilbene, 4-methyl-7-diethylaminocoumarin, 2,4-dimethoxy-6-(1'-pyrenyl)1,3,5-trimethyl-2,4-diphenyl- ... riazine, 1,4-bis(benzoxazol-2-yl)naphthalene, 4,4'-bis(benzoxazol-2-yl)stilbene, 4-(benzoxazol-2-yl)-4'-(5-methylbenzoxazol-2-yl)stilbene, 4,4'-bis-(5-methylbenzoxazol-2-yl)stilbene, 3-phenyl-7-(2H-naphtho-[[1,2-d]]triazol-2-yl)coumarin, 4,4'-bis (2-methytoxystyryl)-biphenyl, 2,5-bis-(5-tert-butylbenzoxazol-2-yl)thiophene, and 1,1'-biphenyl-4,4'-bis-(2-(methoxyphenyl)ethenyl). In particular, bisbenzoxazole compounds are preferred, and 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole), a compound represented by general formula (1), is more preferred.

[0052] The amount of the fluorescent whitening agent added is preferably 0.01 to 5% by mass based on the total mass of the composition. When the amount added is within this range, the color development and solubility when irradiated with ultraviolet light are good.

[0053] <Photopolymerization inhibitor> The composition of the present invention may contain a photopolymerization inhibitor, which can provide excellent storage stability.

[0054] From the viewpoint of storage stability, the photopolymerization inhibitor in the present invention preferably contains one type selected from the group consisting of nitroso compounds, phenolic compounds, quinone compounds, and piperidine compounds, and more preferably contains two or more types selected from the group consisting of nitroso compounds, phenolic compounds, quinone compounds, and piperidine compounds.

[0055] Examples of nitroso compounds include nitrosobenzene, aluminum N-nitrosophenylhydroxylamine, tri-p-nitrophenylmethyl, picric acid, cupferron, butyraldoxime, methyl ethyl ketoxime, and cyclohexanone oxime.

[0056] Examples of the phenol-based compounds include (alkyl)phenols, p-methoxyphenol, o-isopropylphenol, catechol, resorcin, t-butylcatechol, pyrogallol, dibutylcresol, and guaiacol.

[0057] Examples of quinone compounds include hydroquinone, t-butylhydroquinone, p-benzoquinone, and 2,5-di-tert-butyl-p-benzoquinone.

[0058] Examples of the piperidine compounds include phenothiazine.

[0059] In addition, the photopolymerization inhibitor in the present invention may be used in combination with photopolymerization inhibitors other than the above-mentioned nitroso compounds, phenolic compounds, quinone compounds, and piperidine compounds (also referred to as "other photopolymerization inhibitors"). Specific examples of other photopolymerization inhibitors include 1,1-picrylhydrazyl, dithiobenzoyl disulfide, N-(3-oxyanilino-1,3-dimethylbutylidene)aniline oxide, cyclohexanone oxime cresol, and the like.

[0060] The content of the photopolymerization inhibitor is preferably from 0.05 to 5.0% by mass, and more preferably from 0.1 to 1.0% by mass, based on the total mass of the composition.

[0061] [Coloring agent] A colorant may be used in the composition of the present invention. As the colorant, at least one of a pigment and a dye may be used, but from the viewpoint of light resistance, it is preferable to use a pigment.

[0062] The pigment in the present invention is not particularly limited, and any known pigment can be used. Both inorganic and organic pigments can be used.

[0063] Examples of inorganic pigments include carbon blacks such as furnace black, lamp black, acetylene black, and channel black, iron oxide, and titanium oxide.

[0064] Examples of organic pigments include soluble azo pigments such as β-naphthol, β-oxynaphthoic acid, β-oxynaphthoic acid anilide, acetoacetate anilide, and pyrazolone; Examples of the pigments include insoluble azo pigments such as β-naphthol, β-oxynaphthoic acid anilide, acetoacetate anilide monoazo, acetoacetate anilide disazo, and pyrazolone pigments; phthalocyanine pigments such as copper phthalocyanine blue, halogenated (e.g., chlorinated or brominated) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, and metal-free phthalocyanine; and polycyclic pigments and heterocyclic pigments such as quinacridone, dioxazine, threne (pyranthrone, anthranthrone, indanthrone, anthrapyrimidine, flavanthrone, thioindigo, anthraquinone, perinone, perylene, etc.), isoindolinone, metal complex, quinophthalone, and diketopyrrolopyrrole.

[0065] More specifically, in terms of the CI color index, black pigments include CI Pigment Black 1, 6, 7, 9, 10, 11, 28, 26, 31, and the like.

[0066] Examples of white pigments include CI Pigment White 5, 6, 7, 12, and 28.

[0067] Examples of yellow pigments include CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 18, 24, 73, 74, 75, 83, 93, 95, 97, 98, 100, 108, 109, 110, 114, 120, 128, 129, 138, 139, 174, 150, 151, 154, 155, 167, 180, 185, and 213.

[0068] Blue or cyan pigments include CI Pigment Blue 1, 2, 14, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and the like.

[0069] Red or crimson pigments include CI Pigment RED 1, 3, 5, 19, 21, 22, 31, 38, 42, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 50, 52, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 83, 90, 104, 108, 11 2, 114, 122, 144, 146, 148, 149, 150, 166, 168, 169, 170, 172, 173, 176, 177, 178, 184, 185, 187, 193, 202, 209, 214, 242, 254, 255, 264, 266, 269, CI Pigment Violet 19, etc.

[0070] Green pigments include CI Pigment Green 1, 2, 3, 4, 7, 8, 10, 15, 17, 26, 36, 45, 50, and the like.

[0071] Purple pigments include CI Pigment Violet 1, 2, 3, 4, 5:1, 12, 13, 15, 16, 17, 19, 23, 25, 29, 31, 32, 36, 37, 39, and 42. Orange pigments include CI Pigment Orange 13, 16, 20, 34, 36, 38, 39, 43, 51, 61, 63, 64, 74, and the like.

[0072] In the present invention, the above pigments may be used alone or in combination of two or more.

[0073] The colorant in the present invention can be used in any content as long as the desired concentration can be reproduced, and is preferably used in an amount of 5 to 30 mass % and more preferably 10 to 25 mass % based on the total mass of the composition.

[0074] [Extender pigment] An extender pigment may be added to the composition of the present invention. As the body pigment in the present invention, inorganic fine particles are preferably used.

[0075] Specific examples of extender pigments include inorganic extender pigments such as lime carbonate powder, precipitated calcium carbonate, precipitated barium sulfate, gypsum, clay (China clay), silica, diatomaceous earth, talc, kaolin, alumina white, barium sulfate, aluminum stearate, calcium stearate, calcium carbonate, magnesium carbonate, barite powder, abrasive powder, etc., as well as silicone, glass beads, etc. These inorganic fine particles can add effects such as adjusting the flowability of the composition, preventing misting, and preventing penetration into printing substrates such as paper.

[0076] [Additives] Depending on the purpose, the composition of the present invention may further contain various additives such as an anti-friction agent, an anti-blocking agent, a slipping agent, etc. Various additives can be added to the composition by a conventional method. When various additives are added to the composition of the present invention, it is preferable to adjust the amount of each additive to a range that does not inhibit the effects of other materials. The amount of each additive is preferably 15 mass % or less of the total amount of the composition.

[0077] In this specification, the active energy rays typically include ultraviolet rays, electron beams, X-rays, ionizing radiation such as α-rays, β-rays, and γ-rays, microwaves, high frequency waves, and the like, but may be any energy species capable of generating radical active species, including visible light, infrared light, and laser beams. Examples of devices that emit ultraviolet rays include LEDs, ultra-high pressure mercury lamps, high pressure mercury lamps, medium pressure mercury lamps, low pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, helium-cadmium lasers, YAG lasers, excimer lasers, and argon lasers.

[0078] The composition of the present invention can be applied to various substrates and printed materials such as various printed materials for books, various printed materials for packaging such as paper, various printed materials for plastics, printed materials for stickers / labels, fine art printed materials, and printed materials for metals (fine art printed materials, printed materials for beverage cans, printed materials for canned food such as canned foods).

[0079] <Laminate> The laminate of the present invention is obtained by printing or coating the composition of the present invention on a substrate and curing it with active energy rays. There is no particular limitation on the substrate, and any known substrate can be used. Specific examples include coated paper such as art paper, coated paper, and cast paper, uncoated paper such as fine paper, medium-quality paper, and newsprint, synthetic paper such as Yupo paper, and plastic films such as PET (polyethylene terephthalate), PP (polypropylene), and OPP (biaxially oriented polypropylene).

[0080] Methods for printing or coating the composition of the present invention on a substrate include a roll coater, a gravure coater, a flexo coater, an air doctor coater, a blade coater, an air knife coater, a squeeze coater, an impregnation coater, a transfer roll coater, a kiss coater, a curtain coater, a cast coater, a spray coater, a die coater, offset printing (normal lithographic printing using dampening water and waterless lithographic printing not using dampening water), flexo printing, gravure printing, screen printing, and the like. EXAMPLES

[0081] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the present specification, "parts" refers to parts by mass, and "%" refers to % by mass.

[0082] Details of the various measurements carried out in the following examples are as follows.

[0083] Example 1 [Production of active energy ray-curable composition 1] (for flexographic printing and roll coater printing) As (meth)acrylate compounds, 42.6 parts of MIRAMERM3130 and 45.0 parts of MIRAMERM600, as photopolymerization initiators, 1.0 part of Omnirad 819 and 10.0 parts of Omnirad TPO-L, as photopolymerization inhibitors, 0.3 part of H-BHT and 0.1 part of Polystop 7300P, as well as 1.0 part of fatty acid ester as an additive, were added and thoroughly mixed using a disperser to prepare active energy ray curable composition 1.

[0084] Examples 2-17, Comparative Examples 1-8 [Production of active energy ray curable compositions 2 to 25] (for flexographic printing and roll coater printing) Except for changing the raw materials and amounts thereof shown in Table 1, active energy ray-curable compositions 2 to 25 were obtained in the same manner as active energy ray-curable composition 1. Note that the numerical values ​​in the table represent "parts by mass" unless otherwise specified, and blank spaces represent no blend.

[0085] Example 18 [Production of active energy ray curable composition 26] (for offset printing, resin letterpress printing) As (meth)acrylate compounds, 29.8 parts of MIRAMER M240, 5.0 parts of MIRAMER M3130, 8.0 parts of MIRAMER M410, 7.0 parts of MIRAMER M600, and 20.0 parts of MIRAMER PE210 were used. As photopolymerization initiators, 1.0 part of Omnirad 819 and 1.0 part of Omnirad 6.0 parts of TPO-L, 0.1 parts of Q-1301 and 0.1 parts of TBHQ as photopolymerization inhibitors, 7.0 parts of DAP-A as resins, 1.0 parts of fatty acid ester, 3.0 parts of WAX, and 2.0 parts of Fine Oxocol 180 as additives, 1.0 part of High Filler 5000PJ and 9.0 parts of Reolosil MT-10C as extender pigments, were added and stirred and mixed using a mixer, and dispersed using a three-roll mill so that the maximum particle size was 15 μm or less, to prepare active energy ray-curable composition 26.

[0086] Examples 19-35, Comparative Examples 9-15 [Production of active energy ray curable compositions 27 to 50] (for offset printing and resin letterpress printing) Except for changing the raw materials and amounts thereof shown in Table 2, active energy ray-curable compositions 27 to 50 were obtained in the same manner as active energy ray-curable composition 26. Note that the numerical values ​​in the table represent "parts by mass" unless otherwise specified, and blank spaces represent no blend.

[0087] [Table 1]

[0088] [Table 1]

[0089] [Table 1]

[0090] [Table 2]

[0091] [Table 2]

[0092] [Table 2]

[0093] The methods for producing the above active energy ray-curable compositions 1 and 26 and the abbreviations in Tables 1 and 2 are as follows. [(Meth)acrylate compounds] · MIRAMER M216: MIWON, neopentyl glycol PO modified diacrylate, molecular weight 328 · MIRAMER M3130: MIWON, trimethylolpropane EO modified triacrylate, molecular weight 428 Ebecryl OTA480: Glycerol propoxy triacrylate, molecular weight 428, manufactured by Daicel-Orkunex Corporation MIRAMER M410: MIWON, ditrimethylolpropane tetraacrylate, molecular weight 482 MIRAMER M600: MIWON, dipentaerythritol hexaacrylate, molecular weight 578.6 MIRAMER M240: MIWON, bisphenol AEO modified diacrylate, molecular weight 512.59 MIRAMER PE210: MIWON, bisphenol A epoxy diacrylate, molecular weight 520 [Photopolymerization initiator] OmniradTPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide, melting point 91°C Omnirad819: Bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide, melting point 127°C OmniradTPO-L: Ethoxyphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, melting point -12°C Ltcure TMO: (Di-p-tolylphosphoryl)(mesityl)methanone manufactured by PiChem, melting point 122°C Omnirad4MBZ: 4-Methylbenzophenone OmniradDETX: 2,4-diethylthioxanthone, manufactured by IGM Omnirad1173: IGM, 2-hydroxy-2-methyl-1-phenyl-1-propanone Amino alcohol MDA: Nippon Nyukazai Co., Ltd., N-methyldiethanolamine [Fluorescent whitening agent] Tinopal OBCO: 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole) manufactured by BASF Japan [resin] DAP-A: Diallyl phthalate resin, manufactured by Osaka Soda Co., Ltd. [Extender pigment] - Leoloseal MT-10C: Tokuyama Corporation, silica · Hi-Filler 5000PJ: Matsumura Sangyo Co., Ltd.: Talc [Photopolymerization inhibitor] H-BHT: Honshu Chemical Industry Co., Ltd., dibutyl hydroxytoluene Polystop 7300P: Manufactured by Hakuto Co., Ltd., piperidine compounds, piperidine derivatives Q-1301: Fujifilm Wako Pure Chemical Industries, Ltd., nitroso-based compound, N-nitrosophenylhydroxylamine aluminum salt TBHQ: Manufactured by Seiko Chemical Co., Ltd., phenolic compound, 2-t-butylhydroquinone [Additives] Fatty acid ester: ADEKALUBE F-3HH WAX: Sanyo Chemical Industries Sanwax 161P polyethylene resin Fine Oxocol 180: Nissan Chemical Co., Ltd. Isooctadecyl alcohol leveling agent

[0094] [Evaluation of active energy ray-curable composition] The obtained active energy ray-curable compositions 1 to 50 were evaluated according to the following methods. The results of each evaluation are shown in Tables 1 and 2.

[0095] [Curability] (How to prepare hardening test specimens - 1) For the obtained active energy ray curable compositions 1 to 25, black ink FD Karton X (active energy ray curable ink manufactured by Toyo Ink Co., Ltd.) was printed on Hokuetsu Maricoat (coated cardboard manufactured by Hokuetsu Corporation), and the active energy ray curable composition shown in Table 1 was applied onto the cured ink layer using a bar coater #2. After that, ultraviolet rays were irradiated using an LED curing device manufactured by AMS (wavelength 385 nm) at a conveyor speed of 50 m / min, and the printed surface was completely dried. (How to prepare hardening test specimens - 2) For the obtained active energy ray curable compositions 26 to 50, black ink FD Karton X (active energy ray curable ink manufactured by Toyo Ink Co., Ltd.) was printed on Hokuetsu Maricoat (coated cardboard manufactured by Hokuetsu Corporation), and a colored product was prepared on the cured ink layer using an RI Tester (manufactured by Tester Sangyo Co., Ltd.) with a 4-split roll and an ink amount of 0.075 ml. After that, ultraviolet rays were irradiated using an AMS LED curing device (385 nm) at a conveyor speed of 50 m / min to completely dry the printed surface.

[0096] The test piece prepared by the above method was used to rub the printed surface and evaluate it. The less rubbing, the better the curability. The evaluation criteria are as shown below, with ⊚ and ◯ being practically preferable. ◎: No rubbing on the printed surface ○: The surface of the printed surface is rubbed off △: Scratched to the middle of the printed surface ×: Scraped down to the bottom of the printed surface

[0097] [Yellowing] (How to prepare hardening test specimens - 3) For the obtained active energy ray curable compositions 1 to 25, the active energy ray curable composition shown in Table 1 was applied to Hokuetsu Maricoat (coated cardboard manufactured by Hokuetsu Corporation) using a bar coater #2. After that, ultraviolet rays were irradiated using an AMS LED curing device (wavelength 385 nm) at a conveyor speed of 50 m / min, and the printed surface was completely dried. (How to prepare hardening test specimens - 4) For the obtained active energy ray curable compositions 26 to 50, a colored product was prepared on Hokuetsu Maricoat (coated cardboard manufactured by Hokuetsu Corporation) using an RI tester (manufactured by Tester Sangyo Co., Ltd.) with a 4-split roll and an ink amount of 0.075 ml. After that, the printed surface was irradiated with ultraviolet light using an AMS LED curing device (385 nm) at a conveyor speed of 50 m / min to completely dry the printed surface.

[0098] Using the test piece prepared by the above method, the b-value of the printed surface was measured with an X-rite spectrophotometer to confirm the difference in b-value between the paper alone and the printed surface. The evaluation criteria are as shown below, with ⊚ and ◯ being practically preferable. ◎: The difference in b value between the paper only and the printed surface is 0 or more and less than 3.0 ○: The difference in b value between the paper only and the printed surface is 3 or more and less than 5.0 △: The difference in b value between the paper only and the printed surface is 5.0 or more and less than 7.0 ×: The difference in b-value between the paper only and the printed surface is 7.0 or more.

[0099] [Yellowing-2]

[0100] The test pieces prepared by the above method were irradiated with black light (a light source having an emission wavelength range of 325 nm and 365 nm) and the whiteness was evaluated visually. The evaluation was carried out on a four-level scale of ⊚ (good), ◯, △, and × (bad), with ⊚ and ◯ being preferred in practical use.

[0101] [Stability-1] A metal container was filled with 100 ml of the active energy ray-curable composition, sealed, and stored at 10° C., 25° C., and 60° C. After 6 months, the composition was removed and the viscosity was measured using a Thermo Scientific HAAKE Rheo Stress 6000, and the ratio to the viscosity before the start of the test was calculated. The evaluation criteria are as shown below, with ◎ and ◯ being practically preferable. ◎: Viscosity increase rate is less than 120% compared to viscosity before the test ○: Viscosity increase rate compared to viscosity before the test is 120% or more but less than 150% △: Viscosity increase rate compared to viscosity before the test is 150% or more but less than 180% ×: Viscosity increase rate is 200% or more compared to viscosity before the test [Stability-2] A metallic container was filled with 100 ml of the active energy ray-curable composition, sealed, and stored at 10° C., 25° C., and 60° C. After six months, the composition was taken out and the maximum particle size was confirmed. ⊚ and ◯ are practically preferable. ◎: Less than 0 to 15 μm. ○: Less than 15 μm to 25 μm. △: Less than 25 μm to 50 μm. ×: 50 μm or more.

[0102] [Stability] Based on a combination of the above two stability evaluations, if all of the evaluations in [Stability-1] and [Stability-2] are favorable for practical use (◎, ◯), the stability is judged to be ◯ (good). If either of the above evaluations is judged to be poor for practical use (△, ×), the stability is judged to be × (poor).

[0103] As shown in Tables 1 and 2, Examples 1 to 35 were good in terms of curability, yellowing, and stability, and had no practical problems. On the other hand, Comparative Examples 1 and 9 did not contain an acylphosphine oxide compound and had insufficient curing properties. Comparative Examples 2, 3, 10, 11, and 12 used one type of acylphosphine oxide compound with a melting point of 80 to 150°C and had insufficient stability. In Comparative Examples 4 and 13, one type of acylphosphine oxide compound having a melting point of 25° C. or lower was used, and the curability was insufficient. In Comparative Example 7, the amount of photopolymerization initiator was too large, and thus the yellowing was insufficient. In Comparative Examples 5, 6, 8, 14, and 15, the content of the (meth)acrylate compound having four or more (meth)acryloyl groups was insufficient, and thus the curability was insufficient.

Claims

1. An active energy ray-curable composition comprising a (meth)acrylate compound and a photopolymerization initiator, The (meth)acrylate compound contains a (meth)acrylate compound having four or more (meth)acryloyl groups, the photopolymerization initiator contains an acylphosphine oxide compound having a melting point of 80 to 150°C and an acylphosphine oxide compound having a melting point of 25°C or lower; An active energy ray-curable composition, wherein the total content of acylphosphine oxide compounds is 1 to 25 mass % based on the total mass of the composition.

2. 2. The active energy ray-curable composition according to claim 1, wherein the acylphosphine oxide compound having a melting point of 80 to 150° C. is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

3. 2. The active energy ray-curable composition according to claim 1, wherein the acylphosphine oxide compound having a melting point of 25° C. or lower is ethylphenyl(2,4,6-trimethylbenzoyl)phosphinate.

4. 2. The active energy ray-curable composition according to claim 1, wherein the photopolymerization initiator further contains a thioxanthone compound.

5. 2. The active energy ray-curable composition according to claim 1, wherein the content of the compound having four or more (meth)acryloyl groups is 5 to 60 mass % based on the total mass of the composition.

6. 2. The active energy ray-curable composition according to claim 1, wherein the content of the (meth)acryloyl group in the active energy ray-curable composition is 0.25 to 0.90 mol per 100 g of the active energy ray-curable composition.

7. The active energy ray-curable composition according to claim 1 , further comprising a fluorescent whitening agent.

8. The active energy ray-curable composition according to claim 1 , further comprising a pigment as a colorant.

9. 2. The active energy ray-curable composition according to claim 1, which is for any printing selected from the group consisting of offset printing, resin letterpress printing, flexographic printing, and roll coater printing.

10. A laminate having a substrate and a cured product of the active energy ray-curable composition according to any one of claims 1 to 9.

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