Electron beam curable printing ink composition and printed matter obtained by printing with the electron beam curable printing ink composition

Abstract

To provide an electron beam-curable printing ink composition which has sufficient properties such as adhesion, scratch resistance and heat resistance after printed, in spite of not containing a conventional polymerization initiator.SOLUTION: The composition contains a pigment, a curable resin, a compound of the general formula in the figure, and dimethylpolysiloxane.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an electron beam curable printing ink composition and a printed matter obtained by printing with the electron beam curable printing ink composition. [Background technology]

[0002] With the goal of protecting the global environment, various industries and sectors are carrying out activities to reduce their environmental impact, and activities to promote environmental impact reduction are being carried out from various perspectives. For example, volatile organic compounds (VOCs) contained in paints and inks are chemical substances that lead to global warming, so activities to reduce environmental impact are being carried out by voluntarily restricting and reducing the use of VOCs. From the viewpoint of reducing VOCs, the use of active energy ray-curable printing ink compositions that are cured by active energy rays such as ultraviolet rays and electron beams is being considered. Active energy ray-curable printing ink compositions contain a polymerizable compound that polymerizes when irradiated with active energy rays, and a polymerization initiator that exhibits polymerization initiation function when irradiated with active energy rays. Active energy ray-curable compositions reduce the amount of VOC used and, in turn, eliminate or reduce the amount of VOC volatilized into the atmosphere, thereby enabling a reduction in the environmental impact. Furthermore, because they cure rapidly (have fast-drying properties), they can save energy and improve productivity, and therefore have actually been used as compositions for paints and printing inks.

[0003] In the printing industry, if the ink on the surface of printed materials printed using various methods is not dried sufficiently, it will bleed through when the printed materials are stacked, or the ink will stick to fingers that touch the printed material.As a result, if the printed material is not dried sufficiently, it cannot be sent to the next process or distributed as a product.For this reason, actinic energy ray-curable inks, which can instantly harden (dry) the ink on the surface of the printed material by irradiating the printed material with actinic energy rays immediately after printing, are becoming popular. Such active energy ray-curable inks are widely known, as described in, for example, Patent Documents 1 and 2.

[0004] Furthermore, various efforts are being made to reduce the environmental impact of actinic radiation-curable printing ink compositions, such as the development of products that can be cured (dried) with less actinic radiation exposure, and the replacement of high-pressure mercury lamps, which consume a lot of power and generate ozone due to their short-wavelength ultraviolet rays, with UV LED lamps and low-output UV lamps that save energy and generate less ozone.

[0005] Furthermore, it may be preferable to reduce the amount of polymerization initiator used in the ink composition, and as described above, active energy ray-curable printing ink compositions have been made to contain polymerization initiators that have the property of extremely easily generating radicals. For example, as described in Patent Document 1, it is known that a photopolymerization initiator must be blended into an ultraviolet-curable inkjet ink composition, and that various surfactants, including various silicone surfactants such as unmodified silicone oil and modified silicone oil, can be blended as optional components. Furthermore, as described in Patent Document 2, it is essential that a photopolymerization initiator be blended into an ultraviolet-curable inkjet ink composition, and it is known that various surfactants, including various silicone surfactants such as modified silicone oils other than unmodified silicone oils, can be blended as optional components. However, such an actinic ray-curable printing ink composition that does not contain a polymerization initiator and that can be used in a wide range of printing formats, compositions, and applications has not yet been put to practical use. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-178832 [Patent Document 2] Japanese Patent Application Publication No. 2018-86726 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electron beam-curable printing ink composition that, after printing, sufficiently combines basic properties such as adhesion, scratch resistance, and heat resistance, even without containing a conventional polymerization initiator. [Means for solving the problem]

[0008] The present inventors have found that the above problems can be solved by preparing the following electron beam-curable printing ink composition, and have thus achieved the present invention. 1. An electron beam-curable printing ink composition comprising a pigment, a curable resin, a compound represented by general formula (1) and / or general formula (2), and dimethylpolysiloxane, wherein the compound represented by general formula (1) and / or general formula (2) is contained in a total amount of 1.0 to 80.0 mass% and the dimethylpolysiloxane is contained in a total amount of 0.01 to 10.0 mass% based on the total mass of the composition. JPEG0007785466000001.jpg73132 General formula (1) Each R is independently -CH2-CH2-O- or -CH2-CH(CH3)-O- l+m+n=3~21 JPEG0007785466000002.jpg106158 General formula (2) R is -CH2-CH(CH3)-O- l+m+n=3~21 2. The electron beam curable printing ink composition according to 1, which contains a polyester acrylate oligomer as the curable resin. 3. A printed matter obtained by printing with the electron beam curable printing ink composition described in 1 or 2. [Effects of the Invention]

[0009] According to the present invention, it is possible to obtain an electron beam-curable printing ink composition that satisfies basic properties such as adhesion, scratch resistance, and heat resistance without containing a polymerization initiator such as a photopolymerization initiator, and it is also possible to increase the proportion of biomass-derived raw materials. Furthermore, it is possible to prevent a decrease in stability due to the inclusion of a polymerization initiator. When used for lamination, it exhibits excellent lamination suitability. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the electron beam curable printing ink composition of the present invention will be used in the same applications as conventional printed materials. The curable resin in the present invention refers to an oligomer or a polymer. The curable component in this specification refers to all components that react and cure, such as a monomer, in addition to an oligomer or a polymer. The electron beam curable printing ink composition of the present invention contains a resin component, a pigment, additives, and, if necessary, a solvent, etc., in the same manner as common printing inks. The ink composition can be used as a printing ink regardless of the printing method, and can be adopted in known methods that use ink compositions that are cured by irradiation with electron beams, such as flexography, gravure, and inkjet.The ink composition can also be used without limiting the printing medium. The electron beam curable printing ink composition of the present invention may also be simply referred to as an ink composition. Furthermore, "in the solid content" means the total solid content of the component to be cured, including the component cured by electron beam irradiation and the solid content that is already solid or dissolved before curing. Furthermore, since the composition of the curable resin is not important, raw materials derived from biomass can be actively used.

[0011] [Curable resin] The curable resin component contained in the electron beam-curable printing ink composition of the present invention can be one or more oligomers and polymers that have unsaturated bonds and cure to form a resin. These curable resins preferably account for 20.0% by mass or more of the solid content of the electron beam-curable printing ink composition, more preferably 30.0% by mass or more, and even more preferably 40.0% by mass or more. Similarly, they preferably account for 90.0% by mass or less of the solid content, more preferably 85.0% by mass or less, and even more preferably 80.0% by mass or less. If the content is less than 20.0% by mass, the curability of the electron beam-curable printing ink composition as a whole may be impaired, while if it exceeds 90.0% by mass, the ink composition may be difficult to handle. However, the curable resin must be a resin component that can undergo a radical polymerization reaction with the radicals generated by the electron beam, and the following can be used, for example:

[0012] (oligomer) Oligomers are components that undergo polymerization of ethylenically unsaturated bonds within the molecule to achieve a high molecular weight. Because they are inherently relatively high molecular weight components, they are also used to impart appropriate viscosity and elasticity to ink compositions. Furthermore, because oligomers have a relatively high polarity, they can also be expected to impart adhesion to non-absorbent media to the cured ink composition. The content of the oligomer relative to the total curable components is preferably 20.0% by mass or more, more preferably 30.0% by mass or more, and even more preferably 35.0% by mass or more, and is preferably 60.0% by mass or less, more preferably 55.0% by mass or less, and even more preferably 50.0% by mass or less. Examples of this oligomer include epoxy-modified (meth)acrylates, exemplified by esters of (meth)acrylic acid with a hydroxyl group generated after ring-opening of an epoxy group contained in an epoxy compound such as an epoxy resin with an acid or base; rosin-modified epoxy acrylates; polyester-modified (meth)acrylates, exemplified by esters of (meth)acrylic acid with a terminal hydroxyl group of a condensation polymer of a dibasic acid and a diol; polyether-modified (meth)acrylates, exemplified by esters of (meth)acrylic acid with a terminal hydroxyl group of a polyether compound; and urethane-modified (meth)acrylates, exemplified by esters of (meth)acrylic acid with a terminal hydroxyl group in a condensation polymer of a polyisocyanate compound and a polyol compound. Examples of such polymers or oligomers having an ethylenically unsaturated bond include polydiallyl phthalate, neopentyl glycol oligo(meth)acrylate, 1,4-butanediol oligo(meth)acrylate, 1,6-hexanediol oligo(meth)acrylate, trimethylolpropane oligo(meth)acrylate, pentaerythritol oligo(meth)acrylate, urethane(meth)acrylate, epoxy(meth)acrylate, polyester(meth)acrylate, epoxy(meth)acrylate, rosin-modified epoxy(meth)acrylate, unsaturated polyester, polyether(meth)acrylate, acrylic resins having unreacted unsaturated groups, unsaturated polyethers, unsaturated polyamides, unsaturated polyurethanes, acrylic-modified phenolic resins, and oligomers of acrylated amine compounds. Such oligomers are commercially available, for example, the "CN" and "SR" series from Sartomer Corporation, the "Aronix M-6000" series, the "7000" series, the "8000" series, the "Aronix M-1100", the "Aronix M-1200", and the "Aronix M-1600" series from Toagosei Co., Ltd., the "NK Ester" and "NK Oligo" from Shin-Nakamura Chemical Co., Ltd., the "Light Acrylate", "Light Ester", "Epoxy Ester", "Urethane Acrylate", and "High Performance Oligomer" series from Kyoeisha Chemical Co., Ltd., the "Special Acrylic Monomer" series from Osaka Organic Chemical Industry Co., Ltd., the "Acryester" and "Diabeam Oligomer" series from Mitsubishi Rayon Co., Ltd., the "Kayarad" and "Kayamer" series from Nippon Kayaku Co., Ltd., and the "Special Acrylic Monomer" series from Nippon Shokubai Co., Ltd. They are available under trade names such as the "(meth)acrylic acid / methacrylic acid ester monomer" series, Nippon Synthetic Chemical Industry Co., Ltd.'s "NICHIGO-UV Purple Urethane Acrylate Ligomer" series, Shin-Etsu Vinyl Acetate Co., Ltd.'s "Carboxylic Acid Vinyl Ester Monomer" series, Kohjinsha's "Functional Monomer" series, Daicel Allnex's "EBECRYL", "ACA", "KRM", "IRR", "RDX", and "OTA" series, BASF's "Laromer" series, Cognis' "Photomer" series, Negami Chemical Industries, Ltd.'s "Art Resin" series, NOF Chemical Co., Ltd.'s "Blenmer" series, Daiichi Kogyo Seiyaku Co., Ltd.'s "New Frontier" series, MIWON's "Miramer" series, and DSM's "AgiSyn" series.

[0013] In consideration of the environment, it is also possible to use polyurethane oligomers and / or polyurethane polyurea oligomers made from polyester polyols obtained from plant-derived dicarboxylic acid components or diol components. As the vegetable oil-modified polyfunctional polyester acrylate oligomer, any vegetable oil-modified polyester acrylate oligomer having 2 to 6 acrylate groups in the molecule can be used without any restrictions. Among these, for example, using one or more selected from the group consisting of EBECRYL 450, 452, 820, 1622 and tall oil fatty acid modified hexafunctional polyester acrylate (for example, AgiSyn 716) is preferred because it increases the biomass content of the electron beam curable printing ink composition. These oligomers can be used alone or in combination of two or more.

[0014] (polymer) The polymer as a curable resin having an ethylenically unsaturated bond is a component that increases in molecular weight together with the above-mentioned monomers and oligomers. Since it has a large molecular weight even before irradiation with active energy rays, it is a component that is useful for improving the viscoelasticity of the ink composition. Such a polymer is used, for example, in a state dissolved or dispersed in a monomer, which is a low-viscosity liquid. Examples of polymers having an ethylenically unsaturated bond include polydiallyl phthalate, acrylic resins having unreacted unsaturated groups, and acrylic-modified phenolic resins. Among these, polydiallyl phthalate is preferably used because of its particularly excellent compatibility with the above-mentioned monomers and oligomers. The content of the polymer having an ethylenically unsaturated bond relative to the total curable components is preferably 0 to 50.0% by mass, more preferably 0 to 30.0% by mass, and even more preferably 0 to 20.0% by mass. When printing using a plate, the polymer content within the above range is preferred because it can impart appropriate viscoelasticity to the ink composition to suppress the occurrence of misting and the like, and also ensure good curability of the ink composition.

[0015] The total content of one or more compounds selected from oligomers and polymers having unsaturated bonds in the solid content of the electron beam-curable printing ink composition is preferably 60.0% by mass or more, more preferably 70.0% by mass or more, and even more preferably 75% by mass or more. Similarly, the total content of the one or more compounds selected from oligomers and polymers having unsaturated bonds in the solid content is preferably 90.0% by mass or less, more preferably 85% by mass or less, and even more preferably 82% by mass or less. If the content is less than 60.0% by mass, the curability of the curable printing ink composition as a whole may be impaired, while if it exceeds 90.0% by mass, the ink composition may be poor in handleability, printability, and coatability.

[0016] (Compounds represented by general formula (1) and general formula (2)) In addition to the monomers described below, the ink composition of the present invention contains a compound represented by general formula (1), which is an alkylene oxide modified product of trimethylolpropane triacrylate, and / or a compound represented by general formula (2), which is a propylene oxide modified product of glycerin triacrylate. JPEG0007785466000003.jpg73132 General formula (1) Each R is independently -CH2-CH2-O- or -CH2-CH(CH3)-O- l+m+n=3~21 Among the compounds of general formula (1), preferred are trimethylolpropane triacrylates (TMPTA; trifunctional) modified with 3 to 21 units of ethylene oxide per molecule, such as EO-modified trimethylolpropane triacrylates (TMP(EO)3TA, TMP(EO)6TA, TMP(EO)9TA, TMP(EO)12TA, TMP(EO)15TA, TMP(EO)18TA, TMP(EO)21TA, etc.). In addition, all R's in general formula (1) may be the same or different. JPEG0007785466000004.jpg106158 General formula (2) R is -CH2-CH(CH3)-O- l+m+n=3~21 Among the compounds of general formula (2), for example, 3PO-modified glycerin triacrylate, 6PO-modified glycerin triacrylate, 9PO-modified glycerin triacrylate, 12PO-modified glycerin triacrylate, 15PO-modified glycerin triacrylate, and the like are preferred. The curable component of the ink composition of the present invention may contain a trifunctional monomer other than those of the general formula (1) and general formula (2) above, as long as the effect of the present invention is not impaired. The total content of the compounds represented by general formula (1) and / or general formula (2) in the electron beam-curable printing ink composition of the present invention is 1.0 to 80.0% by mass. It is preferably 5.0% by mass or more, more preferably 10.0% by mass or more, even more preferably 20.0% by mass or more, and most preferably 30.0% by mass or more. It is also preferably 70.0% by mass or less, more preferably 60.0% by mass or less, even more preferably 50.0% by mass or less, and most preferably 40.0% by mass or less. Alternatively, the total content of the compounds represented by general formula (1) and / or general formula (2) relative to the total curable components in the electron beam-curable printing ink composition of the present invention is preferably 5.0 mass% or more, more preferably 10.0 mass% or more, even more preferably 20.0 mass% or more, and most preferably 30.0 mass% or more, and is preferably 80.0 mass% or less, more preferably 70.0 mass% or less, even more preferably 60.0 mass% or less, and most preferably 55.0 mass% or less.

[0017] (monomer) Monomers are components that have ethylenically unsaturated bonds and polymerize as curable components to form high molecular weights, but before polymerization they are often liquid components with relatively low molecular weights. Monomers are also used as solvents when dissolving separately formulated resin components to make varnish, and to adjust the viscosity of ink compositions. Such monomers include monofunctional monomers having one ethylenically unsaturated bond in the molecule and difunctional or higher monomers having two or more ethylenically unsaturated bonds in the molecule. Difunctional or higher monomers can crosslink molecules when the ink composition cures, which contributes to accelerating the curing rate and forming a strong film. Monofunctional monomers do not have the crosslinking ability described above, but they contribute to reducing cure shrinkage associated with crosslinking. Various combinations of these monomers can be used as needed. The total content of the monomer and the compound of general formula (1) and / or general formula (2) among the curable components is preferably 25.0% by mass or more, more preferably 30.0% by mass or more, and even more preferably 33.0% by mass or more. It is also preferably 85.0% by mass or less, and more preferably 60% by mass or less. If it is less than 25.0% by mass, the curability of the ink composition may be reduced, and if it exceeds 85.0% by mass, the handleability of the ink composition may be reduced. The following monofunctional or higher functional monomers can be used alone or in combination of two or more. In this specification, "(meth)acrylate" means "acrylate and / or methacrylate", and "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid".

[0018] Examples of monofunctional monomers that can be used include unsaturated carboxylic acid compounds, alkyl (meth)acrylate compounds, hydroxyl group-containing (meth)acrylate compounds, halogen-containing (meth)acrylate compounds, ether group-containing (meth)acrylate compounds, carboxyl group-containing (meth)acrylate compounds, vinyl ether group-containing (meth)acrylate compounds, other (meth)acrylate compounds, styrene compounds, N-vinyl compounds, arylate compounds, and other compounds having one ethylenically unsaturated bond. The content of the monofunctional monomer in the curable component is preferably 20.0% by mass or less, more preferably 10.0% by mass or less, and even more preferably 5.0% by mass or less, or the curable component may not contain any monofunctional monomer.

[0019] -Unsaturated carboxylic acid compounds- Examples of unsaturated carboxylic acid compounds include unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, crotonic acid, isocrotonic acid, fumaric acid, and maleic acid, as well as salts and acid anhydrides thereof.

[0020] -Alkyl (meth)acrylate compounds- Examples of alkyl(meth)acrylates include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate, n-butyl(meth)acrylate, i-butyl(meth)acrylate, t-butyl acrylate, amyl(meth)acrylate, isoamyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate, decyl(meth)acrylate, dodecyl(meth)acrylate, isooctyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate, isostearyl(meth)acrylate, and isodecyl(meth)acrylate. acrylate, isomyristyl (meth)acrylate, octadecyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tridecyl (meth)acrylate, nonyl (meth)acrylate, hexadecyl (meth)acrylate, myristyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, 1-adamantyl (meth)acrylate, 3,5,5-trimethylcyclohexyl acrylate, 4-t-butylcyclohexyl (meth)acrylate, benzyl (meth)acrylate, and the like.

[0021] -Hydroxyl group-containing (meth)acrylate compounds- Examples of the hydroxyl group-containing (meth)acrylate compounds include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, 2-hydroxy-3-methoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and (poly)alkylene glycol-modified (meth)acrylates such as ethylene glycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, glycerin mono(meth)acrylate, 2-hydroxy-3-chloropropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-allyloxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, 2-ethylhexyl EO-modified (meth)acrylate, o-phenylphenol EO-modified acrylate, p-cumylphenol EO-modified (meth)acrylate, and nonylphenol EO-modified (meth)acrylate.

[0022] -Halogen-containing (meth)acrylate compounds- Examples of halogen-containing (meth)acrylate compounds include trifluoromethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H-hexafluoroisopropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,2H,2H-heptadecafluorodecyl (meth)acrylate, 2,6-dibromo-4-butylphenyl (meth)acrylate, 2,4,6-tribromophenoxyethyl (meth)acrylate, and 2,4,6-tribromophenol 3EO (ethylene oxide) adduct (meth)acrylate.

[0023] -Ether group-containing (meth)acrylate compounds- Examples of the ether group-containing (meth)acrylate compounds include 1,3-butylene glycol methyl ether (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxytripropylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, ethyl carbitol (meth)acrylate, 2-ethylhexyl carbitol (meth)acrylate, tetrahydrofuran (meth)acrylate, methyl methyl ether ... Furyl (meth)acrylate, cresyl polyethylene glycol (meth)acrylate, 2-(vinyloxyethoxy)ethyl (meth)acrylate, phenoxyethyl (meth)acrylate, p-nonylphenoxyethyl (meth)acrylate, p-nonylphenoxypolyethylene glycol (meth)acrylate, glycidyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, hexaethylene glycol monophenyl ether mono(meth)acrylate , diethylene glycol monobutyl ether acrylate, dipropylene glycol monomethyl ether (meth)acrylate, 3-methoxybutyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxypropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate (EO repeating unit number 400, 700, etc.), 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxy Butyl acrylate, ethoxyethyl acrylate, ethoxyethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, alkoxylated 2-phenoxyethyl (meth)acrylate (ethoxylated 2-phenoxyethyl (meth)acrylate, propoxylated 2-phenoxyethyl (meth)acrylate, etc.), alkoxylated nonylphenyl (meth)acrylate (ethoxylated (4) nonylphenol acrylate, etc.), 2-phenoxyethyl (meth)acrylate, paracumylphenoxyethylene glycol (meth)acrylate,Examples of the alkoxy and / or phenoxy (meth)acrylates include methylphenoxyethyl acrylate, ethoxylated succinic acid (meth)acrylate, ethoxylated tribromophenyl acrylate, and ethoxylated nonylphenyl (meth)acrylate.

[0024] -Carboxyl group-containing (meth)acrylate compounds- Examples of carboxyl group-containing (meth)acrylate compounds include β-carboxyethyl (meth)acrylate, succinic acid monoacryloyloxyethyl ester, ω-carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acryloyloxyethyl hydrogen phthalate, 2-(meth)acryloyloxypropyl hydrogen phthalate, 2-(meth)acryloyloxypropyl hexahydrohydrogen phthalate, and 2-(meth)acryloyloxypropyl tetrahydrohydrogen phthalate.

[0025] -Vinyl ether group-containing (meth)acrylate compounds- Examples of vinyl ether group-containing (meth)acrylate compounds include 2-vinyloxyethyl (meth)acrylate, 3-vinyloxypropyl (meth)acrylate, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, 1-methyl-3-vinyloxypropyl (meth)acrylate, 1-vinyloxymethylpropyl (meth)acrylate, and 2-methyl-3-vinyloxypropyl (meth)acrylate. Pyr, (meth)acrylate-3-methyl-3-vinyloxypropyl, (meth)acrylate-1,1-dimethyl-2-vinyloxyethyl, (meth)acrylate-3-vinyloxybutyl, (meth)acrylate-1-methyl-2-vinyloxypropyl, (meth)acrylate-2-vinyloxybutyl, (meth)acrylate-4-vinyloxycyclohexyl, (meth)acrylate-5-vinyloxypentyl, (meth)acrylate-6-vinyloxyhexyl, (meth)acrylate-4-vinyloxymethylcyclohexyl xylmethyl, (meth)acrylate-3-vinyloxymethylcyclohexylmethyl, (meth)acrylate-2-vinyloxymethylcyclohexylmethyl, (meth)acrylate-p-vinyloxymethylphenylmethyl, (meth)acrylate-m-vinyloxymethylphenylmethyl, (meth)acrylate-o-vinyloxymethylphenylmethyl, (meth)acrylate-2-(vinyloxyisopropoxy)ethyl, (meth)acrylate-2-(vinyloxyethoxy)propyl, (meth)acrylate-2-( (vinyloxyethoxy)isopropyl, (meth)acrylate-2-(vinyloxyisopropoxy)propyl, (meth)acrylate-2-(vinyloxyisopropoxy)isopropyl, (meth)acrylate-2-(vinyloxyethoxyethoxy)ethyl, (meth)acrylate-2-(vinyloxyethoxyisopropoxy)ethyl, (meth)acrylate-2-(vinyloxyisopropoxyethoxy)ethyl, (meth)acrylate-2-(vinyloxyisopropoxyisopropoxy)ethyl, (meth)acrylate-2-(vinyloxyisopropoxyisopropoxy)ethyl.

[0026] -Other (meth)acrylate compounds- Other (meth)acrylate compounds include, for example, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, acryloylmorpholine, morpholinoethyl (meth)acrylate, trimethylsiloxyethyl (meth)acrylate, diphenyl-2-(meth)acryloyloxyethyl phosphate, 2-(meth)acryloyloxyethyl acid phosphate, and caprolactone-modified 2-(meth)acryloyloxyethyl acid. Dophosphate, 2-hydroxy-1-(meth)acryloxy-3-methacryloxypropane, acryloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, 2-(meth)acryloyloxypropyl phthalate, tricyclodecane monomethylol (meth)acrylate, (meth)acrylic acid dimer, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalic acid Acid, 2-ethylhexyl-diglycol (meth)acrylate, aminoethyl (meth)acrylate, ethyl carbitol acrylate, ethyl diglycol acrylate, dimethylaminoethyl acrylate benzyl chloride quaternary salt, tribromophenyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, cresol (meth)acrylate, trimethylolpropane formal (meth)acrylate, neopentyl glycol (meth)acrylate benzoin acid esters, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 1-(meth)acryloylpiperidin-2-one, 2-(meth)acrylic acid-1,4-dioxaspiro[4,5]dec-2-ylmethyl, N-(meth)acryloyloxyethylhexahydrophthalimide, γ-butyrolactone (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, imide acrylate, vinyl (meth)acrylate, maleimide, and the like.

[0027] -Styrene-based compounds- Examples of styrene compounds include styrene, vinyltoluene, p-hydroxystyrene, p-chlorostyrene, p-bromostyrene, p-methylstyrene, p-methoxystyrene, pt-butoxystyrene, pt-butoxycarbonylstyrene, pt-butoxycarbonyloxystyrene, 2,4-diphenyl-4-methyl-1-pentene, and divinylbenzene.

[0028] -N-vinyl compounds- Examples of N-vinyl compounds include N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, N-vinyl-2-caprolactam, N-vinylcarbazole, and vinylmethyloxazolidinone.

[0029] -Arylate compounds- Examples of the arylate compounds include allyl glycidyl ether, diallyl phthalate, triallyl trimellitate, and isocyanuric acid triallylate.

[0030] -Other compounds with one ethylenically unsaturated bond- As the compound having one ethylenically unsaturated bond, "other compounds having one ethylenically unsaturated bond" other than the above compounds can be used. Examples of such compounds include vinyl acetate, vinyl monochloroacetate, vinyl benzoate, vinyl pivalate, vinyl butyrate, vinyl laurate, divinyl adipate, vinyl crotonate, vinyl 2-ethylhexanoate, three-membered ring compounds (e.g., vinylcyclopropanes, 1-phenyl-2-vinylcyclopropanes, 2-phenyl-3-vinyloxiranes, 2,3-divinyloxiranes, etc.), and cyclic ketene acetals (e.g., 2-methylene-1,3-dioxepane, podoxolanes, 2-methylene-4-phenyl-1,3-dioxepane, 4,7-dimethyl-2-methylene-1,3-dioxepane, 5,6-benzo-2-methylene-1,3-dioxepane, etc.).

[0031] As the difunctional or higher functional monomer (a compound having two or more ethylenically unsaturated bonds), for example, the following known compounds having two or more ethylenically unsaturated bonds can be used. Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, pentyl glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hydro Hydroxypivalyl hydroxypivalate di(meth)acrylate, hydroxypivalyl hydroxypivalate dicaprolactonate di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,2-hexanediol di(meth)acrylate, 1,5-hexanediol di(meth)acrylate, 2,5-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,2-octanediol di(meth)acrylate, 1,9-nonanediol Di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,2-dodecanediol di(meth)acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,2-tetradecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,2-hexadecanediol di(meth)acrylate, 2-methyl-2,4-pentane Tandiol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-dimethyl-2,4-pentanediol di(meth)acrylate, 2,2-diethyl-1,3-propanediol di(meth)acrylate, 2,2,4-trimethyl-1,3-pentanediol di(meth)acrylate, dimethylol octane di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-Hexanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate, 1,2-hexanediol di(meth)acrylate, 1,5-hexanediol di(meth)acrylate, 2,5-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate Acrylate, 1,8-octanediol di(meth)acrylate, 1,2-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,2-dodecanediol di(meth)acrylate, 1,14-tetradecanediol Dimethyl-2,4-pentanediol di(meth)acrylate, 1,2-tetradecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,2-hexadecanediol di(meth)acrylate, 2-methyl-2,4-pentanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-dimethyl-2,4-pentanediol di(meth)acrylate ter)acrylate, 2,2-diethyl-1,3-propanediol di(meth)acrylate, 2,2,4-trimethyl-1,3-pentanediol di(meth)acrylate, dimethylol octane di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2,4-diethyl-1,5-Pentanediol di(meth)acrylate, tricyclodecanedimethylol di(meth)acrylate, tricyclodecanedimethylol dicaprolactonate di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, bisphenol A tetraethylene oxide adduct di(meth)acrylate, bisphenol F tetraethylene oxide adduct di(meth)acrylate, bisphenol S tetraethylene oxide adduct di(meth)acrylate, hydrogenated bisphenol A tetraethylene oxide adduct di( Bifunctional monomers such as di(meth)acrylates of polyhydric alcohols such as glycerin, pentaerythritol, diglycerin, ditrimethylolpropane, and dipentaerythritol; hydrogenated bisphenol F tetraethylene oxide adduct di(meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, hydrogenated bisphenol F di(meth)acrylate, bisphenol A tetraethylene oxide adduct dicaprolactonate di(meth)acrylate, bisphenol F tetraethylene oxide adduct dicaprolactonate di(meth)acrylate, etc.;

[0032] trifunctional monomers such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane tricaprolactonate tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolhexane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, and pentaerythritol tri(meth)acrylate; Trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tetracaprolactonate tetra(meth)acrylate, diglycerin tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ditrimethylolpropane tetracaprolactonate tetra(meth)acrylate, ditrimethylolethane tetra(meth)acrylate, ditrimethylolbutane tetra(meth)acrylate, ditrimethylolhexa Examples of suitable monomers include tetrafunctional or higher functional monomers such as tetramethylolpropane tetra(meth)acrylate, ditrimethylol octane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, and tripentaerythritol polyalkylene oxide hepta(meth)acrylate. Among these, preferred examples include trimethylolpropane triacrylate (TMPTA; trifunctional), ditrimethylolpropane tetraacrylate (DITMPTA; tetrafunctional), dipentaerythritol hexaacrylate (DPHA; hexafunctional), and hexanediol diacrylate (HDDA; bifunctional).

[0033] [Dimethylpolysiloxane] The dimethylpolysiloxane used in the present invention is unmodified, is extremely chemically stable, and has the property of being oxidized at high temperatures. Unmodified dimethylpolysiloxane has a structure formed by polymerizing units consisting of dimethylsiloxane. Such unmodified dimethylpolysiloxane has a structure represented by the following formula: The molecular weight varies depending on the value of n in the following general formula (3), but any structure without functional groups can be used in the present invention regardless of the value of n. Alternatively, it may be a straight chain as shown in the following formula, in which n in the following formula is preferably 3 to 30, and more preferably 4 to 20. Furthermore, cyclic dimethylpolysiloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane may also be used. The content of dimethylpolysiloxane in the ink composition of the present invention is 0.01 to 10.0% by mass, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and preferably 5.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less. If the content is less than 0.01% by mass, the scratch resistance is insufficient both before and after the retort test, and the heat resistance is also insufficient. If the content exceeds 10.0 mass%, dimethylpolysiloxane may separate and be present in the printed ink composition, and this dimethylpolysiloxane on the surface may not contribute to the curing of the ink composition. Furthermore, the separated dimethylsiloxane may peel off from the coating surface before or after curing, or may stain other items that come into contact with it. JPEG0007785466000005.jpg38170 General formula (3) Modified polysiloxanes other than the above-mentioned unmodified dimethylpolysiloxane and having a structure substituted with hydroxyl groups, amino groups, (poly)ether groups, epoxy groups, carboxy groups, carbinol groups, mercapto groups, phenol groups, ester groups, alkoxy groups, halogen atoms, aralkyl groups, aralkyl groups, long-chain alkyl groups, higher fatty acid ester-modified, higher aliphatic amide groups, etc., do not have the ability to be cured together with polymerizable monomers, etc., when irradiated with an electron beam, unlike the unmodified dimethylpolysiloxane of the present invention. However, these modified polysiloxanes can be added to the extent that the effects of the present invention are not impaired.

[0034] [Photopolymerization initiator] The photopolymerization initiator is a component that generates radicals when irradiated with active energy rays, and the generated radicals polymerize the compound having the ethylenically unsaturated bond, thereby curing the ink composition. The ink composition of the present invention polymerizes and cures when irradiated with an electron beam, even if it does not contain a photopolymerization initiator. However, when a photopolymerization initiator is contained, it is not particularly limited as long as it generates radicals when irradiated with an electron beam, for example, the following. One or more compounds selected from the group consisting of acylphosphine oxide compounds, triazine compounds, aromatic ketone compounds, aromatic onium salt compounds, organic peroxides, thioxanthone compounds, thiophenyl compounds, anthracene compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, halogenated hydrocarbon compounds and alkylamine compounds, iodonium salt compounds and sulfonium salt compounds can be used.

[0035] Specifically, examples of the photopolymerization initiator include benzophenone, diethylthioxanthone, 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropan-1-one, 4-benzoyl-4'-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, and bis-2,6-dimethoxybenzoyl. Examples of such photopolymerization initiators include 2,4,4-trimethylpentylphosphine oxide, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, and 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butan-1-one. These photopolymerization initiators are commercially available, for example, from IGM Resins BV under the trade names Omnirad 907, Omnirad 369, Omnirad 184, Omnirad 379, Omnirad 819, and Omnirad TPO, and from Lamberti under the trade name DETX. These photopolymerization initiators can be used alone or in combination of two or more.

[0036] When a photopolymerization initiator is contained in the ink composition, its content must be within a range that does not impair the effects achieved by adding dimethylpolysiloxane. Furthermore, it is preferable not to contain a photopolymerization initiator to an extent that it affects the curability of the electron beam-curable printing ink composition of the present invention, and it is also possible not to contain it at all.

[0037] [Pigment] The ink composition of the present invention contains a pigment. The pigment is a component added to the ink composition to impart coloring power, hiding power, etc., and examples thereof include color pigments, white pigments, metal powders, etc. Examples of such pigments include, without particular limitation, the following organic and / or inorganic pigments that have conventionally been used in ink compositions:

[0038] Examples of pigments include dye lake pigments, azo-based, benzimidazolone-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigo-based, thioindigo-based, perylene-based, perinone-based, diketopyrrolopyrrole-based, isoindolinone-based, nitro-based, nitroso-based, flavanthrone-based, quinophthalone-based, pyranthrone-based, and indanthrone-based pigments, as well as various inorganic pigments. Among these pigments, examples include yellow pigments such as disazo yellow (pigment yellow 12, pigment yellow 13, pigment yellow 14, pigment yellow 17, pigment yellow 1) and Hansa yellow; magenta pigments such as brilliant carmine 6B, lake red C, and watching red; cyan pigments such as phthalocyanine blue, phthalocyanine green, and alkali blue; colored pigments (including achromatic colored pigments such as white and black) such as titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, iron black, chromium oxide green, carbon black, and graphite; and metal powders such as aluminum paste and bronze powder.

[0039] The content of the pigment is, for example, about 8 to 30 mass % of the total ink composition depending on the desired degree of coloring, but is not particularly limited. When preparing a colored ink composition, it is also possible to use a pigment or dye of another color in combination as a complementary color, or to add an ink composition of another color.

[0040] (Pigment dispersants and pigment dispersion resins) When the electron beam-curable printing ink composition of the present invention employs a pigment as the colorant, a pigment dispersant and / or a pigment dispersing resin may be blended therein. As the pigment dispersant, one or more types selected from the group consisting of known nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants can be used. The surfactant may be, for example, one or more selected from the group consisting of silicone surfactants (e.g., polyether-modified silicone oil, polyester-modified polydimethylsiloxane, polyester-modified methylalkylpolysiloxane, etc.), fluorine-based surfactants, oxyalkylene ether-based surfactants, acetylene glycol-based surfactants, phosphorus-based surfactants, sulfonic acid-based surfactants, etc. Furthermore, as the pigment dispersing resin, one or more types selected from the group consisting of polymer dispersants (for example, carbodiimide-based, polyester-based, polyamine-based, polyesteramine-based, polyurethane-based, fatty acid amine-based dispersants, polyacrylate-based, polycaprolactone-based, polysiloxane-based, multi-chain polymer nonionic, polymer ionic dispersants, etc.) can be used. When the electron beam curable printing ink composition of the present invention contains a pigment dispersant or a pigment dispersing resin, it is preferable that the content be 1 to 200 mass % when the total amount of pigments used is taken as 100 mass %.

[0041] [Other ingredients] In addition to the above-described components, other components may be added to the electron beam-curable printing ink composition of the present invention as needed, but they are not required to be added. Furthermore, components required for the printing method and application method may also be added. Examples of such components include extender pigments, non-curable resin components, polymerization inhibitors, salts such as phosphates, PTFE, waxes such as polyethylene wax, olefin wax, and Fischer-Tropsch wax, antifoaming agents, alcohols, and oil components such as vegetable oils and mineral oils.

[0042] The extender pigment is a component that imparts suitable printability, viscoelasticity, and other properties to the ink composition, and various types of extender pigments commonly used in preparing ink compositions can be used. Examples of such extender pigments include clay, kaolinite (kaolin), barium sulfate, magnesium sulfate, calcium carbonate, silicon oxide (silica), bentonite, talc, mica, and titanium oxide. The amount of such extender pigment added is, for example, about 0 to 33% by mass of the total ink composition, but is not particularly limited.

[0043] The non-curable resin component is a component that contributes to imparting suitable properties such as printability and viscoelasticity to the electron beam-curable printing ink composition of the present invention, and does not have an unsaturated bond that contributes to polymerization. Examples of such a resin component include various resins that have traditionally been used in printing ink compositions. Preferably, the binder is compatible with the above-mentioned monomers and oligomers, and one or more selected from the group consisting of styrene-acrylic resins, acrylic resins, styrene-maleic acid resins, polyester resins, alkyd resins, rosin-modified phenolic resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, rosin-modified petroleum resins, rosin ester resins, phenolic resins, rosin resins, block polymers, graft polymers (core-shell polymers), acrylic-modified phenolic resins, petroleum resin-modified phenolic resins, vegetable oil-modified alkyd resins, fatty acid-modified rosin resins, petroleum resin-modified phenolic resins, terpene phenolic resins, petroleum resins, hydrocarbon resins (such as polybutene and polybutadiene), fluororesins (such as tetrafluoroethylene (PTFE) resin wax), etc. Particularly preferably, one or more selected from the group consisting of styrene-acrylic resins, alkyd resins, rosin-modified phenolic resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, rosin ester resins, fatty acid-modified rosin resins, vegetable oil-modified alkyd resins, and terpene phenolic resins can be used. Among these, rosin-modified maleic acid resin and terpene phenol resin are preferred from the viewpoint of adhesiveness. Such a resin preferably has a weight average molecular weight of 500 to 300,000. From the viewpoint of quick drying when irradiated with active energy rays, the acid value is preferably 1 to 100 mgKOH / g.

[0044] The styrene-acrylic resin is a copolymer of styrene and an acrylic acid ester, and various commercially available products can be used. When using a styrene-acrylic resin, it is convenient to dissolve the solid styrene-acrylic resin in the above-mentioned monomer to form a varnish, which is then added during the preparation of the ink composition. In this case, the content of the styrene-acrylic resin in the varnish may be appropriately determined taking into consideration handleability and the like, and can be, for example, about 5 to 50 mass %.

[0045] The content of the non-curable resin in the solids of the electron beam-curable printing ink composition is preferably 80.0% by mass or less, more preferably 60.0% by mass or less, and even more preferably 50.0% by mass or less. It is also preferably 30.0% by mass or more, and even more preferably 40.0% by mass or more. A content of 30.0 to 80.0% by mass is preferred because it imparts appropriate viscoelasticity to the ink composition and suppresses the occurrence of misting without impairing its excellent curability with electron beams. In the electron beam-curable printing ink composition of the present invention, the use of a fatty acid-modified rosin resin or a rosin-modified alkyd resin as the non-curable resin can improve properties such as the biomass content.

[0046] The electron beam-curable printing ink composition may contain a known polymerization inhibitor to prevent polymerization during storage. Preferred examples of polymerization inhibitors include phenolic compounds such as butylhydroxytoluene, tocopherol acetate, nitrosamines, benzotriazole, and hindered amines, with butylhydroxytoluene being particularly preferred. Addition of such a polymerization inhibitor can prevent the ink composition from thickening due to the polymerization reaction during storage. The content of the polymerization inhibitor in the ink composition is, for example, approximately 0.1 to 1.0% by mass. However, when the electron beam curable printing ink composition does not contain a conventional polymerization initiator, it is possible to not contain a polymerization inhibitor.

[0047] (wax) The wax to be used may be any wax that has an average particle size of 8.0 μm or less and that has been conventionally used in printing inks in order to improve scratch resistance. Specifically, usable waxes include animal and vegetable waxes such as beeswax, lanolin wax, spermaceti, candelilla wax, carnauba wax, rice wax, Japan wax, and jojoba oil; mineral waxes such as montan wax, ozogelite, ceresin, paraffin wax, microcrystalline wax, and petrolatum; petroleum waxes; synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene wax, oxidized polyethylene wax, and oxidized polypropylene wax; modified waxes such as montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives; hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives; and polytetrafluoroethylene wax, all of which have an average particle size of 8.0 μm or less, preferably 6.0 μm or less, more preferably 4.0 μm or less, and most preferably 1.0 to 2.0 μm from the viewpoint of scratch resistance. Among these, polytetrafluoroethylene wax and polyethylene wax are preferable in terms of friction properties. The average particle size of the wax used is appropriately selected depending on the viscosity of the electron beam curable printing ink composition.

[0048] The ink composition of the present invention does not need to contain wax. If wax is contained, the content of wax in the electron beam curable printing ink composition is preferably in the range of 5.0 mass % or less. If the wax content is more than 5.0% by mass, the ink transferability tends to decrease.

[0049] (solvent) The electron beam curable printing ink composition may contain a known solvent in order to lower the viscosity and improve the wetting and spreading properties on the substrate. Examples of the solvent include water, glycol monoacetates, glycol diacetates, glycol ethers, lactate esters, etc. Among these, water, tetraethylene glycol dialkyl ether, ethylene glycol monobutyl ether acetate, and diethyl diglycol are preferred. When the electron beam curable printing ink composition contains a solvent, the content thereof can be set to 0 to 50.0 mass %.

[0050] (surface conditioner) The electron beam curable printing ink composition of the present invention may contain a known surface conditioner. As the surface conditioner, for example, one or more selected from the group consisting of silicon-based surface conditioners, fluorine-based surface conditioners, acrylic-based surface conditioners, acetylene glycol-based surface conditioners, and the like can be used. Specific examples of the surface conditioner that can be used include one or more selected from the group consisting of the BYK series from BYK Chemie, the TEGO series from Evonik Degussa Japan, and the Polyflow series from Kyoeisha Chemical. When the electron beam curable printing ink composition contains a surface conditioner, the content thereof can be set to 0.01 to 1.0 mass %.

[0051] [Manufacturing method] The method for producing the electron beam curable printing ink composition of the present invention is not particularly limited, and any known method can be used. For example, the composition can be prepared by adding all of the above-mentioned components and mixing them in a bead mill or a three-roll mill. Alternatively, a concentrated base may be prepared in advance by mixing a pigment, a pigment dispersant, and various electron beam curable compounds, and then additives such as an electron beam curable compound, a polymerization initiator, and, if necessary, a surfactant may be added to the concentrated base to obtain a desired composition.

[0052] Alternatively, the above components may be mixed and milled in a bead mill, a three-roll mill, or the like to disperse the pigments (i.e., color pigments and extender pigments), and then additives (polymerization initiators, polymerization inhibitors, waxes, and other additives, etc.) may be added as needed, and the viscosity may be adjusted by further adding other components. The viscosity of the electron beam-curable printing ink composition of the present invention is not limited and can be adjusted appropriately depending on the application, but is, for example, 2000 mPa·s or less, preferably 1500 mPa·s or less, and more preferably 400 to 1500 mPa·s.

[0053] The substrate onto which the electron beam curable printing ink composition of the present invention is printed and applied includes plastic, paper, carton, etc., and may also be a composite substrate such as a laminate composed of a plurality of these substrates.

[0054] Among these, examples of plastic substrates onto which the electron beam curable printing ink composition is printed or coated include polyester polymers (e.g., polyethylene terephthalate (PET), polyethylene naphthalate, etc.), cellulose polymers (e.g., diacetyl cellulose, triacetyl cellulose (TAC), etc.), polycarbonate polymers, polyacrylic polymers (e.g., polymethyl methacrylate, etc.), vinyl chloride polymers, polyolefin polymers (e.g., polyethylene, polypropylene, polyolefin polymers having a cyclic or norbornene structure, ethylene-propylene copolymer polymers, etc.), ... One or more polymers selected from the group consisting of polyamide polymers (e.g., nylon, aromatic polyamide polymers, etc.), polystyrene polymers (e.g., polystyrene, acrylonitrile-styrene copolymer polymers, etc.), polyimide polymers, polysulfone polymers, polyethersulfone polymers, polyetherketone polymers, polyphenylsulfide polymers, polyvinyl alcohol polymers, polyvinylidene chloride polymers, polyvinyl butyral polymers, polyarylate polymers, polyoxymethylene polymers, and polyepoxy polymers, as well as blends of these polymers, can be used.

[0055] (Printing and coating methods) When printing using the electron beam curable printing ink composition of the present invention, known printing methods and curing conditions for the electron beam curable ink composition can be used. [Example]

[0056] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass," and "parts" and "parts by mass" mean "parts by mass." The figures for the amounts of each material in the tables are also "parts by mass."

[0057] (Electron beam curable printing ink composition) The ingredients used in Table 1 below are as follows: PB15:3: LIONOL BLUE FG-7330 (Toyocolor) Polyester acrylate oligomer: CN704 (Sartomer) 6EO modified TMPTA (6EO modified trimethylolpropane triacrylate) 9EO modified TMPTA (9EO modified trimethylolpropane triacrylate) 15EO modified TMPTA (15EO modified trimethylolpropane triacrylate) 3PO modified TMPTA (3PO modified trimethylolpropane triacrylate) 3PO-modified GPTA (3PO-modified glycerin triacrylate) 9PO-modified GPTA (9PO-modified glycerin triacrylate) 15PO modified GPTA (15PO modified glycerin triacrylate) TMPTA (trimethylolpropane triacrylate) DTMPTA (ditrimethylolpropane tetraacrylate) DPHA (Dipentaerythritol hexaacrylate) PETA (Pentaerythritol tetraacrylate) Dimethyl silicone oil 1: TSF-451-5M (Momentive) Dimethyl silicone oil 2: TSF-451-15M (Momentive) Dimethyl silicone oil 3: TSF-451-30M (Momentive) Side chain epoxy modified dimethyl silicone oil: KF-1001 (Shin-Etsu Chemical Co., Ltd.) Side-chain alicyclic epoxy-modified dimethyl silicone oil: KF-102 (Shin-Etsu Chemical Co., Ltd.) Long-chain alkyl-modified dimethyl silicone oil: KF-4701 (Shin-Etsu Chemical Co., Ltd.) Side-chain higher fatty acid ester modified dimethyl silicone oil: X-22-715 (Shin-Etsu Chemical Co., Ltd.) Both ends acrylic-modified dimethyl silicone oil: X-22-2445 (Shin-Etsu Chemical Co., Ltd.)

[0058] (Preparation of Electron Beam-Curable Printing Ink Composition) The components were blended to obtain the blending compositions (mass %) shown in Table 1, and mixed by stirring to obtain electron beam curable printing ink compositions of Examples and Comparative Examples.

[0059] (How to create a coating) The ink compositions of the following examples and comparative examples were applied to one side of a 0.25 μm thick corona-treated L-LDPE film (linear low-density polyethylene, Mitsui Chemicals Tocello Co., Ltd.) using a φ0.2 mm bar coater.

[0060] (electron beam curing) The ink composition coated surface of the L-LDPE film obtained above was irradiated with electron beams. The acceleration voltage for generating the electron beam was 90 kV, 10 kGy, the processing speed was 30 m / min, and one pass.

[0061] (Adhesiveness) After the ink coating was cured by electron beam irradiation, Nichiban Cellotape (registered trademark) was applied to the coating and then peeled off. This was repeated five times at the same location on the coating for evaluation (before retorting). Furthermore, the ink film after UV curing treatment was immersed in hot water at 120°C for 30 minutes, and then Nichiban cellophane tape was applied to the ink film and then peeled off. This was repeated five times at the same location on the film for evaluation (after retort). ○: No peeling of ink film ×: Ink film peeling

[0062] (scratch resistance) The ink film after UV curing was rubbed with the back of a fingernail. This was repeated 10 times on the same spot on the film (before retorting). Furthermore, the ink film after UV curing was immersed in hot water at 120°C for 30 minutes, and then evaluated in the same way (after retorting). ○: No ink film peeling △: Some ink film has fallen off ×: Most of the ink film has fallen off

[0063] (Heat resistance) After the curing process, the ink film was pressed against a glossy aluminum surface using a thermal gradient tester HG-100 (Toyo Seiki Co., Ltd.) at -2 kg / cm² for 1 minute, and the critical temperature at which the ink film was removed when the aluminum foil was peeled off was measured. ○: Not removed even at temperatures above 200°C ×: Removed at temperatures below 200°C

[0064] [Table 1] JPEG0007785466000007.jpg196170

[0065] In Examples 1 to 9, the ink compositions according to the present invention were used, and the ink coatings were sufficiently cured. Furthermore, the inks exhibited excellent adhesion and scratch resistance before and after retorting, as well as excellent heat resistance after curing. These properties were excellent even without the inclusion of conventional photopolymerization initiators, etc. In contrast, Comparative Example 1, which did not contain dimethyl silicone oil (dimethyl polysiloxane), and Comparative Examples 2 to 6, which contained modified dimethyl silicone oil (dimethyl polysiloxane) instead of dimethyl silicone oil (dimethyl polysiloxane), showed poor scratch resistance and insufficient heat resistance before and after the retort test. Furthermore, Comparative Examples 7 to 10, which did not contain the compounds represented by general formulas (1) and (2), showed poor adhesion and heat resistance before and after the retort test, and in some cases showed insufficient scratch resistance before and after the retort test.

Claims

1. An electron beam-curable printing ink composition comprising a pigment, a curable resin containing a compound and an oligomer represented by general formula (1) and / or general formula (2), and dimethylpolysiloxane, and not containing a polymerization initiator, The composition contains a total of 20.0 to 80.0 mass% of the compound represented by the general formula (1) and / or the general formula (2) and 0.01 to 10.0 mass% of dimethylpolysiloxane, based on the entire composition; An electron beam curable printing ink composition comprising the oligomer in an amount of 30% by mass or more and 60% by mass or less relative to the curable resin. General formula (1): R is independently —CH—CH—O— or —CH—CH(CH)—O—, l+m+n=3 to 21 General formula (2): R is —CH2—CH(CH3)—O—, l+m+n=3 to 21

2. 2. The electron beam curable printing ink composition according to claim 1, wherein the oligomer comprises a polyester acrylate oligomer.

3. A printed matter obtained by printing with the electron beam curable printing ink composition according to claim 1 or 2.

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