Electron beam curable composition and laminate

Abstract

An electron-beam-curable composition comprising: a resin (A) having a weight-average molecular weight of 5,000-50,000; a (meth)acrylate compound (B) having a weight-average molecular weight of 700-3,000, wherein the weight-average molecular weight per (meth)acryloyl group is 100-300; and a pigment (C).

Description

Technical Field

[0001] Embodiments of the present invention relate to an electron beam curable composition and a laminate.

Background Art

[0002] In recent years, in the field of the printing industry, the use of curing technology by active energy rays has been expanding. According to the curing technology by active energy rays, it is possible to shorten the process time by instant drying, reduce the environmental load and improve the work safety by non-containing volatile components (Non-VOC), and realize strong coating film physical properties by crosslinking reaction.

[0003] The utilization of the curing technology by active energy rays has started from the commercial printing field based on paper substrates such as leaflets and posters, and has been developed into various fields by the development of printing technologies including printing machines and printing inks. Along with this, the application of the curing technology by active energy rays is also expanding to the fields using various film substrates. For example, it is being increasingly used as a packaging material for package products such as food, cosmetics, and toy packaging.

[0004] Especially when the packaging material is for food packaging applications, from the viewpoint of ensuring safety to health, it is indispensable to use an active energy ray curable composition capable of suppressing migration. Regarding migration in packaging materials for food packaging (hereinafter also referred to as food packaging materials), various regulations provided for ensuring the safety of food packaging are known. Among them, the Swiss Ordinance (Swiss Ordinance RS817.023.21 Annex10) provides a positive list (regulation of usable raw materials) for packaging materials including inks and varnishes not in contact with food, and further regulates the allowable migration amount (SML) for each raw material. Although the regulatory level in the Swiss Ordinance is very strict, that regulatory level has become an important indicator as a global standard for food packaging materials in recent years due to the increasing consumer safety orientation.

[0005] On the other hand, when a conventional active energy ray-curable composition is used for food packaging materials, it tends to be difficult to meet the above SML regulatory levels. Active energy ray-curable compositions are roughly classified into ultraviolet-curable compositions and electron beam-curable compositions from the viewpoint of reaction form. Among them, in ultraviolet-curable compositions, a photoinitiator is required, so migration problems are likely to occur due to low molecular weight photoinitiators. On the other hand, electron beam-curable compositions do not require a photoinitiator because they utilize high-energy electron beams. Therefore, from the viewpoint of improving migration problems, it is considered that electron beam-curable compositions can be preferably used in applications such as food packaging materials.

[0006] However, typical electron beam-curable compositions, like ultraviolet-curable compositions, contain (meth)acrylate monomers as the main component of the binder, and migration problems are likely to occur due to low molecular weight (meth)acrylate monomers. Therefore, even when an electron beam-curable composition is used as an ink, further studies are required to improve migration.

[0007] In addition, in order to meet the diversification and sophistication of recent consumer needs, the laminates that make up the packaging materials of packages are diversifying and becoming more complex. For this reason, an active energy ray-curable composition that has good adhesion to various substrate configurations and can form a strong film is desired.

[0008] However, in the development of active energy ray-curable compositions, in a design that emphasizes adhesion to various film substrates, the film strength is likely to deteriorate. On the other hand, in a design that emphasizes film strength, the adhesion to various film substrates is likely to deteriorate. Thus, there is a proposition that film strength and adhesion are likely to fall into a trade-off.

[0009] As a trouble related to this, in the packaging material of a package having a printed surface after printing with an active energy ray-curable ink, scratches may occur on the printed surface of the packaging material or the printed surface may peel off due to vibrations and friction generated during transportation by a truck or the like, which has become a major problem and the solution to this is desired.

[0010] In addition, due to recent health safety and environmental regulation compliance, the selection range of raw materials that can be used as materials for active energy ray-curable compositions has been narrowing. In particular, an active energy ray-curable composition that does not contain persistent organic pollutants typified by tetrafluoroethylene and a photoinitiator from the viewpoints of health and safety is desired.

[0011] On the other hand, in the printing of active energy ray-curable compositions, various printing methods such as lithography, flexography, and resin letterpress printing are used. Lithography includes lithography with water, which uses dampening water and forms an image by the repulsion between the oil (ink) in the image area and the water (dampening water) in the non-image area, and lithography without water, which uses a silicone layer in the non-image area and forms an image by the repulsion with the ink in the image area. Among them, lithography with water, which has good workability, is preferably used.

[0012] Recently, at printing sites, demands for shortening delivery times, reducing the number of personnel, labor saving, and high-speed printing have been increasing for the purpose of improving production efficiency and reducing costs. Therefore, a printing ink that can stably obtain high-quality printed matter at high speed without trouble over a long period of time is desired. In particular, it is difficult to ensure the viscoelasticity and emulsification performance required when an active energy ray-curable composition for a film substrate is made into a printing ink. Therefore, the problems are that the density becomes unstable during high-speed printing and that stains are likely to occur during printing, and the solution to this is desired.

[0013] Under such circumstances, inks and varnishes that are active energy ray-curable compositions have been studied.

[0014] For example, Patent Document 1 discloses a urethane resin using an alkyl monoalcohol compound, a polyol compound, and a polyisocyanate compound as essential reaction raw materials as a binder resin. However, in a composition obtained by combining the disclosed binder resin, a (meth)acrylate monomer, and a photopolymerization initiator, the adhesion to a film substrate tends to be insufficient.

[0015] Patent Document 2 discloses an electron beam curable composition containing a rosin-modified resin, a (meth)acrylate compound, and an extender pigment as essential components. Although the disclosed electron beam curable composition can be expected to improve printing suitability, its resistance to damage and peeling against vibration and friction during transportation was not sufficient.

[0016] Patent Document 3 discloses an electron beam curable composition containing an acrylate monomer, an acrylate oligomer, an inert resin, an acrylated epoxidized vegetable oil, and a white pigment as essential components. However, the disclosed electron beam curable composition is configured for primer applications. Therefore, especially when used in water-based lithographic printing, the emulsification balance with dampening water is poor, and since it is necessary to reduce the molecular weight of the binder resin, the viscoelasticity required for ink cannot be obtained, and it has been difficult to stably obtain high-quality printed matter over a long period of time.

[0017] Patent Document 4 discloses an active energy ray curable resin composition containing a urethane (meth)acrylate resin having a specific weight average molecular weight and a (meth)acrylate compound having two types of (meth)acryloyl groups with 1 to 2 functional groups and 3 or more functional groups as essential components. However, the disclosed active energy ray curable resin composition uses a low molecular weight (meth)acrylate compound as the (meth)acrylate compound other than the urethane (meth)acrylate resin. Therefore, when using the above composition as printing ink, there is a concern of deteriorating curability and migration during high-speed printing. Also, the stability during flight and the stability during emulsification tend to deteriorate during water-based lithographic printing.

Prior Art Documents

Patent Document

[0018]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0019] One embodiment of the present invention can be used as a packaging material for various packages, has safety such as low migration properties, and can form a film that can achieve both excellent adhesion to a film substrate and film strength, etc., thereby reducing troubles such as rubbing or peeling during transportation and having good printing suitability, and provides an electron beam curable composition. Another embodiment of the present invention provides a laminate using the electron beam curable composition of the above embodiment.

Means for Solving the Problems

[0020] As a result of intensive studies, the present inventors have found that the above problems can be solved by using the electron beam curable composition described below, and have completed the present invention. Embodiments of the present invention are described below. However, the present invention is not limited to the following embodiments and includes various embodiments.

[0021] <1> An electron beam curable composition comprising a resin (A) having a weight average molecular weight of 5,000 to 50,000, a (meth)acrylate compound (B) having a weight average molecular weight of 700 to 3,000 and a weight average molecular weight of 100 to 300 per (meth)acryloyl group, and a pigment (C).

[0022] <2>The ratio of the content (% by mass) of the (meth)acrylate compound (B) in the total mass of the composition to the content (% by mass) of the resin (A) in the total mass of the composition is 0.5 to 8.0, and the electron beam curable composition according to <1> above.

[0023] <3>The resin (A) contains at least one selected from the group consisting of a rosin-modified resin and a urethane (meth)acrylate resin, and the electron beam curable composition according to <1> or <2> above.

[0024] <4>The (meth)acrylate compound (B) contains an amine-modified (meth)acrylate, and the electron beam curable composition according to any one of <1> to <3> above.

[0025] <5>The (meth)acrylate compound (B) contains a polyester (meth)acrylate, and the electron beam curable composition according to any one of <1> to <4> above.

[0026] <6>The total content of the resin (A), the (meth)acrylate compound (B), and the pigment (C) is 60 to 90% by mass based on the total mass of the composition, and the electron beam curable composition according to any one of <1> to <5> above.

[0027] <7>The electron beam curable composition according to any one of <1> to <6> above, which substantially does not contain a photoinitiator.

[0028] <8>The electron beam curable composition according to any one of <1> to <7> above, which substantially does not contain an organic solvent.

[0029] <9>The electron beam curable composition according to any one of <1> to <8> above, which substantially does not contain polytetrafluoroethylene wax.

[0030] <9>A laminate having a cured product of the electron beam curable composition according to any one of <1> to <9> above on a substrate.

[0031] <10>The laminate according to <9> above, wherein the base material is a film or paper.

[0032] <11>A method for manufacturing the laminate, comprising: applying the electron beam curable composition according to any one of <1> to <9> above on a base material to form a coating film; and irradiating the coating film with an electron beam under conditions of an accelerating voltage of 40 to 120 kV and an irradiation dose of 10 to 60 kGy. The disclosure of the present application is related to the subject matter described in Japanese Patent Application No. 2023-111823 filed on July 7, 2023, and all the disclosure contents thereof are incorporated herein by reference.

Advantages of the Invention

[0033] According to an embodiment of the present invention, it is possible to provide an electron beam curable composition that has safety such as low migration properties and can be used as a packaging material for various packages, and can form a coating film that achieves both excellent adhesion to a film base material and film strength, etc., thereby reducing troubles such as rubbing or peeling during transportation and having good printability. Further, it is possible to provide a laminate using the electron beam curable composition of the above embodiment.

Modes for Carrying Out the Invention

[0034] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described below, and various modifications are possible without departing from the gist of the present invention.

[0035] In addition, the "conjugated double bond" described in this specification refers to a bond in which a plurality of double bonds are alternately connected with a single bond in between. However, the π-electron conjugated system contained in an aromatic compound is excluded from the conjugated double bond. Further, the numerical range indicated by "~" in this specification means a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively.

[0036] <Resin (A)> The resin (A) in the electron beam curable composition of the present embodiment is a resin having a weight average molecular weight of 5,000 to 50,000. If the weight average molecular weight is 5,000 to 50,000, the resin type is not particularly limited, and known resins can be used. However, a resin having good compatibility with a (meth) acrylate compound and being soluble is preferred. When the weight average molecular weight of the resin is adjusted to 5,000 or more, the ink viscoelasticity required when the electron beam curable composition is made into ink can be easily obtained, and the emulsifying performance required when used in water-based lithographic printing can be easily obtained. Further, when the weight average molecular weight is adjusted within 50,000, good adhesion to the film can be easily obtained. In one embodiment, the weight average molecular weight of the resin (A) is preferably 10,000 to 25,000.

[0037] The resin (A) only needs to have a weight average molecular weight within the above range, and may or may not contain a (meth) acryloyl group in the molecule.

[0038] Specific examples of the resin (A) include diallyl phthalate resin, rosin-modified resin, polyester resin, epoxy resin, urethane (meth) acrylate resin, polyester (meth) acrylate resin, styrene acrylic polymer resin, petroleum resin, allyl resin, etc. In one embodiment, the resin (A) may contain at least one selected from the group consisting of diallyl phthalate resin, rosin-modified resin, polyester resin, and urethane (meth) acrylate resin. In other embodiments, as the allyl resin, an allyl resin other than diallyl phthalate resin such as a non-phthalate type allyl resin can also be used. That is, in such an embodiment, the resin (A) may contain at least one selected from the group consisting of diallyl phthalate resin, rosin-modified resin, polyester resin, urethane (meth) acrylate resin, and non-phthalate type allyl resin.

[0039] In one embodiment, the resin (A) preferably contains at least one selected from the group consisting of a rosin-modified resin and a urethane (meth) acrylate resin from the viewpoints of printability, film strength, and adhesion.

[0040] <rosin-modified resin> In an embodiment of the present invention, the rosin-modified resin is a resin containing a rosin-derived skeleton in the resin skeleton.

[0041] In one embodiment, the rosin-modified resin preferably contains a reaction product of raw material components including rosins, polybasic acids, and polyols. In one embodiment, the weight average molecular weight of the rosin-modified resin may preferably be 5,000 to 50,000, more preferably 5,400 to 46,000, and still more preferably 15,000 to 30,000.

[0042] In an embodiment of the present invention, rosins refer to monobasic acids having a cyclic diterpene skeleton, and represent rosin acid, disproportionated rosin acid, hydrogenated rosin acid, or alkali metal salts of the above compounds. Specific examples of rosins include abietic acid having a conjugated double bond and its conjugated compounds, neoabietic acid, palustric acid, and levopimaric acid. Other specific examples include pimaric acid, isopimaric acid, sandaracopimaric acid, and dehydroabietic acid, which do not have a conjugated double bond. Examples of natural resins containing these rosins include gum rosin, wood rosin, and tall oil rosin.

[0043] Examples of polybasic acids include carboxylic acids having two or more carboxyl groups in one molecule and their anhydrides.

[0044] Examples of the polybasic acid include 1,2,3,6 - tetrahydrophthalic acid, 3 - methyl - 1,2,3,6 - tetrahydrophthalic acid, 4 - methyl - 1,2,3,6 - tetrahydrophthalic acid, 1,2 - cyclohexanedicarboxylic acid, 1,3 - cyclohexanedicarboxylic acid, 1,4 - cyclohexanedicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, sebacic acid, azelaic acid, alkenyl succinic acids such as dodecenyl succinic acid and pentadecenyl succinic acid, o - phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, crotonic acid, isocrotonic acid, and acid anhydrides thereof.

[0045] Examples of the polyol include compounds having two or more hydroxyl groups in one molecule, such as dihydric alcohols and trihydric or higher alcohols.

[0046] The dihydric alcohol may have a linear, branched, or cyclic structure. For example, as linear alkylene dihydric alcohols, 1,2 - ethanediol, 1,2 - propanediol, 1,3 - propanediol, 1,2 - butanediol, 1,4 - butanediol, 1,2 - pentanediol, 1,5 - pentanediol, 1,6 - hexanediol, 1,2 - hexanediol, 1,5 - hexanediol, 2,5 - hexanediol, 1,7 - heptanediol, 1,8 - octanediol, 1,2 - octanediol, 1,9 - nonanediol, 1,2 - decanediol, 1,10 - decanediol, 1,12 - dodecanediol, 1,2 - dodecanediol, 1,14 - tetradecanediol, 1,2 - tetradecanediol, 1,16 - hexadecanediol, 1,2 - hexadecanediol, etc. are included. Examples of the branched alkylene dihydric alcohol include 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-dimethylpentanediol, 2,2-diethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dimethylol octane, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, and the like. Examples of the cyclic alkylene dihydric alcohol include 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cycloheptanediol, tricyclodecane dimethanol, hydrogenated catechol, hydrogenated resorcinol, hydrogenated hydroquinone, and the like. Furthermore, polyether polyols such as polyethylene glycol (n = 2 to 20), polypropylene glycol (n = 2 to 20), polytetramethylene glycol (n = 2 to 20), and polyester polyols and the like can be mentioned.

[0047] Furthermore, examples of the trihydric or higher alcohol include glycerin, trimethylolpropane, pentaerythritol, 1,2,6-hexanetriol, 3-methylpentane-1,3,5-triol, hydroxymethylhexanediol, trimethylol octane, diglycerin, ditrimethylolpropane, dipentaerythritol, sorbitol, inositol, tripentaerythritol, and the like.

[0048] <Urethane (meth) acrylate resin> In an embodiment of the present invention, the urethane (meth) acrylate resin refers to a resin having a urethane bond and a (meth) acryloyl group obtained by reacting an isocyanate group and a hydroxy group.

[0049] In an embodiment of the present invention, the urethane (meth)acrylate resin can be produced according to a method well-known in the art. For example, in one embodiment, it may be a compound obtained by reacting a polyisocyanate, a (meth)acrylate having a hydroxyl group, and a polyol in a mixing ratio such that the isocyanate groups are in excess.

[0050] In one embodiment, from the viewpoint of easily improving the physical properties of the coating film, the urethane (meth)acrylate resin is preferably a compound containing a polyester segment and / or a compound containing a polyether segment. Such a compound can be obtained by using a polyether polyol or a polyester polyol as the polyol in the reaction for producing the urethane (meth)acrylate resin. In one embodiment, the weight average molecular weight of the urethane (meth)acrylate resin may preferably be 5,000 to 50,000, more preferably 5,200 to 46,000, and still more preferably 15,000 to 30,000.

[0051] Hereinafter, typical compounds that can be used as raw materials for the urethane (meth)acrylate resin will be described.

[0052] The polyisocyanate is not particularly limited, and examples thereof include tolylene diisocyanate, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer diisocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group. It is preferably bifunctional from the viewpoint of reaction control.

[0053] The (meth)acrylate compound having a hydroxyl group is not particularly limited, and examples thereof include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylates, glycerin (meth)acrylate, glycerin di(meth)acrylate, diglycerin di(meth)acrylate, diglycerin tri(meth)acrylate, trimethylolpropane (meth)acrylate, trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and the like.

[0054] Examples of the polyol include glycols, polyether polyols, and polyester polyols.

[0055] Examples of the glycols include compounds having two hydroxyl groups such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, and neopentyl glycol.

[0056] Examples of the polyether polyols that can be used include polymers, copolymers, and graft copolymers of alkylene oxides such as tetrahydrofuran, ethylene oxide, propylene oxide, butylene oxide, oxacyclobutane, and oxacycloheptane; and polyether polyols formed by condensation of hexanediol, methylhexanediol, heptanediol, octanediol, or mixtures thereof, which have two or more hydroxyl groups. Furthermore, glycols obtained by adding alkylene oxides such as ethylene oxide to bisphenols such as bisphenol A and bisphenol F can also be used.

[0057] Examples of the polyester polyols include polyester polyols obtained by a condensation reaction of a polyhydric alcohol component and a polybasic acid component.

[0058] As the polyhydric alcohol, at least one of a dihydric alcohol and a trihydric or higher alcohol can be used. The dihydric alcohol is not particularly limited, and linear, branched, or cyclic alkylene dihydric alcohols can be used. Examples of the linear alkylene dihydric alcohol include 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2-dodecanediol, 1,14-tetradecanediol, 1,2-tetradecanediol, 1,16-hexadecanediol, 1,2-hexadecanediol, etc. Examples of the branched alkylene dihydric alcohol include 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-dimethylpentanediol, 2,2-diethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dimethylol octane, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, etc. Examples of the cyclic alkylene dihydric alcohol include 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cycloheptanediol, tricyclodecanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S, hydrogenated catechol, hydrogenated resorcinol, hydrogenated hydroquinone, and the like.

[0059] The polyhydric alcohol having a trivalent or higher valence is not particularly limited, and examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerin, ditrimethylolpropane, sorbitan, sorbitol, dipentaerythritol, inositol, tripentaerythritol, and the like.

[0060] The polybasic acid is not particularly limited, and may be either aliphatic or alicyclic. Examples of the aliphatic polybasic acid include alkenyl succinic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, dodecenyl succinic acid, pentadecenyl succinic acid, and the like, and examples of the aromatic polybasic acid include orthophthalic acid, isophthalic acid, terephthalic acid, hymic acid, 3-methylhymic acid, 4-methylhymic acid, trimellitic acid, pyromellitic acid, 1,8-naphthalic acid, and anhydrides thereof. Examples of the alicyclic polybasic acid include 1,2,3,6-tetrahydrophthalic acid, 3-methyl-1,2,3,6-tetrahydrophthalic acid, 4-methyl-1,2,3,6-tetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, and anhydrides thereof.

[0061] Furthermore, compounds having three or more hydroxyl groups such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol, and methyl glucoside can also be used as the polyhydric alcohol.

[0062] Here, the above polyol can be used without particular limitation. It may be used alone according to each characteristic, or two or more thereof may be used in combination. For example, from the viewpoints of the transparency and the wet heat resistance of the coating film, the use of a polyether polyol is preferable, and it is more preferable to mainly use a polyol having a polypropylene glycol skeleton. Further, from the viewpoints of the adhesive strength and the heat resistance, the use of a polyester polyol is preferable.

[0063] <(meth)acrylate compound (B)> In one embodiment of the present invention, the (meth)acrylate compound (B) is a (meth)acrylate compound having a weight average molecular weight of 700 to 3,000 and a weight average molecular weight of 100 to 300 per (meth)acryloyl group. The weight average molecular weight of the (meth)acrylate compound (B) may preferably be 750 to 2,500, more preferably 800 to 2,000, still more preferably 900 to 1,800, and particularly preferably 1,000 to 1,700. When the weight average molecular weight and the weight average molecular weight per (meth)acryloyl group are within the above ranges, the balance of low migration property, film strength, and adhesion is excellent.

[0064] In one embodiment, as the (meth)acrylate compound (B), any (meth)acrylate compound having a weight average molecular weight of 700 to 3,000 and a weight average molecular weight of 100 to 300 per (meth)acryloyl group can be preferably used. More preferably, one or more selected from the group consisting of amine-modified (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, urethane (meth)acrylate, silicone (meth)acrylate, epoxy (meth)acrylate, and epoxidized vegetable oil (meth)acrylate can be used. In one embodiment, the (meth)acrylate compound (B) preferably contains amine-modified (meth)acrylate and / or polyester (meth)acrylate.

[0065] In one embodiment, the amine-modified (meth)acrylate is a (meth)acrylate compound having one or more amino groups in the molecule.

[0066] In one embodiment, the amine-modified (meth)acrylate preferably has an amine equivalent of 400 to 2,500. When the amine equivalent is 400 to 2,500, all of surface curability, film strength, and ground stain resistance during lithographic printing with water are good.

[0067] Here, in the above embodiment, the amine equivalent can be calculated as the molecular weight per active hydrogen derived from the amine in the amine-modified (meth)acrylate.

[0068] In one embodiment, the amine-modified (meth)acrylate is preferably contained in an amount of 0.5 to 10% by mass in the total mass of the electron beam curable composition. When the content is within this range, all of surface curability, film strength, and ground stain resistance during lithographic printing with water are good.

[0069] In one embodiment, examples of the amine-modified (meth)acrylate include EBECRYL LEO 10553 (weight average molecular weight 780, number of acryloyl groups per molecule 4, weight average molecular weight per acryloyl group 195), EBECRYL80 (weight average molecular weight 1000, number of acryloyl groups per molecule 4, weight average molecular weight per acryloyl group 250), etc. manufactured by DAICEL-ALLNEX.

[0070] In one embodiment of the present invention, the polyester (meth)acrylate is a (meth)acrylate compound having a polyester structure in the molecule (excluding the case having an amino group).

[0071] In one embodiment, the polyester (meth)acrylate desirably has 3 to 10 acryloyl groups in the molecule.

[0072] In one embodiment, it is desirable that the polyester (meth) acrylate be contained in an amount of 10 to 50% by mass based on the total mass of the electron beam curable composition. When the content is 10 to 50% by mass, all of the adhesion, viscoelasticity, and emulsifiability during lithography with water are improved.

[0073] In one embodiment of the present invention, examples of the polyester (meth) acrylate include EBECRYL LEO10801 (weight average molecular weight 1,500, number of acryloyl groups per molecule 6), EBECRYL450 (weight average molecular weight 1,600, number of acryloyl groups per molecule 6), EBECRYL800 (weight average molecular weight 780, number of acryloyl groups per molecule 4), EBECRYL810 (weight average molecular weight 1,000, number of acryloyl groups per molecule 4), EBECRYL812 (weight average molecular weight 800, number of acryloyl groups per molecule 3), EBECRYL846 (weight average molecular weight 1,100, number of acryloyl groups per molecule 6), EBECRYL870 (weight average molecular weight 1,500, number of acryloyl groups per molecule 6), etc. manufactured by DAICEL-ALNEX.

[0074] In one embodiment, from the viewpoint of the viscoelasticity of the ink, it is more preferable to use the amine-modified (meth) acrylate and the polyester acrylate in combination as the (meth) acrylate compound (B).

[0075] In one embodiment, as the (meth) acrylate compound (B), polyether (meth) acrylate, urethane (meth) acrylate, silicone (meth) acrylate, epoxy (meth) acrylate, epoxidized vegetable oil (meth) acrylate, etc. can also be used. As long as these have a weight average molecular weight of 700 to 3,000 and a weight average molecular weight per (meth) acryloyl group of 100 to 300, known materials can be used. For these polyether (meth) acrylate, urethane (meth) acrylate, silicone (meth) acrylate, epoxy (meth) acrylate, epoxidized vegetable oil (meth) acrylate, etc., modified products with various modifications may be used.

[0076] In one embodiment of the present invention, the ratio (B / A) of the content (A mass %) of the resin (A) to the content (B mass %) of the (meth)acrylate compound (B) in the total mass of the composition is preferably 0.5 to 8.0, more preferably 2.0 to 4.0. When the ratio (B / A) of the content (mass %) of the resin (A) and the (meth)acrylate compound (B) in the total mass of the composition is 0.5 to 8.0, it is possible to achieve both the required adhesion and the viscoelasticity of the ink when lithographic printing ink is made with water.

[0077] In an embodiment of the present invention, the pigment (C) may be a colored pigment or a extender pigment. The colored pigments are roughly classified into white and other color-toned pigments. The colored pigment may be either an inorganic pigment or an organic pigment. By using an organic pigment, white ink and color inks having other color tones can be formed.

[0078] In one embodiment, specific examples of the inorganic pigment among the colored pigments include lead yellow, zinc yellow, ultramarine blue, cadmium red, titanium oxide, zinc white, Indian red, ultramarine, carbon black, graphite, and aluminum powder.

[0079] In addition, in one embodiment, as specific examples of organic pigments among colored pigments, soluble azo pigments such as β-naphthol-based, β-oxynaphthoic acid-based, β-oxynaphthoic acid arylide-based, acetoacetic acid arylide-based, and pyrazolone-based, insoluble azo pigments such as β-naphthol-based, β-oxynaphthoic acid arylide-based, acetoacetic acid arylide-based monoazo, acetoacetic acid arylide-based disazo, and pyrazolone-based, copper phthalocyanine blue, halogenated (chlorinated or brominated) copper phthalocyanine blue, and sulfonated copper phthalocyanine blue, phthalocyanine-based pigments such as metal-free phthalocyanine, polycyclic pigments and heterocyclic pigments such as quinacridone-based, dioxazine-based, threne-based (pyranthrone, anthraanthrone, indanthrone, anthrapyrimidine, flavanthrone, thioindigo-based, anthraquinone-based, perinone-based, perylene-based, etc.), isoindolinone-based, metal complex-based, quinophthalone-based, etc. may be mentioned.

[0080] In one embodiment, the colored pigment may be used alone, in combination of two or more, or in combination with one or more extender pigments described later.

[0081] In one embodiment, if it is a color ink, it is desirable to contain 2 to 30% by mass, more preferably 5 to 25% by mass of the colored pigment in the total mass of the electron beam curable composition. If it is a white ink, it is desirable to contain 30 to 70% by mass, more preferably 40 to 60% by mass of titanium oxide in the total mass of the electron beam curable composition. Further, when adjusting a transparent ink (also called varnish) and a medium for dilution using extender pigments as described later, it is not necessary to contain a colored pigment in the electron beam curable composition.

[0082] In one embodiment of the present invention, the extender pigment means a pigment having no coloring power and is distinguished from the aforementioned colored pigments. In an embodiment of the present invention, specific examples of the extender pigment include barium sulfate, alumina white, calcium carbonate, magnesium carbonate, aluminum silicate, magnesium silicate, silicon dioxide, and aluminum hydroxide. These may be used alone or in combination of two or more.

[0083] In one embodiment, when the content of the extender pigment is used in the applications of electron beam curable compositions as color inks and white inks (which may be collectively referred to as inks), it is preferably adjusted according to the purpose. For example, for the purpose of improving the fluidity and anti-misting property of the ink, it is preferably used at 5% by mass or less in the total mass of the electron beam curable composition. In one embodiment, the extender pigment may not be used during the preparation of the ink. On the other hand, when the electron beam curable composition is used in the application of transparent ink (varnish), the content of the extender pigment is preferably adjusted according to the application. In one embodiment, the extender pigment is preferably used at a content of 30% by mass or less in the total mass of the electron beam curable composition (varnish). In the embodiment of the varnish, the content of the extender pigment may preferably be 0.1 to 30% by mass, more preferably 0.5 to 20% by mass, and still more preferably 1 to 10% by mass.

[0084] In one embodiment of the present invention, the total content of the resin (A), the (meth)acrylate compound (B), and the pigment (C) may be 60 to 90% by mass based on the total mass of the electron beam curable composition. When the total content of the resin (A), the (meth)acrylate compound (B), and the pigment (C) is 60 to 90% by mass based on the total mass of the composition, the necessary printing properties such as viscoelasticity, fluidity, and transferability required for water-based lithographic printing can be easily obtained.

[0085] When the electron beam curable composition of the above embodiment is used as a color ink, the total content of (A), (B) and (C) is preferably 60 to 80% by mass, more preferably 65 to 75% by mass. When the electron beam curable composition of the above embodiment is used as a white ink, the total content of (A), (B) and (C) is preferably 70 to 90% by mass, more preferably 75 to 85% by mass. When the electron beam curable composition of the above embodiment is used as a varnish and a medium, the total content of (A), (B) and (C) is preferably 60 to 80% by mass, more preferably 65 to 75% by mass.

[0086] In the above embodiment, as components other than (A), (B) and (C), it is preferable to contain a (meth)acrylate compound different from (A) and the (meth)acrylate compound (B) (hereinafter referred to as "other (meth)acrylate compound"). In the above embodiment, the content of the other (meth)acrylate compound may be 10 to 40% by mass based on the total mass of the electron beam curable composition. However, from the viewpoint of suppressing migration, it is preferable to use a compound having a weight average molecular weight of 500 or more as the other (meth)acrylate compound. When a compound having a weight average molecular weight of less than 500 is used as the other (meth)acrylate compound, as described later, its content is preferably 25% by mass or less.

[0087] In the above embodiment, the other (meth)acrylate compound can be appropriately selected according to the required cured film properties, and may be used alone or in combination of two or more. In the above embodiment, the other (meth)acrylate compound preferably has a weight average molecular weight of 500 or more and is composed of a trifunctional or higher functional (meth)acrylate compound from the viewpoints of curability and low migration.

[0088] (Electron beam curable varnish) In one embodiment, the electron beam curable composition can be produced by mixing a resin (A), a (meth)acrylate compound (B), and a pigment (C). In other embodiments, the electron beam curable composition can also be produced using an electron beam curable varnish containing the resin (A) described below.

[0089] The electron beam curable varnish can be prepared using a resin (A) and a (meth)acrylate compound. Although not particularly limited, the electron beam curable varnish preferably contains 10 to 80% by mass of the resin (A) and 20 to 90% by mass of the (meth)acrylate compound based on the total mass of the varnish. More preferably, it may contain 20 to 70% by mass of the resin (A) and 30 to 80% by mass of the (meth)acrylate compound.

[0090] In the embodiment of the electron beam curable varnish, the (meth)acrylate compound may be any one that can adjust the viscosity of the varnish to a desired range, and either the (meth)acrylate compound (B) or other (i.e., different from the (meth)acrylate compound (B)) (meth)acrylate compounds can be used. In one embodiment, the electron beam curable varnish may be prepared using a resin (A) and a (meth)acrylate compound different from the (meth)acrylate compound (B). In such an embodiment, the electron beam curable composition can be produced by further adding and mixing the (meth)acrylate compound (B) and the pigment (C) to the varnish. The blending amount of the varnish is preferably adjusted so that the ratio (B / A) of the respective contents of the resin (A) and the (meth)acrylate compound (B) in the electron beam curable composition is within a predetermined range in consideration of the content of the resin (A) in the varnish.

[0091] In one embodiment, the (meth)acrylate compound (other (meth)acrylate compounds) other than the resin (A) and the (meth)acrylate compound (B) used in producing the electron beam curable varnish and the electron beam curable composition preferably has a weight average molecular weight of 500 or more from the viewpoint of ensuring low migration properties. The weight average molecular weight of the above (meth)acrylate compound may be more preferably 550 or more, still more preferably 650 or more, and even more preferably 750 or more. However, in the present embodiment, the use of a (meth)acrylate compound having a weight average molecular weight of less than 500 is not excluded. In one embodiment, the electron beam curable varnish and the electron beam curable composition may contain a (meth)acrylate compound having a weight average molecular weight of less than 500.

[0092] In one embodiment, the content of the (meth)acrylate compound having a weight average molecular weight of less than 500 may preferably be 25% by mass or less, more preferably 20% by mass or less, and still more preferably 15% by mass or less based on the total mass of the composition. The above content may be 0% by mass. When the content of the (meth)acrylate compound having a weight average molecular weight of less than 500 is adjusted within the above range, it becomes easy to ensure low migration properties.

[0093] Although not particularly limited, specific examples of the (meth)acrylate compound having a weight average molecular weight of less than 500 are as follows. Examples of monofunctional (meth)acrylate compounds 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-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, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, acryloylmorpholine, N-vinylcarbazole, 1-vinylimidazole, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, N-vinylformamide, and the like.

[0094] As the bifunctional (meth)acrylate compounds, there may be mentioned hexanediol diacrylate, tripropylene glycol diacrylate, 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, neopentyl glycol hydroxypivalate di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, EO-modified 1,6-hexanediol di(meth)acrylate, PO-modified neopentyl glycol di(meth)acrylate, (neopentyl glycol-modified) trimethylolpropane di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, and the like.

[0095] As the trifunctional or higher functional (meth)acrylate compounds, there may be mentioned trimethylolpropane triacrylate, trimethylolpropane EO-modified (3 mol) triacrylate, trimethylolpropane PO-modified (3 mol) triacrylate, pentaerythritol triacrylate, glycerin PO-modified (3 mol) triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, and the like.

[0096] As the (meth)acrylate compound having a weight average molecular weight of less than 500, one of the exemplified compounds may be used alone or in combination of two or more. In one embodiment, it is preferable to use a polyfunctional (meth)acrylate. As the polyfunctional (meth)acrylate, it is preferable to use at least one of a bifunctional (meth)acrylate compound and a trifunctional or higher (meth)acrylate compound, and it is more preferable to use a trifunctional or higher (meth)acrylate compound.

[0097] The electron beam curable varnish of the above embodiment may contain a polymerization inhibitor described later in addition to the above components. In such an embodiment, the polymerization inhibitor can be added and used by a conventional method. When the polymerization inhibitor is added to the varnish, the blending amount is preferably 3% by mass or less, and more preferably in the range of 0.01 to 1% by mass based on the total mass of the electron beam curable varnish.

[0098] In an embodiment of the present invention, the electron beam curable varnish can be produced, for example, by mixing the above components under temperature conditions between normal temperature and 160°C. For example, it can be produced by mixing a resin (A) containing at least one selected from the group consisting of diallyl phthalate resin, rosin-modified resin, polyester resin, urethane (meth)acrylate resin, and non-phthalate type allyl resin without a phthalate structure, a polyfunctional (meth)acrylate compound such as dipentaerythritol hexaacrylate, and a polymerization inhibitor containing hydroquinone. In one embodiment, for example, a varnish obtained by heating and melting rosin-modified resin, dipentaerythritol hexaacrylate, and hydroquinone under a temperature condition of 100°C can be preferably used.

[0099] (Polymerization inhibitor) In one embodiment of the present invention, the electron beam curable composition may further contain a polymerization inhibitor in addition to the above components. In such an embodiment, the polymerization inhibitor can be added and used by a conventional method. When adding the polymerization inhibitor, from the viewpoint of not inhibiting the curability, its blending amount is preferably 3% by mass or less, more preferably in the range of 0.01 to 1% by mass, based on the total mass of the electron beam curable composition.

[0100] Specific examples of the polymerization inhibitor include (alkyl)phenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, t-butylcatechol, t-butylhydroquinone, pyrogallol, 1,1-picrylhydrazyl, phenothiazine, p-benzoquinone, nitrosobenzene, 2,5-di-tert-butyl-p-benzoquinone, dithiobenzoyl disulfide, picric acid, cupferron, aluminum N-nitrosophenylhydroxylamine, tri-p-nitrophenylmethyl, N-(3-oxyanilino-1,3-dimethylbutyrylidene)aniline oxide, dibutyl cresol, cyclohexanone oxime cresol, guaiacol, o-isopropylphenol, butyraldoxime, methyl ethyl ketoxime, cyclohexanone oxime, di-t-butyl-7-phenylquinone methide, and the like.

[0101] In particular, compounds having two hydrocarbon groups each (a total of four) at the 2-position and 6-position on the piperidine ring are preferred. More specifically, it is preferable to use one or more compounds selected from hindered amine systems such as 2,2,6,6-tetraalkylpiperidine derivatives, 2,2,6,6-tetramethylpiperidine derivatives, 1-alkyl-2,2,6,6-tetramethylpiperidine derivatives or 1-hydro-2,2,6,6-tetramethylpiperidine derivatives. When using such a compound, the curing reaction in a printing machine can be inhibited, and excellent storage stability can be easily provided. The above compounds can also be obtained as commercially available products. For example, the product name "Poly Stop 7300P" (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl) manufactured by Hakuto Co., Ltd. can be mentioned.

[0102] (Various additives) In one embodiment of the present invention, the electron beam curable composition may further contain various additives such as a viscoelasticity modifier, a dispersant, an antifriction agent, an antiblocking agent, a lubricant, etc., according to the purpose. The various additives can be added to the composition by a conventional method. When adding the various additives to the composition, it is preferable to adjust the blending amount within a range that does not inhibit the effects of other components. The blending amount of the various additives is preferably 5% by mass or less based on the total mass of the electron beam curable composition.

[0103] On the other hand, in recent years, there has been concern about global pollution caused by persistent organic pollutants having characteristics such as recalcitrance, high bioaccumulation, long-range mobility, and harmfulness (to human health and the ecosystem). For example, regulations are progressing, represented by the Stockholm Convention on Persistent Organic Pollutants (POPs Convention) which came into force in May 2004. Polytetrafluoroethylene wax is used as an antifriction agent for printing inks, but may contain persistent organic pollutants such as PFAS. Therefore, it is preferable that the electron beam curable composition which is one embodiment of the present invention does not substantially contain polytetrafluoroethylene wax.

[0104] Here, in the embodiment of the present invention, "substantially not contained" means that the target component is not intentionally added and the content due to unintentional addition is less than 1% by mass. Unintentional addition includes cases where it is contained in trace amounts in each raw material, and contamination in the manufacturing process of the composition and the process of producing printed matter.

[0105] In one embodiment of the present invention, the electron beam curable composition substantially does not contain an organic solvent. There is a concern that the organic solvent used as a viscosity modifier for printing ink contains MOSH / MOAH which are persistent organic pollutants. Also, by not containing volatile components (Non-VOC), reduction of environmental load and improvement of work safety can be expected. For these reasons, in the embodiment of the present invention, it is preferable that the electron beam curable composition substantially does not contain an organic solvent.

[0106] In one embodiment of the present invention, the electron beam curable composition substantially does not contain a photoinitiator. A photoinitiator can be expected to exhibit and improve the curability of the active energy ray curable composition. On the other hand, in the packaging market, especially in food packaging materials, toiletry packaging materials, medical packaging materials, etc., there is a concern that the components of the photoinitiator may migrate, resulting in a decrease in safety and quality. For these reasons, in the embodiment of the present invention, it is preferable that the electron beam curable composition substantially does not contain a photoinitiator.

[0107] In one embodiment of the present invention, as various raw materials used in the electron beam curable composition, from the perspective of carbon neutrality, etc., raw materials derived from biomass using renewable resources such as plants can preferably be used.

[0108] In one embodiment of the present invention, when the electron beam curable composition is used as a lithographic ink, the ink can be produced by flashing, kneading, and mixing the above-mentioned respective constituent components under temperature conditions from room temperature to 120°C. To produce the ink, it is preferable to use various equipment such as a kneader, a three-roll mill, an attritor, a sand mill, a gate mixer, etc. In the production of the ink, the resin (A) may be added in the form of the resin (A) itself, or may be added in the form of an electron beam curable varnish containing the above resin (A).

[0109] <Laminate> A laminate according to an embodiment of the present invention includes a base material and a printing layer formed on at least one main surface of the base material and composed of a cured product of the electron beam curable composition of the above embodiment. In one embodiment of the present invention, when the electron beam curable composition is an electron beam curable ink, the laminate is obtained by printing the electron beam curable ink on the base material to form a coating film and curing this coating film with an electron beam. Further, when the electron beam curable composition is an electron beam curable varnish, the laminate is obtained by printing the electron beam curable varnish on the base material or printing the electron beam curable varnish on a printed matter obtained by printing ink on the base material to form a coating film and curing this coating film with an electron beam.

[0110] In the above embodiment, the base material that can be used is preferably a film-like base material. For example, polyolefin base materials such as polyethylene and polypropylene, polyester base materials such as polyethylene terephthalate and polylactic acid, polycarbonate base materials, polystyrene-based base materials such as polystyrene, AS resin, and ABS resin, nylon base materials, polyamide base materials, polyvinyl chloride base materials, polyvinylidene chloride base materials, cellophane base materials, paper base materials, aluminum base materials, etc., or film-like base materials made of these composite materials can be mentioned. Further, as the base material, a vapor-deposited base material in which inorganic compounds such as silica, alumina, and aluminum are vapor-deposited on a polyethylene terephthalate base material or a nylon base material can also be used, and further, the vapor-deposited surface may be subjected to a coating treatment with polyvinyl alcohol or the like. The base material preferably has its surface to be printed (the surface in contact with the printing layer) subjected to an easy adhesion treatment. Examples of the easy adhesion treatment include corona discharge treatment, ultraviolet / ozone treatment, plasma treatment, oxygen plasma treatment, primer treatment, etc. Also, in the case of a polyethylene terephthalate base material, when sufficient adhesion cannot be obtained, an acrylic coating treatment, a polyester treatment, a polyvinylidene chloride treatment, etc. may be performed.

[0111] A paper base material may be used as the base material. The paper base material may be ordinary paper, cardboard, etc. Although there is no particular specification for the film thickness of the paper base material, for example, 0.2 mm to 1.0 mm, 20 to 150 g / m2 Those can be used, and the printing surface may be subjected to an easy adhesion treatment. The paper substrate may have its surface vapor-deposited with a metal such as aluminum for the purpose of imparting design properties. Further, it may be surface-coated with an acrylic resin, a urethane resin, a polyester resin, a polyolefin resin, or other resins, and may further be subjected to a surface treatment such as a corona treatment. For example, coated paper, art paper, etc. may be mentioned.

[0112] In one embodiment of the present invention, the printing method of the electron beam curable composition is not particularly limited, and a known method can be used. When the electron beam curable composition is an ink, specifically, water-based offset printing (ordinary lithography using dampening water), waterless offset printing (lithography without using dampening water), resin letterpress printing, screen printing, etc. are used. Among them, it is preferable to use offset printing, and more preferably water-based offset printing.

[0113] Also, similarly, when the electron beam curable composition is a varnish, applications where it is preferably used include water-based offset printing, waterless offset printing, resin letterpress printing, and screen printing. In addition, by adjusting the viscoelasticity, various printing methods such as flexographic printing, gravure printing, inkjet printing, etc., and coating with various coaters can also be selected.

[0114] In one embodiment, after the electron beam curable composition is printed by various printing methods (after the coating film of the composition is formed), the coating film is cured through an electron beam irradiator to form a printed layer. The electron beam used for curing is desirably irradiated in consideration of the balance between the damage to the substrate such as a film and the curability of the electron beam curable composition. In one embodiment, it is desirable to irradiate an electron beam adjusted under the conditions of an acceleration voltage of 40 to 120 kV, preferably 60 to 110 kV, and an irradiation dose of 10 to 60 kGy, more preferably 15 to 45 kGy. When the irradiation dose is 10 to 60 kGy, sufficient film strength can be obtained, and problems due to damage to the film such as a decrease in film strength, odor, and yellowing can be suppressed.

[0115] The electron beam curable composition of the above embodiment can be suitably used for forming a printing layer on various substrates. In addition, it can also be applied to form various printed materials such as printed materials for foams, printed materials for various books, various packaging printed materials such as cardboard, various plastic printed materials, printed materials for seals / labels, art printed materials, and metal printed materials (art printed materials, printed materials for beverage cans, food printed materials such as canned foods). In one embodiment, the electron beam curable composition can be suitably used as an ink or a varnish for forming a packaging material for food packages (hereinafter also referred to as a packaging material for foods).

[0116] One embodiment of the present invention relates to a method for manufacturing a laminate having a substrate and a layer composed of a cured product of an electron beam curable composition formed on the substrate. This manufacturing method includes printing the electron beam curable composition of the above embodiment on the substrate to form a coating film, and irradiating the coating film with an electron beam to cure the coating film. In the above embodiment, it is preferable that the curing of the coating film is carried out by irradiating the electron beam under the conditions of an acceleration voltage of 40 to 120 kV and an irradiation dose of 10 to 60 kGy. Further, the electron beam curable composition contains a resin (A) having a weight average molecular weight of 5,000 to 50,000, a (meth)acrylate compound (B) having a weight average molecular weight of 700 or more to 3,000 and a weight average molecular weight of 100 to 300 per (meth)acryloyl group, and a pigment (C). The resin (A) preferably contains one or more selected from the group consisting of a rosin-modified resin, a urethane (meth)acrylate resin, a polyester resin, and a diallyl phthalate resin. The (meth)acrylate compound (B) preferably contains one or more selected from the group consisting of an amine-modified (meth)acrylate and a polyester (meth)acrylate.

[0117] In one embodiment, the laminate may have a structure for use as a food packaging material. For example, it may be a laminate in the form of surface printing, having a printing layer formed from an ink or varnish of an electron beam curable composition on one side of a film serving as a base material, and having a metal foil, various films, a sealant layer, etc. on the other side of the film via an adhesive layer. In one embodiment, the food packaging material may be processed into various package forms such as the shape of a lid for a container, a bag shape such as a pouch, etc.

[0118] In a laminate in the form of surface printing, the outermost layer of the food packaging material (package) is the printing layer. Therefore, by improving the film strength of the printing layer formed from the ink or varnish of the electron beam curable composition of the above embodiment, problems such as rubbing and breakage of the package due to vibration and friction generated during transportation can be easily improved. Thus, in a laminate in the form of surface printing, the benefits due to the improvement of the film strength become prominent. However, the laminate is not limited to the form of surface printing and may be in the form of reverse printing. In a laminate in the form of reverse printing, since it has a structure in which a film or the like is further laminated on the printing layer on the base material, problems such as rubbing and breakage are less likely to occur. However, by forming the printing layer using the ink or varnish of the electron beam curable composition of the above embodiment, characteristics such as excellent adhesion to the base material and low migration required for the food packaging material can be easily obtained.

[0119] Also, in one embodiment, in the laminate, for example, in the migration resistance test described later, it is preferable that the concentration of the (meth)acrylate compound having the largest migration amount is less than 50 ppb. (Migration Resistance Test) Using a plastic film such as an OPP film as the base material, an electron beam curable composition (ink or varnish) is applied to one side of this film at 2 - 3 g / m 2Print to achieve the coating amount to form a coating film. With respect to this coating film, use an electron beam irradiator to irradiate the electron beam to cure the coating film and form a printed surface. The irradiation conditions may be, for example, an acceleration voltage of 110 kV and an electron beam dose of 30 kGy. Thereafter, stack and hold the printed surface of the substrate and the non-printed surface of another substrate in contact with each other. More specifically, for example, under a load addition of 1 kg / dm 2 it can be held for 10 days under environmental conditions of 25°C and 50%. Thereafter, extract the residual monomer (unreacted (meth)acrylate component) with ethanol. More specifically, for example, with respect to an area of 0.5 dm 2 of the non-printed surface, extract the residual monomer with 50 ml of 95% ethanol at 60°C for 10 days. Next, use a quadrupole-time-of-flight mass spectrometer and a liquid chromatograph to analyze the above extract and determine the concentration of each (meth)acrylate compound present in ethanol.

[0120] Since the laminate of the above embodiment can easily satisfy the requirements for safety such as low migration properties, it can be suitably used in the application of food packaging materials.

Example

[0121] Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited by these examples. In addition, "parts" described in this specification represent parts by mass, and "%" represents mass%.

[0122] The details of various measurements performed in the following examples are as follows.

[0123] (Component analysis of rosin acids) The rosin acids used as raw materials were analyzed with a gas chromatography mass spectrometer, and the area ratio (%) of each peak was determined with respect to the total rosin acid peak area of 100%. More specifically, the content ratios of the conjugated rosin acids contained in the rosin acids that undergo a Diels-Alder addition reaction with an α,β-unsaturated carboxylic acid or its acid anhydride (B) and those other than the conjugated rosin acids were determined from the ratios of the corresponding peak areas, respectively.

[0124] (Confirmation of the progress of the Diels-Alder addition reaction and quantification of the above-mentioned addition reaction product formed) The reaction solution of the Diels-Alder addition reaction was analyzed with a gas chromatography mass spectrometer, and the progress of the reaction was confirmed by the decrease in the detection peaks of the rosin acids (a1) and the α,β-unsaturated carboxylic acid or its acid anhydride (a2) used as raw materials. The reaction was terminated when no change was observed in the decrease of the detection peaks.

[0125] (Measurement of weight average molecular weight) The weight average molecular weight (Mw) was measured using gel permeation chromatography (HLC-8320) manufactured by Tosoh Corporation. The calibration curve was prepared with standard polystyrene samples. Tetrahydrofuran was used as the eluent, and three TSKgel SuperHM-M (manufactured by Tosoh Corporation) columns were used. The measurement was carried out under the conditions of a flow rate of 0.6 mL / min, an injection volume of 10 μL, and a column temperature of 40°C.

[0126] 1. Preparation of binder resin 1-1. Preparation of rosin-modified resin A rosin-modified resin was prepared according to the formulation shown below. The gum rosin used in the formulation shown below had a content of conjugated rosin acid that undergoes a Diels-Alder addition reaction with an α,β-unsaturated carboxylic acid or its acid anhydride (a2) of 80% by mass and a content of those other than the conjugated rosin acid of 20% by mass.

[0127] (Preparation of rosin-modified resin 1) Into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, 52.9 parts of gum rosin, 37.0 parts of phthalic anhydride, 10.0 parts of glycerin, and 0.1 part of p-toluenesulfonic acid monohydrate as a catalyst were added, and a dehydration condensation reaction was carried out at 230 °C for 6 hours to obtain rosin-modified resin 1.

[0128] (Preparation of rosin-modified resin 2) Into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, 50.0 parts of gum rosin, 41.9 parts of tetrahydrophthalic anhydride, 8.0 parts of glycerin, and 0.1 part of p-toluenesulfonic acid monohydrate as a catalyst were added, and a dehydration condensation reaction was carried out at 230 °C for 7 hours to obtain rosin-modified resin 2.

[0129] (Preparation of rosin-modified resin 3) Into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, 25.0 parts of gum rosin and 15.9 parts of maleic anhydride were charged, and while blowing nitrogen gas, the mixture was heated at 180 °C for 1 hour to obtain a reaction mixture. To the reaction mixture, 38 parts of benzoic acid, 5.0 parts of trimethylolpropane, 16.0 parts of pentaerythritol, and 0.1 part of p-toluenesulfonic acid monohydrate as a catalyst were added, and a dehydration condensation reaction was carried out at 230 °C for 9 hours to obtain rosin-modified resin 3.

[0130] (Preparation of rosin-modified resin 4) Into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, 27.0 parts of gum rosin and 17.0 parts of maleic anhydride were charged, and while blowing nitrogen gas, the mixture was heated at 180 °C for 1 hour to obtain a reaction mixture. To this reaction mixture, 31.9 parts of benzoic acid, 8.0 parts of trimethylolpropane, 16.0 parts of pentaerythritol, and 0.1 part of p-toluenesulfonic acid monohydrate as a catalyst were added, and a dehydration condensation reaction was carried out at 230 °C for 10 hours to obtain rosin-modified resin 4.

[0131] (Preparation of rosin-modified resin 5) Into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, 38.5 parts of gum rosin and 27.0 parts of maleic anhydride were charged, and while blowing nitrogen gas, it was heated at 180 °C for 1 hour to obtain a reaction mixture. To this reaction mixture, 11.6 parts of tetrahydrophthalic anhydride, 14.8 parts of glycerin, 8.0 parts of pentaerythritol, and 0.1 part of p-toluenesulfonic acid monohydrate as a catalyst were added, and a dehydration condensation reaction was carried out at 230 °C for 12 hours to obtain rosin-modified resin 5.

[0132] (Preparation of rosin-modified resin 6) Into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, 37.0 parts of gum rosin and 30.0 parts of maleic anhydride were charged, and while blowing nitrogen gas, it was heated at 180 °C for 1 hour to obtain a reaction mixture. To this reaction mixture, 9.9 parts of tetrahydrophthalic anhydride, 15.0 parts of glycerin, 8.0 parts of pentaerythritol, and 0.1 part of p-toluenesulfonic acid monohydrate as a catalyst were added, and a dehydration condensation reaction was carried out at 230 °C for 12 hours to obtain rosin-modified resin 6.

[0133] The formulations and weight-average molecular weights of rosin-modified resins 1 to 6 are shown in Table 1 respectively.

[0134]

Table 1

[0135] In Table 1, the blending amounts of each monomer used in the preparation of resin (A) are all parts by mass of solid content.

[0136] 1-2. Preparation of urethane (meth)acrylate resin According to the formulation shown below, urethane (meth)acrylate resin was prepared.

[0137] (Preparation of polyester polyol 1) Into a four-necked flask equipped with a stirrer, a Dean-Stark tube, a thermometer, and a gas inlet tube, 36.2 parts of ethylene glycol and 63.8 parts of adipic acid were placed as raw materials, and the mixture was heated to 220 °C while stirring. The reaction was carried out while removing the condensed water generated during the progress of the reaction outside the system, and the reaction was terminated when the theoretical water removal amount was reached to obtain polyester polyol 1.

[0138] (Preparation of Polyester Polyols 2 - 6) Except that the formulation of polyester polyol 1 was changed to the formulations shown in Table 2 respectively, polyester polyol resins 2 - 6 were prepared in the same manner as the preparation of polyester polyol 1.

[0139]

Table 2

[0140] (Preparation of Urethane (Meth)acrylate Resin 1) Into a four-necked flask equipped with a stirrer, a cooler, a thermometer, and a gas inlet tube, 50.4 parts of polyester polyol 1 and 29.3 parts of hexamethylene diisocyanate were placed, and the mixture was reacted at 100 °C for 3 hours while stirring. Then, 20.3 parts of HEA was added, and the reaction was further carried out at 110 °C for 5 hours to obtain urethane (meth)acrylate resin 1.

[0141] (Preparation of Urethane (Meth)acrylate Resins 2 - 6) Except that the formulation of urethane (meth)acrylate resin was changed to the formulations shown in Table 3 respectively, urethane (meth)acrylate resins 2 - 6 were prepared in the same manner as the preparation of urethane (meth)acrylate resin 1. Also, the weight average molecular weights of urethane (meth)acrylate resins 1 - 6 are shown in Table 1. The details of the commercially available products used are as follows. HEA: 2-Hydroxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0142]

Table 3

[0143] 1-3. Preparation of polyester resin A polyester resin was prepared according to the formulation shown below. Into a four-necked flask equipped with a stirrer, a Dean-Stark tube, a thermometer, and a gas introduction tube, 10 parts of glycerin, 20 parts of ethylene glycol, and 59 parts of phthalic anhydride were placed as raw materials, and the mixture was heated to 220 °C with stirring. The reaction was carried out while removing the condensed water generated during the progress of the reaction out of the system. When the theoretical amount of water removed was reached, the reaction was terminated to obtain Polyester Resin 1 (weight average molecular weight: 10,500, hydroxyl value 119 KOH / g).

[0144] In addition, the following commercially available resins were used. · DAP-K (diallyl phthalate resin, weight average molecular weight 25,000, manufactured by Osaka Soda Co., Ltd.) · RADPAR AD-032 (non-phthalate type allyl resin, weight average molecular weight 32,000, manufactured by Osaka Soda Co., Ltd.)

[0145] 2. Preparation of varnish Into a four-necked flask equipped with a stirrer, a Dean-Stark tube, a thermometer, and a gas introduction tube, raw materials were put according to the formulation in Table 4, and the mixture was heated to 100 °C with stirring and stirred and melted at 100 °C for 2 hours to obtain Varnishes 1 to 15 described in Table 4. The details of the commercially available products used are as follows. Miramer M600: dipentaerythritol hexaacrylate (weight average molecular weight 578, number of acryloyl groups per molecule: 6, weight average molecular weight per acryloyl group: 96, manufactured by Misumi Specialty Chemicals Co., Ltd.)

[0146]

Table 4

[0147] 3. Preparation of electron beam curable lithographic ink and electron beam curable varnish (Examples 1 to 29, Comparative Examples 1 to 12) (Preparation of Electron Beam Curing Lithographic Ink and Electron Beam Curing Varnish) Each raw material was blended and mixed so as to obtain the blending ratios described in Table 5, and kneaded with a three-roll mill set at a temperature of 40°C to obtain the inks and varnishes of Examples 1 to 29 and Comparative Examples 1 to 12.

[0148] Also, for the preparation of the ink, the following commercially available materials were used. [Pigment] ·FG-7330G: LIONOL BLUE FG-7330G (blue pigment, manufactured by Toyo Ink Co., Ltd.) ·CR-90-2: Taypeak CR-90-2 (titanium oxide, manufactured by Ishihara Sangyo Co., Ltd.) ·AEROSIL200V (fumed silica, manufactured by Nippon Aerosil Co., Ltd.) ·High Filler #5000PJ (talc, manufactured by Matsumura Sangyo Co., Ltd.)

[0149] [(Meth)acrylate Compound] ·EBECRYL 10551 (amine-modified acrylate, weight average molecular weight: 500, number of acryloyl groups per molecule: 2.5, weight average molecular weight per acryloyl group: 200, manufactured by Daicel Ornex Co., Ltd.) ·EBECRYL 10553 (amine-modified acrylate, weight average molecular weight: 780, number of acryloyl groups per molecule: 4, weight average molecular weight per acryloyl group: 195, manufactured by Daicel Ornex Co., Ltd.) ·EBECRYL 80 (amine-modified acrylate, weight average molecular weight: 1,000, number of acryloyl groups per molecule: 4, weight average molecular weight per acryloyl group: 250, manufactured by Daicel Ornex Co., Ltd.) ·Laromer PO 9139 (amine-modified acrylate, weight average molecular weight: 5,900, manufactured by BASF)

[0150] · EBECRYL 851 (polyester acrylate, weight average molecular weight: 500, number of acryloyl groups per molecule: 2.5, weight average molecular weight per acryloyl group: 200, manufactured by Daicel Ornex Co., Ltd.) · EBECRYL 800 (polyester acrylate, weight average molecular weight: 780, number of acryloyl groups per molecule: 4, weight average molecular weight per acryloyl group: 195, manufactured by Daicel Ornex Co., Ltd.) · EBECRYL 810 (polyester acrylate, weight average molecular weight: 1,000, number of acryloyl groups per molecule: 4, weight average molecular weight per acryloyl group: 250, manufactured by Daicel Ornex Co., Ltd.) · EBECRYL 450 (polyester acrylate, weight average molecular weight: 1,600, number of acryloyl groups per molecule: 6, weight average molecular weight per acryloyl group: 267, manufactured by Daicel Ornex Co., Ltd.) · UF-3007 (polyester acrylate, weight average molecular weight: 3,600, number of acryloyl groups per molecule: 2.5, weight average molecular weight per acryloyl group: 1440, manufactured by Kyoeisha Chemical Co., Ltd.)

[0151] · Miramer M3150 (trimethylolpropane ethylene oxide adduct (15 moles) triacrylate, weight average molecular weight 956, number of acryloyl groups per molecule: 3, weight average molecular weight per acryloyl group: 319, manufactured by MIWON Co., Ltd.) · Miramer M3160 (trimethylolpropane ethylene oxide adduct (6 moles) triacrylate, weight average molecular weight 560, number of acryloyl groups per molecule: 3, weight average molecular weight per acryloyl group: 187, manufactured by MIWON Co., Ltd.) · Miramer M3130 (trimethylolpropane EO modified (3 moles) triacrylate, weight average molecular weight 428, number of acryloyl groups per molecule: 3, weight average molecular weight per acryloyl group: 143, manufactured by MIWON Co., Ltd.)

[0152] <Polymerization inhibitor> · Polystop 7300P (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, Hakuto Co., Ltd., trade name)

[0153]

Table 5

[0154]

Table 5-1

[0155]

Table 5-2

[0156]

Table 5-3

[0157] 4. Evaluation of Electron Beam Curing Lithographic Inks and Electron Beam Curing Varnishes For each of the electron beam curing lithographic inks and varnishes prepared in the examples and comparative examples, laminates were produced according to the following method and the following evaluations were carried out.

[0158] (Transport Vibration Test) On a PET film (Embret PTM, 12 μm), a laminate adhesive (TM-321A / TM-321B = 2 / 1, manufactured by Toyo Morton Co., Ltd.) was applied using a bar coater to form a coating film. More specifically, a diluted solution of the above adhesive diluted with ethyl acetate so that the active ingredient was 30% by mass was prepared. Using this diluted solution of the adhesive, the solid content coating amount after solvent volatilization at room temperature was adjusted to be 2.0 - 2.5 g / m 2 and applied to form a coating film. After the solvent was volatilized from the coating film in a drying oven, it was laminated with an aluminum foil (thickness 7 μm, hereinafter referred to as AL) to obtain a PET / AL laminate. Next, a laminate adhesive was applied to the AL foil surface of the obtained laminate in the same manner as above, the solvent was volatilized, and the coated surface was bonded to an OPA film (Emblem ONM, 15 μm). A laminate adhesive was applied to the OPA film surface of the obtained laminate in the same manner as above, the solvent was volatilized, and the coated surface was bonded to the corona-treated surface of an unstretched polypropylene film (FHK2 manufactured by Futamura Chemical Co., Ltd., thickness 40 μm, hereinafter referred to as "CPP"). The obtained laminate was left standing in an environment of 35°C and a humidity of 60%RT to 80%RT for 24 hours to obtain a laminate having a structure of PET / adhesive layer / AL / adhesive layer / OPA / adhesive layer / CPP.

[0159] On the PET film surface of the obtained laminate, using an RI tester (a simple color development device manufactured by Meisei Seisakusho Co., Ltd.), the inks and varnishes of Examples 1 to 27 and Comparative Examples 1 to 12 were applied to the film at a coating amount of 1 g / m 2 to form a coating film. Immediately after printing, the coating film was cured using an electron beam irradiator EC250 / 15 / 180L manufactured by Iwasaki Electric Co., Ltd. at an acceleration voltage of 110 kV and an electron beam dose of 30 kGy to obtain a laminate having a structure of ink layer (cured coating film) / PET / adhesive layer / AL / adhesive layer / OPA / adhesive layer / CPP.

[0160] Using the obtained laminate, pouches having a size of 14 cm × 18 cm were produced and filled with 150 ml of water as the content. Twenty such pouches were produced respectively, placed in a cardboard box, and subjected to a transport vibration test in the horizontal direction for 15 minutes, in the vertical direction for 15 minutes, and in the height direction for 15 minutes under the conditions of a controlled acceleration of 1G and a vibration frequency of 6 Hz, and evaluated according to the following criteria. The industrially applicable level is "3" or higher, and "4" or higher is more preferable.

[0161] (Evaluation criteria for transport vibration test) 5: No damage or peeling can be visually confirmed in any of the 20 pouches. 4: Damage or peeling can be visually confirmed in 1 pouch out of 20. 3: Damage or peeling can be visually confirmed in 2 pouches out of 20. 2: Three to ten out of 20 pouches can be visually confirmed to have scratches or peeling. 1: Eleven to twenty out of 20 pouches can be visually confirmed to have scratches or peeling.

[0162] (Adhesion test) For the electron beam curable lithographic inks and varnishes of Examples 1 to 29 and Comparative Examples 1 to 12, using an RI tester (a simple color development device manufactured by Meisei Seisakusho Co., Ltd.), they were printed on a film to a coating amount of 1 g / m 2 . Immediately after printing, the coating film was cured using an electron beam irradiator EC250 / 15 / 180L manufactured by Iwasaki Electric Co., Ltd. at an acceleration voltage of 110 kV and an electron beam dose of 30 kGy to obtain a laminate of film / printing layer (cured coating film). The obtained laminate was used to evaluate the tape adhesion. The measurement was carried out using an adhesive tape (Nichiban Co., Ltd. cellophane tape (width 12 mm)). The tape was stuck on the printing surface (the surface of the printing layer), quickly peeled off at an angle of 180 degrees, and the area percentage of the coating film remaining on the printed matter (laminate) side was evaluated in five grades according to the following criteria. The industrially practical level is "3" or more, and "4" or more is more preferable.

[0163] (Evaluation criteria for adhesion test) 5: The area of the remaining coating film is 90% or more 4: The area of the remaining coating film is 70% or more and less than 90% 3: The area of the remaining coating film is 50% or more and less than 70% 2: The area of the remaining coating film is 25% or more and less than 50% 1: The area of the remaining coating film is less than 25%

[0164] In addition, when considering adhesion, the following films were used. However, the effect of improving adhesion in the present invention is not limited to these film substrates. OPP: FOR (30 μm) manufactured by Futamura Chemical Co., Ltd. PE: White polyethylene film (50 μm) PET: Emblet PTM (12 μm) manufactured by Unitika Ltd. OPA: Emblem ONM (15 μm) manufactured by Unitika Ltd.

[0165] (Migration resistance test) On an OPP film (FOR, 30 μm, manufactured by Futamura Chemical Co., Ltd.), a laminate adhesive (TM-321A / TM-321B = 2 / 1, manufactured by Toyo Morton Co., Ltd.) was applied using a bar coater to form a coating film. More specifically, a diluted solution of the above adhesive diluted with ethyl acetate so that the active ingredient was 30% was prepared. Using this diluted solution of the adhesive, the solid content coating amount after solvent volatilization at room temperature was adjusted to 2.0 - 2.5 g / m 2 and applied to form a coating film. After volatilizing the solvent of the coating film in a drying oven, the coated surface was bonded to the corona-treated surface of an unstretched polypropylene film (FHK2, 40 μm thick, manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as "CPP"). Next, it was left standing for 24 hours in an environment of 35°C and a humidity of 60%RT - 80%RT to obtain a laminate having a structure of OPP / adhesive layer / CPP.

[0166] On the OPP film surface of the obtained laminate, using an RI tester (a simple color development device manufactured by Aki Seisakusho Co., Ltd.), the inks of Examples 1 - 29 and Comparative Examples 1 - 12 were printed on the film so that the coating amount was 2 - 3 g / m 2 . Immediately after printing, the coating film was cured using an electron beam irradiator EC250 / 15 / 180L manufactured by Iwasaki Electric Co., Ltd. at an acceleration voltage of 110 kV and an electron beam dose of 30 kGy to obtain a laminate having a structure of ink layer (cured coating film) / OPP / adhesive layer / CPP. Next, three pieces of the obtained printed matter cut into 9 cm × 9 cm were prepared, and the three pieces were overlapped so that the printed surface and the non-printed surface were in contact, and held for 10 days at 25°C and 50% environmental conditions under a load application of 1 kg / dm 2 . Then, the central printed matter among the three was taken out, and the area of the non-printed surface was 0.5 dm 2It was set in a migration cell so that 50 ml of 95% ethanol was in contact therewith. Then, while stirring was applied, the residual monomer (unreacted (meth)acrylate component) was extracted at 60° C. over 10 days. The migration cell is completely sealed by an instrument, and loss of the contents and contamination of the contents (extract) with other components can be completely suppressed in the above process. Next, using a quadrupole-time-of-flight mass spectrometer manufactured by Bruker Daltonics and an LC30A series liquid chromatograph manufactured by Shimadzu Corporation, the above extract was analyzed, and the concentration of each (meth)acrylate compound was determined as the (meth)acrylate component (A) present in ethanol. Furthermore, the migration resistance was evaluated according to the following criteria. The industrially practical level is "3" or higher, and "4" or higher is more preferable.

[0167] (Evaluation criteria for migration resistance) 5: Among the (meth)acrylate components (A), the concentration of the (meth)acrylate compound with the largest migration amount is less than 10 ppb 4: Among the (meth)acrylate components (A), the concentration of the (meth)acrylate compound with the largest migration amount is 10 ppb or more and less than 25 ppb 3: Among the (meth)acrylate components (A), the concentration of the (meth)acrylate compound with the largest migration amount is 25 ppb or more and less than 50 ppb 2: Among the (meth)acrylate components (A), the concentration of the (meth)acrylate compound with the largest migration amount is 50 ppb or more and less than 100 ppb 1: Among the (meth)acrylate components (A), the concentration of the (meth)acrylate compound with the largest migration amount is 100 ppb or more

[0168] (Evaluation of printability) Printing tests were conducted using the inks and varnishes obtained in Examples 1 to 29 and Comparative Examples 1 to 12. The printing tests were carried out using a Comexi CI-8 (an offset printing press manufactured by Comexi) on an OPP film (FOR (30 μm) manufactured by Futamura Chemical Co., Ltd.). The printing speed was 200 m / min, and the EB irradiation conditions were 110 kV and 30 kGy. In addition, in the printing test, tap water containing 3.0% of SUNFOUNT S27H (manufactured by SUNCHRMICAL) was used as dampening water. In order to compare the printing states near the boundary of the normal printing condition range, printing was performed at a water dial value 2% higher than the lower limit value of the water width. The "lower limit of the water width" means the minimum supply amount of dampening water that enables normal printing, and the "water dial" means the dial provided on the printing press to adjust the supply amount of the dampening water.

[0169] (Film Strength Test) The surface of the printed matter obtained by printing the inks of Examples 1 to 29 and Comparative Examples 1 to 12 was rubbed back and forth once per second using a cotton swab dipped in a 99.5% ethanol solution, and the number of reciprocations until the surface of the cured film was scratched was evaluated in five grades according to the following criteria. The industrially practical level is "3" or higher, and "4" or higher is more preferable. 5: 100 times or more 4: 50 times or more and less than 100 times 3: 30 times or more and less than 50 times 2: 10 times or more and less than 30 times 1: Less than 10 times

[0170] (High-Speed Printing Suitability Test) Among the inks obtained in Examples 1 to 29 and Comparative Examples 1 to 12, after adjusting the printing speed to the reference concentration at 100 m / min under the condition of fixing the conditions other than the printing speed, the printing speed was increased to 200 m / min, and the density variation when printing 500 m was evaluated in five grades according to the following criteria to evaluate the initial density stability. The practical level is "3" or higher, and "4" or higher is more preferable. 5: Density variation is less than ±5% 4: Density variation is ±5% or more and less than 10% 3: Concentration variation is ±10% or more and less than 15% 2: Concentration variation is ±15% or more and less than 20% 1: Concentration variation is ±20% or more

[0171] (Soil stain resistance test) In the above printing test, as the printing length increases, ink gradually adheres to the roller supplying dampening water. When the supply amount of dampening water decreases, ink tends to adhere to the non-printing areas (where ink should not be placed) of the printed matter where the image is being formed. From these results, as the printing length increases, dirt is likely to occur on the printed matter. Regarding the resistance to such dirt, for the reasons described above, the water dial was set to a water dial value 2% higher than the lower limit value of the water width, and the printed matter was visually inspected and evaluated in five levels according to the following criteria. The practical applicable level is "3" or more, but "4" or more is more preferable. 5: No soil stain can be confirmed especially on the film in printing of 8,000 m. 4: Soil stain occurs in the non-printing areas in printing of 6,000 m or more and less than 8,000 m. 3: Soil stain occurs in the non-printing areas in printing of 4,000 m or more and less than 6,000 m. 2: Soil stain occurs in the non-printing areas in printing of 2,000 m or more and less than 4,000 m. 1: Soil stain occurs in the non-printing areas in printing of less than 2,000 m.

[0172]

Table 6

[0173] As described above, according to the present invention, it is possible to provide an electron beam curable composition that imparts excellent adhesion to each film substrate, imparts important low migration property and transport resistance in the packaging market, and is excellent in safety for health and the environment, and a laminate using the electron beam curable composition. Further, when used as an ink, it is possible to provide an electron beam curable composition having excellent printing suitability.

Claims

1. The composition comprises: a resin (A) having a weight average molecular weight of 5,000 to 50,000; a (meth)acrylate compound (B) having a weight average molecular weight of 700 to 3,000 and a weight average molecular weight per (meth)acryloyl group of 100 to 300; and a pigment (C); The resin (A) contains at least one selected from the group consisting of a rosin-modified resin, a diallyl phthalate resin, a polyester resin, and a urethane (meth)acrylate resin; the (meth)acrylate compound (B) contains at least one member selected from the group consisting of an amine-modified (meth)acrylate and a polyester (meth)acrylate, 1. An electron beam curable composition, comprising: a (meth)acrylate compound having a weight average molecular weight of less than 500 in an amount of 25 mass % or less based on the total mass of the composition.

2. 2. The electron beam curable composition according to claim 1, wherein a ratio of a content (% by mass) of the (meth)acrylate compound (B) in the total mass of the composition to a content (% by mass) of the resin (A) in the total mass of the composition is 0.5 to 8.

0.

3. An electron beam curable composition as described in claim 1, which does not contain a benzoxazole-based fluorescent brightening agent.

4. The electron beam curable composition according to claim 1 , wherein the (meth)acrylate compound (B) comprises an amine-modified (meth)acrylate.

5. The electron beam curable composition according to claim 1 , wherein the (meth)acrylate compound (B) comprises a polyester (meth)acrylate.

6. 2. The electron beam curable composition according to claim 1, wherein a total content of the resin (A), the (meth)acrylate compound (B), and the pigment (C) is 60 to 90 mass% with respect to a total mass of the composition.

7. The electron beam curable composition according to claim 1 , which is substantially free of a photopolymerization initiator.

8. The electron beam curable composition according to claim 1 , which is substantially free of organic solvents.

9. 2. The electron beam curable composition according to claim 1, which is substantially free of polytetrafluoroethylene wax.

10. A laminate comprising a substrate and a cured product of the electron beam curable composition according to any one of claims 1 to 9.

11. The laminate according to claim 10, wherein the substrate is a film or paper.

12. A method for producing a laminate, comprising: applying the electron beam curable composition according to any one of claims 1 to 9 onto a substrate to form a coating film; and irradiating the coating film with an electron beam under conditions of an acceleration voltage of 40 to 120 kV and an exposure dose of 10 to 60 kGy.

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