Electron beam curable printing ink composition

Abstract

The present invention provides an electron beam-curable printing ink composition for offset printing that can achieve both fluidity, storage stability, and curability of the ink, as well as suppression of odor in printed materials, abrasion resistance, tape adhesion, and lamination suitability. [Solution] An electron beam curable printing ink composition for offset printing, comprising (A) a polymer of an allyl monomer represented by the following general formula (1), (B) a (meth)acrylate resin, (C) a polyfunctional (meth)acrylate, and (D) a pigment, wherein the viscosity measured by a cone plate viscometer at 25°C and a shear rate of 100 / s is 1.0 Pa·s to 90.0 Pa·s. TIFF2026113545000013.tif27160 (In general formula (1), R 1 and R 2 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, X represents an n-valent group having a 4 to 8-membered anticyclic ring skeleton, and n is 2 or 3.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing printed materials, printed materials, and electron beam curable printing ink compositions. [Background technology]

[0002] In active energy ray-curing inks, diallyl phthalate resin (sometimes called "DAP resin" or "DAP resin") is used as one of the resin components. Although diallyl phthalate resin itself is generally considered harmless, its raw material, diallyl phthalate, is a type of phthalate ester and is therefore a chemical substance that raises concerns about its effects on the human body and the environment. For this reason, polymers of diallyl cyclohexanedicarboxylic acid, which are structurally similar, have been considered as alternative materials to diallyl phthalate resin in recent years.

[0003] Patent Document 1 discloses an active energy ray curable ink composition characterized by comprising a compound having an ethylenically unsaturated bond, component (A) which is a polymer of an allyl monomer having a specific structure, and component (B) which is a rosin-modified resin and / or a terpene monomer skeleton-containing resin.

[0004] Patent Document 2 discloses an active energy ray curable ink composition containing (A) a pigment, (B) an allyl resin, (C) an epoxy compound, (D) an oxetane compound, and (E) a photocationic polymerization initiator, characterized by the following (1) to (3). (1) The total amount of the ink composition contains (B) allyl resin in an amount of 3 to 25% by weight. (2) The ink composition contains a total of 30 to 65% by weight of (C) epoxy compound and (D) oxetane compound. (3) The weight ratio expressed as (C) epoxy compound / (D) oxetane compound is in the range of 1 to 5. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-121316 [Patent Document 2] Japanese Patent Publication No. 2023-161230 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in the prior art, including Patent Documents 1 and 2, there is still room for further improvement in achieving a balance between the required characteristics of ink, such as fluidity, storage stability, and curability, as well as odor suppression, abrasion resistance, tape adhesion, and lamination suitability of printed materials.

[0007] The present invention has been made in view of the above-described circumstances, and aims to provide a method for manufacturing printed materials, printed materials, and an electron beam-curable printing ink composition that can achieve both ink fluidity, storage stability, and curability, as well as odor suppression, abrasion resistance, tape adhesion, and lamination suitability of printed materials. [Means for solving the problem]

[0008] As a result of diligent research to achieve the above-mentioned objectives, the present inventors have found that an electron beam-curable printing ink composition containing (A) a polymer of an allyl monomer having a specific structure, (B) a (meth)acrylate resin, (C) a polyfunctional (meth)acrylate, and (D) a pigment is effective, and have completed the present invention.

[0009] In other words, the present invention is as follows. <1> A method for producing a printed material, comprising: a printing step of printing on a printing target using an electron beam curable printing ink composition containing (A) a polymer of an allyl monomer represented by the following general formula (1), (B) a (meth)acrylate resin, (C) a polyfunctional (meth)acrylate, and (D) a pigment; and a curing step of curing the printed electron beam curable printing ink composition by irradiating it with an electron beam under conditions where the acceleration voltage is 50 to 150 kV, the irradiation dose is 15 to 50 kGy, and the oxygen concentration is 300 ppm or less.

[0010] [ka]

[0011] (In general formula (1), R 1 and R 2 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, X represents an n-valent group having a 4 to 8-membered anticyclic ring skeleton, and n is 2 or 3. <2> The aforementioned component (B) is at least one selected from the group consisting of epoxy (meth)acrylate resin, polyester (meth)acrylate resin, and urethane (meth)acrylate resin. <1> This is a method for manufacturing printed materials as described above. <3> The content of component (A) in the electron beam curable printing ink composition is 3 to 30% by mass. <1> or <2> This is a method for manufacturing printed materials as described above. <4> The content of component (B) in the electron beam curable printing ink composition is 5 to 60% by mass. <1> or <2> This is a method for manufacturing printed materials as described above. <5> The content of component (C) in the electron beam curable printing ink composition is 5 to 60% by mass. <1> or <2> This is a method for manufacturing printed materials as described above. <6> The electron beam curable printing ink composition does not contain a polymerization initiator. <1> or <2> This is a method for manufacturing printed materials as described above. <7> The method for producing a printed matter according to <1> or <2>, wherein the electron beam-curable ink composition for printing is an offset printing ink composition. <8> The method for producing a printed matter according to <1> or <2>, wherein the electron beam-curable ink composition for printing is a front printing ink composition. <9> The method for producing a printed matter according to <1> or <2>, wherein the electron beam-curable ink composition for printing is a back printing ink composition. <10> A printed matter obtained by the method for producing a printed matter according to <1> or <2>. <11> (A) A polymer of an allyl monomer represented by the following general formula (1), (B) a (meth)acrylate resin, (C) a polyfunctional (meth)acrylate, and (D) a pigment, and is used for curing under curing conditions where the accelerating voltage is 50 to 150 kV, the irradiation dose is 15 to 50 kGy, and the oxygen concentration is 300 ppm or less. It is an electron beam-curable ink composition for printing.

Chemical formula

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a method for producing a printed matter, a printed matter, and an electron beam-curable ink composition for printing that can achieve both the fluidity, storage stability, and curability of the ink, and the suppression of the odor of the printed matter, abrasion resistance, tape adhesion, and laminating suitability.

Embodiments for Carrying Out the Invention

[0013] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). This embodiment is illustrative for explaining the present invention and is not intended to limit the present invention to the following content. The present invention can be implemented by modifying it as appropriate within the scope of its gist.

[0014] Furthermore, unless otherwise specified in this specification, "(meth)acrylate" encompasses both acrylate and methacrylate. For example, "(meth)acrylate" means acrylate, methacrylate, or both. The same applies to other similar terms such as "(meth)acrylic."

[0015] <Manufacturing methods for printed materials>

[0016] The method for manufacturing printed materials according to this embodiment includes a printing step of printing on a printing target using an electron beam-curable printing ink composition containing (A) a polymer of an allyl monomer represented by the following general formula (1), (B) a (meth)acrylate resin, (C) a polyfunctional (meth)acrylate, and (D) a pigment, and a curing step of curing the printed electron beam-curable printing ink composition by irradiating it with an electron beam under conditions where the acceleration voltage is 50 to 150 kV, the irradiation dose is 15 to 50 kGy, and the oxygen concentration is 300 ppm or less. According to this manufacturing method, it is possible to achieve at least the fluidity, storage stability, and curability of the ink, as well as the suppression of odor, abrasion resistance, tape adhesion, and lamination suitability of the printed material. The following describes each component and condition.

[0017] [ka]

[0018] (In general formula (1), R 1 and R 2 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, X represents an n-valent group having a 4 to 8-membered anticyclic ring skeleton, and n is 2 or 3.

[0019] <Electron beam curable printing ink composition>

[0020] The electron beam curable printing ink composition used in the method of manufacturing printed materials according to this embodiment (hereinafter sometimes simply referred to as "ink composition") is an electron beam curable printing ink composition containing (A) a polymer of an allyl monomer represented by the above general formula (1), (B) a (meth)acrylate resin, (C) a polyfunctional (meth)acrylate, and (D) a pigment.

[0021] Electron beam curable printing ink compositions possess the ability to harden upon irradiation with active energy rays such as ultraviolet rays or electron beams. As described later, these electron beam curable printing ink compositions contain compounds with ethylenically unsaturated bonds (e.g., monomers and oligomers), and hardening occurs when radicals generated in the ink composition upon irradiation with active energy rays increase the molecular weight of the compounds with ethylenically unsaturated bonds. Therefore, when an active energy ray is irradiated onto an ink composition that is sticky on the surface of a printed material immediately after printing, the ink composition instantly hardens to form a film and becomes dry (tack-free). From this viewpoint, electron beam curable printing ink compositions can achieve the desired effects even without containing polymerization initiators such as photopolymerization initiators (however, the effects of this embodiment are not limited to these).

[0022] The electron beam curable printing ink composition contains the above-mentioned components (A), (B), (C), and (D), and therefore, at least for the ink, it exhibits excellent fluidity, storage stability, and curability, and for printed materials using it, it exhibits excellent odor suppression, abrasion resistance, tape adhesion, and lamination suitability. Thus, the electron beam curable printing ink composition has at least the above-mentioned advantages regardless of the printing method, and also has excellent ink water-to-weight suitability and density stability, making it suitable as an ink composition for offset printing (for example, an offset printing ink composition, an electron beam curable offset printing ink composition, etc.). Details of these will be described later.

[0023] <(A) Polymer of allyl monomer>

[0024] The electron beam curable printing ink composition contains a component (A) which is a polymer of an allyl monomer represented by the following general formula (1). This polymer is obtained by polymerizing the allyl monomer represented by the following general formula (1) by means such as radical polymerization. However, a completely polymerized product may be used as an inert resin which is a binder, or a product in which the polymerization reaction is stopped at about 50% to 80% to leave unreacted unsaturated bonds may be used as a curable component.

[0025] [Chemical formula]

[0026] In general formula (1), R 1 and R 2 are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. In this specification, "each independently" means that each is independently determined without relation to each other, and they may be the same as each other or different from each other. Examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, etc. As a preferred embodiment, it can be mentioned that both R 1 and R 2 are hydrogen atoms, but it is not particularly limited.

[0027] In general formula (1), n is 2 or 3, and X is an n-valent group having an aliphatic ring skeleton of 4 to 8 members. The "n-valent group having an aliphatic ring skeleton of 4 to 8 members" means an n-valent group in which bonding hands to other groups occur from n carbon atoms among the carbon atoms constituting the aliphatic ring having 4 to 8 carbon atoms. X may have an aliphatic ring skeleton and may also contain other skeletons, but those consisting of an aliphatic ring skeleton are preferred. Further, as the aliphatic ring of X, cycloalkane or cycloalkene having 4 to 8 carbon atoms is preferred. In addition, X may be crosslinked in the molecule, and examples of X crosslinked in the molecule include adamantane, norbornene, norbornane, etc.

[0028] More specifically, X is preferably a divalent group represented by one of the following general formulas. In this case, n in general formula (1) is 2.

[0029] [ka]

[0030] Among the X represented by the above general formula, the 1,2-cyclohexalene group is preferred. In this case, the 1st and 2nd positions of cyclohexane are substituted with the group represented by the parenthetical part of general formula (1).

[0031] Suitable examples of allyl monomers represented by general formula (1) include 1,2-cyclohexanedicarboxylate diallyl, 1,3-cyclohexanedicarboxylate diallyl, 1,4-cyclohexanedicarboxylate diallyl, 4-cyclohexene-1,2-dicarboxylate diallyl, and 2-cyclohexene-1,2-dicarboxylate diallyl. Among these, 1,2-cyclohexanedicarboxylate diallyl, 4-cyclohexene-1,2-dicarboxylate diallyl, and 1,4-cyclohexanedicarboxylate diallyl are more preferred, and 1,2-cyclohexanedicarboxylate diallyl is even more preferred.

[0032] Allyl monomers represented by general formula (1) consist of a cycloalkane or cycloalkene having 4 to 8 carbon atoms and having 2 or 3 carboxyl groups, and a substituent R 1 and R 2 It is obtained by dehydration condensation and esterification with an allyl alcohol having substituent R. 1 and R 2 As previously mentioned, it is preferable that both are hydrogen atoms.

[0033] Furthermore, to obtain a polymer by polymerizing an allyl monomer represented by general formula (1), the allyl monomer can be polymerized using a radical polymerization initiator. Examples of such radical polymerization initiators include azo initiators such as azobisisobutyronitrile and dimethyl 2,2'-azobisisobutyrate; peroxide initiators such as ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, peroxyesters, and benzoyl peroxides; acetophenone-based initiators such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 1-hydroxycyclohexylphenyl ketone; benzoin-based initiators such as benzoin and benzoin ethyl ether; benzophenone-based initiators such as benzophenone; phosphorus-based initiators such as acylphosphine oxide; sulfur-based initiators such as thioxanthone; and benzyl-based photopolymerization initiators such as benzyl and 9,10-phenanthrenequinone. Furthermore, the radical polymerization initiator may be used alone or in combination of two or more types.

[0034] The amount of radical polymerization initiator is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 0.001 to 3 parts by mass, per 100 parts by mass of the allyl monomer represented by general formula (1). The reaction temperature during polymerization is not particularly limited, but is usually around 60 to 240°C. The reaction time is typically around 0.1 to 100 hours.

[0035] When polymerizing allyl monomers represented by general formula (1) to obtain polymers, a homopolymer using a single allyl monomer may be used, or a copolymer combining multiple allyl monomers or other monomers may be used. In the copolymer, other monomers copolymerizable with the above allyl monomers are not particularly limited, but examples include 3-methyl-hexahydro-1,2-diallyl phthalate, 4-methyl-hexahydro-1,2-diallyl phthalate, 3-methyl-1,2,3,6-tetrahydro-1,2-diallyl phthalate, and 4-methyl-1,2,3,6-tetrahydro-1,2-diallyl phthalate. A preferred embodiment in this example is a homopolymer of diallyl 1,2-cyclohexanedicarboxylic acid, but is not particularly limited.

[0036] The weight-average molecular weight of the polymer is not particularly limited, but is preferably between 2,000 and 300,000. The lower limit is more preferably 5,000 or more, and even more preferably 10,000 or more. The upper limit is more preferably 200,000 or less, even more preferably 150,000 or less, and even more preferably 140,000 or less. Unless otherwise specified, the weight-average molecular weight is the weight-average molecular weight (M) on a polystyrene basis, obtained by gel permeation chromatography (GPC) analysis. w ) refers to.

[0037] The polymer used may be one synthesized as described above, or a commercially available product may be used. An example of such a commercially available product is one manufactured by Osaka Soda Co., Ltd.

[0038] (A) Component may be used alone or in combination of two or more components.

[0039] The content of component (A) relative to the total electron beam curable printing ink composition is not particularly limited, but is preferably 3 to 30% by mass. The lower limit is more preferably 5% by mass or more, and even more preferably 10% by mass or more. The upper limit is more preferably 25% by mass or less, and even more preferably 15% by mass or less. If the electron beam curable printing ink composition in this embodiment contains a solvent, the above content is preferably the content when the total solid content is taken as 100% by mass.

[0040] <(B)(meth)acrylate resin>

[0041] Electron beam curable printing ink compositions contain (meth)acrylate resins. Examples of (meth)acrylate resins include resins having a (meth)acrylate skeleton with one or more functional groups selected from the group consisting of epoxy groups, ester groups, ether groups, and urethane groups. Specific examples include epoxy (meth)acrylate resins, polyester (meth)acrylate resins, urethane (meth)acrylate resins, and polyether (meth)acrylate resins.

[0042] Among these, it is preferable that component (B) is at least one selected from the group consisting of epoxy (meth)acrylate resin, polyester (meth)acrylate resin, and urethane (meth)acrylate resin. By using these, the adhesion of the ink coating and the lamination suitability of the printed material can be further improved.

[0043] Epoxy (meth)acrylate resins can be, for example, aromatic (meth)acrylate resins having a bisphenol skeleton, or aliphatic (meth)acrylate resins having a hydrogenated bisphenol skeleton. Commercially available products may also be used.

[0044] Polyester (meth)acrylate resins can be, for example, aliphatic polyester (meth)acrylates or aromatic polyester (meth)acrylates. Commercially available products may also be used.

[0045] Examples of urethane (meth)acrylate resins that can be used include polyester urethane (meth)acrylate, polyether urethane (meth)acrylate, and polycarbonate urethane (meth)acrylate. Commercially available products of these may also be used.

[0046] (B) Component may be used alone or in combination of two or more components.

[0047] The content of component (B) relative to the total electron beam curable printing ink composition is not particularly limited, but is preferably 5 to 60% by mass. The lower limit is more preferably 10% by mass or more, and even more preferably 15% by mass or more. The upper limit is more preferably 50% by mass or less, and even more preferably 40% by mass or less. If the electron beam curable printing ink composition in this embodiment contains a solvent, the above content is preferably the content when the total solid content is considered to be 100% by mass.

[0048] (C) Multifunctional (meth)acrylate

[0049] The electron beam curable printing ink composition contains (C) a polyfunctional (meth)acrylate. The polyfunctional (meth)acrylate compound can enhance the electron beam curability of the ink composition. Polyfunctionality refers to the number of (meth)acrylate groups contained in one molecule, and it is preferable that it be 2- to 6-functional.

[0050] (C) Specific examples of component (C) are not particularly limited, but include, for example, 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol Di(meth)acrylates of dihydric alcohols such as glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate; di(meth)acrylate of polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, tris(2-hydroxyethyl) isocyanurate di(meth)acrylate, and diols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol. meth)acrylate; di(meth)acrylate of diols obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A; poly(meth)acrylate of trivalent or higher polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dipentaerythritol poly(meth)acrylate; 1 mole of glycerin Poly(meth)acrylates of polyoxyalkylene polyols such as tri(meth)acrylates of triols obtained by adding 3 moles or more of ethylene oxide or propylene oxide to trimethylolpropane, di(meth)acrylates of triols obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane, and di(meth)acrylates of diols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A; vegetable oil (e.g., soybean oil) modified epoxy acrylates;Examples include urethane acrylate.

[0051] Among these, alkylene oxide-modified trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, alkylene oxide-modified glycerin (meth)acrylate, soybean oil-modified acrylate, urethane acrylate, etc. are preferred; ditrimethylolpropane tetra(meth)acrylate, tri(meth)acrylate of a 3-mol ethylene oxide adduct of trimethylolpropane, tri(meth)acrylate of a 6-mol ethylene oxide adduct of trimethylolpropane, tri(meth)acrylate of a 3-mol propylene oxide adduct of trimethylolpropane, tri(meth)acrylate of a 3-mol propylene oxide adduct of glycerin, dipentaerythritol hexaacrylate, etc. are more preferred.

[0052] (C) Component may be used alone or in combination of two or more types.

[0053] Component (C) is preferably a compound with a low glass transition temperature (for example, preferably 100°C or lower, more preferably 60°C or lower). A component (C) with a low glass transition temperature can improve the lamination suitability of the ink composition. Specific examples of (meth)acrylate compounds with a low glass transition temperature include, but are not limited to, di or tri(meth)acrylates of triols obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane. Furthermore, when two or more types of (C) components are used in combination, for example, it is preferable that 50% by mass or more of component (C) is a compound with a low glass transition temperature, and it is more preferable that 60% by mass or more of component (C) is a compound with a low glass transition temperature.

[0054] The content of component (C) relative to the entire electron beam curable printing ink composition is not particularly limited, but is preferably 5 to 60% by mass. The lower limit is more preferably 10% by mass or more, and even more preferably 20% by mass or more. The upper limit is more preferably 55% by mass or less, and even more preferably 50% by mass or less. If the electron beam curable printing ink composition in this embodiment contains a solvent, the above content is preferably the content when the total solid content is considered to be 100% by mass.

[0055] <(D) Pigment>

[0056] The electron beam curable printing ink composition contains (D) a pigment. The type of (D) pigment is not particularly limited, but examples include inorganic pigments and organic pigments. Specific examples of inorganic pigments include coloring pigments such as carbon black, graphite, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, and titanium dioxide (including achromatic coloring pigments such as white and black); and extender pigments such as graphite, zinc, lime carbonate powder, calcium carbonate, gypsum, clay, silica (silicon dioxide), diatomaceous earth, talc, kaolin, alumina white, barium sulfate, aluminum stearate, magnesium carbonate, magnesium silicate, barite powder, and glass beads. Specific examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments.

[0057] (D) Component may be used alone or in combination of two or more components.

[0058] Furthermore, extender pigments can more effectively adjust the rheological properties of the ink composition. In addition, by localizing on the surface (outer surface) of the cured film formed by the ink composition, extender pigments can be expected to effectively prevent sticking of printed materials, etc. (However, the effects and benefits of this embodiment are not limited to these).

[0059] Furthermore, one preferred example of an extender pigment is one that contains at least (D-1) calcium carbonate, magnesium carbonate, or magnesium silicate in combination with (D-2) silica (silicon dioxide). Such a combination, in conjunction with other components, can more effectively suppress the stringiness (tendency to string) of the ink composition. The content ratio (mass ratio) of component (D-1) and component (D-2) is not particularly limited, but is preferably 10:1 to 1:1, more preferably 10:1 to 2:1, even more preferably 10:1 to 4:1, and even more preferably 10:1 to 6:1.

[0060] The content of the extender pigment in component (D) relative to the entire electron beam curable printing ink composition is not particularly limited, but is preferably 0.1 to 10% by mass. The lower limit is more preferably 1% by mass or more, and even more preferably 2% by mass or more. The upper limit is more preferably 8% by mass or less, and even more preferably 6% by mass or less. If the electron beam curable printing ink composition in this embodiment contains a solvent, the above content is preferably the content when the total solid content is 100% by mass.

[0061] <(E) Other ingredients, etc.>

[0062] Electron beam curable printing ink compositions may optionally contain other components besides those mentioned above, as long as their action and effect can be obtained. Examples of other components include colorants other than component (D), pigment dispersants, waxes, polymerization inhibitors, surfactants, solvents, etc.

[0063] Other colorants besides component (D) include, for example, dyes. Examples of dyes include basic reaction type lakes, acid dye type lakes, and nitro pigments.

[0064] Examples of pigment dispersants include polymer-based pigment dispersants. The polymer-based pigment dispersant is preferably a pigment dispersant containing basic groups. Specific examples of pigment dispersants containing basic groups include polymer-based pigment dispersants such as basic group-containing polyester pigment dispersants, basic group-containing acrylic pigment dispersants, basic group-containing urethane pigment dispersants, and basic group-containing carbodiimide pigment dispersants; and anionic surfactants. While the polymer-based pigment dispersant is not particularly limited, a linear polymer having a pigment-affinity portion consisting of basic groups at least at the ends of the main chain (one or both ends) can be used, either in a block structure or a graft structure.

[0065] Examples of waxes include animal and plant-based waxes such as beeswax, lanolin wax, whale wax, candelilla wax, carnauba wax, rice wax, wood wax, and jojoba oil; mineral and petroleum-based waxes such as montane wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and petrolatum; synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene wax, oxidized polyethylene wax, and oxidized polypropylene wax; fluororesin-based waxes such as polytetrafluoroethylene wax; mixtures of polytetrafluoroethylene wax and polyethylene wax; modified waxes such as montane wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives; hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives; and polytetrafluoroethylene wax.

[0066] Polymerization inhibitors can effectively prevent unintended polymerization reactions from occurring during storage of the ink composition and can effectively suppress the thickening of the ink composition. Examples of polymerization inhibitors include phenolic compounds (including quinone compounds) such as dibutylhydroxytoluene (BHT), tocopherol acetate, nitrosamine compounds, benzotriazole, and hindered amines. Among these, phenolic compounds such as dibutylhydroxytoluene are preferred. The content of the polymerization inhibitor in the ink composition can be appropriately set depending on the type of polymerization inhibitor, but for example, in the case of phenolic compounds such as dibutylhydroxytoluene (BHT), it may be about 0.3 to 2.0 parts by mass when the total curable component is 100 parts by mass.

[0067] Examples of surfactants include nonionic surfactants, cationic surfactants, anionic surfactants, and betaine surfactants. Specific examples of surfactants include silicone-based surfactants such as polyether-modified silicone oil, polyester-modified polydimethylsiloxane, and polyester-modified methylalkylpolysiloxane, as well as fluorine-based surfactants and acetylene-based surfactants.

[0068] Electron beam curable printing ink compositions can be cured by irradiation with an electron beam even without containing a polymerization initiator. Therefore, the ink composition may or may not contain a polymerization initiator, but it is preferable that it does not. Specific examples of such polymerization initiators include those other than the components mentioned above, such as acylphosphine oxide compounds, thioxanthone compounds, aromatic ketones, aromatic onium salt compounds, organic peroxides, thio compounds (such as compounds containing a thiophenyl group), α-aminoalkylphenone compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds.

[0069] The electron beam curable printing ink composition may or may not contain a solvent such as water or an organic solvent. The solvent may be present in small amounts, for example, 3% by mass or less relative to the mass of the ink composition. Unless otherwise specified, when the electron beam curable printing ink composition in this embodiment contains a solvent, the numerical values ​​of the content described herein are preferably the content when the total solid content is considered to be 100% by mass.

[0070] The viscosity of the electron beam-curable printing ink composition is preferably 100.0 Pa·s or less, and more preferably between 1.0 Pa·s and 90.0 Pa·s. This viscosity may be the viscosity measured using a cone-plate viscometer at 25°C and a shear rate of 100 / s. By having this viscosity within the above numerical range, the fluidity and transferability of the ink composition are further improved, which is expected to improve the stability of the ink composition supplied to the roller in offset printing and thus improve printability. Furthermore, by having this viscosity within the above numerical range, the leveling of the ink composition transferred to the printing target (substrate, etc.) is further improved, which is expected to more effectively suppress quality defects such as gloss degradation. Moreover, by having the viscosity of the ink composition within the above range, it becomes easier to control the tack value of the ink to a suitable value, which is expected to effectively suppress transfer defects to the printing target and ensure stable printability.

[0071] Electron beam curable printing ink compositions have the property of curing when irradiated with an electron beam (curability). From this viewpoint, it is preferable that the electron beam curable printing ink composition contains (A) a polymer of an allyl monomer represented by the above general formula (1), (B) a (meth)acrylate resin, (C) a polyfunctional (meth)acrylate, and (D) a pigment, and is used for curing under curing conditions where the acceleration voltage is 50 to 150 kV, the irradiation dose is 15 to 50 kGy, and the oxygen concentration is 300 ppm or less. The degree of curability is not particularly limited, but for example, when formed into a coating film, it is preferable that it is completely cured at an irradiation dose of 20 to 40 kGy.

[0072] <Method for producing electron beam-curable printing ink composition>

[0073] Electron beam curable printing ink compositions can be obtained by a process of mixing components (A) to (D) described above and other components (such as component (E)) as needed. For example, it can be obtained by dissolving a polymer of (A) allyl monomers or a polymer of (B) (meth)acrylate in (C) polyfunctional (meth)acrylate, dispersing a pigment (D), and mixing in other arbitrary components (such as component (E)). The mixing methods are not particularly limited.

[0074] <Printing process, curing process, printed matter, etc.>

[0075] In the method for manufacturing printed materials according to this embodiment, a printing step is performed in which the ink composition is printed on the object to be printed, followed by a curing step in which the printed electron beam-curable printing ink composition is cured by irradiating it with an electron beam. In the printing step, a suitable method can be appropriately selected depending on the materials used and the application, for example, a method of applying the electron beam-curable printing ink composition to the object to be printed can be adopted. Furthermore, the printing method in the printing step is not particularly limited, and various methods described later can be adopted. In the curing step, the electron beam is irradiated under conditions where the acceleration voltage is 50 to 150 kV, the irradiation dose is 15 to 50 kGy, and the oxygen concentration is 300 ppm or less. The material of the object to be printed (substrate) is not particularly limited as long as it is a material on which the ink composition can be electron beam cured, and can be appropriately selected according to the application, but by keeping the acceleration voltage, irradiation dose, and oxygen concentration within the above ranges, the various advantages of this embodiment described above can be effectively realized.

[0076] As mentioned above, the acceleration voltage may be between 50 and 150 kV, but the lower limit is preferably 60 kV or higher, more preferably 70 kV or higher, and even more preferably 80 kV or higher. The upper limit is preferably 140 kV or lower, more preferably 130 kV or lower, and even more preferably 110 kV or lower.

[0077] As mentioned above, the irradiation dose should be between 15 and 50 kGy, but the lower limit is preferably 20 kGy or higher. Furthermore, the upper limit is preferably 40 kGy or lower.

[0078] As mentioned above, the oxygen concentration should be 300 ppm or less, but the upper limit is preferably 250 ppm or less, more preferably 200 ppm or less, and even more preferably 150 ppm or less. The lower limit is preferably 50 ppm or more, more preferably 70 ppm or more, and even more preferably 80 ppm or less.

[0079] Furthermore, the method for manufacturing printed materials according to this embodiment is excellent in terms of water-to-weight suitability and density stability, and is therefore suitable for use in offset printing. From this viewpoint, the method for manufacturing printed materials according to this embodiment is preferably offset printing. For example, a manufacturing method is exemplified that includes a step of offset printing an electron beam-curable printing ink composition onto a printing target (offset printing step) and a step of curing the offset-printed electron beam-curable printing ink composition by irradiating it with an electron beam (curing step). The printing method of this embodiment will be described exemplarily below, with offset printing as one example, but it goes without saying that it is not limited to the following embodiments.

[0080] The printing target in the offset printing process is not particularly limited and can include substrates made of resin, metal, or paper. Specific examples of metals used in metal substrates include aluminum, zinc, copper, iron, and tin. Specific examples of paper substrates include synthetic paper, art paper, coated paper, cast paper, newsprint, resin-laminated paper, metal-metallized paper, and metal oxide-metallized paper.

[0081] Considering the effects and benefits of this embodiment, such as improved adhesion to the printing target and lamination suitability, a resin substrate, particularly a resin film, is sometimes preferable. The type of resin constituting the resin substrate is not particularly limited, but examples include films or sheets of polyester resin (e.g., polyethylene terephthalate), acrylic resin, vinyl chloride resin, vinylidene chloride resin, polyvinyl alcohol, polyethylene, polypropylene, polyacrylonitrile, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, ethylene methacrylic acid copolymer, nylon, polylactic acid, polycarbonate, cellophane, aluminum foil, and various other resins that have been conventionally used as printing targets (substrates to be printed). The resin film may be subjected to stretching (uniaxial stretching, biaxial stretching, etc.).

[0082] The offset printing process can be carried out in accordance with known printing methods, but examples include a method that includes (a) a step of supplying the electron beam curable printing ink composition and dampening water according to this embodiment to a printing plate, (b) a step of transferring the ink composition supplied to the plate to a blanket (offset step), and (c) a step of fixing the ink composition transferred to the blanket to the object to be printed (set step).

[0083] The dampening solution supplied to the printing plate is a solution primarily composed of water, and may contain any additional components. Specific examples of these additional components include pH adjusters, water-soluble organic solvents, chelate compounds, and water-soluble polymers.

[0084] In step a, which involves supplying the ink composition and dampening water to the plate, for example, the ink composition can be supplied to the plate wrapped around the plate cylinder by an ink roller, and the dampening water by a water supply roller. The plate usually has areas to which the ink composition adheres (lipophilic image areas) and areas to which the dampening water adheres (hydrophilic non-image areas). The ink composition adheres to the image areas of the plate, but the ink composition that adheres may be an emulsion of the ink composition and dampening water (water-in-oil emulsion).

[0085] The ink composition (or emulsion with dampening solution) adhering to the image area of ​​the plate is transferred to the blanket (step b). The dampening solution adhering to the non-image area of ​​the plate is collected without being transferred to the blanket cylinder. Furthermore, the ink composition (or emulsion with dampening solution) transferred to the blanket is usually pressed against the printing target (substrate, etc.) by the impression cylinder and fixed to the printing target to form a coating (step c).

[0086] The coating film formed on the printing target by offset printing is hardened by irradiation with an electron beam to form a hardened film, which then fixes as an image. In the case of offset printing, the acceleration voltage of the electron beam is preferably in the range of 80 to 150 kV, and more preferably in the range of 80 to 110 kV, from the viewpoint of effectively suppressing the penetration of the electron beam into the printing target and suppressing damage to the printing target. Furthermore, the irradiation dose of the electron beam is preferably in the range of 20 to 40 kGy from the viewpoint of reliably hardening the coating film and suppressing poor adhesion to the substrate by excessive hardening. It is also preferable to appropriately set the upper limits of these parameters from the viewpoint of effectively preventing damage to the printing target (substrate to be printed, etc.) due to high irradiation doses and high acceleration voltages.

[0087] Furthermore, according to this embodiment, printed materials can also be obtained by printing using the method described above. The various conditions of the printing process can be appropriately selected from the various conditions described above. The printed materials obtained by the manufacturing method according to this embodiment are excellent in terms of odor suppression, abrasion resistance, tape adhesion, and lamination suitability.

[0088] <Applications of ink compositions and printed materials>

[0089] The method for manufacturing a printed material according to this embodiment involves printing and curing on a printing target to form a printed layer and thereby produce a printed material. The method for manufacturing a printed material according to this embodiment may be used to produce a reverse-printed printed material (reverse-printing ink composition), or to produce a front-printed printed material (front-printing ink composition), or to produce other types of printed materials. In the case of front-printing, for example, a manufacturing method may include a step of front-printing an electron beam-curable printing ink composition onto a printing target (front-printing step), and a step of curing the front-printed electron beam-curable printing ink composition by irradiating it with an electron beam (curing step). In the case of reverse-printing, for example, a manufacturing method may include a step of back-printing an electron beam-curable printing ink composition onto a printing target (reverse-printing step), and a step of curing the back-printed electron beam-curable printing ink composition by irradiating it with an electron beam (curing step).

[0090] In the case of surface printing (or surface printing ink composition), the printed layer is exposed on the surface of the printed material, so high adhesion between the substrate to be printed and the printed layer is required. In this regard, the electron beam curable printing ink composition according to this embodiment has excellent adhesion, so the printed layer (printed portion) obtained from this ink composition has high adhesion to the substrate to be printed and can be suitably used in surface printing.

[0091] In the case of reverse printing (or reverse printing ink composition), the printed material is generally obtained as a laminate by laminating a laminate layer that covers the printed layer. Therefore, printed materials obtained by reverse printing are required to have high lamination suitability (the laminate layer is not easily peeled off). In this respect, the method for manufacturing printed materials according to this embodiment is excellent in terms of lamination suitability, etc., so the printed layer obtained from the ink composition can be strongly bonded to the laminate layer via an adhesive, etc., and is therefore suitable for use in reverse printing.

[0092] In other words, a laminate film (a laminated film comprising, in this order, a base film, a base material to be printed on, a cured product of the electron beam-curable printing ink composition according to this embodiment, an adhesive layer, and a sealant layer) can be obtained by fixing the cured product of the electron beam-curable printing ink composition to a base film, a base material to be printed on, an adhesive layer, and a sealant layer.

[0093] The substrate film, which is the substrate to be printed on, is preferably made of resin, but is not particularly limited and can be selected according to the intended use of the resulting laminate film. The adhesive layer is a cured product of an adhesive composition, but the composition of the adhesive composition is not particularly limited. The sealant layer, which is arranged to cover the adhesive layer, is preferably made of resin, for example, polyolefin, but can be selected according to the intended use of the laminate film.

[0094] The sealant layer may be formed by dry lamination, solvent-free lamination, or extrusion lamination. In order to effectively exhibit the effects of the electron beam-curable printing ink composition according to this embodiment (high adhesion to the substrate to be printed and high lamination suitability), it is sometimes preferable that the sealant layer be formed by the dry lamination method.

[0095] The laminate film obtained in this manner has the advantage of having high adhesion between the substrate to be printed and the cured layer of the ink composition, as well as high adhesion between the cured layer of the ink composition and the adhesive layer, thus easily ensuring sufficient lamination suitability. Furthermore, the resulting laminate film can be used for any application, for example, in a wide range of lamination applications such as food packaging and food preservation packaging.

[0096] As described above, the method for manufacturing printed materials, the printed materials, and the electron beam-curable printing ink composition according to this embodiment can achieve a balance of ink fluidity, storage stability, and curability, as well as odor suppression, abrasion resistance, tape adhesion, and lamination suitability of the printed materials. These advantages are expected to be evident in a wide range of printing methods. In addition, because they also have excellent water-to-weight suitability and density stability, they can be suitably used in offset printing, which allows for quick, easy, and large-volume printing of clear prints.

[0097] Furthermore, the method for manufacturing printed materials, the printed materials, and the electron beam-curable printing ink composition according to this embodiment can be suitably used for both front-side printing and back-side printing. For example, in the case of package printing, in the case of front-side printing, the printing is done on the front side of the package (bag), and according to the electron beam-curable printing ink composition according to this embodiment, it is expected that problems such as the ink rubbing off can be effectively suppressed.

[0098] Furthermore, in the case of reverse printing, the printing is done from the back of a transparent material such as a bag, and is covered by a laminate layer. The printed layer is then visible to the user from the front through the transparent material. In this respect, the electron beam curable printing ink composition according to this embodiment has excellent lamination properties, so even if the contents are food or other items where safety is required, the lamination effect is sufficiently maintained, and it can be expected that the contents will be stored safely and hygienically for a long period of time without the ink components contaminating the contents.

[0099] As described above, the method for manufacturing printed materials, the printed materials, and the electron beam-curable printing ink composition according to this embodiment can be suitably used in a wide range of printing methods, but they are particularly advantageous in offset printing. They are also suitable for printing food packaging and food preservation packaging. The term "food" as used herein is not limited to its shape or contents, and can include solid, semi-solid, fluid, and liquid foods as preservation targets. [Examples]

[0100] The present invention will be described in more detail below with reference to examples, but these examples should not be interpreted as limiting the scope of the present invention. The numerical values ​​of the formulations shown in each table are in parts by mass.

[0101] <Preparation of electron beam curable printing ink composition>

[0102] First, the material components used to prepare the electron beam-curable printing ink compositions for each example and comparative example are shown below.

[0103] (resin) • AD-032: A homopolymer of diallyl 1,2-cyclohexanedicarboxylate (see formula (i) below) (trade name "RADPAR-AD032", manufactured by Osaka Soda Co., Ltd., non-phthalate type allyl resin)

[0104] [ka]

[0105] • A-DAP: Homopolymer of diallyl phthalate (product name "Daiso DAP A", manufactured by Osaka Soda Co., Ltd.) ·VS-1063: Polystyrene (product name "VS-1063", polystyrene, weight-average molecular weight (M) w )5,500, manufactured by Seiko PMC) • ISODAP: Homopolymer of diallyl isophthalate (product name "Daiso ISODAP", manufactured by Osaka Soda Co., Ltd.)

[0106] (Polymerizable compound (polyfunctional)) • M410: Ditrimethylolpropanetetraacrylate (product name "MIRAMER M410", manufactured by Miwon) • M3130: Triacrylate of the 3-mol ethylene oxide adduct of trimethylolpropane (product name "MIRAMER M3130", manufactured by Miwon) • M3160: Triacrylate of the 6-mol ethylene oxide adduct of trimethylolpropane (product name "MIRAMER M3160", manufactured by Miwon) • M360: Triacrylate of the 3-mol propylene oxide adduct of trimethylolpropane (product name "MIRAMER M360", manufactured by Miwon) • M320: Triacrylate of a 3-mol adduct of glycerin with propylene oxide (product name "MIRAMER M320", manufactured by Miwon) • M600: Dipentaerythritol hexaacrylate (product name "MIRAMER M600", manufactured by Miwon)

[0107] (Polymerizable compound (monofunctional)) • IBXA: Isobornyl acrylate (product name "IBXA", manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0108] ((meth)acrylate resin) • PE210: Bisphenol A skeleton-containing epoxy diacrylate (product name "MIRAMER PE210", manufactured by Miwon) • 623-100: Bisphenol A skeleton-containing epoxy acrylate (product name "ETERCURE 623-100", manufactured by Eternsl Materials) • EBECRYL600: Aromatic epoxy acrylate (product name "EBECRYL600", manufactured by Daicel Ornex Co., Ltd.) • EBECRYL3700: Aromatic epoxy acrylate (product name "EBECRYL3700", manufactured by Daicel Ornex Co., Ltd.) • EBECRYL3702: Fatty acid-modified epoxy acrylate (product name "EBECRYL3702", manufactured by Daicel Ornex Co., Ltd.) • PE310: Soybean oil-modified epoxy acrylate (product name "MIRAMER PE310", manufactured by Miwon) • EBECRYL438: A mixture of 60 parts by mass of chlorinated polyester acrylate and 40 parts by mass of glycerin propoxy triacrylate (product name "EBECRYL438", manufactured by Daicel Ornex Co., Ltd.) • DR-U161: Aliphatic urethane acrylate (product name "ETERCURE DR-U161", manufactured by Eternsl Materials)

[0109] (Extender pigments) • T-DD: Calcium carbonate (product name "Hakuenka T-DD", manufactured by Shiraishi Calcium Co., Ltd.) • L-1: Talc (Product name "L-1", manufactured by Nippon Talc Co., Ltd.) • CP-102: Silica (Product name "Leoro Seal CP102", manufactured by Tokuyama Corporation)

[0110] (Other pigments) • MA-70: Carbon Black (Product name "MA-70", manufactured by Mitsubishi Chemical Corporation)

[0111] (Pigment dispersant) • Solspers 33000: Basic functional group-containing copolymer (amine value 43.0 mg KOH / g, acid value 27 mg KOH / g, active ingredient 100% by mass, manufactured by Lubrizol Nippon Co., Ltd.)

[0112] (wax) • MG: Synthetic wax (product name "S-394 MG", manufactured by Shamrock Technologies)

[0113] (Polymerization inhibitor) BHT: Dibutylhydroxytoluene

[0114] (film) • OPP: Stretched polypropylene film (product name "P2161", manufactured by Toyobo Co., Ltd.) • PE: Uniaxially oriented polyethylene film (manufactured by JINDAL Co., Ltd.) • OPA: Stretched nylon film (product name "Emblem ONM-15", manufactured by Unitika Corporation) • PET: Polyethylene terephthalate film (product name "E-5102", manufactured by Toyobo Co., Ltd.)

[0115] Each component was blended to achieve the composition shown in each table (mass %), and the mixture was kneaded in a three-roll mill to obtain the electron beam curable printing ink compositions (ink compositions) for each example and comparative example.

[0116] <Evaluation Method>

[0117] The electron beam-curable printing ink compositions (ink compositions) and printed materials of each example and comparative example were evaluated in the following manner.

[0118] (Assessment of liquidity) For each example and comparative example ink composition, the flow value was measured using a spread meter, and the fluidity was evaluated as a flow slope value. The flow slope value is calculated by subtracting the spread diameter measured in mm after 10 seconds from the spread diameter measured in mm after 100 seconds using a spread meter. A larger value indicates better fluidity. 5. The flow gradient value was 10 or greater. 4. The flow gradient value was between 5 and 10. 3: The flow gradient value was between 3 and 5. 2: The flow gradient value was between 1 and 3. 1: The flow gradient value was less than 1.

[0119] (Evaluation of storage stability) For each example and comparative example of ink composition, the viscosity was measured using an E-type viscometer (product name: RE100L viscometer, manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C and a rotor rotation speed of 20 rpm. Afterward, the compositions were stored at 25°C for 30 days in a static state, and the viscosity at 25°C was measured again using the same method as before storage. Storage stability was evaluated by calculating the percentage change in viscosity before and after storage using the following formula. Viscosity change rate (%) = ((Viscosity after storage - Viscosity before storage) / Viscosity before storage) × 100 5. The absolute value of the rate of change in viscosity was 3% or less. 3. The absolute value of the rate of change in viscosity was greater than 3% and less than or equal to 5%. 1: The absolute value of the rate of change in viscosity exceeded 5%.

[0120] (Evaluation of hardening properties) 0.1 mL of the ink composition for each example and comparative example was spread onto an OPP film using an RI color spreader (two-part roll, manufactured by Akira Seisakusho Co., Ltd.). Then, electron beam irradiation (EB irradiation device, irradiation conditions are as described in the "EB curing conditions" column of Tables 1 to 4) was repeated until the ink coating printed on the printed material was cured, and the number of passes was counted. Curing was determined when the ink did not adhere when the coating was rubbed with a cotton swab. It hardened with a 5:1 pass. It hardened with a 4:2 pass. It hardened with a 3:3 pass. It hardened in a 2:4 pass. It cured or did not cure after 1:5 passes or more.

[0121] (Evaluation of suitability for water width) First, unless otherwise specified, the printed materials were produced by printing on printing paper according to the following procedures and conditions. • Printing press: Komori Corporation, full-size, single-sided, four-color press • Print rotation speed: 12,000 sph • Printed version: Fujifilm Global Graphic Systems, XP-F (CTP version) AM175 lines • Printing paper: Nippon Paper Industries, OK Coat L

[0122] Printing was started with the dampening water supply dial set to 30, and after printing 10,000 sheets, the dampening water supply dial was reduced to 15 (the amount of dampening water supplied was reduced). The ink stain density (OD value) in the blank areas (non-image areas) of the printed materials obtained when the dial value was reduced was measured, and the suitability of the water width was evaluated according to the following criteria. 5: The ink stain density in the plain areas was less than 0.01. 4: The ink stain density in the plain areas was between 0.01 and less than 0.05. 3: The ink stain density in the plain areas was between 0.05 and less than 0.1. 2: The ink stain density in the plain areas was between 0.1 and less than 0.2. 1: The ink stain density in the plain areas was 0.2 or higher.

[0123] (Evaluation of concentration stability) Printed materials were prepared using the ink compositions of each example and comparative example under the same conditions as described in "(Evaluation of Water Width Suitability)" above. However, the dampening water supply amount was varied in 10% increments between 10% and 60% (increasing the dampening water supply amount), and the print density (OD value) of the image area of ​​the printed material obtained at each dampening water supply amount was measured. The dampening water supply amount represents the rotation speed (%) of the water source roller. The rate of decrease in print density (OD value) was then calculated using the following formula with the X-Rite spectrophotometer "eXact Advance".

[0124]

number

[0125] 5. The rate of decrease in concentration was 0%. 4. The rate of decrease in concentration was greater than 0% and less than or equal to 5%. 3. The rate of decrease in concentration was greater than 5% but less than or equal to 10%. 2: The rate of decrease in concentration was greater than 10% but less than or equal to 15%. 1: The rate of decrease in concentration exceeded 15%.

[0126] (Odor evaluation) 0.1 mL of the ink composition for each example and comparative example was spread onto an OPP film using an RI color spreader (two-roll type, manufactured by Akira Seisakusho Co., Ltd.). The printed material was then subjected to electron beam irradiation until the ink coating hardened, and the printed material was obtained. Except for the curing evaluation of Comparative Examples 14-16, the electron beam irradiation conditions were 90 kV acceleration voltage, 30 kGy irradiation dose, and 100 ppm oxygen concentration. In Comparative Examples 14-16, the curing evaluation was also performed under the conditions described in "EB Curing Conditions" in the table. Then, four panelists checked for the presence or absence of odor in the printed material using the OPP film as the substrate. 5: No one noticed any odor. 4 out of 1 people detected an odor. 3:2 people detected an odor. 2 out of 3 people noticed an odor. 1: Everyone noticed the odor.

[0127] (Evaluation of abrasion resistance) In the printed material using the above-mentioned OPP film as a base material, friction was applied 200 times with a 500g weight via a backing cloth (Kanakin No. 3), and the condition of the coating after this friction was visually observed. 5: No scratches were observed on the surface of the cured film. 4: Scratches were observed on the surface of the cured film, but no peeling was confirmed. 3: Less than half of the entire surface of the hardened film peeled off, revealing less than half of the underlying material. 2: More than half of the entire surface of the hardened film peeled off, revealing more than half of the underlying material. 1: The hardened film has completely peeled off.

[0128] (Preparation of cured products using films other than OPP as a base material) 0.1 mL of the ink composition for each example and comparative example was spread onto each film (PE, OPA, PET) other than OPP using an RI color spreader (2-roll type, manufactured by Akira Seisakusho Co., Ltd.). Then, electron beam irradiation was performed until the ink coating printed on the material hardened, and the printed material was obtained. The electron beam irradiation conditions were the same for all cases except for the curability evaluation of comparative examples 14-16: acceleration voltage 90 kV, irradiation dose 30 kGy, and oxygen concentration 100 ppm. In comparative examples 14-16, curing was also performed under the conditions described in "EB curing conditions" in the table.

[0129] (Tape adhesion) Cellophane tape (manufactured by Nichiban Co., Ltd., product name "Sellotape®") was applied to the cured coating surface of printed materials using each of the above films (OPP, PE, OPA, PET) as a base material, and then peeled off in one swift motion. The area of ​​the cured coating that was peeled off was evaluated on a 5-point scale according to the following criteria. Note that a smaller peeled area was evaluated as indicating better adhesion between the cured coating and the resin film. 5: It didn't peel off at all. 4. The amount of peeled hardened film was greater than 0% but less than or equal to 20% of the total area. 3: The amount of peeled hardened coating was between 20% and 50% of the total area. 2: The amount of peeled hardened film was between 50% and 75% of the total area. 1: The peeled-off hardened coating covered more than 75% of the surface area.

[0130] (Lamination suitability) First, apply 3.5 g / m² of adhesive (Mitsui Chemicals, "Takelac A969V / Takenate A-5") as a solid component to the cured coating surface of the printed material using each of the above films (OPP, PE, OPA, PET) as a base material. 2 The material was applied in the specified amount, and an unstretched polypropylene film (RM Tohcello Co., Ltd., "GLC", 40 μm thick) was laminated using a dry laminating machine. Then, the tensile strength of each laminate was determined using a tensile testing machine (Yasuda Seiki Seisakusho Co., Ltd.) under the conditions of a measurement temperature of 25°C and a tensile speed of 200 mm / min. The lamination suitability was then evaluated based on the following criteria. 5. The peel strength was 1.5 N / 15 mm or higher. 4. The peel strength was 1.0 N / 15 mm or more and less than 1.5 N / 15 mm. 3. The peel strength was between 0.5 N / 15 mm and less than 1.0 N / 15 mm. 2: The peel strength was between 0.1 N / 15 mm and less than 0.5 N / 15 mm. 1: The peel strength was less than 0.1 N / 15 mm.

[0131] The composition and evaluation results of the ink compositions for each example and comparative example are shown in Tables 1 to 4.

[0132] [Table 1]

[0133] [Table 2]

[0134] [Table 3]

[0135] [Table 4]

[0136] Based on the above, it has been confirmed that the method for manufacturing printed materials in this embodiment has excellent ink fluidity, storage stability, curability, water-to-weight compatibility, and concentration stability, as well as excellent odor suppression, abrasion resistance, tape adhesion, and lamination compatibility of the printed materials.

Claims

1. An electron beam curable printing ink composition for offset printing, comprising: (A) a polymer of an allyl monomer represented by the following general formula (1); (B) a (meth)acrylate resin; (C) a polyfunctional (meth)acrylate; and (D) a pigment: The aforementioned component (B) is at least one selected from the group consisting of epoxy (meth)acrylate resin, polyester (meth)acrylate resin, and urethane (meth)acrylate resin; The aforementioned component (C) is at least one selected from the group consisting of ditrimethylolpropanetetra(meth)acrylate, tri(meth)acrylate of a trimethylolpropane adduct of 3 moles or more of ethylene oxide, tri(meth)acrylate of a trimethylolpropane adduct of 3 moles or more of propylene oxide, tri(meth)acrylate of a glycerin adduct of 3 moles or more of propylene oxide, and dipentaerythritol hexaacrylate; The aforementioned component (D) contains an extender pigment, The viscosity measured using a cone-plate viscometer at 25°C and a shear rate of 100 / s is between 1.0 Pa·s and 90.0 Pa·s. Electron beam curable printing ink composition. 【Chemistry 1】 (In general formula (1), R １ and R ２ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, X represents an n-valent group having a 4 to 8-membered anticyclic ring skeleton, and n is 2 or 3.

2. The electron beam curable printing ink composition according to claim 1, wherein component (C) is at least one selected from the group consisting of ditrimethylolpropanetetra(meth)acrylate, tri(meth)acrylate of a 3-mol ethylene oxide adduct of trimethylolpropane, tri(meth)acrylate of a 6-mol ethylene oxide adduct of trimethylolpropane, tri(meth)acrylate of a 3-mol propylene oxide adduct of trimethylolpropane, tri(meth)acrylate of a 3-mol propylene oxide adduct of glycerin, and dipentaerythritol hexaacrylate.

3. The electron beam curable printing ink composition according to claim 1 or 2, wherein the content of component (A) in the electron beam curable printing ink composition is 3 to 30% by mass.

4. The electron beam curable printing ink composition according to claim 1 or 2, wherein the content of component (A) in the electron beam curable printing ink composition is 15% by mass or less.

5. The electron beam curable printing ink composition according to claim 1 or 2, wherein the content of component (B) in the electron beam curable printing ink composition is 5 to 60% by mass.

6. The electron beam curable printing ink composition according to claim 1 or 2, wherein the content of component (C) in the electron beam curable printing ink composition is 5 to 60% by mass.

7. The electron beam curable printing ink composition according to claim 1 or 2, wherein the electron beam curable printing ink composition is a surface printing ink composition.

8. The electron beam curable printing ink composition according to claim 1 or 2, wherein the electron beam curable printing ink composition is a reverse printing ink composition.

9. The electron beam curable printing ink composition according to claim 1 or 2, wherein the electron beam curable printing ink composition does not contain a polymerization initiator.

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