Active energy ray curable composition, active energy ray curable ink, and method for manufacturing printed materials

Abstract

To provide an active energy ray-curable composition that has superior curability, and can exhibit sufficient adhesion even to a film without an easy-to-bond layer.SOLUTION: An active energy ray-curable composition includes (A) a primary or secondary amine with a conjugate acid pKa of 6.0 or lower, (B) a polyfunctional (meth)acrylate without amino groups, and (C) a compound including a carboxyl group with a weight average molecular weight of 3000 or more and 100000 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable composition, an active energy ray-curable ink, and a method for manufacturing printed materials. [Background technology]

[0002] With the global population increasing, demand for flexible packaging, primarily used for food and household goods, is expected to continue to grow. Gravure printing, currently the mainstream method for printing flexible packaging, produces visually vibrant printed materials. However, gravure printing uses inks containing large amounts of solvent, requiring significant energy for drying and treating the exhaust fumes, resulting in a large environmental impact. Furthermore, in recent years, there has been a demand to reduce the volatile components contained in inks in response to environmental concerns and the need for carbon neutrality.

[0003] For this reason, the use of active energy ray curing methods, which do not contain volatile components and harden instantly by irradiation with active energy rays, is progressing in offset printing, flexographic printing, and related inline anchor coatings and overcoats (Patent Documents 1 and 2). In flexible packaging printing, since printing is done roll-to-roll, the quick drying of the ink is important, and in addition to its environmental advantages, the active energy ray curing method shortens the drying process without using thermal energy, thus saving energy and achieving high productivity.

[0004] However, since the main raw materials for active energy ray curable compositions are generally acrylates, the cured product formed by radical polymerization of these acrylates, i.e., poly(meth)acrylate, has poor adhesion to major films such as polyolefins, polyesters, and polyamides (nylons). As a result, cured films of active energy ray curable compositions have had problems such as peeling during post-processing and insufficient product strength. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-104180 [Patent Document 2] Japanese Patent Publication No. 2019-198970 [Patent Document 3] Japanese Patent Publication No. 2021-98773 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Therefore, studies have been conducted to improve adhesion to the film by providing an easy-adhesion layer on the film side, as described in Patent Document 3. However, this inevitably increases costs and limits the types of films that can be used, resulting in a lack of versatility.

[0007] Therefore, the present invention aims to provide an active energy ray curable composition that exhibits excellent curability and can achieve sufficient adhesion even to films that do not have an easy-adhesion layer. [Means for solving the problem]

[0008] The present invention relates to an active energy ray curable composition comprising a primary or secondary amine (A) having a conjugate acid pKa of 6.0 or less, a polyfunctional (meth)acrylate (B) without an amino group, and a compound (C) having a carboxyl group with a weight-average molecular weight of 3,000 to 100,000.

[0009] Furthermore, the present invention relates to an active energy ray-curable ink, wherein the active energy ray-curable composition of the present invention further contains a pigment.

[0010] The present invention also relates to a method for manufacturing a printed material, comprising, in this order: a transfer step of transferring the active energy ray curable composition or the active energy ray curable ink of the present invention onto a film; an irradiation step of curing the active energy ray curable composition or the active energy ray curable ink by irradiation with active energy rays; and a heating step of heating the film and the cured product of the active energy ray curable composition or the active energy ray curable ink. [Effects of the Invention]

[0011] The active energy ray curable composition according to the present invention exhibits excellent curability and sufficient adhesion even to films that do not have an easy-adhesion layer. [Modes for carrying out the invention]

[0012] The present invention will be described in detail below. In this invention, "greater than or equal to" means the same as or greater than the numerical value shown. Also, "less than or equal to" means the same as or less than the numerical value shown. Furthermore, "(meth)acrylate" is a general term including acrylate and methacrylate, and "(meth)acryloyl group" is a general term including acryloyl group and methacryloyl group.

[0013] The active energy ray curable composition of the present invention contains a primary or secondary amine whose conjugate acid has a pKa of 6.0 or less. Hereinafter, this amine will also be referred to as amine (A). When amine (A) is mixed with a compound having a (meth)acryloyl group and heated, a Michael addition reaction can proceed. In this reaction, because the (meth)acryloyl group is an α-β unsaturated carbonyl compound, the primary or secondary amine undergoes 1,4-conjugation addition to form a 3-aminopropionate structure. Furthermore, if the amino group in the resulting structure is secondary, it may react again to be converted to a tertiary amine. Also, since this reaction is nucleophilic, the higher the nucleophilicity, the milder the conditions under which it proceeds.

[0014] Because the amine (A) has low nucleophilicity, the reaction hardly proceeds when mixed with a compound having a (meth)acryloyl group at room temperature. However, because the reaction does not proceed, the (meth)acryloyl group is not consumed, and the curability of the active energy ray curable composition of the present invention is not reduced. In addition, depending on the type of amine, the thickening due to the progress of the reaction is suppressed, maintaining good coatability of the active energy ray curable composition of the present invention and improving storage stability during storage.

[0015] On the other hand, after curing the active energy ray-curable composition of the present invention with active energy rays, unreacted (meth)acryloyl groups remain in the cured composition. Therefore, when the cured composition is heated, a Michael addition reaction proceeds between the amine (A) and the (meth)acryloyl residue of the radical polymer, yielding a radical polymer having a 3-aminopropionate structure. The amino groups of the polymer strongly interact with polar groups such as hydroxyl groups on the film surface, particularly carboxyl groups, thereby improving the adhesion of the active energy ray-curable composition cured film to the film.

[0016] This adhesion-enhancing effect only occurs when the amino group and the (meth)acrylate radical polymer are covalently bonded within the same compound. For example, if amines and (meth)acrylate polymers are simply mixed, the two compounds are not covalently bonded, so the interaction between the (meth)acrylate crosslinks in the cured film and the film surface does not become stronger, and adhesion does not improve.

[0017] As the amine (A), an aromatic amine is preferred. Specifically, for example, aniline and derivatives substituted at the 1st to 5th positions thereof, N-monosubstituted products of aniline derivatives, isoquinoline, 1,8-naphthyridine, acridine, 1H-triazole, 1H-benzotriazole, 1H-benzimidazole, 1H-imidazole, 1H-pyrazole and other 1H-azoles, and derivatives substituted at positions other than 1H thereof can be mentioned. In particular, 1H-benzotriazole derivatives and 1H-benzimidazole derivatives are highly preferred because of their great effect of improving adhesion.

[0018] As the amine (A), from the viewpoint of suppressing the odor when the active energy ray-curable composition is formed, it is preferably low in volatility, specifically, preferably solid at 25°C and 1 atm.

[0019] As the amine (A), not only monoamines but also polyamines having a plurality of structures with a pKa of the conjugate acid of 6.0 or less can be used.

[0020] A plurality of types of the amine (A) may be used in combination.

[0021] In the active energy ray-curable composition of the present invention, the amine (A) is preferably contained in the active energy ray-curable composition at 5% by mass or more and 30% by mass or less. When the content of the amine (A) is 5% by mass or more, more preferably 10% by mass or more, the film adhesion is further improved. Further, when the content of the amine (A) is 30% by mass or less, more preferably 20% by mass or less, the curability of the active energy ray-curable composition is further improved.

[0022] The active energy ray curable composition of the present invention contains a polyfunctional (meth)acrylate that does not contain an amino group. Hereinafter, this polyfunctional (meth)acrylate will also be referred to as (meth)acrylate (B). The (meth)acrylate (B) hardens upon irradiation with active energy rays to form a film, and from the viewpoint of curability, a highly reactive one is preferred. Furthermore, since it serves as a raw material for the Michael addition reaction by heating with the amine (A), a polyfunctional (meth)acrylate having multiple (meth)acryloyl groups is used. Monofunctional (meth)acrylates generally have low curability and are unsuitable because if they remain as uncured components in the cured film of the active energy ray curable composition, they can become components that can be released from the cured film.

[0023] Furthermore, the (meth)acrylate (B) is preferably low in volatility from a safety and environmental standpoint. Low volatility means that, as defined by the U.S. Environmental Protection Agency (EPA) Method 24, the weight loss rate when heated at 110°C for 1 hour is 1% by weight or less.

[0024] Examples of bifunctional (meth)acrylates (B) include 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, bisphenol A di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate. Examples include 1,3-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, diglycerin di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, and their ethylene oxide adducts, propylene oxide adducts, tetraethylene oxide adducts, etc.

[0025] Examples of trifunctional (meth)acrylates (B) include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, isocyanuric acid tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, and their ethylene oxide adducts, propylene oxide adducts, tetraethylene oxide adducts, etc.

[0026] Examples of tetrafunctional (meth)acrylates (B) include ditrimethylolpropanetetra(meth)acrylate, diglycerintetra(meth)acrylate, ditrimethylolpropanetetra(meth)acrylate, and their ethylene oxide adducts and propylene oxide adducts.

[0027] Examples of (meth)acrylates (B) with five or more functionalities include dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and their ethylene oxide adducts and propylene oxide adducts.

[0028] In particular, when using (meth)acrylates with four or more functions, it is preferable to set the equivalent ratio such that two or more functions react with amines.

[0029] The active energy ray curable composition of the present invention contains a compound having a carboxyl group with a weight-average molecular weight of 3,000 to 100,000. Hereinafter, this compound will also be referred to as compound (C). The amino group of amine (A) and the carboxyl group of compound (C) interact to improve the film formation and film strength of the cured film of the active energy ray curable composition. Furthermore, compound (C) exhibits catalytic activity in the Michael addition reaction between amine (A) and (meth)acrylate (B) due to its carboxyl group. The reaction can only proceed by heating with amine (A) in the presence of compound (C).

[0030] In the active energy ray curable composition of the present invention, the number of moles of carboxyl groups derived from compound (C) is n c (C) and the number of moles n of amino groups derived from the amine (A) a (A) Ratio n c (C) / n a (A) is preferably 0.01 or more and 0.50 or less. c (B) / n a When (A) is 0.01 or higher, it is possible to effectively improve the film formation properties and film strength of the cured film of the active energy ray curable composition. Also, n c (B) / n a When (A) is 0.50 or less, more preferably 0.30 or less, and even more preferably 0.15 or less, an improvement in adhesion due to the interaction between the amino group and the polar group on the film surface can be effectively obtained.

[0031] In the active energy ray curable composition of the present invention, it is preferable that compound (C) has a (meth)acryloyl group or a vinyl group. By having a photosensitive group such as a (meth)acryloyl group or a vinyl group, compound (C) can form a radical copolymer with other (meth)acrylates such as (meth)acrylate (B), improving curability to active energy rays and improving the strength and adhesion of the cured film.

[0032] In the active energy ray curable composition of the present invention, components other than the amine (A), the polyfunctional (meth)acrylate (B), and the compound (C) described below may be included. However, it is preferable that the other components do not have acidic groups. This is because acidic groups may interact with the amine (A) and inhibit the improvement of adhesion.

[0033] The active energy ray-curable composition of the present invention preferably contains a colored pigment. This allows it to be used as an active energy ray-curable ink.

[0034] Examples of the aforementioned colored pigments include phthalocyanine pigments, soluble azo pigments, insoluble azo pigments, lake pigments, quinacridone pigments, isoindoline pigments, surene pigments, metal complex pigments, titanium dioxide, zinc oxide, alumina white, calcium carbonate, barium sulfate, red iron oxide, cadmium red, lead yellow, zinc yellow, Prussian blue, ultramarine blue, oxide-coated glass powder, oxide-coated mica, oxide-coated metal particles, aluminum powder, gold powder, silver powder, copper powder, zinc powder, stainless steel powder, nickel powder, organic bentonite, iron oxide, carbon black, graphite, and the like.

[0035] Furthermore, as the aforementioned pigments, colorless extender pigments such as mica (hydrated aluminum potassium silicate) and talc (magnesium silicate salt) can also be used, and the active energy ray curable composition of the present invention can also be used as a varnish or anchor coating agent.

[0036] The active energy ray-curable composition of the present invention may contain a photopolymerization initiator depending on the active energy ray source. Examples of the photopolymerization initiator include α-aminoalkylphenones, thioxanthones, benzyl ketals, and acylphosphine oxides.

[0037] Furthermore, the active energy ray curable composition of the present invention may use additives such as waxes, pigment dispersants, defoamers, and leveling agents as other components.

[0038] Furthermore, a solvent may be used to adjust the viscosity, but the inclusion of a solvent will reduce the curability of the active energy ray-curable composition of the present invention in relation to active energy rays.

[0039] The active energy ray-curable composition of the present invention can be used as an anchor coating agent, which is transferred to a film and then an active energy ray-curable ink is transferred onto it, or it can be used as an overcoat agent, which is transferred to a film in a patterned manner and then transferred to the film.

[0040] Furthermore, the active energy ray-curable composition of the present invention can also be used as an active energy ray-curable ink containing a colored pigment. That is, the active energy ray-curable ink of the present invention is the active energy ray-curable composition of the present invention further containing a pigment.

[0041] Next, a method for producing the active energy ray curable composition of the present invention will be described.

[0042] The active energy ray curable composition of the present invention can be obtained by mixing the amine (A), the polyfunctional (meth)acrylate (B), the compound (C), and other components such as a photopolymerization initiator as needed, at room temperature to 80°C.

[0043] Degassing under vacuum or reduced pressure conditions is also preferably performed after mixing or during the mixing process.

[0044] Furthermore, when adding colored pigments to make an ink, it is also preferable to add the pigments during the mixing process and then disperse and knead them using an attritor, ball mill, sand mill, three-roll mill, etc., depending on the viscosity.

[0045] The method for manufacturing printed materials of the present invention includes, in this order: a transfer step of transferring the active energy ray curable composition or the active energy ray curable ink of the present invention onto a film; an irradiation step of curing the active energy ray curable composition or the active energy ray curable ink by irradiation with active energy rays; and a heating step of heating the film and the cured product of the active energy ray curable composition or the active energy ray curable ink. Hereinafter, "active energy ray curable composition" may be used as a general term for both the active energy ray curable composition and the active energy ray curable ink.

[0046] Examples of films used in the present invention include polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polylactic acid and other polyesters, polyamides, polyimides, polyalkyl (meth)acrylates, polystyrene, poly-α-methylstyrene, polycarbonate, polyvinyl alcohol, polyvinyl acetal, polyvinyl chloride, and polyvinylidene fluoride.

[0047] Furthermore, films that have a vapor-deposited thin film layer made of a metal or metal compound such as alumina are also used.

[0048] The surface of the film is preferably corona-treated, as this increases the number of polar functional groups on the film surface and improves adhesion to active energy ray-curable compositions or active energy ray-curable inks.

[0049] The surface-treated film can be a commercially available product, or it may be a film that has undergone in-line corona treatment before transferring an active energy ray-curable composition or an active energy ray-curable ink to the film.

[0050] The aforementioned film may have an easy-adhesion coating layer, but this increases the cost. The active energy ray curable composition of the present invention is suitable because it can exhibit sufficient adhesion even to films that do not have an easy-adhesion layer.

[0051] The aforementioned film can be in the form of either a sheet or a roll. When using a thin film for flexible packaging, it is preferable to use a roll film and coat and print it using a roll-to-roll method.

[0052] Methods for transferring the active energy ray-curable composition or active energy ray-curable ink of the present invention to a film include, for example, flexographic printing, offset printing, gravure printing, screen printing, inkjet printing, varnish coater, bar coater, etc. The transfer method is selected depending on the viscosity of the active energy ray-curable composition and whether or not patterning is required.

[0053] Specifically, if patterning is required, printing methods such as flexographic printing, offset printing, gravure printing, screen printing, and inkjet printing are preferred. For full-surface coating, it is preferable to use a varnish coater or bar coater. In terms of viscosity, offset printing and screen printing are preferred for high viscosity of 5 Pa·s to 200 Pa·s, flexographic printing is preferred for 0.1 Pa·s to 5 Pa·s, and gravure printing and inkjet printing are preferred for 0.1 Pa·s or less. Within the aforementioned viscosity range, generally, lower viscosity is preferable because it results in better leveling and a better appearance of the coated product.

[0054] Examples of active energy sources used in the irradiation process include ultraviolet rays, electron beams, and gamma rays. Upon irradiation with active energy rays, the (meth)acryloyl groups react and crosslink by covalent bonds, thereby instantly curing the active energy ray-curable composition.

[0055] For ultraviolet light, UV irradiation devices such as high-pressure mercury lamps, xenon lamps, metal halide lamps, and light-emitting diodes (LEDs) are preferably used. Among these, LED lamps are preferred because they are energy-efficient and produce less ozone. For LEDs, a wavelength of 350 to 420 nm is preferred from the standpoint of energy saving and cost reduction.

[0056] With electron beams, (meth)acryloyl groups are directly radically excited, and radical polymerization proceeds in the active energy ray curable composition, forming a film. Furthermore, electron beams have high permeability and can act on films. When the film is made of polyolefins, radicals are easily generated, causing reactions such as intermolecular crosslinking and decomposition, and radical polymerization proceeds between the active energy ray curable composition and the film, forming covalent bonds between the active energy ray curable composition and the film, resulting in higher adhesion. In particular, electron beams with low acceleration voltages are preferred because they do not require special qualifications for use and are easy to handle. Since the penetration depth of an electron beam is determined by the acceleration voltage, the acceleration voltage is preferably 50kV to 300kV from the viewpoint of sufficient permeability and damage to the film. Also, the irradiation dose of the electron beam is preferably 10kGy to 100kGy, as this increases the amount of radical species generated in the target substance while also increasing damage to the film.

[0057] The heating step promotes a Michael addition reaction between the amine (A) contained in the cured product of the active energy ray-curable composition of the present invention and the (meth)acryloyl residue of the polyfunctional (meth)acrylate (B), thereby improving the adhesion between the cured product of the active energy ray-curable composition and the film. The carboxyl group of compound (C) acts as a catalyst, allowing the reaction to proceed at temperatures of 40°C or higher. By placing this step after the transfer step, it is possible to suppress the decrease in coatability due to thickening caused by the progress of the Michael addition reaction and the decrease in curability due to the consumption of the (meth)acryloyl group. As a result, the curability, coatability, and storage stability of the active energy ray-curable composition of the present invention are improved.

[0058] In the aforementioned heating step, it is preferable that the heating temperature is 40°C to 120°C and the heating time is 2 hours or more.

[0059] The heating temperature is preferably 40°C or higher, and more preferably 60°C or higher, because it increases the rate of the Michael addition reaction. Furthermore, to suppress thermal damage to the film, it is preferably 120°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower.

[0060] The heating time is preferably 2 hours or more, more preferably 4 hours or more, and even more preferably 6 hours or more, in order to complete the reaction. Furthermore, in order to suppress thermal damage to the film, it is preferably 24 hours or less, more preferably 12 hours or less, and even more preferably 8 hours or less.

[0061] Furthermore, the heating process can be performed either before or after post-processing such as lamination, as long as it is done after curing by active energy ray irradiation. [Examples]

[0062] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples.

[0063] [Measurement and Evaluation Methods] (1) Viscosity A B-type viscometer (BROOKFIELD DV-II) was fitted with cylinder spindle No. 4, and the viscosity of each active energy ray curable composition was measured at 25°C and 0.5 rpm. From the viewpoint of coating and printability, a viscosity of 100 Pa·s or less is preferred, and 50 Pa·s or less is more preferred.

[0064] (2) Curability After transferring the active energy ray-curable compositions 1-10 and 12-15 to film 1 using an RI tester, electron beam irradiation was performed using an electron beam irradiation device (EC250 / 30 / 90LS manufactured by Iwasaki Electric Co., Ltd.) at an acceleration voltage of 90kV, with the irradiation dose varied from 10 to 30kGy in 5kGy increments. The minimum irradiation dose at which the cured product did not peel off when cellophane adhesive tape ("Sellotape" (registered trademark) No. 405) was adhered to the cured product and then peeled off was determined. When the minimum irradiation dose was 25-30kGy, the curing performance was good, and when the minimum irradiation dose was 10-20kGy, the curing performance was extremely good.

[0065] (3) Appearance of the coating Regarding the appearance of the coated articles of the active energy ray-curable compositions obtained in the coating processes of each of the examples and comparative examples, the following evaluations were visually conducted. A: The unevenness is small, there is no such problem as voids, and the appearance is good. B: Some voids and the like were scattered. C: The unevenness is large, and voids and the like were generally observed.

[0066] (4) Peel strength To the coated articles of the active energy ray-curable compositions obtained in the coating processes of each of the examples and comparative examples, a mixed laminate adhesive (Takelac A626 / Takenate A50 manufactured by Mitsui Chemicals, Inc.) was applied so that the coating amount was 3.0 g / m 2 and laminated with a non-stretched polypropylene film (CPP) with a thickness of 60 μm (ZK-207 manufactured by Toray Film Processing Co., Ltd.). Thereafter, it was aged at 40°C for 3 days to obtain a laminate sample. The coated portion of the active energy ray-curable composition in the obtained laminate sample was cut into strips with a width of 15 mm, and a peel test was conducted using a tensilon universal testing machine (RTG-1210 manufactured by Orientec Co., Ltd.), and the peel strength when peeled at 300 mm / min at 90° was measured.

[0067] When the peel strength is less than 1.5 N / 15 mm, the adhesion is insufficient. When it is 1.5 N / 15 mm or more and less than 2.0 N / 15 mm, the adhesion is good. When it is 2.0 N / 15 mm or more and less than 3.0 N / 15 mm, the adhesion is quite good. When it is 3.0 N / 15 mm or more, it was judged that the adhesion is extremely good.

[0068] (5) Failure mode In the peel test in (4) above, the state (failure mode) at the time of peeling was also observed. Among the laminate samples having a multilayer structure, the layer where failure occurs at the time of peeling corresponds to the portion where the adhesion is weakest. The failure mode was evaluated by the following A to C. A: The film was broken. B: The active energy ray-curable composition layer underwent cohesive failure. C: Peeling occurred between the film / active energy ray-curable composition layers. Here, "active energy ray curable composition layer" refers to a layer formed by curing an active energy ray curable composition or ink. A is the most preferred option, B is the next preferred option, and C is unpreferred.

[0069] [Amine (A) or its substitute] (A)-1: Indoline (manufactured by Wakken Pharmaceutical Co., Ltd.), secondary amine, pKa of conjugate acid: 4.9. Liquid at 25°C and 1 atm. (A)-2: Aniline (manufactured by Wakken Pharmaceutical Co., Ltd.), primary amine, pKa of conjugate acid: 4.6. Liquid at 25°C and 1 atm. (a)-3: Octadecylamine (manufactured by TCI Corporation), primary amine, pKa of conjugate acid: 10.8. Solid at 25°C and 1 atm. (A)-4:1H-benzotriazole (manufactured by Wakken Pharmaceutical Co., Ltd.), primary amine, pKa of conjugate acid: 1.2. Solid at 25°C and 1 atm.

[0070] [(meth)acrylate (B)] (B)-1: EO-modified trimethylolpropane triacrylate (MIWON "Miramer" (registered trademark) M3190) (B)-2: Ditrimethylolpropanetetraacrylate (MIWON "Miramer" (registered trademark) M410) (B)-3: Tricyclodecanedimethanol diacrylate (Daicel Ornex Co., Ltd. "EBECRYL" (registered trademark) 130).

[0071] [Compound (C) or its substitute] (C)-1: Acrylic resin having a photosensitive group and a carboxylic acid (TWR-1001, manufactured by Toray Industries, Inc.), molecular weight: 30000, acid value: 105 mg KOH / g. (C)-2: Acrylic resin containing carboxylic acid (TWR-3001, manufactured by Toray Industries, Inc.), molecular weight: 27000, acid value: 200 mg KOH / g. (c)-3: Adipic acid (manufactured by Wakken Pharmaceutical Co., Ltd.), molecular weight: 146.

[0072] [Other additives] Pigment: Titanium dioxide ("Typake" (registered trademark) CR58-2, manufactured by Ishihara Sangyo Co., Ltd.) Surfactant 1: ("EMALEX" (registered trademark) 503, manufactured by Nippon Emulsion Co., Ltd.) Surfactant 2: (Disperbyk®, manufactured by Bic Chemie) 111 Photopolymerization initiator: Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (BASF "Irgacure" (registered trademark) 819).

[0073] [Active energy ray curable composition or active energy ray curable ink] Each material was weighed according to the composition shown in Table 1, and dissolved and dispersed using a hybrid mixer (manufactured by Thinky Co., Ltd.). When no pigment was included (active energy ray curable composition 7), it was used as an active energy ray curable composition as is.

[0074] When the active energy ray-curable composition contains a pigment (active energy ray-curable inks 1-6, 9-15), mixing and dispersion were performed using a three-roll mill "EXAKT" (registered trademark) M-80S (manufactured by EXAKT Corporation). In the case of low viscosity (active energy ray-curable ink 8), mixing and dispersion were performed using a batch-type sand mill (manufactured by Hayashi Shoten Co., Ltd.).

[0075] [Table 1] [film] Film 1: 12μm thick PET film (E5102 manufactured by Toyobo Co., Ltd.), with a corona-treated layer. Film 2: 12μm thick PET film (FS2000 manufactured by Futamura Chemical Co., Ltd.), no surface treatment. Film 3: 15 μm thick polyamide film (ON, manufactured by Unitika Ltd.), with a corona-treated layer. Film 4: A barrier film / PET film laminate with a thickness of 12 μm (1011HG SBR2 manufactured by Toray Film Processing Co., Ltd.), without a corona treatment layer. Film 5: 20μm thick OPP film (Toyobo Co., Ltd. P2111), with a corona-treated layer. Film 6: 12μm thick PET film (Toray Industries, Inc.'s "Lumirror" (registered trademark) S10), no surface treatment.

[0076] [Method for manufacturing coated objects 1] Various active energy ray curable compositions or active energy ray curable inks were transferred onto various films. For active energy ray curable compositions without pigments, a bar coater (No. 5) was used for transfer, while for active energy ray curable inks containing pigments, an RI tester was used. The films were then cured by electron beam irradiation using an electron beam irradiation device (EC250 / 30 / 90LS, manufactured by Iwasaki Electric Co., Ltd.) with an acceleration voltage of 110 kV and an irradiation dose of 40 kGy. After that, they were heated at 80°C for 12 hours.

[0077] [Method for manufacturing coated objects 2] Various types of active energy ray-curable inks were transferred onto various films. An RI tester was used for the transfer method. Then, an irradiation device (UD90, manufactured by Panasonic Devices SUNX Co., Ltd.) was used to irradiate the films at an intensity of 8 W / cm². 2 The material was cured by LED-UV irradiation with a wavelength of 385 nm. It was then heated at 80°C for 12 hours.

[0078] [Method for manufacturing coated objects 3] For various films, a corona treatment device (TEC-4AX, manufactured by Kasuga Electric Co., Ltd.) was used, with a discharge rate E of 200 W·min / m². 2 After corona treatment under these conditions, various active energy ray-curable inks were transferred. An RI tester was used for the transfer method. Then, curing was performed by electron beam irradiation using an electron beam irradiation device (EC250 / 30 / 90LS manufactured by Iwasaki Electric Co., Ltd.) with an acceleration voltage of 110kV and an irradiation dose of 40kGy. After that, it was heated at 80°C for 12 hours.

[0079] [Example 1] A coated object was prepared using active energy ray-curable ink 1 as the active energy ray-curable ink and film 1 as the film, according to coating preparation method 1. The peel strength was extremely good at 3.7 N / 15 mm, there was no peeling at a dose of 20 kGy, the curability was good, the fracture mode was good (A), and the appearance of the coated object was also good. The results are shown in Table 2.

[0080] [Examples 2-10 and Comparative Examples 1-4] As active energy ray curable compositions, active energy ray curable compositions 7 and active energy ray curable inks 2-6, 8-10, 12-15 were used as the corresponding active energy ray curable compositions as shown in Table 2, and film 1 was used as the film to prepare coated articles according to method 1. In Examples 2-10, the peel strength was good or better in all cases, but Examples 2, 5, 7, 8, 9, and 10, in which the amine content was within a preferred range, showed extremely good appearance and adhesion. Comparative Examples 1-3 showed insufficient peel strength and failure mode. Comparative Example 4 showed good adhesion, but the Michael addition reaction proceeded at room temperature, resulting in high viscosity and poor curability due to the consumption of acryloyl groups. The results are shown in Table 2.

[0081] [Examples 11-15] Coated objects were prepared using Active Energy Ray Curable Ink 1 as the active energy ray curable ink and Films 2-6 as shown in Table 3, according to Method 1 for Preparation of Coated Objects. The peel strength was good or better for all films, and particularly excellent for the corona-treated films. The results are shown in Table 3.

[0082] [Examples 16 and 17] A coated object was prepared by UV curing using active energy ray-curable ink 11 as the active energy ray-curable ink and films 1 and 2 as shown in the correspondence in Table 3, according to coating method 2. The peel strength was good or better for both films, and was particularly good for corona-treated film 1.

[0083] [Examples 18 and 19] Coated objects were prepared using active energy ray-curable ink 1 as the active energy ray-curable ink and films 2 and 4 as shown in Table 3, according to method 3 for preparing coated objects. Corona treatment resulted in extremely good peel strength for both films. The results are shown in Table 3.

[0084] [Table 2]

[0085] [Table 3]

Claims

1. An active energy ray curable composition comprising a primary or secondary amine (A) having a conjugate acid pKa of 6.0 or less, a polyfunctional (meth)acrylate (B) without an amino group, and a compound (C) having a carboxyl group with a weight-average molecular weight of 3,000 to 100,000.

2. The active energy ray curable composition according to claim 1, wherein the amine (A) is an aromatic amine.

3. The active energy ray curable composition according to claim 1 or 2, wherein the amine is one or more selected from 1H-benzotriazole derivatives and 1H-benzimidazole derivatives.

4. The active energy ray curable composition according to claim 1 or 2, wherein the amine (A) is solid at 25°C and 1 atm.

5. The number of moles of carboxyl groups derived from the compound (C) is n ｃ (C) and the number of moles of amino groups derived from the amine (A) n ａ (A) Ratio n ｃ (C) / n ａ The active energy ray curable composition according to claim 1 or 2, wherein (A) is 0.01 or more and 0.50 or less.

6. The active energy ray curable composition according to claim 1 or 2, wherein the compound (C) has a meth(acryloyl) group or a vinyl group.

7. The active energy ray curable composition according to claim 1 or 2, wherein the components other than the amine (A), the (meth)acrylate (B), and the compound (C) do not have an acidic group.

8. An active energy ray-curable ink comprising the active energy ray-curable composition described in claim 1, further comprising a pigment.

9. A method for manufacturing a printed article, comprising, in this order: a transfer step of transferring an active energy ray-curable composition according to claim 1 or an active energy ray-curable ink according to claim 8 onto a film; an irradiation step of curing the active energy ray-curable composition or the active energy ray-curable ink by irradiation with active energy rays; and a heating step of heating the film and the cured product of the active energy ray-curable composition or the active energy ray-curable ink.

10. The method for manufacturing a printed article according to claim 9, wherein the surface of the film is corona treated.

11. The method for manufacturing a printed article according to claim 9, wherein in the heating step, the heating temperature is 40°C to 120°C and the heating time is 2 hours or more.

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