Active energy ray curable composition

Abstract

To provide an active energy ray-curable composition that, after application, exhibits excellent curability with active energy ray irradiation, resulting in a coating layer with excellent scratch resistance, rub resistance, and vibration resistance.SOLUTION: An active energy ray-curable composition comprises 10-40 mass% of a urethane acrylate compound, 15-55 mass% of a polyfunctional monomer, 0.2-10 mass% of wax, and 5-20 mass% of a photopolymerization initiator. This composition has a viscosity of 5-45 Pa s at 25°C and is designed for overcoat varnish.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable composition. More specifically, the present invention relates to an active energy ray-curable composition that has excellent curability by irradiation with active energy rays after coating, and has excellent scratch resistance, abrasion resistance, and vibration resistance of the resulting coating film.

Background Art

[0002] Active energy ray-curable overcoat varnishes are widely used in the fields of toy, paperware, food packaging, and cosmetic packaging printing because of their convenience that they are substantially solvent-free, can be cured by irradiation with active energy rays in a very short time without a heat drying process. Active energy ray-curable overcoat varnishes improve abrasion resistance, wear resistance, and blocking resistance to protect the printed surface, and at the same time impart gloss or a matte finish, and are applied to printed materials for upgrading and beautification.

[0003] On the surface of a package containing contents, scratches may occur due to rubbing or impact between packages during product transportation, and depending on the shape and material of the package and the weight and hardness of the contents, scratches that may impair the product value may occur. However, when the crosslinking density is increased to improve abrasion resistance and wear resistance, the flexibility decreases and it becomes brittle. Therefore, in the case of package applications where folds can be made, there is a problem that cracks are likely to occur on the coated surface.

[0004] Therefore, in Patent Document 1, an ultraviolet-curable coating agent composition for forming a cured coating film having excellent fold resistance and the like has been proposed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the coating obtained using the coating agent composition described in Patent Document 1 is prone to scratches due to friction and impact from collisions between product packages under the harsh transportation conditions of recent years, and there is room for improvement in its abrasion resistance.

[0007] This invention has been made in view of the above-mentioned conventional problems, and aims to provide an active energy ray curable composition that exhibits excellent curability by irradiation with active energy rays after application, and in which the resulting coating film has excellent scratch resistance, abrasion resistance, and vibration resistance. [Means for solving the problem]

[0008] The present invention, which solves the above problems, mainly comprises the following configuration.

[0009] (1) An active energy ray curable composition for use as an overcoat varnish, comprising 10-40% by mass of a urethane acrylate compound, 15-55% by mass of a polyfunctional monomer, 0.2-10% by mass of a wax, and 5-20% by mass of a photopolymerization initiator, having a viscosity of 5-45 Pa·s at 25°C.

[0010] With this configuration, the active energy ray curable composition exhibits excellent curability upon irradiation with active energy rays after application, and the resulting coating film has excellent scratch resistance, abrasion resistance, and vibration resistance.

[0011] (2) The active energy ray curable composition according to (1), further comprising 1 to 30% by mass of resin.

[0012] With this configuration, the active energy ray curable composition can be obtained with excellent scratch resistance, abrasion resistance, and vibration resistance.

[0013] (3) The active energy ray curable composition according to (1) or (2), wherein the polyfunctional monomer comprises dipentaerythritol hexaacrylate.

[0014] With this configuration, the active energy ray curable composition can be obtained with excellent curability, scratch resistance, abrasion resistance, and vibration resistance.

[0015] (4) Furthermore, an active energy ray curable composition according to any one of (1) to (3), comprising a matting agent.

[0016] With this configuration, the active energy ray curable composition can impart a matte finish to the resulting coating film. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide an active energy ray curable composition that exhibits excellent curability by irradiation with active energy rays after application, and in which the resulting coating film has excellent scratch resistance, abrasion resistance, and vibration resistance. [Modes for carrying out the invention]

[0018] <Activated energy ray curing type composition> An active energy ray curable composition according to one embodiment of the present invention contains 10 to 40% by mass of a urethane acrylate compound, 15 to 55% by mass of a polyfunctional monomer, 0.2 to 10% by mass of wax, and 5 to 20% by mass of a photopolymerization initiator. The viscosity at 25°C is 5 to 45 Pa·s. The active energy ray curable composition is for use as an overcoat varnish. Each of these will be described below.

[0019] (Urethane acrylate compound) Urethane acrylate compounds are incorporated into active energy ray curable compositions for the purpose of imparting good scratch resistance, abrasion resistance, and vibration resistance to the coating film. The urethane acrylate compound (urethane acrylate resin) is not particularly limited. For example, a urethane acrylate resin is a resin obtained by adding a polyisocyanate component to a polyol component, and then modifying the ends of the urethane resin with acrylic or methacrylic groups. Among these, it is preferable that the urethane acrylate resin includes an aliphatic urethane acrylate resin.

[0020] The mass-average molecular weight of the urethane acrylate resin is preferably 10,000 or less, more preferably 5,000 or less, and even more preferably 2,500 or less. Furthermore, the mass-average molecular weight of the urethane acrylate resin is preferably 500 or more, and more preferably 750 or more. Having the mass-average molecular weight of the urethane acrylate resin within the above range leads to suppression of the molecular weight of the cured product after the reaction, which increases the flexibility of the coating film and thus improves adhesion to the substrate by suppressing internal stress. The number of functional groups (acryloyl groups) of the urethane acrylate is preferably 2 to 6, and more preferably 2 to 3.

[0021] The content of urethane acrylate resin in the active energy ray curable composition may be 10% by mass or more, and preferably 15% by mass or more. Furthermore, the content of urethane acrylate resin may be 40% by mass or less, and preferably 25% by mass or less. If the urethane acrylate resin content is less than 10% by mass, the active energy ray curable composition will not impart sufficient vibration resistance to the coating film. On the other hand, if the urethane acrylate resin content exceeds 40% by mass, the active energy ray curable composition will not impart sufficient scratch resistance and abrasion resistance to the coating film.

[0022] (Polyfunctional monomers) The polyfunctional monomer is incorporated into the active energy ray-curable composition for the purpose of imparting sufficient curability. The polyfunctional monomer is not particularly limited. For example, the polyfunctional monomer may be dimethyloltricyclodecane di(meth)acrylate, (ethoxy(or propoxy)ated) bisphenol A di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (ethoxy(or propoxy)ated) 1,6-hexanediol di(meth)acrylate, (ethoxy(or propoxy)ated) neopentyl glycol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, dipropylene glycol di(meth)acrylate, (neopentyl glycol-modified) trimethylolpropane di(meth)acrylate, tri(meth)acrylate of an ethylene oxide adduct of glycerin, tri(meth)acrylate of a propylene oxide adduct of glycerin, tri(meth)acrylate of an ethylene oxide adduct of trimethylolpropane, tri(meth)acrylate of a propylene oxide adduct of trimethylolpropane, tripropylene glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, pentaerythritol tri(or tetra)(meth)acrylate, trimethylolpropane tri(or tetra)(meth)acrylate, tetramethylolmethane tri(or tetra)(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like.

[0023] The content of the polyfunctional monomer may be 15% by mass or more, preferably 20% by mass or more, in the active energy ray-curable composition. Also, the content of the polyfunctional monomer may be 55% by mass or less, preferably 45% by mass or less, in the active energy ray-curable composition. When the content of the polyfunctional monomer is less than 15% by mass, the active energy ray-curable composition has poor curability. On the other hand, when the content of the polyfunctional monomer exceeds 50% by mass, the active energy ray-curable composition cannot obtain sufficient viscosity and has poor printing suitability.

[0024] (Wax) Wax is incorporated into the active energy ray-curable composition in order to improve scratch resistance. The wax is not particularly limited. For example, the wax may be animal and plant waxes such as beeswax, lanolin wax, spermaceti wax, candelilla wax, carnauba wax, rice wax, wood wax, jojoba oil, mineral waxes such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, petrolatum, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene wax, oxidized polyethylene wax, oxidized polypropylene wax, modified waxes such as montan wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives, hydrogenated waxes such as hydrogenated castor oil, hydrogenated castor oil derivatives, polytetrafluoroethylene wax (PTFE), and the like.

[0025] The average particle diameter of the wax is preferably 10 μm or less, and more preferably 4 μm or less. When the average particle diameter of the wax is within the above range, the active energy ray-curable composition has excellent abrasion resistance and scratch resistance.

[0026] The content of the wax may be 0.2% by mass or more, and preferably 1% by mass or more in the active energy ray-curable composition. Also, the content of the wax may be 10% by mass or less, and preferably 6% by mass or less in the active energy ray-curable composition. When the content of the wax is less than 0.2% by mass, the active energy ray-curable composition is not imparted with sufficient scratch resistance, abrasion resistance and vibration resistance. On the other hand, when the content of the wax exceeds 10% by mass, the active energy ray-curable composition tends to deteriorate workability by soiling the printing apparatus or the like.

[0027] (Photoinitiator) Photopolymerization initiators generate active species such as radicals upon irradiation with active energy rays, thereby initiating the photopolymerization of active energy ray-curable compositions. Photopolymerization initiators are not particularly limited. For example, photoradical polymerization initiators include acylphosphine oxide compounds, triazine compounds, aromatic ketone compounds, aromatic onium salt compounds, organic peroxides, thioxanthone compounds, thiophenyl compounds, anthracene compounds, hexaarylbisimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, halogenated hydrocarbon compounds and alkylamine compounds, iodonium salt compounds and sulfonium salt compounds.

[0028] Acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0029] Triazine compounds include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-pipenyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy-naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, and 2,4-trichloromethyl(4'-methoxystyryl)-6-triazine.

[0030] The photopolymerization initiator may be benzophenone, diethylthioxanthone, 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropan-1-one, 4-benzoyl-4'-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butan-1-one, etc. Examples of such photopolymerization initiators include Irgacure 907, 369, 184, 379, and 819 from BASF, TPO and DETX from Lamberti, and TAZ-204 from Midori Chemical Co., Ltd.

[0031] The photopolymerization initiator content in the active energy ray-curable composition may be 5% by mass or more, and preferably 6% by mass or more. Furthermore, the photopolymerization initiator content may be 20% by mass or less, and preferably 18% by mass or less. If the photopolymerization initiator content is less than 5% by mass, the active energy ray-curable composition will not achieve sufficient curability. On the other hand, if the photopolymerization initiator content exceeds 20% by mass, the active energy ray-curable composition will exhibit reduced scratch resistance, abrasion resistance, and vibration resistance.

[0032] (optional ingredient) The active energy ray curable composition of this embodiment may also contain, in addition to the above components, matting agents, surface modifiers, colorants, polymerization inhibitors, solvents, antiblocking agents, light stabilizers, defoaming agents, ultraviolet absorbers, infrared absorbers, thickeners (thixotropic agents), antibacterial and antifungal agents, etc.

[0033] A matting agent may be added to impart a matte finish to the resulting coating.

[0034] The matting agent is not particularly limited. For example, matting agents include silica, calcium carbonate, and barium sulfate.

[0035] If a matting agent is included, the matting agent content is preferably 3% by mass or more, and more preferably 5% by mass or more, in the active energy ray curable composition. Furthermore, the matting agent content is preferably 20% by mass or less, and more preferably 15% by mass or less. By having a matting agent content within the above range, the active energy ray curable composition can impart a matte finish to the resulting coating film.

[0036] Surface modifiers are preferably added to improve the leveling and slipping properties of the resulting cured product.

[0037] The surface modifier is not particularly limited. Examples include silicone-based surface modifiers, fluorine-based surface modifiers, acrylic-based surface modifiers, acetylene glycol-based surface modifiers, and the like.

[0038] If a surface modifier is included, the content of the surface modifier is preferably 0.01 to 3.00% by mass in the active energy ray curable composition. By having the surface modifier content within the above range, the active energy ray curable composition exhibits excellent leveling and slipping properties.

[0039] Colorants may be added to color the resulting coating film. Alternatively, colorless or colored clear compositions may be prepared by omitting or reducing the amount of colorants.

[0040] From the viewpoint of lightfastness, the coloring agent is preferably a pigment such as an organic pigment or an inorganic pigment. Inorganic pigments include colored pigments such as titanium dioxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, iron black, chromium oxide green, carbon black, and graphite (including achromatic coloring pigments such as white and black), and extender pigments such as calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc. Organic pigments include dye lake pigments, azo pigments, benzimidazolone pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dioxazine pigments, indigo pigments, thioindico pigments, perylene pigments, perinone pigments, diketopyrrolopyrrole pigments, isoindolinone pigments, nitro pigments, nitroso pigments, anthraquinone pigments, flavanthrone pigments, quinophthalone pigments, pyranthrone pigments, and indanthrone pigments.

[0041] If a coloring agent is included, the amount of the coloring agent is preferably 1 to 60% by mass in the active energy ray curable composition.

[0042] The active energy ray curable composition of this embodiment, when containing a pigment, preferably includes a pigment dispersant and a pigment dispersion resin.

[0043] Pigment dispersants include known nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, etc. For example, surfactants include silicone-based surfactants (e.g., polyether-modified silicone oil, polyester-modified polydimethylsiloxane, polyester-modified methylalkylpolysiloxane, etc.), fluorine-based surfactants, oxyalkylene ether-based surfactants, acetylene glycol-based surfactants, phosphoric acid-based surfactants, sulfonic acid-based surfactants, etc.

[0044] Resins for pigment dispersion include polymer dispersants (for example, carbodiimide-based, polyester-based, polyamine-based, polyesteramine-based, polyurethane-based, fatty acid amine-based, polyacrylate-based, polycaprolactone-based, polysiloxane-based, polychain polymer nonionic-based, polymer ionic-based dispersants, etc.).

[0045] If a pigment dispersant or pigment dispersing resin is included, the content of the pigment dispersant or pigment dispersing resin is preferably 1 to 200% by mass relative to the total amount of pigment used.

[0046] Returning to the overall description of the active energy ray curable composition, the method for preparing the active energy ray curable composition of this embodiment is not particularly limited. For example, the active energy ray curable composition can be prepared by adding all the components and stirring and mixing them with a stirring device.

[0047] Furthermore, the active energy ray-curable composition of this embodiment may be prepared by first obtaining a concentrate base by mixing a pigment, a pigment dispersant, and various active energy ray-curable compounds, and then adding active energy ray-curable compounds, polymerization initiators, and optionally surfactants and other additives to the concentrate base to achieve the desired composition.

[0048] Furthermore, the active energy ray curable composition of this embodiment can be mixed, kneaded in a bead mill or a three-roll mill, etc., to disperse the pigment (i.e., coloring components and extender pigments), and then additives (polymerization initiators, polymerization inhibitors, waxes, and other additives) can be added as needed, and the viscosity can be adjusted by adding other components.

[0049] The viscosity (at 25°C) of the active energy ray-curable composition of this embodiment may be 5 Pa·s or higher, and preferably 7 Pa·s or higher. Furthermore, the viscosity (at 25°C) of the active energy ray-curable composition may be 45 Pa·s or lower, and preferably 40 Pa·s or lower. The viscosity can be measured using a Raleigh LA-type viscometer (manufactured by Nippon Rheology Instruments Co., Ltd.). The active energy ray-curable composition may also be used with the addition of an organic solvent during coating to impart coating suitability, leveling properties, etc.

[0050] The active energy ray-curable composition of this embodiment can be used to form a protective layer on the surface of well-known materials, including paper substrates, resin molded surfaces such as various resin sheets, metal surfaces, ceramic surfaces, and wood surfaces. In particular, the active energy ray-curable composition of this embodiment is suitable when scratch resistance and vibration resistance are required. Therefore, the active energy ray-curable composition is especially suitable for use as an overcoat varnish. Furthermore, the means of applying the active energy ray-curable composition are not particularly limited. For example, the active energy ray-curable composition can be applied by known printing and painting methods such as offset printing, gravure printing, flexographic printing, letterpress printing, roller coating, and spray coating.

[0051] Subsequently, the active energy ray-curable composition is cured by irradiation with active energy rays such as ultraviolet light, forming a coating film. The resulting coating film has excellent scratch resistance, abrasion resistance, and vibration resistance. [Examples]

[0052] The present invention will be described in more detail below with reference to examples. The present invention is not limited in any way to these examples. Unless otherwise specified, "%" means "mass percent" and "parts" means "parts by mass". The materials used in the following examples and comparative examples are as follows. The units of the numerical values ​​in the columns for each component and total in the table are "mass percent".

[0053] (Method for preparing resin varnish) (Preparation of resin varnish 1) A work varnish was prepared by mixing 30.4 parts by mass of Daiso Isodap (diallyl isophthalate resin, manufactured by Osaka Soda Co., Ltd.), 68.9 parts by mass of ditrimethylolpropanetetraacrylate, and 0.2 parts by mass of the polymerization inhibitor IRGANOX1010 (pentaerythritol = tetrakis(3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, manufactured by BASF Japan Ltd.) in a ratio of 30.4 parts by mass, and dissolving it at 100°C. To this work varnish, 0.5 parts by mass of ethyl acetacetate aluminum diisopropylate (Kawaken Fine Chemical Co., Ltd., ALCH) was added and stirred at 110°C for 1 hour to prepare resin varnish 1. (Preparation of resin varnish 2-4) Resin varnish 2 was prepared in the same manner as resin varnish 1, except that Daiso Isodap was replaced with Daiso Dap A (diallyl phthalate resin, manufactured by Osaka Soda Co., Ltd.). Resin varnish 3 was prepared in the same way as resin varnish 1, except that Daiso Isodap was replaced with Daiso Dap S (diallyl phthalate resin, manufactured by Osaka Soda Co., Ltd.). Resin varnish 4 was prepared in the same manner as resin varnish 1, except that Daiso Isodap was replaced with Daiso Dap K (diallyl phthalate resin, manufactured by Osaka Soda Co., Ltd.).

[0054] <Resin> Daiso Isodap (diallyl isophthalate resin, manufactured by Osaka Soda Co., Ltd.) Daiso DAP A (diallyl phthalate resin, manufactured by Osaka Soda Co., Ltd.) Daiso Isodap S (diallyl phthalate resin, manufactured by Osaka Soda Co., Ltd.) Daiso Isodap K (diallyl phthalate resin, manufactured by Osaka Soda Co., Ltd.) EBECRYL 8402 (urethane acrylate resin, manufactured by Daicel Ornex Co., Ltd.) CN104 (epoxy acrylate resin, manufactured by Sartomer) CN704 (Polyester acrylate resin, manufactured by Sartomer) <Polyfunctional monomers> Ditrimethylolpropanetetraacrylate DPHA (Dipentaerythritol Hexaacrylate) TMP3EOTA (Triaacrylate of the ethylene oxide (3 molar) adduct of trimethylolpropane) <Photopolymerization initiator> OmniradTPO (diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, manufactured by IGM Resins BV) <Polymerization inhibitors> IRGANOX1010 (Pentaerythritol = Tetrakis(3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate), manufactured by BASF Japan Ltd.) <wax> CERIDUST 9202F (average particle size 2.0-6.0 μm, manufactured by Clariant Japan Co., Ltd.) <Mat agent> SYLYSIA 550 (silica gel, average particle size 3.9 μm, manufactured by Fuji Silysia Chemical Co., Ltd.) <Other> ALCH (Ethyl acetacetate aluminum diisopropylate, manufactured by Kawaken Fine Chemical Co., Ltd.) Surface conditioning agent: BYK-333 (manufactured by Bic Chemie Co., Ltd.) Extender pigment: Shirotsuya CC (calcium carbonate, manufactured by Shiraishi Kogyo Co., Ltd.)

[0055] <Examples 1-12, Comparative Examples 1-11> (Preparation of active energy ray curable compositions) Each material was stirred and mixed according to the formulations shown in Table 1 to prepare the respective active energy ray curable compositions.

[0056] [Table 1]

[0057] The following evaluations were performed on the obtained active energy ray curable compositions.

[0058] (viscosity) The viscosity of the obtained composition at 25°C was measured using a Raleigh LA-type viscometer (manufactured by Nippon Rheology Instruments Co., Ltd.).

[0059] <Preparation of coated objects> The active energy ray curable compositions of the examples and comparative examples were applied using a two-part roll of an RI-2 type color spreader (manufactured by Akira Seisakusho Co., Ltd.) with a coating amount of 0.1 mL / 204 cm². 2 Test specimens were prepared by applying the color to UF coated paper (manufactured by Oji Materia Co., Ltd.) in such a manner, and then irradiating the test specimens with ultraviolet light using a 160 W / cm metal halide lamp (focal length 13 cm, focused type, 1 lamp, manufactured by Heraeus).

[0060] (curable) The degree to which the coating adhered to the fingertip was evaluated when the center of the coated surface of the obtained material was lightly touched with a fingertip. (Evaluation Criteria) ○: The paint film did not adhere at all. △: The coating did not adhere, but tackiness was observed. ×: The paint film adhered and tackiness was observed.

[0061] (Scratch resistance) The obtained coated materials were rubbed with the tip of a fingernail, and the number of times it took for the coating to be scraped off was evaluated according to the following evaluation criteria. (Evaluation Criteria) ○: The paint film could not be removed even after rubbing it 10 times. △: The paint film was scraped off after rubbing it 5 to 10 times. ×: The paint film was scratched off after rubbing it four times or less.

[0062] (Abrasion resistance) The obtained coated samples were placed in a JSPS-type friction tester RT-300 (manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.), and after applying a load of 800g, the coated surfaces were subjected to JSPS friction 10 times. The remaining percentage of the printed coating after the test was visually observed for the removed coated samples and evaluated according to the following evaluation criteria. (Evaluation Criteria) ○: No paint film was removed. △: The paint film was slightly removed, but more than 80% remained. ×: The paint film was removed, and the remaining percentage was less than 80%.

[0063] (Vibration resistance) The obtained coated material was cut to create two test pieces: Test piece A measuring 6.0 cm × 10.8 cm and Test piece B measuring 6.8 cm × 13.5 cm. Test piece A was placed in a vibration testing machine G-8130 (manufactured by Shinken Co., Ltd.) with the coated surface facing upwards. Next, a 2.4 kg weight was attached to the uncoated surface of Test piece B, and it was placed on top of Test piece A so that the coated surfaces were in contact with each other. After a 20-minute vibration test was conducted at an acceleration of 0.3 to 1.0 G, a vibration frequency of 3 to 20 Hz, and a temperature of 10 degrees Celsius, the condition of the coating was visually observed. (Evaluation Criteria) ○: There was no peeling of the paint film, or only minor peeling. △: Peeling of the paint film was observed. ×: Significant peeling of the paint film was observed.

[0064] (Glossy) The 60° reflected gloss value of the colored surface of the obtained coated material was determined using a Murakami-type digital gloss meter (manufactured by Murakami Color Research Institute Co., Ltd.).

[0065] As shown in Table 1, the active energy ray curable compositions of Examples 1 to 12 of the present invention exhibited excellent curability by irradiation with active energy rays after application, and the resulting coating films had excellent scratch resistance, abrasion resistance, and vibration resistance. In particular, the coating films obtained using the active energy ray curable compositions of Examples 10 to 12 showed a matte finish with reduced gloss.

Claims

1. 10 to 40% by mass of urethane acrylate compound, Polyfunctional monomers in an amount of 15 to 55% by mass, The wax is 0.2 to 10% by mass, and It contains 5 to 20% by mass of a photopolymerization initiator. The viscosity at 25°C is 5 to 45 Pa·s. The urethane acrylate compound and the wax contain 1 to 30% by mass of a resin different from the wax, The aforementioned resin includes a diallyl phthalate resin or a diallyl isophthalate resin. An active energy ray curing composition for use as an overcoat varnish.

2. The active energy ray curable composition according to claim 1, wherein the polyfunctional monomer comprises dipentaerythritol hexaacrylate.

3. Furthermore, the active energy ray curable composition according to claim 1 or 2, comprising a matting agent.

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