Active energy ray-curable composition

Abstract

To provide an active energy ray-curable composition in which dripping or tackiness of a dry film is suppressed before curing, and, even when coated on a vertical surface or a complicated shape, an obtained cured material has excellent aesthetic property, improved mechanical properties such as hardness and film strength, and is also excellent in weather resistance.SOLUTION: (A)A composition comprising a compound having an ethylenically unsaturated group, in which the storage elastic modulus G'(measurement frequency 1 Hz) at 80°C of a dry film before active energy ray is irradiated is 10 Pa or larger. The (A) component is preferred that the component (A) contains a (meth) acrylate polymer having an ethylenically unsaturated group in a (A1) side chain. This composition can be suitably used for coating materials such as coatings.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable composition that can suppress dripping and tackiness of a dried coating film before curing, and therefore can produce a cured product that has excellent appearance even when applied to a vertical surface or an object with a complex shape, and that is also excellent in hardness, mechanical properties, and weather resistance, and can be suitably used in applications such as coating agents for paints and adhesives. [Background technology]

[0002] BACKGROUND ART Compositions that are cured by active energy rays such as ultraviolet rays or electron beams have advantages over thermosetting compositions, such as low-temperature curing, less energy required for curing, a short curing time, and high productivity, and are therefore used in a wide range of fields, such as coating agents and adhesives.

[0003] For example, Patent Documents 1, 2, and 3 disclose active energy ray-curable coating agent compositions containing, as curable components, a compound having two or more (meth)acryloyl groups and various other compounds having an ethylenically unsaturated group.

[0004] However, when the coating compositions of Patent Documents 1, 2 and 3 are applied to a vertical surface, they tend to drip before curing, which impairs the aesthetic appearance of the cured product. Furthermore, when these compositions are applied to objects having complex shapes, the amount of active energy rays irradiated varies significantly depending on the location, and physical properties such as hardness and film strength are significantly poor in areas exposed to low amounts of radiation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-120781 [Patent Document 2] International Publication No. WO15 / 133560 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-51654 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention addresses the problem of providing an active energy ray-curable composition that suppresses dripping and tackiness of a dried coating before curing, and that provides a cured product that has excellent aesthetic appearance even when applied to a vertical surface or an object with a complex shape, and that also has improved mechanical properties such as hardness and film strength, and excellent weather resistance. [Means for solving the problem]

[0007] As a result of extensive research to solve the above-mentioned problems, the present inventors have found that by setting the storage modulus, as determined by viscoelasticity measurement, of a dried coating of a composition before irradiation with active energy rays to a certain value or higher, dripping and tackiness of the dried coating before irradiation can be suppressed, and therefore a cured product having excellent hardness, mechanical properties, and weather resistance can be obtained even in areas with low irradiation doses or areas that have not been irradiated, and have thus completed the present invention.

[0008] The present invention relates to an active energy ray-curable composition comprising (A) a compound having an ethylenically unsaturated group (hereinafter also referred to as "component (A)"), wherein the composition produces a dry coating film having a storage modulus G' at 80°C (measured at a frequency of 1 Hz) of 10 Pa or more before exposure to active energy rays. The component (A) preferably contains (A1) a (meth)acrylate polymer having an ethylenically unsaturated group in the side chain (hereinafter also referred to as "component (A1)"). The component (A1) preferably comprises a reaction product of a copolymer (a1) (hereinafter referred to as "copolymer (a1)") containing a structural unit derived from a (meth)acrylate monomer (a1-1) having no reactive group and a structural unit derived from a (meth)acrylate monomer (a1-2) having a reactive group selected from the group consisting of an epoxy group, a carboxyl group, a hydroxyl group, and an isocyanate group, and a compound (a2) (hereinafter referred to as "unsaturated compound (a2)") having a group reactive with the reactive group and an ethylenically unsaturated group. The unsaturated compound (a2) is preferably an unsaturated double bond-containing oligomer (a2-1) having a glass transition temperature (Tg) of -30 to -90°C.

[0009] In another embodiment of the present invention, a composition further containing (B) a solvent is preferred. In another embodiment of the present invention, a composition that further contains, as the component (A), a compound having an ethylenically unsaturated group other than the component (A1) (hereinafter also referred to as "component (A2)"). The active energy rays are preferably electron beams. In another embodiment of the present invention, a composition further containing (C) a photopolymerization initiator is preferred.

[0010] The composition of the present invention is preferably used as an active energy ray-curable composition for coating agents. [Effects of the Invention]

[0011] According to the present invention, in the active energy ray-curable composition containing (A) a compound having an ethylenically unsaturated group, the 80°C storage modulus G' (measured at a frequency of 1 Hz) of the dried coating before irradiation with active energy rays is set to 10 Pa or more. This not only makes it possible to suppress dripping and tackiness of the dried coating of the composition before irradiation, but also makes it possible to improve the hardness of the cured product even in areas with low irradiation doses or areas that were not irradiated, even when the composition is applied to a vertical surface or an object with a complex shape. As a result, it is possible to obtain a cured product that is excellent in appearance and has improved mechanical properties such as hardness and film strength, as well as weather resistance. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below. The present invention relates to an active energy ray-curable composition comprising (A) a compound having an ethylenically unsaturated group, wherein the active energy ray-curable composition produces a dry coating film having a storage modulus G' at 80°C (measured at a frequency of 1 Hz) of 10 Pa or more before irradiation with active energy rays. The component (A), the active energy ray-curable composition, and the method of use will be described below. In the present invention, the term "(meth)acrylate polymer" refers to a polymer containing (meth)acrylate as a main component of the structural unit, the term "(meth)acrylate" refers to acrylate and / or methacrylate, the term "(meth)acrylic" refers to acrylic and / or methacrylic, and the term "(meth)acryloyl" refers to acryloyl and / or methacryloyl.

[0013] 1. (A) component Component (A) is a compound having an ethylenically unsaturated group, and is not particularly limited as long as it forms the curable component of the active energy ray-curable composition, and the composition, either alone or mixed with other components, exhibits a storage modulus G' (measurement frequency 1 Hz) at 80°C of at least 10 Pa when dried before irradiation with active energy rays. The composition preferably comprises 30 to 100% by mass of component (A) and 0 to 70% by mass of other components.

[0014] As the component (A), a (meth)acrylate polymer having an ethylenically unsaturated group in the side chain, which is the component (A1), is preferred. As described above, the (meth)acrylate polymer refers to a polymer containing (meth)acrylate as the main component of the structural units, and refers to a polymer containing 80 to 100% by weight of (meth)acrylate in all structural monomer units. The component (A) of the present invention may be a compound having an ethylenically unsaturated group other than the component (A1), which is the component (A2). The components (A1) and (A2) will be described below.

[0015] 1-1. (A1) component The component (A1) is a (meth)acrylate polymer having an ethylenically unsaturated group in the side chain. The component (A1) is preferably a reaction product of a copolymer (a1) containing a structural unit derived from a (meth)acrylate monomer (a1-1) (hereinafter also referred to as "monomer (a1-1)") that does not have a reactive group and a structural unit derived from a (meth)acrylate monomer (a1-2) (hereinafter also referred to as "monomer (a1-2)") that has a reactive group, and a compound (a2) (hereinafter also referred to as "unsaturated compound (a2)") that has a group that reacts with the reactive group and an ethylenically unsaturated group. That is, the component (A1) is preferably a polymer having an ethylenically unsaturated group bonded as a side chain, obtained by reacting a reactive group of the backbone polymer (a1) with a reactive group of the unsaturated compound (a2). The "reactive group" in the monomer (a1-1) and the monomer (a1-2) means a functional group other than a (meth)acryloyl group. The copolymer (a1), the unsaturated compound (a2), the method for producing the component (A1), and the physical properties of the component (A1) will be described below.

[0016] (1) Copolymer (a1) Copolymer (a1), which is the raw material copolymer for component (A1), is a copolymer comprising structural units derived from monomer (a1-1) and structural units derived from monomer (a1-2). The monomer (a1-1) and the monomer (a1-2) will be described below.

[0017] (1-1) Monomer (a1-1) The monomer (a1-1) is a (meth)acrylate monomer (a1-1) having no reactive group. Specific examples of the monomer (a1-1) are not particularly limited as long as they are (meth)acrylate-based monomers that do not have the above-mentioned reactive group, and include, for example, alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tetradecyl (meth)acrylate, and stearyl (meth)acrylate; alicyclic (meth)acrylates such as isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyl (meth)acrylate; N-(meth)acryloylmorpholine; Acrylamides such as (meth)acrylamide, N-methylolacrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and N,N-dimethylaminopropyl(meth)acrylamide; and Examples include acrylonitrile and methacrylonitrile.

[0018] (1-2) Monomer (a1-2) The monomer (a1-2) is a (meth)acrylate monomer having a reactive group. The monomer (a1-2) is preferably a (meth)acrylate monomer having a reactive group selected from the group consisting of an epoxy group, a carboxyl group, a hydroxyl group, and an isocyanate group.

[0019] Examples of the monomer (a1-2) having an epoxy group as a reactive group include glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate glycidyl ether.

[0020] Examples of the monomer (a1-2) having a hydroxyl group as a reactive group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and an ε-caprolactone adduct of 2-hydroxyethyl (meth)acrylate.

[0021] An example of the monomer (a1-2) having an isocyanate group as a reactive group is (meth)acryloxyethyl isocyanate, and specific products include "Karenz MOI" and "Karenz AOI" (both trade names, manufactured by Showa Denko).

[0022] Examples of the monomer (a1-2) having a carboxyl group as a reactive group include (meth)acrylic acid, phthalic acid monohydroxyethyl acrylate, ω-carboxy-polycaprolactone (n≈2) monoacrylate, (meth)acryloyloxyethyl succinate, (meth)acryloyloxyethyl hexahydrophthalate, (meth)acryloyloxyethyl phthalate, (meth)acryloyloxyethyl-2-hydroxyethyl phthalate, β-carboxyethyl acrylate, a phthalic anhydride adduct of pentaerythritol triacrylate, a succinic anhydride adduct of pentaerythritol triacrylate, a succinic anhydride adduct of dipentaerythritol triacrylate, and a phthalic anhydride adduct of dipentaerythritol triacrylate.

[0023] (1-3) Polymerization method of copolymer (a1) The method for producing the copolymer (a1) before reacting with the unsaturated compound (a2) is not particularly limited, and known methods such as suspension polymerization, emulsion polymerization, solution polymerization, and bulk polymerization can be used. Among these, bulk polymerization and solution polymerization are preferred because they allow easy production of polymers and do not contain impurities such as emulsifiers.

[0024] (1-3-1) Solution polymerization The solution polymerization method includes a method in which the raw material monomers to be used are dissolved in an organic solvent, a thermal polymerization initiator is added, and the mixture is heated and stirred. When synthesis is performed by radical polymerization using the solution polymerization method, the raw material monomers to be used are dissolved in an organic solvent, a thermal radical polymerization initiator is added, and the mixture is heated and stirred to obtain the polymer. If necessary, a chain transfer agent can be used to adjust the molecular weight of the polymer.

[0025] Examples of organic solvents used in solution polymerization include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate; ethers such as propylene glycol monomethyl ether; aromatic hydrocarbons such as toluene and xylene; and aliphatic hydrocarbons such as hexane, heptane, and mineral spirits.

[0026] Examples of the thermal polymerization initiator include azo-based initiators such as azobisisobutyronitrile, azobisisovaleronitrile, azobiscyclohexanecarbonitrile, and azobiscyanovaleric acid; organic peroxides such as t-butyl peroxypivalate, t-hexyl peroxypivalate, dilauroyl peroxide, di(2-ethylhexyl)peroxydicarbonate, di-t-butyl peroxide, and dicumyl peroxide; and hydrogen peroxide-iron(II) salt, peroxodisulfate-sodium hydrogensulfite, and cumene hydroperoxide-iron(II) salt. The proportion of the thermal polymerization initiator used may be appropriately set depending on the target molecular weight. The proportion of the thermal radical polymerization initiator used is preferably 0.1 to 10 parts by weight per 100 parts by weight of the total of all the monomers used.

[0027] (1-3-2) Bulk polymerization Examples of the bulk polymerization method include known methods disclosed in JP-A Nos. 57-502171, 59-6207, and 60-215007. For example, a method can be mentioned in which a pressurizable reactor is filled with a solvent, and the reactor is set at a predetermined temperature under pressure, and then a monomer mixture comprising each monomer and, if necessary, a polymerization solvent is fed to the reactor at a constant feed rate, and a polymerization liquid is withdrawn in an amount corresponding to the amount of the monomer mixture fed. If necessary, a polymerization initiator can be blended into the monomer mixture, and the blending amount, if any, is preferably 0.001 to 2 parts by weight per 100 parts by weight of the monomer mixture. The pressure depends on the reaction temperature and the boiling points of the monomer mixture and solvent used, and may be any pressure that does not affect the reaction but can maintain the desired reaction temperature. The residence time of the monomer mixture is preferably 1 to 60 minutes. If the residence time is less than 1 minute, the monomers may not react sufficiently, and if the residence time exceeds 60 minutes, productivity may decrease. The preferred residence time is 2 to 40 minutes.

[0028] Examples of polymerization initiators used to obtain copolymer (a1) include any initiator that generates radicals at a predetermined reaction temperature. Specific examples include organic peroxides such as di-t-butyl peroxide, di-t-hexyl peroxide, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, cumene hydroperoxide, and t-butyl hydroperoxide, and azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), azobiscyclohexacarbonitrile, azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-amidinopropane) dihydrochloride, and 4,4'-azobis(4-cyanovaleric acid). These polymerization initiators may be used alone or in combination.

[0029] The amount of the polymerization initiator used can be adjusted appropriately depending on the types of polymerization initiator and monomer, the desired molecular weight, polymerization conditions, etc., but is generally 0.001 to 10 parts by weight per 100 parts by weight of the monomer used.

[0030] When an organic solvent is used to produce the copolymer (a1), an organic hydrocarbon compound is suitable, and examples thereof include cyclic ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbon compounds such as benzene, toluene and xylene, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, and alcohols such as methanol, ethanol and isopropanol, and one or more of these can be used. Organic solvents that do not dissolve the (meth)acrylate copolymer well tend to cause scale growth on the walls of the reactor, which can lead to production problems during cleaning processes and the like.

[0031] The amount of organic solvent used is preferably 80 parts by weight or less relative to 100 parts by weight of the total vinyl monomers. By using 80 parts by weight or less, a high conversion rate can be obtained in a short time. More preferably, it is 1 to 50 parts by weight. In addition, a dehydrating agent such as trimethyl orthoacetate or trimethyl orthoformate can also be added. A known chain transfer agent may be used in the production of the copolymer (a1).

[0032] The reaction liquid withdrawn from the reactor can be directly used in the next step, or the polymer can be isolated by removing volatile components such as unreacted monomers, organic solvents, and low-molecular-weight oligomers by distillation, etc. A portion of the volatile components such as unreacted monomers, organic solvents, and low-molecular-weight oligomers distilled off from the reaction liquid can be returned to the raw material tank or directly to the reactor and reused in the polymerization reaction. Recycling the unreacted monomers and the organic solvent is an economically preferable method. When recycling, it is necessary to determine the mixing ratio of the newly fed monomer mixture so as to maintain the desired monomer ratio and the desired amount of organic solvent in the reactor.

[0033] (1-3-3) Physical properties of copolymer (a1) The weight-average molecular weight (hereinafter also referred to as "Mw") of copolymer (a1) is preferably 1,500 to 50,000, more preferably 1,500 to 40,000, even more preferably 2,000 to 30,000, even more preferably 2,500 to 25,000, and particularly preferably 3,000 to 15,000. By ensuring that Mw is 50,000 or less, the resulting component (A1) can be made low-viscosity even at relatively high concentrations, improving coatability and compatibility when mixed with other curable resins. By ensuring that Mw is 1,500 or more, the resulting cured product of component (A1) will have excellent weather resistance and tensile properties. In the present invention, Mw means a value obtained by converting the molecular weight measured by gel permeation chromatography (hereinafter referred to as GPC) into polystyrene equivalent.

[0034] The Tg (glass transition temperature) of the copolymer (a1) is not particularly limited, but is preferably 0°C or higher and 90°C or lower. A Tg of 0°C or higher results in excellent strength of the cured product, while a Tg of 90°C or lower results in excellent flexibility of the cured product. The Tg of the copolymer (a1) is more preferably 20 to 80°C, and even more preferably 30 to 75°C. The Tg of the copolymer (a1) can be adjusted by appropriately selecting the types and copolymerization ratio of the monomers constituting the copolymer (a1).

[0035] In the present invention, Tg is determined from the intersection of the baseline and the tangent at the inflection point of a heat flux curve obtained using a differential scanning calorimeter such as a TA Instruments (Q-100) etc. The heat flux curve is obtained by cooling approximately 10 mg of a sample to -100°C in a nitrogen atmosphere, holding it for 5 minutes, then heating it to 300°C at a rate of 10°C / min, further cooling it to -100°C, holding it for 5 minutes, and then heating it to 350°C at a rate of 10°C / min.

[0036] In the case of a typical solution polymerization method such as that disclosed in JP 2014-115538 A, the polymerization temperature is relatively low, and therefore the number of functional groups varies among polymer molecules due to the influence of the copolymerization reactivity ratio. On the other hand, in the case of high-temperature polymerization, the influence of the copolymerization reactivity ratio is reduced, and in the case of continuous polymerization, a constant polymer continues to be produced, so the variation in the number of functional groups among molecules becomes extremely small. Furthermore, when comparing conventional solution polymerization with high-temperature polymerization, when synthesizing a polymer of the same molecular weight, high-temperature polymerization requires less polymerization initiator and leaves less initiator residue, resulting in better weather resistance. In particular, in the case of electron beam curing, since no polymerization catalyst such as a photoinitiator is used in the curing reaction, the amount of initiator residue contained in the polymer has a significant effect on weather resistance. Therefore, the copolymer (a1) used in the present invention generally preferably has a terminal double bond concentration of 0.5 meq / g or less, more preferably 0.4 meq / g or less. When the terminal double bond concentration is 0.5 meq / g or less, a decrease in the curing rate can be suppressed. Furthermore, when a copolymer obtained by high-temperature continuous polymerization is used as the copolymer (a1) in the present invention, the terminal double bond concentration of the copolymer (a1) is preferably 0.02 meq / g or more and 0.5 meq / g or less. By having a terminal double bond concentration of 0.02 meq / g or more, rapid curing during curing is suppressed, and residual stress is less likely to remain, resulting in improved mechanical properties.

[0037] (2) Unsaturated compound (a2) The unsaturated compound is not particularly limited as long as it is a compound (a2) having an unsaturated double bond and a group reactive with the reactive group derived from the (meth)acrylate monomer (a1-2) constituting the copolymer (a1). However, an unsaturated double bond-containing oligomer (a2-1) having a Tg of −30 to −90° C. is preferred. Here, the unsaturated double bond is preferably an ethylenically unsaturated group, and specific examples include a (meth)acryloyl group and a vinyl group, of which a (meth)acryloyl group is more preferred, and an acryloyl group is particularly preferred. In the present invention, the oligomer means a compound having a molecular weight of 250 or more and 2,000 or less. As described above, the component (A1) can be obtained by reacting the reactive group in the copolymer (a1) obtained by the above polymerization method with the reactive group of the unsaturated compound (a2). More specifically, the component (A1) can be obtained by chemically bonding and adding the unsaturated compound (a2) to the copolymer (a1) having the reactive group via the reactive group.

[0038] When the copolymer (a1) is an epoxy polymer or a copolymer having a hydroxyl group as a reactive group, the unsaturated compound (a2) can be a compound having a carboxyl group or an isocyanate group as a functional group that reacts with the reactive group.

[0039] Examples of the unsaturated compound (a2) having a carboxyl group include acrylic acid, acrylic acid dimer, a γ-butyrolactone adduct of acrylic acid, and a δ-valerolactone adduct of acrylic acid. Other specific examples include unsaturated oligomers (a2-1) such as ε-caprolactone adducts of (meth)acrylic acid. ε-caprolactone adducts of acrylic acid are commercially available, and examples thereof include Aronix M-5300 (trade name, manufactured by Toagosei Co., Ltd., Tg=−78° C., polycaprolactone chain length≈2).

[0040] Examples of the unsaturated compound (a2) having an isocyanate group include unsaturated oligomers (a2-1) such as 2-((meth)acryloyloxy)ethyl isocyanate and urethane (meth)acrylate having an isocyanate group at one end. Urethane acrylates with an isocyanate group at one end can be prepared by reacting a diol with a diisocyanate to produce a compound with isocyanate groups at both ends, and then reacting this compound with a hydroxyl group-containing acrylate. Examples of diisocyanates include isophorone diisocyanate and hexamethylene diisocyanate, and examples of diols include polytetramethylene glycol. Examples of hydroxyl group-containing acrylates include 2-hydroxyethyl acrylate. Examples of methods for producing the compound include a method in which a diisocyanate and a diol are reacted in an organic solvent in the presence of a tin catalyst such as dioctyltin to obtain a urethane oligomer having isocyanate groups at both ends, and then a hydroxyl group-containing (meth)acrylate is reacted in the presence of a polymerization inhibitor.

[0041] When the copolymer (a1) is a copolymer having an isocyanate group or a carboxyl group as a reactive group, the unsaturated compound (a2) may be a compound having a hydroxyl group as a functional group that reacts with the reactive group. Examples of the unsaturated compound (a2) having a hydroxyl group include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, and 4-hydroxybutyl acrylate. Other specific examples include unsaturated oligomers (a2-1) such as ε-caprolactone adducts of hydroxyalkyl (meth)acrylates, such as ε-caprolactone adducts of 2-hydroxyethyl (meth)acrylate, polypropylene glycol adducts of (meth)acrylic acid, polyethylene glycol adducts of (meth)acrylic acid, poly(3-hydroxybutyrate) adducts of 2-hydroxyethyl (meth)acrylate, and polytetramethylene glycol adducts of (meth)acrylic acid. Adducts of 2-hydroxyethyl (meth)acrylate with ε-caprolactone are commercially available, and examples thereof include Placcel FA2D (an adduct of 2-hydroxyethyl acrylate with ε-caprolactone, manufactured by Daicel Corporation, trade name; the same applies hereinafter; molecular weight: 344, Tg = -78°C), FA5 (an adduct of 2-hydroxyethyl acrylate with ε-caprolactone, molecular weight: 689), FM2D (an adduct of 2-hydroxyethyl methacrylate with ε-caprolactone, molecular weight: 358), FM3 (an adduct of 2-hydroxyethyl methacrylate with ε-caprolactone, molecular weight: 473), and FM5 (an adduct of 2-hydroxyethyl methacrylate with ε-caprolactone, molecular weight: 701). An example of a polypropylene glycol adduct of acrylic acid is a compound having a Tg of -75°C, an example of a polyethylene glycol adduct of acrylic acid is a compound having a Tg of -41°C, an example of a poly(3-hydroxybutyrate) adduct of 2-hydroxyethyl acrylate is a compound having a Tg of -40°C, and an example of a polytetramethylene glycol adduct of acrylic acid is a compound having a Tg of -84°C.

[0042] The unsaturated oligomer (a2-1) is preferably an unsaturated oligomer containing a ring-opened caprolactone structure (hereinafter also referred to as "caprolactone-based unsaturated oligomer"), more preferably a caprolactone-based unsaturated oligomer having a Tg of -30 to -90° C. Compositions containing the component (A1) obtained using such compounds are preferred in that the cured products thereof have excellent elongation percentages. Specific examples of the compound include the compounds listed above. Examples of the caprolactone-based unsaturated oligomer (a2-1) having a carboxyl group include the above-mentioned ε-caprolactone adduct of (meth)acrylic acid. Examples of the caprolactone-based unsaturated oligomer (a2-1) having a hydroxyl group include the above-mentioned ε-caprolactone adducts of hydroxyalkyl (meth)acrylates, such as the ε-caprolactone adducts of 2-hydroxyethyl (meth)acrylate.

[0043] (3) Production method of (A1) component The component (A1) is preferably produced by reacting a reactive group of the copolymer (a1) with a group in the unsaturated compound (a2) that is reactive with the reactive group described above. This reaction is hereinafter also referred to as a "modification reaction." That is, examples of the reaction for adding an unsaturated compound (a2) to a copolymer (a1) include a method of reacting a copolymer (a1) having an epoxy group or a hydroxyl group as a reactive group with an unsaturated compound (a2) having a carboxyl group, and a method of reacting a copolymer (a1) having an isocyanate group or a carboxyl group as a reactive group with an unsaturated compound (a2) having a hydroxyl group. Among these, the method of reacting a copolymer (a1) having an epoxy group as a reactive group with an unsaturated compound (a2) having a carboxyl group is preferred.

[0044] The reaction ratio of the copolymer (a1) and the unsaturated compound (a2) may be appropriately set depending on the type of component (A1) to be produced. The amount of the reactive group in the unsaturated compound (a2) is preferably 0.5 to 1.5 mol, more preferably 0.8 to 1.2 mol, and even more preferably 0.9 to 1.1 mol, per 1 mol of the reactive group in the copolymer (a1).

[0045] As a method for reacting and adding the unsaturated compound (a2) having a carboxyl group to the copolymer (a1) having an epoxy group, there can be mentioned a method in which the copolymer (a1) having an epoxy group, the unsaturated compound (a2) having a carboxyl group, a catalyst, and an organic solvent are mixed and heated to 60 to 120°C for about 5 to 30 hours.

[0046] The reaction ratio of the copolymer (a1) having an epoxy group and the unsaturated compound (a2) having a carboxyl group is preferably 0.5 to 1.5 moles, more preferably 0.8 to 1.2 moles, and even more preferably 0.9 to 1.1 moles of carboxyl groups in the unsaturated compound (a2) having a carboxyl group per mole of epoxy groups in the copolymer (a1) having an epoxy group.

[0047] Examples of the catalyst include tetrabutylammonium bromide, tetrabutylammonium chloride, tetramethylammonium bromide, tetramethylammonium chloride, triphenylphosphine, tributylphosphine, 1,8-diazabicyclo[5,4,0]-7-undecene, and 1,4-diazabicyclo[2,2,2]octane. Of these, triphenylphosphine is preferred because it causes less discoloration of the cured product after a weather resistance test.

[0048] The amount of catalyst added is preferably about 0.5 to 5% by weight based on the total amount of the copolymer (a1) having an epoxy group and the unsaturated compound (a2) having a carboxyl group.

[0049] Examples of the organic solvent include ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, etc. When the copolymer (a1) having an epoxy group is in a liquid state, the modification reaction can be carried out without adding an organic solvent.

[0050] A typical method for reacting the copolymer (a1) having a hydroxyl group with the unsaturated compound (a2) having a carboxyl group is a dehydration esterification method, which involves heating a mixture of the copolymer (a1) having a hydroxyl group, the unsaturated compound (a2) having a carboxyl group, a catalyst, and a solvent at 100 to 120°C, and azeotropically dehydrating the organic solvent and the resulting water to allow the reaction to proceed.

[0051] Examples of the catalyst include p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, and sulfuric acid, and the amount of the catalyst used is 0.05 to 5 mol % based on the number of moles of hydroxyl groups to be reacted.

[0052] The organic solvent used is preferably one that has low solubility in the water produced in the dehydration esterification reaction and allows the reaction to proceed while distilling off the water as an azeotrope. Preferred organic solvents include, for example, aromatic hydrocarbons such as toluene, benzene, and xylene; aliphatic hydrocarbons such as hexane, cyclohexane, and heptane; and ketones such as methyl ethyl ketone and cyclohexanone. The proportion of the solvent is preferably 30 to 70% by weight based on the total amount of the reaction solution.

[0053] After the reaction, the acid is generally removed with water or an aqueous alkaline solution.

[0054] As a method of reacting and adding the unsaturated compound (a2) having a hydroxyl group to the copolymer (a1) having an isocyanate group, there can be mentioned a method in which the copolymer (a1) having an isocyanate group and the unsaturated compound (a2) having a hydroxyl group are mixed, and then a curing catalyst such as dibutyltin dilaurate is added as necessary, followed by heating to 60 to 100°C.

[0055] Examples of a method for reacting and adding an unsaturated compound (a2) having a hydroxyl group to a copolymer (a1) having a carboxyl group include a method in which the copolymer (a1) and the unsaturated compound (a2) having a hydroxyl group are mixed, and then a catalyst such as sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, sulfonated polystyrene, or Nafion-H is added, and the mixture is heated to 80 to 120°C, optionally in the presence of an organic solvent such as toluene, to proceed with the esterification reaction while distilling off the water produced. Furthermore, the catalyst remaining after the reaction can be removed by one or a combination of two or more of the following methods: washing with water, alkali neutralization, ion exchange resin, chemical filter for catalyst removal, and filtration.

[0056] In any of the above modification reactions, it is preferable to add a polymerization inhibitor to suppress gelation or to improve the storage stability of the modified product. Examples of the polymerization inhibitor include methoxyphenol, hydroquinone, dibutylhydroxytoluene, etc. From the viewpoint of suppressing coloration of the cured product, it is particularly preferable to use dibutylhydroxytoluene.

[0057] (4) Physical properties of (A1) component (acrylic equivalent and molecular weight) The acrylic equivalent of component (A1) is preferably 3000 g / eq or less. More preferred ranges of the acrylic equivalent of component (A1) are, in order, 150 g / eq to 2500 g / eq, 300 g / eq to 2000 g / eq, 400 g / eq to 1400 g / eq, and 700 g / eq to 1000 g / eq. By ensuring that the acrylic equivalent is 150 g / eq or more, the elongation and flexibility of the cured product can be ensured, and by ensuring that the acrylic equivalent is 3000 g / eq or less, the strength and weather resistance of the cured product can be ensured and a good curing rate can be maintained.

[0058] In the present invention, the acrylic equivalent (g / eq) represents the weight (g) per equivalent (eq) of (meth)acryloyl groups, and the larger the value, the lower the concentration of (meth)acryloyl groups, and the smaller the value, the higher the concentration of (meth)acryloyl groups.

[0059] The acrylic equivalent can be calculated using the following formula: In the formula, the number of moles of (meth)acryloyl groups in component (A1) is the number of moles of (meth)acryloyl groups in unsaturated compound (a2) added to copolymer (a1) in the modification reaction, and does not include (meth)acryloyl groups derived from unreacted unsaturated compound (a2) present after the modification reaction.

[0060]

number

[0061] The molecular weight, Mw, of the component (A1) is preferably from 2,000 to 60,000, and more preferably from 2,000 to 50,000. A Mw of 2,000 or more provides a cured product with excellent weather resistance and tensile properties, while a Mw of 60,000 or less allows for low viscosity even at relatively high concentrations, resulting in excellent coatability and excellent compatibility when mixed with other curable compounds.More preferred ranges for the Mw of component (A1) are 3,000 to 50,000, 3,000 to 40,000, 3,000 to 30,000, and 4,000 to 20,000, in order of preference. The number average molecular weight (hereinafter referred to as "Mn") of the component (A1) is preferably 1,000 to 30,000. An Mn of 1,000 or more provides a cured product with excellent weather resistance and tensile properties, while an Mn of 30,000 or less allows for low viscosity even at relatively high concentrations, resulting in excellent coatability and excellent compatibility when mixed with other curable compounds. More preferred ranges for Mn of component (A1) are 1,500 to 15,000, 2,000 to 10,000, and 2,500 to 7,000, in order of preference. In the present invention, Mn means a value obtained by converting the molecular weight measured by GPC into polystyrene equivalent.

[0062] 1-2. (A2) component As the component (A) of the present invention, in addition to the component (A1), a component (A2) (that is, a compound having an ethylenically unsaturated group other than the component (A1)) can also be used. In the composition of the present invention, when the component (A2) alone exhibits a storage modulus G' (measurement frequency 1 Hz) at 80°C of 10 Pa or more of the dried coating film before irradiation with active energy rays, the component (A) may be solely the component (A2). A preferred embodiment of the composition of the present invention is a composition in which component (A1) and component (A2) are used in combination to reduce the viscosity of the entire composition or to adjust other physical properties, in cases where the viscosity of the composition would be too high if component (A1) alone were used.

[0063] Specific examples of the component (A2) include the monomer (a1-1), the monomer (a1-2), (meth)acrylates other than the monomers (a1-1) and (a1-2) (hereinafter referred to as "other (meth)acrylates"), and N-vinyl-2-pyrrolidone.

[0064] Other (meth)acrylates include compounds having one (meth)acryloyl group (hereinafter referred to as "monofunctional (meth)acrylates") and compounds having two or more (meth)acryloyl groups (hereinafter referred to as "polyfunctional (meth)acrylates").

[0065] Specific examples of monofunctional (meth)acrylates include trimethylcyclohexyl (meth)acrylate, 1-adamantyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, benzyl (meth)acrylate, allyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, o-phenylphenol EO-modified (n=1 to 4) (meth)acrylate, p-cumylphenol EO-modified (n=1 to 4) (meth)acrylate, phenyl (meth)acrylate, o-phenylphenyl (meth)acrylate, p-cumylphenyl (meth)acrylate, N-(meth)acryloylmorpholine, N-vinylformamide, N-(meth)acryloyloxyethyl hexahydrophthalimide, and N-(meth)acryloyloxyethyl tetrahydrophthalimide.

[0066] Specific examples of polyfunctional (meth)acrylates include urethane (meth)acrylates such as urethane acrylates having a polyester skeleton and urethane (meth)acrylates such as urethane acrylates having a polycarbonate skeleton; Di(meth)acrylates having a bisphenol skeleton, such as bisphenol A EO-modified (n=1 to 2) di(meth)acrylate and bisphenol A di(meth)acrylate; (poly)alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol (n=5 to 14) di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol (n=5 to 14) di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, polybutylene glycol (n=3 to 16) di(meth)acrylate, and poly(1-methylbutylene glycol) (n=5 to 20) di(meth)acrylate; Di(meth)acrylates of aliphatic diols such as 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate; Hydroxypivalic acid neopentyl glycol di(meth)acrylate; Di(meth)acrylates having an alicyclic skeleton, such as tricyclodecanedimethylol di(meth)acrylate; (Meth)acrylates having an isocyanurate skeleton, such as EO-modified isocyanuric acid diacrylate and ε-caprolactone-modified tris((meth)acryloxyethyl)isocyanurate; Polyol poly(meth)acrylates such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri- or tetra(meth)acrylate, ditrimethylolpropane tri- or tetra(meth)acrylate, diglycerin tri- or tetra(meth)acrylate, and dipentaerythritol tri-, tetra-, penta-, or hexa(meth)acrylate; and Examples of the alkylene oxide adduct include poly(meth)acrylates of polyol alkylene oxide adducts such as tri(meth)acrylates of glycerin alkylene oxide adducts, tri- or tetra(meth)acrylates of pentaerythritol alkylene oxide adducts, tri- or tetra(meth)acrylates of ditrimethylolpropane alkylene oxide adducts, tri- or tetra(meth)acrylates of diglycerin alkylene oxide adducts, and tri-, tetra-, penta-, or hexa(meth)acrylates of dipentaerythritol alkylene oxide adducts. In the above, EO-modified means ethylene oxide-modified, and n means the number of repeating alkylene oxide units. Among these compounds, urethane (meth)acrylate and (meth)acrylate having an isocyanurate skeleton are preferred as the polyfunctional (meth)acrylate.

[0067] As the component (A2), the above-mentioned compounds may be used alone or in combination of two or more.

[0068] The blending ratio of component (A2) may be set appropriately depending on the purpose, and may be any amount that does not reduce the flexibility of the resulting cured product. The blending ratio is preferably 0 to 70% by weight, more preferably 1 to 60% by weight, and even more preferably 1 to 45% by weight, based on a total of 100% by weight of component (A).

[0069] 2. Actinic energy ray curable composition The active energy ray-curable composition of the present invention contains at least component (A), and the dried coating film before irradiation with active energy rays exhibits a storage modulus G' at 80° C. (measurement frequency 1 Hz) of 10 Pa or more. In the present invention, the dried coating refers to a coating before irradiation with active energy rays. When the composition does not contain a (B) solvent (hereinafter referred to as "component (B)"), this refers to a coating obtained by applying the composition to a substrate. When the composition contains component (B), this refers to a coating obtained by applying the composition to a substrate and then drying it by heating. A composition that satisfies such a storage modulus G' can be produced by appropriately designing the above components that make up component (A) and the various physical properties of those components, and / or by appropriately mixing other components such as component (B) with component (A). Component (A) may be either solid at room temperature or solvent-free liquid at room temperature, but is preferably solid at room temperature. Component (A) that is solid at room temperature can be used by mixing it with component (B) as appropriate. Furthermore, even if it contains other components, it is preferable that the dried coating be solid. Component (A) can be used even if it is a mixture of a solid at room temperature and a solvent-free liquid at room temperature, as long as the overall composition satisfies the storage modulus G'. Also, component (A) can be used even if it is a solvent-free liquid at room temperature, as long as the overall composition satisfies the storage modulus G' by mixing it with other components.

[0070] In the present invention, the storage modulus G' refers to a value determined by measuring the temperature dispersion of dynamic viscoelasticity in shear mode in accordance with JIS K7244-6 (sample thickness: 0.3 mm, strain: 1.0%, measurement frequency: 1 Hz, heating rate: 2°C / min). The storage modulus G' must be 10 Pa or more, preferably 30 Pa or more, and more preferably 100 Pa or more. If the storage modulus G' is 10 Pa or more, dripping is suppressed, and if it is 30 Pa or more, dripping is less likely to occur even when the film thickness is thick, which is preferable. The upper limit of the storage modulus G' is preferably 10,000 Pa. By keeping it within this upper limit, excellent leveling of the coating film and a smooth coating film can be obtained.

[0071] The viscosity of the composition before forming a dried film may be appropriately set depending on the application and purpose of use, etc. The preferred viscosity is 100 to 20,000 mPa·s, and more preferably 200 to 8,000 mPa·s. In the present invention, the viscosity refers to a value measured at 25°C using an E-type viscometer (cone-plate type viscometer). The proportion of the solid component at room temperature relative to the total amount of the composition is preferably 30% by weight or more, more preferably 50% by weight or more.

[0072] The composition of the present invention not only inhibits dripping, but also provides a cured product having excellent tensile properties such as tensile strength and elongation, as well as excellent weather resistance. In terms of tensile properties, the breaking strength is preferably 20 MPa or more, more preferably 30 MPa or more. Next, the elongation is preferably 2% or more, and more preferably 5% or more. The tensile product is preferably 60 MPa or more, more preferably 150 MPa or more, and even more preferably 200 MPa or more. Since breaking strength and elongation are generally in a trade-off relationship, the higher the tensile product (breaking strength × elongation / 2), the better the tensile properties.

[0073] The composition of the present invention essentially contains the component (A), but as described above, the component (B) and various other components can be blended as needed. An example of a component other than component (B) that can be added is a photoradical polymerization initiator (hereinafter also referred to as "component (C)"). Components (B) and (C) and other components will be described below.

[0074] 2-1. (B) component The composition of the present invention may contain a solvent as component (B) for the purpose of improving the coating properties on the substrate. Examples of the component (B) include organic solvents and water, with organic solvents being preferred. The organic solvent and water will be described below.

[0075] (1) Organic solvent Even if the organic solvent is the same compound, it is referred to as an "organic solvent" when used in a reaction system, and as an "organic solvent" when used in a composition such as a paint; in the present invention, these are collectively referred to as "organic solvent."

[0076] Specific examples of the organic solvent include hydrocarbon solvents such as n-hexane, benzene, toluene, xylene, ethylbenzene, and cyclohexane; alcoholic solvents such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, 2-methoxyethanol, 2-ethoxyethanol, 2-(methoxymethoxy)ethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2-isopentyloxyethanol, 2-hexyloxyethanol, 2-phenoxyethanol, 2-benzyloxyethanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and propylene glycol monomethyl ether; ether solvents such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, bis(2-methoxyethyl) ether, bis(2-ethoxyethyl) ether, and bis(2-butoxyethyl) ether; ketone solvents such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, diethyl ketone, butyl methyl ketone, methyl isobutyl ketone, methyl pentyl ketone, di-n-propyl ketone, diisobutyl ketone, phorone, isophorone, cyclopentanone, cyclohexanone, and methylcyclohexanone; ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, methyl glycol acetate, propylene glycol monomethyl ether acetate, and cellosolve acetate; Examples of the aprotic polar solvent include N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and γ-butyrolactone.

[0077] As the organic solvent, one or more of the above-mentioned compounds can be used. The organic solvent may be added separately to dilute the component (A), or the organic solvent used in the production of the component (A) may be used as is without separation.

[0078] The blending ratio of the organic solvent may be set appropriately taking into consideration the viscosity of the composition, the intended use, etc., but is preferably 70% by weight or less, more preferably 60% by weight or less, even more preferably 50% by weight or less, even more preferably 40% by weight or less, and particularly preferably 15 to 40% by weight, based on 100% by weight of the total of components (A) and (B).

[0079] (2) Water The composition of the present invention may contain water as component (B). When water is contained as component (B), a composition in which component (A) is dispersed in water is preferred. The method for dispersing component (A) in water (hereinafter also referred to as "water-based dispersion") may be performed in accordance with conventional methods.

[0080] In the production of the component (A1), when the reaction between the copolymer (a1) and the unsaturated compound (a2) is carried out in an organic solvent, an example of a method is to subsequently carry out aqueous conversion to obtain an aqueous dispersion of the component (A1). A more specific method for making the component (A1) aqueous-based includes adding water and a surfactant (dispersant) to the organic solvent solution of component (A1) obtained by the above reaction, stirring and mixing to disperse component (A1) in water, and then removing the organic solvent by heating under reduced pressure.

[0081] Another method for making the component (A1) aqueous is to add water and a surfactant to the component (A1) that has been isolated in advance, and then stir the mixture. When component (A1) is a mixed liquid containing an organic solvent, the organic solvent is generally removed by heating under reduced pressure or by distillation, as described above.

[0082] Furthermore, if component (A1) (or its organic solvent mixture) is insoluble in water, adding water and a surfactant may result in the component (A1) precipitating, making it impossible to maintain the uniformity of the system and resulting in a homogeneous dispersion. In such a case, a water-soluble organic solvent may be added before or simultaneously with the addition of water and a surfactant to form an aqueous dispersion, and then the water-soluble organic solvent may be removed by distillation.

[0083] As the surfactant, various emulsifiers such as anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, and zwitterionic emulsifiers can be used, and among these, nonionic surfactants are particularly preferred. The surfactant is preferably added in an amount of 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight, and even more preferably 2 to 7 parts by weight, in terms of the pure surfactant content, per 100 parts by weight of the total amount of component (A).

[0084] Examples of water-soluble organic solvents include alkyl alcohols having 1 to 4 carbon atoms, ketones or keto alcohols, polyalkylene glycols, alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms, lower alkyl ethers, pyrrolidones, and 1,3-dimethyl-2-imidazolidinone.

[0085] 2-2. (C) component When ultraviolet light and visible light are used as the active energy rays, the composition of the present invention may contain component (C) (photopolymerization initiator). When electron beams are used as the active energy rays, it is not always necessary to incorporate component (C), but a small amount of component (C) can be incorporated as needed to improve curability.

[0086] Component (C) includes benzil dimethyl ketal, benzil, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, oligo[2-hydroxy-2-methyl-1-[4-1-(methylvinyl)phenyl]propanone, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propan-1-one] ... aromatic ketone compounds such as 2-methyl-1-[4-(methylthio)]phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)butan-1-one, ADEKA Optomer N-1414 (manufactured by ADEKA Corporation), phenylglyoxylic acid methyl ester, ethyl anthraquinone, and phenanthrenequinone; benzophenone-based compounds such as benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 4-(methylphenylthio)phenylphenylmethane, methyl-2-benzophenone, 1-[4-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone; Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl-(2,4,6-trimethylbenzoyl)phenylphosphinate and bis(2,6-dimethoxybenzo) acylphosphine oxide compounds such as (methyl)-2,4,4-trimethylpentylphosphine oxide; Thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propylthioxanthone, 3-[3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl]oxy]-2-hydroxypropyl-N,N,N-trimethylammonium chloride, and fluorothioxanthone; acridone compounds such as acridone and 10-butyl-2-chloroacridone; Oxime esters such as 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzoyloxime)] and ethanone 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime); 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-phenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer and 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer; and Examples include acridine derivatives such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane.

[0087] These compounds can be used alone or in combination of two or more.

[0088] The blending ratio of the component (C) is preferably 0.01 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the total amount of the component (A). By setting the blending ratio of component (C) to 0.01 parts by weight or more, the composition can be cured with an appropriate amount of ultraviolet or visible light, improving productivity, while by setting the blending ratio to 10 parts by weight or less, the cured product can be made to have excellent weather resistance and transparency.

[0089] 2-3. Other components other than the above As other components other than those mentioned above, various components can be blended depending on the purpose. When the composition of the present invention is used as a coating agent, examples of additives that can be used include polymerization inhibitors and / or antioxidants, light resistance improvers, inorganic particles, surface modifiers, pigments, dyes, and tackifiers. Among the other components, the polymerization inhibitor and / or antioxidant, and the light resistance improver will be described below.

[0090] <Polymerization inhibitor or / and antioxidant> The active energy ray-curable composition of the present invention may contain a polymerization inhibitor and / or an antioxidant in order to improve storage stability. The polymerization inhibitor is preferably hydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol, or various phenol-based antioxidants, but may also be a sulfur-based secondary antioxidant, a phosphorus-based secondary antioxidant, or the like.

[0091] The total amount of these polymerization inhibitors and / or antioxidants added is preferably 0.001 to 3 parts by weight, and more preferably 0.01 to 0.5 parts by weight, per 100 parts by weight of the total amount of component (A).

[0092] <Light resistance improver> The active energy ray-curable composition of the present invention may contain a light resistance improver such as an ultraviolet absorber or a light stabilizer.

[0093] Examples of ultraviolet absorbers include benzotriazole compounds such as 2-(2'-hydroxy-5-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)benzotriazole; Triazine compounds such as 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-s-triazine; Examples of the benzophenone compounds include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-benzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3',4,4'-tetrahydroxybenzophenone, and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone.

[0094] Examples of the light stabilizer include hindered amine light stabilizers such as low molecular weight hindered amine compounds such as N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-N,N'-diformylhexamethylenediamine, bis(1,2,6,6-)pentamethyl-4-piperidyl)-2-(3,5-ditertiarybutyl-4-hydroxybenzyl)-2-n-butylmalonate, and bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate; and high molecular weight hindered amine compounds such as N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-N,N'-diformylhexamethylenediamine and bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate.

[0095] The amount of the light resistance improver added is preferably 0 to 5 parts by weight, and more preferably 0 to 1 part by weight, per 100 parts by weight of the total amount of the component (A).

[0096] 3. Usage method The active energy ray-curable composition of the present invention can be used in various ways depending on the purpose. For example, when the composition of the present invention is used as a coating agent, the composition is applied to a substrate, and if an organic solvent is contained in the composition, the organic solvent in the composition is evaporated by heating, and then the composition is cured by irradiating with active energy rays. Furthermore, when the composition of the present invention is used as an adhesive, a method can be used in which the composition is applied to a substrate, and if an organic solvent is contained in the composition, the organic solvent in the composition is evaporated by heating, and then the composition is bonded to another substrate, and then further cured by irradiation with active energy rays.

[0097] The composition of the present invention can be applied to a variety of substrates, including inorganic materials, plastics, and paper. Examples of inorganic materials include glass, metal, mortar, concrete, and stone. Examples of metals include steel plates, metals such as aluminum and chromium, and metal oxides such as zinc oxide (ZnO) and indium tin oxide (ITO). Specific examples of plastics include polyolefins such as polyethylene and polypropylene, ABS resin, polyvinyl alcohol, cellulose acetate resins such as triacetyl cellulose and diacetyl cellulose, acrylic resin, polyethylene terephthalate (hereinafter referred to as "PET resin"), polycarbonate, polyarylate, polyethersulfone, cyclic polyolefin resins containing cyclic olefins as monomers such as norbornene, polyvinyl chloride, epoxy resin, polyurethane resin, etc. Thermoplastic plastics are preferred, and specific examples thereof include PET resin, acrylic resin, ABS resin, polycarbonate, polypropylene, polyethylene, etc., with PET resin being preferred. Of these materials, metals and plastics are preferred as the substrate. The shape of the substrate is not particularly limited, and may be any of a sheet, a film, a plate, and the like.

[0098] The method for applying the composition may be appropriately selected depending on the purpose, and examples thereof include coating methods using conventionally known bar coaters, applicators, doctor blades, knife coaters, comma coaters, reverse roll coaters, die coaters, lip coaters, gravure coaters, and microgravure coaters.

[0099] When the composition of the present invention contains an organic solvent, it is preferable that after coating on a substrate, the composition be heated and dried to evaporate the organic solvent. The drying temperature is not particularly limited as long as it is a temperature below which the substrate to be applied does not suffer from problems such as deformation. A preferred heating temperature is 40 to 100° C. The drying time may be appropriately set depending on the substrate to be applied and the heating temperature, and is preferably 0.5 to 20 minutes.

[0100] The thickness of the cured film of the composition on the substrate may be appropriately set depending on the purpose. The thickness of the cured film may be selected depending on the substrate to be used and the application of the substrate having the produced cured film, but is preferably 1 to 100 μm, more preferably 2 to 40 μm.

[0101] Examples of the active energy ray used to cure the active energy ray-curable composition of the present invention include electron beams, ultraviolet rays, and visible light. Of these, ultraviolet light is preferred because it can be cured using a relatively simple device and can be cured in a short time with low energy irradiation. Electron beam irradiation is preferred because it does not necessarily require the addition of component (C) (photopolymerization initiator) and the cured product has excellent weather resistance. Examples of ultraviolet irradiation devices include high-pressure mercury lamps, metal halide lamps, ultraviolet (UV) electrodeless lamps, and light-emitting diodes (LEDs).

[0102] The irradiation conditions for the active energy ray irradiation, such as the dose, irradiation amount, and irradiation intensity, may be appropriately selected depending on the composition used, the substrate, the purpose, and the like. As an example of using ultraviolet light, when using a high-pressure mercury lamp, the irradiation energy in the UV-A region is 100 to 8,000 mJ / cm 2 is preferred, and 200 to 3,000 mJ / cm 2 is more preferred. When an electron beam is used, it is preferable to irradiate at an acceleration voltage of 50 to 300 kV and with an absorbed dose of 10 to 1,000 kGy.

[0103] The composition of the present invention can be used in a variety of applications. Specific examples thereof include coating agents, adhesives, inks, and films, and the material can be preferably used as a coating agent. Specific applications of the coating agent include various paints, decorative films, and top coating agents for various substrates. More specific applications of the coating agent include hard coating applications, in which the substrate includes plastic films used in polarizer protective films and antireflection films, and resin molded products used in home appliances and automobile interior and exterior parts. Other uses of the coating agent include its use as a coating agent for inorganic substrates such as concrete, or wood, and its use in coating exterior walls and construction materials in civil engineering and building applications. Other uses of the coating agent include its preferred use as a coating agent for metal substrates, and it can be used as an electrode protective coating agent for PDPs (plasma display panels), a substrate circuit protective material for electric bicycles, an electrode protective coating agent for lithium-ion batteries, etc., and a coating agent for automobile interior and exterior components. [Example]

[0104] The present invention will be described in more detail below with reference to examples and comparative examples. In the following, "parts" means parts by weight. In the Production Examples and Working Examples, the molecular weight, Tg, acid value, solid content, and viscosity were measured according to the following methods.

[0105] <Measurement of molecular weight> Using a gel permeation chromatograph (model HLC-8320, manufactured by Tosoh Corporation), polystyrene-equivalent Mw (weight average molecular weight) and Mn (number average molecular weight) were obtained under the following conditions. Measurement conditions Column: Tosoh Corporation TSKgel SuperMultiporeHZ-M x 4 Column temperature: 40℃ Eluent: tetrahydrofuran Detector: RI

[0106] <Measurement of Tg> The Tg of the copolymer (a1) was measured by a differential scanning calorimeter (DSC) under the following conditions. Measurement conditions DSC: TA Instrument (Q-100) Temperature rise: 10°C / min Measurement atmosphere: Nitrogen

[0107] <Measurement of acid value> The acid value measurement was carried out in accordance with JIS K0070. Specifically, a sample was weighed so that the titration volume was approximately 10 mL, and diluted with approximately 50 mL of tetrahydrofuran. Then, titration was carried out using an automatic titrator COM-1600ST (manufactured by Hiranuma Sangyo Co., Ltd.) with a 0.1 N KOH / ethanol solution as the titrant.

[0108] <Solid content> The solid content was determined from the weight loss after drying in a forced air dryer at 150°C for 1 hour.

[0109] <Acrylic equivalent> The weight (g) of the raw materials used excluding the organic solvent component was divided by the number of moles of the compound having a reactive group and a (meth)acryloyl group used, and the value was taken as the acrylic equivalent (g / eq).

[0110] 1. Production example (1) Production example 1 The temperature of a 1000 mL oil-jacketed pressurized stirred tank reactor was maintained at 188°C. Next, while maintaining the pressure of the reactor constant, a monomer mixture consisting of 70 parts of methyl methacrylate (hereinafter referred to as "MMA"), 10 parts of ethyl acrylate (hereinafter referred to as "EA"), 20 parts of glycidyl methacrylate (hereinafter referred to as "GMA"), 12 parts of methyl ethyl ketone (hereinafter referred to as "MEK") as a solvent, 3 parts of trimethyl orthoacetate (manufactured by Nippoh Chemical Industries, Ltd., trade name "MOA", hereinafter referred to as "MOA"), and 1 part of di-t-hexyl peroxide (manufactured by NOF Corp., trade name "Perhexyl D", hereinafter referred to as "DTHP") as a polymerization initiator was continuously fed from a raw material tank to the reactor at a constant feed rate (48 g / min, residence time: 12 min), and a reaction liquid equivalent to the amount of the monomer mixture fed was continuously withdrawn from the outlet. Immediately after the start of the reaction, the reaction temperature dropped once, and then a temperature rise due to the heat of polymerization was observed, but the reaction temperature was maintained at 187 to 189°C by controlling the temperature of the oil jacket.

[0111] The point at which the temperature stabilized after the start of the monomer mixture supply was designated the start point for collecting the reaction solution, and the reaction was continued for 37 minutes from this point. As a result, 1.78 kg of the monomer mixture was supplied and 1.78 kg of the reaction solution was collected. The reaction solution was then introduced into a thin-film evaporator, and volatile components such as unreacted monomers were separated, yielding 1.08 kg of a (meth)acrylate polymer having an epoxy group (hereinafter referred to as "copolymer a1-1"). Table 1 shows the polystyrene-equivalent Mw and Tg of copolymer a1-1.

[0112] Next, copolymer a1-1 (100 parts), dibutylhydroxytoluene (hereinafter referred to as "BHT") (0.11 parts) as a polymerization inhibitor, acrylic acid (hereinafter referred to as "AA") (11.2 parts, corresponding to an acid value of 1.05 equivalents of the epoxy group of copolymer a1-1) as unsaturated compound (a2), and butyl acetate (47.9 parts) as an organic solvent were charged into a 1 L flask, and the liquid temperature was raised to 95°C while bubbling a 5% oxygen-nitrogen mixed gas, to dissolve copolymer a1-1. After uniform dissolution, triphenylphosphine (hereinafter referred to as "TPP") (0.56 parts) was added as a reaction catalyst, and the mixture was stirred for 12 hours while maintaining the internal temperature at 95°C. Further TPP (0.56 parts) was added, and the reaction was continued for 12 hours. Thereafter, the acid value was measured, and it was confirmed to be 3.6 mgKOH / g, and the reaction was terminated. As a result, a butyl acetate solution containing polymer A-1, which was an AA adduct of copolymer a1-1, was obtained.

[0113] Table 2 shows the solid content, acid value, Mn, Mw, and acrylic equivalent (g / eq) calculated in terms of polystyrene of the polymer A-1 solution.

[0114] (2) Production examples 2 to 9, Comparative production example 1 Except for changing the conditions as shown in Table 1, the same procedure as in Production Example 1 was carried out to obtain (meth)acrylate polymers A-2 to A-9 and A'-1 having an acryloyl group in the side chain. In addition, M5300 in Table 1 is as defined below.

[0115] (3) Production example 10 A (meth)acrylic polymer having an isocyanate group (hereinafter referred to as "copolymer a1-8") was obtained by the same procedure as in Production Example 1, except that the conditions were changed as shown in Table 1. The MOI in Table 1 is as defined below. Then, copolymer a1-8 (100 parts), dibutylhydroxytoluene (0.12 parts) as a polymerization inhibitor, 2-hydroxyethyl acrylate (hereinafter referred to as "HEA") (24.7 parts, corresponding to a hydroxyl value of 1.0 equivalent of the isocyanate group of polymer a1-8), dibutyltin dilaurate (0.03 parts) as a catalyst, and butyl acetate (64.3 parts) were placed in a 1 L flask, and the liquid temperature was raised to 80°C while bubbling a 5% oxygen-nitrogen mixed gas, to dissolve copolymer a1-8. The mixture was stirred for 6 hours while maintaining the temperature at 80°C, and the IR spectra were measured at 2200 cm using an ATR infrared spectrophotometer (Spectrum 100, manufactured by Perkin Elmer). -1The reaction was terminated after confirming that the absorption by isocyanate in the copolymer a1-8 had disappeared. As a result, a butyl acetate solution containing polymer A-10, which was an HEA adduct (acrylate-modified product) of copolymer a1-8, was obtained.

[0116] (4) Production example 11 Polymer A-11, which is an FA-2D adduct (acrylate modified product) of copolymer a1-8, was obtained by the same procedure as in Production Example 10, except that the conditions were changed as shown in Table 1. In addition, FA-2D in Table 1 is as defined below.

[0117] [Table 1]

[0118] The abbreviations in Table 1 have the following meanings. Note that, in the following, some of the abbreviations already defined above are repeated. MMA: Methyl methacrylate BA: Butyl acrylate EA: Ethyl acrylate GMA: Glycidyl methacrylate MOI: 2-isocyanate ethyl methacrylate (Karenz MOI (trade name), manufactured by Showa Denko K.K.) MEK: Methyl ethyl ketone MOA: Trimethyl orthoacetate (MOA (trade name), manufactured by Nippoh Chemical Industries, Ltd.) DTHP: Di-t-hexyl peroxide (Perhexyl D (trade name), manufactured by NOF Corp.)

[0119] [Table 2]

[0120] The abbreviations in Table 2 have the following meanings. Note that, in the following, some of the abbreviations already defined above are repeated. AA: Acrylic acid M5300: ε-caprolactone adduct of acrylic acid (Aronix M-5300 (trade name), manufactured by Toagosei Co., Ltd., average degree of polymerization of caprolactone: 2, number average molecular weight: 300, Tg: -78°C, acid value: 186 mgKOH / g) HEA: 2-hydroxyethyl acrylate FA-2D: ε-caprolactone adduct of 2-hydroxyethyl acrylate (Placcel FA2D (trade name), manufactured by Daicel Corporation, average degree of polymerization of caprolactone: 2, number average molecular weight: 344, Tg: -78°C, hydroxyl value: 163 mgKOH / g) TPP: Triphenylphosphine DBTDL: Dibutyltin dilaurate BHT: Dibutylhydroxytoluene

[0121] 2. Examples 1 to 14, Comparative examples 1 to 2 (UV curable composition) The raw materials shown in Table 3 were used and stirred and mixed according to the ratios shown in Table 3 to prepare ultraviolet-curable compositions, which were then evaluated as follows. The results are shown in Table 3.

[0122] (1) Measurement of storage elastic modulus G' before irradiation For the composition containing an organic solvent, tape was attached to both ends of a polyester film (manufactured by Mitsubishi Chemical Corporation, trade name: MRV-75, film thickness 75 μm, hereinafter referred to as MRV-75), and the coating was applied using a bar coater #0 to a thickness of 80 to 120 μm, followed by drying in a forced air dryer at 90°C for 10 minutes. Three to four of these samples were stacked and then pressed with MRV-75 film from both sides at 90°C to obtain a sample with a thickness of approximately 300 μm. The compositions containing no organic solvent were used as they were for the measurements. *In Comparative Examples 1 and 2 in Table 3, 20 parts of butyl acetate is listed, but the measurement of storage modulus and evaluation of dripping were performed without adding butyl acetate. All other evaluations were performed by adding butyl acetate as shown in Table 3.

[0123] (Measurement conditions) Apparatus: Rheometer MCR-301 (manufactured by Anton Paar) Measurement frequency: 1Hz Measurement temperature: -30~100℃ Heating rate: 2°C / min Measurement was carried out under the above conditions, and the storage modulus G' at 80°C was determined.

[0124] (2) Evaluation of unirradiated objects (before curing) (2-1) Evaluation of dripping The liquid was applied to a chromate-treated aluminum plate using a bar coater #30 (less than 30 parts of organic solvent) or #40 (30 parts or more of organic solvent) so that the film thickness after drying would be approximately 30 μm. After leaving it to stand for 5 minutes, the coated plate was held vertically and dried in a forced air dryer at 80°C for 10 minutes. Thereafter, the presence or absence of dripping was confirmed visually.

[0125] (2-2) Evaluation of tack and pencil hardness The liquid was applied to a chromate-treated aluminum plate using a bar coater #30 (less than 30 parts of organic solvent) or #40 (30 parts or more of organic solvent) so that the film thickness after drying would be approximately 30 μm. After leaving it to stand for 5 minutes, the coated plate was placed horizontally and dried in a forced air dryer at 90°C for 10 minutes. The presence or absence of tack was then evaluated by touch using a finger according to the following criteria. Evaluation criteria 〇: No tuck △: Tacky but not sticky to fingers ×: Sticks to fingers The surface of the coating was scratched with a pencil under a load of 750 g, and the hardness of the hardest pencil that did not leave a scratch was recorded as the pencil hardness.

[0126] (3) Evaluation of physical properties of cured products (UV curing system) (3-1) Evaluation of pencil hardness (UV curing system) The composition was applied to a chromate-treated aluminum plate using a bar coater #30 (less than 30 parts of organic solvent) or #40 (30 parts or more of organic solvent) so that the film thickness after drying would be 30 to 40 μm, and then dried in a forced air dryer at 90°C for 10 minutes. Next, a high-pressure mercury lamp manufactured by Eye Graphics Co., Ltd. was used in an air atmosphere, with a focused UVA irradiance of 500 mW / cm. 2 , the irradiation dose per time is 800mJ / cm 2 The coated film was passed twice under the light irradiation on a conveyor. The surface of the coating was scratched with a pencil under a load of 750 g, and the hardness of the hardest pencil that did not leave a scratch was recorded as the pencil hardness.

[0127] (3-2) Evaluation of tensile physical properties Lumirror T-60 (product name, PET film manufactured by Toray Industries, Inc., film thickness: 100 μm) was prepared as a base film, tape was attached to both ends of the film, and the ultraviolet-curable compositions obtained in the above Examples and Comparative Examples were applied to the surface of the base film using a bar coater #0 so that the film thickness after drying would be 60 to 80 μm. The film was then dried in a forced air dryer at 90°C for 10 minutes to obtain a coated film having a dried coating film of the composition. Next, a high-pressure mercury lamp manufactured by Eye Graphics Co., Ltd. was used in an air atmosphere, with a focused UVA irradiance of 500 mW / cm. 2 , the irradiation dose per time is 800mJ / cm 2 The coated film was passed twice under the light irradiation on a conveyor. Next, the film having the cured film was cut into strips having a width of 1 cm, and then the cured film was peeled off from the substrate film. The breaking elongation (%) and breaking strength (unit: MPa) of this cured film were measured using a tensile tester (Autograph AGS-J, manufactured by Shimadzu Corporation) at a tensile speed of 5 mm / min. The tensile product was calculated using the following formula. Tensile product = Breaking strength x Elongation / 2

[0128] (3-3) Evaluation of weather resistance Zeono ZF14-100 (trade name, cycloolefin polymer manufactured by Zeon Corporation, film thickness: 100 μm) was prepared as a base film, tape was attached to both ends of the film, and the ultraviolet-curable compositions obtained in the above Examples and Comparative Examples were applied to the surface of the base film using a bar coater #0 so that the film thickness after drying would be 50 to 60 μm. The film was then dried in a forced air dryer at 90°C for 10 minutes to obtain a coated film having a dried coating film of the composition. Next, a high-pressure mercury lamp manufactured by Eye Graphics Co., Ltd. was used in an air atmosphere, with a focused UVA irradiance of 500 mW / cm. 2 , the irradiation dose per time is 800mJ / cm 2 The coated film was passed twice under the light irradiation on a conveyor. The resulting cured film was placed in a metal weather meter (Daipla Wintes Co., Ltd., "DAIPLA METAL WEATHER KU-R5NCI-A" (trade name)) and subjected to an accelerated weathering test. The irradiation conditions were 63°C, 70% RH, and an illuminance of 80 mW / cm. 2 The test was conducted for 300 hours, with a two-minute shower once every two hours. The evaluation was based on the color difference and haze before and after the test.

[0129] <Measurement of color difference> The yellowness index (YI) was measured using a spectrophotometer SE-2000 (trade name) manufactured by Nippon Denshoku Industries Co., Ltd. (YI is calculated using the following formula). ΔYI is preferably 3.5 or less. YI = 100(1.28X-1.06Z) / Y (X, Y, Z are color coordinates) ΔYI = YI-YI0 (YI0 indicates YI before the accelerated weathering test)

[0130] <Measurement of haze> The difference in haze (Δ haze) before and after the accelerated weathering test was measured using NDH2000 (trade name) manufactured by Nippon Denshoku Industries Co., Ltd. The Δ haze is preferably 2.0 or less.

[0131] [Table 3]

[0132] The abbreviations in Table 3 have the following meanings. M1200: Polyester-based urethane acrylate (Mw=4,500) [Aronix M-1200 (product name), manufactured by Toagosei Co., Ltd.] M5300: ε-caprolactone adduct of acrylic acid (Aronix M-5300 (trade name), manufactured by Toagosei Co., Ltd., average degree of polymerization of caprolactone: 2, number average molecular weight: 300, Tg: -78°C, acid value: 186 mgKOH / g) Omnirad184: 1-Hydroxycyclohexyl-phenyl ketone (Omnirad184 (trade name), manufactured by IGM Resins BV)

[0133] The results in Table 3 reveal the following: <Evaluation of dry film (uncured product)> The compositions of Comparative Examples 1 and 2 produced dried films with an 80°C storage modulus G' of less than 1 Pa, resulting in dripping. On the other hand, the compositions of Examples 1 to 14 produced dried films with an 80°C storage modulus G' of 10 Pa or more, resulting in no dripping. Furthermore, the tack and pencil hardness of the dried films of Examples 1 to 14 were also excellent, and even if unirradiated or under-irradiated areas were produced, this did not pose a major problem. Furthermore, compared to compositions containing, as component (A), component (A1) that is solid at room temperature and component (A2) (M-1200, M-5300) that is liquid at room temperature, as in Examples 4, 6, and 7, compositions containing, as component (A), only component (A1) that is solid at room temperature (polymer A-3, polymer A-4) as component (A), as in Examples 3 and 5, had superior tack and pencil hardness.

[0134] <Evaluation of cured product> As in Examples 1, 3, and 4, compositions using copolymers (A-2, A-4) to which an unsaturated double bond-containing oligomer (a2-1) such as M5300 having a Tg of −30 to −90°C as component (A1) was added as component (A1) were superior in tensile properties (especially elongation) to compositions using copolymers (A-1, A-3) to which a low-molecular-weight compound such as acrylic acid was added as component (A1). Regarding the molecular weight of the (A1) component, a comparison between Examples 8, 5, 9, and 10 shows that Example 5 has the optimum tensile properties, whereas higher molecular weights tend to improve weather resistance. With regard to the acrylic equivalent of the (A1) component, a comparison between Examples 11, 5, and 12 reveals that, in terms of tensile properties, the lower the acrylic equivalent, the higher the breaking strength, and the higher the acrylic equivalent, the higher the elongation, and that a lower acrylic equivalent is better for weather resistance.

[0135] 3. Examples 15 to 28, Comparative examples 3 to 4 (Electron beam curable composition) The raw materials shown in Table 4 were used and stirred and mixed in the amounts shown in Table 4 to prepare electron beam curable compositions. Tape was attached to both ends of a smooth glass plate, and the electron beam curable compositions obtained in the above Examples and Comparative Examples were applied using a bar coater #0 so that the film thickness after drying would be 60 to 80 μm. The film was then dried in a forced air dryer at 90°C for 10 minutes to obtain a coated film having a dried coating film of the composition. The coated film was then irradiated with electron beams using an electron beam irradiation device manufactured by NHV Corporation under conditions of an acceleration voltage of 150 kV, a dose of 150 kGy (adjusted by beam current and transport speed), and an oxygen concentration of 300 ppm or less, to obtain a cured product. The cured product was peeled from the glass plate, and the pencil hardness, tensile properties, and weather resistance of the cured product were evaluated in the same manner as in Examples 1 to 14. The results are shown in Table 4. The abbreviations in Table 4 are the same as in Table 3. The electron beam curable composition showed the same tendency as the ultraviolet ray curable composition, but it can be seen that the electron beam curable composition tends to be better in terms of weather resistance.

[0136] [Table 4] [Industrial Applicability]

[0137] The active energy ray-curable composition of the present invention can give a well-cured cured product having a desired shape even when applied to a vertical surface or an object having a complex shape, and therefore can be used in fields where a cured product having excellent design properties, mechanical properties, and weather resistance is required, and can be particularly suitably used in the field of coating agents.

Claims

1. An active energy ray-curable composition comprising (A) a compound having an ethylenically unsaturated group (hereinafter referred to as “component (A)”), the component (A) contains (A1) a (meth)acrylate polymer having an ethylenically unsaturated group in a side chain (hereinafter referred to as “component (A1)”); the component (A1) is a reaction product of a copolymer (a1) (hereinafter referred to as "copolymer (a1)") containing a structural unit derived from a (meth)acrylate monomer (a1-1) having no reactive group and a structural unit derived from a (meth)acrylate monomer (a1-2) having a reactive group selected from the group consisting of an epoxy group, a carboxyl group, a hydroxyl group, and an isocyanate group, and a compound (a2) (hereinafter referred to as "unsaturated compound (a2)") having a group reactive with the reactive group and an ethylenically unsaturated group, The glass transition temperature (Tg) of the copolymer (a1) is 0°C or higher and 90°C or lower, the acrylic equivalent of the component (A1) is 3000 g / eq or less, the unsaturated compound (a2) is an unsaturated double bond-containing oligomer (a2-1) having a glass transition temperature (Tg) of −30 to −90° C., The active energy ray-curable composition has a storage modulus G' (measured at a frequency of 1 Hz) at 80°C of 10 Pa or more when the composition is dried and film-formed before being irradiated with active energy rays.

2. The active energy ray-curable composition according to claim 1 , further comprising (B) a solvent.

3. The active energy ray-curable composition according to claim 1 or 2, wherein the component (A) comprises the following component (A2): Component (A2): a compound having an ethylenically unsaturated group other than component (A1)

4. The active energy ray-curable composition according to any one of claims 1 to 3, wherein the active energy ray is an electron beam.

5. The active energy ray-curable composition according to any one of claims 1 to 4, further comprising (C) a photopolymerization initiator.

6. An active energy ray-curable composition for coating agents, comprising the composition according to any one of claims 1 to 5.

Images