Active energy ray curable composition, cured coating film, and hard coat film

Abstract

The present invention provides an active energy ray curable composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate, a cured coating film using the same, and a hard coat film. [Solution] An active energy ray curable composition comprising: (A) Component: inorganic fine particles; (B) Component: polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and the Tg of the polymer when homopolymerized is 0°C or less; (C) Component: polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains, wherein the content of oxyethylene groups in the solid content of the active energy ray curable composition is 14 to 30% by mass.

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable composition, a cured coating film, and a hard coat film. [Background technology]

[0002] With the rapid development of various display devices (liquid crystal displays, plasma displays, etc.), various projector devices (OHPs (overhead projectors), liquid crystal projectors, etc.), optical fiber communication devices (optical waveguides, optical amplifiers, etc.), and imaging devices such as cameras and video cameras, there is a growing demand for optical components used in these devices that have new functions and are of higher quality. Materials for optical components require properties tailored to various applications. For example, various resin films are used on the surface of liquid crystal displays, but since the surface of resin films is soft and has low scratch resistance, it is common practice to apply a hard coating layer to the film surface to compensate for this. Specifically, a hard coating agent consisting of an active energy ray curable composition is applied to the film surface and dried, and the hard coating agent is cured by irradiation with active energy rays such as ultraviolet light to provide a hard coating layer.

[0003] Hard coat layers used in optical components require high hardness to provide scratch resistance. Generally, it is known that the hardness of the hard coat layer can be increased by improving the crosslinking density using polyfunctional monomers (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-006897 [Overview of the project] [Problems that the invention aims to solve]

[0005] In recent years, flexible displays, which are repeatedly bent and used in various display devices, have become increasingly popular. Flexible displays include foldable displays, which are displays that can be folded, and rollable displays, which are displays that can be rolled into a cylindrical shape, and are incorporated into portable electronic devices such as smartphones and tablet terminals. The hard coat film used in flexible displays is required to have not only scratch resistance, but also a high recovery rate to prevent marks (bending marks) and cracks from occurring when the display is folded while open, and high elasticity to prevent pressure marks from being caused by touch or operation with a stylus.

[0006] However, in general hard coat films such as those described in Patent Document 1, there is a trade-off relationship between recovery rate and elastic modulus. That is, if a film is made with increased flexibility to achieve a superior recovery rate, the elastic modulus tends to decrease, and if a film is made with increased hardness to achieve a superior elastic modulus, the recovery rate tends to decrease.

[0007] The present invention was made to solve the above-mentioned problems, and aims to provide an active energy ray curable composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate, a cured coating film using the same, and a hard coat film. [Means for solving the problem]

[0008] The present inventors conducted diligent studies to solve the above problems and found that an active energy ray curable composition containing inorganic fine particles, a polyfunctional (meth)acrylate having an alkylene glycol skeleton of a specific molecular weight and a polymer Tg of 0°C or less when homopolymerized, and a polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains, with a specific oxyethylene group content, can be obtained to produce a cured coating film that achieves both excellent elastic modulus and recovery rate, thus completing the present invention.

[0009] In other words, the present invention encompasses the following embodiments. [1] Component (A): Inorganic fine particles (B) Component: A polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more and a polymer Tg of 0°C or less when homopolymerized (C) Component: A polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and a (meth)acryloyl group in the side chain An active energy ray-curable composition containing The content of the oxyethylene group in the solid content of the active energy ray-curable composition is 14 to 30% by mass Active energy ray-curable composition [2] (D) Component: Further containing a polyfunctional (meth)acrylate having a (meth)acryloyl group concentration of 7.0 mmol / g or more, and the content of the (D) component in the solid content of the active energy ray-curable resin composition is 0.5 to 10% by mass. The active energy ray-curable composition according to [1]. [3] The (C) component is a compound represented by the following formula (3), or a compound having a branched structure in the polysiloxane skeleton due to condensation of the siloxane sites of the compounds represented by the following formula (3). The active energy ray-curable composition according to [1] or [2]. [Chemical formula] (In formula (3), R 7 each independently represents a hydrogen atom, an alkyl group, or a phenyl group, and R 8 each independently represents a hydrogen atom or a (meth)acryloyl group, and at least two of the n R 8 are (meth)acryloyl groups, and Q 1 each independently represents an optionally substituted alkylene group, an optionally substituted alkenylene group, or an optionally substituted phenylene group. n represents an integer of 2 or more.) [4] The active energy ray-curable composition according to any one of [1] to [3] for forming a hard coat film for a flexible display A cured coating film which is a cured reaction product of an active energy ray curable composition described in any of [5][1] to [4]. A hard coat film comprising the cured coating film and substrate described in [6][5], wherein the thickness of the cured coating film is 20 to 100 μm. [7] The Martens hardness calculated by the nanoindation method based on ISO 14577 under the following measurement conditions (1) and (2) is 100 N / mm². 2 ~300N / mm 2 The hard coat film according to [6], wherein the indentation recovery rate calculated by formula (1) below, obtained by determining the work of plastic deformation (Wplast) and the work of elastic deformation (Welast) from the load variation curve obtained by the nanoindation method, is greater than 75%. Measurement conditions (1) Measurement environment: temperature 23℃, humidity 50% Measurement conditions (2) Measurement program: A load is applied to the surface of the hard coat film using a Vickers indenter, gradually increasing the load at a rate of 1 mN / 5 seconds. After reaching 1 mN, the load is held for 2 seconds, and then the load is removed while decreasing it at a rate of 1 mN / 5 seconds. Formula (1): Indentation recovery rate (%) = [Welast / (Wplast + Welast)] × 100 [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an active energy ray curable composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate, a cured coating film using the same, and a hard coat film. [Modes for carrying out the invention]

[0011] The following describes in detail the active energy ray curable composition, cured coating film, and hard coat film of the present invention. However, the description of the constituent elements described below is merely an example (representative example) of one embodiment of the present invention and is not limited to these contents.

[0012] In the following explanation, "(meth)acryloyl" means acryloyl and / or methacryloyl. "(meth)acrylate" means acrylate and / or methacrylate. Furthermore, "(meth)acrylic" means acrylic and / or methacrylic.

[0013] (Active energy ray curable composition) The active energy ray curable composition of the present invention (hereinafter sometimes simply referred to as "the composition") contains the following components (A) to (C) as essential components. (A) Component: Inorganic fine particles (B) Component: A polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and a glass transition temperature (Tg) of the polymer when homopolymerized of 0°C or less. (C)Component: A polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains.

[0014] Generally, when a composition forming a cured coating film contains compounds with a low Tg and high mobility, such as polyethylene glycol chains or polytetramethylene glycol chains, the recovery rate of the cured coating film improves. On the other hand, as mentioned above, there is a trade-off relationship between the recovery rate and the elastic modulus. In order to improve the elastic modulus, if the crosslinking density is increased using polyfunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate or dipentaerythritol hexa(meth)acrylate, the elastic modulus improves, but the recovery rate decreases. The active energy ray curable composition of the present invention selectively contains component (B), which is a polyfunctional (meth)acrylate that contributes to improving the elastic modulus while having a low Tg and high mobility that contributes to improving the recovery rate, thus making it possible to achieve both a good recovery rate and an elastic modulus in the cured coating film.

[0015] Furthermore, the inventors have found that by including inorganic fine particles (component (A)), which are generally used to improve the elastic modulus, in the composition, it is possible to suppress the decrease in the recovery rate, which is in a trade-off relationship with the elastic modulus. The active energy ray curable composition of the present invention selectively contains component (A), which can contribute to improving the elastic modulus while suppressing the decrease in the recovery rate, thus enabling a balance between recovery rate and elastic modulus in the cured coating film.

[0016] Furthermore, the inventors have found that incorporating a polyfunctional (meth)acrylate (component (C)) having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains into the composition results in an excellent balance between recovery rate and elastic modulus. Since the active energy ray curable composition of the present invention selectively contains component (C), it is possible to achieve both recovery rate and elastic modulus in the cured coating film.

[0017] Therefore, the present invention can provide an active energy ray curable composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate, a cured coating film using the same, and a hard coat film.

[0018] The content of oxyethylene groups (-CH2-CH2-O-) in the solid content of the active energy ray curable composition is 14 to 30% by mass. By setting the oxyethylene group content to 14% by mass or more, it is possible to impart excellent indentation recovery rate to the cured coating film, improve the dispersibility of inorganic fine particles, and increase the hardness of the cured coating film. Furthermore, by setting the oxyethylene group content to 30% by mass or less, it is possible to suppress the decrease in the hardness of the cured coating film.

[0019] The oxyethylene group content mentioned above is expressed as the percentage (by mass) of oxyethylene groups relative to the total solid content (i.e., components that make up the active energy ray curable composition, excluding components that volatilize at room temperature or by heating as necessary, such as solvents) which is set at 100% by mass.

[0020] <(A) component> Component (A) is an inorganic fine particle. Examples of inorganic fine particles used in the composition of the present invention include zirconium oxide, silica, barium sulfate, zinc oxide, barium titanate, cerium oxide, alumina, titanium oxide, niobium oxide, zinc oxide, tin oxide, tungsten oxide, and antimony. Among these, silica and zirconium oxide are preferred, and silica is more preferred, as they tend to yield compositions that can form a cured coating film that achieves both excellent elastic modulus and recovery rate. Inorganic microparticles can be used individually or in combination of two or more types.

[0021] The shape of the inorganic fine particles is not particularly limited and may be spherical, hollow, solid, porous, rod-shaped, plate-shaped, fibrous, or irregularly shaped. Among these, the shape of the inorganic fine particles is preferably spherical from the viewpoint of transparency.

[0022] The inorganic fine particles used in the composition of the present invention may be in the form of a dispersion (sol) of inorganic fine particles. Examples of dispersion media for the dispersion include water or an organic solvent, but an organic solvent is preferred from the viewpoint of compatibility with other constituent components and dispersibility.

[0023] The organic solvent is not particularly limited, but examples include: aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and tetralin; aliphatic or alicyclic hydrocarbon solvents such as n-hexane, n-heptane, mineral spirits, and cyclohexane; halogenated solvents such as methyl chloride, methyl bromide, methyl iodide, methylenedichloride, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, and orthodichlorobenzene; ester or ester ether solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, and propylene glycol monomethyl ether acetate; diethyl ether, tetrahydrofuran, and 1,4-dioxane Examples include ether-based solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, and cyclohexanone; alcohol-based solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, 2-ethylhexyl alcohol, benzyl alcohol, and ethylene glycol; amide-based solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; sulfoxide-based solvents such as dimethyl sulfoxide; heterocyclic compound-based solvents such as N-methyl-2-pyrrolidone; and mixtures of two or more of these.

[0024] The dispersion of inorganic fine particles can be used in the dispersion medium at an inorganic fine particle concentration in the range of, for example, 1 to 50% by mass.

[0025] Examples of commercially available inorganic fine particles include "IPA-ST", "IPA-ST-L", "IPA-ST-ZL", "EG-ST", "PGM-ST", "DMAC-ST", "MEK-ST-40", "MEK-ST-L", "MEK-ST-ZL", "MIBK-ST", "MIBK-ST-L", "CHO-ST-M", "EAC-ST", "PMA-ST", and "TOL-ST" manufactured by Nissan Chemical Corporation.

[0026] The inorganic fine particles are preferably inorganic fine particles having (meth)acryloyl groups on their particle surface. By using inorganic fine particles having (meth)acryloyl groups on their particle surface, the elastic modulus of the cured coating film can be further improved. Examples of commercially available inorganic fine particles having (meth)acryloyl groups on their particle surface include "MEK-AC-2140Z", "MEK-AC-3140Y", "MEK-AC-4130Y", "MEK-AC-5140Z", "PGM-AC-2140Y", "PGM-AC-4130Y", "MIBK-AC-2140Z", and "MIBK-SD-L" from Nissan Chemical Corporation, "V-8802" and "V-8804" from JGC Catalysts & Chemicals Corporation, and "NANOBYK-3605", "BYK-UV3518", and "BYK-UV3519" from BYK-Chemie.

[0027] The primary particle diameter of inorganic fine particles is preferably in the range of 1 to 150 nm, and more preferably in the range of 1 to 100 nm, because compositions capable of forming cured coating films that achieve both excellent elastic modulus and recovery rate tend to be obtained. The primary particle diameter can be calculated, for example, from the relationship between the specific surface area (surface area per unit mass) S of the inorganic fine particles measured by the gas adsorption method (BET method), the density ρ of the inorganic fine particles, and the primary particle diameter D: D = 6 / (ρS). The primary particle diameter calculated from the above relationship is the average particle diameter, which is the diameter of the primary particle.

[0028] The content of component (A) in the solid content of the active energy ray curable composition is preferably in the range of 10 to 90% by mass, more preferably in the range of 20 to 85% by mass, and particularly preferably in the range of 30 to 80% by mass. When the content of component (A) is within the above range, a composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate tends to be obtained. The content of component (A) above is expressed as the percentage of the solid content of component (A) relative to the solid content of the composition (i.e., the components that constitute the active energy ray curable composition, excluding components that volatilize at room temperature or by heating as necessary, such as solvents), with the solid content of component (A) being set at 100% by mass.

[0029] <(B) component> Component (B) is a polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and the Tg of the polymer when homopolymerized is 0°C or lower. A polyfunctional (meth)acrylate is a compound that has at least two (meth)acryloyl groups in its molecule. (B) Component can be used alone or in combination of two or more types.

[0030] The number of carbon atoms in the alkylene chain of the alkylene glycol skeleton is preferably 2 to 10, more preferably 2 to 6, and particularly preferably 2 to 4, in order to obtain a composition that can form a cured coating film with excellent flexibility and sufficient elastic modulus. In other words, the alkylene glycol skeleton of component (B) is particularly preferably an ethylene glycol skeleton, a propylene glycol skeleton, or a butylene glycol skeleton.

[0031] The molecular weight of the alkylene glycol skeleton is 200 or more. A molecular weight of 200 or more allows for the formation of a cured coating film with excellent flexibility and sufficient elastic modulus. A molecular weight of 300 or more is preferable. On the other hand, there is no particular upper limit to the molecular weight of the alkylene glycol skeleton, but it is usually 5000 or less.

[0032] The number of repeating alkylene glycol skeletons is not particularly limited, as long as the molecular weight of the alkylene glycol skeleton is 200 or more. For example, the number of repeating alkylene glycol skeletons is between 2 and 100.

[0033] Component (B) has a glass transition temperature (Tg) of 0°C or lower when homopolymerized. If the polymer's Tg is 0°C or lower, a composition can be obtained that can form a cured coating film with excellent flexibility and sufficient elastic modulus. The polymer's Tg is preferably -10°C or lower, more preferably -20°C or lower. On the other hand, the lower limit of the polymer's Tg is not particularly limited, but is usually -80°C or higher.

[0034] The method for measuring the Tg of the above polymer is as follows. The Tg of the polymer is measured by putting the component (B) into a sealed pan and heating it in the range of -60°C to (thermal decomposition temperature (°C) - 5°C) at a heating rate of -10°C / min using a differential scanning calorimeter DSC (device name: DSC7000X, Hitachi High-Tech Corporation). As the Tg of the polymer, the value measured during the second heating cycle is used. When using a commercially available product as the component (B), if the Tg is described as a catalog value of the commercially available product, that value may be used as the Tg of the polymer when homopolymerized.

[0035] (B) component is not limited as long as it is a polyfunctional (meth)acrylate satisfying the above conditions, but is preferably a compound represented by the following formula (1) or formula (2).

Chemical formula

[0036]

Chemical formula

[0037] R 2 and R 5Alkylene groups with 1 to 10 carbon atoms in this context include methylene, ethylene, n-propylene, isopropylene, cyclopropylene, n-butylene, isobutylene, s-butylene, t-butylene, cyclobutylene, 1-methylcyclopropylene, 2-methylcyclopropylene, n-pentylene, 1-methyl-n-butylene, 2-methyl-n-butylene, 3-methyl-n-butylene, 1,1-dimethyl-n-propylene, 1,2-dimethyl-n-propylene, 2,2-dimethyl-n-propylene, and 1-ethyl-n- Propylene group, cyclopentylene group, 1-methylcyclobutylene group, 2-methylcyclobutylene group, 3-methylcyclobutylene group, 1,2-dimethylcyclopropylene group, 2,3-dimethylcyclopropylene group, 1-ethylcyclopropylene group, 2-ethylcyclopropylene group, n-hexylene group, 1-methyl-n-pentylene group, 2-methyl-n-pentylene group, 3-methyl-n-pentylene group, 4-methyl-n-pentylene group, 1,1-dimethyl-n-butylene group, 1,2-dimethyl-n-butylene group, 1,3-dimethyl-n-butylene Group, 2,2-dimethyl-n-butylene group, 2,3-dimethyl-n-butylene group, 3,3-dimethyl-n-butylene group, 1-ethyl-n-butylene group, 2-ethyl-n-butylene group, 1,1,2-trimethyl-n-propylene group, 1,2,2-trimethyl-n-propylene group, 1-ethyl-1-methyl-n-propylene group, 1-ethyl-2-methyl-n-propylene group, cyclohexylene group, 1-methyl-cyclopentylene group, 2-methyl-cyclopentylene group, 3-methyl-cyclopentylene group, 1-ethyl-cyclobutylene group, 2-ethyl-cyclobutylene n group, 3-ethyl-cyclobutylene group, 1,2-dimethyl-cyclobutylene group, 1,3-dimethyl-cyclobutylene group, 2,2-dimethyl-cyclobutylene group, 2,3-dimethyl-cyclobutylene group, 2,4-dimethyl-cyclobutylene group, 3,3-dimethyl-cyclobutylene group, 1-n-propyl-cyclopropylene group, 2-n-propyl-cyclopropylene group, 1-isopropyl-cyclopropylene group, 2-isopropyl-cyclopropylene group, 1,2,2-trimethyl-cyclopropylene group, 1,2,3-trimethyl-cyclopropylene group, 2,2,Examples include 3-trimethylcyclopropylene group, 1-ethyl-2-methylcyclopropylene group, 2-ethyl-1-methylcyclopropylene group, 2-ethyl-2-methylcyclopropylene group, 2-ethyl-3-methylcyclopropylene group, n-heptylene group, n-octylene group, n-nonylene group, or n-decanylene group. Among the above, R 2 and R 5 The group is preferably a methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, s-butylene group, or t-butylene group, with ethylene group being particularly preferred.

[0038] The degree of polymerization of the alkylene glycol skeleton, n in formulas (1) and (2), is preferably 2 to 100, and more preferably 5 to 50.

[0039] In equation (2), a is preferably 3 or 4, and more preferably 4. In equation (2), 4-a is an integer between 0 and 2. In equation (2), 4-a is preferably 0 or 1, and more preferably 0.

[0040] Examples of compounds corresponding to formula (1) include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate.

[0041] Examples of compounds corresponding to formula (2) include ethoxylated glycerin tri(meth)acrylate and ethoxylated pentaerythritol tetra(meth)acrylate.

[0042] Examples of compounds that do not fall under formulas (1) and (2) but are suitable as component (B) include ethoxylated bisphenol A (meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, (caprolactone-modified) isocyanurate (meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and ethoxylated dipentaerythritol poly(meth)acrylate. (B) Component may also be a derivative of the polyfunctional (meth)acrylate described above.

[0043] (B) Component can be a commercially available product. Examples of commercially available components for (B) include MIWON's "Miramer M280", "Miramer M282", "Miramer M284", "Miramer M286", "Miramer M2040", "Miramer M2070", "Miramer M2100", "Miramer M2200", "Miramer M2300", and "Miramer M3150", and Shin Nakamura Chemical Industry Co., Ltd.'s "NK Ester A-400", "NK Ester A-600", "NK Ester A-1000", "NK Ester APG-700", "NK Ester A-PTMG65", and "NK Ester ATM-35E".

[0044] The content of component (B) in the solid content of the active energy ray curable composition (solid content mass) is preferably in the range of 5 to 50% by mass, more preferably in the range of 10 to 40% by mass, and particularly preferably in the range of 15 to 35% by mass. If the content of component (B) is within the above range, a composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate can be obtained.

[0045] <(C) component> Component (C) is a polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains. (C) Component can be used alone or in combination of two or more types.

[0046] Component (C) is preferably a compound represented by the following formula (3) as a representative structure, or a compound having a branched structure in the polysiloxane skeleton formed by the condensation of the siloxane moieties of compounds represented by the following formula (3). [ka] (In formula (3), R 7Each of these independently represents a hydrogen atom, an alkyl group, or a phenyl group, and R 8 Each of these independently represents a hydrogen atom or a (meth)acryloyl group, and there are n R 8 At least two of them are (meth)acryloyl groups, Q 1 Each of these independently represents an alkylene group, an alkenylene group, or a phenylene group that may be substituted. n represents an integer greater than or equal to 2.

[0047] R 7Preferably, the alkyl group is an alkyl group having 1 to 10 carbon atoms. Specific examples of alkyl groups having 1 to 10 carbon atoms include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl-n- Propyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group , 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,Examples include 3-trimethylcyclopropyl group, 1-ethyl-2-methylcyclopropyl group, 2-ethyl-1-methylcyclopropyl group, 2-ethyl-2-methylcyclopropyl group, 2-ethyl-3-methylcyclopropyl group, and decyl group. Among these, the alkyl group is particularly preferably a methyl group or an ethyl group.

[0048] Q 1 The alkylene group is preferably an alkylene group having 1 to 10 carbon atoms. Specific examples of alkylene groups having 1 to 10 carbon atoms include those shown in formulas (1) and (2) above.

[0049] Q 1 The alkenylene group is preferably an alkenylene group having 2 to 10 carbon atoms. Examples of alkenylene groups having 2 to 10 carbon atoms include alkylene groups having 2 to 10 carbon atoms that have at least one double bond formed by removing hydrogen atoms from adjacent carbon atoms. Among alkenylene groups having 2 to 10 carbon atoms, vinylene groups are preferred.

[0050] Q 1 Examples of phenylene groups include 1,2-phenylene groups, 1,3-phenylene groups, and 1,4-phenylene groups.

[0051] "May be substituted" means that some or all of the hydrogen atoms present in the alkylene group, alkenylene group, or phenylene group may be substituted with, for example, a hydroxyl group, halogen atom, carboxyl group, nitro group, cyano group, methylenedioxy group, acetoxy group, methylthio group, amino group, alkyl group having 1 to 10 carbon atoms, or alkoxy group having 1 to 10 carbon atoms.

[0052] The above alkoxy groups having 1 to 10 carbon atoms include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, s-butoxy group, t-butoxy group, n-pentoxy group, 1-methyl-n-butoxy group, 2-methyl-n-butoxy group, 3-methyl-n-butoxy group, 1,1-dimethyl-n-propoxy group, 1,2-dimethyl-n-propoxy group, 2,2-dimethyl-n-propoxy group, 1-ethyl-n-propoxy group, n-hexyloxy group, 1-methyl-n-pentyloxy group, 2-methyl-n-pentyloxy group, 3-methyl-n-pentyloxy group, and 4-methyl-n - Examples include pentyloxy group, 1,1-dimethyl-n-butoxy group, 1,2-dimethyl-n-butoxy group, 1,3-dimethyl-n-butoxy group, 2,2-dimethyl-n-butoxy group, 2,3-dimethyl-n-butoxy group, 3,3-dimethyl-n-butoxy group, 1-ethyl-n-butoxy group, 2-ethyl-n-butoxy group, 1,1,2-trimethyl-n-propoxy group, 1,2,2-trimethyl-n-propoxy group, 1-ethyl-1-methyl-n-propoxy group, 1-ethyl-2-methyl-n-propoxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, and n-decanyloxy group.

[0053] In equation (3), n is preferably between 3 and 5000, and more preferably between 10 and 1000.

[0054] (C) Components can be used individually or in combination of two or more.

[0055] (C) component can be a commercially available product. Examples of commercially available (C) component include "KR-513" and "X-40-9296" from Shin-Etsu Chemical Co., Ltd., and "AC-SQ TA-100" and "MAC-SQ TM-100" from Toagosei Co., Ltd.

[0056] The content of component (C) in the solid content of the active energy ray curable composition (mass of solid content) is preferably in the range of 1 to 20% by mass, more preferably in the range of 1 to 17% by mass, and particularly preferably in the range of 2 to 15% by mass. If the content of component (C) is within the above range, a composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate can be obtained.

[0057] <(D) component> The active energy ray curable composition of the present invention preferably further contains component (D). Component (D) is a polyfunctional (meth)acrylate having a (meth)acryloyl group concentration of 7.0 mmol / g or more. (D) Component can be used alone or in combination of two or more types.

[0058] The (meth)acryloyl group concentration of component (D) is 7.0 mmol / g or higher, preferably 8.0 mmol / g or higher, and more preferably 9.0 mmol / g or higher. If the (meth)acryloyl group concentration is 7.0 mmol / g or higher, a composition capable of forming a hardened coating film with high hardness can be obtained. The (meth)acryloyl group concentration refers to the amount (mmol) of (meth)acryloyl groups per gram of component (D). Furthermore, the (meth)acryloyl group concentration is a value calculated theoretically from component (D).

[0059] Component (D) is not particularly limited as long as it is a polyfunctional (meth)acrylate other than components (B) and (C) above, and has a (meth)acryloyl group concentration of 7.0 mmol / g or more. Examples of component (D) include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, glycerin tri(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ethoxylated dipentaerythritol poly(meth)acrylate.

[0060] (D) Component can be a commercially available product. (D) Examples of commercially available products of component (D) include, for example, "Aronics® M-930", "Aronics® M-305", "Aronics® M-306", "Aronics® M-450", "Aronics® M-400", "Aronics® M-402", "Aronics® M-403", "Aronics® M-404", "Aronics® M-405", "Aronics® M-406", and "Aronics® M-471" from Toagosei Co., Ltd., "NK Ester A-TMM-3", "NK Ester A-TMMT", "NK Ester ATM-4E", "NK Ester A-DPH", and "NK Ester A-DPH-6E" from Shin Nakamura Chemical Industry Co., Ltd., and "Light Acrylate 1.9ND-A", "Light Acrylate PE-3A", and "Light Acrylate" from Kyoeisha Chemical Co., Ltd. Examples include "PE-4A", "Light Acrylate DPE-6A", and MIWON's "Miramer M200", "Miramer M300", "Miramer M340", "Miramer M500", and "Miramer M600".

[0061] When component (D) is included, the content of component (D) in the solid content of the active energy ray curable composition (mass of solid content) is preferably in the range of 0.5 to 10% by mass, more preferably in the range of 0.5 to 9% by mass, and particularly preferably in the range of 0.7 to 8% by mass. If the content of component (D) is within the above range, a composition capable of forming a cured coating film that achieves both excellent elastic modulus and recovery rate can be obtained.

[0062] <Photopolymerization initiator> The active energy ray curable composition of the present invention may further contain a photopolymerization initiator. The type of photopolymerization initiator is not particularly limited, and conventionally known photopolymerization initiators can be used.

[0063] Examples of photopolymerization initiators include various benzophenones such as benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4,4′-bisdimethylaminobenzophenone, 4,4′-bisdiethylaminobenzophenone, 4,4′-dichlorobenzophenone, Michlar's ketone, and 3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone;

[0064] Xanthones, thioxanthones, 2-methylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, and other xanthones and thioxanthones; various acyloin ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether;

[0065] α-diketones such as benzyl and diacetyl; sulfides such as tetramethylthiuram disulfide and p-tolyl disulfide; various benzoic acids such as 4-dimethylaminobenzoic acid and ethyl 4-dimethylaminobenzoate;

[0066] 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one,3,3′-carbonyl-bis(7-diethylamino)coumarin,1-hydroxycyclohexylphenyl ketone,2,2′-dimethoxy-1,2-diphenylethane-1-one,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one,2-H Droxy-2-methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2 -Methylpropan-1-one, 4-benzoyl-4′-methyldimethyl sulfide, 2,2′-diethoxyacetophenone, benzyldimethyl ketal, benzyl-β-methoxyethyl acetal, o-benzoylmethyl benzoate, bis(4-dimethylaminophenyl) ketone, p-dimethylaminoacetophenone, α,α-dichloro-4-phenoxyacetophenone, pentyl-4-dimethylaminobenzoate, 2-(o-chlorophenyl)-4,5-di Examples include phenylimidazolyl dimer, 2,4-bis-trichloromethyl-6-[di-(ethoxycarbonylmethyl)amino]phenyl-S-triazine, 2,4-bis-trichloromethyl-6-(4-ethoxy)phenyl-S-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-ethoxy)phenyl-S-triazine anthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, and β-chloranthraquinone. These photopolymerization initiators can be used alone or in combination of two or more.

[0067] Furthermore, among the above photopolymerization initiators, it is preferable to use one or more mixed systems selected from the group consisting of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, thioxanthone and thioxanthone derivatives, 2,2′-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, as these exhibit activity to a wider range of wavelengths of light and can improve the curability of the cured coating film of the above active energy ray curable composition.

[0068] Commercially available photopolymerization initiators include, for example, IGM's "Omnirad-1173", "Omnirad-184", "Omnirad-127", "Omnirad-2959", "Omnirad-369", "Omnirad-379", "Omnirad-907", "Omnirad-4265", "Omnirad-1000", "Omnirad-651", "Omnirad-TPO", "Omnirad-819", "Omnirad-2022", "Omnirad-2100", "Omnirad-754", "Omnirad-784", and "Omnirad Examples include "-500", "Omnirad-81", "KayaCure-DETX", "KayaCure-MBP", "KayaCure-DMBI", "KayaCure-EPA", and "KayaCure-OA" from Nippon Kayaku Co., Ltd., "VyCure-10" and "VyCure-55" from Stoufa Chemical, "Trigonal P1" from Akzo, "Sandoz-1000" from Sandoz, "Deep" and "Quantacure-PDO" from Apjohn, "Quantacure-ITX" and "Quantacure-EPD" from Wardbrenkinsop, and "Runtecure(registered trademark)-1104" from Runtec.

[0069] The amount of photopolymerization initiator is preferably such that it can fully exhibit its function as a photopolymerization initiator, and does not cause crystal precipitation or deterioration of the coating film properties. Specifically, it is preferably in the range of 0.05 to 20% by mass, and more preferably in the range of 0.1 to 10% by mass, relative to the total amount (solid content) of the active energy ray curable composition.

[0070] Furthermore, since the active energy ray curable composition can improve the curability of the cured coating film, it may also contain a photosensitizer.

[0071] Examples of photosensitizers include amine compounds such as aliphatic amines and aromatic amines, urea compounds such as o-tolylthiourea, and sulfur compounds such as sodium diethyldithiophosphate and s-benzylisothironium-p-toluenesulfonate.

[0072] <Other resin components with active energy ray curing properties> The active energy ray curable composition of the present invention may also be used in combination with other active energy ray curable resin components other than the above-mentioned components, as long as it does not impair the effects of the present invention. Preferably, the total content of components (A) to (D) is 50% by mass or more in the solid content of the active energy ray curable composition.

[0073] <Other optional additives> The active energy ray curable composition of the present invention may optionally contain various additives such as ultraviolet absorbers, polymerization inhibitors, antioxidants, organic solvents, inorganic fillers or polymer fine particles, pigments, defoamers, viscosity modifiers, leveling agents, flame retardants, and preservation stabilizers.

[0074] Examples of UV absorbers include triazine derivatives such as 2-[4-{(2-hydroxy-3-dodecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-{(2-hydroxy-3-tridecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2'-xanthen carboxy-5'-methylphenyl)benzotriazole, 2-(2'-o-nitrobenzyloxy-5'-methylphenyl)benzotriazole, 2-xanthen carboxy-4-dodecyloxybenzophenone, and 2-o-nitrobenzyloxy-4-dodecyloxybenzophenone. These UV absorbers can be used individually or in combination of two or more.

[0075] Examples of polymerization inhibitors include p-methoxyphenol, p-methoxycresol, 4-methoxy-1-naphthol, 4,4'-dialkoxy-2,2'-bi-1-naphthol, 3-(N-salicyloyl)amino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecanedihydrazide, styrene-phenol, N-isopropyl-N'-phenylbenzene-1,4-diamine, and 6-ethoxy-2,2,4-trimethyl-1 Phenolic compounds such as 2-dihydroquinoline, hydroquinone, methylhydroquinone, p-benzoquinone, methyl-p-benzoquinone, 2,5-diphenylbenzoquinone, 2-hydroxy-1,4-naphthoquinone, anthraquinone, diphenoquinone and other quinone compounds, melamine, p-phenylenediamine, 4-aminodiphenylamine, N,N'-diphenyl-p-phenylenediamine, Ni-propyl-N'-phenyl-p-phenylenediamine, N-(1.Amine compounds such as 3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, diphenylamine, 4,4'-dicumyl-diphenylamine, 4,4'-dioctyl-diphenylamine, poly(2,2,4-trimethyl-1,2-dihydroquinoline), styrene-diphenylamine, reaction products of styrene-diphenylamine and 2,4,4-trimethylpentene, reaction products of diphenylamine and 2,4,4-trimethylpentene, phenothiazine, distearylthiodipropionate, 2,2-bis({[3-(dodecyl Thioether compounds such as ruthio)propionyl]oxy}methyl)-1,3-propanediyl=bis[3-(dodecylthio)propionate], ditridecane-1-yl=3,3'-sulfandiyldipropanoate, N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, p-nitrosophenol, nitrosobenzene, p-nitrosodiphenylamine, α-nitroso-β-naphthol, N,N-dimethylp-nitrosoaniline, p-nitrosodiphenylamine, p-nitronedimethylamine, p-nitrone -N,N-diethylamine, N-nitrosoethanolamine, N-nitrosodi-n-butylamine, N-nitroso-Nn-butyl-4-butanolamine, N-nitroso-diisopropanolamine, N-nitroso-N-ethyl-4-butanolamine, 5-nitroso-8-hydroxyquinoline, N-nitrosomorpholine, N-nitroso-N-phenylhydroxylamine ammonium salt, nitrosobenzene, N-nitroso-N-methyl-p-toluenesulfonamide, N-nitroso-N-ethylurethane, N-nitroso-Nn Nitroso compounds such as propyl urethane, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 1-nitroso-2-naphthol-3,6-sulfonate sodium, 2-nitroso-1-naphthol-4-sulfonate sodium, 2-nitroso-5-methylaminophenol hydrochloride, 2-nitroso-5-methylaminophenol hydrochloride, esters of phosphoric acid and octadecane-1-ol, triphenyl phosphite, 3,9-dioctadecane-1-yl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5] Phosphate compounds such as undecane, trisnonylphenyl phosphite, (1-methylethylidene)-di-4,1-phenylenetetra-C12-15-alkyl ester, 2-ethylhexyl=diphenyl=phosphite, diphenylisodecyl phosphite, triisodecyl=phosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis(dimethyldithiocarbamato-κ(2)S,S')zinc, and diethyldithiocarbamate zinc Examples include zinc compounds such as zinc dibutyldithiocarbamate, nickel compounds such as bis(N,N-dibutylcarbamodithioato-S,S')nickel, and sulfur compounds such as 1,3-dihydro-2H-benzimidazole-2-thion, 4,6-bis(octylthiomethyl)-o-cresol, 2-methyl-4,6-bis[(octan-1-ylsulfanyl)methyl]phenol, dilaurylthiodipropionate, and 3,3'-distearyl thiodipropionate. These polymerization inhibitors can be used individually or in combination of two or more.

[0076] As antioxidants, compounds similar to those exemplified as polymerization inhibitors can be used, and antioxidants can be used alone or in combination of two or more.

[0077] Furthermore, commercially available polymerization inhibitors and antioxidants include, for example, "Q-1300" and "Q-1301" manufactured by Wako Pure Chemical Industries, Ltd., and "Sumiriser BBM-S" and "Sumiriser GA-80" manufactured by Sumitomo Chemical Co., Ltd.

[0078] Any organic solvent that dissolves components (A) to (D) can be used. For example, the organic solvents exemplified in the above-mentioned dispersion (sol) of inorganic fine particles can be used. These organic solvents can be used individually or in combination of two or more.

[0079] Examples of inorganic fillers include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. These inorganic fillers can be used individually or in combination of two or more types.

[0080] As pigments, commonly known and conventional inorganic pigments and organic pigments can be used.

[0081] Examples of inorganic pigments include white pigment, antimony red, red iron oxide, cadmium red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, carbon black, and graphite. These inorganic pigments can be used individually or in combination of two or more.

[0082] Examples of white pigments include titanium dioxide, zinc oxide, magnesium oxide, zirconium oxide, aluminum oxide, barium sulfate, silica, talc, mica, aluminum hydroxide, calcium silicate, aluminum silicate, hollow resin particles, and zinc sulfide. These white pigments can be used individually or in combination of two or more.

[0083] Examples of organic pigments include quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, ancenthron pigments, indanthron pigments, flavanthron pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, and azo pigments. These organic pigments can be used individually or in combination of two or more.

[0084] Examples of defoaming agents include silicone-based defoaming agents, polyether-based defoaming agents, and fatty acid ester-based defoaming agents. These defoaming agents can be used individually or in combination of two or more types.

[0085] Examples of viscosity modifiers include acrylic polymers and synthetic rubber latex that can be thickened by adjusting to an alkaline state, urethane resins that can be thickened by molecular association, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, polyvinyl alcohol, water-added castor oil, amide wax, oxidized polyethylene, metal soap, and dibenzylidene sorbitol. These viscosity modifiers can be used individually or in combination of two or more.

[0086] Examples of leveling agents include silicone compounds, acetylenediol compounds, and fluorine compounds. These leveling agents can be used individually or in combination of two or more.

[0087] Examples of flame retardants include ammonium phosphates such as red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, and polyammonium phosphate, as well as inorganic phosphorus compounds such as phosphate amides; phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phospholane compounds, organic nitrogen-containing phosphorus compounds, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,5-dihydrooxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide. Examples include cyclic organophosphorus compounds such as 10-(2,7-dihydrooxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and derivatives obtained by reacting them with compounds such as epoxy resins and phenolic resins; nitrogen-based flame retardants such as triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, and phenothiazines; silicone-based flame retardants such as silicone oil, silicone rubber, and silicone resins; and inorganic flame retardants such as metal hydroxides, metal oxides, metal carbonate compounds, metal powders, boron compounds, and low-melting-point glass. These flame retardants can be used individually or in combination of two or more types.

[0088] (Physical properties) The active energy ray curable composition of the present invention is preferably a hard coat film containing a cured coating film obtained by curing the composition, in which the Martens hardness, indentation modulus, and indentation recovery rate calculated by the nanoindentation method based on ISO 14577 under the following measurement conditions are within the ranges described below. Measurement conditions Equipment: Microhardness tester Fischerscope HM2000 (Manufactured by Fischer Instruments) Indenter: Vickers indenter (tetrahedral diamond cone) Test environment: Temperature 23°C, Humidity 50% Measurement program: A Vickers indenter is used to apply a load to the surface of a hard coat film, gradually increasing the load at a rate of 1 mN / 5 seconds. After reaching 1 mN, the load is held for 2 seconds, and then the load is removed while decreasing it at a rate of 1 mN / 5 seconds.

[0089] <Martens hardness> In this specification, Martens hardness is a value calculated by the nanoindentation method based on ISO 14577 under the above measurement conditions. The active energy ray curable composition of the present invention, in a hard coat film including a cured coating of the composition, has a Martens hardness of 100 N / mm². 2 ~300N / mm 2 Preferably, it is 120 N / mm 2 ~270N / mm 2 It is more preferable that the Martens hardness is within the above range. If the Martens hardness is within the above range, sufficient coating hardness can be ensured.

[0090] <Indentation modulus> The indentation modulus in this specification is a value calculated by the nanoindentation method based on ISO 14577 under the above measurement conditions. The active energy ray curable composition of the present invention preferably has an indentation modulus of 1.8 GPa to 4.0 MPa in a hard coat film including the cured coating film of the composition, and more preferably 2.1 GPa to 3.6 MPa. If the indentation modulus is within the above range, excellent flexibility and sufficient modulus can be ensured.

[0091] <Indentation recovery rate> In this specification, the indentation recovery rate is an index that indicates the extent to which a hard coat film recovers its total deformation due to its elasticity when deformed in the process of (i) applying stress for a certain period of time, (ii) holding the stress for a certain period of time, and (iii) releasing the stress at a constant rate, as described in the measurement program above. The closer the indentation recovery rate is to 100%, the easier it is to elastically deform and the easier it is to return to its original shape when scratches or dents occur, thus reducing the likelihood of cosmetic defects such as flex marks and cracks.

[0092] In this specification, the indentation recovery rate is the value of the elastic deformation power (%) calculated by the nanoindentation method based on ISO 14577 under the above measurement conditions, and this value is used directly as the indentation recovery rate (%). More specifically, the plastic deformation work (Wplast) and elastic deformation work (Welast) are determined from the load displacement curve obtained by the nanoindentation method based on ISO 14577 under the above measurement conditions, and the indentation recovery rate (%) is calculated using the following formula. Indentation recovery rate (%) = [Welast / (Wplast + Welast)] × 100

[0093] The active energy ray curable composition of the present invention preferably has an indentation recovery rate of over 75% in a hard coat film containing the cured coating of the composition, and more preferably over 77%. If the indentation recovery rate is over 75%, the occurrence of bending marks and cracks can be sufficiently suppressed, and a sufficient recovery rate can be ensured.

[0094] (Suitable uses) The active energy ray curable composition of the present invention can form a cured coating film that achieves both excellent elastic modulus and recovery rate, and is therefore particularly preferred for use in forming hard coat films for flexible displays. "For flexible displays" refers to any component of a flexible display, and examples include a film protecting the surface side of a display device (surface protection film), a substrate film for a touch sensor, and a film protecting the back side of a display device (back protection film). Examples of flexible displays include foldable displays, bendable displays that can be folded and bent, rollable displays that can be rolled up, and stretchable displays that can be expanded and contracted. The active energy ray curable composition of the invention is particularly preferred as a hard coat film for foldable displays. The foldable display may be bi-fold or tri-fold.

[0095] (cured coating) The cured coating film of the present invention is a cured reaction product obtained by curing the active energy ray curable composition of the present invention.

[0096] Methods for curing active energy ray-curable compositions include, for example, heating and irradiation with active energy rays such as ultraviolet light.

[0097] The material can be cured by heating it in a temperature range of 60-200°C for 0.5-60 minutes.

[0098] Furthermore, as a method of irradiating with active energy rays, for example, in the case of ultraviolet light, curing can be achieved by using ultraviolet lamps such as low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, gallium lamps, metal halide lamps, sunlight, and LEDs as ultraviolet light sources.

[0099] In addition to ultraviolet light as mentioned above, ionizing radiation such as electron beams, alpha rays, beta rays, and gamma rays can also be used as active energy rays.

[0100] The irradiation dose of the active energy rays is 0.05 to 5 J / cm². 2 It is preferable that the range be 0.1 to 3 J / cm². 2 It is more preferable that the range be 0.1 to 2 J / cm². 2 It is particularly preferable that the UV irradiation dose be within this range. The above UV irradiation dose is based on values ​​measured in the wavelength range of 300 to 390 nm using a UV checker UVR-N1 (manufactured by Japan Storage Battery Co., Ltd.).

[0101] The hardness of the cured coating is not particularly limited, and the pencil hardness measured in accordance with JIS K5600-5-4:1999 may be, for example, 3H or higher, or between 3H and 5H.

[0102] The thickness of the cured coating can be adjusted as appropriate depending on the application, but is generally preferably in the range of 0.01 to 100 μm. For flexible display applications, the thickness of the cured coating is preferably in the range of 20 to 100 μm.

[0103] (Hard coat film) The hard coat film of the present invention comprises a cured coating film and a substrate. More specifically, the hard coat film of the present invention has a layer (hard coat layer) consisting of the cured coating film of the present invention on a substrate.

[0104] One example of a method for producing the hard coat film of the present invention is to apply an active energy ray-curable composition to at least one surface of a substrate, and then irradiate it with active energy rays.

[0105] Examples of substrates include metal substrates, plastic substrates, glass substrates, paper substrates, wood substrates, and fibrous substrates. Among these, plastic substrates are preferred as substrates for hard coat films used for flexible displays.

[0106] The plastic substrate for flexible displays is not particularly limited as long as it has the flexibility to be repeatedly bent, and examples include plastic substrates made of polyester resins, polyimide resins, polyolefin resins, polycarbonate resins, acrylonitrile butadiene styrene copolymers (ABS), polystyrene resins, etc.

[0107] The thickness of the substrate is not particularly limited and may be, for example, 10 to 250 μm, 15 to 100 μm, or 20 to 80 μm.

[0108] Methods for applying the active energy ray-curable composition include, for example, application methods using a gravure coater, roll coater, comma coater, knife coater, air knife coater, curtain coater, kiss coater, shower coater, flow coater, spin coater, dipping, screen printing, spray, brush application, applicator, bar coater, etc.

[0109] The hard coat film of the present invention may have a functional film layer such as an anti-reflective film, a diffusion film, or a polarizing film, in addition to the substrate and the hard coat film layer.

[0110] The hard coat film of the present invention has a cured coating that achieves both excellent elastic modulus and recovery rate, and therefore, as described above, it is preferably used in flexible displays, and particularly preferably in foldable displays. [Examples]

[0111] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. Unless otherwise specified, "parts," "%," etc., in the examples refer to mass-based measurements.

[0112] [Raw materials] The raw materials used in the examples and comparative examples are as follows:

[0113] <(A) Component: Inorganic microparticles> <a1>Silica microparticles (Product name: MEK-AC-2140Z, manufactured by Nissan Chemical Corporation, particle size: 12nm) <a2>Silica microparticles (Product name: PGM-AC-3140Y, manufactured by Nissan Chemical Corporation, particle size: 22 nm) <a3>Silica microparticles (Product name: ELECOM V-8803, manufactured by JGC Catalysts & Chemicals Co., Ltd., irregularly shaped silica microparticles)

[0114] <(B) Component: A polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and a polymer Tg of 0°C or less when homopolymerized.> <b1>Ethoxylated pentaerythritol tetraacrylate (product name: NK Ester ATM-35E, manufactured by Shin Nakamura Chemical Industry Co., Ltd., Tg: -41℃) <b2>Polyethylene glycol 400 diacrylate (product name: Miramer M280, manufactured by MIWON, Tg: -25℃) <b3>Polyethylene glycol 600 diacrylate (product name: Miramer M286, manufactured by MIWON, Tg: -41℃) <b4>Polyethylene glycol 1000 diacrylate (product name: NK ester A-1000, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., Tg: -22℃)

[0115] <(C)Component: A polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains> <c1>Acrylic group-containing silicone oligomer (product name: KR-513, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0116] <(D) Component: Polyfunctional (meth)acrylate with a (meth)acryloyl group concentration of 7.0 mmol / g or higher> <d1>Pentaerythritol tritetraacrylate (product name: Arronix® M-450 (PETTA), manufactured by Toagosei Co., Ltd., (meth)acryloyl group concentration: 11.4 mmol / g) <d2>Dipentaerythritol penta and hexaacrylate (product name: Aronics® M-402 (DPHA), manufactured by Toagosei Co., Ltd., (meth)acryloyl group concentration: 10.4 mmol / g) <d3>Dipentaerythritol penta and hexaacrylate (product name: Aronics® M-405 (DPHA), manufactured by Toagosei Co., Ltd., (meth)acryloyl group concentration: 10.4 mmol / g) <d4>Ethoxylated dipentaerythritol polyacrylate (product name: NK Ester A-DPH-6E, manufactured by Shin Nakamura Chemical Industry Co., Ltd., (meth)acryloyl group concentration: 7.1 mmol / g) <d5>1,9-Nonanediol diacrylate (Product name: Light Acrylate 1.9ND-A, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acryloyl group concentration: 7.5 mmol / g)

[0117] <Photopolymerization initiator> <e1>1-Hydroxycyclohexylphenyl ketone (Trade name: Runtecure® 1104, manufactured by Runtec)

[0118] <Additives> <f1>1,2,2,6,6-Pentamethyl-4-piperidyl methacrylate (Product name: ADEKA Stab LA-82, manufactured by ADEKA Corporation) <f2>Polyether-modified polydimethylsiloxane (Trade name: BYK-333, manufactured by BIC Chemie Japan Co., Ltd.) <f3>Fluorine-based surfactant (product name: Megafac® F477, manufactured by DIC Corporation)

[0119] <Other resin components with active energy ray curing properties> <g1>A polyfunctional (meth)acrylic polymer having (meth)acryloyl and hydroxyl groups in its side chains (product name: SMP-250AP, manufactured by Kyoeisha Chemical Co., Ltd., (meth)acryloyl group concentration: 4.0 mmol / g)

[0120] <Base material> <s1>Polyester film (Product name: Cosmoshine A4160, manufactured by Toyobo Co., Ltd., thickness: 100 μm)

[0121] Tables 1 to 3 below show a list of the above raw materials. [Table 1]

[0122] [Table 2]

[0123] [Table 3]

[0124] The active energy ray curable composition was prepared as follows. (Example 1: Preparation of Active Energy Ray Curable Composition (1)) Silica microparticles (product name: MEK-AC-2140Z, manufactured by Nissan Chemical Corporation) 68.7 parts by mass (solid content), ethoxylated pentaerythritol tetraacrylate (product name: NK Ester ATM-35E, manufactured by Shin Nakamura Chemical Industry Co., Ltd.) 14.7 parts by mass, acrylic group-containing silicone oligomer (product name: KR-513, manufactured by Shin-Etsu Chemical Co., Ltd.) 5.2 parts by mass, dipentaerythritol penta and hexaacrylate (product name: Aronics® M-402 (DPHA), manufactured by Toagosei Co., Ltd.) 1.6 parts by mass, 1-hydroxycyclohexylphenyl ketone (product name: Runtecure 1104, manufactured by Runtec) 1.3 parts by mass, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (product name: Adekastab) 0.3 parts by mass of LA-82 (manufactured by ADEKA Corporation) and 0.1 parts by mass (by solid content) of polyether-modified polydimethylsiloxane (product name: BYK-333, manufactured by BYC Chemie Japan Co., Ltd.) were mixed, and the solid content was adjusted to 54% with methyl ethyl ketone to obtain an active energy ray curable composition (1). The content of oxyethylene groups in the solid content of the active energy ray curable composition (1) was 22% by mass.

[0125] (Examples 2-7: Production of active energy ray curable compositions (2)-(7)) Active energy ray curable compositions (2) to (7) were obtained using the same method as in Example 1 with the compositions and formulations shown in Table 4.

[0126] [Table 4]

[0127] (Comparative Examples 1-9: Preparation of Active Energy Ray Curable Compositions (8)-(16)) Active energy ray curable compositions (8) to (16) were obtained using the same method as in Example 1 with the compositions and formulations shown in Table 5.

[0128] [Table 5]

[0129] The hard coat film was prepared as follows: (Example 8: Preparation of hard coat film (R1)) The active energy ray-curable composition (1) obtained in Example 1 was applied to a 100 μm thick polyester film substrate (product name: Cosmoshine A4160, manufactured by Toyobo Co., Ltd.) using a bar coater and solvent-dried at 100°C for 90 seconds. Then, under a nitrogen atmosphere, ultraviolet light at 1000 mJ / cm² was applied using a high-pressure mercury lamp. 2 Irradiation was performed to obtain a hard coat film (R1) having a cured coating film with a thickness of 40 μm on a film substrate.

[0130] (Examples 9-14: Preparation of hard coat films (R2)-(R7)) Using the active energy ray curable compositions (2) to (7) obtained in Examples 2 to 7, hard coat films (R2) to (R7) were obtained in the same manner as the preparation of hard coat film (R1) in Example 1.

[0131] (Comparative Examples 7-15: Preparation of hard coat films (R8)-(R16)) Using the active energy ray curable compositions (8) to (16) obtained in Comparative Examples 1 to 6, hard coat films (R8) to (R16) were obtained in the same manner as the preparation of hard coat film (R1) in Example 1.

[0132] The hard coat films (R1) to (R16) obtained in the above examples and comparative examples were used for the following evaluations.

[0133] [Transparency] The hard coat films obtained in the examples and comparative examples were evaluated for their transparency by measuring the haze value using a haze meter (manufactured by Suga Test Instruments Co., Ltd., model number HZ-V3) in accordance with JIS K7136, as follows. A (Good): Haze value is 1.0% or less. B (Not practical): Haze value exceeds 1.0%.

[0134] [Martens hardness] The method for measuring Martens hardness using the nanoindentation method can be performed using a commercially available apparatus compliant with ISO 14577, following the indentation test procedure specified in ISO 14577, and calculating the resulting load-displacement curve. For the hard coat films obtained in the examples and comparative examples, the following measurement conditions were used to determine the Martens hardness (N / mm²) calculated based on the ISO 14577 standard. 2 ) was calculated. Measurement conditions Equipment: Microhardness tester Fischerscope HM2000 (Manufactured by Fischer Instruments) Indenter: Vickers indenter (tetrahedral diamond cone) Measurement environment: temperature 23℃, humidity 50% Measurement program: A Vickers indenter was used to apply a load to the surface of a hard coat film, gradually increasing the load at a rate of 1 mN / 5 seconds. After reaching 1 mN, the load was held for 2 seconds, and then the load was removed while decreasing the load at a rate of 1 mN / 5 seconds.

[0135] Calculated Martens hardness (N / mm 2 The following criteria were used to evaluate the products / services. A (Good): Martens hardness of 120-270 N / mm 2 B (Practical): Martens hardness of 100 N / mm 2 More than 120N / mm 2 Less than or 270 N / mm 2 Super 300N / mm 2 below C (Not practical): Martens hardness of 100 N / mm 2 Less than 300 N / mm 2 Super

[0136] [Indentation modulus] The indentation modulus (GPa), calculated according to the ISO 14577 standard, was used when the measurement was performed using the same method as for measuring Martens hardness. The calculated indentation modulus (GPa) was evaluated according to the following criteria. A (Good): Compression modulus is 2.1-3.6 GPa B (Practical): Compression modulus of elasticity is 1.8 or more but less than 2.1 GPa or greater than 3.6 GPa but less than or equal to 4.0 GPa. C (Not practical): Compression modulus less than 1.8 or greater than 4.0 GPa

[0137] [Indentation recovery rate] When measured using the same method as for measuring Martens hardness, the elastic deformation power (%) calculated according to the ISO 14577 standard was used directly as the indentation recovery rate (%). Specifically, the plastic deformation work (Wplast) and elastic deformation work (Welast) were determined from the load-displacement curve obtained in the above Martens hardness measurement, and the indentation recovery rate (%) was calculated using the following formula. Indentation recovery rate (%) = [Welast / (Wplast + Welast)] × 100 The calculated indentation recovery rate (%) was evaluated according to the following criteria. A (Good): Push-in recovery rate exceeds 77% B (Practical): Push-in recovery rate is between 75% and 77%. C (Not practical): Push-in recovery rate is 75% or less.

[0138] [Mandrel test] Using a mandrel testing machine (TP Giken Co., Ltd.'s "Bending Testing Machine"), the hard coat films obtained in the examples and comparative examples were wrapped around test rods, and the presence or absence of cracks was visually confirmed. The smallest diameter of the test rod without cracking was used as the evaluation result. A smaller value indicates superior flexibility. Test rods with diameters ranging from 2 mm to 10 mm in 1 mm increments were used.

[0139] Tables 6 and 7 show the evaluation results.

[0140] [Table 6]

[0141] [Table 7]

[0142] Examples 8 to 14 shown in Table 6 are examples of hard coat films using the active energy ray curable composition of the present invention. It was confirmed that the hard coat films exhibit excellent transparency and flexibility, as well as excellent elastic modulus and recovery rate.

[0143] On the other hand, Comparative Examples 7 and 8 are examples in which components (B) and (C) were not used as components of the active energy ray curable composition, but it was confirmed that the formed hard coat films had insufficient elastic modulus and recovery rate, as well as low flexibility. Comparative Example 9 is an example in which component (C) was not used as a component of the active energy ray curable composition, but it was confirmed that the formed hard coat film had insufficient recovery rate. Furthermore, Comparative Examples 10 to 12 are examples in which component (A) was not used as a component of the active energy ray curable composition, but it was confirmed that the formed hard coat films had insufficient elastic modulus. Furthermore, Comparative Examples 13 to 15 are examples in which components (A) to (D) were included as components of the active energy ray curable composition, but the content of oxyethylene groups in the solid content of the composition was not 14 to 30% by mass, but it was confirmed that Comparative Examples 13 and 14 had insufficient recovery rate and flexibility, and Comparative Example 15 had insufficient elastic modulus. [Industrial applicability]

[0144] The hard coat film using the active energy ray curable composition of the present invention is suitable for use in flexible displays because it has excellent transparency and flexibility, and achieves both excellent elastic modulus and recovery rate.

Claims

1. (A) Component: Inorganic fine particles (B) Component: A polyfunctional (meth)acrylate having an alkylene glycol skeleton with a molecular weight of 200 or more, and the glass transition temperature (Tg) of the polymer when homopolymerized is 0°C or lower. (C) Component: A polyfunctional (meth)acrylate having a polysiloxane skeleton in the main chain and (meth)acryloyl groups in the side chains. A curable composition containing active energy rays, The content of oxyethylene groups in the solid content of the active energy ray curable composition is 14 to 30% by mass. Active energy ray curable composition

2. The active energy ray curable composition according to claim 1, further comprising a polyfunctional (meth)acrylate having a (meth)acryloyl group concentration of 7.0 mmol / g or more, wherein the content of component (D) in the solid content of the active energy ray curable resin composition is 0.5 to 10% by mass.

3. The active energy ray curable composition according to claim 1, wherein the (C) component is a compound represented by the following formula (3), or a compound having a branched structure in the polysiloxane skeleton obtained by the condensation of siloxane moieties of compounds represented by the following formula (3). 【Chemistry 1】 (In formula (3), R ７ Each of these independently represents a hydrogen atom, an alkyl group, or a phenyl group, and R ８ Each of these independently represents a hydrogen atom or a (meth)acryloyl group, and n R ８ At least two of them are (meth)acryloyl groups, Q １ Each of these independently represents an alkylene group, an alkenylene group, or a phenylene group that may be substituted. n represents an integer of 2 or more.

4. The active energy ray curable composition according to claim 1 for forming a hard coat film for flexible displays.

5. A cured coating film which is a cured reaction product of an active energy ray curable composition according to any one of claims 1 to 4.

6. A hard coat film comprising a cured coating film and a substrate according to claim 5, wherein the thickness of the cured coating film is 20 to 100 μm.

7. The Martens hardness calculated by the nanoindation method based on ISO 14577 under the following measurement conditions (1) and (2) is 100 N / mm². ２ ~300 N / mm ２ The hard coat film according to claim 6, wherein the indentation recovery rate calculated by the following formula (1) is greater than 75% by determining the work of plastic deformation (Wplus) and the work of elastic deformation (Welast) from the load variation curve obtained by the nanoindation method. Measurement conditions (1) Measurement environment: temperature 23℃, humidity 50% Measurement conditions (2) Measurement program: A load is applied to the surface of the hard coat film using a Vickers indenter, gradually increasing the load at a rate of 1 mN / 5 seconds. After reaching 1 mN, the load is held for 2 seconds, and then the load is removed while decreasing it at a rate of 1 mN / 5 seconds. Formula (1): Indentation recovery rate (%) = [West / (Wplast + West)] × 100

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