Urethane resin, active energy ray curable resin composition, cured coating film, and laminate

Abstract

To provide a urethane resin which is used in a material having both excellent base material adhesion and coated film physical property (scratch resistance), and a high refractive index.SOLUTION: A urethane resin is a reaction product of hydroxyl group-containing (meth)acrylate (a1), and polyvalent isocyanate (a2). The urethane resin does not have a tricyclic or higher aromatic polycyclic structure. The hydroxyl group-containing (meth)acrylate (a1) has at least one aromatic ring structure in the molecule, and the aromatic ring structure is an aromatic monocyclic structure or an aromatic dicyclic structure.SELECTED DRAWING: None

Description

[[Technical Field]]

[0001] The present invention relates to a urethane resin, an active energy ray-curable resin composition, a cured coating film, and a laminate. [[Background Art]]

[0002] Cured coating films obtained from UV-curable resins are excellent in hardness, scratch resistance, and the like, and therefore are widely used as hard coat agents for protecting molded products, display surfaces, and various film materials from scratches. Furthermore, imparting optical properties such as antireflection functionality to hard coat layers by increasing the refractive index of the hard coat layer has also been extensively studied. In order to increase the refractive index of the above hard coat layer and enhance the antireflection function, a method of using a fluorene-based organic material is known (see Patent Document 1). Additionally, liquid crystal display devices are provided with brightness enhancement sheets such as prism sheets and microlens sheets for improving luminance. The higher the refractive index of a brightness enhancement sheet, the higher its brightness enhancement effect; therefore, development of resin materials having a molecular structure with a higher refractive index, and increasing the refractive index through addition of inorganic fine particles are being studied (see Patent Documents 2 and 3). [[Prior Art Literature]] [[Patent Documents]]

[0003] [[Patent Document 1]] International Publication No. WO 2020 / 145286 [[Patent Document 2]] Japanese Patent No. 6094720 [[Patent Document 3]] International Publication No. WO 2017 / 154589 [[Summary of the Invention]] [[Problems to be Solved by the Invention]]

[0004] However, the anti-reflective film described in Patent Document 1 exhibits a high refractive index due to having many aromatic compounds in its molecular framework, but its hardness and scratch resistance as a hard coat layer are not sufficient. The reactive dispersion described in Patent Document 2 has the characteristic of a high refractive index, but no example of a compound having urethane bonds in the organic matrix component is provided, and because pseudo-crosslinking derived from hydrogen bonds is not formed in the cured coating film, it has the problem of being inferior in physical strength such as coating film hardness and scratch resistance.

[0005] The present invention was made to solve the above problems, and aims to provide a urethane resin for use in materials that possesses excellent substrate adhesion and coating film properties (scratch resistance), as well as a high refractive index. [Means for solving the problem]

[0006] The contents of this disclosure include the following embodiments. [1] A urethane resin which is a reaction product of a hydroxyl group-containing (meth)acrylate (a1) and a polyvalent isocyanate (a2), The aforementioned urethane resin does not have a polycyclic aromatic structure with three or more rings. A urethane resin wherein the hydroxyl group-containing (meth)acrylate (a1) has at least one aromatic ring structure within the molecule, and the aromatic ring structure is either an aromatic monocyclic or aromatic bicyclic structure. [2] The urethane resin according to [1], wherein the polyvalent isocyanate (a2) has at least one aromatic ring structure in the molecule, and the aromatic ring structure is an aromatic monocyclic structure or an aromatic bicyclic structure. [3] The urethane resin according to [1] or [2], wherein the hydroxyl value of the hydroxyl group-containing (meth)acrylate (a1) is in the range of 100 to 300 mg KOH / g. [4] A urethane resin according to any one of [1] to [3], which is a reaction product of the hydroxyl group-containing (meth)acrylate (a1), the polyhydric isocyanate (a2), and a polyhydric alcohol (a3) ​​that does not have a (meth)acryloyl group in its molecule. [5] The urethane resin according to any one of [1] to [4], wherein the refractive index (594 nm) of the cured coating film formed after UV irradiation is 1.53 or higher. [6] A urethane resin according to any of [1] to [5], having a weight-average molecular weight in the range of 500 to 20,000. [7] An active energy ray curable resin composition containing the urethane resin described in any of [1] to [6] and inorganic nanoparticles. [8] [7] A cured coating film which is a cured product of the active energy ray curable resin composition described above. [9] The cured coating film described in [8], having a refractive index (594 nm) of 1.55 or higher.

[10] The cured coating film according to [8] or [9], wherein the haze value is 1.0% or less when the thickness of the cured coating film is 8 μm or more and 12 μm or less. A cured coating film as described in any of

[11] [8] to

[10] , Substrate and A laminate having the following properties. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a urethane resin for use in materials that possesses excellent substrate adhesion and coating film properties (scratch resistance), as well as a high refractive index. [Modes for carrying out the invention]

[0008] The present invention will be described in more detail below. However, the present invention is not limited to the embodiments shown below.

[0009] "~" means greater than or equal to the value before the "~" notation, and less than or equal to the value after the "~" notation. "(Meth)acrylic" is a general term for acrylic and methacrylic. "(Meth)acrylate compound" is a general term for acrylic resin and methacrylic resin. (Meth)acryloyl group is a general term for acryloyl group and methacryloyl group.

[0010] [Urethane resin] The urethane resin of one embodiment of the present invention (referred to as the urethane resin of this embodiment) is a reaction product of a hydroxyl group-containing (meth)acrylate (a1) and a polyvalent isocyanate (a2). The urethane resin of this embodiment does not have three or more aromatic polycyclic structures. The hydroxyl group-containing (meth)acrylate (a1) has at least one aromatic ring structure in its molecule, and the aromatic ring structure is either an aromatic monocyclic or aromatic bicyclic structure. Preferably, the polyvalent isocyanate (a2) has at least one aromatic ring structure in its molecule, and the aromatic ring structure is either an aromatic monocyclic or aromatic bicyclic structure.

[0011] Examples of aromatic monocyclic structures include benzene ring structures. Examples of aromatic dicyclic structures include naphthalene ring structures and biphenyl ring structures. Examples of aromatic polycyclic structures with three or more rings include fluorene ring structures, anthracene ring structures, phenanthrene ring structures, phenalene ring structures, tetracene ring structures, chrysene ring structures, triphenylene ring structures, pyrene ring structures, pentacene ring structures, and perylene ring structures.

[0012] The urethane resin according to this embodiment preferably has a coating film refractive index of 1.53 or higher for light with a wavelength of 594 nm, and more preferably 1.55 or higher. When the coating film refractive index for light with a wavelength of 594 nm is 1.53 or higher, a cured coating film with a high refractive index can be obtained when inorganic nanoparticles with a high refractive index are used. The weight-average molecular weight of the urethane resin according to this embodiment is preferably in the range of 500 to 20,000, more preferably in the range of 1,500 to 18,000, and even more preferably in the range of 2,000 to 15,000. When the weight-average molecular weight of the urethane resin according to this embodiment falls within the above range, the active energy ray curable resin composition can be adjusted to a viscosity suitable for coating, and a uniform and smooth coating film can be formed.

[0013] Examples of the urethane resin of the present embodiment include the following urethane resins (i) and (ii). From the viewpoint of obtaining a urethane resin that is less prone to side reactions and has excellent storage stability, the urethane resin of (i) or (ii) is preferred.

[0014] (i) A urethane resin obtained by reacting a hydroxyl group-containing (meth)acrylate (a1) with a polyvalent isocyanate (a2). (ii) A urethane resin obtained by reacting an isocyanate group-containing urethane prepolymer obtained by reacting a polyol with a polyvalent isocyanate (a2) under conditions of excess isocyanate groups, with a hydroxyl group-containing (meth)acrylate (a1). The polyol is preferably a polyhydric alcohol (a3) having no (meth)acryloyl group in the molecule.

[0015] <Hydroxyl group-containing (meth)acrylate (a1)> The hydroxyl group-containing (meth)acrylate (a1) according to the present embodiment is not particularly limited as long as it is a (meth)acrylate that has a hydroxyl group and at least one aromatic ring structure in the molecule, and the aromatic ring structure is an aromatic monocyclic structure or an aromatic bicyclic structure. It is preferable that the aromatic ring structure is a benzene ring structure. The method for synthesizing the hydroxyl group-containing (meth)acrylate (a1) according to the present embodiment is not particularly limited, and examples thereof include a reaction product of an epoxy compound having an aromatic ring structure and (meth)acrylic acid. Specific examples include 2-hydroxy-3-phenoxypropyl (meth)acrylate. One or two or more of these may be used. It is preferable that the hydroxyl group-containing (meth)acrylate (a1) according to the present embodiment is 2-hydroxy-3-phenoxypropyl (meth)acrylate. Specific examples of the hydroxyl group-containing (meth)acrylate (a1) include Aronix M-5700 (2-hydroxy-3-phenoxypropyl acrylate, hydroxyl value 252.5, manufactured by Toagosei Co., Ltd.).

[0016] <Polyvalent isocyanate (a2)> Examples of polyvalent isocyanates (a2) include aromatic isocyanate compounds and isocyanate compounds having an alicyclic structure. Aromatic isocyanate compounds are preferred. It is more preferable that the polyvalent isocyanate (a2) has at least one aromatic ring structure in its molecule, and that the aromatic ring structure is either an aromatic monocyclic or aromatic bicyclic structure.

[0017] Examples of aromatic isocyanate compounds include isocyanates such as toluene diisocyanate (TDI), xylene diisocyanate, nitrodiphenyl diisocyanate, diphenylpropane diisocyanate, dimethyldiphenylmethane diisocyanate, phenylene diisocyanate, naphthylene diisocyanate, dimethoxydiphenyl diisocyanate, nitrodiphenyl diisocyanate, diphenylpropane diisocyanate, dimethyldiphenylmethane diisocyanate, phenylene diisocyanate, naphthylene diisocyanate, dimethoxydiphenyl diisocyanate, hydrogenated TDI, hydrogenated xylene diisocyanate, hydrogenated MDI, and tetramethylxylene diisocyanate; and polymeric derivatives of these isocyanates, urethane-modified derivatives, urea-modified derivatives, allophanate-modified derivatives, biuret-modified derivatives, carbodiimide-modified derivatives, uretonimine-modified derivatives, uretdione-modified derivatives, and isocyanurate-modified derivatives. It may be one or more of these types.

[0018] Examples of isocyanate compounds having an alicyclic structure include isocyanates such as tetramethylene diisocyanate, HDI, methylpentane diisocyanate, lysine diisocyanate, and isophorone diisocyanate; polymeric forms of these isocyanates, urethane modified forms, urea modified forms, allophanate modified forms, biuret modified forms, carbodiimide modified forms, uretonimine modified forms, uretdione modified forms, and isocyanurate modified forms. One or more of these may be used.

[0019] Specific examples of polyvalent isocyanates (a2) include, for example, aromatic isocyanate compounds such as xylene diisocyanate and diphenylmethane diisocyanate; and isocyanate compounds having an alicyclic structure such as hydrogenated xylene diisocyanate and isophorone diisocyanate.

[0020] <Polyol> It is preferable that the polyol is a polyhydric alcohol (a3) ​​that does not have a (meth)acryloyl group in its molecule. Examples of polyhydric alcohols (a3) ​​that do not have a (meth)acryloyl group in their molecule include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentane glycol, neopentyl glycol, polytetramethylene glycol, hexanetriol, trimellillolpropane, ethylene oxide or propylene oxide adducts of bisphenol A, hydrogenated bisphenol A, and condensation polymers of the aforementioned polyhydric alcohols (a3) ​​that do not have a (meth)acryloyl group in their molecule with polybasic acids or polybasic acid anhydrides. It may be one or more of these. Examples of polybasic acids and polybasic anhydrides include aromatic polybasic acids such as phthalic acid and phthalic anhydride, and aliphatic polybasic acids such as adipic acid and sebacic acid.

[0021] <Method for synthesizing urethane resin> The urethane resin according to this embodiment can be obtained, for example, by any of the following methods (I) to (II). (I) A method for producing a urethane resin, comprising the step of reacting a hydroxyl group-containing (meth)acrylate (a1) with a polyvalent isocyanate (a2). (II) A method for producing a urethane resin, comprising the step of reacting an isocyanate group-containing urethane prepolymer, obtained by reacting a polyol and a polyvalent isocyanate (a2) under conditions of excess isocyanate groups, with a hydroxyl group-containing (meth)acrylate (a1). The polyol is preferably a polyhydric alcohol (a3) ​​that does not have a (meth)acryloyl group in its molecule.

[0022] The urethane resin according to this embodiment is preferably manufactured by method (I) or (II) from the viewpoint of being less prone to side reactions and having excellent storage stability. In method (I), in addition to the hydroxyl group-containing (meth)acrylate (a1), other polyols may be added as needed. The polyols described above can be used as the polyols. The polyol is preferably a polyhydric alcohol (a3) ​​that does not have a (meth)acryloyl group in its molecule. A specific example of the polyhydric alcohol (a3) ​​that does not have a (meth)acryloyl group in its molecule is, for example, Newpol BPE-20 (bisphenol A ethylene oxide (average number of moles ≈ 2) adduct) manufactured by Sanyo Chemical Industries, Ltd.

[0023] (Active energy ray curable resin composition) An active energy ray curable resin composition according to one embodiment of the present invention (sometimes referred to as the active energy ray curable resin composition of this embodiment) contains the urethane resin of this embodiment described above and inorganic nanoparticles. It may further contain a photopolymerization initiator.

[0024] [Inorganic nanoparticles] The average primary particle size of the inorganic nanoparticles in this embodiment is preferably 1 to 50 nm, and particularly preferably 1 to 30 nm, because it provides excellent dispersion stability and yields a cured product with high light transmittance and refractive index.

[0025] <Particle type> The inorganic nanoparticles in this embodiment are preferably silicon oxide or a group 4 metal oxide, and more preferably a group 4 metal oxide from the viewpoint of a high refractive index. The inorganic nanoparticles in this embodiment are preferably at least one selected from the group consisting of zirconium oxide, silicon oxide, and titanium oxide. From the viewpoint of a high refractive index, the inorganic nanoparticles in this embodiment are more preferably zirconium oxide. The inorganic nanoparticles in this embodiment are not particularly limited in terms of their crystal structure, but for example, if they are zirconium oxide, a monoclinic crystal structure is preferred because it provides excellent dispersion stability and yields a cured product with high light transmittance and refractive index.

[0026] <Particle shape> The inorganic nanoparticles used in this embodiment can be those that are generally known, and the particle shape is not particularly limited, but may be spherical, hollow, porous, rod-shaped, plate-shaped, fibrous, or amorphous. Among these, spherical is preferred because it provides excellent dispersion stability and yields a cured product with high light transmittance and refractive index.

[0027] <Zirconium oxide nanoparticles> The inorganic nanoparticles in this embodiment are preferably zirconium oxide nanoparticles. The zirconium oxide nanoparticles can be those that are generally known, and the particle shape is not particularly limited, but examples include spherical, hollow, porous, rod-shaped, fibrous, etc., and among these, spherical is preferred. Furthermore, the average primary particle size of the zirconium oxide nanoparticles according to this embodiment is preferably 1 to 50 nm, and more preferably 1 to 30 nm. In addition, the crystal structure is not particularly limited, but a monoclinic system is preferred. In this invention, the average primary particle diameter can be measured by directly measuring the size of the primary particles from electron microscope images using a TEM (transmission electron microscope). One such measurement method involves measuring the short-axis diameter and long-axis diameter of the primary particles of individual inorganic microparticles and taking their average as the average primary particle diameter. Specific examples of zirconium oxide nanoparticles according to this embodiment include UEP-100 (average primary particle diameter: 11 nm) manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd., and PCS (average primary particle diameter: 20 nm) manufactured by Nippon Denko Co., Ltd.

[0028] Furthermore, the amount of inorganic nanoparticles in 100% by mass of the total nonvolatile content of the active energy ray-curable resin composition of this embodiment is preferably in the range of 1 to 70% by mass, more preferably in the range of 5 to 50% by mass, and even more preferably in the range of 10 to 40%, from the standpoint that it is easy to handle when preparing the curable composition described later, the dispersion process time can be shortened, and the dispersion has excellent stability.

[0029] [Polyfunctional (meth)acrylate compounds] The active energy ray curable resin composition of this embodiment preferably contains, in addition to the urethane resin according to this embodiment, a polyfunctional (meth)acrylate compound that is not a urethane resin. The polyfunctional (meth)acrylate compound according to this embodiment has at least three (meth)acryloyl groups in its molecule.

[0030] Examples of the polyfunctional (meth)acrylate compounds according to this embodiment include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tris[(meth)acryloyloxyethyl]isocyanurate, glycerin tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, or ditrimethylolpropane hexa(meth)acrylate. These polyfunctional (meth)acrylate compounds can be used individually or in combination of two or more. Among these, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, reaction products of pentaerythritol and acrylic acid, and reaction products of dipentaerythritol and acrylic acid are preferred because they yield (meth)acrylic resins with excellent drying properties, ink flowability, and suitability for high-speed printing. Specific examples of the polyfunctional (meth)acrylate compounds according to this embodiment include, for example, "LumiCure DPA-600T" manufactured by Toagosei Co., Ltd., which is a mixture of dipentaerythritol hexaacrylate (DPHA) and dipentaerythritol pentaacrylate (DPPA).

[0031] [Other polymerizable unsaturated double bond groups] In addition to the urethane resin and polyfunctional (meth)acrylate compound according to this embodiment, the active energy ray curable resin composition of this embodiment can also use a compound having a polymerizable unsaturated double bond group that is neither the urethane resin nor the polyfunctional (meth)acrylate compound according to this embodiment. As the compounds having polymerizable unsaturated double bond groups, compounds having polymerizable unsaturated double bond groups such as (meth)acrylic compounds, fatty acid vinyl compounds, alkyl vinyl ether compounds, α-olefin compounds, vinyl compounds, and ethynyl compounds can be used.

[0032] Examples of (meth)acrylic compounds include aromatic (meth)acrylates, alkyl (meth)acrylates, alkylene glycol (meth)acrylates, compounds having a carboxyl group and a polymerizable unsaturated double bond, (meth)acrylic compounds having a hydroxyl group, nitrogen-containing (meth)acrylic compounds, and benzyl (meth)acrylate. Aromatic (meth)acrylates are preferred. Examples of aromatic (meth)acrylates include phenoxyethyl acrylate, bisphenol A ethylene oxide-modified diacrylate having fewer than three (meth)acryloyl groups in the molecule, and bisphenol A propylene oxide-modified diacrylate having fewer than three (meth)acryloyl groups in the molecule.

[0033] Specific examples of other polymerizable unsaturated double bond compounds according to this embodiment include, for example, "MIRAMER M140" (phenoxyethyl acrylate) and "MIRAMER M2200" (bisphenol A ethylene oxide modified diacrylate) manufactured by MIWON Corporation.

[0034] [Photopolymerization initiator] The photopolymerization initiator according to this embodiment is not particularly limited as long as it has the function of initiating the polymerization of (meth)acryloyl groups in the urethane resin according to this embodiment, and optionally contained polyfunctional (meth)acrylate compounds, etc., upon photoexcitation. Examples include intramolecular bond cleavage type photopolymerization initiators and intramolecular hydrogen abstraction type photopolymerization initiators. For example, monocarbonyl compounds, dicarbonyl compounds, acetophenone compounds, benzoin ether compounds, acylphosphine oxide compounds, aminocarbonyl compounds, etc., can be used.

[0035] Examples of intramolecular bond cleavage type photopolymerization initiators include acetophenone derivatives such as diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenylketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone; benzoin derivatives such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acylphosphine oxide derivatives such as 2,4,6-trimethylbenzoindiphenylphosphine oxide; and benzyl and methylphenylglyoxyesters.

[0036] Examples of intramolecular hydrogen abstraction type photopolymerization initiators include benzophenones such as benzophenone, o-benzoylmethyl-4-phenylbenzophenone, 4,4′-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, acrylic benzophenone, 3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone, and 3,3′-dimethyl-4-methoxybenzophenone; thioxanthones such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothiooxanthone; aminobenzophenones such as Mihila ketone and 4,4′-diethylaminobenzophenone; and 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, and camphorquinone.

[0037] Commercially available photopolymerization initiators include Omnirad-184, 651, 500, 907, 127, 369, 784, and 2959 from IGM-Resins, and Esacure ONE from TPO-H;DKSH Japan Co., Ltd. From the viewpoint of obtaining a cured coating film with excellent curability even with a small amount of additive, Omnirad-184 manufactured by IGM-Resins is preferred.

[0038] The photopolymerization initiator is not limited to the above-mentioned compounds; any substance capable of initiating polymerization by ultraviolet light is acceptable. These photopolymerization initiators may be used individually or in combination of two or more types. There are no particular restrictions on the amount of photopolymerization initiator used, but it is preferable to use an amount of 0.1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the total nonvolatile content of the active energy ray curable resin composition of this embodiment. Known organic amines and the like can also be added as sensitizers. Furthermore, in addition to the radical polymerization initiators mentioned above, cationic polymerization initiators can also be used in combination.

[0039] [Additives, etc.] The active energy ray curable resin composition of this embodiment may contain other additive components. Examples of additive components include silane coupling agents, dispersants, photosensitizers, curing accelerators, organic solvents, non-reactive resins, organic fillers, coupling agents, tackifiers, defoamers, leveling agents, adhesion aids, mold release agents, lubricants, UV absorbers, antioxidants, heat stabilizers, plasticizers, flame retardants, pigments, dyes, and other additive components.

[0040] <Silane coupling agent> Examples of the silane coupling agents include (meth)acryloyloxy-based silane coupling agents, acryloxy-based silane coupling agents, vinyl-based silane coupling agents, epoxy-based silane coupling agents, amino-based silane coupling agents, and ureido-based silane coupling agents.

[0041] Examples of the (meth)acryloyloxy-based silane coupling agents include 3-(meth)acryloyloxypropyltrimethylsilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, and 3-(meth)acryloyloxypropyltriethoxysilane.

[0042] Examples of the acryloxy-based silane coupling agents include 3-acryloxypropyltrimethoxysilane.

[0043] Examples of vinyl-based silane coupling agents include allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(2-methoxyethoxy)silane.

[0044] Examples of epoxy-based silane coupling agents include diethoxy(glycidyloxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. An example of a styrene-based silane coupling agent is p-styryltrimethoxysilane.

[0045] Examples of the amino-based silane coupling agents include N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-3-aminopropyltrimethoxysilane.

[0046] Examples of ureido-based silane coupling agents include 3-ureidopropyltriethoxysilane. Examples of chloropropyl-based silane coupling agents include 3-chloropropyltrimethoxysilane. Examples of mercapto-based silane coupling agents include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. Examples of sulfide-based silane coupling agents include bis(triethoxysilylpropyl)tetrasulfide. Examples of isocyanate-based silane coupling agents include 3-isocyanatetopropyltriethoxysilane. Examples of aluminum-based coupling agents include acetalkoxyaluminum diisopropylate.

[0047] These silane coupling agents may be used individually or in combination of two or more. Among them, those having a (meth)acryloyloxy group, a glycidyl group, or an epoxycyclohexyl group are preferred, and 3-(meth)acryloyloxypropyltrimethoxysilane is the most preferred. A specific example of a silane coupling agent is KBM-503 (3-(meth)acryloyloxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.

[0048] When the silane coupling agent is included, the content of the silane coupling agent is preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of inorganic nanoparticles contained in the active energy ray curable resin composition of this embodiment.

[0049] <Dispersant> Examples of the dispersant include polymers containing acidic groups such as carboxyl groups, sulfone groups, and phosphate groups. Among these, phosphate ester-based dispersants are preferred because they result in a curable composition with excellent stability and yield cured products with high light transmittance and refractive index.

[0050] A specific example of the dispersant used in this embodiment is, for example, DISPERBYK-111 (a phosphate ester-based dispersant) manufactured by Big Chemie.

[0051] In preparing the active energy ray curable resin composition of this embodiment, the content of the dispersant is not particularly limited, but it is preferable that the content of the dispersant be 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of the total mass of inorganic nanoparticles according to this embodiment.

[0052] [solvent] The active energy ray curable resin composition of this embodiment preferably contains a solvent. The solvent is not particularly limited, and various known organic solvents can be used. Specifically, examples include cyclohexanone, methyl isobutyl ketone, methyl ethyl ketone, acetone, acetylacetone, toluene, xylene, n-butanol, isobutanol, tert-butanol, n-propanol, isopropanol, ethanol, methanol, 3-methoxy-1-butanol, 3-methoxy-2-butanol, ethylene glycol monomethyl ether, ethylene glycol mono-n-butyl ether, 2-ethoxyethanol, 1-methoxy-2-propanol, diacetone alcohol, ethyl lactate, butyl lactate, propylene glycol monomethyl ether, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, 2-ethoxyethyl acetate, butyl acetate, isoamyl acetate, dimethyl adipate, dimethyl succinate, dimethyl glutarate, tetrahydrofuran, methylpyrrolidone, and the like. Among these, methyl ethyl ketone is preferred. These organic solvents can be used in combination of two or more types. The active energy ray-curable resin composition of this embodiment may, for example, include the solvent used in synthesizing each resin.

[0053] [Composition of an active energy ray-curable resin composition] The active energy ray curable resin composition of this embodiment yields a cured coating film that possesses both a high refractive index and excellent coating hardness. Therefore, the active energy ray curable resin composition of this embodiment contains, in 100% by mass of nonvolatile content, a total of 50 to 100% by mass of the inorganic nanoparticles, urethane resin, and optionally a polyfunctional (meth)acrylate compound, preferably 60 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 80 to 100% by mass. The method for evaluating the non-volatile content of the composition will be explained in the examples.

[0054] The active energy ray-curable resin composition of this embodiment is easy to handle when preparing the curable composition described later, allows for a reduction in the dispersion process time, and exhibits excellent dispersion stability. Therefore, it is preferable that the inorganic nanoparticles be present in 1 to 70% by mass, 5 to 50% by mass, and more preferably 10 to 40% by mass, per 100% by mass of the nonvolatile content of the active energy ray-curable resin composition.

[0055] The active energy ray-curable resin composition of this embodiment is easy to handle when preparing the curable composition described later, and the cured coating film is excellent in terms of curability. Therefore, it is preferable that the active energy ray-curable resin composition contains 1 to 50% by mass, and more preferably 10 to 40% by mass, of the urethane resin in 100% by mass of the nonvolatile content of the active energy ray-curable resin composition. The active energy ray-curable resin composition of this embodiment is easy to handle when preparing the curable composition described later, and it is also preferable to include 1 to 80% by mass, and more preferably 30 to 70% by mass, as it reduces the viscosity of the composition and improves coating workability.

[0056] The active energy ray curable resin composition of this embodiment, from the viewpoint of excellent UV curability when irradiated with UV, preferably contains 1 to 30% by mass, 2 to 20% by mass, and more preferably 1 to 10% by mass of a photopolymerization initiator per 100 parts by mass of the total of the inorganic nanoparticles, urethane resin, optionally a polyfunctional (meth)acrylate compound, and optionally other polymerizable unsaturated double bond group compounds.

[0057] [Method for preparing an active energy ray-curable resin composition] The method for producing the active energy ray curable resin composition of this embodiment is not particularly limited. For example, one method involves obtaining a dispersion of inorganic nanoparticles, and then mixing the dispersion of inorganic nanoparticles with the urethane resin, the photoinitiator, and optionally the polyfunctional (meth)acrylate compound, various other additives. The method for producing the active energy ray curable resin composition of this embodiment preferably includes the steps of: preparing an inorganic nanoparticle dispersion; and mixing the inorganic nanoparticle dispersion with a urethane resin, a photoinitiator, and optionally a polyfunctional (meth)acrylate compound and various other additives. The mixing method is not particularly limited, but one example is the use of a media-type wet disperser.

[0058] Furthermore, in the step of preparing the inorganic nanoparticle dispersion, at least a portion of the urethane resin, or, if necessary, at least a portion of the polyfunctional (meth)acrylate compound, may be added.

[0059] <Inorganic nanoparticle dispersion> The inorganic nanoparticle dispersion according to this embodiment preferably comprises, for example, the inorganic nanoparticles, the solvent, and the dispersant as an additive. The inorganic nanoparticle dispersion according to this embodiment may further comprise at least a portion of the urethane resin, or optionally at least a portion of the polyfunctional (meth)acrylate compound. The dispersant is preferably in the range of 50 to 300 mgKOH / g. In general, with dispersants, inorganic nanoparticles tend to aggregate within the system due to interactions between the inorganic nanoparticles and other resin components contained in the active energy ray curable resin composition of this embodiment, which can lead to a decrease in the storage stability of the active energy ray curable resin composition and a decrease in the transparency of the cured coating film. By using a dispersant with an acid value in the range of 50 to 300 mgKOH / g, a curable composition with excellent aging stability can be obtained, and the cured product will not only have a high refractive index but also excellent light transmittance and scratch resistance. The inorganic nanoparticle dispersion according to this embodiment more preferably further contains the silane coupling agent as an additive. Functional groups can be introduced to the surface of the inorganic nanoparticles using the various silane coupling agents described above.

[0060] The method for producing the inorganic nanoparticle dispersion according to this embodiment is not particularly limited, but examples include a method of dispersing raw materials containing the inorganic nanoparticles, the dispersant, and optionally the silane coupling agent in a media-type wet disperser.

[0061] The media-type wet disperser used in the above manufacturing method can be any commonly known type without limitation, such as a bead mill (e.g., Star Mill LMZ-015 manufactured by Ashizawa Finetech Co., Ltd., Ultra Apex Mill UAM-015 manufactured by Kotobuki Kogyo Co., Ltd.).

[0062] The media used in the disperser is not particularly limited as long as it is a commonly known bead, but preferred media include zirconium oxide, alumina, silica, glass, silicon carbide, and silicon nitride. The average particle size of the media is preferably 50 to 500 μm, and media with a particle size of 50 to 200 μm is more preferred. If the particle size is 50 μm or larger, the impact force on the raw material powder is appropriate, and dispersion does not require excessive time. On the other hand, if the particle size of the media is 500 μm or smaller, the impact force on the raw material powder is appropriate, which suppresses the increase in surface energy of the dispersed particles and prevents re-aggregation.

[0063] Furthermore, the dispersion process time can be shortened by using a two-stage method: first, using a large-particle media with high impact force in the initial stages of grinding the raw material powder, and then, once the particle size of the dispersed particles has decreased, using a small-particle media that is less prone to re-aggregation.

[0064] Furthermore, it is desirable to use a media that has been thoroughly polished in order to suppress the decrease in the light transmittance of the resulting dispersion.

[0065] In the manufacturing method using the media-type wet disperser, there are no particular restrictions on the order in which the raw materials are loaded into the disperser, but by supplying the dispersant last, a curable composition with excellent dispersion stability can be obtained using a small amount of dispersant. More specifically, one example is a method in which the raw materials other than the dispersant are loaded first, mixed or pre-dispersed, and then the dispersant is loaded last to perform the main dispersion process.

[0066] After dispersion is complete, the curable composition of the present invention can be obtained by adding various additives or removing volatile components by distillation, depending on the application.

[0067] Furthermore, the particle size (average particle size) of the inorganic nanoparticles in the inorganic nanoparticle dispersion is larger than the average primary particle size of the inorganic nanoparticles that are the raw materials of the inorganic nanoparticle dispersion, because some of the inorganic nanoparticles aggregate in the dispersion. Therefore, the average particle size of the inorganic nanoparticles in the inorganic nanoparticle dispersion is preferably 100 nm or less, and more preferably in the range of 20 to 100 nm, because this results in a cured product with a high refractive index and excellent light transmittance.

[0068] (cured coating) The cured coating film of this embodiment is a cured reaction product of the active energy ray curable resin composition of this embodiment described above. The cured coating film of this embodiment preferably has a refractive index (594 nm) of 1.500 or higher, and more preferably 1.55 or higher, from the viewpoint of enabling thin films when used in optical lenses, reducing the refractive index difference with transparent electrodes to make the transparent electrodes less noticeable in optical films, providing anti-reflective functionality when combined with a low refractive index layer, and improving the light extraction efficiency from the light-emitting part in LED encapsulants. In this embodiment, from the viewpoint of improving transparency, the cured coating film preferably has a haze value of 2.0% or less when the film thickness of the cured coating film is 8 μm or more and 1.0% or less.

[0069] [Method for manufacturing a hardened coating film] The method for manufacturing a cured coating film according to this embodiment includes, for example, a coating step of applying the active energy ray curable resin composition of this embodiment onto a substrate such as a transparent film and allowing it to dry naturally or by forced drying; and a curing step of irradiating the film of the active energy ray curable resin composition obtained in the coating step with active energy rays to cure it. As for the coating method on a substrate such as a transparent film, known methods can be used, such as methods using a rod or wire bar, or various coating methods such as microgravure, gravure, die, curtain, lip, slot, or spin.

[0070] The drying temperature and time are not particularly limited, but depending on the solvent used, they can be, for example, 50 to 150°C for 20 to 80 seconds.

[0071] The aforementioned active energy ray can be any active energy ray that causes the curable composition of the present invention to harden, but ultraviolet light is particularly preferred.

[0072] Sources of ultraviolet light include fluorescent chemical lamps, black lights, low-pressure, high-pressure, and ultra-high-pressure mercury lamps, metal halide lamps, and sunlight. For example, an 80W high-pressure mercury lamp can be used. The UV irradiation intensity can be kept constant throughout the curing process, or it can be varied during the curing process to fine-tune the physical properties after curing. For example, when using an 80W high-pressure mercury lamp under a nitrogen atmosphere, the UV irradiation intensity can be 0.5 to 3.0 kJ / m³. 2 It can be irradiated with this energy value.

[0073] In addition to ultraviolet light, other active energy rays such as visible light and electron beams can also be used.

[0074] (Laminated structure) A laminate according to one embodiment of the present invention includes a cured coating film and a substrate according to the above embodiment.

[0075] [Base material] Examples of substrates according to this embodiment include acrylic substrates mainly composed of polyethylene terephthalate (PET), triacetyl cellulose (TAC), cycloolefin polymer (COP), and polymethyl methacrylate (PMMA), as well as glass and silicon wafers. The film thickness of the substrate in this embodiment is preferably 1 to 300 μm, and more preferably 5 to 100 μm. Specific examples of the substrate according to this embodiment include, for example, a triacetylcellulose (TAC) substrate with a thickness of 40 to 80 μm.

[0076] [Method for manufacturing laminates] The method for manufacturing the laminate of this embodiment is not particularly limited and may include, for example, the steps of applying the active energy ray curable resin composition of this embodiment described above to the substrate and solvent-drying it, and irradiating it with active energy rays such as ultraviolet light to form a cured coating film. The manufacturing method for the laminate of this embodiment includes, for example, the steps of applying the activated energy ray-curable resin composition of this embodiment described above to a triacetylcellulose substrate film (TAC substrate film) with a thickness of 40 to 100 μm, and solvent-drying it at 60 to 100°C for 20 to 80 seconds, and shining ultraviolet light at a rate of 0.5 to 3.0 kJ / m² using a 60 to 100 W high-pressure mercury lamp under a nitrogen atmosphere. 2 Preferably, the step includes irradiating to form a cured coating film with a thickness of 5 to 20 μm on a TAC substrate film. [Examples]

[0077] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

[0078] <Method for measuring weight-average molecular weight> The weight-average molecular weight (Mw) is a value measured using gel permeation chromatography (GPC) under the following conditions. Measuring device: HLC-8420GPC manufactured by Tosoh Corporation column: Guard Column HXL-H, manufactured by Tosoh Corporation. TSKgel SuperHZM-M (manufactured by Tosoh Corporation) x 4 tubes Detector: RI (Differential Refractometer) Measurement conditions: Column temperature 40℃ Solvent: tetrahydrofuran Flow rate: 1.0ml / min Standard: Polystyrene Sample: 100 μl of a tetrahydrofuran solution containing 0.4% by weight (based on non-volatile content of the resin) filtered through a microfilter.

[0079] <Method for evaluating non-volatile content> 0.9–1.1 g of the sample was weighed into an aluminum container whose weight had been measured beforehand, and then diluted and mixed with 5 ml of toluene. After that, the aluminum container was placed in an explosion-proof dryer at 100°C for 1 hour, and the non-volatile content remaining in the aluminum container was calculated.

[0080] <Method for evaluating the average particle size of inorganic nanoparticles in an inorganic nanoparticle dispersion> The zirconium oxide dispersion (55% non-volatile content) obtained in Production Example 1 described below was diluted with methyl ethyl ketone to 0.5% non-volatile content. The average particle size was then measured using the particle size analyzer "ELSZ-1000" (manufactured by Otsuka Electronics Co., Ltd.) after adjusting the concentration to the optimal level using a light intensity monitor before measurement.

[0081] <Method for evaluating substrate adhesion (initial stage)> In the examples described below, cuts were made with a utility knife on the surface of the cured coating of the laminate to create 100 grid patterns of 1 mm x 1 mm. Cellophane adhesive tape was then applied over these grid patterns and rapidly peeled off. The number of grid patterns that remained without peeling was counted and evaluated according to the following criteria. ○: The number of remaining grid squares was 90 or more. ×: The number of remaining grid squares was less than 90.

[0082] <Method for evaluating substrate adhesion (after weather resistance test)> The laminates obtained in the examples described below were irradiated with light for 24 hours using an Atlas Corporation xenon weathering tester "Ci4000" (63°C, 50% humidity). Subsequently, the adhesion to the substrate (initial stage) was evaluated using the same method as described above, according to the following criteria. ○: The number of remaining grid squares was 90 or more. ×: The number of remaining grid squares was less than 90.

[0083] <Method for evaluating scratch resistance> Steel wool (Bonstar #0000, manufactured by Nippon Steel Wool Co., Ltd.) was placed on a 2 cm square indenter, and a load of 1 kg was applied to the indenter. An abrasion test was then performed by moving the coated surface of the laminate obtained in the examples and comparative examples described below back and forth 500 times. The haze value of the laminate before and after the abrasion test was measured using a "Haze Computer HZ-2" manufactured by Suga Test Instruments Co., Ltd., and the difference between these values ​​(dH) was used for evaluation according to the following criteria. Note that a smaller difference value (dH) indicates higher resistance to abrasion. A:dH was 1.0 or less. B:dH was between 1.0 and 3.0. The C:dH value was greater than 3.0.

[0084] <Method for evaluating the refractive index of a coating film in relation to light at a length of 594 nm> The refractive index of the coating film of the laminate obtained in the examples described below was measured at a temperature of 25°C and a wavelength of 594 nm using a refractive index measuring device, "Metricon Model 2010 / M Prism Coupler" (manufactured by Metricon Japan Co., Ltd.). ○: The refractive index of the coating film was 1.55 or higher. ×: The refractive index of the coating film was less than 1.55.

[0085] (Synthesis Example 1) "Method for synthesizing urethane acrylate (UA1)" In a flask equipped with a stirring rod, temperature sensor, and water-cooled condenser, 20.00 parts by mass of methyl ethyl ketone, 56.39 parts by mass of Aronics M-5700 (2-hydroxy-3-phenoxypropyl acrylate, hydroxyl value 252.5, manufactured by Toagosei Co., Ltd.), 0.02 parts by mass of methoquinone, and 0.02 parts by mass of dibutyltin dilaurate were charged and mixed with a stirring blade, and the temperature was raised to 60°C while blowing in dry air. 23.41 parts by mass of xylene diisocyanate were added dropwise, taking care to avoid exothermic reaction, to carry out the urethane formation reaction. After the dropwise addition was complete, the temperature was raised to 80°C and the reaction was continued. After confirming that the isocyanate weight% was 0.05% or less, the mixture was cooled to obtain urethane acrylate (UA1) with a resin solids content of 80%. The weight-average molecular weight of this urethane acrylate was 900.

[0086] (Synthesis Example 2) "Method for synthesizing urethane acrylate (UA2)" The procedure described in Synthesis Example 1 above was carried out in the same manner as described above, except that 20.00 parts by mass of methyl ethyl ketone, 10.86 parts by mass of Nieuport BPE-20 (bisphenol A ethylene oxide (average number of moles ≈ 2) adduct, manufactured by Sanyo Chemical Industries, Ltd.), 44.38 parts by mass of Aronics M-5700 (2-hydroxy-3-phenoxypropyl acrylate, hydroxyl value 252.5, manufactured by Toagosei Co., Ltd.), 0.02 parts by mass of methoquinone, 0.02 parts by mass of dibutyltin dilaurate, and 24.56 parts by mass of xylene diisocyanate were changed to obtain a urethane acrylate (UA2) with a resin solids content of 80%. The weight-average molecular weight of this urethane acrylate was 1500.

[0087] (Synthesis Example 3) "Method for synthesizing urethane acrylate (UA3)" The procedure described in Synthesis Example 1 above was carried out in the same manner as described above, except that the following were changed: 20.00 parts by mass of methyl ethyl ketone, 10.75 parts by mass of Nieuport BPE-20 (bisphenol A ethylene oxide (average number of moles ≈ 2) adduct, manufactured by Sanyo Chemical Industries, Ltd.), 43.95 parts by mass of Aronics M-5700 (2-hydroxy-3-phenoxypropyl acrylate, hydroxyl value 252.5, manufactured by Toagosei Co., Ltd.), 0.02 parts by mass of methoquinone, 0.02 parts by mass of dibutyltin dilaurate, and 25.10 parts by mass of 1,3-bis(isocyanatomethyl)cyclohexane. A urethane acrylate (UA3) with a resin solids content of 80% was obtained. The weight-average molecular weight of this urethane acrylate was 1500.

[0088] (Synthesis Example 4) "Method for synthesizing urethane acrylate (UA4)" The procedure described in Synthesis Example 1 was carried out in the same manner as above, except that the amounts were changed to 20.00 parts by mass of methyl ethyl ketone, 48.06 parts by mass of 4-hydroxybutyl acrylate, 0.02 parts by mass of methoquinone, 0.02 parts by mass of dibutyltin dilaurate, and 31.73 parts by mass of 1,3-bis(isocyanatomethyl)cyclohexane, to obtain a urethane acrylate (UA4) with a resin solids content of 80%. The weight-average molecular weight of this urethane acrylate was 700.

[0089] (Synthesis Example 5) "Method for synthesizing urethane acrylate (UA5)" The procedure described in Synthesis Example 1 above was carried out in the same manner as described above, except that the following were changed: 20.00 parts by mass of methyl ethyl ketone, 17.14 parts by mass of TBIS-G (9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, manufactured by Taoka Chemical Co., Ltd.), 33.81 parts by mass of 4-hydroxybutyl acrylate, 0.02 parts by mass of methoquinone, 0.02 parts by mass of dibutyltin dilaurate, and 28.84 parts by mass of xylene diisocyanate. A urethane acrylate (UA5) with a resin solids content of 80% was obtained. The weight-average molecular weight of this urethane acrylate was 2400.

[0090] [Table 1]

[0091] In Table 1, "M-5700" refers to "Arronix M-5700" (2-hydroxy-3-phenoxypropyl acrylate, hydroxyl value 252.5) ​​manufactured by Toagosei Co., Ltd. In Table 1, "4-HBA" refers to "4-HBA" (4-hydroxybutyl acrylate) manufactured by Osaka Organic Chemical Industry Co., Ltd. In Table 1, "XDI" refers to "Takenate 500" (xylene diisocyanate) manufactured by Mitsui Chemicals, Inc. In Table 1, "Hydrogenated XDI" refers to "Takenate 600" (1,3-bis(isocyanatomethyl)cyclohexane) manufactured by Mitsui Chemicals, Inc. In Table 1, "BPE-20" refers to "Newpol BPE-20" (bisphenol A ethylene oxide (average number of moles ≈ 2) adduct) manufactured by Sanyo Chemical Industries, Ltd. In Table 1, "TBIS-G" refers to "TBIS-G" (9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene) manufactured by Taoka Chemical Co., Ltd.

[0092] (Manufacturing Example 1) "Method for producing zirconium oxide dispersion as an inorganic nanoparticle dispersion" 50 parts by mass of UPE-100 (zirconium oxide nanoparticles, primary particle size 11 nm, manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd.), 7.5 parts by mass of KBM-503 (3-(meth)acryloyloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.), 10.0 parts by mass of DISPERBYK-111 (phosphate ester dispersant, manufactured by Big Chemie Co., Ltd.), and 55.3 parts by mass of methyl ethyl ketone were mixed and stirred in a dispersion stirrer for 30 minutes to achieve a rough dispersion. Next, the obtained mixture was dispersed using a media-type wet disperser (Star Mill LMZ-015, manufactured by Ashizawa Fine Tech Co., Ltd.) with zirconia beads with a particle size of 100 μm, and the non-volatile content was adjusted to 55% with methyl ethyl ketone to obtain a zirconium oxide dispersion with an average particle size of 46.2 nm. The non-volatile content here includes all compounds except methyl ethyl ketone.

[0093] (Example 1) "Adjustment of the laminate (L1)" By mixing 54.5 parts by mass of the zirconium oxide dispersion prepared as described above (55% non-volatile content), 25.0 parts by mass of urethane acrylate (UA1) (80% resin solids), 50.0 parts by mass of DPHA, and 3.0 parts by mass of the photopolymerization initiator Irg184, an active energy ray curable resin composition with 40% by weight of non-volatile content was obtained. Each of the obtained active energy ray curable resin compositions was applied to a triacetylcellulose (TAC) substrate (film thickness 60 μm) using a bar coater, and the solvent was dried at 80°C for 40 seconds. Next, under a nitrogen atmosphere, ultraviolet light was irradiated at 1.5 kJ / m2 with an 80 W high-pressure mercury lamp to obtain a laminate (L1) having a cured coating film with a film thickness of 10 μm on the TAC substrate film.

[0094] (Examples 2-6) "Preparation of laminates (L2) to (L6)" Laminates (L2) to (L6) were obtained using the same method as in Example 1 with the compositions and formulations shown in Table 2.

[0095] (Comparative Examples 1-2) "Preparation of laminates (L7) to (L8)" Laminates (L7) to (L8) were obtained using the same method as in Example 1 with the compositions and formulations shown in Table 2.

[0096] [Table 2]

[0097] Note that all values ​​listed in Table 2 for mass are non-volatile content values. In Table 2, "Inorganic Nanoparticle Dispersion" refers to the zirconium oxide dispersion obtained in Production Example 1. In Table 2, "MIRAMER M140" refers to "MIRAMER M140" (phenoxyethyl acrylate) manufactured by MIWON Co., Ltd. In Table 1, "MIRAMER M2200" refers to "MIRAMER M2200" (bisphenol A ethylene oxide modified diacrylate) manufactured by MIWON Co., Ltd. In Table 2, "Omn-184" refers to "Omnirad-184" manufactured by IGM Resins. In Table 2, "DPHA" refers to "LumiCure DPA-600T" (a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate) manufactured by Toagosei Co., Ltd.

[0098] (Consideration) This invention provides an active energy ray curable resin composition that combines excellent substrate adhesion and coating film properties (scratch resistance) with a high refractive index. This composition is suitable as a useful material in fields such as displays, semiconductors, and medical devices where high refractive index materials are required.

Claims

1. A hard coat layer forming composition containing a urethane resin which is a reaction product of a hydroxyl group-containing (meth)acrylate (a1), a polyhydric isocyanate (a2), and a polyhydric alcohol (a3) ​​that does not have a (meth)acryloyl group in its molecule, The aforementioned urethane resin does not have a polycyclic aromatic structure with three or more rings. The hydroxyl group-containing (meth)acrylate (a1) is 2-hydroxy-3-phenoxypropyl (meth)acrylate, The polyvalent isocyanate (a2) has at least one aromatic ring structure within its molecule, and the aromatic ring structure is an aromatic monocyclic structure. A hard coat layer forming composition wherein the polyhydric alcohol (a3) ​​that does not have a (meth)acryloyl group in the molecule is at least one selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentane glycol, neopentyl glycol, polytetramethylene glycol, hexanetriol, trimellillolpropane, ethylene oxide or propylene oxide adducts of bisphenol A, and hydrogenated bisphenol A.

2. The hard coat layer forming composition according to claim 1, wherein the hydroxyl value of the hydroxyl group-containing (meth)acrylate (a1) is in the range of 100 to 300 mg KOH / g.

3. The hard coat layer forming composition according to claim 1, wherein the refractive index (594 nm) of the cured coating film formed after UV irradiation is 1.53 or higher.

4. The hard coat layer forming composition according to claim 1, wherein the weight-average molecular weight of the urethane resin is in the range of 500 to 20,000.

5. The hard coat layer forming composition according to claim 1, further comprising inorganic nanoparticles.

6. A hard coat layer which is a cured product of the hard coat layer forming composition described in claim 1.

7. The hard coat layer according to claim 6, wherein the refractive index (594 nm) is 1.55 or greater.

8. The hard coat layer according to claim 6, wherein the haze value is 1.0% or less when the thickness of the cured coating film is 8 μm or more and 12 μm or less.

9. The hard coat layer according to claim 6, Substrate and A laminate having the following characteristics.

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