Active energy ray-curable composition, cured coating film, and film

Abstract

To provide an active energy ray-curable composition that can be applied to and cured on a substrate surface such as a COP film to obtain excellent adhesion to the substrate and hard coat properties without the need for pretreatment such as primer treatment or corona treatment or for a binder layer, and that can also suppress formation of interference fringes, as well as a cured coating film thereof and a film employing the same.SOLUTION: The active energy ray-curable composition of the present invention contains the following components (A) to (D) and has a refractive index of inorganic components calculated by the following formula (1) of 1.46 or more and less than 1.68. (A) component: photoinitiator; (B) component: inorganic fine particles having a refractive index of less than 1.53; (C) component: inorganic fine particles having a refractive index of 1.53 or more; (D) component: (meth)acrylate (d1) having a hydroxyl group and (meth)acrylate (d2) having no hydroxyl group. Formula (1): ((refractive index of (B) component×volume of (B) component)+(refractive index of (C) component×volume of (C) component)) / ((volume of (B) component)+(volume of (C) component)).SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Cyclic olefin resin (COP) films have excellent properties such as high transparency, low birefringence, low moisture absorption, and low moisture permeability, and are widely used in applications such as optical components, medical applications, packaging films, automobiles, and semiconductors. In particular, in optical applications, as displays such as those for televisions become larger, the use of COP films as an alternative to conventionally used plastic films such as polyethylene terephthalate (PET) and triacetyl cellulose (TAC) is being considered.

[0003] On the other hand, since COP films have insufficient surface hardness, they may be scratched during processing or use. Therefore, in order to improve abrasion resistance and scratch resistance, a protective layer such as a hard coat layer made of a cured coating film of an active energy ray-curable composition may be provided on the surface. However, since the main structure of a COP film is an alicyclic structure, the film surface has low polarity, poor surface wettability, and is not easily corroded by solvents. Therefore, when an active energy ray-curable composition for forming a hard coat layer is applied to the COP film, the coating material does not spread easily, resulting in poor adhesion (adhesion to the substrate) between the COP surface and the hard coat layer.

[0004] One method proposed for improving substrate adhesion is to hydrophilize the COP film surface by pretreatment such as primer treatment or corona treatment (see, for example, Patent Document 1). While this method can improve adhesion between the COP film surface and the hard coat layer, the application and drying of the primer layer increases the number of steps, resulting in problems such as reduced yield, increased costs, and environmental impact. Another method for ensuring substrate adhesion involves using large amounts of nanosilica particles (see, for example, Patent Documents 2 and 3). However, nanosilica has a lower refractive index than resins and COP films, and adding large amounts of it also reduces the refractive index of the hard coat formed, which creates the problem of prone to interference fringes. Such interference fringes can cause poor appearance in hard coat layers on displays and other devices. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-284158 [Patent Document 2] Japanese Patent Application Publication No. 2018-203887 [Patent Document 3] Japanese Patent Application Publication No. 2023-35866 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide an active energy ray-curable composition that can be applied to the surface of a substrate such as a COP film and cured to provide excellent adhesion to the substrate and hard coating properties, without the need for pretreatments such as primer treatment or corona treatment, or for a binder layer, and that can also suppress the occurrence of interference fringes; and to provide a cured coating film of the composition and a film using the composition. [Means for solving the problem]

[0007] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using two types of inorganic fine particles with different refractive indices, blending two types of (meth)acrylate, one with a hydroxyl group and one without a hydroxyl group, and further adjusting the refractive index (nD) after curing to a specific range, thereby completing the present invention.

[0008] That is, the present invention relates to the following inventions. [1] An active energy ray-curable composition containing the following components (A) to (D), wherein the refractive index of the inorganic component determined by the following formula (1) is 1.46 or more and less than 1.68: Component (A): Photoinitiator (B) Component: inorganic fine particles with a refractive index of less than 1.53 (C) Component: inorganic fine particles with a refractive index of 1.53 or higher Component (D): (meth)acrylate (d1) having a hydroxyl group and (meth)acrylate (d2) not having a hydroxyl group Equation (1): (Refractive index of component (B) × Volume of component (B) + Refractive index of component (C) × Volume of component (C)) / (Volume of component (B) + Volume of component (C)) [2] The active energy ray-curable composition according to [1], wherein component (B) contains silica fine particles having an average primary particle diameter in the range of 10 nm or more and 150 nm or less. [3] The active energy ray-curable composition according to [1], wherein component (C) contains zirconia or titania fine particles having an average primary particle diameter in the range of 10 nm or more and 100 nm or less. [4] The active energy ray-curable composition according to [1], wherein component (A) contains a hydrogen abstraction photoinitiator. [5] The active energy ray-curable composition according to [1], which contains, as component (E), any one dispersant selected from the group consisting of phosphate esters, carboxylate esters, sulfate esters, and sulfonate esters. [6] The active energy ray-curable composition according to [1], wherein the component (d1) contains a polyfunctional acrylate having a hydroxyl value of 80 mgKOH / g or more. [7] The active energy ray-curable composition according to [1], wherein the total content of the components (B) and (C) is 10 to 80 mass % relative to 100 mass % of the total solid matter in the composition. [8] A cured coating film of the active energy ray-curable composition according to any one of [1] to [7]. [9] The cured coating film according to [8], having a refractive index of 1.50 or more and 1.56 or less.

[10] A cyclic olefin resin film substrate, or a film having the cured coating film according to [8] on at least one surface of an olefin resin film substrate without primer treatment or corona treatment. [Effects of the Invention]

[0009] The active energy ray-curable composition of the present invention can be applied to the surface of a substrate such as a COP film and then cured to form a cured coating film that provides substrate adhesion and hard coat properties and can further suppress the occurrence of interference fringes, without requiring pretreatment such as primer treatment or corona treatment of the substrate or a binder layer. The hard coat layer, which is a cured coating film of the active energy ray-curable composition of the present invention, has high hardness and excellent scratch resistance, and can be used in a wide range of applications. Therefore, a film including the cured coating film of the present invention is suitable for applications such as a hard coat film for optical components such as displays. DETAILED DESCRIPTION OF THE INVENTION

[0010] The active energy ray-curable composition of the present invention (hereinafter, sometimes simply referred to as "the composition") contains the following components (A) to (D), and the refractive index of the inorganic component determined by the following formula (1) is 1.46 or more and less than 1.68: Component (A): Photoinitiator (B) Component: inorganic fine particles with a refractive index of less than 1.53 (C) Component: inorganic fine particles with a refractive index of 1.53 or higher Component (D): (meth)acrylate (d1) having a hydroxyl group and (meth)acrylate (d2) not having a hydroxyl group Equation (1): (Refractive index of component (B) × Volume of component (B) + Refractive index of component (C) × Volume of component (C)) / (Volume of component (B) + Volume of component (C)) In the present invention, the term "(meth)acrylate" refers to either or both of acrylate and methacrylate.

[0011] The refractive index of the inorganic component is preferably 1.48 or more and less than 1.66, and more preferably 1.50 or more and less than 1.64. When the refractive index of the inorganic component is in this range, a cured coating film that can suppress the occurrence of interference fringes can be formed. Volume of component (B) and component (C) [cm 3 ] is the mass [g] of the inorganic particles added in the composition and the density [g / cm 3 The density can also be calculated by dividing by the amount of component (B) and component (C), and the volume can be calculated from the blend amounts of component (B) and component (C). When component (B) is silica particles, the density is approximately 2.0 [g / cm 3 ], and when component (C) is zirconia particles, the density is approximately 6.0 [g / cm 3 ].

[0012] [Component (A): Photoinitiator] The photoinitiator is contained mainly to initiate the polymerization reaction of the composition containing component (D). When the composition is applied to a COP substrate, the photoinitiator is preferably a hydrogen abstraction photoinitiator, since this can further improve adhesion to the substrate. Component (A) can be used alone or in combination of two or more types.

[0013] The hydrogen abstraction photoinitiator here refers to a compound that undergoes a state change from a singlet excited state to a triplet excited state upon irradiation with active energy rays, and that can cause hydrogen abstraction from another compound in the same system to generate radical species, such as a ketone compound. In the present invention, component (A) enters an excited state upon irradiation with active energy rays, causing hydrogen abstraction from component (D), generating radical species derived from component (D). The radical species derived from component (D) abstract hydrogen from the cycloolefin skeleton or the like contained in the COP base material, thereby forming a covalent bond between component (D) and the base material. This is thought to result in improved adhesion between the cured coating film obtained by curing the composition and the base material.

[0014] Examples of hydrogen abstraction photoinitiators include benzophenone, o-benzoylmethylbenzoate-4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylated benzophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, and 4-methylbenzophenone. thioxanthone compounds such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone; xanthone compounds such as xanthone, 2-isopropylxanthone, 2,4-dimethylxanthone, 2,4-diethylxanthone, and 2,4-dichloroxanthone; and polymers having a benzophenone skeleton such as polybutylene glycol bis(4-benzoylphenoxy) acetate.

[0015] Of these, benzophenone compounds such as the polymers having a benzophenone skeleton are preferred as component (A) because they further improve the adhesion of the cured coating film.

[0016] Commercially available products of component (A) include, for example, 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, Omnirad-500, Omnirad-BP Flakes, and Omnirad-4MBZ. Flakes, Omnirad-OMBB, Omnirad-DETX, Omnirad-ITX, Omnirad-EMK, Omnirad-EDB, Omnirad-MBF, Omnipol-BP, Omnirad-1312, Omnirad-1314, Omnirad-1315, Omnirad-1316 (manufactured by IGM), Kayacure-DETX, Kayacure-MBP, Kayacure-DMBI, Kayacure-EPA, Kayacure-O A (manufactured by Nippon Kayaku Co., Ltd.), Vicure-10, Vicure-55 (manufactured by Stauffer Chemical Co., Ltd.), Trigonal P1 (manufactured by Akzo), Sandray 1000 (manufactured by Sandoz), Deep (manufactured by Upjohn), Quantacure-PDO, Quantacure-ITX, Quantacure-EPD (manufactured by Ward-Blenkinsop), Runtecure-1104, Runtecure-1108, Runtecure-1024 (manufactured by Runtec).

[0017] The content of component (A) is preferably 0.1 to 10 mass%, and more preferably 1 to 7 mass%, based on 100 mass% of all solids in the composition. Furthermore, the content is preferably 0.2 to 20 mass%, and more preferably 2 to 14 mass%, based on 100 parts by mass of a photocurable compound such as component (D). When the content of component (A) is within the above range, the amount of active energy rays absorbed by the surface of the composition when the composition is applied to a substrate and then irradiated with active energy rays can be reduced, resulting in improved adhesion between the cured coating film and the substrate.

[0018] [Component (B): inorganic fine particles with a refractive index of less than 1.53] Examples of inorganic fine particles with a refractive index of less than 1.53 include silica particles, magnesium fluoride particles, calcium fluoride particles, porous magnesium fluoride nanoparticles, and hollow calcium fluoride nanoparticles. Among these, silica particles are preferred because they can enhance adhesion to COP substrates when cured into a coating film. Examples of silica particles include hollow silica, powdered silica, colloidal silica, quartz, fumed silica, precipitated silica, silicic anhydride, fused silica, crystalline silica, and ultrafine amorphous silica. The shape of the silica particles is not particularly limited, and spherical, porous, rod-like, plate-like, fibrous, or amorphous silica particles can be used, with spherical particles being preferred. The refractive index (nD) of component (B) is preferably 1.00 to 1.50, more preferably 1.20 to 1.50. The refractive index (nD) can be measured using a refractometer using the minimum deviation method, critical angle method, or the like. Component (B) can be used alone or in combination.

[0019] Examples of powdered silica particles include Aerosil 50, Aerosil 200 (manufactured by Nippon Aerosil Co., Ltd.), SYLYSIA 250, SYLYSIA 250N, SYLYSIA 310P, SYLYSIA 320, SYLYSIA 350, SYLYSIA 370, SYLYSIA 380, SYLYSIA 420, SYLYSIA 430, SYLYSIA 440, SYLYSIA 450, SYLYSIA 470, SYLYSIA 530, SYLYSIA 550, SYLYSIA 710, SYLYSIA 730, SYLYSIA 740, SYLYSIA 770, SYLYSIA 300S, SYLYSIA 660, SYLYSIA 852, SYLYSIA 882, SYLYSIA 328, SYLYSIA 358, SYLYSIA 448, SYLYSIA 446MU, SYLOSPHERE C-0809, SYLOSPHERE C-1504, and SYLOSPHERE C-1510 (manufactured by Fuji Silysia Chemical Ltd.). Commercially available colloidal silica includes, for example, methanol silica sol, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, and ST-OL (manufactured by Nissan Chemical Industries, Ltd.).

[0020] Surface-modified silica particles may also be used, such as the above-mentioned silica particles that have been surface-treated with a reactive silane coupling agent having a hydrophobic group or modified with a compound having a (meth)acryloyl group. Examples of commercially available powdered silica modified with a compound having a (meth)acryloyl group include Aerosil RM50, Aerosil R7200, and Aerosil R711 (manufactured by Nippon Aerosil Co., Ltd.). Examples of commercially available colloidal silica modified with a compound having a (meth)acryloyl group include MIBK-SD, MEK-SD, MA-ST-M, MA-ST-L, IPA-ST, IPA-ST-L, IPA-ST-ZL, IPA-ST-UP, EG-ST-XL-30, MEK-ST-40, MEK-ST-L, MEK-ST-ZL, MEK-ST-UP, MEK-AC-2140Z, MEK-AC-4130Y, MEK-AC-5140Z, MEK-AC-5340Z, PGM-ST, NBA-ST, XBA-ST, and DMAC-ST (manufactured by Nissan Chemical Industries, Ltd.).

[0021] The average primary particle diameter of component (B) is preferably 10 nm or more and 150 nm or less, more preferably 10 nm or more and 120 nm or less, and particularly preferably 10 nm or more and 100 nm or less. When the average primary particle diameter is within the above range, the cured coating film can have high adhesion to COP substrates. The average primary particle diameter can be measured by directly measuring the size of primary particles from electron micrographs using a TEM (transmission electron microscope). For example, one method for measuring the minor axis diameter and major axis diameter of each primary particle of inorganic fine particles and averaging them to determine the average primary particle diameter of the primary particles can be used.

[0022] The content of component (B) is preferably 2 to 40 mass%, more preferably 5 to 30 mass%, and particularly preferably 10 to 25 mass%, based on 100 mass% of the total solids in the composition. Furthermore, the content is preferably 10 to 80 mass%, more preferably 20 to 70 mass%, and particularly preferably 30 to 60 mass%, based on 100 mass% of the total (solids) of components (B) and (C). A content within the above range ensures high adhesion to COP substrates when formed into a cured coating film.

[0023] [Component (C): inorganic fine particles with a refractive index of 1.53 or higher] As inorganic fine particles having a refractive index of 1.53 or more, zirconia fine particles and titania fine particles are preferred because of their high refractive index. The refractive index of component (C) is preferably 1.60 to 2.3, more preferably 1.80 to 2.2. The refractive index (nD) can be measured using a refractometer by the minimum deviation method, critical angle method, or the like. Component (C) can be used alone or in combination of two or more types.

[0024] The use of the aforementioned component (B) in combination with inorganic fine particles having a refractive index of 1.53 or higher can suppress the occurrence of interference fringes in a cured coating film. Interference fringes occur when light reflected at the air layer / hard coat layer interface and light reflected at the hard coat layer / substrate interface interfere with each other due to differences in refractive index between the layers in the laminate, enhancing or reducing the reflected light of specific wavelengths. Therefore, it is believed that the occurrence of interference fringes can be suppressed by suppressing the reflection of light reflected at the hard coat layer / substrate interface. Thus, an effective way to suppress light reflection is to match the refractive index of the hard coat layer to that of the substrate. Therefore, it is important to increase the refractive index of the hard coat layer, and the composition contains component (C), which has a refractive index of 1.53 or higher.

[0025] As the zirconia microparticles, commonly known ones can be used, and the particle shape is not particularly limited, but examples include spherical, hollow, porous, rod-like, and fibrous shapes, with spherical being preferred. Examples of commercially available zirconia microparticles that can be used include Zirconeo-Cp, Zirconeo-Rp (manufactured by ITEC Co., Ltd.), UEP-100 (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), and PCS (manufactured by Nippon Denko Co., Ltd.). Examples of commercially available zirconia microparticle dispersions that can be used include Zircostar ZP-153 and Zircostar HR-101 (manufactured by Nippon Shokubai Co., Ltd.).

[0026] Known titania particles can be used. The particle shape is not particularly limited, but examples include spherical, hollow, porous, rod-like, and fibrous shapes. Among these, spherical shapes are preferred. Furthermore, titania particles obtained by either a calcination method or a wet method can be used. Examples of commercially available titania particles include TTO-51, 55 series, TTO-S, and TTO-V series (manufactured by Ishihara Sangyo Kaisha), and SR-0820, SR-0821, SR-0823, and SR-0827 (manufactured by Daihachi Chemical Industry Co., Ltd.).

[0027] The average primary particle diameter of component (C) is preferably 10 nm or more and 100 nm or less, more preferably 10 nm or more and 80 nm or less, and particularly preferably 10 nm or more and 50 nm or less. When the average primary particle diameter is within the above range, the cured coating film can have high adhesion to COP substrates. The average primary particle diameter can be measured by directly measuring the size of primary particles from electron micrographs using a TEM (transmission electron microscope). For example, one method for measuring the minor axis diameter and major axis diameter of each primary particle of inorganic fine particles and averaging them to determine the average primary particle diameter of the primary particles can be used.

[0028] The content of component (C) is preferably 2 to 50 mass%, more preferably 5 to 40 mass%, and particularly preferably 10 to 30 mass%, based on a total of 100 mass% of all solids in the composition. The combined content of components (B) and (C) is preferably 10 to 80 mass%, more preferably 20 to 70 mass%, and particularly preferably 35 to 60 mass%, based on a total of 100 mass% of all solids in the composition. When the content is within the above range, the refractive index of the cured coating film can be sufficiently increased, and the occurrence of interference fringes can be suppressed.

[0029] [Component (D): (meth)acrylate (d1) having a hydroxyl group and (meth)acrylate (d2) not having a hydroxyl group] Component (D) is a photocurable compound for forming a cured coating film, and in the composition, a (meth)acrylate (d1) having a hydroxyl group and a (meth)acrylate (d2) not having a hydroxyl group are used in combination to maintain the dispersibility of inorganic fine particles such as component (C) and the substrate adhesion of the cured coating film. The number of hydroxyl groups in the (meth)acrylate (d1) having a hydroxyl group is not particularly limited, but is 1 or more, preferably 2 or more.

[0030] The hydroxyl group-containing (meth)acrylate component (d1) preferably has a hydroxyl value of 80 mgKOH / g or more, more preferably 100 mgKOH / g or more. A hydroxyl value of 80 mgKOH / g or more improves the dispersibility of inorganic particles, preventing poor appearance due to particle aggregation when forming a coating film. The hydroxyl value can be measured by neutralization titration or the like in accordance with JIS K 0070-1992.

[0031] The (meth)acrylate (d1) having a hydroxyl group may be, for example, any of mono(meth)acrylate, di(meth)acrylate, tri(meth)acrylate, tetra(meth)acrylate, penta(meth)acrylate, and hexa(meth)acrylate, but polyfunctional acrylates having many (meth)acrylate groups are preferred in that they can increase the hardness of the cured coating film, and it is preferable to use tri(meth)acrylate, tetra(meth)acrylate, penta(meth)acrylate, hexa(meth)acrylate, and acrylic(meth)acrylate. The (meth)acrylate (d1) having a hydroxyl group can be used alone or in combination of two or more.

[0032] Examples of hydroxyl group-containing mono(meth)acrylates include 1-hydroxymethyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, hydroxycyclohexyl(meth)acrylate, 4-(hydroxymethyl)cyclohexylmethyl(meth)acrylate, 4-(hydroxymethyl)cyclohexylmethyl 2-hydroxypropionate, hydroxyphenyl(meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, and 2-hydroxy-3-methacrylpropyl acrylate.

[0033] Examples of hydroxyl group-containing di(meth)acrylates include 2-hydroxy-3-acryloyloxypropyl(meth)acrylate, pentaerythritol di(meth)acrylate, 2-hydroxy-1,3-di(meth)acrylate, 2-hydroxy-3-acryloyloxypropyl(meth)acrylate, 2-hydroxy-1,3-di(meth)acryloxypropane, and glycerin di(meth)acrylate.

[0034] An example of a hydroxyl group-containing tri(meth)acrylate is pentaerythritol tri(meth)acrylate. An example of a hydroxyl group-containing tetra(meth)acrylate is dipentaerythritol tetra(meth)acrylate. An example of a hydroxyl group-containing penta(meth)acrylate is dipentaerythritol penta(meth)acrylate.

[0035] Commercially available products of the (meth)acrylate (d1) having a hydroxyl group include, for example, HEA, HPA, 4-HBA, Viscoat #300 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Miramer M340, Miramer M500 (manufactured by MIWON Co., Ltd.), Light Ester HO-250(N), Light Ester HOP(N), Light Ester HOA(N), Light Ester HOP-A(N), Light Ester HOB(N), Light Ester G-101P, Light Ester G-201P, Light Acrylate HOB-A (manufactured by Kyoeisha Chemical Co., Ltd.), NK Ester 702A, NK Ester 701A (manufactured by Shin-Nakamura Chemical Co., Ltd.), Aronix M-215, Aronix M-305, Aronix M-306, Aronix M-450, Aronix M-400, Aronix M-402, Aronix M-404, Aronix M-406, Aronix M-471, Aronix M-405, Aronix M-920, Aronix M-930 (manufactured by Toagosei), Luxidia EMS-635, Luxidia V-6840, Luxidia V-6850, Luxidia V-6841, Luxidia ELS-818, Luxidia EVS-301 (manufactured by DIC) can be used.

[0036] The content of the hydroxyl group-containing (meth)acrylate (d1) is preferably 10 to 70 mass%, more preferably 20 to 65 mass%, and particularly preferably 30 to 60 mass%, based on 100 mass% of the total solid matter of the (D) component. Furthermore, the content is preferably 5 to 60 mass%, more preferably 10 to 50 mass%, and particularly preferably 15 to 40 mass%, based on 100 mass% of the total solid matter of the composition. A content within the above range improves the dispersibility of the inorganic particles, resulting in a coating film with a good appearance.

[0037] Examples of the (meth)acrylate (d2) having no hydroxyl group include n-butyl (meth)acrylate, ter-butyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, butoxydiethylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, and phenoxyethyl (meth)acrylate. , isobornyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, stearyl (meth)acrylate, ethoxy-diethylene glycol (meth)acrylate, 2-ethylhexyl-diglycol (meth)acrylate, methoxy-polyethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxy-polyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, PEG200# di(meth)acrylate, PEG400# di(meth)acrylate, PEG600# di(meth)acrylate, neopentyl glycol Examples of the hydroxyl group-free (meth)acrylate (d2) include ethanol (meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. The hydroxyl group-free (meth)acrylate (d2) can be used alone or in combination of two or more.

[0038] The (meth)acrylate (d2) having no hydroxyl group preferably has two or more (meth)acryloyl groups in one molecule in order to improve the scratch resistance of the cured coating film.

[0039] Commercially available products of the (meth)acrylate (d2) having no hydroxyl group include, for example, IBXA, Viscoat #155, Viscoat #160, Viscoat #190, 2-MTA, Viscoat #200, Viscoat #196, Viscoat #195, Viscoat #230, Viscoat #260, Viscoat #310HP, and Viscoat #295 (manufactured by Osaka Organic Chemical Industry Ltd.), Miramer M100, Miramer M1080, Miramer M1084, Miramer M1110, Miramer M1122, Miramer M1130, Miramer M1140, Miramer M1142, Miramer M1162, Miramer M1182, Miramer M130, Miramer M140, Miramer M150, Miramer M164, Miramer M166, and Miramer M1182. M170, Miramer M180, Miramer M200, Miramer M204, Miramer 210, Miramer M216, Miramer M220, Miramer M222, Miramer M232, Miramer M240, Miramer M244, Miramer M2100, Miramer M2200, Miramer M2300, Miramer M262, Miramer M270, Miramer M280, Miramer M282, Miramer M284, Miramer M286, Miramer M2040, Miramer M2070, Miramer M300, Miramer M3130, Miramer M3160, Miramer M3190, Miramer M23150, Miramer M320 (manufactured by MIWON), Light Ester E, Light Ester NB, Light Ester IB, Light Ester TB, Light Ester EH, Light Ester ID, Light Ester L, Light Ester S, Light Ester BO, Light Ester BC, Light Ester 130MA, Light Ester CH, Light Ester BZ, Light Ester PO, Light Ester IB-X, Light Ester EG, Light Ester 2EG, Light Ester 3EG, Light Ester 4EG, Light Ester 9EG, Light Ester 14EG, Light Ester 1,4BG, Light Ester NP, Light Ester 1,6HX, Light Ester 1,9ND, Light Ester 1,10DC, Light Ester DCP-M, Light Ester BP-2EM, Light Ester BP-6EM, Light Acrylate IAA, Light Acrylate LA, Light Acrylate SA, Light Acrylate BO-A, Light Acrylate EC-A, Light Acrylate MTG-A, Light Acrylate 130A, Light Acrylate DPM-A, Light Acrylate MPO-A, Light Acrylate P2H-A, Light Acrylate P- 200A, Light Acrylate POB-A, Light Acrylate IB-XA, Light Acrylate 3EG-A, Light Acrylate 4EG-A, Light Acrylate 9EG-A, Light Acrylate 14EG-A, Light Acrylate PTMGA-250, Light Acrylate NP-A, Light Acrylate MPD-A, Light Acrylate 1.6HX-A, Light Acrylate 1,9ND-A, Light Acrylate DCP-A, and Light Acrylate TMP-A (manufactured by Kyoei Chemical Co., Ltd.) can be used.

[0040] The content of the (meth)acrylate (d2) having no hydroxyl group is preferably 20 to 90 mass%, more preferably 30 to 85 mass%, and particularly preferably 40 to 80 mass%, based on 100 mass% of the total solid matter of the (D) component. Furthermore, the content is preferably 10 to 65 mass%, more preferably 15 to 60 mass%, and particularly preferably 20 to 50 mass%, based on 100 mass% of the total solid matter of the composition. When the content is within the above range, wettability to the substrate is improved, and poor appearance such as repellency can be suppressed.

[0041] [Component (E): Dispersant] The composition may optionally contain a dispersant to prevent aggregation of inorganic fine particles such as component (C) and maintain affinity with photocurable compounds such as component (D). Phosphate esters, carboxylate esters, sulfate esters, and sulfonate esters are preferred dispersants because they are suitable for dispersing inorganic fine particles. Component (E) can be used alone or in combination of two or more.

[0042] The phosphate ester may be, for example, a phosphate monoester, a phosphate diester, or a phosphate triester, with phosphate monoester being particularly preferred. Commercially available phosphate ester dispersants include DISPERBYK-108, DISPERBYK-110, and DISPERBYK-111 (manufactured by BYK-Chemie) and the Phosphanol series (manufactured by Toho Chemical Industry Co., Ltd.). Commercially available carboxylic acid esters include Caribone L-400 (manufactured by Sanyo Chemical Industries Co., Ltd.). Commercially available sulfate esters include Newcol 2320-SN and Antox MS-60 (manufactured by Nippon Nyukazai Co., Ltd.). Commercially available sulfonic acid esters include Lunox 1500A (manufactured by Toho Chemical Industry Co., Ltd.).

[0043] The content of the dispersant (E) is preferably 0.5 to 10 mass %, more preferably 1 to 5 mass %, based on 100 mass % of the total solid matter of the composition. When the content is within this range, the dispersibility of the inorganic fine particles in the composition can be improved.

[0044] The composition may contain an organic solvent to adjust the viscosity when applied to a substrate. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, isopropanol, and t-butanol; esters such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and glycol ethers such as propylene glycol monomethyl ether.

[0045] In addition to the above components (A) to (E), the composition may contain additives such as photosensitizers, polymerization inhibitors, antifoaming agents, surface conditioners such as leveling agents, viscosity modifiers, light resistance stabilizers, weather resistance stabilizers, heat resistance stabilizers, ultraviolet absorbers, antioxidants, organic pigments, inorganic pigments, silica beads, and organic beads, depending on the intended use and required properties.

[0046] The composition can be produced by appropriately blending and stirring the above components (A) to (D), optional component (E), organic solvent, and other components. The order in which these components are blended is not particularly limited; the inorganic fine particles (B) and (C) may be added to the organic solvent and component (A) before component (E) is added, or the inorganic fine particles (B) and (C) may be added to the organic solvent and component (A) before component (E) is added.

[0047] [Cured coating film] The cured coating film of the present invention is a film formed by curing the above-mentioned composition. The cured coating film may be formed by applying the composition to at least one surface of a substrate such as a film and then irradiating it with active energy rays, or the cured coating film may be formed without providing a substrate.

[0048] The refractive index of the cured coating film of the present invention is preferably 1.50 or more and 1.56 or less, more preferably 1.51 or more and 1.55 or less. A coating film refractive index within this range makes it possible to form a cured coating film that can suppress the occurrence of interference fringes. The refractive index of the coating film can be adjusted by appropriately adjusting the refractive index and ratio of the components (B) and (C) used, because the influence of components (A) and (D) on the refractive index of the cured coating film is extremely small.

[0049] The material of the substrate when obtaining a cured coating film is preferably a highly transparent resin, and examples thereof include cyclic olefin copolymers; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polypropylene, polyethylene, and polymethylpentene-1; cellulose resins such as cellulose acetate (diacetyl cellulose, triacetyl cellulose, etc.), cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate butyrate, cellulose acetate phthalate, and cellulose nitrate; acrylic resins such as polymethyl methacrylate; vinyl chloride resins such as polyvinyl chloride and polyvinylidene chloride; polyvinyl alcohol; ethylene-vinyl acetate copolymer; polystyrene; polyamide; polycarbonate; polysulfone; polyethersulfone; polyetheretherketone; polyimide resins such as polyetherimide; norbornene resins (e.g., Zeonor manufactured by Zeon Corporation), and modified norbornene resins (e.g., Arton manufactured by JSR Corporation). Furthermore, a substrate made of two or more of these resins may be laminated together.

[0050] The substrate used to obtain the cured coating film may be in the form of a film or a sheet, and its thickness is preferably in the range of 1 to 500 μm. When a film-shaped substrate film is used, its thickness is preferably in the range of 200 to 200 μm, more preferably in the range of 20 to 150 μm, and even more preferably in the range of 20 to 120 μm. By setting the thickness of the film substrate within this range, curling can be easily suppressed even when a hard coating layer made of a composition is provided on one side of the film.

[0051] [film] The film of the present invention has a cyclic olefin resin film substrate or an olefin resin film substrate with the above-described cured coating film on at least one surface thereof without primer treatment or corona treatment. The cured coating film functions as a hard coat layer within the film. Conventionally, substrates such as cyclic olefin resins (COP) and olefin resin films have been considered difficult to improve substrate adhesion due to their low surface polarity, poor surface wettability, and resistance to solvent erosion due to their predominantly alicyclic structure. However, cured coating films made from the composition exhibit good adhesion to such substrates. This is because the excited state of component (A) in the composition abstracts hydrogen from component (D), generating radicals derived from component (D). These radicals then abstract hydrogen from the cycloolefin moiety of the COP substrate and bond to it, thereby contributing to improved adhesion to the substrate. Therefore, good substrate adhesion can be achieved even without pretreatment such as primer treatment or corona treatment.

[0052] Commercially available COP film substrates include, for example, ZEONOR, ZEONEX (manufactured by Zeon Corporation), ARTON (manufactured by JSR Corporation), TOPAS (manufactured by Polyplastics Co., Ltd.), APEL (manufactured by Mitsui Chemicals, Inc.), and SANUQI (manufactured by Konica Minolta, Inc.) Commercially available olefin resin film substrates include, for example, Torayfan (manufactured by Toray Industries, Inc.).

[0053] Examples of methods for applying the composition to a substrate include die coating, microgravure coating, gravure coating, roll coating, comma coating, air knife coating, kiss coating, spray coating, dip coating, spinner coating, brush coating, solid coating by silk screen, wire bar coating, and flow coating.

[0054] Examples of active energy rays that cure the composition include ultraviolet rays, electron beams, and ionizing radiation such as α-rays, β-rays, and γ-rays. When ultraviolet rays are used as the active energy rays, examples of devices that irradiate the ultraviolet rays include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, electrodeless lamps (fusion lamps), chemical lamps, black light lamps, mercury-xenon lamps, short arc lamps, helium-cadmium lasers, argon lasers, sunlight, and LED lamps.

[0055] The thickness of the cured coating film (hard coat layer in the film of the present invention) when formed on a substrate is preferably 0.1 to 25 μm, more preferably 0.3 to 15 μm, and particularly preferably 0.5 to 10 μm, because this ensures sufficient hardness of the cured coating film and can suppress curling of the film due to cure shrinkage of the coating film. [Example]

[0056] The present invention will be described in more detail below with reference to examples.

[0057] [Preparation Example 1: Method for preparing zirconia dispersion (I)] 44.0 parts by mass of UEP-100 (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) as zirconia, 7.0 parts by mass of Phosphate Ester 1 (a compound represented by the following structural formula) as phosphate ester, 4.0 parts by mass of KBM-503 (manufactured by Shin-Etsu Chemical Co., Ltd., 3-(trimethoxysilyl)propyl methacrylate) as silane coupling agent, and 100 parts by mass of methyl ethyl ketone (hereinafter abbreviated as "MEK") were mixed and stirred for 30 minutes with a dispersion stirrer to perform coarse dispersion. Next, the resulting mixture was dispersed using zirconia beads with a particle size of 100 μm in a media-type wet disperser (Star Mill LMZ-015 manufactured by Ashizawa Fine Tech Co., Ltd.). The dispersion process was performed for 100 minutes while checking the particle size during the process, and zirconia dispersion (I) was obtained. [ka] (R in the formula9 is a methyl group, and R 10 is an ethylene chain having 2 carbon atoms. In addition, x is 5, y is 2 (average value), and n is an integer of 1 to 3.

[0058] Example 1 The dispersion contained 19.0 parts by mass of Aronix M-305 (manufactured by Toagosei Co., Ltd.; hydroxyl value 120 mg KOH / g) which is pentaerythritol tri- and tetraacrylate (PETA), 5.0 parts by mass of LUXYDIR V-6840 (manufactured by DIC Corporation; hydroxyl value 240 mg KOH / g) which is a polymer acrylate, 38.0 parts by mass of Light Acrylate 1,9-ND-A (manufactured by Kyoei Chemical Co., Ltd.) which is 1,9-nonanediol diacrylate, 66.7 parts by mass (20.0 parts by mass in terms of solid content) of MEK-ST-ZL (manufactured by Nissan Chemical Industries, Ltd.; particle size 80 nm) which is a methyl ethyl ketone-dispersed silica sol, 20.0 parts by mass (solid content) of the zirconia dispersion (I) obtained in Preparation Example 1 above, 0.4 parts by mass of Runtecure 1104 as a photoinitiator, and Omnirad 4MBZ Flakes (IGM An active energy ray-curable composition (1) was prepared by uniformly mixing 3.0 parts by mass of an active energy ray-curable composition (manufactured by BYK Resins), 2.0 parts by mass of a dispersant, DISPERBYK-111 (manufactured by BYK-Chemie), and 86 parts by mass of propylene glycol monomethyl ether (PGME). The refractive index of the inorganic component in the active energy ray-curable composition (1) was calculated as follows: silica density 2.0 [g / cm 3 ], zirconia density 6.0 [g / cm 3 ]. Refractive index of inorganic component = (Refractive index of component (B): 1.45 × Volume of component (B): 20.0 / 2.0 + Refractive index of component (C): 1.8 × Volume of component (C): 20.0 / 6.0) / (Volume of component (B): 20.0 / 2.0 + Volume of component (C): 20.0 / 6.0) = 1.54

[0059] (Examples 2 to 9, Comparative Examples 1 to 9) Active energy ray-curable compositions (2) to (9) and (R1) to (R9) were obtained in the same manner as in Example 1, except that the compositions were changed to those shown in Tables 1 and 2. The refractive index of the inorganic component was also calculated in the same manner as in Example 1.

[0060] [Preparation of evaluation samples] Each composition in each example was applied to a 25 μm thick COP film (ZEONOR Film ZD-12, manufactured by Zeon Corporation) using a bar coater, and the solvent was dried for a certain period of time under a certain temperature condition. After that, the composition was applied to a 1.3 kJ / m 2 UV irradiation device (high-pressure mercury lamp, manufactured by Eye Graphics Co., Ltd.) under a nitrogen atmosphere. 2 A COP film having a cured coating film with a thickness of 2 μm was obtained.

[0061] [Coating refractive index nD] The refractive index of each of the cured coatings obtained above was measured at 594 nm using a Metricon Model 2010 prism coupler.

[0062] [Painting material and coating appearance] The cured coating film of each example obtained above was visually inspected, and any abnormalities such as whitening, lumps, repellency, or particle settling were judged to be unacceptable.

[0063] [Interference fringes] For the cured coatings obtained in each example above, with a black PET film on the backside, light was shone on the surface of the coating from a sodium lamp, and the presence or absence of interference fringes was visually observed and rated as A, B, or C below. A grade of B or higher was considered a pass. A: No interference fringes are visible. B: Interference fringes are partially visible. C: Interference fringes are clearly visible.

[0064] [Substrate adhesion evaluation] Eleven vertical and horizontal cuts were made at 1 mm intervals on the surface of the cured coating of each COP film, creating a grid of 100 squares. Cellophane tape (Nichiban Co., Ltd.'s "Cellotape (registered trademark) CT-18") was then adhered to the surface and then quickly peeled off twice. The initial adhesion was evaluated based on the percentage of the remaining area that remained unpeeled, according to the following criteria. A rating of B or higher was deemed acceptable. A: The remaining area ratio is 100%. B: The remaining area ratio is 95% or more but less than 100%. C: The remaining area ratio is 10% or more and less than 95%. D: The remaining area ratio is less than 10%.

[0065] [Scratch resistance evaluation] The surface of the cured coating film of each COP film example was tested using a crockmeter-type friction tester (circular friction probe 1.0 cm in diameter, steel wool #0000, load 250 g, 10 reciprocations), and the presence or absence of scratches on the surface of the cured coating film after the test was visually observed.

[0066] [Table 1]

[0067] [Table 2]

[0068] The abbreviations shown in Tables 1 and 2 represent the following compounds: MEK-ST-L: Silica sol dispersed in methyl ethyl ketone; Nissan Chemical Co., Ltd. MEK-AC-4130Y; Silica sol dispersed in methyl ethyl ketone; Nissan Chemical Co., Ltd. Aronix M-920; glycerin di / triacrylate; manufactured by Toagosei Co., Ltd. Aronix M-450; pentaerythritol tri- and tetraacrylate (PETTA); manufactured by Toagosei Co., Ltd. Light Acrylate DCP-A; Dimethylol-tricyclodecane diacrylate; Kyoeisha Chemical Co., Ltd.

[0069] It was confirmed that the cured coating films of the active energy ray-curable compositions of the present invention in Examples 1-9 had no abnormalities in the coating film appearance, no interference fringes, excellent substrate adhesion with the COP film, and excellent scratch resistance. On the other hand, in Comparative Example 1, which did not contain the (B) component and contained only zirconia (C), the refractive index of the inorganic component was not in the range of 1.46 or more and less than 1.68, and interference fringes occurred. In Comparative Examples 2 and 3, which did not contain the (C) component and contained only silica (B), the refractive index of the inorganic component was not in the range of 1.46 or more and less than 1.68, and interference fringes occurred. Similarly, in Comparative Example 4, which contained only silica, the adhesion to the substrate was poor. In Comparative Example 5, which did not contain the inorganic particles (B) and (C), the wettability to the substrate deteriorated, repellency occurred, and scratch resistance was not obtained. Furthermore, in Comparative Examples 6 and 7, which did not contain the (d1) component, the absence of a hydrophilic resin resulted in poor particle dispersibility, and the particles settled when the coating was formed. In Comparative Example 8, which did not contain the (d2) component, the resin was too hydrophilic, and the wettability to the substrate deteriorated, resulting in repellency.

Claims

1. An active energy ray-curable composition comprising the following components (A) to (D), wherein the refractive index of the inorganic component determined by the following formula (1) is 1.46 or more and less than 1.68: Component (A): Photoinitiator Component (B): inorganic fine particles having a refractive index of less than 1.53 Component (C): inorganic fine particles having a refractive index of 1.53 or more Component (D): (meth)acrylate (d1) having a hydroxyl group and (meth)acrylate (d2) not having a hydroxyl group Formula (1): (Refractive index of component (B) × Volume of component (B) + Refractive index of component (C) × Volume of component (C)) / (Volume of component (B) + Volume of component (C))

2. 2. The active energy ray-curable composition according to claim 1, wherein component (B) contains silica fine particles having an average primary particle diameter in the range of 10 nm or more and 150 nm or less.

3. 2. The active energy ray-curable composition according to claim 1, wherein component (C) comprises fine zirconia or titania particles having an average primary particle size in the range of 10 nm to 100 nm.

4. 2. The active energy ray-curable composition according to claim 1, wherein the component (A) comprises a hydrogen abstraction photoinitiator.

5. 2. The active energy ray-curable composition according to claim 1, wherein the component (E) is any one dispersant selected from the group consisting of phosphate esters, carboxylate esters, sulfate esters, and sulfonate esters.

6. 2. The active energy ray-curable composition according to claim 1, wherein the component (d1) comprises a polyfunctional acrylate having a hydroxyl value of 80 mgKOH / g or more.

7. 2. The active energy ray-curable composition according to claim 1, wherein the total content of the components (B) and (C) is 10 to 80 mass % relative to 100 mass % of all solids in the composition.

8. A cured coating film of the active energy ray-curable composition according to any one of claims 1 to 7.

9. 9. The cured coating film according to claim 8, having a refractive index of 1.50 or more and 1.56 or less.

10. A cyclic olefin resin film substrate, or a film having the cured coating film according to claim 8 on at least one surface of an olefin resin film substrate without primer treatment or corona treatment.

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