Active energy ray curable composition and its cured product
The active energy ray-curable composition with zirconia particles and biphenylmethyl (meth)acrylate addresses the flexibility and durability issues of high refractive index materials, offering self-healing and low viscosity solutions for optical films and sheets.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DIC CORP
- Filing Date
- 2024-12-25
- Publication Date
- 2026-07-07
AI Technical Summary
Existing materials with high refractive indices for optical functional layers in displays tend to reduce flexibility, leading to chipping and a lack of self-healing properties, which is problematic for thinner displays with improved brightness and viewing angles.
An active energy ray-curable composition comprising inorganic particles, a (meth)acrylate compound, and a photopolymerization initiator, with specific parameters and ranges for SdCH2, SaasC, MaxEStateIndex, and SssCH2, utilizing zirconia particles and biphenylmethyl (meth)acrylate to achieve high refractive index, low viscosity, and good self-healing properties.
The composition provides a cured product with enhanced self-healing capabilities, high refractive index, and low viscosity, suitable for shaping optical films and optical sheets, addressing the flexibility and durability issues of previous materials.
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Abstract
Description
[Technical Field]
[0001] The present invention relates to an active energy ray curable composition and its cured product. [Background technology]
[0002] In recent years, optical sheets that provide functions such as improved brightness and expanded viewing angles have been used in displays such as liquid crystal displays. Such optical sheets typically consist of a substrate and an optical functional layer having a fine uneven structure on the substrate. The desired function is achieved by modulating light through geometric optical effects such as refraction at the uneven shape. Since such uneven shapes are mainly manufactured by shaping resin materials using metal molds, the material used for the optical functional layer is required to be solvent-free and have low viscosity. Furthermore, among the optical sheets mentioned above, prism sheets, for example, have a pointed convex shape, making them prone to chipping due to contact with adjacent components. In such cases, flexibility and self-healing properties are particularly required. On the other hand, with the trend towards thinner displays and reduced power consumption, the materials used in the optical functional layers are required to have high refractive indices. To address this, methods have been proposed that involve using monofunctional (meth)acrylates with high refractive indices and low viscosity, or by adding organic or inorganic high refractive index fine particles (for example, Patent Documents 1-3). [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] International Publication No. 2020 / 250721 [Patent Document 2] Japanese Patent Publication No. 2013-249439 [Patent Document 3] Japanese Patent Publication No. 2010-85539 [Overview of the Initiative] [Problems that the invention aims to solve]
[0004] However, materials with a high refractive index generally reduce the flexibility of the cured resin, resulting in a problem that chipping of the uneven shape is likely to occur. Therefore, there has been a demand for a material having good self-healing properties, a high refractive index, and a low viscosity.
[0005] The present invention has been made to solve the above problems, and an object thereof is to provide an active energy ray-curable composition having good self-healing properties, a high refractive index, and a low viscosity, and a cured product thereof.
Means for Solving the Problems
[0006] The content of the present disclosure includes the following embodiments. [1] An active energy ray-curable composition containing inorganic particles (A), a (meth)acrylate compound (B), and a photopolymerization initiator (C), where the content of the inorganic particles (A) in the active energy ray-curable composition is 30% by mass or more and 60% by mass or less, the value of parameter SdCH2 generated from the composition of the active energy ray-curable composition is 3.00 to 10.00, the value of parameter SaasC generated from the composition of the active energy ray-curable composition is 0.00 to 6.00, the value of parameter MaxEStateIndex generated from the composition of the active energy ray-curable composition is 14.00 to 28.00, An active energy ray-curable composition in which the value of parameter SssCH² generated from the composition of the active energy ray-curable composition is 0.00 to 5.00. The parameter SdCH2 is a value calculated using SdCH2 (compound) of each component contained in the active energy ray-curable composition, and the SdCH2 (compound) is a parameter obtained by the following formula (1). SdCH2 (compound) = Σ EState value of "=CH2" structure in the molecule (1) The parameter SaasC is a value calculated using SaasC (compound) of each component contained in the active energy ray curable composition, and the SaasC (compound) is a parameter obtained by the following formula (2). The "=CH2 structure" refers to a structure having three σ bonds and one π bond and including a carbon atom bonded to two hydrogen atoms. Examples of compounds having the "=CH2 structure" include ethylene, acetylene, styrene, allyl compounds, methyl (meth) acrylate, and the like. SaasC (compound) = Σ EState value of "aCa-" structure in the molecule (2) The parameter MaxEStateIndex is a value calculated using MaxEStateIndex (compound) of each component contained in the active energy ray curable composition, and the MaxEStateIndex (compound) is a parameter obtained by the following formula (3). The "aCa-" structure refers to a structure including a carbon atom bonded to an aromatic ring. Examples of compounds having the "aCa-" structure include biphenyl, toluene, styrene, and the like. MaxEStateIndex = maximum EState value in the molecule (3) The parameter SssCH2 is a value calculated using SssCH2 (compound) of each component contained in the active energy ray curable composition, and the SssCH2 (compound) is a parameter obtained by the following formula (4). SssCH2 = Σ EState value of "-CH2-" structure in the molecule (4) The "-CH2-" structure refers to a structure having four σ bonds, no π bond, and including a carbon atom bonded to two hydrogen atoms. Examples of compounds having the "-CH2-" structure include ethane, octane, ethanol, polyethylene glycol, stearic acid, and the like. [2] The active energy ray curable composition according to [1], wherein the inorganic particles (A) are zirconia. [3] The active energy ray curable composition according to [1] or [2], wherein the particle diameter of the inorganic particles (A) measured by the dynamic light scattering method is 1 to 100 nm. [4] An active energy ray curable composition according to any one of [1] to [3], wherein the (meth)acrylate compound (B) contains a biphenyl structure. [5] An active energy ray curable composition according to any one of [1] to [4], wherein the (meth)acrylate compound (B) contains biphenylmethyl (meth)acrylate. [6] An active energy ray curable composition according to any one of [1] to [5], wherein the active energy ray curable composition is for use in shaped optical films. [7] A cured product of an active energy ray curable composition as described in any of [1] to [6]. [8] [7] A shaped optical film containing the cured product described above. [9] An optical sheet containing the cured material described in [7]. [Effects of the Invention]
[0007] According to the present invention, it is possible to provide an active energy ray curable composition and its cured product, which has good self-healing properties and high refractive index and low viscosity. [Brief explanation of the drawing]
[0008] [Figure 1] Figure 1 illustrates the method for measuring elastic deformation power (nIT). [Modes for carrying out the invention]
[0009] The present invention will be described in more detail below. However, the present invention is not limited to the embodiments shown below.
[0010] The symbol "~" indicates a value greater than or equal to the value before the "~" and a value less than or equal to the value after the "~". "(Meth)acrylic" is a general term for acrylic and methacrylic, and "(Meth)acrylate compound (B)" is a general term for acrylate compound and methacrylate compound.
[0011] (Active energy ray curable composition) The active energy ray-curable composition according to this embodiment contains inorganic particles (A), a (meth)acrylate compound (B), and a photopolymerization initiator (C). The content of the inorganic particles (A) in the active energy ray-curable composition is 30% by mass or more and 60% by mass or less. The value of the parameter SdCH2 generated from the composition of the active energy ray-curable composition is 3.00 to 10.00. The value of the parameter SaasC generated from the composition of the active energy ray-curable composition is 0.00 to 6.00. The value of the parameter MaxEStateIndex generated from the composition of the active energy ray-curable composition is 14.00 to 28.00. The value of the parameter SssCH2 generated from the composition of the active energy ray-curable composition is 0.00 to 5.00.
[0012] The parameter SdCH2 is a value calculated using the SdCH2 of each compound in the composition (hereinafter referred to as "SdCH2(compound)"). SdCH2(compound) is the sum of the EState values of the "=CH2" structure in one molecule and is expressed by the following formula (1). The method for calculating the parameter SdCH2 will be explained in detail later. The "=CH2 structure" refers to a structure that contains a carbon atom bonded to two hydrogen atoms, with three σ bonds and one π bond. Examples of compounds that have the "=CH2" structure include ethylene, acetylene, styrene, allyl compounds, and methyl (meth)acrylates.
[0013] SdCH2 (compound) =Σ EState value of the "=CH2" structure within the molecule (1)
[0014] The aforementioned parameter SaasC is a value calculated using the SaasC of each compound in the composition (hereinafter referred to as "SaasC(compound)"). SaasC(compound) is the sum of the EState values of the "aCa-" structure in one molecule and is expressed by the following formula (2). The method for calculating the parameter SaasC will be explained in detail later.
[0015] SaasC(compound) = EState value of the "aCa-" structure within the Σ molecule (2) The term "aCa-" refers to a structure that includes a carbon atom bonded to an aromatic ring. Examples of compounds having an "aCa-" structure include biphenyl, toluene, and styrene.
[0016] The parameter MaxEStateIndex is a value calculated using the MaxEStateIndex of each compound in the composition (hereinafter referred to as "MaxEStateIndex(compound)"). MaxEStateIndex(compound) is the maximum Estate value within the molecule and is a parameter obtained by the following equation (3). The method for calculating the parameter MaxEStateIndex will be explained in detail later.
[0017] MaxEStateIndex(compound) = the maximum Estate value within the molecule (3)
[0018] The parameter SssCH2 is a value calculated using the SssCH2 of each compound in the composition (hereinafter referred to as SssCH2(compound)). SssCH2(compound) is the sum of the EState values of the "-CH2-" structure in one molecule, and is a parameter obtained by the following equation (3). The method for calculating the parameter SssCH2 will be explained in detail later.
[0019] SssCH2(compound) = EState value of the "-CH2-" structure (4) The "-CH2-" structure refers to a structure that has four σ bonds, no π bonds, and contains a carbon atom bonded to two hydrogen atoms. Examples of compounds that have a "-CH2-" structure include ethane, octane, ethanol, polyethylene glycol, and stearic acid.
[0020] "The parameters generated from the composition of the active energy ray curable composition" are the weighted sum of the molal concentrations of the compounds constituting the composition multiplied by 1000. In addition, inorganic particles (A) are not included in the weighted sum, while other organic components (including (meth)acrylate compounds (B), photopolymerization initiators (C), and other dispersants, additives, initiators, solvents, etc.) are included.
[0021] [Parameter SdCH2 Unit: mmol / g] The parameter SdCH2 that defines the active energy ray curable composition of this embodiment is obtained from the SdCH2 (compound) of each compound that constitutes the active energy ray curable composition of this embodiment and the composition ratio of each compound. For example, the active energy ray curable composition consists of each compound component a1 to a n Includes each component a1~a n The molar content per gram of total compound (value obtained by dividing the weight ratio by the molecular weight) is p1~p n Each component a1~a n From the compound structure, each SdCH2 (compound) can be calculated (b1~b n ). Furthermore, the parameter SdCH2 of the active energy ray curable composition is calculated as shown in formula (4) below, for each component's SdCH2 (compound), the content p1~p n This is the weighted sum multiplied by 1000, with weights assigned accordingly.
[0022] SdCH2=(Σb n ×p n ) × 1000 (4)
[0023] The "=CH2" structure indicates a double bond. In particular, resins with unsaturated double bonds harden by undergoing polymerization reactions using radicals and cations generated by ultraviolet irradiation as initiators. Examples of compounds with the "=CH2" structure include ethylene, acetylene, styrene, allyl compounds, and methyl (meth)acrylates. The "aCa-" structure refers to a branched structure bonded to an aromatic ring. Examples of compounds containing the "aCa-" structure include phenol, styrene, and benzyl acrylate. The "-CH2-" structure refers to the structure from which two hydrogens are removed from methane, that is, the methylene group. Examples of compounds having the "-CH2-" structure include propane, polyethylene glycol, and hydroxybutyl acrylate.
[0024] Also, "Estate" is a value calculated by combining the electronegativity of atoms in a molecule, the Intrinsic value (I), information on the chemical stability according to its chemical environment, and the Perturbation term (ΔI). Generally, the larger the value, the greater the tendency for the polarizability to be larger.
[0025] Estate = I i + ΔI i
[0026] Here, I is calculated by the following formula. I i =((2 / N)^2×(Z v -h)+1) / (σ-h) N: principal quantum number, Z v : number of valence electrons, h: number of bonds with hydrogen atoms, σ: number of σ orbital electrons ΔI i is calculated by the following formula. ΔI i =Σ(I i -I j ) / r ij ^2 r ij : number of bonds between atom i and atom j in the molecule
[0027] Also, "Estate" is, for example, as described in a non-patent document (J. Chem. Inf. Comput. Sci. 1991, 31, 76-82), a value calculated by combining the electronegativity of atoms in a molecule, the Intrinsic value (I), information on the chemical stability according to its chemical environment, and the Perturbation term (ΔI). Generally, the larger the value, the greater the tendency for the polarizability to be larger.
[0028] For example, in Example 1 described later, the parameter SdCH2 was 6.73. This value was calculated from the composition shown in Table 1 according to formula (4) as follows.
[0029] Parameter SdCH2 (Example 1) ={(UEP-100: not added)+(Dispersant (1): 3.26×0.095÷438.41)+(KBM-503: 3.49×0.103÷248.35)+(Photomer 4035: 3.28×0.104÷192.21)+(KOMERATE A008: 3.35×0.078÷254.29)+(KOMERATE A014: 3.28×0.104÷192.21)+(Runtecure 1104: 0×0.01÷204.27)+(Omnirad 819: 0×0.005÷418.47)}×1000 =6.73
[0030] The SdCH2(compound) of each component compound, including the active energy ray curable composition of this embodiment, may be calculated from the molecular structure of each compound, for example, using software for calculating molecular descriptors. Examples of such software include Dragon (version 7.0) and alvaDesc.
[0031] The SdCH2 parameter of the active energy ray curable composition in this embodiment is preferably 3.00 or higher, more preferably 4.00 or higher, and more preferably 5.00 or higher. It is also preferably 10.00 or lower, more preferably 8.50 or lower, and more preferably 6.00 or lower. By setting the parameter within these ranges, it is possible to achieve both good self-healing properties, low viscosity, and a high refractive index.
[0032] [Parameter SaasC Unit: mmol / g] The parameter SaasC, which limits the active energy ray curable composition of this embodiment, is obtained by using the same method as for the parameter SdCH2 above, and multiplying the weighted sum by 1000 by the content of each component, based on the SaasC (compound) of each compound constituting the active energy ray curable composition of this embodiment and the composition ratio of each compound. An "aromatic bond" refers to a covalent bond formed when carbon atoms within an aromatic ring share a pair of electrons. Examples of compounds containing aromatic bonds include benzene, phenol, and styrene.
[0033] The SaasC (compound) of each component compound, including the active energy ray curable composition of this embodiment, may be calculated from the molecular structure of each compound, for example, using software for calculating molecular descriptors. Examples of such software include Dragon (version 7.0) and alvaDesc.
[0034] The SaasC parameter of the active energy ray curable composition of this embodiment is preferably 0.00 or higher, more preferably 0.50 or higher, and more preferably 1.00 or higher. It is also preferably 6.00 or lower, more preferably 5.00 or lower, and more preferably 4.00 or lower. By setting it within these ranges, good self-healing properties, low viscosity, and high refractive index can be achieved simultaneously.
[0035] [Parameter MaxEStateIndex Unit: mmol / g] The parameter MaxEStateIndex, which limits the active energy ray curable composition of this embodiment, is obtained by multiplying the weighted sum by 1000 by the MaxEStateIndex(compound) and composition ratio of each compound constituting the active energy ray curable composition of this embodiment, weighted according to the content of each component, using the same method as for the parameter SdCH2 described above.
[0036] The MaxEStateIndex(compound) of each component compound, including the active energy ray curable composition of this embodiment, may be calculated from the molecular structure of each compound using, for example, software for calculating molecular descriptors. Examples of such software include Dragon (version 7.0) and alvaDesc.
[0037] The MaxEStateIndex parameter of the active energy ray curable composition of this embodiment is preferably 14.00 or higher, more preferably 16.00 or higher, and more preferably 18.00 or higher. It is also preferably 28.00 or lower, more preferably 27.00 or lower, and more preferably 26.00 or lower. By setting it within these ranges, good self-healing properties, low viscosity, and high refractive index can be achieved simultaneously.
[0038] [Parameter SssCH2 Unit: mmol / g] The parameter SssCH2 that limits the active energy ray curable composition of this embodiment is obtained by using the same method as for the parameter SdCH2 above, and multiplying the weighted sum by 1000 by the content of each component, based on the SssCH2 (compound) and composition ratio of each compound that constitute the active energy ray curable composition of this embodiment.
[0039] The SssCH2(compound) of each component compound, which is also included in the active energy ray curable composition of this embodiment, may be calculated from the molecular structure of each compound, for example, using software for calculating molecular descriptors. Examples of such software include Dragon (version 7.0) and alvaDesc.
[0040] The parameter SssCH2 of the active energy ray curable composition of this embodiment is preferably 0.00 or higher, more preferably 0.50 or higher, and more preferably 1.00 or higher. It is also preferably 6.00 or lower, more preferably 5.00 or lower, and more preferably 4.00 or lower. By setting it within these ranges, good self-healing properties, low viscosity, and high refractive index can be achieved simultaneously.
[0041] [Inorganic particles (A)] It is preferable that the inorganic particles (A) in this embodiment are one or more selected from the group consisting of zirconia, silica, barium sulfate, zinc oxide, barium titanate, cerium oxide, alumina, and titanium oxide. It is more preferable that the inorganic particles (A) in this embodiment are zirconia. The inorganic particles (A) in this embodiment are not particularly limited in terms of their crystal structure, but for example, if they are zirconia, a monoclinic crystal system is preferred because it provides excellent dispersion stability and yields a cured product with high light transmittance and refractive index.
[0042] The inorganic particles (A) in this embodiment can be any commonly known type, and the shape of the particles is not particularly limited, but may be spherical, hollow, porous, rod-shaped, plate-shaped, fibrous, or amorphous. Among these, spherical particles are preferred because they have excellent dispersion stability and yield a cured product with high light transmittance and refractive index.
[0043] The average particle size of the inorganic particles (A) in this embodiment is preferably 100 nm or less, more preferably in the range of 1 to 100 nm, and even more preferably in the range of 20 to 100 nm, since the cured product has a high refractive index and excellent light transmittance. The above particle size was measured by dynamic light scattering.
[0044] Furthermore, the content of the inorganic particles (A) in the active energy ray curable composition is 30% by mass or more and 60% by mass or less. The content of the inorganic particles (A) in the active energy ray curable composition is 30% by mass or more, preferably 35% by mass or more, and more preferably 40% by mass or more. Also, it is 60% by mass or less, preferably 55% by mass or less, and more preferably 50% by mass or less. By setting it within these ranges, good self-healing properties and low viscosity can be achieved simultaneously.
[0045] <Zirconia nanoparticles> The inorganic particles (A) in this embodiment are more preferably zirconia nanoparticles. The zirconia nanoparticles can be those that are generally known, and the shape of the particles 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 zirconia 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 possible measurement method is to measure the short axis diameter and long axis diameter of the primary particles of individual inorganic particles and take their average as the average primary particle diameter. Specific examples of zirconia 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.
[0046] [(meth)acrylate compound (B)] Examples of the (meth)acrylate compound (B) according to this embodiment include conventionally known monofunctional (meth)acrylates or polyfunctional (meth)acrylates having (meth)acryloyl groups or (meth)acryloyloxy groups for optical sheet formation. Oligomers or prepolymers can be used as needed. The (meth)acrylate compound (B) according to this embodiment preferably comprises a monofunctional (meth)acrylate having one active energy ray curable group and a polyfunctional (meth)acrylate having two or more active energy ray curable groups. The active energy ray curable group is preferably a (meth)acryloyl group. The (meth)acrylate compound (B) according to this embodiment preferably contains a biphenyl structure, and more preferably contains biphenylmethyl (meth)acrylate. Furthermore, the (meth)acrylate compound (B) according to this embodiment does not contain a dispersant (D) having a (meth)acryloyl group, or a silane coupling agent (E) having a (meth)acryloyl group and a (meth)acryloyloxy group.
[0047] <Monofunctional (meth)acrylate> The monofunctional (meth)acrylate is a monofunctional (meth)acrylate having one active energy ray curable group, and may be a chain-like aliphatic or cyclic alicyclic or aromatic (meth)acrylate containing heteroatoms such as halogen atoms, sulfur atoms, oxygen atoms, or nitrogen atoms. For example, the monofunctional (meth)acrylate described in Patent Document 1 above can be used.
[0048] Examples of the monofunctional (meth)acrylate include aromatic mono(meth)acrylate compounds, aliphatic mono(meth)acrylate compounds, alicyclic mono(meth)acrylate compounds, heterocyclic mono(meth)acrylate compounds, and hydroxyl group-containing mono(meth)acrylate compounds. Furthermore, examples of the monofunctional (meth)acrylate include polyoxyalkylene-modified mono(meth)acrylate compounds obtained by introducing polyoxyalkylene chains such as polyoxyethylene chains, polyoxypropylene chains, and polyoxytetramethylene chains into the molecular structure of the various mono(meth)acrylate compounds; and lactone-modified mono(meth)acrylate compounds obtained by introducing a (poly)lactone-derived structure into the molecular structure of the various mono(meth)acrylate compounds.
[0049] Examples of the aromatic mono(meth)acrylate compounds include benzyl(meth)acrylate, phenyl(meth)acrylate, phenoxy(meth)acrylate, phenoxyethyl(meth)acrylate, phenoxyethoxyethyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, phenoxybenzyl(meth)acrylate, biphenylmethyl(meth)acrylate, benzylbenzyl(meth)acrylate, phenylphenoxyethyl(meth)acrylate, phenylphenol(EO)n(meth)acrylate, and phenol(EO)n(meth)acrylate.
[0050] Examples of the aliphatic mono(meth)acrylate compounds include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, tert-butyl(meth)acrylate, n-pentyl(meth)acrylate, n-hexyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, and 2-ethylhexyl(meth)acrylate. Examples of the alicyclic mono(meth)acrylate compounds include cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, adamantylmono(meth)acrylate, cyclohexylmethyl(meth)acrylate, cyclohexylethyl(meth)acrylate, dicyclopentanyl(meth)acrylate, dicyclopentanyloxyethyl(meth)acrylate, dicyclopentenyl(meth)acrylate, and dicyclopentenyloxyethyl(meth)acrylate. Examples of the heterocyclic mono(meth)acrylate compounds include glycidyl(meth)acrylate and tetrahydrofurfurylacrylate. Examples of the hydroxyl group-containing mono(meth)acrylate compounds include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Examples of the lactone-modified mono(meth)acrylate compound include caprolactone-modified tetrahydrofurfuryl(meth)acrylate.
[0051] The monofunctional (meth)acrylate preferably contains an aromatic mono(meth)acrylate compound, and more preferably contains a compound containing two aromatic rings in one molecule. The compound containing two aromatic rings in one molecule is particularly preferably biphenylmethyl (meth)acrylate. Examples of compounds containing two aromatic rings in one molecule (aromatic mono(meth)acrylate compounds) include phenoxybenzyl(meth)acrylate, biphenylmethyl(meth)acrylate, benzylbenzyl(meth)acrylate, phenylphenoxyethyl(meth)acrylate, phenylphenol(EO)n(meth)acrylate, and (1-naphthyl)methyl acrylate.
[0052] Specific examples of the monofunctional (meth)acrylates mentioned above include, for example, the following monofunctional (meth)acrylates used in the examples. Compound (B1-1): Orthophenylphenol (EO) acrylate, trade name: KOMERATE A011 (manufactured by Green Chemical Co., Ltd.) Compound (B1-2): Biphenyl methyl acrylate, trade name: MIRAMER M1192 (manufactured by MIWON SPECIALTY CHEMICAL CO., LTD.) Compound (B1-3): 3-Phenoxybenzyl acrylate, trade name: KOMERATE A008 (manufactured by Green Chemical Co., Ltd.) Compound (B1-4): (1-Naphthyl)methyl acrylate, trade name: Light Acrylate NMT-A (manufactured by Kyoei Chemical Co., Ltd.) Compound (B1-5): Phenoxyethyl acrylate, trade name: Photomer 4035 (manufactured by IGM Resins Inc.) Compound (B1-6): Benzyl acrylate, trade name: MIRAMER M1182 (manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD.)
[0053] The aforementioned monofunctional (meth)acrylate may be used alone or in combination of two or more types. The content of the monofunctional (meth)acrylate in the (meth)acrylate compound (B) may be 70% by mass, 75% or more by mass, 80% or more by mass, or 85% or more by mass. It may also be 95% or less by mass, or 90% or less by mass. When the content of the monofunctional (meth)acrylate is within the above range, it has good self-healing properties and high refractive index and low viscosity.
[0054] When the monofunctional (meth)acrylate contains a compound (aromatic mono(meth)acrylate compound) that has two aromatic rings in one molecule, such as biphenylmethyl (meth)acrylate, the content of the compound containing two aromatic rings in one molecule, such as biphenylmethyl (meth)acrylate, in the monofunctional (meth)acrylate is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. Furthermore, the content of the above compound is not particularly limited, and a higher value is preferable. If we had to specify, from the viewpoint of self-healing properties, it is preferably 95% by mass or less, and more preferably 90% by mass or less. Furthermore, when the compound containing two aromatic rings within one molecule in the monofunctional (meth)acrylate is biphenylmethyl (meth)acrylate, it exhibits particularly excellent adhesion to the substrate in addition to refractive index, viscosity, and self-healing properties.
[0055] [Multifunctional (meth)acrylate] The (meth)acrylate compound (B) according to this embodiment may include a polyfunctional (meth)acrylate in addition to the monofunctional (meth)acrylate according to this embodiment.
[0056] The polyfunctional (meth)acrylate is preferably a polyfunctional (meth)acrylate having three or more active energy ray curable groups. It may also be a chain-like aliphatic or cyclic alicyclic or aromatic (meth)acrylic acrylate containing heteroatoms such as halogen atoms, sulfur atoms, oxygen atoms, or nitrogen atoms. For example, the polyfunctional (meth)acrylate described in Patent Document 1 above can be used.
[0057] Examples of the polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, tetrabutylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Rate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, glycerol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, caprolactone modified hydroxypivalate neopentyl glycol di(meth)acrylate, tetrabromobisphenol A di(meth)acrylate, hydropivalaldehyde modified trimethylolpropane di(meth)acrylate, bisphenol fluoren (meth)acrylate, bisphenol fluorene (EO) n Di(meth)acrylate, bisphenol A(EO) n Di(meth)acrylate, trimethylolpropane (EO) n Examples of polyfunctional (meth)acrylates include tri(meth)acrylate, 1,4-cyclohexanedimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol tri(meth)acrylate, alkyl-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetra(meth)acrylate, epoxy(meth)acrylate, urethane(meth)acrylate, and polyester(meth)acrylate.
[0058] These polyfunctional (meth)acrylates can be used individually or in combination of two or more. Among these, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ditrimethylolpropanetetra(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.
[0059] An example of a polyfunctional (meth)acrylate according to this embodiment is a mixture of a polyfunctional (meth)acrylate having three active energy ray curable groups and a polyfunctional (meth)acrylate having four active energy ray curable groups. A specific example is a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (containing approximately 30-70% by mass of the tri-isomer and approximately 70-30% by mass of the tetra-isomer). An example of such a mixture is "Arronix M-305" (manufactured by Toagosei Co., Ltd., a reaction product of pentaerythritol and acrylic acid, containing approximately 60% of the tri-isomer, with a hydroxyl value of 116 mgKOH / g) used in the example.
[0060] [Photopolymerization initiator (C)] The photopolymerization initiator (C) according to this embodiment is not particularly limited as long as it has the function of initiating the polymerization of (meth)acryloyl groups such as the (meth)acrylate compound (B) according to this embodiment by photoexcitation. Examples include intramolecular bond cleavage type photopolymerization initiators (C) and intramolecular hydrogen abstraction type photopolymerization initiators (C). For example, monocarbonyl compounds, dicarbonyl compounds, acetophenone compounds, benzoin ether compounds, acylphosphine oxide compounds, aminocarbonyl compounds, etc., can be used.
[0061] Examples of the intramolecular bond cleavage type photopolymerization initiator (C) 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; benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acylphosphine oxide derivatives such as 2,4,6-trimethylbenzoindiphenylphosphine oxide; and benzyl and methylphenylglyoxyesters.
[0062] Examples of the intramolecular hydrogen abstraction type photopolymerization initiator (C) include benzophenone-based compounds 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; thioxanthone-based compounds such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothiooxanthone; aminobenzophenone-based compounds such as Mihila-ketone and 4,4′-diethylaminobenzophenone; and 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, and camphorquinone. The photopolymerization initiator (C) is preferably 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
[0063] Examples of commercially available photopolymerization initiators (C) include Omnirad-184, 651, 500, 907, 127, 369, 784, 2959, TPO-H, and Omnirad 819 from IGM-Resins; and Esacure ONE from DKSH Japan Co., Ltd. From the viewpoint of obtaining a cured coating film with excellent curability even with a small amount of additive, Omnirad 819 is preferred. From the viewpoint of minimal discoloration, Omnirad-184 is particularly preferred.
[0064] The photopolymerization initiator (C) is not limited to the above-mentioned compound, but can be any substance that has the ability to initiate polymerization by ultraviolet light. These photopolymerization initiators (C) may be used individually or in combination of two or more types. There are no particular restrictions on the amount of the photopolymerization initiator (C) used, but it is preferable to use it in the range of 0.1 to 10 parts by mass, and more preferably in the range of 1 to 5 parts by mass, per 100 parts by mass of the total nonvolatile content of the active energy ray curable 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.
[0065] A specific example of the photopolymerization initiator (C) according to this embodiment is Runtecure 1108 (manufactured by Runtec Chemical Co., Ltd., structural formula or compound name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide).
[0066] The content of the photopolymerization initiator (C) is preferably 0.1 to 10% by mass, and more preferably 0.5 to 5% by mass, relative to the mass of the nonvolatile content of the composition. The non-volatile content mass of a composition is the total mass of all components of the composition after removing the solvent contained in the composition.
[0067] [Dispersant (D)] The active energy ray curable composition of this embodiment preferably further contains a dispersant (D) (sometimes referred to as "component (D)"), and more preferably the dispersant (D) contains a phosphate ester.
[0068] <Phosphate esters> The phosphate ester according to this embodiment is not particularly limited, but examples include those having a polyester chain and those having a (meth)acryloyl group. Examples of products containing polyester chains include DISPERBYK-110 and DISPERBYK-111 (manufactured by Bic Chemie Japan Co., Ltd.).
[0069] Furthermore, examples of materials having a (meth)acryloyl group include those represented by the following structural formula (1), because the resulting inorganic particle dispersion has excellent dispersion stability, and the curable composition containing it has low viscosity, allowing for the formation of a cured coating film with high refractive index performance and excellent bleed-out resistance.
[0070] [ka] (R in the formula 1 R is a hydrogen atom or a methyl group, 2 This is an alkylene chain with 2 to 4 carbon atoms. Also, x is an integer between 4 and 10, y is an integer greater than or equal to 1, and n is an integer between 1 and 3.
[0071] The phosphate ester compound represented by the above structural formula (1) can form a cured coating film with low viscosity, high refractive index performance, and excellent bleed-out resistance, resulting in an active energy ray curable composition. Therefore, x in the formula is preferably 4 or 5, and y is preferably an integer from 2 to 7. Furthermore, the dispersant (D) represented by the above structural formula (1) (hereinafter sometimes simply referred to as dispersant (1)) may also have a mixture of n in the formula of 1, 2, and / or 3.
[0072] In the active energy ray curable composition, the content of the phosphate ester compound is more preferably in the range of 5 to 40 parts by mass, and even more preferably in the range of 10 to 25 parts by mass, per 100 parts by mass of zirconia, in order to form a cured coating film with high refractive index performance and excellent bleed-out resistance.
[0073] [Silane coupling agent (E)] The active energy ray curable composition of this embodiment may further contain a silane coupling agent (E) (sometimes referred to as "component (E)"). Examples of the silane coupling agent (E) according to this embodiment include (meth)acryloyloxy silane coupling agents such as 3-(meth)acryloyloxypropyltrimethylsilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, and 3-(meth)acryloyloxypropyltriethoxysilane; Vinyl silane coupling agents such as allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, diethoxymethylvinylsilane, trichlorovinylsilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(2-methoxyethoxy)silane; Epoxy silane coupling agents such as diethoxy(glycidyloxypropyl)methylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; Styrene-based silane coupling agents such as p-styryltrimethoxysilane; Amino-based silane coupling agents such as 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; Ureidopropyltriethoxysilane and other ureido-based silane coupling agents; Chloropropyl silane coupling agents such as 3-chloropropyltrimethoxysilane; mercapto-silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; Sulfide-based silane coupling agents such as bis(triethoxysilylpropyl)tetrasulfide; Isocyanate-based silane coupling agents such as 3-isocyanate-propyltriethoxysilane; Examples include aluminum-based silane coupling agents such as acetalkoxyaluminum diisopropylate. These silane coupling agents (E) can be used alone or in combination of two or more. Among these, 3-(meth)acryloyloxypropyltrimethoxysilane is preferred due to its good compatibility with the acrylate compound (B). The amount of silane coupling agent (E) used in this embodiment is preferably in the range of 10 to 30 parts by mass per 100 parts by mass of zirconia, since the resulting active energy ray curable composition has excellent dispersion stability, low viscosity, high refractive index performance, and excellent bleed-out resistance to form a cured coating film.
[0074] [solvent] The active energy ray curable composition of this embodiment may contain 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 composition of this embodiment may, for example, include the solvent used in synthesizing each resin. Furthermore, the active energy ray curable composition of this embodiment may be prepared by mixing inorganic particles (A), a solvent, and an optional component to prepare an inorganic particle (A) dispersion, and then mixing it with a (meth)acrylate compound (B) and a photopolymerization initiator (C). The above-mentioned example of containing a solvent is just one example, and even if a solvent is included in the process of preparing the active energy ray curable composition of this embodiment, it is preferable to ultimately volatilize the solvent and keep the solvent content as low as possible. Therefore, when the active energy ray curable composition of this embodiment contains a solvent, the solvent content in the active energy ray curable composition is preferably 0 to 5% by mass, and more preferably 0 to 0.1% by mass.
[0075] [Viscosity of activated energy ray-curable compositions] The viscosity of the active energy ray curable composition of this embodiment at 25°C is preferably 6500 mPa·s or less, more preferably 3500 mPa·s or less, and even more preferably 1500 mPa·s or less. It is also preferable that it be 100 mPa·s or more. Within this range, it has good coating suitability.
[0076] [Method for preparing an active energy ray-curable composition] The method for preparing the active energy ray curable composition of this embodiment is not particularly limited. For example, one method involves obtaining a dispersion of inorganic particles (A), and then mixing the dispersion of inorganic particles (A), the monofunctional (meth)acrylate, the photoinitiator, and optionally the polyfunctional (meth)acrylate, various other additives. A method for producing the active energy ray curable composition of this embodiment preferably includes the steps of: preparing an inorganic particle (A) dispersion; and mixing the inorganic particle (A) dispersion, the monofunctional (meth)acrylate, a photoinitiator, and optionally a polyfunctional (meth)acrylate and various other additives. The mixing method is not particularly limited, but one example is the use of a media-type wet disperser.
[0077] Furthermore, in the step of preparing the inorganic particle (A) dispersion, at least a portion of the monofunctional (meth)acrylate, or, if necessary, at least a portion of the polyfunctional (meth)acrylate, may be added.
[0078] <Inorganic particle (A) dispersion> The inorganic particle (A) dispersion according to this embodiment preferably comprises, for example, the inorganic particle (A), the solvent, and the dispersant (D) as an additive. The inorganic particle (A) dispersion according to this embodiment may further comprise at least a portion of the monofunctional (meth)acrylate, or optionally at least a portion of the polyfunctional (meth)acrylate. The dispersant (D) is preferably in the range of 50 to 300 mgKOH / g. Generally, with the dispersant (D), inorganic nanoparticles tend to aggregate in the system due to interactions between the inorganic particles (A) and other resin components contained in the active energy ray curable composition of this embodiment, which can lead to a decrease in the storage stability of the active energy ray curable composition and a decrease in the transparency of the cured coating film. By using a dispersant (D) with an acid value in the range of 50 to 300 mgKOH / g, a curable composition with excellent long-term 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 particle (A) dispersion according to this embodiment more preferably further contains the silane coupling agent (E) as an additive. Functional groups can be introduced to the surface of the inorganic particles (A) using the various silane coupling agents (E) described above.
[0079] The method for producing the inorganic particle (A) dispersion according to this embodiment is not particularly limited, but examples include a method of producing it by dispersing raw materials containing the inorganic particles (A), the dispersant (D), and optionally the silane coupling agent (E) in a media-type wet disperser.
[0080] 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.).
[0081] The media used in the disperser is not particularly limited as long as it is a commonly known bead, but zirconia, alumina, silica, glass, silicon carbide, and silicon nitride are preferred. The average particle size of the media is preferably 50 to 500 μm, and media 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, so the increase in surface energy of the dispersed particles can be suppressed, and re-aggregation can be prevented.
[0082] 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.
[0083] 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.
[0084] In the manufacturing method using the media-type wet disperser, the order in which the raw materials are loaded into the disperser is not particularly limited, but by supplying the dispersant (D) last, a curable composition with excellent dispersion stability can be obtained using only a small amount of dispersant (D). More specifically, a method can be used in which the raw materials other than the dispersant (D) are loaded first, mixed or pre-dispersed, and then the dispersant (D) is loaded last to perform the main dispersion process.
[0085] 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.
[0086] Furthermore, the particle size (average particle size) of the inorganic particles (A) in the inorganic particle (A) dispersion is larger than the average primary particle size of the inorganic particles (A) that are the raw materials for the inorganic particle (A) dispersion, because some of the inorganic particles (A) are aggregated in the dispersion. Therefore, the average particle size of the inorganic particles (A) in the inorganic particle (A) dispersion is preferably 100 nm or less, more preferably in the range of 1 to 100 nm, and even more preferably in the range of 20 to 100 nm, since this results in a cured product with a high refractive index and excellent light transmittance. The above particle size was measured by dynamic light scattering.
[0087] [Properties of Active Energy Ray Curable Compositions] The active energy ray curable composition of this embodiment has good self-healing properties and a high refractive index and low viscosity. Examples of the active energy ray curable composition of this embodiment include LUXYDIR® (manufactured by DIC Corporation).
[0088] (cured product) The cured product of this embodiment is a cured product of the active energy ray curable composition of this embodiment described above. The cured product of this embodiment can be used in a variety of applications, such as optical lenses, optical films (shaping optical films), anti-reflective materials, thin film sealing materials, optical adhesives, optical bonding agents, and diffusion microlenses. Furthermore, the shape of the cured product in this embodiment is not particularly limited and can be selected according to the application, such as a flat sheet with a smooth surface, a sheet with a fine uneven structure, or a sheet with a curved surface like a concave or convex lens. The cured product of this embodiment preferably has a refractive index (589 nm) of 1.62 or higher at 25°C (589 nm), more preferably 1.65 or higher, and even more preferably 1.66 or higher, from the viewpoint of enabling the thinning of optical lenses, reducing the refractive index difference with transparent electrodes 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 portion in LED encapsulants. Furthermore, there is no particular upper limit to the refractive index, and a higher value is preferable. If we had to specify an upper limit, from the viewpoint of balancing with viscosity, a value of 1.62 to 1.70 is preferable.
[0089] [Method for manufacturing hardened products] The method for producing the cured product of this embodiment is not particularly limited and includes, for example, a coating step of applying the active energy ray curable composition of this embodiment onto a substrate such as a transparent film; and a curing step of irradiating the film of the active energy ray curable 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 lot or wire bar, or various coating methods such as microgravure, gravure, die, curtain, lip, slot, or spin.
[0090] 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.
[0091] 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.
[0092] In addition to ultraviolet light, other active energy rays such as visible light and electron beams can also be used.
[0093] (Shaping optical film) The shaped optical film of this embodiment can be formed using the cured product of this embodiment described above. The shaped optical film of this embodiment may be, for example, the cured product of this embodiment formed on a substrate. The shaped optical film of this embodiment is, for example, obtained by shaping a fine pattern, such as a fine uneven structure, onto a cured product of the active energy ray curable composition of this embodiment. Depending on the application of the optical sheet, the fine pattern layer, such as the fine uneven structure, may have, for example, a fine uneven structure of 10 to 500 μm on its surface. Examples of the shaping optical film include polarizing films, phase difference films, anti-reflective films, brightness-enhancing films (prism sheets, microlens sheets, etc.), and light-diffusing films.
[0094] [Method for manufacturing shaped optical film] The method for manufacturing the shaped optical film of this embodiment is not particularly limited and includes, for example, the steps of: applying the active energy ray curable composition of this embodiment described above to the substrate; shaping the coating film using a mold with a desired fine pattern shape such as a fine uneven structure; and irradiating with active energy rays such as ultraviolet light to form a cured coating film.
[0095] As a method for manufacturing the shaped optical film of this embodiment, for example, as shown in Figure 2 of the Patent Document (Japanese Patent Application Publication No. 2009-37204), the above composition is placed in a mold with a desired fine pattern shape, such as a fine uneven structure, a transparent substrate layer is placed on top, the transparent substrate layer is pressed onto the composition using a laminator or the like, and the composition is cured with ultraviolet light or the like to form a fine pattern shape, such as a fine uneven structure. Then, by peeling or removing the mold with the fine pattern shape, a shaped optical film is obtained that has an optical function manifesting portion having the desired fine pattern shape on the transparent substrate layer.
[0096] (Optical sheet) The optical sheet of this embodiment can be formed using the cured product of this embodiment described above. The optical sheet of this embodiment may include, for example, a substrate and the cured product according to this embodiment formed on the substrate. The optical sheet of this embodiment may have, for example, a fine pattern layer such as a fine uneven structure which is a cured product of the active energy ray curable composition of this embodiment, and a transparent substrate. Furthermore, the fine pattern layer such as the fine uneven structure may have, for example, a fine uneven structure of 10 to 500 μm on its surface, depending on the application of the optical sheet. Furthermore, the cured product of the active energy ray curable composition in the optical sheet of this embodiment does not have a fine uneven structure, but may have a smooth surface. The shape can be appropriately selected according to various applications. Examples of the optical sheets include polarizing films, phase difference films, anti-reflective films, brightness-enhancing films (prism sheets, microlens sheets, etc.), light-diffusing films, and hard-coat films.
[0097] [Base material] Examples of substrates used in this embodiment include polyethylene terephthalate (PET), triacetyl cellulose (TAC), cycloolefin polymer (COP), cycloolefin copolymer (COC), polycarbonate, vinyl chloride, polymethacrylimide, polyimide, polyester, acrylic substrates mainly composed of polymethyl methacrylate (PMMA), 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, the 125 μm polyethylene terephthalate (PET) substrate (product name: A4300, manufactured by Toyobo Co., Ltd.) used in the example.
[0098] If the substrate is transparent, a transparent substrate used in conventionally known optical sheets such as prism sheets can be used. For example, the transparent substrate described in Patent Document 2 can be used. The transparent substrate may be a resin substrate or a glass substrate. Preferred transparent resin substrates include acrylic resin, polycarbonate resin, vinyl chloride resin, polymethacrylimide resin, polyimide resin, polyester resin, cycloolefin polymer (COP) resin and cycloolefin copolymer (COC) resin, and cellulose triacetate (TAC) resin.
[0099] The transparent substrate may be in the form of a long, rectangular piece, or it may be in the form of a single sheet of a predetermined size. The thickness of the transparent substrate is usually preferably 50 to 500 μm, but is not limited thereto. For use as the front surface of a display, the light transmittance of the transparent substrate is ideally 100%, and preferably 85% or higher. The transparent substrate may, if necessary, have its surface treated with a conventionally known matte finish (formation of light-diffusing micro-irregularities), an antistatic treatment, or an anti-reflective treatment. Alternatively, a matte finish, antistatic treatment, or anti-reflective treatment may be applied between the transparent resin and the substrate, or these may be used in any combination.
[0100] [Manufacturing method for optical sheets] The method for manufacturing the optical sheet of this embodiment is not particularly limited and may include, for example, the steps of applying the active energy ray curable composition of this embodiment described above to the substrate and irradiating it with active energy rays such as ultraviolet light to form a cured coating film. The method for manufacturing the laminate of this embodiment may include, for example, the steps of applying the active energy ray curable composition of this embodiment described above to a triacetylcellulose substrate film (TAC substrate film) with a thickness of 40 to 100 μm and irradiating it with 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.
[0101] As a method for manufacturing the optical sheet of this embodiment, for example, as shown in Figure 2 of the Patent Document (Japanese Patent Application Publication No. 2009-37204), the above composition is placed in a mold with a desired fine pattern shape, such as a fine uneven structure, a transparent substrate layer is placed on top, the transparent substrate layer is pressed onto the composition using a laminator or the like, and the composition is cured with ultraviolet light or the like to form a fine pattern shape, such as a fine uneven structure. Then, by peeling or removing the mold with the fine pattern shape, an optical sheet is obtained that has an optical function manifesting part having the desired fine pattern shape on the transparent substrate layer.
[0102] <Prism Sheet> A prism sheet is a specific example of the optical sheet of this embodiment. The prism sheet comprises, for example, a finely textured layer which is a cured product of the active energy ray curable composition of this embodiment, and a transparent substrate. The finely textured layer has a finely textured structure with a period of 10 to 100 μm on its surface. The thickness of the finely textured layer is, for example, 5 μm to 100 μm.
[0103] Typically, when the composition contains a large amount of monofunctional (meth)acrylate, the branching of the polymer structure after curing tends to decrease, resulting in poor self-healing properties of the cured product. Focusing on this tendency, the present invention was able to improve self-healing properties by setting the mass ratio of the monofunctional (meth)acrylate to inorganic particles (A) [(A) / (B)] to be in the range of 0.5 to 3. More specifically, when [(A) / (B)] is in the range of 0.5 to 3, inorganic particles (A) tend to be present on the surface when the composition is coated onto a substrate (i.e., near the interface between the composition and the mold), which is thought to reduce the adhesion of the cured product of the composition to the mold. Furthermore, the inclusion of a silane coupling agent and a phosphate ester dispersant containing a (meth)acryloyl group in the composition further improved the self-healing properties of the cured product. This is thought to be because the inorganic particles (A) become compatible with components other than (A) in the composition via the silane coupling agent and the phosphate ester dispersant, thereby increasing the strength of the cured product and making it less likely for the cured product to remain on the mold when it is separated from the mold. Furthermore, in this invention, substrate adhesion was particularly improved when orthophenylphenol (EO) acrylate, biphenylmethyl acrylate, and (1-naphthyl)methyl acrylate were used as monofunctional (meth)acrylates. These compounds are monomers with relatively high glass transition temperatures, and it is thought that this also improves the hardness of the coating film of the composition. It is possible that this improvement in hardness, along with several other factors, combined to improve substrate adhesion. In addition, good adhesion to the substrate was also observed when phenoxyethyl acrylate was used as the monofunctional (meth)acrylate. This is thought to be because phenoxyethyl acrylate contains a highly polar ethylene oxide structure within its molecule, which increases its interaction with the substrate. As described above, a configuration that yields a more effective result and the mechanism by which these effects are thought to be achieved have been explained. However, the present invention is not limited to these configurations, and the problems of the present invention can also be solved with compositions that do not contain a silane coupling agent and a phosphate ester dispersant, or with compositions that do not contain a specific compound as a monofunctional (meth)acrylate. [Examples]
[0104] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. (raw materials) "Zirconia (A)": UEP-100 (manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd.) "Dispersant (1)" (phosphate ester compound): Compound represented by the following structural formula (1)
[0105] [ka]
[0106] (In the formula, R 1 is a methyl group, R 2 (where is an ethylene chain with 2 carbon atoms, x is 5, y is 2 (average value), and n is an integer between 1 and 3)
[0107] "Silane coupling agent (E)": KBM-503 (manufactured by Shin-Etsu Chemical Co., Ltd., 3-(trimethoxysilyl)propyl methacrylate), 3-methacryloxypropyltrimethoxysilane
[0108] "Monofunctional (meth)acrylate compound (B1)": Phenylbenzyl acrylate: MIRAMER M1192 (manufactured by MIWON SPECIALTY CHEMICAL CO., LTD.) Phenoxybenzyl acrylate: KOMERATE A008 (manufactured by Green Chemical Co., Ltd.) OPPEA:KOMERATE A011 (manufactured by Green Chemical Co., Ltd.) Benzyl acrylate: MIRAMER M1182 (manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD.) Phenoxyethyl acrylate: Photomer 4035 (manufactured by IGM Resins Inc.), product name: KOMERATE A014 (manufactured by Green Chemical Co., Ltd.) PH(EO)2A: MIRAMER M142 (manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD.) PH(EO)4A: MIRAMER M144 (manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD.)
[0109] "Polyfunctional (meth)acrylate compounds" A mixture of PETA and PETTA: Arronix M-305 (manufactured by Toagosei Co., Ltd.) PETTA, Product name: KOMERATE M004 (Manufactured by Green Chemical Co., Ltd.) TMP(EO)3TA: MIRAMER M3130 (manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD.)
[0110] "Photopolymerization Initiator (C)": 1-Hydroxycyclohexylphenyl ketone: Runtecure 1104 (manufactured by Runtec Chemical Co., Ltd.) 2,4,6-Trimethylbenzoyldiphenylphosphine oxide: Runtecure 1108 (manufactured by Runtec Chemical Co., Ltd.)
[0111] <Refractive index of liquid> The active energy ray curable composition was directly applied to the prism of an Abbe refractometer, and measurements were taken at 25°C. Measurement wavelength: 589 nm.
[0112] <Viscosity> Viscosity was evaluated using an E-type rotational viscometer (TVE-25H, manufactured by Toki Sangyo Co., Ltd.) to measure the viscosity at a temperature of 25°C.
[0113] <Self-healing property> An active energy ray-curable resin composition is filled between a mold with a linear arrangement of bumps and dips of unit prism (pitch 50 μm, height 25 μm) and a transparent, easily adhesive treated PET film (product name: A4300, thickness: 125 μm, manufactured by Toyobo Co., Ltd.) as a transparent substrate, and then heated with an ultra-high-pressure mercury lamp at 400 mJ / cm². 2 The PET film was cured by irradiating it with ultraviolet light from the side, and then the PET film was peeled off the mold together with the active energy ray curable resin layer to create a cured PET film with the desired shape transferred onto it. A PET film cured with a specific shape was attached to a movable platen manufactured by Imoto Seisakusho, with the top of the cured film facing the load area. On the load area side, a 1 cm diameter holder with a diffusion film attached was used as an abrasion element, and the base layer of the diffusion film was positioned to rub against the top of the cured film. The evaluation was conducted indoors at a temperature of 23°C and a humidity of 50%. A 300 g load was applied to the load area, and the abrasion resistance tester was operated. The movable platen was moved once in one direction (movement speed: 4 m / min, movement distance: 10 cm). After this, the degree of band-shaped scratches was visually evaluated, with A to B being considered acceptable, and the following judgments were made. A: Wounds heal instantly. B: Wounds heal within 10 seconds C: Wounds heal within 30 seconds D: The wound has not healed after 30 seconds.
[0114] <Martens hardness (HM) and elastic deformation power (nIT)> An active energy ray-curable resin composition was filled between two glass plates using a 125 μm thick PET film as a spacer, and then heated with a super-high-pressure mercury lamp at 400 mJ / cm². 2 The material was cured by irradiating it with ultraviolet light, and then the glass plate on the opposite side of the irradiated surface was peeled off to create a flat, 125 μm thick cured film on the glass plate. The Martens hardness (HM) and elastic deformation power (nIT) of the prepared flat films were measured using a microhardness tester (product name HM2000) manufactured by Fischer Instruments Co., Ltd. in accordance with ISO 14577-1. The test conditions are as follows: Indenter: Vickers indenter F:30 mN / 5s C:5.0s R: 0.1 mN / 5s C2:10.0s
[0115] The Martens hardness (HM) was calculated using the following formula (for a Vickers indenter). Martens hardness (unit: N / mm) 2 ) = Test load F / 26.43 × {(Indentation depth h2 after holding maximum test force)^2}
[0116] The elastic deformation power (nIT) was calculated using the following formula. Elastic deformation power (unit: %) = W elast / (W elast +W plast ) × 100
[0117] Figure 1 illustrates the method for measuring elastic deformation power. In the above formulas for Martens hardness and elastic deformation power, F is the test load (test force), h² is the indentation depth after holding the maximum test force, and W is the work of elastic deformation. elast Work of plastic deformation W elast The relationship is shown in Figure 1.
[0118] The overall assessment was made based on the values of liquid refractive index, Martens hardness, elastic deformation power, viscosity, and self-healing properties, as follows: 5 Physical properties passed:〇 3~4 physical properties passed:△ 0~2 Physical properties passed: ×
[0119] The acceptable values for each physical property were as follows: Liquid refractive index: 1.59 or higher Martens hardness: 20 N / mm 2 below Elastic deformation power: 40% or more Viscosity: 100mPa·s or more and 1000mPa·s or less Self-healing property: C or higher
[0120] If the liquid refractive index is within the acceptable range, it will have sufficient optical performance (in the case of prism sheets, improved brightness). If the Martens hardness is within the acceptable range, it will be less likely to scratch other materials when in contact with them. If the elastic deformation power and self-healing properties are within the acceptable range, it will be less likely to chip or scratch other materials when in contact with them. If the viscosity is within the acceptable range, it will have coating suitability.
[0121] (Example 1) As zirconia, UEP-100, 52.14 parts by mass, As a phosphate ester, 9.52 parts by mass of a phosphate ester represented by the above structural formula (1) (dispersant (1)) and As a silane coupling agent (1), 10.26 parts by mass of KBM-503 and 112.10 parts by mass of methyl ethyl ketone (hereinafter abbreviated as "MEK"), The mixture was stirred in a dispersion stirrer for 30 minutes to achieve coarse dispersion. Next, the resulting mixture was dispersed using a media-type wet disperser (Star Mill LMZ-015, manufactured by Ashizawa Fine Tech Co., Ltd.) with zirconia beads having a particle size of 100 μm. The dispersion process was carried out with a residence time of 100 minutes while checking the particle size during the process to obtain an inorganic particle dispersion. This inorganic particle dispersion, Photomer 4035, 10.39 parts by mass, KOMERATE A008, 7.80 parts by mass, KOMERATE A014, 10.39 parts by mass, The volatile components were removed under reduced pressure while heating in an evaporator. Furthermore, As photopolymerization initiators, 1.00 parts by mass of Runtecure 1104 and 0.50 parts by mass of Omnirad 819 were added to prepare the active energy ray curable composition P1 (composition P1) of this embodiment. The liquid refractive index and viscosity of composition P1 were evaluated using the evaluation method described above. In addition, the Martens hardness (HM), elastic deformation power (nIT), and self-healing properties of the cured product of composition P1 were evaluated. The results are shown in Tables 1 to 5.
[0122] (Examples 2-17, Comparative Examples 1-29) Each example prepared compositions P2-P17 and cP1-cP29 for Examples 2-17 and Comparative Examples 1-29, respectively, using the same method as in Example 1, except that the components and composition ratios shown in Tables 1-5 were used. The amount of MEK used was 2.15 times the amount of inorganic particles shown in Tables 1-5, as in Example 1. The liquid refractive index, film refractive index, and viscosity of each composition were evaluated as in Example 1. In addition, the Martens hardness (HM), elastic deformation power (nIT), and self-healing properties of the cured products of each composition were evaluated. The results are shown in Tables 1-5.
[0123] [Table 1]
[0124] [Table 2]
[0125] [Table 3]
[0126] [Table 4]
[0127] [Table 5]
[0128] In Tables 1-5, the meaning of each entry is as follows: UEP-100: Zirconia, manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd. Dispersant (1): Phosphate ester represented by the following structural formula (1)
[0129] [ka]
[0130] KBM-503: 3-(trimethoxysilyl)propyl methacrylate, manufactured by Shin-Etsu Chemical Co., Ltd. KOMERATE A011: Orthophenylphenol (EO) acrylate, manufactured by Green Chemical Co., Ltd. Photomer 4035: Phenoxyethyl acrylate, manufactured by IGM Resins Inc. MIRAMER M1182: Benzyl acrylate, manufactured by MIWON SPECIALTY CHEMICAL CO., LTD. MIRAMER M142: Phenol-EO modified (n≒2) acrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. MIRAMER M144: Phenol-EO modified (n≒4) acrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. MIRAMER M2100: Bisphenol A EO-modified (n≒10) diacrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. MIRAMER M3130: Trimethylolpropane EO-modified (n≒3) triacrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. MIRAMER M3160: Trimethylolpropane EO-modified (n≒6) triacrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. Aronix M-305 is a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (containing approximately 60% triacrylate), manufactured by Toagosei Co., Ltd. MIRAMER M1192: Biphenyl methyl acrylate, manufactured by MIWON SPECIALTY CHEMICAL CO., LTD.
[0131] KOMERATE A008: Phenoxybenzyl acrylate, manufactured by Green Chemical Co., Ltd. KOMERATE A005: Tetrahydrofluoracrylate, manufactured by Green Chemical Co., Ltd. KOMERATE A014: Phenoxyethyl acrylate, manufactured by Green Chemical Co., Ltd. KOMERATE D064: Bisphenol fluorene EO-modified (n≒6) diacrylate, manufactured by Green Chemical Co., Ltd. KOMERATE D204: Bisphenol fluorene EO-modified (n≒20) diacrylate, manufactured by Green Chemical Co., Ltd. KOMERATE M004: Pentaerythritol tetraacrylate, manufactured by Green Chemical Co., Ltd. KOMERATE M006: Dipentaerythritol hexaacrylate, manufactured by Green Chemical Co., Ltd. KOMERATE M136: Dipentaerythritol EO-modified (n≒13) hexaacrylate, manufactured by Green Chemical Co., Ltd. KOMERATE M246: Dipentaerythritol EO-modified (n≒24) hexaacrylate, manufactured by Green Chemical Co., Ltd.
[0132] MIRAMER M202: 1,6-hexanediol EO-modified (n≒2) diacrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. MIRAMER M2200 Bisphenol A EO-modified (n≒20) diacrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. MIRAMER M244: Bisphenol A EO-modified (n≒6) diacrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD. MIRAMER M180: Stearyl acrylate, manufactured by MIWON SPECIALTY CHEMICAL CO., LTD. MIRAMER M262: Tricyclodecanedimethanol diacrylate, manufactured by MIWON SPECIALTY CHEMICAL CO., LTD. MIRAMER M164: Nonylphenol EO-modified (n≒4) acrylate, manufactured by MIWON SPECIALTY CHEMICAL CO.,LTD.
[0133] ACMO Acryloyl Morpholin, KJ Chemicals Co., Ltd. Arronix M-309: Trimethylolpropane triacrylate, manufactured by Toagosei Co., Ltd. Praxel FA2D, polycaprolactone-modified (n≒2) hydroxyethyl acrylate, manufactured by Daicel Chemical Industries, Ltd. Praxel FA5: Polycaprolactone-modified (n≒5) hydroxyethyl acrylate, manufactured by Daicel Chemical Industries, Ltd. Praxel FA1DDM: Polycaprolactone-modified (n≒1) hydroxyethyl acrylate, manufactured by Daicel Chemical Industries, Ltd. Runtecure 1104: Dipentaerythritol EO-modified (n≒13) hexaacrylate, (manufactured by Runtec Chemical Co., Ltd.) Omnirad 819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, manufactured by IGM Resins Inc.
[0134] MaxEstateIndex: The value of the largest Estate in the molecule. SaasC: Total Estate of Aromatic Rings SdCH2: Sum of the states of the unsaturated double bond SssCH2: Sum of EState values for the "-CH2-" structure HM_N / mm 2 : Martens hardness (= test load F / 26.43 × {(indentation depth h2 after holding maximum test force)^2}) (Unit: N / mm 2 ) *In the case of a Vickers indenter nIT_%: Elastic deformation power (=W) elast / (W elast +W plast ) × 100) (Unit: %)
[0135] (Consideration) As shown in Tables 1-5, by setting the inorganic particle content, parameter SdCH2, parameter SaasC, and parameter MaxEStateIndex within predetermined ranges, it was possible to achieve both good self-healing properties, low viscosity, and high refractive index. Furthermore, by setting these parameters within particularly favorable ranges, an even better balance of physical properties was achieved (Examples 1 and 2). Focusing on the parameter MaxEStateIndex, when other parameters are equivalent, a larger MaxEStateIndex resulted in lower viscosity. This is thought to be because structures with high polarizability have better compatibility with inorganic particles. When focusing on the inorganic particle content, it was found that, given equivalent other parameters, viscosity increased with increasing inorganic particle content. This is because, as particle concentration increases, the distance between particles decreases, and their interactions contribute to viscosity. A large parameter SdCH2 leads to more crosslinking sites after hardening, resulting in increased HM (Martens hardness), decreased nIT (elastic deformation power), and reduced flexibility and self-healing properties. A large parameter SssCH2 is thought to result in more -CH2- bonds and greater molecular mobility. Therefore, nIT (elastic deformation power) increases, improving flexibility and self-healing properties. A larger parameter SaasC results in a higher refractive index, but also increases the HM (Martens hardness), decreases the nIT (elastic deformation power), and reduces flexibility and self-healing properties. This is because it possesses a rigid aromatic ring structure. By using four molecular descriptors plus inorganic particle concentration as explanatory variables, desired physical properties can be predicted with high accuracy, and the composition can be optimized. In other words, the combination of the four molecular descriptors is suitable for representing the physical properties of a composition. [Explanation of symbols]
[0136] F Test Power h depth of indentation W elast Work done by elastic deformation W plast Work of plastic deformation h1 Depth of indentation at the arrival of maximum test force H2: Depth of indentation after holding maximum test force. h max Maximum indentation depth
Claims
1. An active energy ray curable composition containing inorganic particles (A), a (meth)acrylate compound (B), and a photopolymerization initiator (C), The content of the inorganic particles (A) in the active energy ray curable composition is 30% by mass or more and 60% by mass or less. The value of the parameter SdCH2 generated from the composition of the aforementioned active energy ray curable composition is 3.00 to 10.
00. The value of the parameter SaasC generated from the composition of the aforementioned active energy ray curable composition is between 0.00 and 6.
00. The value of the parameter MaxESTateIndex generated from the composition of the aforementioned active energy ray curable composition is between 14.00 and 28.
00. An active energy ray curable composition wherein the value of the parameter SssCH2 generated from the composition of the active energy ray curable composition is 0.00 to 5.
00. The parameter SdCH2 is a value calculated using the SdCH2 (compound) of each component contained in the active energy ray curable composition, and the SdCH2 (compound) is the parameter obtained by the following formula (1). EState value of the SdCH2 (compound) = Σ "=CH2" structure (1) The parameter SaasC is a value calculated using the SaasC(compound) of each component contained in the active energy ray curable composition, and the SaasC(compound) is the parameter obtained by the following formula (2). SaasC = Σ "aCa-" structure ESTate value (2) The parameter MaxEstateIndex is a value calculated using the MaxEstateIndex(compound) of each component contained in the active energy ray curable composition, and the MaxEstateIndex(compound) is a parameter obtained by the following formula (3). MaxEstateIndex = The largest Estate value in the numerator (3) The parameter SssCH2 is a value calculated using the SssCH2 (compound) of each component contained in the active energy ray curable composition, and the SssCH2 (compound) is the parameter obtained by the following formula (4). SssCH2 = Σ"-CH2-" structure ESTate value (4)
2. The activated energy ray curable composition according to claim 1, wherein the inorganic particle (A) is zirconia.
3. The active energy ray curable composition according to claim 1 or 2, wherein the particle size of the inorganic particles (A) measured by dynamic light scattering is 1 to 100 nm.
4. The active energy ray curable composition according to claim 1 or 2, wherein the (meth)acrylate compound (B) contains a biphenyl structure.
5. The active energy ray curable composition according to claim 1 or 2, wherein the (meth)acrylate compound (B) contains biphenylmethyl (meth)acrylate.
6. The active energy ray curable composition according to claim 1 or 2, wherein the active energy ray curable composition is for use in shaped optical films.
7. A cured product of the active energy ray curable composition according to claim 1 or 2.
8. A shaped optical film comprising the cured product described in claim 7.
9. An optical sheet comprising the cured product described in claim 7.