Active energy ray-curable composition

Abstract

To provide an active energy ray-curable composition which gives a cured product having a high refractive index and is excellent in light resistance and dispersion stability.SOLUTION: The active energy ray-curable composition contains an active energy ray-polymerizable compound (A), inorganic particles (B), a photopolymerization initiator (C), and a dispersing agent (D), wherein the inorganic particles (B) are BaTiO3 having a number-average particle size of 5 to 40nm, and the dispersing agent (D) is a surface active agent having at least one functional group selected from the group consisting of carboxyl groups, phosphoric acid groups, thiol groups, hydroxyl groups, and amino groups.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable composition. [Background technology]

[0002] In recent years, high refractive index particles have been widely studied as fillers for anti-reflection materials, lens materials, high dielectric materials, etc. High refractive index particles of several to several tens of nanometers in size are particularly popular due to their excellent transparency. Conventionally, particles of zirconia, titania, etc. have been used for UV-curable resins (Patent Document 1). However, with this technology, the refractive index and light resistance were insufficient, and dispersion stability was sometimes insufficient. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-6984 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an active energy ray-curable composition which gives a cured product having a high refractive index and is excellent in light resistance and dispersion stability.

[0005] The present inventors have conducted extensive research to solve these problems and have arrived at the present invention. That is, the present invention provides an active energy ray-curable composition containing an active energy ray-polymerizable compound (A), inorganic particles (B), a photopolymerization initiator (C), and a dispersant (D), wherein the inorganic particles (B) are BaTiO3 having a number average particle diameter of 5 to 40 nm, and the dispersant (D) is a surfactant having at least one functional group selected from the group consisting of a carboxyl group, a phosphate group, a thiol group, a hydroxyl group, and an amino group; and a cured product of the active energy ray-curable composition. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide an active energy ray-curable composition that gives a cured product having a high refractive index and is excellent in light resistance and dispersion stability. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention will be described in detail below.

[0008] <Active energy ray-curable composition> The active energy ray-curable composition of the present invention (hereinafter also referred to as "the curable composition of the present invention") is an active energy ray-curable composition containing an active energy ray-polymerizable compound (A), inorganic particles (B), a photopolymerization initiator (C), and a dispersant (D), wherein the inorganic particles (B) are BaTiO3 having a number average particle diameter of 5 to 40 nm, and the dispersant (D) is a surfactant having at least one functional group selected from the group consisting of a carboxyl group, a phosphate group, a thiol group, a hydroxyl group, and an amino group.

[0009] <Active energy ray polymerizable compound (A)> The active energy ray-polymerizable compound (A) will be explained below. The active energy ray-polymerizable compound (A) is not particularly limited as long as it is a compound that polymerizes when exposed to active energy rays. Examples of active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays, and electron beams. Note that ultraviolet rays refer to light rays with a wavelength of 200 nm to 410 nm. Specific examples of the active energy ray-polymerizable compound (A) include a monofunctional monomer (A1) and a polyfunctional monomer (A2). From the viewpoints of viscosity and curability, the photopolymerizable compound (A) preferably contains a monofunctional monomer (A1) and a polyfunctional monomer (A2). Preferred examples of the functional group that polymerizes when exposed to active energy rays include functional groups having an ethylenically unsaturated bond, such as a vinyl group, an allyl group, a propargyl group, a butenyl group, an ethynyl group, a phenylethynyl group, a maleimide group, a nadimide group, and a (meth)acryloyl group. From the viewpoint of curability, a vinyl group or a (meth)acryloyl group is more preferred. Furthermore, the monofunctional monomer (A1) is a compound having one functional group that undergoes a polymerization reaction when exposed to active energy rays, and the polyfunctional monomer (A2) is a compound having two or more functional groups that undergo a polymerization reaction when exposed to active energy rays. In this specification, "(meth)acrylate" means "acrylate and / or methacrylate," "(meth)acrylic" means "acrylic and / or methacrylic," and "(meth)acryloyl" means "acryloyl and / or methacryloyl."

[0010] Examples of the monofunctional monomer (A1) include monofunctional (meth)acrylates, monofunctional urethane (meth)acrylates, monofunctional (meth)acrylamides, and monofunctional N-vinyl compounds.

[0011] Examples of the monofunctional (meth)acrylate include mono(meth)acrylates having a chain aliphatic group having 4 to 22 carbon atoms {e.g., 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, 2-ethylhexyl(meth)acrylate, etc.}, glycidyl(meth)acrylate, hydroxyalkyl(meth)acrylate {e.g., 2-hydroxyethyl(meth)acrylate, acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.}, alkoxyalkyl (meth)acrylate {for example, 2-methoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, etc.}, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 4-nonylphenoxyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, alicyclic skeleton-containing mono(meth)acrylates [for example, (meth)acrylates containing an alicyclic skeleton having 6 to 12 carbon atoms {for example, cyclohexyl (meth)acrylate, cyclohexylmethyl (meth)acrylate, cyclohexylethyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, 2-acryloyloxyethyl hexahydrophthalate, etc.}], aromatic ring skeletons (meth)acrylates [for example, aromatic ring skeleton-containing mono(meth)acrylates having 6 to 55 carbon atoms {for example, phenyl(meth)acrylate, benzyl(meth)acrylate, phenoxyethyl(meth)acrylate, phenoxy 2-methylethyl(meth)acrylate, phenoxyethoxyethyl(meth)acrylate (phenoxydiethylene glycol(meth)acrylate), paracumylphenoxyethyl(meth)acrylate, 4-biphenylmethylacrylate, phenoxybenzyl(meth)acrylate (m-phenoxybenzyl acrylate),2-hydroxy-3-phenoxypropyl (meth)acrylate, phenylbenzyl (meth)acrylate, phenylphenoxyethyl acrylate (o-phenoxyphenylethyl acrylate), (naphthyl)methyl acrylate, 1,1-biphenyl-2-yl acrylate, dinaphthothiophene derivatives, and mono(meth)acrylate compounds containing a fluorene skeleton}], and other mono(meth)acrylate compounds.

[0012] Examples of the monofunctional urethane (meth)acrylate include a reaction product of a monofunctional (meth)acrylate (a) having a hydroxyl group and an organic monoisocyanate compound (b). Examples of the monofunctional (meth)acrylate (a) having a hydroxyl group include hydroxyalkyl (meth)acrylates (2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 1,4-cyclohexanedimethanol monoacrylate). The monofunctional (meth)acrylate (a) having a hydroxyl group may be used alone or in combination of two or more kinds. Examples of the organic monoisocyanate compound (b) include an aliphatic monoisocyanate compound (b1), an alicyclic monoisocyanate compound (b2), and an aromatic monoisocyanate compound (b3). The aliphatic monoisocyanate compound (b1) includes those having an alkyl group having 1 to 20 carbon atoms, such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, hexyl isocyanate, octyl isocyanate, lauryl isocyanate, tetradecyl isocyanate, hexadecyl isocyanate, and octadecyl isocyanate. The alicyclic monoisocyanate compound (b2) includes compounds having a hydrocarbon group with 5 to 13 carbon atoms and an alicyclic skeleton, such as cyclohexyl isocyanate. The aromatic monoisocyanate compound (b3) includes those having a hydrocarbon group with an aromatic ring and 6 to 12 carbon atoms, such as phenyl isocyanate and tolylene isocyanate. The organic monoisocyanate compound (b) may be used alone or in combination of two or more kinds.

[0013] Of these organic monoisocyanate compounds (b), from the viewpoint of flexibility and viscosity of the cured product, preferred are the aliphatic monoisocyanate compound (b1) and the alicyclic monoisocyanate compound (b2), more preferred are the aliphatic monoisocyanate compound (b1), next more preferred are aliphatic monoisocyanate compounds having an alkyl group having 1 to 6 carbon atoms, and particularly preferred are methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate and hexyl isocyanate.

[0014] The monofunctional urethane (meth)acrylate can be obtained by a known urethane reaction between a monofunctional (meth)acrylate (a) having a hydroxyl group and an organic monoisocyanate compound (b). Commercially available products may also be used, such as Viscoat #216 (2-[(butylamino)carbonyl]oxyethyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.), Etermer EM2080 (manufactured by Choko Materials Industry Co., Ltd.), and Genomer 1122 (manufactured by RAHN).

[0015] Examples of monofunctional (meth)acrylamides include (meth)acrylamide, N-alkoxy(meth)acrylamide, N-alkyl(meth)acrylamide, N-alkoxyalkyl(meth)acrylamide, N-hydroxyalkyl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, N-alkoxy-N-alkyl(meth)acrylamide, and cyclic amides having an N-(meth)acryloyl group (heterocyclic skeleton-containing N-(meth)acrylamide). N-alkoxy(meth)acrylamides include those having an alkoxy group having 1 to 6 carbon atoms, such as N-methoxy(meth)acrylamide, N-ethoxy(meth)acrylamide, N-propoxy(meth)acrylamide, and N-butoxy(meth)acrylamide. N-Alkyl(meth)acrylamides include those having an alkyl group having 1 to 6 carbon atoms, such as N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N-butyl(meth)acrylamide. N-alkoxyalkyl(meth)acrylamides include those having an alkoxyalkyl group having 1 to 6 carbon atoms, such as Nn-butoxymethylacrylamide. N-hydroxyalkyl(meth)acrylamides include those having a hydroxyalkyl group having 1 to 6 carbon atoms, such as N-hydroxyethyl(meth)acrylamide. N,N-dialkyl(meth)acrylamides include those having an alkyl group having 1 to 22 carbon atoms, and examples thereof include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N,N-diisobutyl(meth)acrylamide, N,N-di-tert-butyl(meth)acrylamide, N,N-diheptyl(meth)acrylamide, N,N-dioctyl(meth)acrylamide, N,N-di-tert-octyl(meth)acrylamide, N,N-didodecyl(meth)acrylamide, and N,N-dioctadecyl(meth)acrylamide. Examples of N-alkoxy-N-alkyl(meth)acrylamides include Nn-butoxy-N-methyl(meth)acrylamide, N-methyl-N-methoxy(meth)acrylamide, N-methyl-N-ethoxy(meth)acrylamide, N-methyl-N-propoxy(meth)acrylamide, N-ethyl-N-methoxy(meth)acrylamide, N-ethyl-N-ethoxy(meth)acrylamide, N-ethyl-N-butoxy(meth)acrylamide, N-propyl-N-methoxy(meth)acrylamide, N-propyl-N-ethoxy(meth)acrylamide, N-butyl-N-methoxy(meth)acrylamide, and N-butyl-N-ethoxy(meth)acrylamide. Examples of cyclic amides having an N-(meth)acryloyl group (also referred to as heterocyclic skeleton-containing mono N-(meth)acrylamides) include N-(meth)acryloylmorpholine, N-(meth)acryloylthiomorpholine, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, and N-(meth)acryloylpiperidine.

[0016] Examples of monofunctional N-vinyl compounds include N-vinylcaprolactam, N-vinylformamide, N-vinylimidazole, N-vinylacetamide, and N-vinyl compounds containing a heterocyclic skeleton (e.g., N-vinyl-2-pyrrolidone, 5-methyl-3-vinyl-2-oxazolidinone, N-vinylcarbazole, and N-vinylphthalimide).

[0017] Among the monofunctional monomers (A1), from the viewpoints of curability, refractive index, and light resistance, monofunctional (meth)acrylates and monofunctional (meth)acrylamides are preferred, and more preferred is at least one monomer selected from the group consisting of alicyclic skeleton-containing mono(meth)acrylates, aromatic ring skeleton-containing mono(meth)acrylates, and heterocyclic skeleton-containing mono-N-(meth)acrylamides. Specifically, the alicyclic skeleton-containing mono(meth)acrylate is preferably isobornyl acrylate, and the aromatic ring skeleton-containing mono(meth)acrylate is preferably phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, o-phenoxyphenylethyl acrylate, m-phenoxybenzyl acrylate, (naphthyl)methyl acrylate, benzyl acrylate, 4-biphenylmethyl acrylate, and dinaphthothiophene derivatives, and the heterocyclic skeleton-containing mono(meth)acrylamides is preferably N-(meth)acryloylmorpholine, etc. Particularly preferred are aromatic ring skeleton-containing mono(meth)acrylates, and specific examples thereof include phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, o-phenoxyphenylethyl acrylate, m-phenoxybenzyl acrylate, (naphthyl)methyl acrylate, benzyl acrylate, 4-biphenylmethyl acrylate, and dinaphthothiophene derivatives.

[0018] Examples of the polyfunctional monomer (A2) include polyfunctional (meth)acrylate compounds, polyfunctional vinyl ether compounds, polyfunctional urethane (meth)acrylate compounds, and polyfunctional vinyl sulfide compounds.

[0019] Examples of polyfunctional (meth)acrylate compounds include difunctional (meth)acrylates, trifunctional (meth)acrylates, tetrafunctional (meth)acrylates, pentafunctional (meth)acrylates, and hexafunctional or higher (meth)acrylates. Examples of bifunctional (meth)acrylates include di(meth)acrylates containing an aromatic ring skeleton {for example, di(meth)acrylates of alkylene oxide (hereinafter, alkylene oxide may be abbreviated as "AO") adducts of dihydric phenol compounds [monocyclic phenols (catechol, resorcinol, hydroquinone, etc.), condensed polycyclic phenols (dihydroxynaphthalene, etc.), bisphenol compounds (bisphenol A, bisphenol F, bisphenol S, etc.)] (for example, ethoxylated bisphenol A diacrylate, propoxylated bisphenol A diacrylate, etc.), acrylic-modified bisphenoxyethanol fluorene, fluorene diacrylate, 4,4'-bisacryloxypropyl acrylate, 4,4'-bis(4-methyl-2-propanol), ... dimethylbiphenyl, bis(4-(meth)acryloylthiophenyl)sulfide, binaphthol derivatives, etc.}, polyalkylene glycol di(meth)acrylates (dipropylene glycol diacrylate, etc.), alicyclic skeleton-containing di(meth)acrylates {for example, dimethylol-tricyclodecane di(meth)acrylate, etc.}, monomers containing a heterocyclic skeleton (dinaphthothiophene derivatives (for example, dinaphthothiophene diacrylate), isocyanuric acid derivatives (for example, isocyanuric acid EO-modified diacrylate), etc.), neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate. Specific examples of the di(meth)acrylate of an AO adduct of a dihydric phenol compound include a di(meth)acrylate of an adduct of 4 moles of ethylene oxide (hereinafter, ethylene oxide may be abbreviated as "EO") to resorcinol, a di(meth)acrylate of an adduct of 4 moles of propylene oxide (hereinafter, propylene oxide may be abbreviated as "PO") to dihydroxynaphthalene, a di(meth)acrylate of an adduct of bisphenol A with 4 moles of EO, a di(meth)acrylate of an adduct of bisphenol A with 10 moles of EO, and a di(meth)acrylate of an adduct of bisphenol A with 20 moles of EO.

[0020] Examples of trifunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate, tri(meth)acrylates of AO adducts of trimethylolpropane (e.g., 6-mol EO adduct, 9-mol EO adduct, 15-mol EO adduct, 20-mol EO adduct, and 9-mol PO adduct of trimethylolpropane), pentaerythritol tri(meth)acrylate, tri(meth)acrylates of AO adducts of pentaerythritol (e.g., 6-mol EO adduct of pentaerythritol), and tri(meth)acrylates of AO adducts of glycerin (e.g., 6-mol EO adduct and 3-mol PO adduct of glycerin).

[0021] Examples of tetrafunctional (meth)acrylates include pentaerythritol tetra(meth)acrylate, tetra(meth)acrylates of AO adducts of pentaerythritol (e.g., 2-mol EO adduct, 4-mol EO adduct, 10-mol EO adduct, 15-mol EO adduct and 35-mol EO adduct of pentaerythritol), and tetra(meth)acrylates of AO adducts of ditrimethylolpropane (e.g., 10-mol EO adduct of ditrimethylolpropane).

[0022] Examples of the pentafunctional (meth)acrylate include dipentaerythritol penta(meth)acrylate and penta(meth)acrylates of AO adducts of dipentaerythritol (dipentaerythritol adducts of 2 moles of EO, 4 moles of EO, 10 moles of EO, and 15 moles of EO, etc.).

[0023] Examples of the hexa- or higher functional (meth)acrylate include dipentaerythritol hexa(meth)acrylate, hexa(meth)acrylate of an AO adduct of dipentaerythritol (e.g., an EO 2-mol adduct, an EO 4-mol adduct, an EO 10-mol adduct, and an EO 15-mol adduct of dipentaerythritol), and hexa(meth)acrylate of a lactone (e.g., γ-butyrolactone, γ-valerolactone, and ε-caprolactone) adduct of dipentaerythritol (e.g., an ε-caprolactone 3-mol adduct, an ε-caprolactone 6-mol adduct, and an ε-caprolactone 12-mol adduct of dipentaerythritol).

[0024] Examples of polyfunctional vinyl ether compounds include difunctional vinyl ether compounds and trifunctional or higher vinyl ether compounds. Examples of the difunctional vinyl ether compound include diethylene glycol divinyl ether and cyclohexanedimethanol divinyl ether.

[0025] Examples of polyfunctional urethane (meth)acrylate compounds include difunctional urethane (meth)acrylates and trifunctional or higher functional urethane (meth)acrylates. The polyfunctional urethane (meth)acrylate may be commercially available, such as Ebecryl 230, Ebecryl 8807, Ebecryl 9270, Ebecryl 8800, Ebecryl 4513, Ebecryl 680, Ebecryl 5129, KRM 8296, and KRM 8904 (all manufactured by Daicel-Allnex Co., Ltd.).

[0026] Examples of polyfunctional vinyl sulfide compounds include difunctional vinyl sulfide compounds and trifunctional or higher vinyl sulfide compounds. Examples of the bifunctional vinyl sulfide compound include 1,6-bisvinylthionaphthalene and 1,1'-thiobis(4-ethenylthiobenzene).

[0027] Among the above polyfunctional monomers (A2), polyfunctional (meth)acrylate compounds and polyfunctional vinyl sulfide compounds are preferred from the viewpoints of curability, refractive index, and light resistance, and bifunctional (meth)acrylates and bifunctional vinyl sulfide compounds are more preferred.

[0028] The weight ratio of the monofunctional monomer (A1) to the polyfunctional monomer (A2) [(A1) / (A2)] is preferably 0.1 to 9, more preferably 0.2 to 9, from the viewpoint of adhesion.

[0029] From the viewpoint of the refractive index of the cured product, the monomer constituting the active energy ray-polymerizable compound (A) preferably contains a monomer having at least one aromatic ring, and more preferably contains a monomer having two or more aromatic rings.

[0030] From the viewpoint of the refractive index and light resistance of the cured product, the active energy ray-polymerizable compound (A) preferably has a total content of alicyclic skeleton-containing mono(meth)acrylate, aromatic ring skeleton-containing mono(meth)acrylate, heterocyclic ring skeleton-containing mono-N-(meth)acrylamide, aromatic ring skeleton-containing di(meth)acrylate, heterocyclic ring skeleton-containing di(meth)acrylate, and alicyclic skeleton-containing di(meth)acrylate of 1 to 100% by weight, more preferably 20 to 100% by weight, based on the weight of the active energy ray-polymerizable compound (A).

[0031] The refractive index of the cured product of the active energy ray-polymerizable compound (A) is preferably 1.50 or more, more preferably 1.53 or more, from the viewpoint of thinning. The refractive index can be controlled by adjusting the amount of molecules containing atoms with different atomic refractions. The refractive index of the cured product of the active energy ray-polymerizable compound (A) can be measured by the following method. The active energy ray-polymerizable compound (A) mixed and dissolved with a photopolymerization initiator was sandwiched between two PET films [trade name: Lumirror S, manufactured by Toray Industries, Inc.] so that the active energy ray-polymerizable compound (A) had a thickness of about 5 μm, and was then irradiated with 1000 mJ / cm using an ultraviolet ray irradiation device [trade name: VPS / I600, manufactured by Fusion UV Systems, Inc.]. 2 After obtaining a cured product for refractive index evaluation by irradiating it with ultraviolet light, the refractive index at a wavelength of 589 nm (D line) is measured using an Abbe refractometer (DR-M2: manufactured by Atago Co., Ltd.). The refractive index of the active energy ray-polymerizable compound (A) is the refractive index of a cured product prepared without mixing with the inorganic particles (B), the photopolymerization initiator (C), and other components, and is measured based only on the composition of the active energy ray-polymerizable compound (A) constituting the active energy ray-curable composition.

[0032] From the viewpoint of imprinting properties, the viscosity of the active energy ray-polymerizable compound (A) at 25°C is preferably 300 mPa·s or less, more preferably 1 to 200 mPa·s, and particularly preferably 50 to 150 mPa·s. The viscosity of the active energy ray-polymerizable compound (A) at 25°C can be adjusted by the types and constituent ratios of the monomers that constitute the active energy ray-polymerizable compound (A). The viscosity of the active energy ray-polymerizable compound (A) at 25° C. was measured as follows.

[0033] <Viscosity measurement method> The mixture of active energy ray-polymerizable compound (A) is kept at 25°C for 30 minutes, and the viscosity (mPa s) is measured under the following conditions using an E-type viscosity measuring device [Toki Sangyo Co., Ltd. "VISCOMETER TV-25L"]. [Measurement conditions] Cone rotor: Standard cone rotor (1°34' x R24) Measurement temperature: 25℃ Measurement range: M Rotation speed: 50 rpm

[0034] <Inorganic particles (B)> The inorganic particles (B) will be explained below. The inorganic particles (B) are not particularly limited as long as they are BaTiO3 (barium titanate) with a number-average particle diameter of 5 to 40 nm. A number-average particle diameter of 5 to 40 nm provides excellent dispersion stability and a cured product with high light transmittance and refractive index. In the present invention, the number-average particle diameter of the inorganic particles (B) is the average primary particle diameter measured from approximately 300 particles in a photograph (25k) observed with a transmission electron microscope (JEOL Ltd., JEM-F200). Here, the average primary particle diameter is the particle diameter calculated by averaging the diameter of a circle (circle-equivalent diameter) with the same area as the area determined for each particle from the photograph.

[0035] The shape of the inorganic particles (B) is not particularly limited, and may be, for example, spherical, hollow, porous, rod-like, plate-like, fibrous, or amorphous. Among these, spherical shapes are preferred because they provide excellent dispersion stability and allow the production of cured products with high light transmittance and refractive index. The crystalline structure of the inorganic particles (B) is not particularly limited, but a monoclinic system is preferred because it provides excellent dispersion stability and a cured product with high light transmittance and refractive index.

[0036] <Photopolymerization initiator (C)> The photopolymerization initiator (C) will be explained below. The photopolymerization initiator (C) may be any of a photoradical polymerization initiator, a photoanionic polymerization initiator, and a photocationic polymerization initiator. Examples of the photopolymerization initiator (C) include benzoin compounds (C1), alkylphenone compounds (C2), anthraquinone compounds (C3), thioxanthone compounds (C4), ketal compounds (C5), benzophenone compounds (C6), phosphine oxides (C7), and oxime ester compounds (C8).

[0037] Examples of the benzoin compound (C1) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether. Examples of the alkylphenone compound (C2) include acetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone. Examples of the anthraquinone compound (C3) include 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-chloroanthraquinone, and 2-amylanthraquinone. Examples of the thioxanthone compound (C4) include 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 2-chlorothioxanthone. Examples of the ketal compound (C5) include acetophenone dimethyl ketal and benzyl dimethyl ketal. Examples of the benzophenone compound (C6) include benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 4,4'-bismethylaminobenzophenone. Examples of the phosphine oxide (C7) include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylethylphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. Examples of the oxime ester compound (C8) include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime) and ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime).

[0038] Of these photopolymerization initiators (C), 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylethylphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide are preferred from the viewpoint of curability. The photopolymerization initiator (C) may be used alone or in combination of two or more kinds.

[0039] <Dispersant (D)> The dispersant (D) will be explained below. The dispersant (D) is adsorbed onto the surface of the inorganic particles and serves to uniformly disperse the inorganic particles in the cured product. There are no particular restrictions on the dispersant (D), as long as it is a surfactant having at least one functional group selected from the group consisting of a carboxyl group, a phosphate group, a thiol group, a hydroxyl group, and an amino group. Examples of surfactants having a carboxyl group include saturated fatty acids having 12 to 36 carbon atoms (lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, isostearic acid, etc.) and salts thereof, monocarboxylic acids of alkylene oxide adducts (polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, etc.) and salts thereof, and compounds having a (meth)acryloyloxy group or a vinyl group and a carboxyl group (carboxyethyl (meth)acrylate, ω-carboxy-polycaprolactone mono(meth)acrylate, monohydroxyethyl phthalate (meth)acrylate, 2-acryloyloxyethyl succinate, 2-methacryloyloxyethyl succinate, 2-acryloyloxyethyl hexahydrophthalate, 2-methacryloyloxyethyl hexahydrophthalate, etc.) and salts thereof. Examples of surfactants having a phosphate group include alkyl phosphate esters having 4 to 36 carbon atoms (2-ethylhexyl acid phosphate, oleyl acid phosphate, etc.) and / or salts thereof, phosphate esters of alkylene oxide adducts (butoxyethyl acid phosphate, etc.) and salts thereof, and compounds having a (meth)acryloyloxy group or a vinyl group and a phosphorus group (2-methacryloyloxyethyl caproate acid phosphate, acid phosphooxypropylene glycol monomethacrylate, and 2-methacryloyloxyethyl acid phosphate (2-hydroxyethyl methacrylate acid phosphate), etc.) and salts thereof. Examples of surfactants having a thiol group include alkylthiols having 8 to 36 carbon atoms (such as 1-dodecanethiol) and aromatic thiols (such as 2-mercaptobenzothiazole). Examples of surfactants having a hydroxyl group include saturated alcohols having 8 to 36 carbon atoms (octanol, decanol, octadecanol, docosanol, triacontanol, etc.), alkylene oxide adducts of saturated alcohols having 8 to 36 carbon atoms (polyethylene glycol monolaurate, etc.), sorbitan fatty acid esters (sorbitan monostearate, sorbitan monolaurate, etc.), and compounds having a (meth)acryloyloxy group or a vinyl group and a hydroxyl group (2-hydroxyethyl (meth)acrylate, N-(2-hydroxyethyl)acrylamide, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, etc.). Examples of surfactants having an amino group include amine compounds having 8 to 36 carbon atoms (such as N,N-dimethyldodecylamine), and compounds having a (meth)acryloyloxy group or a vinyl group and an amino group (such as 2-(dimethylamino)ethyl methacrylate and N-[3-(dimethylamino)propyl]acrylamide).

[0040] Of these dispersants (D), from the viewpoint of dispersion stability, preferred are surfactants having a carboxyl group and surfactants having a phosphate group, more preferred are compounds having a (meth)acryloyloxy group or a vinyl group and a carboxyl group, and compounds having a (meth)acryloyloxy group or a vinyl group and a phosphorus group, and particularly preferred are carboxyethyl (meth)acrylate, ω-carboxy-polycaprolactone mono(meth)acrylate, monohydroxyethyl phthalate (meth)acrylate, 2-acryloyloxyethyl succinate, 2-methacryloyloxyethyl succinate, 2-acryloyloxyethyl hexahydrophthalate, 2-methacryloyloxyethyl hexahydrophthalate, 2-methacryloyloxyethyl caproate acid phosphate, acid phosphooxypropylene glycol monomethacrylate, 2-methacryloyloxyethyl acid phosphate, and 2-hydroxyethyl methacrylate acid phosphate.

[0041] From the viewpoint of dispersion stability and imprinting properties, the HLB of the dispersant (D) is preferably from 5 to 17.5, more preferably from 9.5 to 17.5. The HLB of the dispersant (D) can be adjusted by the ratio of the hydrophilic skeleton and the lipophilic skeleton introduced. The HLB value is a measure of the balance between hydrophilicity and lipophilicity, and the higher the HLB value, the higher the inorganicity. This is known as the value calculated by the Oda method described in, for example, "Introduction to Surfactants," 2007, Sanyo Chemical Industries, Ltd., by Takehiko Fujimoto, p. 212, and is not the value calculated by the Griffin method. The HLB value can be calculated from the ratio of the organicity value to the inorganicity value of an organic compound. HLB=10×Inorganic / Organic Here, the inorganic and organic values ​​in the above formula represent index values ​​that express organic and inorganic properties proposed by Fujita et al., and can be calculated using the values ​​in the table on page 213 of the aforementioned "Introduction to Surfactants."

[0042] Calculated from the Hansen solubility parameter (HSP) of the dispersant (D) {4 × (dD) 2 +(dP) 2 +(dH) 2} 0.5 From the viewpoint of dispersion stability and imprintability, the molecular weight is preferably 30 to 50, more preferably 35 to 50, and even more preferably 35 to 45. The Hansen solubility parameter (HSP) of the dispersant (D) can be adjusted by introducing a skeleton with different dipole moment or hydrogen bonding property. The definition and calculation of the Hansen solubility parameter are described in "Hansen Solubility Parameters: A Users Handbook (CRC Press, 2007)" by Charles M. Hansen, and the unit of the Hansen solubility parameter in the present invention is (cal / cm 3 ) 0.5Furthermore, by using the computer software "HSPiP5.4.08," it is possible to estimate the Hansen Solubility Parameters from the chemical structure of monomers for which parameter values ​​are not described in the literature. In the present invention, for monomers for which parameter values ​​are described in the literature, those values ​​are used, and for monomers for which parameter values ​​are not described in the literature, the values ​​in the list attached to "HSPiP5.4.08" are used, and for monomers not listed, parameter values ​​estimated using the Y-BM estimation method are used.

[0043] The active energy ray-curable composition of the present invention may contain other additives as needed within the range that does not impair the effects of the present invention. Examples of additives include organic solvents, release agents, antioxidants, hindered amine light stabilizers, ultraviolet absorbers, antistatic agents, colorants, polymerization inhibitors, chain transfer agents, fillers, plasticizers, and thixotropy-imparting agents (thickeners).

[0044] Examples of the organic solvent (E) include alcohols (methanol, ethanol, isopropanol, butanol, 3-methoxybutanol, octanol, and the like); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like); esters (ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, methoxybutyl acetate (3-methoxybutyl acetate), propylene glycol monomethyl ether acetate (2-methoxy-1-methylethyl acetate), propylene glycol monoethyl ether acetate, and the like); ethers (ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, and the like); aromatic hydrocarbons (benzene, toluene, xylene, and the like); and amides (dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like). Of these, from the viewpoint of compatibility with the active energy ray-curable composition of the present invention, methanol, isopropanol, butanol, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, ethyl acetate, 2-methoxy-1-methylethyl acetate, methoxybutyl acetate (3-methoxybutyl acetate), toluene, and xylene are preferred. The organic solvent (E) may be used alone or in combination of two or more kinds.

[0045] Examples of the release agent (F) include fluorine additives, acrylic leveling agents, and silicone leveling agents.

[0046] Examples of fluorine additives include BM-1000 and BM-1100 (all manufactured by BM CHEMIE), Megafac F-142D, F-172, F-173, F-183, F-178, F-471, F-477, F-444, F-552, and F-554 (all manufactured by DIC Corporation), and Surflon S-242, S-420, S-431, S-386, S-611, S-651, S-656, S-658, and S-693 (all manufactured by AGC Seimi Chemical Co., Ltd.). Examples of acrylic leveling agents include Disparlon UVX-36 (manufactured by Kusumoto Chemicals Co., Ltd.). Examples of silicone leveling agents include KP-423 (manufactured by Shin-Etsu Chemical Co., Ltd.) and Polyflow KL-401 (manufactured by Kyoeisha Co., Ltd.). The release agent (F) may be used alone or in combination of two or more kinds.

[0047] The weight proportion of the active energy ray-polymerizable compound (A) in the present invention is preferably 3% by weight to 50% by weight, more preferably 3% by weight to 30% by weight, based on the total weight of the active energy ray-polymerizable compound (A), inorganic particles (B), photopolymerization initiator (C), and dispersant (D). When the weight proportion of (A) is 3% by weight or more, the imprintability is good, and when it is 50% by weight or less, the refractive index of the cured product is good.

[0048] The weight proportion of the inorganic particles (B) in the present invention is preferably 48.9% by weight to 95.9% by weight, more preferably 68% by weight to 95% by weight, based on the total weight of the active energy ray-polymerizable compound (A), the inorganic particles (B), the photopolymerization initiator (C), and the dispersant (D). When the weight proportion of (B) is 48.9% by weight or more, the refractive index of the cured product becomes good, and when it is 95.9% by weight or less, the imprintability becomes good.

[0049] The weight proportion of the photopolymerization initiator (C) in the present invention is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight, and particularly preferably 1 to 3% by weight, based on the total weight of the active energy ray-polymerizable compound (A), the inorganic particles (B), the photopolymerization initiator (C), and the dispersant (D).

[0050] The weight proportion of the dispersant (D) in the present invention is preferably 1 to 20% by weight, more preferably 1 to 10% by weight, based on the total weight of the active energy ray-polymerizable compound (A), the inorganic particles (B), the photopolymerization initiator (C), and the dispersant (D). When the weight proportion of (D) is 1% by weight or more, the dispersion stability is good, and when it is 20% by weight or less, the refractive index of the cured product is good.

[0051] The weight proportion of the organic solvent (E) in the present invention is preferably 0.001% by weight to 800% by weight, more preferably 0.5% by weight to 700% by weight, and particularly preferably 1% by weight to 500% by weight, based on the total weight of the active energy ray-polymerizable compound (A), the inorganic particles (B), the photopolymerization initiator (C), and the dispersant (D).

[0052] The weight proportion of the other additives in the present invention is preferably 0.01% by weight to 10% by weight based on the total weight of the active energy ray-polymerizable compound (A), inorganic particles (B), photopolymerization initiator (C), and dispersant (D).

[0053] The active energy ray-curable composition of the present invention can be produced, for example, by uniformly mixing the active energy ray-polymerizable compound (A), inorganic particles (B), photopolymerization initiator (C), dispersant (D), and other additives using a known mechanical mixing method (a method using a mechanical stirrer, a magnetic stirrer, or the like). The inorganic particles (B) may be dispersed in an organic solvent (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and propylene glycol monomethyl ether acetate). In order to adjust the weight ratio of the organic solvent to a desired amount, the organic solvent may be distilled off under reduced pressure.

[0054] <Cured product> The cured product of the present invention is obtained by distilling off the organic solvent from the active energy ray-curable composition of the present invention and curing the composition, and can be obtained, for example, by irradiating a coating film obtained by molding the active energy ray-curable composition of the present invention with active energy rays to cure the coating film. Examples of active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays, electron beams, etc. Ultraviolet rays refer to light rays with a wavelength of 200 nm to 410 nm. The wavelength of the active energy ray is not particularly limited as long as it can cure the composition, but is preferably 350 nm to 410 nm. A typical example of the active energy ray is light with a wavelength of 365 nm. The irradiation intensity of the active energy rays is not particularly limited as long as it can cure the composition, but is preferably 20 mW / cm 2 ~20,000mW / cm 2 It is preferable that: The cumulative exposure dose of active energy rays is 100 mJ / cm 2 ~30,000mJ / cm 2 The irradiation time may be determined depending on the irradiation intensity.

[0055] When using ultraviolet light as the active energy ray, the light source can be a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a high-power metal halide lamp, etc. (Latest Trends in UV / EB Curing Technology, edited by RadTech Research Group, CMC Publishing, p. 138, 2006), or an LED. Compared to other light sources, LEDs consume less power and generate less ozone, resulting in lower running costs and a lower environmental impact. When curing with an LED light source, an LED light source ultraviolet irradiation device [e.g., LED light source ultraviolet irradiation device "FJ100" 150 x 20 365, manufactured by Phoseon Technology Co., Ltd.] can be used.

[0056] The shape of the portion irradiated with active energy rays may be an area type having a certain area or a line type. In the case of a line type, the entire coating film can be irradiated with light by moving the coating film relative to the light source or by moving the light source relative to the coating film. In the case of a line type, the irradiation time can be easily adjusted, and therefore the cumulative exposure amount can be easily adjusted.

[0057] Irradiation with active energy rays may be carried out in the atmosphere. Because the composition of the present invention has good reactivity, the reaction of the composition can be allowed to proceed and cured even in the atmosphere. It is particularly preferable to irradiate the composition with active energy rays in a dry atmosphere to cure it. In this case, moisture absorption by the cured composition can be suppressed.

[0058] In the present invention, the cured product may be further heated. Heating further promotes curing, thereby lowering the linear expansion coefficient of the cured product. When further heating is performed, the heating temperature is preferably 90°C or higher.

[0059] The active energy ray-curable composition of the present invention can be cured to produce a molded article that can be suitably used as an optical component (optical lens, sheet for optical lens, film, coating material for decorative film, coating material for optical fiber, hard coat film, antireflection film, etc.).

[0060] A method for producing a molded article by curing the active energy ray-curable composition of the present invention will be described below. The method for producing the optical component using the active energy ray-curable composition of the present invention is not particularly limited, and for example, coating and molding can be performed by the following method: That is, the composition of the present invention is coated onto a transparent substrate (including a transparent film) using a bar coater or the like so that the thickness after curing is 50 nm to 150 μm, a mold is pressed onto the coated film, and the coated film is cured by irradiating the transparent substrate with active energy rays described below, and then the optical component is released from the mold.

[0061] Examples of the transparent substrate (including transparent film) include those made of glass, methyl methacrylate (co)polymer, polyethylene terephthalate, polycarbonate, polytriacetyl cellulose, polycycloolefin, and other resins. [Example]

[0062] The present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, "parts" below refer to parts by weight.

[0063] <Preparation of active energy ray-curable composition> (Examples 1 to 10 and Comparative Examples 1 to 3) According to the blending parts (parts by weight) in Table 1, the active energy ray-polymerizable compound (A), inorganic particles (B), photopolymerization initiator (C), dispersant (D), organic solvent (E) and release agent (F) were charged into a glass container and stirred until homogeneous, thereby obtaining the active energy ray-curable compositions of Examples 1 to 10 and Comparative Examples 1 to 3.

[0064] [Table 1]

[0065] The raw materials used in Table 1 are as follows:

[0066] (A-1): o-phenoxyphenylethyl acrylate [A-LEN-10: manufactured by Shin-Nakamura Chemical Co., Ltd., refractive index (25°C): 1.58] (A-2): m-phenoxybenzyl acrylate [POB-A: manufactured by Kyoeisha Chemical Co., Ltd., refractive index (25°C): 1.57] (A-3) (Naphthyl)methyl acrylate [NMT-A: manufactured by Kyoeisha Chemical Co., Ltd., refractive index (25°C): 1.60] (A-4): 4-biphenylmethylacrylate [KOMERATE H008: manufactured by Green Chemical Co., Ltd., refractive index (25°C): 1.60] (A-5): Dinaphthothiophene derivative [6MDNTA: manufactured by Sugai Chemical Industry Co., Ltd., refractive index (25°C): 1.71] (A-6): 4,4'-bisacryloxymethylbiphenyl [DABP: manufactured by JFE Chemical Corporation, refractive index (25°C): 1.59] (A-7): Bis(4-methacryloylthiophenyl) sulfide [manufactured by Nacalai Tesque, Inc., refractive index (25°C): 1.66] (A-8): 1,1'-thiobis(4-ethenylthiobenzene) [Fujifilm Wako Pure Chemical Industries, Ltd., refractive index (25°C): 1.69] (A-9): Binaphthol derivative [BINLA: manufactured by Sugai Chemical Industry Co., Ltd., refractive index (25°C): 1.64] (A-10): Fluorene diacrylate [Oxol EA-200: manufactured by Osaka Gas Chemicals Co., Ltd., refractive index (25°C): 1.62] (A-11): Dimethylol-tricyclodecane diacrylate [Light Acrylate DCP-A: manufactured by Kyoeisha Co., Ltd., refractive index (25°C): 1.50] (A-12): Dimethylol-tricyclodecane dimethacrylate [DCP: manufactured by Shin-Nakamura Chemical Co., Ltd., refractive index (25°C): 1.50] (A-13): Dipentaerythritol hexaacrylate [Neomer DA-600: manufactured by Sanyo Chemical Industries, Ltd., refractive index (25°C): 1.47]

[0067] (B-1): A solution of barium titanate (BaTiO3) particles dispersed in propylene glycol monomethyl ether [product name "9714BT", solid content: 15% by weight, number average particle diameter of barium titanate particles: approximately 40 nm, manufactured by Tokushiki Corporation] (B'-1): Titanium oxide (TiO2) particles [trade name "TTO-51(C)", titanium oxide particle diameter 10-30 nm, manufactured by Ishihara Sangyo Kaisha, Ltd.]

[0068] (C-1): 2,4,6-trimethylbenzoyldiphenylphosphine oxide (trade name "IRGACURE TPO", manufactured by BASF) (C-2): 2,4,6-trimethylbenzoylethylphenylphosphine oxide (trade name "Omnirad TPO-L", manufactured by IGM Resins BV) (C-3): 1-hydroxycyclohexyl phenyl ketone [trade name "Irgacure 184", manufactured by BASF]

[0069] (D-1): Isostearic acid [Isostearic acid: Nissan Chemical Co., Ltd., HLB: 5.2, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =33] (D-2): 2-acryloyloxyethyl hexahydrophthalic acid [HOA-HH: Kyoeisha Chemical Co., Ltd., HLB: 11.4, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =36]] (D-3): 2-Acryloyloxyethyl succinic acid [HOA-MS: Kyoeisha Chemical Co., Ltd., HLB: 15.2, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =37]] (D-4): 2-methacryloyloxyethyl caproate acid phosphate [KAYAMER PM-21: manufactured by Nippon Kayaku Co., Ltd., HLB: 5.3, {4×(dD) 2 +(dP) 2 +(dH)2} 0.5 =36] (D-5): Acid phosphoxypropylene glycol monomethacrylate [Hosmer PP: manufactured by Unichemical Co., Ltd., HLB: 5.1, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =42] (D-6): 2-Methacryloyloxyethyl acid phosphate [Light Ester P-1M: manufactured by Kyoeisha Chemical Co., Ltd., HLB: 14.7, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =49] (D-7): 2-mercaptobenzothiazole [Suncerer M: manufactured by Sanshin Chemical Industry Co., Ltd., HLB: 2.0, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =48] (D-8): Polyethylene glycol monolaurate [Emanon 1112: manufactured by Kao Corporation, HLB: 13.7, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =34] (D-9): N-(2-hydroxyethyl)acrylamide [HEAA: manufactured by KJ Chemicals Co., Ltd., HLB: 30.2, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =43]] (D-10): N-[3-(dimethylamino)propyl]acrylamide [DMAPAA: manufactured by KJ Chemicals, Inc., HLB: 17, {4×(dD) 2 +(dP) 2 +(dH) 2} 0.5 =36]]

[0070] (E-1): 2-Methoxy-1-methylethyl acetate [PGMEA: Fujifilm Wako Pure Chemical Industries, Ltd.] (E-2): 3-Methoxybutyl acetate [MBA: Fujifilm Wako Pure Chemical Industries, Ltd.] (E-3): Cyclohexanone [Fujifilm Wako Pure Chemical Industries, Ltd.]

[0071] (F-1): Fluorine additive [F-444: manufactured by DIC Corporation]

[0072] The active energy ray-curable compositions prepared in the examples and comparative examples were evaluated for viscosity, refractive index, light resistance, imprintability, and dispersion stability by the following methods.

[0073] <Viscosity measurement> The mixtures of active energy ray-polymerizable compounds (A) used in Examples 1 to 10 and Comparative Examples 1 to 3 were kept at 25°C for 30 minutes, and the viscosities (mPa s) were measured under the following conditions using an E-type viscometer ["VISCOMETER TV-25L" manufactured by Toki Sangyo Co., Ltd.]. [Measurement conditions] Cone rotor: Standard cone rotor (1°34' x R24) Measurement temperature: 25℃ Measurement range: M Rotation speed: 50 rpm

[0074] <Method for preparing cured products for evaluating refractive index and light resistance> 1 g of the active energy ray-curable composition was dropped onto a 10 cm square glass substrate [Eagle XG, manufactured by Corning Incorporated] and applied by spin coating at 3000 rpm for 30 seconds, then dried at 100°C for 3 minutes, and then irradiated with ultraviolet light at 10000 mJ / cm using an ultraviolet irradiation device [VPS / I600, manufactured by Fusion UV Systems Co., Ltd.] under a nitrogen atmosphere. 2 The coating was irradiated and cured to obtain a cured product with a film thickness of 100 nm for evaluation of refractive index and light resistance.

[0075] <Refractive index> The refractive index of the cured product prepared as described above at 589 nm was measured using a reflection spectrophotometer [FE-3000, manufactured by Otsuka Electronics Co., Ltd.]. In this case, a refractive index of 1.60 or higher is considered to be satisfactory.

[0076] <Light resistance> The cured products for evaluation prepared as described above were subjected to a light resistance test using an Eye Super UV Tester SUV-W131 (illuminance: 25 mW / cm 2 The degree of coloring of the resin was visually observed, the change in refractive index was measured, and the results were evaluated according to the following criteria. ◎: No coloring, change in refractive index less than 0.1 Good: No coloring, and the change in refractive index is 0.1 or more and less than 0.2 ×: Coloration or refractive index change of 0.2 or more

[0077] <Imprintability> (1) The active energy ray-curable composition was dropped onto a glass substrate [Eagle XG, manufactured by Corning] and applied by spin coating at 500 rpm for 30 seconds, and then dried at 100°C for 3 minutes. (2) The resin obtained in (1) was attached to a mold (DTM-3-1 manufactured by Kyodo International Co., Ltd.), and a roller was rolled over it to remove any air. UV light was applied from the glass side using a UV irradiation device [model number "VPS / I600" manufactured by Fusion UV Systems Co., Ltd.] at 1000 mJ / cm. 2 It was irradiated and cured. (3) The mold in (2) was removed, and the surface of the cured product was observed with an SEM and evaluated according to the following criteria. ◎: 80% or more of the irregularities are transferred. ◯: 30% to less than 80% of the irregularities are transferred. ×: Less than 30% of the irregularities were transferred.

[0078] <Dispersion stability> The active energy ray-curable composition was stored at 25°C for one month or three months. Whether the particle dispersion state was maintained after storage was evaluated. If there was no visible change and the particles did not settle after one month but settled or gelled after three months, the result was marked "Good." If the particles did not settle after three months, the result was marked "Excellent." If the coated particles settled after one month or if a clear increase in viscosity and gelling occurred, the result was marked "Poor."

[0079] As can be seen from the results in Table 1, Comparative Examples 1 and 2, which did not contain dispersant (D), had poor dispersion stability. Furthermore, Comparative Example 3, which used an active energy ray-curable composition that used titanium oxide as the inorganic particles (B) but did not use barium titanate, had poor light resistance. In contrast, each of the Examples provided cured products that showed good results in all categories. [Industrial Applicability]

[0080] The cured product of the active energy ray-curable composition of the present invention has a high refractive index and is therefore useful as an optical member, specifically as an optical component such as a plastic lens (e.g., a prism lens, a lenticular lens, a microlens, a Fresnel lens, or a viewing angle improving lens), an optical compensation film, a retardation film, a prism, an optical fiber, a solder resist for flexible printed wiring, a plating resist, an interlayer insulating film for multilayer printed wiring boards, or a photosensitive optical waveguide.

Claims

1. An active energy ray-curable composition comprising an active energy ray-polymerizable compound (A), inorganic particles (B), a photopolymerization initiator (C), and a dispersant (D), wherein the inorganic particles (B) are BaTiO having a number average particle diameter of 5 to 40 nm. ３ and the dispersant (D) is a surfactant having at least one functional group selected from the group consisting of a carboxyl group, a phosphate group, a thiol group, a hydroxyl group, and an amino group.

2. The active energy ray-curable composition according to claim 1 , wherein the active energy ray-polymerizable compound (A) contains a monofunctional monomer (A1) and a polyfunctional monomer (A2).

3. 2. The active energy ray-curable composition according to claim 1, wherein the monofunctional monomer (A1) is at least one monomer selected from the group consisting of alicyclic skeleton-containing mono(meth)acrylates, aromatic ring skeleton-containing mono(meth)acrylates, and heterocyclic skeleton-containing mono-N-(meth)acrylamides.

4. The active energy ray-curable composition according to claim 1, wherein the polyfunctional monomer (A2) is a polyfunctional (meth)acrylate compound and / or a polyfunctional vinyl sulfide compound.

5. 2. The active energy ray-curable composition according to claim 1, wherein the dispersant (D) is contained in an amount of 1% by weight to 20% by weight based on the total weight of the active energy ray-polymerizable compound (A), the inorganic particles (B), the photopolymerization initiator (C), and the dispersant (D).

6. A cured product of the active energy ray-curable composition according to any one of claims 1 to 5.

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