Anti-reflection film and method for producing anti-reflection film

Abstract

Provided are: an antireflection film having high antireflection properties and excellent scratch resistance; and a method for producing such an antireflection film. An antireflection film (10) having a base film (12), a hard coat layer (14) formed on a surface of the base film (12), a high refractive index layer (16) formed on a surface of the hard coat layer (14), and a low refractive index layer (18) formed on a surface of the high refractive index layer (16), the high refractive index layer (16) comprising a cured product of an ionizing radiation curable composition, the ionizing radiation curable composition contains a (meth) acrylate compound having a reactive group and titanium oxide particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the (meth) acrylate compound. The titanium oxide particles have an average particle diameter (D50) of 20 nm or more in the cumulative particle size distribution on a volume basis, and a 90% particle diameter (D90) of 120 nm or less in the cumulative particle size distribution on a volume basis.

Description

Technical Field

[0001] The present invention relates to an antireflection film and a method for producing the antireflection film, and more particularly to an antireflection film suitable for use on the display surface of a liquid crystal display, an organic EL display, a touch panel of a smartphone, etc., and a method for producing such an antireflection film. Background Art

[0002] In order to prevent external light from being reflected into the screen, etc., an anti-reflection film is sometimes configured on the display surface of a liquid crystal display, an organic EL display, a touch panel of a smart phone, etc. For example, Patent Document 1 discloses an anti-reflection film having a medium refractive index layer, a high refractive index layer, and a low refractive index layer on a substrate film. As a composition constituting the high refractive index layer, a mixture of titanium oxide and urethane acrylate can be cited.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-55659 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In recent years, with the popularization of displays that are designed to be operated outdoors by touch, such as smartphones and car navigation systems, there is an increasing demand for anti-reflection films that have high anti-reflection properties and are not easily damaged even when touch operations are repeated. However, although the anti-reflection film of Patent Document 1 has excellent anti-reflection properties, it cannot be said that it has sufficient scratch resistance for use on the surface of displays such as mobile terminals, and further higher scratch resistance is required.

[0008] The problem to be solved by the present invention is to provide an antireflection film having high antireflection properties and excellent scratch resistance, and a method for producing such an antireflection film.

[0009] Solutions for solving problems

[0010] In order to solve the above-mentioned problems, the antireflection film involved in the present invention is characterized in that it has a substrate film, a hard coating layer formed on the surface of the substrate film, a high refractive index layer formed on the surface of the hard coating layer, and a low refractive index layer formed on the surface of the high refractive index layer, wherein the high refractive index layer is composed of a cured product of an ionizing radiation curable composition, the ionizing radiation curable composition contains a (meth)acrylate compound having a reactive group and titanium oxide particles surface-treated by a silane coupling agent having a reactive group capable of forming a bond with the (meth)acrylate compound, the average particle size D50 of the titanium oxide particles in the cumulative particle size distribution based on volume is greater than 20 nm, and the 90% particle size D90 in the cumulative particle size distribution based on volume is less than 120 nm.

[0011] Here, the refractive index of the high refractive index layer at a wavelength of 550nm may be greater than 1.83 and less than 2.00, and the refractive index of the low refractive index layer at a wavelength of 550nm may be greater than 1.35 and less than 1.49. In addition, the anti-reflection film may have a medium refractive index layer between the hard coating layer and the high refractive index layer, the refractive index of which at a wavelength of 550nm is higher than that of the hard coating layer and lower than that of the high refractive index layer.

[0012] The present invention relates to a method for producing an antireflection film, wherein a hard coating layer is formed on the surface of a substrate film, an ionizing radiation curable composition is applied on the surface of the hard coating layer to form a high refractive index layer, the ionizing radiation curable composition containing a (meth)acrylate compound having a reactive group and a particle dispersion in which titanium oxide particles surface-treated by a silane coupling agent having a reactive group capable of forming a bond with the (meth)acrylate compound are dispersed in a solvent, and a low refractive index layer is formed on the surface of the high refractive index layer. In the method for producing an antireflection film, in the particle dispersion, the content of titanium atoms is 40% by mass or more and 80% by mass or less relative to 100% by mass of the total solid content.

[0013] Effects of the Invention

[0014] The antireflection film according to the present invention comprises a substrate film, a hard coating layer formed on the surface of the substrate film, a high refractive index layer formed on the surface of the hard coating layer, and a low refractive index layer formed on the surface of the high refractive index layer, wherein the high refractive index layer is composed of a cured product of an ionizing radiation curable composition, wherein the ionizing radiation curable composition contains a (meth)acrylate compound having a reactive group and titanium oxide particles surface-treated by a silane coupling agent having a reactive group capable of forming a bond with the (meth)acrylate compound, wherein the average particle size D50 in the cumulative particle size distribution based on volume is 20 nm or more, and the 90% particle size D90 in the cumulative particle size distribution based on volume is 120 nm or less, so the film has high antireflection properties and excellent scratch resistance. The titanium oxide particles contained in the high refractive index layer are surface-treated by a silane coupling agent having a reactive group capable of forming a bond with the (meth)acrylate compound, and D50 and D90 are within the above-specified ranges, which bring about a high effect of achieving both antireflection properties and scratch resistance.

[0015] Here, when the refractive index of the high refractive index layer at a wavelength of 550 nm is 1.83 to 2.00 and the refractive index of the low refractive index layer at a wavelength of 550 nm is 1.35 to 1.49, the antireflection film can achieve both improved scratch resistance and low reflectivity.

[0016] In addition, when the antireflection film has a medium refractive index layer between the hard coat layer and the high refractive index layer, the antireflection property of the antireflection film can be further improved.

[0017] The method for manufacturing an anti-reflection film of the present invention forms a hard coating layer on the surface of a substrate film, and forms a high refractive index layer by applying an ionizing radiation curable composition on the surface of the hard coating layer, wherein the ionizing radiation curable composition contains a (meth) acrylate compound having a reactive group and a particle dispersion formed by dispersing titanium oxide particles surface-treated by a silane coupling agent having a reactive group capable of forming a bond with the (meth) acrylate compound in a solvent, and forms a low refractive index layer on the surface of the high refractive index layer. In the method for manufacturing an anti-reflection film, in the particle dispersion, the content of titanium atoms is 40% by mass or more and 80% by mass or less relative to a total of 100% by mass of the solid content, thereby being able to manufacture an anti-reflection film having high anti-reflectivity and excellent scratch resistance. Here, by setting the content of titanium atoms in the particle dispersion to the above range, a high-quality high refractive index layer having a high refractive index and high scratch resistance can be suitably manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of the antireflection film according to the first embodiment of the present invention.

[0019] Figure 2 It is a cross-sectional view of an antireflection film according to a second embodiment of the present invention.

[0020] Figure 3 It is a cross-sectional view of an antireflection film according to a third embodiment of the present invention.

[0021] Figure 4 It is a cross-sectional view of an antireflection film according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0022] In the present specification, various physical properties refer to values ​​at room temperature and in the atmosphere unless otherwise specified.

[0023] <Anti-reflection film according to first embodiment>

[0024] Figure 1 1 is a cross-sectional view of an antireflection film according to a first embodiment of the present invention. Figure 1 As shown, the anti-reflection film 10 involved in the first embodiment of the present invention comprises: a substrate film 12; a hard coating layer 14, which is formed on the surface of the substrate film 12; a high refractive index layer 16, which is formed on the surface of the hard coating layer 14; and a low refractive index layer 18, which is formed on the surface of the high refractive index layer 16. The anti-reflection film 10 has a substrate film 12, a hard coating layer 14, a high refractive index layer 16, and a low refractive index layer 18 in order. Preferably, the substrate film 12 and the hard coating layer 14 can be in direct contact without other layers. In addition, the high refractive index layer 16 and the low refractive index layer 18 can be in direct contact without other layers. In this embodiment, the hard coating layer 14 and the high refractive index layer 16 are also in direct contact without other layers.

[0025] (Base film)

[0026] The substrate film 12 is not particularly limited as long as it has transparency. As the substrate film 12, transparent polymer films, glass films, etc. can be listed. Transparency refers to a total light transmittance of 50% or more in the visible light wavelength region, and the total light transmittance is more preferably 85% or more. The above-mentioned total light transmittance can be measured in accordance with JIS K7361-1 (1997). The thickness of the substrate film 12 is not particularly limited, but from the viewpoint of excellent operability, it is preferably in the range of more than 2μm and less than 500μm. More preferably, it is in the range of more than 2μm and less than 200μm. In addition, "film" generally refers to a film with a thickness of less than 0.25mm, but if the thickness is more than 0.25mm and can be rolled into a roll, even if it is a film with a thickness of more than 0.25mm, it is also included in the "film".

[0027] As the polymer material of the substrate film 12, polyester resins such as polyethylene terephthalate resin and polyethylene naphthalate resin, polycarbonate resin, poly (meth) acrylate resin, polystyrene resin, polyamide resin, polyimide resin, polyacrylonitrile resin, polypropylene resin, polyethylene resin, polycycloolefin resin, cycloolefin copolymer resin and other polyolefin resins, triacetyl cellulose resin, diacetyl cellulose resin and other cellulose resins, polyphenylene sulfide resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, etc. can be listed. The polymer material of the substrate film 12 can be composed of only one of them, or it can be composed of a combination of more than two kinds. Among them, from the viewpoints of optical properties or durability, polyethylene terephthalate resin, polyimide resin, polycarbonate resin, poly (meth) acrylate resin, polycycloolefin resin, cycloolefin copolymer resin, triacetyl cellulose resin is more preferred.

[0028] The substrate film 12 may be composed of a single layer including a layer containing one or more of the above-mentioned polymer materials, or may be composed of two or more layers including a layer containing one or more of the above-mentioned polymer materials and a layer containing one or more polymer materials different from the layer.

[0029] (Hard Coating)

[0030] The hard coating layer 14 helps to improve the scratch resistance of the anti-reflection film 10. The hard coating layer 14 is composed of a cured product of an ionizing radiation curable composition containing a (meth) acrylate compound having a reactive group. Ionizing radiation refers to an electromagnetic wave or charged particle beam having an energy quantum that can polymerize or crosslink molecules among electromagnetic waves or charged particle beams. As ionizing radiation, electromagnetic waves such as ultraviolet rays (UV), X-rays, and gamma rays, charged particle beams such as electron beams (EB), alpha rays, and ion beams can be listed. Among them, ultraviolet rays (UV) are particularly preferred from the perspective of productivity. Hereinafter, the ionizing radiation curable composition is sometimes referred to as a curable composition. In addition, in this specification, "(meth) acrylate" refers to "at least one of acrylate and methacrylate". "(Meth) acryl" refers to "at least one of acryloyl and methacryloyl". "(Meth) acrylic acid" refers to "at least one of acrylic acid and methacrylic acid". "(Meth) acrylic acid" refers to "at least one of acrylic acid and methacrylic acid". "(Meth) acrylic acid compound" is a compound having a (meth) acrylic acid group, and monomers, oligomers, prepolymers, etc. can be listed. Hereinafter, the (meth)acrylate compound may be simply referred to as (meth)acrylate.

[0031] The (meth)acrylate may be a monofunctional (meth)acrylate or a multifunctional (meth)acrylate. Alternatively, it may be a combination of a monofunctional (meth)acrylate and a multifunctional (meth)acrylate. From the viewpoint of improving curability, the curable composition more preferably contains a multifunctional (meth)acrylate as the (meth)acrylate.

[0032] As (meth) acrylate, carbamate (meth) acrylate, silicone (meth) acrylate, (meth) alkyl acrylate, (meth) aryl acrylate, etc. can be listed. Among them, carbamate (meth) acrylate is preferred, and carbamate (meth) acrylate oligomer is particularly preferred. As a specific example of carbamate (meth) acrylate, for example, a substance obtained by reacting a polyisocyanate compound, a hydroxyl-containing (meth) acrylate compound, and a polyol compound as required can be listed. As a polyisocyanate compound, for example, diisocyanate compounds such as hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and their urate modified bodies, adduct modified bodies, biuret modified bodies, etc. can be listed. As a hydroxyl-containing (meth) acrylate compound, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, trimethylolpropane diacrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate and their polyoxyalkylene (Polyoxyalkylene) modified bodies, polylactone modified bodies, etc. can be listed. As a polyol compound, for example, ethylene glycol, propylene glycol, butanediol, hexanediol, polyoxyethylene glycol, polyoxypropylene glycol, glycerol, trimethylolpropane, pentaerythritol, biphenol, bisphenol, etc. can be listed. In the case where the curable composition for forming the hard coating 14 includes carbamate (meth) acrylate as an ultraviolet curable resin, since the hard coating 14 has moderate softness, the bending resistance of the anti-reflection film 10 becomes high, and it can be suitably used for flexible displays that are repeatedly bent such as foldable displays or rollable displays. Furthermore, even if the base film 12 is made of polycycloolefin or cycloolefin copolymer, which is relatively easy to break, the breakage of the base film 12 can be easily suppressed.

[0033] As the (meth)acrylate constituting the curable composition, it is preferred to further contain a pentaerythritol (meth)acrylate compound. As specific examples of the pentaerythritol (meth)acrylate compound, pentaerythritol tri (meth)acrylate, pentaerythritol tetra (meth)acrylate, dipentaerythritol penta (meth)acrylate, dipentaerythritol hexa (meth)acrylate, tripentaerythritol tetra (meth)acrylate, tripentaerythritol penta (meth)acrylate, tripentaerythritol hexa (meth)acrylate, tripentaerythritol hepta (meth)acrylate, tripentaerythritol octa (meth)acrylate, etc. can be cited. It is particularly preferred to contain pentaerythritol tri (meth)acrylate in the curable composition.

[0034] In the curable composition forming the hard coat 14, in addition to including the ultraviolet curable resin, non-ultraviolet curable resin may also be included, but it may not be included. In addition, in the curable composition forming the hard coat 14, a photopolymerization initiator may also be included. In addition, as required, additives that can be usually added to the curable composition may also be included. As additives, dispersants, leveling agents, defoamers, thixotropic agents, antifouling agents, antibacterial agents, flame retardants, slip agents, antistatic agents, inorganic particles, resin particles, etc. may be listed. In addition, as required, a solvent may also be included.

[0035] As non-ultraviolet curable resins, thermoplastic resins, thermosetting resins, etc. can be listed. As thermoplastic resins, polyester resins, polyether resins, polyolefin resins, polyamide resins, etc. can be listed. As thermosetting resins, unsaturated polyester resins, epoxy resins, alkyd resins, phenolic resins, etc. can be listed.

[0036] Examples of the photopolymerization initiator include alkylphenone-based, acylphosphine oxide-based, and oxime ester-based photopolymerization initiators. Examples of the alkylphenone-based photopolymerization initiator include 2,2'-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1 -ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2-benzylmethyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-morpholinophenyl)-1-butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, N,N-dimethylaminoacetophenone, etc. Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide. Examples of the oxime ester photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), etc. The photopolymerization initiator may be used alone or in combination of two or more.

[0037] The content of the photopolymerization initiator is preferably in the range of 0.1% by mass or more and 10% by mass, and more preferably 1% by mass or more and 5% by mass or less, based on the total solid content of the curable composition.

[0038] Inorganic particles and resin particles are added to the hard coating layer 14 for the purpose of preventing the hard coating layer 14 from sticking or adjusting the refractive index of the hard coating layer 14. By forming minute surface irregularities on the hard coating layer 14 with the added inorganic particles or resin particles, it is easy to suppress sticking of the front and back surfaces when the hard coating film including the base film 12 and the hard coating layer 14 is rolled into a roll before forming the high refractive index layer 16.

[0039] As inorganic particles capable of adjusting the refractive index of the hard coating 14, metal oxide particles including oxides of metals such as titanium, zirconium, tin, zinc, silicon, niobium, aluminum, chromium, magnesium, germanium, gallium, antimony, and platinum can be listed. As inorganic particles capable of optical adjustment, one kind can be used alone, or two or more kinds can be used in combination. Among them, from the viewpoints of taking into account high refractive index and excellent transparency, titanium oxide and zirconium oxide are particularly preferred. In addition, as resin particles, for example, resin particles including resins such as (meth) acrylic resin, styrene resin, styrene-(meth) acrylic resin, urethane resin, polyamide resin, silicone resin, epoxy resin, phenolic resin, polyethylene resin, and cellulose can be listed. As resin particles, one kind can be used alone, or two or more kinds can be used in combination.

[0040] The thickness of the hard coating layer 14 is not particularly limited, but is preferably 0.5 μm or more from the viewpoint of having sufficient hardness, etc. More preferably, it is 0.75 μm or more. In addition, from the viewpoint of easily suppressing curling caused by the difference in thermal shrinkage with the base film 12, it is preferably 20 μm or less. More preferably, it is 10 μm or less. The thickness of the hard coating layer 14 refers to the thickness of a relatively smooth portion of a portion without unevenness caused by inorganic particles or resin particles in the thickness direction.

[0041] The refractive index of the hard coat layer 14 is preferably within a range of 1.49 to 1.56 from the viewpoint of suppressing interference unevenness caused by the difference in refractive index between the transparent base film 12 and the hard coat layer 14 .

[0042] From the viewpoint of preventing blocking, etc., the arithmetic mean roughness Ra of the surface having surface irregularities of the hard coat layer 14 is preferably within a range of 0.3 nm to 20 nm, and more preferably 0.5 nm to 10 nm.

[0043] As the solvent used in the curable composition for forming the hard coating layer 14, there can be listed: alcohol solvents such as ethanol, isopropyl alcohol (IPA), n-butyl alcohol (NBA), ethylene glycol monomethyl ether (EGM), ethylene glycol monoisopropyl ether (IPG), propylene glycol monomethyl ether (PGM), diethylene glycol monobutyl ether, etc.; ketone solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, acetone, etc.; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate (EtAc), propyl acetate, isopropyl acetate, butyl acetate (BuAc), etc.; amide solvents such as N-methylpyrrolidone, acetamide, dimethylformamide, etc. These solvents can be used alone or in combination of two or more.

[0044] The solid content concentration (concentration of components other than the solvent) of the curable composition may be appropriately determined in consideration of coating properties, film thickness, etc. For example, it may be 1% by mass to 90% by mass, 1.5% by mass to 80% by mass, 2% by mass to 70% by mass, etc.

[0045] (High refractive index layer)

[0046] In the anti-reflection film 10 involved in this embodiment, the high refractive index layer 16 is provided on the surface of the hard coating layer 14. By providing the high refractive index layer 16 between the hard coating layer 14 and the low refractive index layer 18, the anti-reflection film 10 exhibits a high anti-reflection effect. The high refractive index layer 16 is a layer having a higher refractive index than the hard coating layer 14 and the low refractive index layer 18.

[0047] The high refractive index layer 16 is composed of a cured product of an ionizing radiation curable composition containing a (meth) acrylate compound having a reactive group and titanium oxide particles surface-treated by a silane coupling agent having a reactive group capable of forming a bond with the (meth) acrylate compound. As described above for the hard coat layer, the ionizing radiation includes various electromagnetic waves and charged particle beams, but ultraviolet rays (UV) are particularly preferred. In addition, the reactive groups contained in the (meth) acrylate compound and the silane coupling agent are preferably ultraviolet reactive.

[0048] Examples of the (meth)acrylate compound having a reactive group include urethane (meth)acrylate, silicone (meth)acrylate, alkyl (meth)acrylate, aryl (meth)acrylate, etc. The (meth)acrylate compound may have only a (meth)acryloyl group as a reactive group, or may have another reactive group in addition to the (meth)acryloyl group.

[0049] The (meth)acrylate may be composed of only a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, or a combination of a monofunctional (meth)acrylate and a polyfunctional (meth)acrylate. As the (meth)acrylate, it is more preferable to contain a polyfunctional (meth)acrylate.

[0050] Examples of the monofunctional (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, , nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecyl (meth) acrylate, dimethicone Cyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 1-naphthylmethyl (meth)acrylate, 2-naphthylmethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxy-2-methylethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, 2-phenylphenoxyethyl (meth)acrylate, 4-phenylphenoxyethyl (meth)acrylate, 3-(2-phenylphenyl) ...3-(2-phenylphenyl)-2-hydroxypropyl (meth)acrylate, 3- )-2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and the like.

[0051] Examples of the polyfunctional (meth)acrylate include difunctional (meth)acrylate, trifunctional (meth)acrylate, and tetrafunctional (meth)acrylate. More specifically, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol tetra(meth)acrylate, tripentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, etc. can be mentioned.

[0052] The (meth)acrylate having a reactive group may be composed of one kind alone or of two or more kinds.

[0053] Preferably, the multifunctional (meth)acrylate contains a dimer. The dimer of the multifunctional (meth)acrylate can easily improve the curing rate of the curable composition due to its excellent curing speed, so the scratch resistance can be further improved. Among them, it is preferred to include at least one selected from the group including dimers of pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate, and more preferably at least one selected from the group including dimers of pentaerythritol triacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate.

[0054] From the viewpoint of scratch resistance, transparency, and solubility in solvents, the content of the dimer is preferably in the range of 25% by mass or more and 50% by mass or less based on the total solid content of the (meth)acrylate compound, and more preferably 30% by mass or more and 40% by mass or less.

[0055] The titanium oxide particles are used to increase the refractive index of the high refractive index layer 16 .

[0056] As the crystal structure of titanium oxide, rutile type, anatase type, brookite type, etc. are known, but rutile type is preferred from the viewpoint of high refractive index, low photocatalytic activity, etc. By using titanium oxide particles with low photocatalytic activity, the modification of the high refractive index layer 16 caused by the photoreaction can be suppressed.

[0057] The shape of the titanium oxide particles is not particularly limited, and may be spherical, needle-shaped, scaly, rod-shaped, fibrous, amorphous, etc. The titanium oxide particles are preferably solid.

[0058] The titanium oxide particles are surface treated by a silane coupling agent having a reactive group that can form a bond with a (meth) acrylate compound. By performing surface treatment with a silane coupling agent, the photocatalytic activity of the titanium oxide particles can be more effectively suppressed. Moreover, by making the silane coupling agent have a reactive group that can form a bond with a (meth) acrylate compound, the titanium oxide particles are firmly bonded to the (meth) acrylate contained in the high refractive index layer 16, and the scratch resistance of the anti-reflection film is improved. The silane coupling agent is usually bonded to the silicon atom in the molecule and has a hydrolyzable group and a functional group other than this. Here, the hydrolyzable group refers to a substituent that is directly bonded to the silicon atom and can produce a siloxane bond by a hydrolysis reaction and / or a condensation reaction. As a hydrolyzable group, for example, a halogen atom, an alkoxy group, an acyloxy group, and an alkenyloxy group can be listed. In the case where the hydrolyzable group has a carbon atom, the number of carbon atoms is preferably 6 or less, and more preferably 4 or less. Particularly preferred are alkoxy groups having no greater than 4 carbon atoms or alkenyloxy groups having no greater than 4 carbon atoms. The hydrolyzable group is hydrolyzed to form a bond with an oxygen atom on the surface of the titanium oxide particles, thereby surface-treating the titanium oxide particles.

[0059] The silane coupling agent used here contains, in addition to the above-mentioned hydrolyzable group, a reactive group that can form a bond with a (meth)acrylate compound. As the reactive group, carbon-carbon unsaturated double bond groups such as (meth)acryloyl, vinyl, styryl, and allyl, ring-opening polymerizable groups such as epoxy, and oxetanyl groups can be listed. These reactive groups are ultraviolet reactive. In the high refractive index layer 16 containing a (meth)acrylate compound having a reactive group and titanium oxide particles surface-treated by a silane coupling agent having a reactive group, the reactive group of the (meth)acrylate compound reacts with the reactive group of the silane coupling agent to form a bond.

[0060] Examples of the silane coupling agent having a carbon-carbon unsaturated double bond group as a reactive group include p-phenylvinyltrimethoxysilane, 2-(allyloxymethyl)acrylate (trimethoxysilyl)propyl, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, p-phenylvinyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and 7-octenyltrimethoxysilane.

[0061] Examples of the silane coupling agent having a ring-opening polymerizable group as a reactive group include 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 8-glycidoxyoctyltrimethoxysilane.

[0062] Among them, from the viewpoint of reactivity with (meth)acrylate compounds, silane coupling agents having a carbon-carbon unsaturated double bond group are preferred, and among them, silane coupling agents having an ethylenic carbon-carbon double bond group such as a (meth)acryloyl group, a vinyl group, a styryl group, and an allyl group are particularly preferred.

[0063] The content of the silane coupling agent is preferably set to a range of 1 part by mass or more and 40 parts by mass or less relative to 100 parts by mass of the titanium oxide particles. In this way, the effect of the surface treatment performed by the silane coupling agent is improved, and the scratch resistance and refractive index of the high refractive index layer 16 can be maintained at a high level. More preferably, the content is 5 parts by mass or more and 30 parts by mass or less. In the high refractive index layer 16, silane coupling agents that are not bonded to the titanium oxide particles may remain, and the preferred content range described here refers to the content of the silane coupling agent as a whole, including these silane coupling agents that are not bonded to the titanium oxide particles.

[0064] In addition, in titanium oxide particles, in order to more effectively suppress the photocatalytic activity, after the particle surface is coated with an inorganic compound other than a silane coupling agent, the surface treatment can be performed by a silane coupling agent, or a heterogeneous metal can be dissolved in the interior of the titanium oxide crystal. As inorganic compounds for coating, for example, oxides or hydroxides of zinc, cerium, iron, silicon, zirconium, and aluminum can be listed. As heterogeneous metals dissolved in the interior of the crystal, for example, tin, cobalt, vanadium, chromium, manganese, copper, antimony, tungsten, platinum, mercury, lead, bismuth, etc. can be listed. Among them, it is preferred to coat the surface of the titanium oxide particles with an oxide or hydroxide of aluminum.

[0065] The high refractive index layer 16 may also contain a dispersant. The dispersant helps maintain the state in which the titanium oxide particles are dispersed in the high refractive index layer forming composition (stabilizes the state). In addition, the surface of the high refractive index layer 16 after formation can be smoothed, so that the scratch resistance or transparency of the anti-reflection film is good.

[0066] The type of dispersant is not particularly limited. For example, coupling agents such as silane, titanate, and zircoaluminate, organic metal compounds such as metal chelates and metal alkoxides, surfactants such as polyoxyethylene alkyl phosphates and polyester acid salts, or commercially available resin dispersants may be added.

[0067] The content of the dispersant is preferably in the range of 15 parts by mass or more and 75 parts by mass or less, and more preferably 20 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the silane coupling agent.

[0068] The total amount of the silane coupling agent and the dispersant is preferably set to a range of 10 or more and 40 or more parts by mass relative to 100 parts by mass of the titanium oxide particles. When the total content of the silane coupling agent and the dispersant is 10 or more parts by mass, the effect brought by the addition of the above-mentioned silane coupling agent and the dispersant can be good. On the other hand, by suppressing the content to less than 40 parts by mass, it is possible to suppress the state in which the scratch resistance of the high refractive index layer 16 is reduced or the refractive index is reduced and it is difficult to obtain a good anti-reflection effect. From this viewpoint, the content is more preferably 15 or more and 35 or less parts by mass, and more preferably 15 or more and 30 or less parts by mass.

[0069] The average particle size (D50) based on volume of titanium oxide particles is more than 20nm. When D50 is less than 20nm, the dispersibility of the particles in the high refractive index layer 16 deteriorates. In this case, in order to improve the dispersibility of titanium oxide particles, for example, a large amount of dispersants need to be added to the composition. As a result, the titanium oxide content in the high refractive index layer 16 cannot be sufficient, the scratch resistance of the high refractive index layer 16 is reduced, or the refractive index is reduced and it is difficult to obtain a good anti-reflection effect. From the viewpoint of suppressing this phenomenon, D50 is set to more than 20nm, preferably more than 25nm, more preferably more than 30nm, and particularly preferably more than 34nm. In addition, in this specification, parameters related to particle size such as D10, D50, D90 represent values ​​in the cumulative particle size distribution based on volume. The cumulative particle size distribution based on volume can be obtained by dynamic light scattering. In addition, the particle size not only includes a primary particle size, but also includes a secondary particle size as an agglomerate of particles.

[0070] The upper limit of the volume-based average particle size (D50) of the titanium oxide particles is not particularly limited, but is preferably 100 nm or less. In this way, it is easy to make the cumulative 90% particle size (D90) based on the volume described later become 120 nm or less, and as a result, it is easy to suppress the situation where the surface smoothness decreases due to the particle size becoming too large than the film thickness of the high refractive index layer 16, and the scratch resistance or transparency of the anti-reflection film decreases. From this viewpoint, D50 is more preferably 80 nm or less, and more preferably 60 nm or less.

[0071] The cumulative 90% particle size (D90) of the titanium oxide particles based on volume is 120 nm or less. When D90 exceeds 120 nm, there is a possibility that the titanium oxide particles with large particle size form unevenness on the surface of the high refractive index layer 16, thereby reducing the smoothness and reducing the scratch resistance or transparency of the anti-reflection film. From the viewpoint of suppressing this phenomenon, D90 is set to 120 nm or less, preferably 110 nm or less, and more preferably 100 nm or less.

[0072] On the other hand, the lower limit of the cumulative 90% particle size (D90) based on the volume of the titanium oxide particles is not particularly limited, but is preferably 50 nm or more. If D90 is 50 nm or more, it is easy to control D50 to 20 nm or more, and it is easy to make the scratch resistance or anti-reflection property of the high refractive index layer 16 good. From this point of view, D90 is more preferably 55 nm or more, and more preferably 60 nm or more.

[0073] The cumulative 10% particle size (D10) of the titanium oxide particles based on volume is not particularly limited, but is preferably in the range of 10 nm or more and 40 nm or less. If D10 is in this range, the dispersibility of the titanium oxide particles becomes higher because there are fewer extremely small particles. In this way, it is easy to disperse the titanium oxide particles without a large amount of dispersant, and it is easy to make the titanium oxide content in the high refractive index layer 16 sufficient to obtain good scratch resistance or anti-reflection properties. From this point of view, D10 is more preferably 12 nm or more, and more preferably 15 nm or more. In addition, it is more preferably 35 nm or less, and more preferably 30 nm or less.

[0074] The PDI representing the particle size distribution width of the titanium oxide particles is preferably 4.0 or less. Here, PDI is a polydispersity index represented by (D90-D10) / D50, and the smaller the value, the more consistent the particle size. When the PDI is 4.0 or less, since the particle size of the titanium oxide is consistent, it is easy to obtain smoothness on the surface of the high refractive index layer 16. From this viewpoint, the PDI is preferably 3.0 or less, and more preferably 2.5 or less. The lower limit of the PDI is not particularly limited, but is usually 1.5 or more, or 2.0 or more.

[0075] The high refractive index layer 16 may contain inorganic oxide particles other than titanium oxide in addition to the titanium oxide particles.

[0076] As inorganic oxide particles other than titanium oxide, metal oxide particles including oxides of metals such as zirconium, silicon, aluminum, calcium, iron, copper, zinc, yttrium, niobium, molybdenum, indium, tin, tantalum, tungsten, lead, bismuth, cerium, and antimony can be listed. Among them, from the viewpoint of high refractive index or prevention of coloration, zirconium oxide, zinc oxide, niobium oxide, indium oxide, tin oxide, tungsten oxide, and antimony oxide particles are preferred. They can be used alone as inorganic oxide particles, or two or more can be used in combination. In order to prevent the inorganic oxide particles other than titanium oxide from significantly damaging the characteristics of titanium oxide particles in the high refractive index layer 16 such as high refractive index or improved scratch resistance, it is preferred that the inorganic oxide particles other than titanium oxide have the same particle size distribution (D50, D90, D 10, PDI) as the preferred examples listed above for titanium oxide particles and the content in the high refractive index layer 16 is suppressed to be less than that of titanium oxide particles. The inorganic oxide particles other than titanium oxide can also be surface-treated by a silane coupling agent.

[0077] When adding titanium oxide particles surface-treated by a silane coupling agent to the composition for forming the high refractive index layer 16, it is preferred that the titanium oxide particles surface-treated are dispersed in a solvent to form a particle dispersion, and then mixed with the composition for forming the high refractive index layer. In this case, in addition to the titanium oxide particles surface-treated by a silane coupling agent, the particle dispersion may also include a silane coupling agent, an inorganic compound, a dispersant, and other inorganic oxide particles that are not bonded to the titanium oxide particles. By pre-preparing the titanium oxide particles surface-treated with a (meth)acrylate compound before mixing, the titanium oxide particles surface-treated can be more efficiently dispersed in the composition for forming the high refractive index layer.

[0078] In the particle dispersion mixed with the composition for forming a high refractive index layer, the content of titanium atoms is preferably 35% by mass or more relative to the total 100% by mass of the solid component. If the content of titanium atoms is 35% by mass or more, the amount of titanium oxide contained in the high refractive index layer 16 can be increased, and the refractive index of the high refractive index layer 16 can be increased. From this viewpoint, the content of titanium atoms is more preferably 40% by mass or more, and more preferably 45% by mass or more. On the other hand, the content of titanium atoms is preferably 80% by mass or less relative to the total 100% by mass of the solid component. If the content of titanium atoms is 80% by mass or less, the content of silane coupling agent or dispersant can be fully increased, and a good particle dispersion can be obtained. From this viewpoint, the content of titanium atoms is more preferably 70% by mass or less, and more preferably 60% by mass or less. In addition, if a particle dispersion in which the content of titanium atoms is in the range listed here is used, the content of titanium oxide particles in the high refractive index layer 16 as a whole is easily contained in the appropriate range described below. In the particle dispersion, the content of titanium atoms in the solid component can be evaluated by measuring the element content using an energy dispersive X-ray analyzer.

[0079] In the particle dispersion, the solvent used as the dispersion medium for dispersing the titanium oxide particles includes, for example, alcohol solvents such as methanol, ethanol, isopropanol, ethylene glycol monomethyl ether (EGM), propylene glycol monomethyl ether (PGM), and diethylene glycol monobutyl ether, or glycol ester solvents such as ethylene glycol monomethyl ether acetate (EGMEA) and propylene glycol monomethyl ether acetate (PGMEA), ketone solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, and acetone, aromatic solvents such as toluene and xylene, and amide solvents such as N-methylpyrrolidone, acetamide, and dimethylformamide. As the solvent, one kind may be used alone, or two or more kinds may be used in combination.

[0080] The content of titanium oxide particles in the high refractive index layer 16 as a whole is preferably 45% by mass or more and 80% by mass or less relative to 100% by mass of the solid content of the high refractive index layer 16. When the content of titanium oxide particles in the high refractive index layer 16 is 45% by mass or more relative to 100% by mass of the solid content of the high refractive index layer 16, the refractive index of the high refractive index layer 16 can be increased to make the anti-reflection property good. In addition, from this viewpoint, the content of titanium oxide particles in the high refractive index layer 16 is more preferably 55% by mass or more relative to 100% by mass of the solid content of the high refractive index layer 16, and more preferably 60% by mass or more. And, when the content of titanium oxide particles in the high refractive index layer 16 is 80% by mass or less relative to 100% by mass of the solid content of the high refractive index layer 16, the reduction of scratch resistance is suppressed. In addition, from this viewpoint, the content of titanium oxide particles in the high refractive index layer 16 is more preferably 75% by mass or less relative to 100% by mass of the solid content of the high refractive index layer 16, and more preferably 72% by mass or less. In addition, the solid content of the high refractive index layer 16 mentioned here refers to the components excluding the components that are not fixed in the high refractive index layer 16 and are liquid at room temperature. The solid content of the high refractive index layer 16 includes titanium oxide particles, (meth) acrylate compounds, silane coupling agents, dispersants, inorganic oxide particles other than titanium oxide, etc. Solvents, etc. are not included.

[0081] The refractive index of the high refractive index layer 16 is not particularly limited as long as it is higher than the hard coating layer 14 and the low refractive index layer 18, and is preferably 1.83 or more and 2.00 or less at a wavelength of 550nm. When the refractive index is above 1.83, the anti-reflection film 10 can be made low-reflective without extremely reducing the refractive index of the low refractive index layer 18 described later. In this case, by setting the composition of the low refractive index layer 18 to a composition that is not extremely low in refractive index but shows high scratch resistance, the anti-reflection film 10 can have good scratch resistance. The refractive index of the high refractive index layer 16 is more preferably 1.85 or more, and more preferably 1.87 or more. On the other hand, when the refractive index of the high refractive index layer 16 is below 2.00, since it is not necessary to make the high refractive index layer 16 contain a large amount of titanium oxide particles, it is possible to suppress the falling off of titanium oxide particles from the high refractive index layer 16, and obtain good scratch resistance. From the above viewpoint, the refractive index of the high refractive index layer 16 is more preferably 1.98 or less, and more preferably 1.95 or less. In this specification, unless otherwise specified, the refractive index of a substance or a substance layer is taken as a value at a wavelength of 550 nm.

[0082] The thickness of high refractive index layer 16 is preferably in the range of more than 40nm and less than 120nm. When within this range, a good low visual sensitivity reflectivity can be obtained from the light interference effect produced at the interface with other layers, and the reflection of light can be alleviated. From this viewpoint, the thickness of high refractive index layer 16 is preferably more than 50nm, more preferably more than 60nm. In addition, it is preferably less than 100nm, more preferably less than 80nm.

[0083] The arithmetic mean roughness Sa of the surface of the high refractive index layer 16 is preferably 0.3 nm or more and 10 nm or less from the viewpoint of scratch resistance. More preferably, Sa is 0.4 nm or more, and further preferably 0.5 nm or more. In addition, more preferably, Sa is 7 nm or less, and further preferably 3 nm or less.

[0084] The high refractive index layer 16 can be formed using a composition comprising a (meth)acrylate compound having a reactive group and titanium oxide particles surface-treated by a silane coupling agent having a reactive group. As described above, the surface-treated titanium oxide particles are preferably added to the composition in the form of a particle dispersion. In the high refractive index layer 16, after irradiation with ionizing radiation, bonds are formed via reactive groups between the (meth)acrylate compounds, between the surface-treated titanium oxide particles, and between the (meth)acrylate compounds and the surface-treated titanium oxide particles, so that the high refractive index layer 16 has high scratch resistance. As described above, the reactive groups contained in the (meth)acrylate compound and the silane coupling agent are preferably ultraviolet reactive. When the (meth)acrylate compound and the titanium oxide particles have ultraviolet reactive reactive groups, by ultraviolet irradiation of the high refractive index layer 16 formed by the composition comprising the (meth)acrylate compound and the surface-treated titanium oxide particles, a high refractive index layer 16 with high scratch resistance is formed, and the scratch resistance of the anti-reflection film 10 is improved.

[0085] The high refractive index layer 16 may contain additives as necessary. Examples of such additives include antifouling agents, leveling agents, defoaming agents, thixotropic agents, antibacterial agents, flame retardants, slip agents, and refractive index adjusters.

[0086] In addition, the composition for forming the high refractive index layer 16 preferably contains a photopolymerization initiator when the (meth) acrylate compound contains a substance having a reactive group reactive to ultraviolet light (in the case of an ultraviolet curable resin). Furthermore, the composition for forming the high refractive index layer 16 may also contain a solvent (a solvent added separately independently of the solvent used as a dispersion medium in the particle dispersion of titanium oxide particles) as required. The (meth) acrylate compound of the high refractive index layer 16 may be composed of an ultraviolet curable resin, may be composed of a non-ultraviolet curable resin, or may be composed of a combination of an ultraviolet curable resin and a non-ultraviolet curable resin.

[0087] As non-ultraviolet curable resins, thermoplastic resins, thermosetting resins, etc. can be listed. As thermoplastic resins, polyester resins, polyether resins, polyolefin resins, polyamide resins, etc. can be listed. As thermosetting resins, unsaturated polyester resins, epoxy resins, alkyd resins, phenolic resins, etc. can be listed.

[0088] Examples of the photopolymerization initiator include alkylphenone-based, acylphosphine oxide-based, and oxime ester-based photopolymerization initiators. Examples of the alkylphenone-based photopolymerization initiator include 2,2'-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1 -ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2-benzylmethyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-morpholinophenyl)-1-butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, N,N-dimethylaminoacetophenone, etc. Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide. Examples of the oxime ester photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), etc. The photopolymerization initiator may be used alone or in combination of two or more.

[0089] The content of the photopolymerization initiator is preferably in the range of 0.1% by mass or more and 10% by mass or less based on the total solid content of the composition for forming the high refractive index layer 16 , and more preferably 1% by mass or more and 5% by mass or less.

[0090] As the solvent used in the composition for forming the high refractive index layer 16, the same solvent as the solvent used as the dispersion medium in the particle dispersion of the titanium oxide particles listed above can be used, and examples thereof include: alcohol solvents such as ethylene glycol monomethyl ether (EGM), propylene glycol monomethyl ether (PGM), and diethylene glycol monobutyl ether; ketone solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, and acetone; aromatic solvents such as toluene and xylene; amide solvents such as N-methylpyrrolidone, acetamide, and dimethylformamide, etc. These solvents can be used alone or in combination of two or more.

[0091] (Low refractive index layer)

[0092] In the anti-reflection film 10 according to the present embodiment, a low refractive index layer 18 is provided as an anti-reflection layer on the surface of the high refractive index layer 16. The low refractive index layer 18 has a lower refractive index than the hard coating layer 14 and the high refractive index layer 16, and exhibits an anti-reflection effect by an intentional refractive index difference with the hard coating layer 14 and the high refractive index layer 16.

[0093] The composition of the low refractive index layer 18 is not particularly limited, but preferably contains inorganic oxide particles, hollow silica particles, a fluorine-containing compound, and a binder resin. As the low refractive index layer 18, for example, the low refractive index layer described in International Publication No. 2021 / 020504 can be appropriately applied.

[0094] As the binder resin, a cured product of a thermosetting compound or a cured product of an ultraviolet curable compound is preferred from the viewpoint of improving the scratch resistance of the low refractive index layer 18. In addition, a cured product of an ultraviolet curable compound is more preferred from the viewpoint of productivity.

[0095] As ultraviolet curable resin, monomers, oligomers, prepolymers, etc. having ultraviolet reactive reactive groups can be listed. As ultraviolet reactive reactive groups, free radical polymerizable reactive groups having ethylenically unsaturated bonds such as acryloyl, methacryloyl, allyl, vinyl, and cationic polymerizable reactive groups such as oxetane can be listed. Among them, acryloyl, methacryloyl, and oxetane are more preferred, and acryloyl and methacryloyl are particularly preferred. That is, (meth)acrylate is particularly preferably used.

[0096] Examples of (meth)acrylates include urethane (meth)acrylates, silicone (meth)acrylates, alkyl (meth)acrylates, and aryl (meth)acrylates. (Meth)acrylates may be composed of monofunctional (meth)acrylates alone, polyfunctional (meth)acrylates, or a combination of monofunctional (meth)acrylates and polyfunctional (meth)acrylates. (Meth)acrylates preferably contain polyfunctional (meth)acrylates.

[0097] Examples of the monofunctional (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, , nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecyl (meth) acrylate, dimethicone Cyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 1-naphthylmethyl (meth)acrylate, 2-naphthylmethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxy-2-methylethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, 2-phenylphenoxyethyl (meth)acrylate, 4-phenylphenoxyethyl (meth)acrylate, 3-(2-phenylphenyl) ...3-(2-phenylphenyl)-2-hydroxypropyl (meth)acrylate, 3- )-2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and the like.

[0098] Examples of the polyfunctional (meth)acrylate include difunctional (meth)acrylate, trifunctional (meth)acrylate, and tetrafunctional (meth)acrylate. More specifically, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol tetra(meth)acrylate, tripentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, etc. can be mentioned.

[0099] The ultraviolet curable resin may be composed of one of the above-mentioned (meth)acrylates alone, or may be composed of two or more thereof. From the viewpoint of improving scratch resistance, the ultraviolet curable resin preferably comprises a polyfunctional (meth)acrylate having five or more functions, and it is preferred to increase the content of the polyfunctional (meth)acrylate having five or more functions.

[0100] In addition, it is preferred that the multifunctional (meth)acrylate contains a dimer. The dimer of the multifunctional (meth)acrylate can easily improve the curing rate of the curable composition due to its excellent curing speed, and thus can further improve the scratch resistance. Among them, it is preferred to include at least one selected from the group of dimers including pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate, and more preferably include at least one selected from the group of dimers including pentaerythritol triacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate.

[0101] From the viewpoint of scratch resistance, transparency, and solubility in solvents, the content of the dimer is preferably in the range of 25% by mass or more and 50% by mass or less based on the total solid content of the multifunctional (meth)acrylate, and more preferably 30% by mass or more and 40% by mass or less.

[0102] By including the inorganic oxide particles in the low refractive index layer 18, convex portions are formed on the surface of the low refractive index layer 18. By forming convex portions on the surface of the low refractive index layer 18 by the inorganic oxide particles, the low refractive index layer 18 can have good scratch resistance.

[0103] The inorganic oxide particles may be solid particles or hollow particles. The inorganic oxide particles are preferably solid particles. Solid particles refer to particles that do not substantially have a cavity inside the particles, and are particles in which the proportion of the cavity is less than 5% of the volume of the solid particles. Hollow particles refer to particles that have a cavity inside the particles, and are particles in which the proportion of the cavity is more than 5% of the volume of the hollow particles. When the inorganic oxide particles are solid particles, the scratch resistance of the low refractive index layer 18 is improved, and the scratch resistance of the anti-reflection film 10 is improved. When the inorganic oxide particles are hollow particles, the refractive index of the low refractive index layer 18 can be lowered to reduce the reflection of light. In the hollow particles, the proportion of the cavity is preferably more than 10% and less than 80% of the volume of the hollow particles. When the proportion of the cavity is more than 10%, the refractive index can be reduced and the reflection of light can be reduced. It is more preferably more than 20%, and more preferably more than 30%. On the other hand, when the proportion of the cavity is less than 80%, the decline in the dispersibility of the inorganic oxide particles can be suppressed. More preferably, it is 60% or less.

[0104] As the inorganic oxide particles, metal oxide particles including oxides of metals such as zirconium, silicon, aluminum, and calcium can be cited. As the inorganic oxide particles, one kind can be used alone, or two or more kinds can be used in combination. Among them, from the viewpoints of low refractive index, excellent transparency, high hardness, etc., silicon dioxide particles and aluminum oxide particles are preferred, and aluminum oxide particles are particularly preferred.

[0105] The shape of the inorganic oxide particles is not particularly limited, and may be spherical, needle-shaped, scaly, rod-shaped, fibrous, amorphous, etc. Among them, spherical is preferred.

[0106] In order to form a convex portion on the surface of the low refractive index layer 18 with the inorganic oxide particles, a good scratch resistance is obtained, and the difference (rd) between the average particle size r of the inorganic oxide particles and the average thickness d of the low refractive index layer 18 can be 10 nm or more. The difference (rd) is more preferably 15 nm or more, and more preferably 18 nm or more. On the other hand, from the viewpoints of suppressing the height of the formed convex portion and maintaining transparency, the difference (rd) is 300 nm or less. It is more preferably 200 nm or less, and more preferably 100 nm or less.

[0107] The average particle size r of the inorganic oxide particles is preferably within the range of 60 nm or more and 400 nm or less, although it also depends on the average thickness d of the low refractive index layer 18. It is more preferably 70 nm or more, and more preferably 90 nm or more. In addition, it is more preferably 300 nm or less, and more preferably 200 nm or less. The average particle size r of the inorganic oxide particles is the arithmetic mean value based on volume obtained by following the laser diffraction / scattering method of JIS Z8825, and includes not only the primary particle size, but also the secondary particle size of the agglomerate of the particles.

[0108] The content of the inorganic oxide particles in the low refractive index layer 18 can be 0.1% by mass or more and 4.0% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 18. When the content of the inorganic oxide particles in the low refractive index layer 18 is 0.1% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 18, excellent scratch resistance can be obtained. In addition, from this viewpoint, the content of the inorganic oxide particles in the low refractive index layer 18 is more preferably 0.5% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 18, and more preferably 1.0% by mass or more. And, when the content of the inorganic oxide particles in the low refractive index layer 18 is 4.0% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 18, high transparency can be obtained. In addition, from this viewpoint, the content of the inorganic oxide particles in the low refractive index layer 18 is more preferably 3.5% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 18, and more preferably 3.2% by mass or less. In addition, the solid component of the low refractive index layer 18 mentioned here refers to the components excluding the components that are liquid at room temperature and are not fixed by the binder resin in the low refractive index layer 18. As the solid component of the low refractive index layer 18, inorganic oxide particles, hollow silica particles, binder resin, fluorine-containing compounds fixed by the binder resin, etc. are included. Oil components as additives, surfactants that are not fixed by the binder resin, etc. are not included.

[0109] Hollow silica particles are particles whose average particle size is smaller than the average thickness of the low refractive index layer 18. Hollow silica particles can be particles whose average particle size is smaller than the average particle size of inorganic oxide particles that form convex portions on the surface of the low refractive index layer 18. Hollow silica particles are particles that do not substantially contribute to the formation of surface convexities of the low refractive index layer 18. Hollow silica particles refer to particles having cavities inside the particles, and are particles whose proportion of cavities is more than 5% of the volume. Hollow refers to a shell structure composed of an outer shell and a cavity inside it, or a porous structure with many cavities. Since the hollow silica particles are hollow structures, the refractive index of the low refractive index layer 18 can be lowered, reducing the reflection of light. The shape of the hollow silica particles is not particularly limited, but preferably spherical, spindle-shaped, egg-shaped, flat, cubic, amorphous, etc. Among them, spherical, flat, cubic, etc. are particularly preferred.

[0110] In the hollow silica particles, the proportion of the cavity is preferably 10% or more and 80% or less by volume. When the proportion of the cavity is 10% or more by volume, the refractive index can be lowered and the reflection of light can be reduced. It is more preferably 20% or more by volume, and further preferably 30% or more by volume. On the other hand, when the proportion of the cavity is 80% or less by volume, the decrease in the dispersibility of the hollow silica particles can be suppressed. It is more preferably 60% or less by volume.

[0111] The average particle size of hollow silica particles is preferably more than 5nm and less than 100nm, although it also depends on the average thickness of low refractive index layer 18. More preferably more than 20nm, more preferably more than 40nm. In addition, more preferably less than 80nm, more preferably less than 70nm. When the average particle size of hollow silica particles is within these preferred ranges, excellent anti-reflection effect and transparency can be obtained in low refractive index layer 18. The average particle size is the arithmetic mean value based on volume obtained by following the laser diffraction / scattering method of JIS Z8825. Not only a primary particle size is included, but also a secondary particle size as an agglomerate of particles.

[0112] The refractive index of the hollow silica particles is preferably within a range of 1.01 to 1.45. More preferably, it is within a range of 1.15 to 1.38, and further preferably, it is within a range of 1.15 to 1.35. When the refractive index of the hollow silica particles is within this range, an excellent anti-reflection effect can be obtained.

[0113] The content of the hollow silica particles in the low refractive index layer 18 can be 6.0% by mass or more and 49.9% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 18. When the content of the hollow silica particles in the low refractive index layer 18 is 6.0% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 18, excellent anti-reflection properties can be obtained. In addition, from this viewpoint, the content of the hollow silica particles in the low refractive index layer 18 is more preferably 10% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 18, further preferably 20% by mass or more, and particularly preferably 30% by mass or more. In addition, when the content of the hollow silica particles in the low refractive index layer 18 is 49.9% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 18, the decrease in scratch resistance is suppressed. From this viewpoint, the content of the hollow silica particles in the low refractive index layer 18 is more preferably 45% by mass or less, and further preferably 40% by mass or less, based on 100% by mass of the solid content of the low refractive index layer 18 .

[0114] And, the total amount of the inorganic oxide particles and hollow silica particles in the low refractive index layer 18 can be 10% by mass or more and 50% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 18. When the total amount of the inorganic oxide particles and hollow silica particles in the low refractive index layer 18 is 10% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 18, excellent scratch resistance can be obtained. In addition, from this viewpoint, the total amount of the inorganic oxide particles and hollow silica particles in the low refractive index layer 18 is more preferably 20% by mass or more, and further preferably 30% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 18. On the other hand, when the total amount of the inorganic oxide particles and hollow silica particles in the low refractive index layer 18 is 50% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 18, the inorganic oxide particles and hollow silica particles can be sufficiently maintained in the low refractive index layer 18, so excellent scratch resistance can be obtained. In addition, from this viewpoint, the total amount of the inorganic oxide particles and the hollow silica particles in the low refractive index layer 18 is more preferably 48 mass % or less, further preferably 46 mass % or less, and particularly preferably 43 mass % or less, relative to 100 mass % of the solid content of the low refractive index layer 18.

[0115] In the low refractive index layer 18, the fluorine-containing compound can function as an antifouling agent. In addition, the smoothness of the surface of the low refractive index layer 18 is improved, so it can contribute to the improvement of scratch resistance. As fluorine-containing compounds, (meth) acrylates containing perfluoroalkyl groups can be listed. As such compounds, "KY-1203" manufactured by Shin-Etsu Chemical, "MEGAFAC RS-75" manufactured by DIC, "OPTOOL DAC-HP" manufactured by Daikin Industries, "FTERGENT601AD" manufactured by Neos, etc. can be listed. By using such fluorine-containing compounds, the adhesion of dirt or fingerprints can be suppressed, and dirt or fingerprints can be easily removed.

[0116] The content of the fluorinated compound in the low refractive index layer 18 is preferably 1.0 mass % or more and 15.0 mass % or less relative to the solid content 100 mass % of the low refractive index layer 18. When the content of the fluorinated compound in the low refractive index layer 18 is 1.0 mass % or more relative to the solid content 100 mass % of the low refractive index layer 18, the smoothness of the surface of the low refractive index layer 18 is improved, and the scratch resistance is improved. In addition, antifouling property is improved. And, from this viewpoint, the content of the fluorinated compound in the low refractive index layer 18 is more preferably 2.0 mass % or more relative to the solid content 100 mass % of the low refractive index layer 18, and further preferably 3.0 mass % or more. And, when the content of the fluorinated compound in the low refractive index layer 18 is 15.0 mass % or less relative to the solid content 100 mass % of the low refractive index layer 18, the decline of scratch resistance is suppressed. From this viewpoint, the content of the fluorine-containing compound in the low refractive index layer 18 is more preferably 13.0 mass % or less, further preferably 10.0 mass % or less, and particularly preferably 5.0 mass % or less, based on 100 mass % of the solid content of the low refractive index layer 18 .

[0117] The refractive index of low refractive index layer 18 is not particularly limited as long as it is lower than hard coat 14 and high refractive index layer 16, but is preferably more than 1.35 and less than 1.49. When the refractive index is more than 1.35, the intensity of low refractive index layer 18 can be enough, and good scratch resistance can be obtained. On the other hand, when the refractive index is less than 1.49, the further low reflectivity of anti-reflection film can be made. From the above viewpoint, the refractive index of low refractive index layer 18 is more preferably more than 1.38 and less than 1.46, more preferably more than 1.40 and less than 1.44.

[0118] The thickness of low refractive index layer 18 is preferably within the range of more than 80nm and less than 110nm. More preferably, it is more than 85nm, and more preferably, it is more than 90nm. In addition, it is more preferably less than 105nm, and more preferably less than 100nm. When within this range, good low visual sensitivity reflectivity can be obtained, and the reflection of light can be alleviated.

[0119] The low refractive index layer 18 can be formed using a composition comprising inorganic oxide particles, hollow silica particles, a fluorine-containing compound and a binder resin. The fluorine-containing compound and the binder resin preferably have a reactive group reactive to ultraviolet light. As the reactive group reactive to ultraviolet light, (meth) acryloyl and the like can be cited. When the fluorine-containing compound and the binder resin have a reactive group reactive to ultraviolet light, the scratch resistance of the low refractive index layer 18 is improved, and the scratch resistance of the anti-reflection film 10 is improved. In the case where the binder resin contains a substance having a reactive group reactive to ultraviolet light (ultraviolet curable resin), the composition for forming the low refractive index layer 18 preferably contains a photopolymerization initiator. In the composition for forming the low refractive index layer 18, a solvent may also be included as needed. The binder resin of the low refractive index layer 18 may be composed of an ultraviolet curable resin, may be composed of a non-ultraviolet curable resin, or may be composed of a combination of an ultraviolet curable resin and a non-ultraviolet curable resin.

[0120] As non-ultraviolet curable resins, thermoplastic resins, thermosetting resins, etc. can be listed. As thermoplastic resins, polyester resins, polyether resins, polyolefin resins, polyamide resins, etc. can be listed. As thermosetting resins, unsaturated polyester resins, epoxy resins, alkyd resins, phenolic resins, etc. can be listed.

[0121] Examples of the photopolymerization initiator include alkylphenone-based, acylphosphine oxide-based, and oxime ester-based photopolymerization initiators. Examples of the alkylphenone-based photopolymerization initiator include 2,2'-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1 -ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2-benzylmethyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-morpholinophenyl)-1-butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, N,N-dimethylaminoacetophenone, etc. Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide. Examples of the oxime ester photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), etc. The photopolymerization initiator may be used alone or in combination of two or more.

[0122] The content of the photopolymerization initiator is preferably in the range of 0.1% by mass or more and 10% by mass or less based on the total solid content of the composition for forming the low refractive index layer 18 , and more preferably 1% by mass or more and 5% by mass or less.

[0123] As the solvent used in the composition for forming the low refractive index layer 18, there can be listed: alcohol solvents such as ethylene glycol monomethyl ether (EGM), propylene glycol monomethyl ether (PGM), and diethylene glycol monobutyl ether; ketone solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, and acetone; aromatic solvents such as toluene and xylene; amide solvents such as N-methylpyrrolidone, acetamide, and dimethylformamide, etc. These solvents can be used alone or in combination of two or more.

[0124] Furthermore, additives may be included in the low refractive index layer 18 as necessary. Examples of such additives include antifouling agents, dispersants, leveling agents, defoaming agents, thixotropic agents, antibacterial agents, flame retardants, slip agents, and refractive index adjusters.

[0125] (Method for producing anti-reflection film)

[0126] When manufacturing the antireflection film 10, first, a composition for forming the hard coating layer 14 is applied on the surface of the base film 12, dried as required, and then cured by irradiation with ionizing radiation such as ultraviolet rays, thereby forming the hard coating layer 14 on the surface of the base film 12. Thereafter, a composition for forming the high refractive index layer 16 is applied on the surface of the hard coating layer 14, dried as required, and then cured by irradiation with ionizing radiation such as ultraviolet rays, thereby forming the high refractive index layer 16 on the surface of the hard coating layer 14. Furthermore, a composition for forming the low refractive index layer 18 is applied on the surface of the high refractive index layer 16, dried as required, and then cured by irradiation with ionizing radiation such as ultraviolet rays, thereby forming the low refractive index layer 18 on the surface of the high refractive index layer 16. Through these steps, the antireflection film 10 can be manufactured.

[0127] When the hard coating layer 14 is formed on the surface of the substrate film 12, the surface of the substrate film 12 may be subjected to a surface treatment before coating in order to improve the adhesion between the substrate film 12 and the hard coating layer 14. Examples of the surface treatment include corona treatment, plasma treatment, hot air treatment, ozone treatment, and ultraviolet treatment.

[0128] In the application of the composition for forming the hard coat layer 14, the composition for forming the high refractive index layer 16, and the composition for forming the low refractive index layer 18, for example, various coating methods such as reverse gravure coating, direct gravure coating, die coating, rod coating, wire bar coating, roll coating, spin coating, dip coating, spray coating, knife coating, kiss coating, or various printing methods such as inkjet, offset printing, screen printing, and flexographic printing can be used.

[0129] The drying step for each layer is not particularly limited as long as the solvent used in the coating liquid can be removed, but is preferably performed at a temperature of 50 to 150° C. for about 10 to 180 seconds.

[0130] In the ultraviolet irradiation for each layer, a high pressure mercury lamp, an electrodeless (microwave type) lamp, a xenon lamp, a metal halide lamp, or any other ultraviolet irradiation device can be used. If necessary, ultraviolet irradiation can also be performed under an inert gas atmosphere such as nitrogen. The ultraviolet irradiation amount is not particularly limited, but is preferably 50 to 800 mJ / cm 2 , more preferably 100 to 300 mJ / cm 2 .

[0131] (Properties of anti-reflection film)

[0132] The arithmetic mean roughness Sa of the surface of the antireflection film 10, i.e., the surface of the low refractive index layer 18, is preferably 1.0 nm or more and 20 nm or less from the viewpoint of good finger smoothness and scratch resistance. It is more preferably 3.0 nm or more, and further preferably 5.0 nm or more. In addition, it is more preferably 15 nm or less, and further preferably 10 nm or less.

[0133] From the viewpoint of good transparency and the like, the haze of the antireflection film 10 is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less.

[0134] The lower the visual reflectance of the antireflection film 10 , the better. It is preferably 0.5% or less, more preferably 0.4% or less, and even more preferably 0.3% or less.

[0135] The anti-reflection film 10 of the above structure has a substrate film 12, a hard coating layer 14 formed on the surface of the substrate film 12, a high refractive index layer 16 formed on the surface of the hard coating layer 14, and a low refractive index layer 18 formed on the surface of the high refractive index layer 16, wherein the high refractive index layer 16 is composed of a cured product of an ionizing radiation curable composition, wherein the ionizing radiation curable composition contains a (meth) acrylate compound having a reactive group and titanium oxide particles surface-treated by a silane coupling agent having a reactive group, wherein the titanium oxide particles have a volume-based average particle size (D50) of 20 nm or more and a volume-based cumulative 90% particle size (D90) of 120 nm or less, so it has high anti-reflection properties and excellent scratch resistance. The titanium oxide particles contained in the high refractive index layer 16 are surface-modified as described above and have a predetermined particle size distribution, which contributes to improving the anti-reflection properties and scratch resistance of the anti-reflection film 10. Furthermore, in Patent Document 1, although titanium oxide fine particles are contained in the high refractive index layer 16 , the presence or absence of surface modification and the particle size distribution of the titanium oxide fine particles are unclear.

[0136] <Other types of anti-reflection films>

[0137] The anti-reflection film according to the present invention is not limited to the configuration of the anti-reflection film 10 according to the first embodiment as long as the hard coating layer 14, the high refractive index layer 16 having a predetermined composition, and the low refractive index layer 18 are stacked in order on the surface of the base film 10 as described above. Other embodiments of the anti-reflection film according to the present invention are exemplified below.

[0138] (Second Embodiment)

[0139] Figure 22 shows an antireflection film 20 according to the second embodiment. The antireflection film 20 according to the second embodiment includes: a base film 12; a hard coating layer 14 formed on the surface of the base film 12; a medium refractive index layer 15 formed on the surface of the hard coating layer 14; a high refractive index layer 16 formed on the surface of the medium refractive index layer 15; and a low refractive index layer 18 formed on the surface of the high refractive index layer 16. That is, the antireflection film 20 includes the base film 12, the hard coating layer 14, the medium refractive index layer 15, the high refractive index layer 16, and the low refractive index layer 18 in this order from the base film 12 side.

[0140] The anti-reflection film 20 involved in the second embodiment is different from the anti-reflection film 10 involved in the first embodiment in that a medium refractive index layer 15 is provided between the hard coating layer 14 and the high refractive index layer 16. Other than this, it is the same as the anti-reflection film 10 involved in the first embodiment, and the description of the same structure is omitted.

[0141] The medium refractive index layer 15 is a layer for showing a higher antireflection effect by an intentional refractive index difference with the high refractive index layer 16 and an intentional refractive index difference with the low refractive index layer. The refractive index of the medium refractive index layer 15 is higher than that of the hard coat layer 14 and lower than that of the high refractive index layer 16. Further, it is preferably higher than that of the low refractive index layer 18.

[0142] The refractive index of the medium refractive index layer 15 is preferably within the range of 1.56 or more and 1.85 or less at a wavelength of 550 nm. It is more preferably 1.60 or more, and further preferably 1.65 or more. In addition, it is more preferably 1.80 or less, and further preferably 1.75 or less. When the refractive index of the medium refractive index layer 15 is within the above range, the balance of interference produced by the refractive index difference of the medium refractive index layer 15 and other layers can be made suitable, and a higher anti-reflection effect can be obtained.

[0143] The thickness of the medium refractive index layer 15 is preferably in the range of more than 30nm and less than 120nm. More preferably more than 50nm, more preferably more than 70nm. In addition, more preferably less than 100nm, more preferably less than 90nm. By setting the thickness of the medium refractive index layer 15 to the above range, the anti-reflection function can be further improved.

[0144] The constituent material of the medium refractive index layer 15 is not particularly limited, as long as the known material used for anti-reflection film etc. in the past can be used in a manner that can obtain a specified refractive index. For example, it is only necessary to appropriately select from the materials described above as the materials that can be used in the hard coat layer 14. In addition, it is also possible to appropriately select from the materials described above as the materials that can be used in the high refractive index layer 16. The refractive index of the medium refractive index layer 15 can be adjusted by the selection of binder resin, inorganic oxide particles, resin particles, and the mixing amount. For example, by making the content of inorganic oxide particles such as titanium oxide particles less than the high refractive index layer 16, a medium refractive index layer 15 having a refractive index lower than the high refractive index layer 16 can be formed.

[0145] (Third Embodiment)

[0146] Figure 3 3 shows an anti-reflection film 30 according to the third embodiment. The anti-reflection film 30 according to the third embodiment includes: a base film 12; a hard coating layer 14 formed on one surface of the base film 12; a high refractive index layer 16 formed on the surface of the hard coating layer 14; and a low refractive index layer 18 formed on the surface of the high refractive index layer 16. In addition, a transparent adhesive layer 22 is provided on the other surface of the base film 12. A release film 24 is disposed on the surface of the transparent adhesive layer 22 as required. The release film 24 functions as a protective layer of the transparent adhesive layer 22 before the anti-reflection film 30 is used, and is peeled off from the transparent adhesive layer 22 when the anti-reflection film 30 is used.

[0147] The anti-reflection film 30 involved in the third embodiment is different from the anti-reflection film 10 involved in the first embodiment in that a transparent adhesive layer 22 is provided on the other surface of the base film 12. Other than this, it is the same as the anti-reflection film 10 involved in the first embodiment, and the description of the same structure is omitted.

[0148] The transparent adhesive layer 22 is used to adhere the anti-reflection film 30 to the surface of a display or the like with good adhesion. In addition, the anti-reflection film 30 has an effect of preventing the glass of the display or the like from scattering by having the transparent adhesive layer 22. That is, the anti-reflection film 30 also functions as an anti-scattering film.

[0149] The adhesive composition forming the transparent adhesive layer 22 can contain known adhesive resins such as acrylic adhesives, silicone adhesives, and urethane adhesives. Among them, acrylic adhesives are preferred from the viewpoint of optical transparency or heat resistance. In order to improve the cohesive force of the transparent adhesive layer 22, it is preferred that the adhesive composition contains a crosslinking agent. As the crosslinking agent, isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, chelate crosslinking agents, etc. can be listed.

[0150] Adhesive composition can also include additives as required. As additives, known additives such as plasticizers, silane coupling agents, surfactants, antioxidants, fillers, curing accelerators, and curing retardants can be listed. In addition, from the viewpoints such as productivity, organic solvents can also be used for dilution.

[0151] The thickness of the transparent adhesive layer 22 is not particularly limited, but is preferably within a range of 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

[0152] The transparent adhesive layer 22 can be formed by the following methods, etc.: a method of directly applying an adhesive composition on the other side of the substrate film 12 to form a transparent adhesive layer; a method of applying an adhesive composition on the surface of a release film 24 to form a transparent adhesive layer and then transferring the transparent adhesive layer to the other side of the substrate film 12; and a method of applying an adhesive composition on the surface of a first release film to form a transparent adhesive layer, then laminating a second release film, peeling off either release film and transferring the transparent adhesive layer to the other side of the substrate film 12.

[0153] From the viewpoint of the effect of preventing glass scattering, the adhesive force of the transparent adhesive layer 22 to the glass is preferably 4 N / 25 mm or more, more preferably 6 N / 25 mm or more, and even more preferably 10 N / 25 mm or more.

[0154] (Fourth Embodiment)

[0155] Figure 4 4 shows an anti-reflection film 40 according to a fourth embodiment. The anti-reflection film 40 according to the fourth embodiment includes: a base film 12; a hard coating layer 14 formed on one surface of the base film 12; a high refractive index layer 16 formed on the surface of the hard coating layer 14; a low refractive index layer 18 formed on the surface of the high refractive index layer 16; and a protective film 28 disposed on the surface of the low refractive index layer 18 via an adhesive layer 26.

[0156] The anti-reflection film 40 involved in the fourth embodiment is different from the anti-reflection film 10 involved in the first embodiment in that a protective film 28 is provided on the surface of the low refractive index layer 18 via an adhesive layer 26. Other than this, it is the same as the anti-reflection film 10 involved in the first embodiment, and the description of the same structure is omitted.

[0157] The protective film 28 can prevent the surface of the low refractive index layer 18 from being damaged when the protective film 28 is continuously processed by a rolling process or attached to an anti-reflection film 40 such as a display. The protective film 28 is attached to the surface of the low refractive index layer 18 via the adhesive layer 26. After processing, the protective film 28 is peeled off from the surface of the low refractive index layer 18 together with the adhesive layer 26. Therefore, with respect to the adhesive layer 26, the adhesive force between the protective film 28 and the adhesive layer 26 is stronger than the adhesive force between the low refractive index layer 18 and the adhesive layer 26, and the adhesive force is adjusted so that the interface between the low refractive index layer 18 and the adhesive layer 26 can be peeled off.

[0158] The material constituting the protective film 28 can be appropriately selected from the materials exemplified as the material constituting the base film 12. The thickness of the protective film 28 is not particularly limited, but can be set within the range of 2 μm to 500 μm or within the range of 2 μm to 200 μm.

[0159] The adhesive forming the adhesive layer 26 is not particularly limited, and acrylic adhesives, silicone adhesives, urethane adhesives, etc. can be used appropriately. In particular, acrylic adhesives are suitable because of their excellent transparency or heat resistance. Preferably, the acrylic adhesive is formed from an adhesive composition containing a (meth)acrylic acid polymer and a crosslinking agent.

[0160] The (meth)acrylic polymer is a homopolymer or copolymer of a (meth)acrylic monomer. Examples of the (meth)acrylic monomer include an alkyl group-containing (meth)acrylic monomer, a carboxyl group-containing (meth)acrylic monomer, and a hydroxyl group-containing (meth)acrylic monomer.

[0161] Examples of the alkyl group-containing (meth)acrylic acid monomer include (meth)acrylic acid monomers having an alkyl group with 2 to 30 carbon atoms. The alkyl group with 2 to 30 carbon atoms may be linear, branched, or cyclic. More specifically, examples of the alkyl group-containing (meth)acrylic acid monomer include isostearyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, decyl (meth)acrylate, isononyl (meth)acrylate, nonyl (meth)acrylate, isooctyl (meth)acrylate, octyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, propyl (meth)acrylate, ethyl (meth)acrylate, and methyl (meth)acrylate.

[0162] Examples of the carboxyl group-containing (meth)acrylic acid monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, etc. The carboxyl group may be located at the end of the alkyl chain or in the middle of the alkyl chain.

[0163] Examples of the hydroxyl group-containing (meth)acrylic acid monomer include hydroxylauryl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, etc. The hydroxyl group may be located at the end of the alkyl chain or in the middle of the alkyl chain.

[0164] The (meth)acrylic monomer forming the (meth)acrylic polymer may be any one of the above-mentioned monomers, or may be a combination of two or more thereof.

[0165] Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, metal chelate crosslinking agents, metal alkoxide crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, and melamine crosslinking agents. The crosslinking agent may be used alone or in combination of two or more.

[0166] In the adhesive composition, in addition to comprising (meth) acrylic polymer and crosslinking agent, other additives may also be included. As other additives, crosslinking accelerators, crosslinking delay agents, resins (tackifiers) that impart adhesiveness, antistatic agents, silane coupling agents, plasticizers, stripping aids, pigments, dyes, wetting agents, thickeners, ultraviolet light absorbers, preservatives, antioxidants, metal deactivators, alkylating agents, flame retardants, etc. may be listed. These additives are appropriately selected for use according to the purpose or use purpose of the adhesive.

[0167] The thickness of the adhesive layer 26 is not particularly limited, but is preferably within a range of 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 7 μm or less.

[0168] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment at all, and various changes can be made within the scope not departing from the gist of the present invention.

[0169] For example, in the above-mentioned embodiment, it is described that the surface of the base film 12 can be subjected to a surface treatment. However, instead of the surface treatment, an easy-adhesion layer may be provided on the surface of the base film 12 .

[0170] Furthermore, in each of the above-described embodiments, an antifouling layer may be formed on the surface of the low-refractive index layer 18 in order to further improve the antifouling property.

[0171] When an antifouling layer is provided on the surface of the antireflection film 20, from the viewpoint of reducing the reflection at the interface, it is preferred that the refractive index difference between the low refractive index layer 18 and the antifouling layer is small. The refractive index of the antifouling layer is preferably less than 1.6, more preferably less than 1.55. As the material of the antifouling layer, fluorine-containing silane compounds or fluorine-containing organic compounds are preferred. The antifouling layer can be formed by wet methods such as reverse coating, die coating, gravure coating, or dry processes such as vacuum evaporation, CVD. The thickness of the antifouling layer is generally more than 1nm and less than about 50nm, preferably more than 2nm and less than 30nm, more preferably more than 3nm and less than 20nm. In addition, before forming the antifouling layer, surface treatment can also be implemented. As surface treatment, corona treatment, plasma treatment, hot air treatment, ozone treatment, ultraviolet treatment, etc. can be listed.

[0172] Furthermore, the transparent adhesive layer 22 and the release film 24 in the third embodiment are as follows: Figure 3 The following table shows the method to append to Figure 1 The antireflection film 10 of the first embodiment is shown in the form of a film, but it may also be added to Figure 2 The antireflection film 20 of the second embodiment is shown in FIG. In addition, the adhesive layer 26 and the protective film 28 in the fourth embodiment are as follows: Figure 4 The following table shows the method to append to Figure 1 The antireflection film 10 of the first embodiment is shown in the form of a film, but it may also be added to Figure 2 The antireflection film 20 of the second embodiment shown or Figure 3 The form of the antireflection film 30 of the third embodiment is shown.

[0173] Furthermore, various functional layers such as a gas barrier improving layer, an antistatic layer, and an oligomer block layer may be provided on the surface of the base film 12 before forming each layer.

[0174] The purpose of providing the antistatic layer is to reduce the adhesion of surrounding dust and the like due to peeling electrification or friction electrification, etc. The antistatic layer is preferably a layer composed of an antistatic layer-forming composition containing an antistatic agent.

[0175] As antistatic agents, for example, cationic antistatic agents such as quaternary ammonium salts and pyridinium salts, anionic antistatic agents such as alkali metal salts of sulfonic acid, phosphoric acid, carboxylic acid, etc., amphoteric antistatic agents such as amino acid series and amino acid sulfate series, nonionic antistatic agents such as amino alcohol series, glycerol series, polyethylene glycol series, ionic compounds, conductive polymers such as polyacetylene series and polythiophene series, conductive particles such as metal oxide particles or carbon nanotubes, conductive fibers, etc. Among them, antistatic agents, metal particles, and metal oxide particles formed by combining conductive polymers such as polyacetylene and polythiophene with dopants are preferred from the viewpoints of low humidity dependence and prevention of seepage from the antistatic layer.

[0176] As the conductive polymer constituting the antistatic agent, specifically, conductive polymers such as polyacetylene, polyaniline, polythiophene, polypyrrole, polyphenylene sulfide, poly(1,6-heptadiyne), polybiphenylene (polyparaphenylene), polyparaphenylene sulfide, polyphenylene vinylene, poly(2,5-thiophene) or derivatives thereof can be listed, and preferably, conductive organic polymers of polythiophene series (for example, 3,4-ethylenedioxythiophene (PEDOT) etc.) can be listed. As the antistatic agent, one kind can be used alone, or two or more kinds can be used in combination.

[0177] Based on the total solid content of the antistatic layer forming composition, the content of the antistatic agent is preferably set to a range of more than 1% by mass and less than 50% by mass. If the content is more than 1% by mass, good antistatic properties can be imparted. More preferably, more than 5% by mass, more preferably more than 10% by mass. On the other hand, if its content is less than 50% by mass, a highly transparent film with good total light transmittance can be obtained. More preferably, less than 40% by mass, more preferably less than 20% by mass.

[0178] The antistatic layer may also contain a binder resin. The binder resin is not particularly limited as long as it is compatible with or can be mixed and dispersed with the antistatic agent, and may be a curable resin or a thermoplastic resin.

[0179] Examples of thermoplastic resins include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyimide resins such as polyimide and polyamideimide; polyamide resins such as polyamide 6, polyamide 6,6, polyamide 12, and polyamide 11; polyvinylidene fluoride; acrylic resins; vinyl resins such as polyvinyl alcohol; and urethane resins.

[0180] As the curable resin, the same material as that used when forming the hard coat layer 14 can be used.

[0181] The thickness of the antistatic layer is preferably 1 nm or more and 5 μm or less from the viewpoint of antistatic properties, more preferably 10 nm or more, and further preferably 30 nm or more, and more preferably 1 μm or less, and further preferably 300 nm or less.

[0182] Example

[0183] Hereinafter, the present invention will be described in detail using Examples and Comparative Examples. Unless otherwise specified, the preparation and evaluation of samples were performed at room temperature in the atmosphere.

[0184] <Preparation of hard coat layer forming composition>

[0185] To the ultraviolet curable composition "LUXYDIR ESS-620" (manufactured by DIC, urethane acrylate resin, solvent: ethyl acetate, solid content concentration: 79% by mass) was added a photopolymerization initiator "Omnirad127" (manufactured by IGM Resins BV, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propane-1-one) in an amount of 3% by mass relative to the total amount of the hard coat layer forming composition, and ethyl acetate was further added so that the solid content concentration became 45% by mass to prepare a hard coat layer forming composition.

[0186] <Preparation of Composition for Forming Medium Refractive Index Layer>

[0187] The components were mixed so that the concentration of the ultraviolet curable resin in the total solid content was 46 mass %, the titanium oxide particle dispersion was 55 mass %, and the photopolymerization initiator was 4 mass %, and the solid content concentration was adjusted to 3.9 mass % using a solvent (PGM) to prepare a composition for forming a medium refractive index layer.

[0188] The materials used as the constituent components of the composition for forming a medium refractive index layer are as follows.

[0189] · Ultraviolet curable resin: "Aronix MT-3041" manufactured by Toa Gosei Co., Ltd., multifunctional acrylate, solid content concentration: 100% by mass

[0190] Titanium oxide particle dispersion 1 - "LDB-102-45" manufactured by Ishihara Sangyo, containing titanium oxide particles surface-treated with a silane coupling agent having a methacryloyl group and a dispersant, solvent: propylene glycol monomethyl ether (PGM), solid content concentration: 45% by mass

[0191] Photopolymerization initiator - the above-mentioned "Omnirad 127"

[0192] <Preparation of high refractive index layer-forming composition>

[0193] Each component was mixed so as to have the compounding composition shown in Table 2 (unit: mass % in the total solid content), and PGM was further added so as to have the solid content concentration shown in Table 2 to prepare a composition for forming a high refractive index layer.

[0194] The materials used as the constituent components of the composition for forming a high refractive index layer are as follows.

[0195] The titanium oxide particles are all rutile.

[0196] ·Ultraviolet curable resin - the above-mentioned "Aronix MT-3041"

[0197] Titanium oxide particle dispersion 1 - the above-mentioned "LDB-102-45"

[0198] Titanium oxide particle dispersion 2 - "LDB-102H-35" manufactured by Ishihara Sangyo, containing titanium oxide particles surface-treated with a silane coupling agent having a methacryloyl group and a dispersant, solvent: PGM, solid content concentration: 35% by mass

[0199] Titanium oxide particle dispersion 3 - "LDB-014" manufactured by Ishihara Sangyo, containing titanium oxide particles surface-treated with a silane coupling agent having a methacryloyl group and a dispersant, solvent: PGM, solid content concentration: 20 mass%

[0200] Titanium oxide particle dispersion 4 - "RTTPGM20WT%-H30" manufactured by CIK NanoTek, containing titanium oxide particles and additives, solvent: propylene glycol monomethyl ether acetate (PGMEA), solid content concentration: 20% by mass

[0201] Titanium oxide particle dispersion 5 - "ELCOM TGX-21A" manufactured by Nippon Gas Catalyst & Chemicals Co., Ltd., containing titanium oxide particles, tin oxide particles, and zirconium oxide particles surface-treated with a silane coupling agent having a methacryloyl group, solvent: PGM, solid content concentration: 20% by mass

[0202] Titanium oxide particle dispersion 6 - "NS446" manufactured by TAYCA, containing titanium oxide particles, tin oxide particles, zirconium oxide particles, amine, solvent: PGMEA, solid content concentration: 36% by mass

[0203] Titanium oxide particle dispersion 7: a mixture of the following titanium oxide particle dispersion 8 and the above-mentioned titanium oxide particle dispersion 1 at a mass ratio of 1:74, solid content concentration: 45% by mass.

[0204] Titanium oxide particle dispersion 8 contains titanium oxide particles "SA-100" (manufactured by TAYCA) and two dispersants. As dispersants, 1 part by mass of "SN Dispersant 9228" (manufactured by San Nopco, polyol-type nonionic surfactant) and "SN Sperse 70" (manufactured by San Nopco, nonionic surfactant, aliphatic amide surfactant, diethanolamine) were added to 100 parts by mass of SA-100, and then adjusted to a solid content concentration of 37% by mass using a solvent (PGM), and dispersed using a homogenizer (1000 rpm, 10 minutes).

[0205] Photopolymerization initiator - the above-mentioned "Omnirad 127"

[0206] The titanium oxide particle dispersions 1 to 7 were evaluated for the presence or absence of surface modification by a reactive group-containing silane coupling agent (SCA), particle size, and content (unit: mass %) of each component. The evaluation methods and results are summarized below.

[0207] <Preparation of Composition for Forming Low Refractive Index Layer>

[0208] The components were mixed in such a manner that, in terms of mass %, the ultraviolet curable resin was 47.1 mass %, the alumina sol was 3.5 mass %, the fluorine-containing compound was 8.2 mass %, the hollow silica particles were 35.8 mass %, and the photopolymerization initiator was 5.3 mass %, and then the solid content concentration was adjusted to 3 mass % using a solvent (MEK / PGM=1 / 3), thereby preparing a composition for forming a low refractive index layer.

[0209] The materials used as the constituent components of the composition for forming a low refractive index layer are as follows.

[0210] ·Ultraviolet curable resin - the above-mentioned "Aronix MT-3041"

[0211] Alumina sol - "LIODURAS KT-110AL" manufactured by Toyochem, 25% by mass of alumina particles (average particle size: 110 nm), 15% by mass of photosensitive monomer and resin, solvent (MEK, cyclohexanone, aliphatic solvent)

[0212] Fluorochemicals: "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd., perfluoroalkyl-containing (meth)acrylate, solvent: MIBK, solid content concentration: 20% by mass

[0213] Hollow silica particles - "THRULYA4320" manufactured by JGC Catalysts & Chemicals, average particle size: 60 nm, solvent: MIBK, solid content concentration: 20% by mass

[0214] Photopolymerization initiator - the above-mentioned "Omnirad 127"

[0215] <Production of hard coating>

[0216] For each of Examples 1 to 3 and Comparative Examples 1 to 5, a hard coat layer-forming composition was applied onto a substrate film ("Lumirror #50-U403" manufactured by TORAY, a polyethylene terephthalate film, 50 μm thick) using a #4 wire rod. After drying at 80°C for 3 minutes, an electrodeless (microwave) lamp was used to irradiate the substrate film with a light intensity of 80 mJ / cm 2 Ultraviolet rays form a hard coating.

[0217] <Production of medium refractive index layer>

[0218] For each of Examples 1 to 3 and Comparative Examples 1 to 5, a medium refractive index layer forming composition was applied to the surface of the hard coating layer using a #4 wire rod, dried at 80°C for 60 seconds, and then irradiated with a light intensity of 150 mJ / cm using an electrodeless (microwave) lamp. 2 Ultraviolet rays form a medium refractive index layer.

[0219] <Production of high refractive index layer>

[0220] For each of Examples 1 to 3 and Comparative Examples 1 to 5, a high refractive index layer-forming composition was applied to the surface of the medium refractive index layer using a #4 wire rod, dried at 80° C. for 60 seconds, and then irradiated with a light intensity of 150 mJ / cm using an electrodeless (microwave) lamp. 2 Ultraviolet rays form a high refractive index layer.

[0221] <Production of low refractive index layer>

[0222] For each of Examples 1 to 3 and Comparative Examples 1 to 5, a low refractive index layer-forming composition was applied to the surface of the high refractive index layer using a #4 wire rod, dried at 80° C. for 60 seconds, and then irradiated with a light intensity of 150 mJ / cm using an electrodeless (microwave) lamp. 2 Ultraviolet rays form a low refractive index layer.

[0223] According to the above, an antireflection film was produced.

[0224] <Evaluation Method>

[0225] (Particle size of titanium oxide particles)

[0226] For titanium oxide particle dispersions 1 to 7, PGM was added to adjust the concentration so that the solid content concentration became 10% by mass, and the average particle size (D50) based on volume, the cumulative 90% particle size (D90) based on volume, and the cumulative 10% particle size (D10) based on volume were measured by dynamic light scattering using a nanoparticle size measurement system ("nanoSAQLA" manufactured by Otsuka Electronics). In addition, the polydispersity index (PDI) of titanium oxide particles was calculated according to the following formula (1).

[0227] PDI=(D90-D10) / D50 (1)

[0228] (Composition of Titanium Oxide Particle Dispersion)

[0229] 1 g of each of the titanium oxide particle dispersions 1 to 7 was collected on an aluminum petri dish and placed in a constant temperature bath at 100° C. for 1 hour to volatilize the volatile components. The weight ratio of the elements contained in the surface of the obtained titanium oxide particle film was measured by energy dispersive X-ray spectroscopy using a scanning electron microscope (“JCM-7000” manufactured by JEOL Ltd.).

[0230] (Thickness and refractive index of each layer)

[0231] The thickness and refractive index of the hard coating layer, the medium refractive index layer, the high refractive index layer, and the low refractive index layer were evaluated. At this time, each time each layer was formed, the reflection spectrum in the wavelength region of 380 to 780 nm obtained using a microscopic spectrophotometer ("OPTM-F1" manufactured by Otsuka Electronics) and the theoretical spectrum derived based on the Fresnel formula were curve-fitted by the least squares method to calculate the thickness of each layer and the refractive index at a wavelength of 550 nm.

[0232] (Abrasion resistance)

[0233] Using a flat wear tester ("DAS-400" manufactured by Daiei Kagaku Seiki Seisakusho), steel wool #0000 (manufactured by Nippon Steel Wool Co., Ltd.) fixed on a 20 mm × 20 mm flat friction piece was placed on the surface of the low refractive index layer of the anti-reflection film and moved back and forth. The stroke length of the test bench was set to 50 mm, the reciprocating speed of the test bench was set to 60 reciprocating times / minute, and the reciprocating movement was performed 1500 times with a load of 1.0 kg. The anti-reflection film after the test was visually observed and evaluated according to the following criteria.

[0234] A: No scratches at all, very high scratch resistance

[0235] B: There are scratches less than 10 mm in length, but no scratches longer than 10 mm. The scratch resistance is not a problem in practical use.

[0236] C: There are 1 to 9 scratches longer than 10 mm, and the scratch resistance is low

[0237] D: There are more than 10 scratches with a length of more than 10 mm, and the scratch resistance is very low

[0238] (Haze(Hz))

[0239] The haze (Hz) of the entire antireflection film was measured using "Haze Meter NDH7000" manufactured by Nippon Denshoku Industries in accordance with the method of JIS-K7136. When the haze is 2.0 or less, it can be evaluated that the transparency is high.

[0240] (Visual Reflectivity)

[0241] The back side of the anti-reflection film (the side opposite to the low refractive index layer) was roughened with #400 sandpaper and fully coated with black paint. The 5° regular reflectance of the surface of the anti-reflection film at a wavelength of 380nm to 780nm was measured using an ultraviolet visible near-infrared spectrophotometer ("UV-3600" manufactured by Shimadzu Corporation), and the visual sensitivity reflectance was calculated by multiplying the measured value by the relative visual sensitivity value. If the visual sensitivity reflectance is 0.5% or less, it can be considered that the anti-reflection property is sufficient.

[0242] <Evaluation Results>

[0243] Table 1 shows the results of evaluating the composition of titanium oxide particle dispersions 1 to 7 used for forming the high refractive index layer. In addition, Table 2 shows the evaluation results of Examples 1 to 3 and Comparative Examples 1 to 5 together with the component composition of the high refractive index layer and the thickness of each layer. In Table 2, "Titanium oxide content (relative to solid content)" is the amount calculated based on the content of Ti in the composition of the titanium oxide particle dispersions in Table 1, the solid content concentration of each dispersion, and the composition of the high refractive index layer in Table 2.

[0244] [Table 1]

[0245]

[0246] [Table 2]

[0247]

[0248] In the curable composition constituting the high refractive index layer, in Comparative Examples 1 and 2 in which the titanium oxide particles were not surface-treated with a silane coupling agent having a reactive group, the scratch resistance was poor.

[0249] In Comparative Examples 3 and 4, the D50 of the titanium oxide particles in the high refractive index layer is less than 20 nm. In these samples, the visual reflectance exceeds 0.5%. Since the D50 of the titanium oxide particles in the high refractive index layer is too small, it is impossible to disperse titanium oxide at a high content in the titanium oxide particle dispersion (refer to the Ti content of the composition in Table 1), and it is impossible to make the titanium oxide particles contained in the high refractive index layer have a sufficient concentration (refer to the titanium oxide content in Table 2), which can be interpreted as the refractive index of the high refractive index layer is insufficient. Moreover, in Comparative Example 4, since the titanium oxide particles in the curable composition constituting the high refractive index layer are not surface-treated by a silane coupling agent having a reactive group, the scratch resistance is also poor.

[0250] In Comparative Example 5, the D90 of the titanium oxide particles in the high refractive index layer exceeded 120 nm, and accordingly, the haze value indicating the level of transparency became larger.

[0251] Unlike these comparative examples, in Examples 1 to 3, the titanium oxide particles contained in the curable composition constituting the high refractive index layer were surface-treated with a silane coupling agent having a reactive group, and had a D50 of 20 nm or more and a D90 of 120 nm or less. Correspondingly, in Examples 1 to 3, high scratch resistance evaluated as A was obtained. In addition, high anti-reflection properties expressed by a visual sensitivity reflectance of 0.5% or less and high transparency expressed by a haze of 2.0 or less were obtained.

[0252] As shown above, since it has a substrate film, a hard coating layer formed on the surface of the substrate film, a high refractive index layer formed on the surface of the hard coating layer, and a low refractive index layer formed on the surface of the high refractive index layer, the high refractive index layer is composed of a cured product of an ionizing radiation curable composition, the ionizing radiation curable composition contains a (meth)acrylate compound having a reactive group and titanium oxide particles surface-treated by a silane coupling agent having a reactive group capable of forming a bond with the (meth)acrylate compound, the titanium oxide particles have an average particle size (D50) based on volume of 20 nm or more, and a cumulative 90% particle size (D90) based on volume of 120 nm or less, therefore, due to the contribution of the high refractive index layer, it becomes an anti-reflection film with high anti-reflection properties and excellent scratch resistance.

[0253] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments at all, and various modifications can be made without departing from the gist of the present invention.

[0254] Description of Reference Numerals

[0255] 10, 20, 30, 40 anti-reflection film

[0256] 12 Base film

[0257] 14Hard coating

[0258] 15 medium refractive index layer

[0259] 16 High refractive index layer

[0260] 18 Low refractive index layer

[0261] 22 transparent adhesive layer

[0262] 24 Release film

[0263] 26 Adhesive layer

[0264] 28 protective film.

Claims

1. An anti-reflection film, characterized in that: A substrate film, a hard coating layer formed on a surface of the substrate film, a high refractive index layer formed on a surface of the hard coating layer, and a low refractive index layer formed on a surface of the high refractive index layer. The high refractive index layer is composed of a cured product of an ionizing radiation curable composition, wherein the ionizing radiation curable composition contains a (meth)acrylate compound having a reactive group and titanium oxide particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the (meth)acrylate compound. The titanium oxide particles have an average particle size D50 of 20 nm or more in a cumulative particle size distribution based on volume, and a 90% particle size D90 of 120 nm or less in a cumulative particle size distribution based on volume.

2. The antireflection film according to claim 1, wherein The refractive index of the high refractive index layer at a wavelength of 550 nm is 1.83 or more and 2.00 or less. The refractive index of the low refractive index layer at a wavelength of 550 nm is greater than or equal to 1.35 and less than or equal to 1.

49.

3. The antireflection film according to claim 1 or claim 2, wherein: A medium refractive index layer having a refractive index at a wavelength of 550 nm higher than that of the hard coating layer and lower than that of the high refractive index layer is provided between the hard coating layer and the high refractive index layer.

4. A method for manufacturing an anti-reflection film, A hard coating layer is formed on the surface of the base film. An ionizing radiation curable composition is applied on the surface of the hard coating layer to form a high refractive index layer, wherein the ionizing radiation curable composition contains a (meth)acrylate compound having a reactive group and a particle dispersion in which titanium oxide particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the (meth)acrylate compound are dispersed in a solvent, forming a low refractive index layer on the surface of the high refractive index layer, The method for producing the anti-reflection film is characterized in that: In the particle dispersion, the content of titanium atoms is 40% by mass or more and 80% by mass or less relative to 100% by mass of the total solid content.

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