Anti-reflective film

Abstract

To provide an antireflection film which has an excellent antireflection property and scratch resistance, and also has a high antifouling property and wear durability.SOLUTION: An antireflection film 10 has a base material film 12, a hard coat layer 14 formed on a surface of the base material film 12, a low refractive index layer 16 formed on a surface of the hard coat layer 14, a primer layer 17 formed on a surface of the low refractive index layer 16, and an antifouling layer 18 formed on a surface of the primer layer 17, wherein the antifouling layer 18 is composed of a cured product of a composition containing fluorine-containing (meth)acrylate, a content of the fluorine-containing (meth)acrylate in the antifouling layer 18 is 90 mass% or more based on a total amount of a solid content of the antifouling layer 18, a thickness dLR of the low refractive index layer 16 is 46 nm or more, a thickness dPR of the primer layer 17 is 8 nm or more, and a total thickness dLR+dPR of the low refractive index layer 16 and the primer layer 17 is 60 nm or more and 100 or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an antireflection film, and more particularly to an antireflection film suitably used on the surface of displays such as touch panels of liquid crystal displays, organic EL displays, smartphones, etc.

Background Art

[0002] An antireflection film may be disposed on the surface of a display such as a touch panel of a liquid crystal display, an organic EL display, a smartphone, etc. to prevent external light from reflecting onto the screen. As an antireflection film, one having a hard coat layer and an antireflection layer (low refractive index layer) on a base film in this order is known. For example, in Patent Document 1 based on the applicant's application, by studying the composition of the low refractive index layer formed on the surface of the hard coat layer, the antireflection property, scratch resistance, and antifouling property of the antireflection film are improved. In Patent Document 1, a fluorine-containing compound is contained in the low refractive index layer, which contributes to the improvement of the antifouling property.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an antireflection film, particularly one disposed on the surface of a touch panel and frequently subjected to finger contact, high antifouling properties are required. As disclosed in Patent Document 1, the antifouling properties of an antireflection film can be improved by adding a substance having an antifouling effect, such as a fluorine-containing compound, to the low refractive index layer constituting the antireflection film. On the other hand, a form in which an antifouling layer containing such a substance having an antifouling effect is provided as a layer independent of the low refractive index layer on the surface of the low refractive index layer is also used. However, even when an antifouling layer is provided, there are cases where sufficiently high antifouling properties cannot be obtained, or where the surface wears when repeated finger contact occurs, resulting in a decrease in antifouling properties. In an antireflection film that is frequently subjected to finger contact, in addition to having high antireflection properties and antifouling properties, high scratch resistance and high wear durability are important characteristics from the perspective of durability during use.

[0005] The problem to be solved by the present invention is to provide an antireflection film having excellent antireflection properties and scratch resistance, as well as high antifouling properties and wear durability.

Means for Solving the Problem

[0006] To solve the above problems, the antireflection film according to the present invention has the following configuration. [1] The antireflection film according to the present invention includes a base film, a hard coat layer formed on the surface of the base film, a low refractive index layer formed on the surface of the hard coat layer, a primer layer formed on the surface of the low refractive index layer, and an antifouling layer formed on the surface of the primer layer. The antifouling layer is composed of a cured product of a composition containing a fluorine-containing (meth)acrylate. The content of the fluorine-containing (meth)acrylate in the antifouling layer is 90% by mass or more based on the total solid content of the antifouling layer. The thickness d of the low refractive index layer LR is 46 nm or more, and the thickness d of the primer layer PR is 8 nm or more. The total thickness d of the low refractive index layer and the primer layer LR +d PRThe wavelength is between 60nm and 100nm.

[0007] [2] In the embodiment of [1] above, the low refractive index layer is preferably composed of a cured product of a composition comprising a binder resin containing a (meth)acrylate compound, inorganic oxide particles, and hollow silica particles, and the primer layer is preferably composed of a cured product of a composition containing a binder resin containing a (meth)acrylate compound and not containing particles made of inorganic oxides.

[0008] [3] In the embodiment described in [2] above, the binder resin contained in the primer layer may be the same as the binder resin contained in the low refractive index layer.

[0009] [4] In the embodiments of [2] or [3] above, the low refractive index layer may not contain a fluorine-containing compound. [Effects of the Invention]

[0010] The anti-reflective film according to the present invention having the configuration described in [1] above comprises a base film, a hard coat layer formed on the surface of the base film, a low refractive index layer formed on the surface of the hard coat layer, a primer layer formed on the surface of the low refractive index layer, and an anti-fouling layer formed on the surface of the primer layer, wherein the anti-fouling layer is composed of a cured product of a composition containing fluorine-containing (meth)acrylate, the content of the fluorine-containing (meth)acrylate in the anti-fouling layer is 90% by mass or more based on the total solid content of the anti-fouling layer, and the thickness d of the low refractive index layer LR The thickness of the primer layer is 46 nm or greater. PR The total thickness of the low refractive index layer and the primer layer is d, which is 8 nm or greater. LR +d PRThe wavelength is between 60 nm and 100 nm. By having an antifouling layer having the above composition, the anti-reflective film becomes excellent in terms of antifouling, scratch resistance, and abrasion resistance. Furthermore, a primer layer is formed between the antifouling layer and the low refractive index layer, and the thickness of the primer layer and the low refractive index layer is as described above, thereby further enhancing the antifouling and abrasion resistance of the anti-reflective film while maintaining its anti-reflective properties and scratch resistance.

[0011] In the embodiment described in [2] above, the low refractive index layer is composed of a cured product of a composition comprising a binder resin containing a (meth)acrylate compound, inorganic oxide particles, and hollow silica particles, and the primer layer is composed of a cured product of a composition containing a binder resin containing a (meth)acrylate compound and not containing particles made of inorganic oxides. As a result of the contributions of the low refractive index layer and the primer layer, the anti-reflective film has excellent optical properties such as stain resistance, scratch resistance, abrasion resistance, and anti-reflective properties.

[0012] In the embodiment described in [3] above, the binder resin contained in the primer layer is the same as the binder resin contained in the low refractive index layer, thereby increasing the adhesion between the low refractive index layer and the primer layer, and thereby significantly improving the abrasion resistance of the anti-reflective film.

[0013] In the embodiment described in [4] above, the low refractive index layer does not contain a fluorine-containing compound. In the anti-reflective film of the present invention, the anti-fouling layer exhibits high anti-fouling properties, so there is no need to include a fluorine-containing compound in the low refractive index layer for the purpose of improving anti-fouling properties. By making the low refractive index layer free of a fluorine-containing compound, the scratch resistance of the anti-reflective film is less likely to be impaired. [Brief explanation of the drawing]

[0014] [Figure 1] This is a cross-sectional view of an anti-reflective film according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view of an anti-reflective film according to a second embodiment of the present invention. [Figure 3] This is a cross-sectional view of an anti-reflective film according to a third embodiment of the present invention. [Figure 4] This is a cross-sectional view of an anti-reflective film according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0015] The present invention will be described in detail below. In this specification, unless otherwise specified, all physical properties refer to values ​​at room temperature and in air. In this specification, unless otherwise specified, the refractive index of a substance and a material layer refers to the refractive index at a measurement wavelength of 589.3 nm.

[0016] <Anti-reflective film of the first embodiment> Figure 1 is a cross-sectional view of an anti-reflective film according to the first embodiment of the present invention. As shown in Figure 1, the anti-reflective film 10 according to the first embodiment of the present invention comprises a base film 12, a hard coat layer 14 formed on the surface of the base film 12, a low refractive index layer 16 formed on the surface of the hard coat layer 14, a primer layer 17 formed on the surface of the low refractive index layer 16, and an anti-fouling layer 18 formed on the surface of the primer layer 17. In this embodiment, each of the above layers is laminated in order without any other layers in between. The anti-fouling layer 18 is the outermost layer exposed on the entire anti-reflective film 10.

[0017] (Base film) The base film 12 is not particularly limited as long as it is transparent. Examples of base film 12 include transparent polymer films and glass films. Transparency means that the total light transmittance in the visible light wavelength range is 50% or more, and more preferably 85% or more. The above total light transmittance can be measured in accordance with JIS K7361-1 (1997). The thickness of the base film 12 is not particularly limited, but from the viewpoint of ease of handling, it is preferably in the range of 2 μm to 500 μm. More preferably it is in the range of 2 μm to 200 μm. In general, "film" refers to a material with a thickness of less than 0.25 mm, but even if the thickness is 0.25 mm or more, if it can be wound into a roll, it is also included as a "film".

[0018] Examples of polymer materials for the base film 12 include 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, polyolefin resins such as polypropylene resin, polyethylene resin, polycycloolefin resin, and cycloolefin copolymer resin, cellulose-based resins such as triacetylcellulose resin and diacetylcellulose resin, polyphenylene sulfide resin, polyvinyl chloride resin, polyvinylidene chloride resin, and polyvinyl alcohol resin. The polymer material for the base film 12 may consist of only one of these, or a combination of two or more. Of these, polyethylene terephthalate resin, polyimide resin, polycarbonate resin, poly(meth)acrylate resin, polycycloolefin resin, cycloolefin copolymer resin, and triacetylcellulose resin are more preferred from the viewpoint of optical properties and durability.

[0019] The base film 12 may consist of a single layer comprising a layer containing one or more of the above-mentioned polymer materials, or it may consist of two or more layers, such as a layer containing one or more of the above-mentioned polymer materials and a layer containing one or more of a different polymer material.

[0020] (Hard coat layer) The hard coat layer 14 contributes to improving the scratch resistance of the anti-reflective film 10. The hard coat 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 electromagnetic waves or charged particle beams that have energy quanta capable of polymerizing or crosslinking molecules. Examples of ionizing radiation include electromagnetic waves such as ultraviolet rays (UV), X-rays, and gamma rays, and charged particle beams such as electron beams (EB), alpha rays, and ion beams. Of these, ultraviolet rays (UV) are particularly preferred from the viewpoint of productivity. Hereinafter, the ionizing radiation-curable composition may simply be referred to as the curable composition. In this specification, "(meth)acrylate" means "at least one of acrylate and methacrylate." "(meth)acryloyl" means "at least one of acryloyl and methacryloyl." "(meth)acrylic" means "at least one of acrylic and methacrylic." A "(meth)acrylate compound" is a compound having a (meth)acryloyl group, and examples include monomers, oligomers, and prepolymers. Hereinafter, (meth)acrylate compounds may be simply referred to as (meth)acrylate.

[0021] The (meth)acrylate may be monofunctional (meth)acrylate or polyfunctional (meth)acrylate. Alternatively, it may be a combination of monofunctional (meth)acrylate and polyfunctional (meth)acrylate. From the viewpoint of improving curability, the curable composition more preferably contains polyfunctional (meth)acrylate as the (meth)acrylate.

[0022] Examples of (meth)acrylates include urethane (meth)acrylate, silicone (meth)acrylate, alkyl (meth)acrylate, and aryl (meth)acrylate. Of these, urethane (meth)acrylate, particularly urethane (meth)acrylate oligomers, are preferred. Specific examples of urethane (meth)acrylate include those obtained by reacting a polyisocyanate compound with a hydroxyl group-containing (meth)acrylate compound and, if necessary, a polyol compound. Examples of polyisocyanate compounds include diisocyanate compounds such as hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and 4,4'-diphenylmethane diisocyanate, as well as their nurate-modified, adduct-modified, and biuret-modified forms. Examples of hydroxyl group-containing (meth)acrylate compounds include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane diacrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and their polyoxyalkylene and polylactone modified forms. Examples of polyol compounds include ethylene glycol, propylene glycol, butanediol, hexanediol, polyoxyethylene glycol, polyoxypropylene glycol, glycerin, trimethylolpropane, pentaerythritol, biphenol, and bisphenol. When the curable composition for forming the hard coat layer 14 contains urethane (meth)acrylate as an ultraviolet-curable resin, the hard coat layer 14 has appropriate flexibility, which increases the bending resistance of the anti-reflective film 10, making it suitable for use in flexible displays that are repeatedly bent, such as foldable displays and rollable displays. Furthermore, even if the base film 12 is formed from, for example, polycycloolefin or cycloolefin copolymer, and is relatively brittle, cracking of the base film 12 can be easily suppressed.

[0023] It is preferable that the curable composition further contains a pentaerythritol (meth)acrylate compound as the (meth)acrylate. Specific examples of pentaerythritol (meth)acrylate compounds include 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, and the like. In particular, it is preferable that the curable composition contains pentaerythritol tri(meth)acrylate.

[0024] The curable composition forming the hard coat layer 14 may or may not contain a non-UV curable resin in addition to a UV-curable resin. Furthermore, the curable composition forming the hard coat layer 14 may contain a photopolymerization initiator. Additionally, generally available additives may be included as needed. Examples of additives include dispersants, leveling agents, defoamers, vibration modifiers, antifouling agents, antibacterial agents, flame retardants, slip agents, antistatic agents, inorganic particles, and resin particles. Additionally, solvents may be included as needed.

[0025] Examples of non-UV curable resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include polyester resins, polyether resins, polyolefin resins, and polyamide resins. Examples of thermosetting resins include unsaturated polyester resins, epoxy resins, alkyd resins, and phenolic resins.

[0026] Examples of photopolymerization initiators include alkylphenone-based, acylphosphine oxide-based, and oxime ester-based photopolymerization initiators. Examples of alkylphenone-based photopolymerization initiators include 2,2'-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl-ketone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methylpropane-1- Examples include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-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, and N,N-dimethylaminoacetophenone. Examples of acylphosphine oxide-based photopolymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. Examples of oxime ester-based photopolymerization initiators include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime), and ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime). These photopolymerization initiators may be used individually or in combination of two or more.

[0027] The content of the photopolymerization initiator is preferably in the range of 0.1% by mass or more and 10% by mass, based on the total solid content of the curable composition. More preferably, it is 1% by mass or more, and 5% by mass or less.

[0028] Inorganic particles and resin particles are added to the hard coat layer 14 for purposes such as preventing blocking of the hard coat layer 14 or adjusting the refractive index of the hard coat layer 14. By forming fine surface irregularities on the hard coat layer 14 with the added inorganic particles and resin particles, it is easier to suppress blocking, where the front and back surfaces adhere to each other, when the hard coat film, consisting of the base film 12 and the hard coat layer 14, is wound into a roll before the low refractive index layer 16 is formed.

[0029] Examples of inorganic particles that can adjust the refractive index of the hard coat layer 14 include metal oxide particles made from metal oxides such as titanium, zirconium, tin, zinc, silicon, niobium, aluminum, chromium, magnesium, germanium, gallium, antimony, and platinum. These may be used individually as optically adjustable inorganic particles, or in combination of two or more types. Among these, titanium oxide particles and zirconium oxide particles are particularly preferred from the viewpoint of achieving both high refractive index and transparency. Examples of resin particles include resin particles made from 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. These may be used individually as resin particles, or in combination of two or more types.

[0030] The thickness of the hard coat layer 14 is not particularly limited, but is preferably 0.5 μm or more from the viewpoint of having sufficient hardness. More preferably 0.75 μm or more. Furthermore, it is preferably 20 μm or less from the viewpoint of easily suppressing curl caused by the difference in thermal shrinkage with the base film 12. More preferably 10 μm or less. The thickness of the hard coat layer 14 is the thickness of the relatively smooth portion in the thickness direction where there are no irregularities caused by inorganic particles or resin particles.

[0031] From the viewpoint of suppressing interference unevenness arising from the difference in refractive indices between the transparent substrate film 12 and the hard coat layer 14, the refractive index of the hard coat layer 14 is preferably in the range of 1.49 to 1.56. The arithmetic mean roughness Ra of the surface on which the surface irregularities of the hard coat layer 14 are formed is preferably in the range of 0.3 nm to 20 nm from the viewpoint of suppressing blocking, etc. More preferably it is 0.5 nm or more, and also 10 nm or less.

[0032] Solvents used in the curable composition for forming the hard coat layer 14 include alcohol-based 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), and diethylene glycol monobutyl ether; ketone-based solvents such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, and acetone; aromatic solvents such as toluene and xylene; ester-based solvents such as ethyl acetate (EtAc), propyl acetate, isopropyl acetate, and butyl acetate (BuAc); and amide-based solvents such as N-methylpyrrolidone, acetamide, and dimethylformamide. These solvents may be used individually or in combination of two or more.

[0033] The solid content concentration (concentration of components other than the solvent) of the curable composition should be determined appropriately, taking into consideration the coating properties, film thickness, etc. For example, it may be set to 1% to 90% by mass, 1.5% to 80% by mass, or 2% to 70% by mass.

[0034] (Low refractive index layer) In the anti-reflective film 10 according to this embodiment, a low refractive index layer 16 is provided on the surface of the hard coat layer 14 as an anti-reflective layer. The low refractive index layer 16 has a lower refractive index than the hard coat layer 14, and the difference in refractive index between the two layers produces an anti-reflective effect.

[0035] The low refractive index layer 16 is not particularly limited in composition, but it is preferably composed of a cured product of a composition containing a binder resin, inorganic oxide particles, and hollow silica particles. In particular, it is preferably composed of a cured product of an ionizing radiation-curable composition containing these components. Preferred compositions are described below.

[0036] As the binder resin, thermosetting compounds and ionizing radiation-curable compounds, including ultraviolet-curable compounds, are preferred from the viewpoint of improving the scratch resistance of the low refractive index layer 16. From the viewpoint of productivity of the anti-reflective film 10, the binder resin is preferably in the form of an ultraviolet-curable compound.

[0037] Examples of UV-curable resins include monomers, oligomers, and prepolymers having UV-reactive reactive groups. Examples of UV-reactive reactive groups include radical polymerization-type reactive groups having ethylenically unsaturated bonds, such as acryloyl groups, methacryloyl groups, allyl groups, and vinyl groups, and cationic polymerization-type reactive groups such as oxetanyl groups. Of these, acryloyl groups, methacryloyl groups, and oxetanyl groups are more preferred, and acryloyl groups and methacryloyl groups are particularly preferred. In other words, it is particularly preferable to use (meth)acrylate compounds.

[0038] Examples of (meth)acrylate compounds include urethane (meth)acrylate, silicone (meth)acrylate, alkyl (meth)acrylate, and aryl (meth)acrylate. The (meth)acrylate may consist only of monofunctional (meth)acrylate, or it may consist of polyfunctional (meth)acrylate, or it may consist of a combination of monofunctional (meth)acrylate and polyfunctional (meth)acrylate. It is more preferable that the (meth)acrylate includes polyfunctional (meth)acrylate.

[0039] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, and 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, tricyclodecanyl (meth)acrylate, di Cyclopentanyl (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)-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,Examples include ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate.

[0040] Examples of polyfunctional (meth)acrylates include difunctional (meth)acrylates, trifunctional (meth)acrylates, and tetrafunctional (meth)acrylates. More specifically, these include 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, and trimethylolpropane tri(meth)acrylate. Examples include 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, and tripentaerythritol octa(meth)acrylate.

[0041] The UV-curable resin may consist of one type of (meth)acrylate as described above, or it may consist of two or more types. From the viewpoint of improving scratch resistance, the UV-curable resin preferably contains a polyfunctional (meth)acrylate with five or more functions, and it is also preferable to increase the content of the polyfunctional (meth)acrylate with five or more functions.

[0042] Furthermore, it is preferable that the polyfunctional (meth)acrylate contains a dimer. Dimers of polyfunctional (meth)acrylates have excellent curing speed and can easily increase the curing rate of the curable composition, thereby further improving scratch resistance. In particular, it is preferable to include at least one selected from the group consisting of dimers of pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, and it is more preferable to include at least one selected from the group consisting of dimers of pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

[0043] The content of the above-mentioned 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 polyfunctional (meth)acrylate, from the viewpoint of scratch resistance, transparency, and solubility in solvents. More preferably, it is 30% by mass or more and 40% by mass or less.

[0044] The inorganic oxide particles, when included in the low refractive index layer 16, form protrusions on the surface of the low refractive index layer 16. The formation of these protrusions on the surface of the low refractive index layer 16 by the inorganic oxide particles allows the low refractive index layer 16 to have good scratch resistance.

[0045] 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 cavities inside the particles, and particles with a cavity ratio of less than 5% of the volume of the solid particles. Hollow particles refer to particles that have cavities inside the particles, and particles with a cavity ratio of 5% or more of the volume of the hollow particles. When the inorganic oxide particles are solid particles, the scratch resistance of the low refractive index layer 16 is improved, and the scratch resistance of the antireflection film 10 is improved. When the inorganic oxide particles are hollow particles, the refractive index of the low refractive index layer 16 can be lowered to reduce light reflection. In the case of hollow particles, the cavity ratio is preferably 10% or more and 80% or less of the volume of the hollow particles. When the cavity ratio is 10% or more, the refractive index can be lowered to reduce light reflection. More preferably, it is 20% or more, and even more preferably 30% or more. On the other hand, when the cavity ratio is 80% or less, the decrease in the dispersibility of the inorganic oxide particles can be suppressed. More preferably, it is 60% or less.

[0046] Examples of the inorganic oxide particles include metal oxide particles composed of oxides of metals such as zirconium, silicon, aluminum, and calcium. These may be used alone as one kind of inorganic oxide particles or in combination of two or more kinds. Among these, from the viewpoints of low refractive index, excellent transparency, high hardness, etc., silica particles and alumina particles are preferable, and alumina particles are particularly preferable. The inorganic oxide particles may be surface-treated with a surface treatment agent such as a silane coupling agent.

[0047] The shape of the inorganic oxide particles is not particularly limited, and may be spherical, needle-like, flaky, rod-like, fibrous, amorphous, etc. Among these, a spherical shape is preferable.

[0048] The inorganic oxide particles form convex portions on the surface of the low refractive index layer 16. In order to obtain good scratch resistance, the average particle diameter r of the inorganic oxide particles and the thickness d of the low refractive index layer 16 LR The difference (r - d LR ) is preferably 10 nm or more. The difference (r - d LR) is more preferably 15 nm or more, and even more preferably 18 nm or more. On the other hand, from the viewpoint of suppressing the height of the formed protrusions and maintaining transparency, the difference (rd LR The thickness of the low refractive index layer 16 is 300 nm or less. More preferably it is 200 nm or less, and even more preferably 100 nm or less. LR This is used alone, and also with a thickness d of the primer layer 17. PR The sum of these will be determined to fall within a predetermined range, as will be explained later.

[0049] The average particle diameter r of the inorganic oxide particles is equal to the thickness d of the low refractive index layer 16. LR Depending on the circumstances, it is preferable that the particle size is in the range of 60 nm to 400 nm. More preferably, it is 70 nm or more, and even more preferably, 90 nm or more. Furthermore, it is more preferably 300 nm or less, and even more preferably 200 nm or less. The average particle diameter r of the inorganic oxide particles is a volume-based average arithmetic value obtained by the laser diffraction / scattering method in accordance with JIS Z8825, and includes not only the primary particle diameter but also the secondary particle diameter, which is the aggregate of particles.

[0050] The inorganic oxide particle content in the low refractive index layer 16 is preferably 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 16. When the inorganic oxide particle content in the low refractive index layer 16 is 0.1% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 16, excellent scratch resistance can be obtained. From this viewpoint, the inorganic oxide particle content in the low refractive index layer 16 is more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, relative to 100% by mass of the solid content of the low refractive index layer 16. Furthermore, when the inorganic oxide particle content in the low refractive index layer 16 is 4.0% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 16, high transparency can be obtained. From this viewpoint, the inorganic oxide particle content in the low refractive index layer 16 is more preferably 3.5% by mass or less, and even more preferably 3.2% by mass or less, relative to 100% by mass of the solid content of the low refractive index layer 16. The solid components of the low refractive index layer 16 referred to here are those components that are not immobilized in the binder resin and are liquid at room temperature, excluding those components. The solid components of the low refractive index layer 16 include inorganic oxide particles, hollow silica particles, and binder resin. Additives such as oil components and surfactants that are not immobilized in the binder resin are not included.

[0051] Hollow silica particles are particles with an average particle diameter smaller than the average thickness of the low refractive index layer 16. It is preferable that the hollow silica particles have an average particle diameter smaller than the inorganic oxide particles that form protrusions on the surface of the low refractive index layer 16. Hollow silica particles are particles that do not substantially contribute to the formation of surface irregularities in the low refractive index layer 16. Hollow silica particles are particles that have cavities inside, and the proportion of cavities is 5% or more of the volume. "Hollow" refers to a shell structure consisting of an outer shell and internal cavities, or a porous structure with numerous cavities. The hollow structure of hollow silica particles allows for a reduction in the refractive index of the low refractive index layer 16, thereby reducing light reflection. The shape of the hollow silica particles is not particularly limited, but spherical, spindle-shaped, oval, plate-shaped, cubic, and irregular shapes are preferred. Among these, spherical, plate-shaped, and cubic shapes are particularly preferred.

[0052] In hollow silica particles, the proportion of cavities is preferably 10% to 80% of the volume. When the proportion of cavities is 10% or more of the volume, the refractive index can be lowered, reducing light reflection. More preferably, it is 20% or more of the volume, and even more preferably 30% or more of the volume. On the other hand, when the proportion of cavities is 80% or less of the volume, the decrease in the dispersibility of the hollow silica particles can be suppressed. More preferably, it is 60% or less of the volume.

[0053] The average particle diameter of the hollow silica particles is preferably between 5 nm and 100 nm, although this depends on the thickness of the low refractive index layer 16. More preferably, it is 20 nm or more, and even more preferably, 40 nm or more. Furthermore, it is more preferably 80 nm or less, and even more preferably, 70 nm or less. When the average particle diameter of the hollow silica particles is within these preferred ranges, excellent anti-reflective effect and transparency of the low refractive index layer 16 can be obtained. The average particle diameter is a volume-based average arithmetic value obtained by the laser diffraction / scattering method in accordance with JIS Z8825. This includes not only the primary particle diameter but also the secondary particle diameter, which is the aggregate of particles.

[0054] The refractive index of the hollow silica particles is preferably in the range of 1.01 to 1.45. More preferably, it is in the range of 1.15 to 1.38, and even more preferably, in the range of 1.15 to 1.35. When the refractive index of the hollow silica particles is within this range, an excellent anti-reflective effect can be obtained.

[0055] The content of hollow silica particles in the low refractive index layer 16 is preferably 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 16. When the content of hollow silica particles in the low refractive index layer 16 is 6.0% by mass relative to 100% by mass of the solid content of the low refractive index layer 16, excellent anti-reflective properties can be obtained. Furthermore, from this viewpoint, the content of hollow silica particles in the low refractive index layer 16 is more preferably 10% by mass or more, even more preferably 12% by mass or more, and particularly preferably 15% by mass or more, relative to 100% by mass of the solid content of the low refractive index layer 16. When the content of hollow silica particles in the low refractive index layer 16 is 49.9% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 16, the decrease in scratch resistance can be suppressed. Furthermore, from this viewpoint, the content of hollow silica particles in the low refractive index layer 16 is more preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 25% by mass or less, based on 100% by mass of the solid content of the low refractive index layer 16.

[0056] Furthermore, the total amount of inorganic oxide particles and hollow silica particles in the low refractive index layer 16 is preferably 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 16. If the total amount of inorganic oxide particles and hollow silica particles in the low refractive index layer 16 is 10% by mass or more relative to 100% by mass of the solid content of the low refractive index layer 16, excellent scratch resistance can be obtained. Also from this viewpoint, the total amount of inorganic oxide particles and hollow silica particles in the low refractive index layer 16 is more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the solid content of the low refractive index layer 16. On the other hand, if the total amount of inorganic oxide particles and hollow silica particles in the low refractive index layer 16 is 50% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 16, the low refractive index layer 16 can sufficiently retain inorganic oxide particles and hollow silica particles, thus providing excellent scratch resistance. Furthermore, from this viewpoint, the total amount of inorganic oxide particles and hollow silica particles in the low refractive index layer 16 is more preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less, based on 100% by mass of the solid content of the low refractive index layer 16.

[0057] Thickness d of the low refractive index layer 16LR The thickness d of the low refractive index layer 16 is 46 nm or greater. When it is 46 nm or greater, the smoothness of the surface of the low refractive index layer 16 is increased, and the wear resistance of the anti-reflective film 10 can be improved. Also from this viewpoint, the thickness d of the low refractive index layer 16 LR The thickness d of the low refractive index layer 16 is more preferably 47 nm or more, and even more preferably 48 nm or more. LR There is no particular upper limit, but from the viewpoint of obtaining a high anti-reflective effect, it is preferably 90 nm or less, more preferably 85 nm or less, and even more preferably 75 nm or less. Note that the thickness d of the low refractive index layer 16 LR The thickness d of the low refractive index layer 16 can be determined as the average thickness of the low refractive index layer 16. If the low refractive index layer 16 contains inorganic oxide particles, the average thickness of the low refractive index layer 16 can be determined as the average thickness of the relatively smooth portion in the thickness direction where inorganic oxide particles 18 are not present. LR As will be explained later, the thickness d of the primer layer 17 PR The total thickness d LR +d PR It is also defined from this point of view.

[0058] The low refractive index layer 16 can be formed using a composition containing inorganic oxide particles, hollow silica particles, and a binder resin. As described above, the binder resin is preferably one that contains a (meth)acrylate compound or other reactive group that is UV-reactive (UV-curable resin). When the binder resin has a UV-reactive group, the scratch resistance of the low refractive index layer 16 is improved, and the scratch resistance of the anti-reflective film 10 is improved. When the binder resin has a UV-reactive group, the composition for forming the low refractive index layer 16 preferably further contains a photopolymerization initiator. The composition for forming the low refractive index layer 16 may also contain a solvent as needed. The binder resin of the low refractive index layer 16 may consist only of a UV-curable resin, or it may consist of a combination of a UV-curable resin and a non-UV-curable resin. As non-UV-curable resins, photopolymerization initiators, and solvents, the chemical species listed above as specific examples of those that can be contained in the composition for forming the hard coat layer 14 can also be suitably applied to the composition for forming the low refractive index layer 16.

[0059] 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 16. More preferably, it is 1% by mass or more and 5% by mass or less.

[0060] In addition, the low refractive index layer 16 may contain additives as needed. Examples of such additives include dispersants, leveling agents, defoaming agents, vibration modifiers, antibacterial agents, flame retardants, slip agents, and refractive index modifiers.

[0061] The low refractive index layer 16 may contain a fluorine-containing compound. Examples of fluorine-containing compounds include (meth)acrylates containing perfluoroalkyl groups, as well as compounds similar to the fluorine-containing (meth)acrylates contained in the antifouling layer 18 described below. When the low refractive index layer 16 contains a fluorine-containing compound, the antifouling properties of the anti-reflective film 10 are enhanced. However, in the anti-reflective film 10 according to this embodiment, an antifouling layer 18 is provided on the low refractive index layer 16, and the antifouling layer 18 exhibits high antifouling properties, so it is not necessary to include a fluorine-containing compound in the low refractive index layer 16 for the purpose of improving antifouling properties. Including a large amount of fluorine-containing compound in the low refractive index layer 16 weakens its adhesion to the primer layer 17, leading to a decrease in the scratch resistance of the anti-reflective film 10. However, by not including a fluorine-containing compound in the low refractive index layer 16, the scratch resistance of the anti-reflective film 10 can be enhanced. Even when a fluorine-containing compound is included in the low refractive index layer 16, it is preferable to keep its content to 1% by mass or less relative to 100% by mass of the solid content of the low refractive index layer 16.

[0062] The refractive index of the low refractive index layer 16 is not particularly limited as long as it is lower than that of the hard coat layer 14, but is preferably 1.35 or more and 1.52 or less. If the refractive index is 1.35 or more, the strength of the low refractive index layer 16 can be made sufficient, and good scratch resistance can be obtained. On the other hand, if the refractive index is 1.52 or less, the reflectivity of the anti-reflective film 10 can be made even lower. From the above viewpoint, the refractive index of the low refractive index layer 16 is more preferably 1.38 or more and 1.50 or less, and even more preferably 1.40 or more and 1.49 or less.

[0063] (Primer layer) In the anti-reflective film 10 according to this embodiment, a primer layer 17 is provided between the low refractive index layer 16 and the anti-fouling layer 18. The primer layer 17 plays a role in improving the adhesion between the low refractive index layer 16 and the anti-fouling layer 18, thereby improving the anti-fouling properties and abrasion resistance of the anti-reflective film 10.

[0064] The constituent material of the primer layer 17 is not particularly limited, but it is preferably composed of a cured product of a composition containing a binder resin. In particular, it is preferably composed of a cured product of an ionizing radiation-curable composition containing a binder resin.

[0065] Preferred binder resins include thermosetting compounds and ionizing radiation-curable compounds, including ultraviolet-curable compounds. From the viewpoint of productivity of the anti-reflective film 10, a form in which the binder resin consists of an ultraviolet-curable compound is preferred. In particular, it is preferable to use a binder resin containing a (meth)acrylate compound as the binder resin constituting the primer layer 17. Specific examples of (meth)acrylate compounds include those listed above as specific examples of (meth)acrylate species contained in the binder resin of the low refractive index layer 16, which can also be suitably applied to the primer layer 17.

[0066] The binder resin contained in the primer layer 17 may or may not contain the same components as the binder resin contained in the low refractive index layer 16. However, containing the same components improves the adhesion between the low refractive index layer 16 and the primer layer 17, resulting in a greater improvement in the antifouling properties and abrasion resistance of the anti-reflective film 10. Preferably, the binder resin contained in the primer layer 17 is composed of the same binder resin as the binder resin contained in the low refractive index layer 16. Alternatively, the composition of the binder resin contained in the primer layer 17 may be close to that of the binder resin contained in the low refractive index layer 16, for example, by having 90% or more by mass of the binder resin contained in the primer layer 17 being the same as the binder resin contained in the low refractive index layer 16. Furthermore, even if the composition of the binder resin contained in the primer layer 17 is the same as or close to the composition of the binder resin contained in the low refractive index layer 16, observation using an electron microscope or the like can often confirm the existence of a clear interface between the primer layer 17 and the low refractive index layer 16.

[0067] It is preferable that the primer layer 17 does not contain inorganic oxide particles, such as inorganic oxide particles or hollow silica particles contained in the low refractive index layer 16. In addition to inorganic oxide particles, it is preferable that it does not contain solid particles such as resin particles. By not containing solid particles, including inorganic oxide particles, the adhesion to the low refractive index layer 16 and the surface smoothness are improved, resulting in a high effect in improving the antifouling properties and abrasion resistance of the anti-reflective film 10. Even if the primer layer 17 contains solid particles, from the viewpoint of maintaining their effects, it is preferable to keep the particle size of these solid particles to 20 nm or less, and the solid particle content to 10% by mass or less relative to 100% by mass of the solid content of the primer layer 17. The solid content of the primer layer 17 referred to here is the component excluding components that are not fixed in the binder resin and are liquid at room temperature. The solid content of the primer layer 17 includes the binder resin, etc.

[0068] The primer layer 17 can be formed using a composition containing a binder resin. As described above, the binder resin is preferably one that contains a (meth)acrylate compound or other reactive group that is reactive to ultraviolet light (ultraviolet-curable resin), and in that case, the composition for forming the primer layer 17 preferably further contains a photopolymerization initiator. The composition for forming the primer layer 17 may contain a solvent as needed. The binder resin of the primer layer 17 may consist only of an ultraviolet-curable resin, or it may consist of a combination of an ultraviolet-curable resin and a non-ultraviolet-curable resin.

[0069] The non-UV curable resin, photopolymerization initiator, and solvent can be the same chemical species listed above as specific examples of those that may be included in the composition for forming the hard coat layer 14, and these can also be suitably applied to the composition for forming the primer layer 17. The content of the photopolymerization initiator is preferably in the range of 0.1% by mass or more and 20% by mass or less, based on the total solid content of the composition for forming the low refractive index layer 16. More preferably, it is 5% by mass or more and 15% by mass or less.

[0070] In addition, the primer layer 17 may contain additives as needed. Examples of such additives include dispersants, leveling agents, defoamers, vibration modifiers, antibacterial agents, flame retardants, slip agents, and refractive index modifiers.

[0071] Thickness d of primer layer 17 PR The thickness d of the primer layer 17 is 8 nm or greater. When it is 8 nm or greater, the surface smoothness of the low primer layer 17 is increased, and the wear resistance of the anti-reflective film 10 can be improved. Also from this viewpoint, the thickness d of the primer layer 17 PR The thickness of the primer layer 17 is more preferably 10 nm or more, and even more preferably 14 nm or more. PR There is no particular upper limit, but from the viewpoint of obtaining high scratch resistance and anti-reflective effect, it is preferably 55 nm or less, more preferably 50 nm or less, and even more preferably 45 nm or less. Note that the thickness d of the primer layer 17 PR This can be determined as the average thickness of the primer layer 17.

[0072] As described above, in the anti-reflective film 10 according to this embodiment, the thickness d of the low refractive index layer 16 LR The thickness of the primer layer 17 is 46 nm or greater. PR Furthermore, the total thickness of the low refractive index layer 16 and the primer layer 17, i.e., d LR +d PR However, it is between 60nm and 100nm. The total thickness d of the low refractive index layer 16 and the primer layer 17. LR +d PR By having a wavelength of 60 nm or more, the anti-reflective film 10 can achieve a high anti-reflective effect and excellent wear resistance. From the viewpoint of further enhancing these effects, d LR +d PR The thickness is preferably 60 nm or more, 62 nm or more, and more preferably 65 nm or more. On the other hand, the total thickness d of the low refractive index layer 16 and the primer layer 17 is also preferable. LR +d PRSince the wavelength is 100 nm or less, a high anti-reflective effect can be obtained in the anti-reflective film 10. From the viewpoint of enhancing this effect, d LR +d PR The refractive index is preferably 97 nm or less, and more preferably 95 nm or less. As shown below, it is preferable that the low refractive index layer 16 and the primer layer 17 have similar refractive indices, and optically they can be approximated as a single layer. Therefore, the total thickness d of the low refractive index layer 16 and the primer layer 17 is LR +d PR By defining the appropriate range, excellent anti-reflective properties can be obtained. Specifically, the total thickness d LR +d PR By setting the wavelength to 60 nm to 100 nm as described above, the overall difference between the wavelength at which the reflectance obtained by the optical interference effect is minimized (minimum reflection wavelength) and the relative luminous efficiency peak wavelength (shifts toward longer and shorter wavelengths) can be kept small, thereby obtaining a low luminous reflectance.

[0073] It is preferable that the primer layer 17 has a smoother surface than the low refractive index layer 16. This improves the adhesion between the low refractive index layer 16 and the antifouling layer 18, and enhances the effect of improving the adhesion between the low refractive index layer 16 and the antifouling layer 18 via the primer layer 17. This results in a high degree of improvement in the abrasion resistance of the anti-reflective film 10. In addition, having a smooth surface on the primer layer 17 also increases the smoothness of the surface of the antifouling layer 18 formed on it. This results in a high degree of improvement in the antifouling properties of the anti-reflective film 10. If the low refractive index layer 16 contains inorganic oxide particles, the smoothness of the surface of the primer layer 17 can be easily increased to be higher than the smoothness of the surface of the low refractive index layer 16 by making the primer layer 17 free of solid particles, including particles made of inorganic oxides.

[0074] Before forming the primer layer 17, the surface of the low refractive index layer 16 may be subjected to a surface treatment. Examples of surface treatments include corona treatment, plasma treatment, hot air treatment, ozone treatment, and ultraviolet treatment.

[0075] From the viewpoint of obtaining high anti-reflective properties in the anti-reflective film 10, it is preferable that the refractive index of the primer layer 17 differs from that of the low refractive index layer 16 by a small amount. Specifically, the refractive index of the primer layer 17 is preferably 1.56 or less, more preferably 1.52 or less, and even more preferably 1.50 or less. On the other hand, from the viewpoint of ensuring sufficient strength of the primer layer 17 and obtaining good scratch resistance, the refractive index of the primer layer 17 is preferably 1.40 or more, more preferably 1.43 or more, and even more preferably 1.45 or more.

[0076] (Anti-fouling layer) In the anti-reflective film 10 according to this embodiment, an anti-fouling layer 18 is provided on the surface of the primer layer 17. The anti-fouling layer 18 enhances the anti-fouling properties of the anti-reflective film 10.

[0077] The antifouling layer 18 is composed of a cured product of a composition containing fluorine-containing (meth)acrylate. In particular, it is preferable that it be composed of a cured product of an ionizing radiation-curable composition containing such fluorine-containing (meth)acrylate, and especially of an ultraviolet-curable composition.

[0078] The antifouling layer 18 is composed of a cured product of a composition containing fluorine-containing (meth)acrylate, so that the anti-reflective film 10 having the antifouling layer 18 on its surface has excellent antifouling properties and abrasion resistance. Specific examples of fluorine-containing (meth)acrylate include (meth)acrylate containing perfluoropolyether groups. A perfluoropolyether group refers to a polyether such as polyethylene glycol or polypropylene glycol in which all hydrogen atoms are replaced with fluorine. Examples include perfluoromethylene oxide (-CF2O-), perfluoroethylene oxide (-CF2CF2O-), perfluoropropylene oxide (-CF2CF2CF2O-), perfluoroisopropylene oxide (-CF(CF3)CF2O-), or a fluoropolyether group having a repeating structure formed by a combination of several of these. The number of repeating units in the above repeating structure is preferably 1 to 100. Specific examples of compounds include "KY-1203" and "KY-1207" from Shin-Etsu Chemical Co., Ltd., "Megafac RS-75" from DIC Corporation, "Optool DAC-HP" from Daikin Industries, Ltd., and "Futergent 601AD" and "Futergent 601ADH2" from Neos Corporation.

[0079] Furthermore, it is preferable that the fluorine-containing (meth)acrylate does not have urethane bonds in its structure. By the absence of urethane bonds in the structure of the fluorine-containing (meth)acrylate, the hardness of the antifouling layer 18 is increased, and the antifouling layer 18 is given particularly high abrasion resistance.

[0080] In the antifouling layer 18, the content of fluorine-containing (meth)acrylate is 90% by mass or more based on the total solid content of the antifouling layer 18. This allows for a high level of antifouling improvement effect due to fluorine-containing (meth)acrylate. In the anti-reflective film 10 according to this embodiment, since a primer layer 17 is provided below the antifouling layer 18, sufficient effects of improved adhesion to the lower layer and improved surface abrasion resistance are obtained. Therefore, it is not necessary to add a fluorine-free binder resin, such as a fluorine-free (meth)acrylate compound, to the antifouling layer 18 for the purpose of obtaining these effects. From the viewpoint of further enhancing the antifouling improvement effect, it is more preferable that the content of fluorine-containing (meth)acrylate in the antifouling layer 18 is 92% by mass or more based on the total solid content of the antifouling layer 18. Furthermore, it is more preferable that the entire amount of resin components constituting the antifouling layer 18, excluding unavoidable components, is fluorine-containing (meth)acrylate. The solid components of the antifouling layer 18 referred to here are those components that are not immobilized in the curable component of the antifouling layer 18 and are liquid at room temperature, excluding those components. The solid components of the antifouling layer 18 include fluorine-containing (meth)acrylate, etc.

[0081] The antifouling layer 18 can be formed using a composition containing fluorine-containing (meth)acrylate. The composition for forming the antifouling layer 18 can be arranged in a layer on the surface of the primer layer 17 and then cured. When the antifouling layer 18 is formed as a cured product of a composition having UV curability, the composition for forming the antifouling layer 18 preferably further contains a photopolymerization initiator.

[0082] As the photopolymerization initiator and solvent, the chemical species listed above as specific examples of those that can be contained in the composition for forming the hard coat layer 14 can also be suitably applied to the composition for forming the antifouling layer 18. The content of the photopolymerization initiator is preferably in the range of 0.1% by mass or more and 15% by mass or less, based on the total solid content of the composition for forming the antifouling layer 18. More preferably it is 3% by mass or more and 10% by mass or less.

[0083] In addition, the antifouling layer 18 may contain additives as needed. Examples of such additives include antifouling agents other than fluorine-containing (meth)acrylate, dispersants, leveling agents, defoamers, vibration modifiers, antibacterial agents, flame retardants, slip agents, and refractive index modifiers. However, from the viewpoint of improving the surface smoothness of the antifouling layer 18, it is preferable that the antifouling layer 18 does not contain solid particles, including metal acid particles. Even if the antifouling layer 18 contains solid particles, it is preferable to keep the particle size of the solid particles to 10 nm or less, and the solid particle content to 1% by mass or less relative to 100% by mass of the solid content of the antifouling layer 18.

[0084] The thickness of the antifouling layer 18 is preferably 1 nm or more. This allows for a high improvement in antifouling properties. More preferably, the thickness of the antifouling layer 18 is 3 nm or more, and even more preferably 5 nm or more. On the other hand, the thickness of the antifouling layer 18 is preferably 15 nm or less. This allows for a high level of anti-reflective properties of the anti-reflective film 10. More preferably, the thickness of the antifouling layer 18 is 10 nm or less.

[0085] The refractive index of the antifouling layer 18 is preferably 1.6 or less. If it is 1.6 or less, the anti-reflective properties of the anti-reflective film 10 can be kept high. More preferably, the refractive index of the antifouling layer 18 is 1.55 or less, and even more preferably 1.50 or less. On the other hand, the lower limit of the refractive index of the antifouling layer 18 is not particularly limited as long as the thickness of the antifouling layer 18 is within the above range, but it is preferably 1.3 or more, and more preferably 1.35 or more.

[0086] The arithmetic mean roughness Ra of the surface of the antifouling layer 18 is preferably in the range of 0.3 nm to 10 nm, from the viewpoint of achieving both scratch resistance and abrasion durability. More preferably, it is in the range of 0.5 nm to 5 nm, and even more preferably, 1 nm to 3 nm. Similarly, from the same viewpoint, the average inclination angle θa of the surface of the antifouling layer 18 is preferably 0.03° to 0.4°, more preferably 0.05° to 0.3°, and even more preferably 0.1° to 0.2°.

[0087] (Method of manufacturing anti-reflective film) To manufacture the anti-reflective film 10, a hard coat layer 14, a low refractive index layer 16, a primer layer 17, and an anti-fouling layer 18 should be formed in this order. To form each layer, the composition for forming each layer should be applied, dried as necessary, and then cured using a method appropriate to the curability of the composition, such as irradiation with ionizing radiation including ultraviolet light. After forming one layer, the composition for forming the next layer should be applied, dried as necessary, and then the composition should be cured. By repeating this process sequentially, a laminated structure of the hard coat layer 14, low refractive index layer 16, primer layer 17, and anti-fouling layer 18 can be formed, and the anti-reflective film 10 can be manufactured.

[0088] A wet method can be suitably used for coating the compositions that form each layer. Specifically, various coating methods such as reverse gravure coating, direct gravure coating, die coating, bar coating, wire bar coating, roll coating, spin coating, dip coating, spray coating, knife coating, and kiss coating, as well as various printing methods such as inkjet, offset printing, screen printing, and flexographic printing, can be used.

[0089] The drying process for each layer is not particularly limited as long as it removes the solvent used in the coating liquid, but it is preferable to carry it out at a temperature of 50 to 150°C for about 10 to 180 seconds.

[0090] For UV irradiation of each layer, high-pressure mercury lamps, electrodeless (microwave) lamps, xenon lamps, metal halide lamps, and other UV irradiation devices can be used. UV irradiation may be carried out under an inert gas atmosphere such as nitrogen, if necessary. The UV irradiation dose is not particularly limited, but is generally between 50 and 800 mJ / cm². 2 Preferably, 100-300 mJ / cm² 2 This is preferable.

[0091] When forming a hard coat layer 14 on the surface of the base film 12, the surface of the base film 12 may be subjected to a surface treatment before coating in order to improve the adhesion between the base film 12 and the hard coat layer 14. Examples of surface treatments include corona treatment, plasma treatment, hot air treatment, ozone treatment, and ultraviolet treatment.

[0092] (Characteristics of anti-reflective film) The anti-reflective film 10 having the above configuration comprises a base film 12, a hard coat layer 14 formed on the surface of the base film 12, a low refractive index layer 16 formed on the surface of the hard coat layer 14, a primer layer 17 formed on the surface of the low refractive index layer 16, and an anti-fouling layer 18 formed on the surface of the primer layer 17, wherein the anti-fouling layer 18 is composed of a cured product of a composition containing fluorine-containing (meth)acrylate, the fluorine-containing (meth)acrylate content in the anti-fouling layer 18 is 90% by mass or more based on the total solid content of the anti-fouling layer 18, and the thickness d of the low refractive index layer LR The thickness of the primer layer is 46 nm or greater. PR The total thickness d of the low refractive index layer 16 and primer layer 17 is 8 nm or greater. LR +d PR The wavelength is between 60 nm and 100 nm. In the anti-reflective film 10, the anti-fouling layer 18 has the above composition, and a primer layer 17 is formed between the low refractive index layer 16 and the anti-fouling layer 18. Furthermore, the thickness of the low refractive index layer 16 and the primer layer 17, and their sum, satisfy the above range, so that the anti-reflective film 10 has excellent anti-reflective properties and scratch resistance, as well as high fouling resistance and abrasion resistance.

[0093] The anti-reflective film 10 has high stain resistance, making it difficult for dirt such as fingerprints to adhere to the surface of the anti-reflective film 10, and even if it does adhere, it can be easily removed. The anti-reflective film 10 according to this embodiment is particularly excellent at removing fingerprints. In the anti-reflective film 10 according to this embodiment, the high stain resistance is thought to be due to the increased smoothness of the surface of the stain-resistant layer 18 caused by the formation of the primer layer 17. Furthermore, the high abrasion resistance is thought to be due to the high adhesion between the low refractive index layer 16 and the stain-resistant layer 18 via the primer layer 17. In addition to high anti-reflective and stain resistance, the anti-reflective film 10 according to this embodiment has high scratch resistance and abrasion resistance, making it particularly suitable for applications that are frequently touched by fingers, such as those placed on the surface of touch panels.

[0094] The haze in the anti-reflective film 10 is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.0 or less, from the viewpoint of good visibility. The luminous reflectance of the anti-reflective film 10 is preferably as low as possible, more preferably 2.5% or less, and even more preferably 2.0% or less. If the luminous reflectance is 2.0% or less, the anti-reflective film 10 can be considered to have sufficiently high anti-reflective properties.

[0095] <Other forms of anti-reflective film> As described above, the anti-reflective film according to the present invention has a hard coat layer 14, a low refractive index layer 16, a primer layer 17, and an anti-fouling layer 18 laminated in this order on the surface of a base film 10. The configuration of the anti-reflective film 10 according to the first embodiment is not limited to the above, as long as the anti-fouling layer 18 has a predetermined composition and the thicknesses of the low refractive index layer 16 and the anti-fouling layer 18, and their sum, meet predetermined ranges. Other embodiments of the anti-reflective film according to the present invention are described below as examples.

[0096] (Second embodiment) Figure 2 shows an anti-reflective film 20 according to the second embodiment. The anti-reflective film 20 according to the second embodiment includes a base film 12, a hard coat layer 14 formed on the surface of the base film 12, a high refractive index layer 15 formed on the surface of the hard coat layer 14, a low refractive index layer 16 formed on the surface of the high refractive index layer 15, a primer layer 17 formed on the surface of the low refractive index layer 16, and an anti-fouling layer 18 formed on the surface of the primer layer 17.

[0097] The anti-reflective film 20 according to the second embodiment differs from the anti-reflective film 10 according to the first embodiment in that it has a high refractive index layer 15 between the hard coat layer 14 and the low refractive index layer 16. Other than this, it is the same as the anti-reflective film 10 according to the first embodiment, and a description of the similar configuration will be omitted.

[0098] The high refractive index layer 15 is a layer having a higher refractive index than the hard coat layer 14 and the low refractive index layer 16. By providing the high refractive index layer 15 between the hard coat layer 14 and the low refractive index layer 16, the anti-reflective film 10 exhibits a higher anti-reflective effect. The refractive index of the high refractive index layer 15 is preferably in the range of 1.55 to 1.80. More preferably it is 1.60 or higher, and 1.70 or lower.

[0099] The average thickness of the high refractive index layer 15 varies depending on the refractive index setting, but for example, setting it to 50 nm to 200 nm can further enhance the anti-reflective function. The high refractive index layer 15 may be provided by stacking two or more layers with mutually different refractive indices.

[0100] (Third embodiment) Figure 3 shows an anti-reflective film 30 according to the third embodiment. The anti-reflective film 30 according to the third embodiment includes a base film 12, a hard coat layer 14 formed on one surface of the base film 12, a low refractive index layer 16 formed on the surface of the hard coat layer 14, a primer layer 17 formed on the surface of the low refractive index layer 16, and an anti-fouling layer 18 formed on the surface of the primer layer 17. It also has a transparent adhesive layer 22 on the other surface of the base film 12. A release film 24 is placed on the surface of the transparent adhesive layer 22 as needed. The release film 24 functions as a protective layer for the transparent adhesive layer 22 before use of the anti-reflective film 30 and is peeled off from the transparent adhesive layer 22 when the anti-reflective film 30 is used.

[0101] The anti-reflective film 30 according to the third embodiment differs from the anti-reflective film 10 according to the first embodiment in that it has a transparent adhesive layer 22 on the other surface of the base film 12. Other than this, it is the same as the anti-reflective film 10 according to the first embodiment, and a description of the similar configuration will be omitted.

[0102] The transparent adhesive layer 22 is for ensuring good adhesion of the anti-reflective film 30 to the surface of a display or the like. Furthermore, the presence of the transparent adhesive layer 22 of the anti-reflective film 30 has the effect of preventing the glass of the display or the like from shattering. In other words, the anti-reflective film 30 also functions as a shatterproof film.

[0103] The adhesive composition forming the transparent adhesive layer 22 may contain known adhesive resins such as acrylic adhesives, silicone adhesives, and urethane adhesives. Among these, acrylic adhesives are preferred from the viewpoint of optical transparency and heat resistance. The adhesive composition preferably contains a crosslinking agent to enhance the cohesive force of the transparent adhesive layer 22. Examples of crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, and chelate crosslinking agents.

[0104] The adhesive composition may contain additives as needed. Examples of known additives include plasticizers, silane coupling agents, surfactants, antioxidants, fillers, curing accelerators, and curing retarders. Furthermore, from the viewpoint of productivity, the composition may be diluted using organic solvents.

[0105] The thickness of the transparent adhesive layer 22 is not particularly limited, but is preferably in the range of 5 μm to 100 μm. More preferably it is 10 μm or more, and 50 μm or less.

[0106] The transparent adhesive layer 22 can be formed by methods such as directly applying the adhesive composition to the other surface of the base film 12, applying the adhesive composition to the surface of the release film 24 and then transferring it to the other surface of the base film 12, or applying the adhesive composition to the surface of the first release film, then bonding the second release film, peeling off one of the release films and transferring it to the other surface of the base film 12.

[0107] From the viewpoint of preventing glass from shattering, the transparent adhesive layer 22 preferably has an adhesive strength of 4N / 25mm or more to the glass. More preferably it is 6N / 25mm or more, and even more preferably 10N / 25mm or more.

[0108] (Fourth embodiment) Figure 4 shows an anti-reflective film 40 according to the fourth embodiment. The anti-reflective film 40 according to the fourth embodiment includes a base film 12, a hard coat layer 14 formed on one surface of the base film 12, a low refractive index layer 16 formed on the surface of the hard coat layer 14, a primer layer 17 formed on the surface of the low refractive index layer 16, an anti-fouling layer 18 formed on the surface of the primer layer 17, and a protective film 28 disposed on the surface of the anti-fouling layer 18 via an adhesive layer 26.

[0109] The anti-reflective film 40 according to the fourth embodiment differs from the anti-reflective film 30 according to the third embodiment in that it has a protective film 28 on the surface of the anti-fouling layer 18 via an adhesive layer 26. Otherwise, it is the same as the anti-reflective film 30 according to the third embodiment, and a description of the similar configuration will be omitted.

[0110] The protective film 28 can prevent scratches on the surface of the anti-fouling layer 18 when handling the anti-reflective film 40, such as during continuous processing in a roll process or when it is laminated to a display. The protective film 28 is attached to the surface of the anti-fouling layer 18 via an adhesive layer 26. After processing the anti-reflective film 40, the protective film 28 is peeled off from the surface of the anti-fouling layer 18 together with the adhesive layer 26. For this reason, the adhesive force between the protective film 28 and the adhesive layer 26 is stronger than the adhesive force between the anti-fouling layer 18 and the adhesive layer 26, and the adhesive force between the anti-fouling layer 18 and the adhesive layer 26 is adjusted to allow for interfacial peeling.

[0111] The materials constituting the protective film 28 can be appropriately selected from those exemplified as materials constituting the base film 12. The thickness of the protective film 28 is not particularly limited, but can be in the range of 2 μm to 500 μm or 2 μm to 200 μm.

[0112] As the adhesive layer 26, the one described in Patent Document 1 can be suitably applied. The adhesive forming the adhesive layer 26 is not particularly limited, and acrylic adhesives, silicone adhesives, urethane adhesives, etc., can be suitably used. In particular, acrylic adhesives are preferred because they have excellent transparency and heat resistance. The acrylic adhesive is preferably formed from an adhesive composition containing a (meth)acrylic polymer and a crosslinking agent.

[0113] (Meth)acrylic polymers are homopolymers or copolymers of (meth)acrylic monomers. Examples of (meth)acrylic monomers include alkyl group-containing (meth)acrylic monomers, carboxyl group-containing (meth)acrylic monomers, and hydroxyl group-containing (meth)acrylic monomers.

[0114] Examples of crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, metal chelate-based crosslinking agents, metal alkoxide-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, and melamine-based crosslinking agents. These crosslinking agents may be used individually or in combination of two or more.

[0115] The adhesive composition may contain other additives in addition to the (meth)acrylic polymer and crosslinking agent. Examples of other additives include crosslinking accelerators, crosslinking retarders, tackifiers, antistatic agents, silane coupling agents, plasticizers, release agents, pigments, dyes, wetting agents, thickeners, UV absorbers, preservatives, antioxidants, metal deactivators, alkylating agents, and flame retardants. These are selected and used appropriately depending on the application and intended use of the adhesive.

[0116] The thickness of the adhesive layer 26 is not particularly limited, but is preferably in the range of 1 μm to 10 μm. More preferably it is 2 μm or more, and 7 μm or less.

[0117] Although embodiments of the present invention have been described above, the present invention is not limited in any way to the above embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0118] For example, in the above embodiment, it is stated that a surface treatment may be applied to the surface of the base film 12, but instead of surface treatment, an easy-adhesion layer may be provided on the surface of the base film 12.

[0119] Furthermore, various functional layers, such as a gas barrier-enhancing layer, an antistatic layer, and an oligomer-blocking layer, may be pre-applied to the surface of the base film 12 before forming each layer. As the antistatic layer, the one described in Patent Document 1 can be suitably applied.

[0120] Furthermore, in the third embodiment described above, the transparent adhesive layer 22 and release film 24 are shown as being added to the anti-reflective film 10 of the first embodiment shown in Figure 1, as shown in Figure 3, but they may also be added to the anti-reflective film 20 of the second embodiment shown in Figure 2. Also, in the fourth embodiment described above, the adhesive layer 26 and protective film 28 are shown as being added to the anti-reflective film 30 of the third embodiment shown in Figure 3, as shown in Figure 4, but they may also be added to the anti-reflective film 10 of the first embodiment shown in Figure 1 or the anti-reflective film 20 of the second embodiment shown in Figure 2. [Examples]

[0121] The present invention will be described in detail below using examples and comparative examples. Unless otherwise specified, the preparation and evaluation of samples were carried out at room temperature in air.

[0122] <Preparation of compositions for forming a hard coat layer> To the UV-curable resin composition "ESS-620" (manufactured by DIC, urethane acrylate resin, solvent (ethyl acetate), solids content 79% by mass), the photopolymerization initiator "Omnirad127" (manufactured by IGM Resins BV) was added to a total amount of 3% by mass relative to the total amount of the hard coat layer forming composition, and ethyl acetate was added to a total solids content of 31% by mass to prepare a hard coat layer forming composition.

[0123] <Preparation of compositions for forming high refractive index layers> A composition for forming a high refractive index layer was prepared by adding methyl ethyl ketone to the UV-curable resin composition "TYZ65-01" (manufactured by Toyo Chem, acrylic resin, containing zirconium oxide (average particle size 80 nm), photopolymerization initiator, solvent (cyclohexanone, methyl isobutyl ketone, propylene glycol monomethyl ether), solids content 35% by mass) to achieve a solids content of 8% by mass.

[0124] <Preparation of a composition for forming a low refractive index layer> A composition for forming a low refractive index layer was prepared by blending a binder resin, hollow silica particles, alumina particles, a fluorine-containing compound (only for Comparative Example 8), and a photopolymerization initiator to the composition shown in Table 1 (mass %), and then adjusting the solid content concentration to the level shown in Table 1 using a solvent (MEK / PGM = 1 / 3). The materials used as components for the low refractive index layer formation composition are as follows: • Binder resin: Toagosei's "Aronics MT-3041", polyfunctional acrylate, solids content concentration 100% by mass • Hollow silica particles: JGC Catalysts & Chemicals "Thru-Ria 4320", average particle size 60 nm, solvent (MIBK), solids content concentration: 20% by mass • Alumina particles: Toyo Chem's alumina sol "RioDuras KT-110AL", 25% by mass of alumina particles (average particle size: 110 nm), 15% by mass of photosensitive monomer and resin, solvent (MEK, cyclohexanone, aliphatic solvent) • Fluorine-containing compound: Shin-Etsu Chemical Co., Ltd. "KY-1216", perfluoropolyether group-containing (meth)acrylate, solvent (MEK), solids content concentration 20% by mass • Photopolymerization initiator: "Omnirad127" as described above.

[0125] <Preparation of a composition for forming a primer layer> A primer layer-forming composition was prepared by blending a binder resin (Aronix MT-3041, mentioned above) and a photopolymerization initiator (Omnirad 127, mentioned above) to the composition shown in Table 1 (mass %), and then adjusting the solid content concentration to the one shown in Table 1 using a solvent (MEK / PGM = 1 / 3).

[0126] <Preparation of composition for forming an antifouling layer> A composition for forming an antifouling layer was prepared by blending a fluorine-containing compound ("KY-1216" above), a binder resin ("Aronics MT-3041" above; only for Comparative Example 7), and a photopolymerization initiator ("Omnirad127" above) to the blending composition (mass %) of total solids shown in Table 1, and adjusting the solids concentration to the level shown in Table 1 using a solvent (MEK / PGM = 1 / 3).

[0127] <Preparation of the hard coat layer> For each of Examples 1-8 and Comparative Examples 1-8, a hard coat layer-forming composition was applied to a base film (Toray Industries' "Lumirror #50-U403", polyethylene terephthalate film, 50 μm thick) using a #12 wire bar. After drying at 80°C for 60 seconds, a high-pressure mercury lamp was used to apply light at a intensity of 200 mJ / cm². 2 A hard coat layer (thickness 4 μm) was formed by irradiating it with ultraviolet light.

[0128] <Fabrication of high refractive index layers> For each of Examples 1-8 and Comparative Examples 1-8, a high refractive index layer-forming composition was applied to the surface of the hard coat layer, dried at 80°C for 60 seconds, and then exposed to light at a pressure of 200 mJ / cm² using a high-pressure mercury lamp under a nitrogen atmosphere. 2 A high refractive index layer (thickness 110 nm) was formed by irradiating it with ultraviolet light.

[0129] <Fabrication of low refractive index layers> For each of Examples 1-8 and Comparative Examples 1-8, the low refractive index layer-forming composition was applied to the surface of the high refractive index layer using a #3 wire bar, dried at 100°C for 60 seconds, and then exposed to light at a pressure of 200 mJ / cm² using a high-pressure mercury lamp under a nitrogen atmosphere. 2A low refractive index layer was formed by irradiation with ultraviolet light. The film thickness was as shown in Table 1.

[0130] <Preparation of the primer layer> For each of Examples 1-8 and Comparative Examples 1-5, the primer layer-forming composition was applied to the surface of the low refractive index layer using a #3 wire bar, dried at 100°C for 60 seconds, and then exposed to light at a pressure of 200 mJ / cm² using a high-pressure mercury lamp under a nitrogen atmosphere. 2 A primer layer was formed by irradiation with ultraviolet light. The film thickness was as shown in Table 1. For Comparative Examples 6-8, no primer layer was formed.

[0131] <Preparation of antifouling layer> For Examples 1-8 and Comparative Examples 1-5, the antifouling layer-forming composition was applied to the surface of the primer layer using a #3 wire bar, and for Comparative Examples 6 and 7, it was applied to the surface of the low refractive index layer using a #3 wire bar. After drying at 100°C for 60 seconds, the compositions were exposed to light at a pressure of 200 mJ / cm² using a high-pressure mercury lamp under a nitrogen atmosphere. 2 A stain-resistant layer was formed by irradiation with ultraviolet light. The film thickness was as shown in Table 1. No stain-resistant layer was formed in Comparative Example 8. Based on the above, anti-reflective films according to Examples 1-8 and Comparative Examples 1-8 were prepared.

[0132] <Evaluation Method> (Thickness and refractive index of each layer) For each sample, the thickness and refractive index of the hard coat layer, high refractive index layer, low refractive index layer, primer layer, and antifouling layer were evaluated. In this process, after each layer was formed, the thickness of each layer and the refractive index at a wavelength of 589.3 nm were calculated by curve fitting using the least squares method between the reflection spectral spectrum in the wavelength range of 380-780 nm obtained using a micro-spectroscopic film thickness meter (OPTM-F1, manufactured by Otsuka Electronics) and the theoretical spectrum derived based on Fresnel's equation.

[0133] (Luminous reflectance) The back surface of the fabricated anti-reflective film (the side opposite the low refractive index layer) was roughened with #400 grit sandpaper and painted black. The 5° specular reflectance of the surface of the low refractive index layer at wavelengths of 380 nm to 780 nm was measured using a UV-Vis-Near-Infrared spectrophotometer (Shimadzu Corporation "UV-3600"). The luminous reflectance was calculated by multiplying this measurement by the relative luminous efficiency value. If the luminous reflectance is 2.0% or less, the anti-reflective properties can be considered sufficient.

[0134] (Abrasion durability) For each sample, the abrasion resistance was evaluated by an eraser abrasion test using the water contact angle as an indicator. An eraser abrasion test was performed on each sample. A flat surface abrasion tester (DAS-400, manufactured by Daiei Kagaku Seiki Seisakusho) was used, and an eraser for the abrasion test (Minoan, cylindrical with a contact surface diameter of φ6 mm) was placed on the surface of the anti-reflective film of each sample and moved back and forth. The stroke length of the test stand was 50 mm, the reciprocating speed of the test stand was 30 reciprocations / minute, and the applied load was 1.0 kg. The water contact angle was measured every 100 reciprocations up to 500 reciprocations, and then every 500 reciprocations thereafter. The maximum number of reciprocations required to maintain a water contact angle of 90° or more was used as the evaluation value. An evaluation value of 2000 reciprocations or more indicates sufficient abrasion resistance. Furthermore, an evaluation value of 3000 reciprocations or more indicates high abrasion resistance. The water contact angle was measured using a contact angle meter (DropMaster DMo-502, manufactured by Kyowa Interface Science) by dropping 4 μL of pure water onto the surface of the anti-reflective film.

[0135] (Scratch resistance) A steel wool resistance test was performed on each sample. A flat abrasion tester (DAS-400, manufactured by Daiei Kagaku Seiki Seisakusho) was used, and steel wool #0000 (manufactured by Nippon Steel Wool Co., Ltd.), fixed to a 20mm x 20mm flat friction element, was placed on the surface of each sample's anti-reflective film and moved back and forth. The test stand stroke length was 50mm, the reciprocating speed was 60 reciprocations / minute, and the applied load was 1.5kg. 100 reciprocations were performed. Anti-reflective films with scratches of 10mm or longer after the test were evaluated as having low scratch resistance (×). Films with scratches less than 10mm in length but no scratches of 10mm or longer were evaluated as having high scratch resistance (〇). Scratches of this magnitude do not pose a practical problem. Furthermore, films with no scratches were evaluated as having very high scratch resistance (◎).

[0136] (Stain-resistant) For each sample, the ability to wipe away fingerprints was evaluated as part of the assessment of its stain resistance. A commercially available artificial fingerprint solution (manufactured by Isekyu, artificial sweat solution method A (sweat test machine method)) was applied to the fingers, rubbed into the fingers, and then the fingers were pressed against the surface of the low refractive index layer of an anti-reflective film to leave fingerprints. Next, the anti-reflective film was placed on black paper, and the fingerprints attached to the surface of the anti-reflective film were wiped off using a polyester wiper (manufactured by AS ONE, Azpure Super Wiper (Econo)) while visually observing the process. Films that could be wiped clean until the artificial fingerprint solution was no longer visible within 10 passes were evaluated as having high stain resistance (○), while those that could not be wiped clean even after 10 passes were evaluated as having low stain resistance (×).

[0137] <Evaluation Results> Table 1 shows the evaluation results for Examples 1-8 and Comparative Examples 1-8, along with the component composition (unit: mass %) of the low refractive index layer, primer layer, and antifouling layer, as well as the layer configuration of the anti-reflective film.

[0138] [Table 1]

[0139] As shown in Table 1, in Examples 1 to 8, an antifouling layer containing 90% by mass or more of fluorine-containing (meth)acrylate on a total solid content basis is formed on the surface of the low refractive index layer, with a primer layer in between. Furthermore, the thickness d of the low refractive index layer LR The thickness of the primer layer is 46 nm or more. PR The total thickness of the low refractive index layer and primer layer is d, which is 8 nm or more. LR +d PR The wavelength is between 60nm and 100nm. Correspondingly, in Examples 1 to 8, a low luminous reflectance of 2.0% or less and high abrasion resistance of 2000 cycles or more were obtained in the evaluation value. At the same time, high scratch resistance rated as "◎" or "○" and high stain resistance rated as "○" were obtained.

[0140] On the other hand, in Comparative Examples 1-3, the total thickness d of the low refractive index layer and the primer layer was LR +d PR Because it falls outside the range of 60 nm to 100 nm, the reduction effect of reflection due to optical interference cannot be sufficiently obtained, and the luminous reflectance exceeds 2.0%. Furthermore, in Comparative Example 1, the thickness d of the low refractive index layer is LR Because the particle size is less than 46nm, the wear resistance is low.

[0141] In Comparative Example 4, the thickness d PR It has a primer layer of 8 nm or more along with a low refractive index layer, with a total thickness d LR +d PR Although it is also 60nm or more, the thickness d of the low refractive index layer LR The wavelength is less than 46 nm. In this comparative example 4, the wear resistance is low, indicating that if the low refractive index layer is too thin, sufficient wear resistance cannot be obtained in the anti-reflective film.

[0142] In Comparative Example 6, where no primer layer is formed and the antifouling layer is directly formed on the surface of the low refractive index layer, both abrasion resistance and antifouling properties are lower. Abrasion resistance is significantly lower compared to Example 3, which differs only in the presence or absence of a primer layer. It is believed that the lack of a primer layer reduces adhesion between the low refractive index layer and the antifouling layer, resulting in lower abrasion resistance. Furthermore, the lack of a primer layer reduces the smoothness of the surface of the antifouling layer, preventing sufficient antifouling properties from being achieved.

[0143] In Comparative Example 5, a primer layer is formed, but its thickness d PR However, the thickness is less than 8 nm, resulting in low abrasion resistance. This indicates that if the primer layer is too thin, the effect of improving abrasion resistance through improved adhesion of the antifouling layer is not fully realized.

[0144] In Comparative Example 7, similar to Comparative Example 6, a primer layer was not provided, but instead, a fluorine-free binder resin was added to the antifouling layer. However, Comparative Example 7 showed lower abrasion resistance. The antifouling performance was also low, rated as "×," similar to Comparative Example 6. From these results, it can be concluded that adding a fluorine-free binder resin to the antifouling layer does not adequately improve adhesion with the low refractive index layer, as it would in place of a primer layer. Furthermore, it can be interpreted that the relatively lower content of fluorine-containing compounds in the antifouling layer prevents sufficient antifouling performance from being achieved.

[0145] In Comparative Example 8, no primer layer or antifouling layer was provided on the surface of the low refractive index layer. Instead, a fluorine-containing compound was added to the low refractive index layer. However, in Comparative Example 8, both abrasion resistance and antifouling properties were low. This indicates that adding a fluorine-containing compound to the low refractive index layer instead of an antifouling layer does not provide the same effect as an antifouling layer provided as an independent layer on the surface of the low refractive index layer.

[0146] As described above, the anti-reflective film comprises a base film, a hard coat layer formed on the surface of the base film, a low refractive index layer formed on the surface of the hard coat layer, a primer layer formed on the surface of the low refractive index layer, and an antifouling layer formed on the surface of the primer layer, wherein the antifouling layer is composed of a cured product of a composition containing fluorine-containing (meth)acrylate, the fluorine-containing (meth)acrylate content in the antifouling layer is 90% by mass or more based on the total solid content of the antifouling layer, and the thickness of the bottom refractive index layer d LR The thickness of the primer layer is 46 nm or more. PR The total thickness of the low refractive index layer and the primer layer is d LR +d PR By having a wavelength between 60nm and 100nm, the anti-reflective film possesses excellent anti-reflective properties and scratch resistance, as well as high stain resistance and abrasion resistance.

[0147] Although embodiments of the present invention have been described above, the present invention is not limited in any way to the above embodiments, and various modifications are possible without departing from the spirit of the present invention. [Explanation of Symbols]

[0148] 10, 20, 30, 40 Anti-reflective film 12. Base film 14. Hard court layer 15 High refractive index layer 16 Low refractive index layer 17. Primer layer 18. Anti-fouling layer 22 Transparent adhesive layer 24 Release film 26 Adhesive layer 28 protective films

Claims

1. It comprises a base film, a hard coat layer formed on the surface of the base film, a low refractive index layer formed on the surface of the hard coat layer, a primer layer formed on the surface of the low refractive index layer, and an antifouling layer formed on the surface of the primer layer. The antifouling layer is composed of a cured product of a composition containing fluorine-containing (meth)acrylate, The content of the fluorine-containing (meth)acrylate in the antifouling layer is 90% by mass or more based on the total solid content of the antifouling layer. The thickness d of the low refractive index layer ＬＲ It is 46 nm or longer. The thickness d of the primer layer ＰＲ It is 8 nm or larger, The total thickness d of the low refractive index layer and the primer layer ＬＲ +d ＰＲ An anti-reflective film with a wavelength between 60 nm and 100 nm.

2. The low refractive index layer is composed of a cured product of a composition comprising a binder resin containing a (meth)acrylate compound, inorganic oxide particles, and hollow silica particles. The anti-reflective film according to claim 1, wherein the primer layer is composed of a cured product of a composition containing a binder resin containing a (meth)acrylate compound and free from particles made of inorganic oxides.

3. The anti-reflective film according to claim 2, wherein the binder resin contained in the primer layer is the same as the binder resin contained in the low refractive index layer.

4. The anti-reflective film according to claim 2 or claim 3, wherein the low refractive index layer does not contain a fluorine-containing compound.

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