Antireflection film and method for producing antireflection film

Abstract

To provide an antireflection film that has both high antireflection properties and superior scratch resistance, and that is capable of acquiring high antifouling property without relying on fluorine-containing compounds, as well as a method for producing such an antireflection film.SOLUTION: An antireflection film 10 comprises: a base film 12; a hard coat layer 14 formed on a surface of the base film 12; and an optical functional layer 16 formed on a surface of the hard coat layer 14. The optical functional layer 16 is formed from a cured product of an ionizing radiation-curable composition that contains a polyfunctional (meth)acrylate compound having a reactive group, and an amino-modified organopolysiloxane, where at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and that further contains alumina particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an antireflection film and a method for producing an antireflection film, and more particularly to an antireflection film suitable for use on the surfaces of displays such as liquid crystal displays, organic EL displays, and touch panels of smartphones and the like, and a method for producing such an antireflection film. [Background technology]

[0002] An anti-reflection film may be disposed on the display surface of a liquid crystal display, an organic electroluminescence display, a touch panel of a smartphone, etc., in order to prevent reflection of external light on the screen. As an anti-reflection film, one having a hard coat layer and an optical functional layer in this order on a substrate film is known. The characteristics required for an anti-reflection film include optical characteristics such as low reflectance and high transmittance, and physical characteristics such as high hardness, scratch resistance, and anti-fouling properties. As an anti-reflection film having anti-fouling properties, for example, one having a high refractive index layer and a low refractive index layer on a substrate film, and containing a fluorine-containing compound in the low refractive index layer (Patent Document 1), one containing an anti-fouling layer made of a fluorine-containing compound on the surface of the low refractive index layer (Patent Document 2), one containing a silicone compound in the low refractive index layer (Patent Document 3), etc. are disclosed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-148805 A [Patent Document 2] JP 2021-152654 A [Patent Document 3] JP 2011-154177 A Summary of the Invention [Problem to be solved by the invention]

[0004] Although the fluorine-containing compounds used in Patent Document 1 and Patent Document 2 are effective in improving the antifouling properties, some of the compounds belonging to the group of perfluoroalkyl compounds and polyfluoroalkyl compounds (PFAS) are restricted substances under the European REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulation due to concerns about environmental burden and health hazards, and the regulations are expected to become stricter in the future. Currently, the main targets of regulations are fluorine-containing compounds having long-chain perfluoroalkyl groups such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), but against this background, it is desirable not to use not only compounds having long-chain perfluoroalkyl groups but also fluorine-containing compounds having fluoroalkyl groups in general in materials used for displays. The anti-reflection film of Patent Document 3 uses a silicone compound as an antifouling agent and does not contain a fluorine-containing compound, but it is difficult to effectively improve scratch resistance by simply adding a silicone compound as an antifouling agent.

[0005] The problem to be solved by the present invention is to provide an antireflection film that has high antireflection properties and excellent scratch resistance, and can impart high antifouling properties without relying on a fluorine-containing compound, and a method for producing such an antireflection film. [Means for solving the problem]

[0006] In order to solve the above problems, the anti-reflection film according to the present invention has the following configuration. [1] The antireflection film according to the present invention comprises a substrate film, a hard coat layer formed on a surface of the substrate film, and an optical functional layer formed on the surface of the hard coat layer, the optical functional layer being formed from a cured product of an ionizing radiation-curable composition which contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, at least a portion of the polyfunctional (meth)acrylate compound and at least a portion of the amino-modified organopolysiloxane forming an addition reaction product, and further contains alumina particles which have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound.

[0007] [2] In the above aspect [1], the optical functional layer may not contain a fluorine-containing compound having a fluoroalkyl group.

[0008] [3] In the above embodiment [1] or [2], the antireflection film may include a high refractive index layer and a low refractive index layer in this order on a surface of the hard coat layer, the low refractive index layer being composed of the optical functional layer, and the high refractive index layer may have a refractive index at a wavelength of 550 nm higher than that of the hard coat layer and higher than that of the low refractive index layer.

[0009] [4] In any one of the above aspects [1] to [3], the low refractive index layer may contain silica particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound.

[0010] [5] In the method for producing an antireflection film according to the present invention, when producing an antireflection film having a base film, a hard coat layer formed on a surface of the base film, and an optical functional layer formed on a surface of the hard coat layer, the optical functional layer is formed by applying an ionizing radiation-curable composition containing a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, in which at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and further containing alumina particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound, onto a surface of the hard coat layer, and curing the composition by exposure to ionizing radiation. Effect of the Invention

[0011] The antireflection film according to the present invention has a base film, a hard coat layer formed on a surface of the base film, and an optical functional layer formed on the surface of the hard coat layer, and the optical functional layer is formed from a cured product of an ionizing radiation-curable composition that contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, in which at least a portion of the polyfunctional (meth)acrylate compound and at least a portion of the amino-modified organopolysiloxane form an addition reaction product, and further contains alumina particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound. Therefore, the antireflection film has high antifouling properties while having excellent scratch resistance as well as high antireflection properties, without relying on a fluorine-containing compound.

[0012] In addition, in the method for producing an antireflection film according to the present invention, when producing an antireflection film having a base film, a hard coat layer formed on a surface of the base film, and an optical functional layer formed on a surface of the hard coat layer, the optical functional layer contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and further contains alumina particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound, and the optical functional layer is formed by applying an ionizing radiation-curable composition onto the surface of the hard coat layer and curing the composition by irradiation with ionizing radiation. Therefore, the produced antireflection film has high antireflection properties and excellent scratch resistance, and can be imparted with high antifouling properties without relying on a fluorine-containing compound. [Brief description of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view of an antireflection film according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of an antireflection film according to a second embodiment of the present invention. [Diagram 3] FIG. 4 is a cross-sectional view of an antireflection film according to a third embodiment of the present invention. [Figure 4] FIG. 11 is a cross-sectional view of an antireflection film according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described in detail below. In this specification, various physical properties refer to values ​​at room temperature and in the atmosphere unless otherwise specified. In addition, in this specification, the refractive index of a substance and a substance layer refers to a refractive index at a measurement wavelength of 550 nm unless otherwise specified.

[0015] <Anti-reflection film of the first embodiment> Fig. 1 is a cross-sectional view of an antireflection film according to a first embodiment of the present invention. As shown in Fig. 1, an antireflection film 10 according to a first embodiment of the present invention has a base film 12, a hard coat layer 14 formed on the surface of the base film 12, and an optical functional layer 16 formed on the surface of the hard coat layer 14. In this embodiment, the above layers are laminated in order without any other layer therebetween. The optical functional layer 16 is the layer exposed on the outermost surface of the antireflection film 10 as a whole.

[0016] (Base film) The base film 12 is not particularly limited as long as it has transparency. Examples of the base film 12 include a transparent polymer film and a glass film. Transparency means that the total light transmittance in the visible light wavelength region is 50% or more, and the total light transmittance is more preferably 85% or more. The 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 is preferably in the range of 2 μm to 500 μm in terms of excellent handleability, etc. More preferably, it is in the range of 2 μm to 200 μm. Note that, although the term "film" generally refers to a film having a thickness of less than 0.25 mm, if a film having a thickness of 0.25 mm or more can be wound into a roll, the film is also considered to be a film having a thickness of 0.25 mm or more.

[0017] Examples of the polymeric material of 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, polypropylene resin, polyethylene resin, polycycloolefin resin, cycloolefin copolymer resin, and other polyolefin resins, cellulose-based resins such as triacetyl cellulose resin and diacetyl cellulose resin, polyphenylene sulfide resin, polyvinyl chloride resin, polyvinylidene chloride resin, and polyvinyl alcohol resin. The polymeric material of the base film 12 may be composed of only one of these materials, or may be composed of a combination of two or more of these materials. Among these materials, polyethylene terephthalate resin, polyimide resin, polycarbonate resin, poly(meth)acrylate resin, polycycloolefin resin, cycloolefin copolymer resin, and triacetyl cellulose resin are more preferable from the viewpoints of optical properties and durability.

[0018] The base film 12 may be composed of a single layer containing one or more of the above-mentioned polymeric materials, or may be composed of two or more layers, such as a layer containing one or more of the above-mentioned polymeric materials and a layer containing one or more of a different polymeric material.

[0019] (Hard coat layer) The hard coat layer 14 contributes to improving the scratch resistance of the anti-reflection 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. The ionizing radiation means electromagnetic waves or charged particle beams having an energy quantum capable of polymerizing or crosslinking molecules. Examples of the ionizing radiation include ultraviolet rays (UV), X-rays, gamma rays, and other electromagnetic waves, electron beams (EB), alpha rays, ion beams, and other charged particle beams. Among these, ultraviolet rays (UV) are particularly preferred from the viewpoint of productivity. Hereinafter, the ionizing radiation curable composition may be simply referred to as a curable composition. In addition, 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". The "(meth)acrylate compound" is a compound having a (meth)acryloyl group, and examples of such compounds include monomers, oligomers, prepolymers, etc. Hereinafter, the (meth)acrylate compound may be simply referred to as (meth)acrylate.

[0020] The (meth)acrylate may be a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate. Alternatively, the (meth)acrylate may be a combination of a monofunctional (meth)acrylate and a polyfunctional (meth)acrylate. From the viewpoint of improving curability, it is more preferable that the curable composition contains a polyfunctional (meth)acrylate as the (meth)acrylate.

[0021] Examples of (meth)acrylates include urethane (meth)acrylates, silicone (meth)acrylates, alkyl (meth)acrylates, and aryl (meth)acrylates. Among these, urethane (meth)acrylates, particularly urethane (meth)acrylate oligomers, are preferred. Specific examples of urethane (meth)acrylates 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 products, adduct modified products, and biuret modified products. Examples of the hydroxyl group-containing (meth)acrylate compound include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane diacrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and their polyoxyalkylene modified products and polylactone modified products. Examples of the polyol compound include ethylene glycol, propylene glycol, butanediol, hexanediol, polyoxyethylene glycol, polyoxypropylene glycol, glycerin, trimethylolpropane, pentaerythritol, biphenol, bisphenol, and the like. When the curable composition for forming the hard coat layer 14 contains urethane (meth)acrylate as the ultraviolet curable resin, the hard coat layer 14 has a suitable flexibility, so that the anti-reflection film 10 has high bending resistance, and can be suitably used for flexible displays that are repeatedly bent, such as foldable displays and rollable displays. Furthermore, even if the base film 12 is made of, for example, polycycloolefin or cycloolefin copolymer, which is relatively prone to cracking, cracking of the base film 12 is easily prevented.

[0022] It is preferable that the (meth)acrylate constituting the curable composition further contains a pentaerythritol (meth)acrylate compound.Specific examples of the pentaerythritol (meth)acrylate compound 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.In particular, it is preferable that the curable composition contains pentaerythritol tri(meth)acrylate.

[0023] The curable composition forming the hard coat layer 14 may or may not contain a non-UV curable resin in addition to the UV curable resin. The curable composition forming the hard coat layer 14 may also contain a photopolymerization initiator. If necessary, the curable composition may also contain additives that can be generally added to the curable composition. Examples of additives include dispersants, leveling agents, defoamers, thixotropic agents, antifouling agents, antibacterial agents, flame retardants, slip agents, antistatic agents, inorganic particles, and resin particles. If necessary, the curable composition may also contain a solvent.

[0024] Examples of non-UV curable resins include thermoplastic resins, thermosetting resins, etc. Examples of thermoplastic resins include polyester resins, polyether resins, polyolefin resins, polyamide resins, etc. Examples of thermosetting resins include unsaturated polyester resins, epoxy resins, alkyd resins, phenolic resins, etc.

[0025] Examples of the photopolymerization initiator include alkylphenone-based, acylphosphine oxide-based, and oxime ester-based photopolymerization initiators. Examples of the alkylphenone-based photopolymerization initiator include 2,2'-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and the like. Examples of the acylphosphine oxide photopolymerization initiator 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 the oxime ester photopolymerization initiator include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), etc. The photopolymerization initiator may be used alone or in combination of two or more of them.

[0026] The content of the photopolymerization initiator is preferably in the range of 0.1% by mass to 10% by mass, more preferably 1% by mass to 5% by mass, based on the total solid content of the curable composition.

[0027] The inorganic particles and resin particles can be added to the hard coat layer 14 for the purpose of, for example, preventing blocking of the hard coat layer 14, adjusting the refractive index of the hard coat layer 14, etc. The inorganic particles or resin particles added form fine surface irregularities in the hard coat layer 14, which makes it easier to prevent blocking, which occurs when the hard coat film consisting of the base film 12 and the hard coat layer 14 before the optical functional layer 16 is formed, is wound into a roll.

[0028] Examples of inorganic particles capable of adjusting the refractive index of the hard coat layer 14 include metal oxide particles made of oxides of metals such as titanium, zirconium, tin, zinc, silicon, niobium, aluminum, chromium, magnesium, germanium, gallium, antimony, and platinum. These may be used alone as inorganic particles capable of adjusting the optical properties, or two or more types may be used in combination. Among these, titanium oxide and zirconium oxide are particularly preferred from the viewpoint of achieving both a high refractive index and excellent transparency. Examples of resin particles include resin particles made of 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 alone as resin particles, or two or more types may be used in combination.

[0029] 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, and more preferably 0.75 μm or more. Also, from the viewpoint of easily suppressing curling due to the difference in thermal shrinkage from the base film 12, it is preferably 20 μm or less, and more preferably 10 μm or less. The thickness of the hard coat layer 14 is the thickness of a relatively smooth portion in the thickness direction that is free of irregularities due to inorganic particles or resin particles.

[0030] From the viewpoint of suppressing interference unevenness caused by the difference in refractive index between the base film 12 and the hard coat layer 14, the refractive index of the hard coat layer 14 is preferably within the range of 1.49 to 1.56. The arithmetic mean roughness Ra of the surface of the hard coat layer 14 on which the surface irregularities are formed is preferably within a range of 0.3 nm to 20 nm, more preferably 0.5 nm to 10 nm, from the viewpoint of suppressing blocking.

[0031] Examples of the solvent used in the curable composition 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 may be used alone or in combination of two or more.

[0032] The solid content concentration of the curable composition (concentration of components other than the solvent) may be appropriately determined in consideration of coating properties, film thickness, etc. For example, it may be 1% by mass to 90% by mass, 1.5% by mass to 80% by mass, or 2% by mass to 70% by mass. Unlike the optical functional layer 16 described below, the hard coat layer 14 preferably does not contain amino-modified organopolysiloxane or its reaction product. If the hard coat layer 14 contains amino-modified organopolysiloxane or its reaction product, the adhesion of the layer formed on the hard coat layer 14 (here, the optical functional layer 16) may be deteriorated.

[0033] (optical functional layer) In the antireflection film 10 according to this embodiment, an optical functional layer 16 is provided on the surface of the hard coat layer 14. The optical functional layer 16 is a layer having a function of adjusting the optical properties of the antireflection film 10, such as refraction properties and reflection properties, and the type of the optical functional layer 16 is not particularly limited. In this embodiment, the optical functional layer 16 is a low refractive index layer adjusted to a low refractive index. The optical functional layer 16 as a low refractive index layer exerts an antireflection effect by utilizing the optical interference effect of reflected light caused by the difference in refractive index between the optical functional layer 16 and adjacent layers such as air and the hard coat layer 14.

[0034] The optical functional layer 16 is formed from a cured product of an ionizing radiation curable composition, which contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, and at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and further contains alumina particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound. As described above for the hard coat layer 14, ionizing radiation includes various electromagnetic waves and charged particle beams, but the optical functional layer 16 is preferably composed of a cured product of an ultraviolet (UV) curable composition. A suitable composition of the composition will be described below.

[0035] (1) Polyfunctional (meth)acrylate compound having a reactive group Examples of the polyfunctional (meth)acrylate compound having a reactive group include urethane (meth)acrylate, silicone (meth)acrylate, alkyl (meth)acrylate, and aryl (meth)acrylate. The (meth)acrylate compound may have only a (meth)acryloyl group as a reactive group, or may have another reactive group in addition to the (meth)acryloyl group. The reactive group is preferably an ionizing radiation reactive group, particularly an ultraviolet reactive group. Examples of the ultraviolet reactive group other than the (meth)acryloyl group include carbon-carbon unsaturated double bond groups such as vinyl groups, styryl groups, and allyl groups, and ring-opening polymerizable groups such as epoxy groups and oxetanyl groups. The polyfunctional (meth)acrylate compound refers to a compound having a plurality of such reactive groups in one molecule, and particularly preferably has a plurality of (meth)acryloyl groups.

[0036] Examples of the polyfunctional (meth)acrylate include a bifunctional (meth)acrylate, a trifunctional (meth)acrylate, a tetrafunctional (meth)acrylate, etc. More specifically, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc. 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.

[0037] The (meth)acrylate compound contained in the curable composition may be composed of one kind of the above-mentioned (meth)acrylate alone or two or more kinds. From the viewpoint of improving scratch resistance, the (meth)acrylate compound contained in the curable composition preferably contains a polyfunctional (meth)acrylate having five or more functional groups, and it is also preferable to increase the content of the polyfunctional (meth)acrylate having five or more functional groups.

[0038] In addition, the polyfunctional (meth)acrylate preferably contains a dimer. The dimer of the polyfunctional (meth)acrylate has an excellent curing speed and can easily increase the curing rate of the curable composition, so that the scratch resistance can be further improved. Among them, it is preferable to contain 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 contain at least one selected from the group consisting of dimers of pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

[0039] From the viewpoints of scratch resistance, transparency, and solubility in a solvent, the content of the dimer is preferably in the range of 25% by mass to 50% by mass, more preferably 30% by mass to 40% by mass, based on the total solid content of the polyfunctional (meth)acrylate.

[0040] (2) Amino-modified organopolysiloxane The amino-modified organopolysiloxane contained in the optical functional layer 16 imparts antifouling properties to the antireflection film.

[0041] An amino-modified organopolysiloxane has a polysiloxane skeleton consisting of repeating structural units of (-Si-O-), and at least a portion of the alkyl chains bonded as side chains to silicon atoms in the polysiloxane skeleton are modified with a substituent having an amino group (amino group-containing group). The amino group-containing group is not particularly limited, and examples thereof include a monoamino group represented by the following formula (1-1) and a diamino group represented by the following formula (1-2). The amino groups constituting the amino group-containing group may be primary amino groups or secondary amino groups, but R 2 is preferably a primary amino group in which R is a hydrogen atom. [ka] (In the formula, R 1 each independently represents an alkylene group; R 2 represents a hydrogen atom or an alkyl group.

[0042] R 1 The alkyl group and R 2 The alkylene group of R preferably has 1 to 6 carbon atoms. 1 The alkylene group having 1 to 6 carbon atoms is not particularly limited, and examples thereof include a methylene group, an ethylene group, a propylene group, and a butylene group. 2 The alkyl group having 1 to 6 carbon atoms is not particularly limited, but examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.

[0043] R 2 When R is a hydrogen atom, the monoamino group represented by formula (1-1) has a primary amino group at the terminal, such as a 3-aminopropyl group. The diamino group represented by formula (1-2) has a secondary amino group in the chain and a primary amino group at the terminal, such as an aminoethylaminopropyl group. 2 When is an alkyl group, the monoamino group represented by formula (1-1) has one secondary amino group, and the diamino group represented by formula (1-2) has two secondary amino groups.

[0044] The amino-modified organopolysiloxane may have any of a linear structure, a branched structure, and a cyclic structure, and may have a structure in which a linear structure and a cyclic structure are combined, or a structure in which a branched structure and a cyclic structure are combined. Among these, a linear structure is preferred from the viewpoint of handling as a liquid.

[0045] The bonding position of the amino group-containing group in the amino-modified organopolysiloxane is not particularly limited, and may be a terminal or a side chain, or may be a terminal and a side chain. When the amino group-containing group is present in the side chain, the amino-modified organopolysiloxane has, for example, a structural unit represented by the following general formula (2-1) or (2-2). When the amino group-containing group is present in the terminal, the amino-modified organopolysiloxane has, for example, a terminal structure represented by the following general formula (2-3). Furthermore, the amino-modified organopolysiloxane may contain a structural unit to which an amino group-containing group is not bonded in the structure, and an example of the structural unit to which an amino group-containing group is not bonded is a structural unit represented by the following general formula (2-4). The structural units contained in the amino-modified organopolysiloxane are not limited to the following. For example, when the amino-modified organopolysiloxane has a branched structure, it may contain a branched structural unit in the middle in addition to linear structural units such as those of formulas (2-1), (2-2), and (2-4) and terminal structural units such as (2-3). When the amino-modified organopolysiloxane has a cyclic structure, it does not necessarily have to contain a terminal structure such as (2-3). [ka] (In the formula, each X independently represents an amino group-containing group; R 3 each independently represents a substituted or unsubstituted hydrocarbon group preferably having 1 to 12 carbon atoms, and m represents an integer of 1 to 3.

[0046] R 3The substituted or unsubstituted hydrocarbon group represented by the formula (I) is not particularly limited, and examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, and dodecyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group, tolyl group, xylyl group, and naphthyl group; aralkyl groups such as benzyl group, 2-phenylethyl group, and 2-phenylpropyl group; and halogenated alkyl groups such as chloromethyl group and 3-chloropropyl group.

[0047] Of the linear, branched, and cyclic amino-modified organopolysiloxanes, from the viewpoint of curability, organopolysiloxanes having a linear structure with amino group-containing groups at the terminals or side chains are preferred, and organopolysiloxanes having a linear structure with amino group-containing groups at both terminals are particularly preferred.

[0048] The functional group equivalent (amino equivalent) of the amino-modified organopolysiloxane is preferably 50 eq or more and 10,000 eq or less, more preferably 200 eq or more and 3,000 eq or less, and further preferably 400 eq or more and 1,000 eq or less. If the functional group equivalent is within the above range, the optical functional layer 16 can have good antifouling properties and slipperiness.

[0049] The amino-modified organopolysiloxane preferably has a kinematic viscosity of 2 mm at 25°C. 2 / s or more 2000mm 2 / s or less, preferably 8 mm 2 / s or more 600mm 2 / s or less, and more preferably 12 mm 2 / s or more 100mm 2 If the kinetic viscosity is within the above range, the composition can be dissolved well in a solvent, and the stain resistance of the optical functional layer 16 can be easily improved.

[0050] (3) Synthesis of addition reaction products The addition reaction product of a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane can be obtained by addition reaction of an amino group contained in an amino-modified organopolysiloxane with a (meth)acryloyl group contained in a polyfunctional (meth)acrylate compound having a reactive group. As the addition reaction, a Michael addition reaction can be suitably used. An example of the addition reaction is shown in the following formula (3) when a terminal primary amino group of an amino-modified organopolysiloxane is added to an acryloyl group of an acrylate compound. [ka]

[0051] By incorporating the amino-modified organopolysiloxane in the optical functional layer 16 in a state in which an addition reaction product has been formed in advance with a polyfunctional (meth)acrylate compound, this exhibits a high effect in improving the antifouling properties of the antireflection film 10, and also exhibits a high effect in improving the scratch resistance of the antireflection film 10, compared to when the amino-modified organopolysiloxane is incorporated in the optical functional layer 16 without forming an addition reaction product. This is because by forming the addition reaction product in advance, the amino-modified organopolysiloxane is reliably incorporated in the polymer containing the polyfunctional (meth)acrylate compound in the cured product formed through curing with ionizing radiation.

[0052] The reaction conditions for Michael addition of the amino group contained in the amino-modified organopolysiloxane to the (meth)acryloyl group contained in the polyfunctional (meth)acrylate compound are not particularly limited. Specifically, for example, the polyfunctional (meth)acrylate compound having a reactive group and the amino-modified organopolysiloxane are mixed in a solvent at a temperature range from room temperature to the reflux temperature of the solvent for 1 minute to 20 hours.

[0053] The solvent used in the Michael addition reaction preferably contains alcohol such as methanol, ethanol, isopropyl alcohol, butanol, isobutyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, and triethylene glycol monomethyl ether. Examples of the solvent other than alcohol include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, octane, and heptane, organic chlorine solvents such as chloroform, methylene chloride, trichloroethylene, and carbon tetrachloride, and fatty acid esters such as ethyl acetate, butyl acetate, and isobutyl acetate. The solvent may be alcohol alone or a mixture of alcohol and another solvent. In addition, two or more types of alcohol and another solvent may be used in combination. The content of alcohol is preferably in the range of 10 to 90% by mass, more preferably 30 to 70% by mass, based on the total amount of the solvent.

[0054] A catalyst is usually not required for the Michael addition reaction between an amino group and a (meth)acryloyl group, but if one is used, a basic compound can be mentioned as the catalyst. Examples of the basic compound include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal alkoxides such as sodium methoxide and potassium ethoxide, quaternary ammonium hydroxides such as tetrabutylammonium hydroxide and benzyltrimethylammonium hydroxide, quaternary ammonium carbonates such as tetrabutylammonium carbonate, benzyltrimethylammonium carbonate, triethylmonomethylammonium 2-ethylhexanoate and tetrabutylammonium acetate, quaternary ammonium fluorides such as tetrabutylammonium fluoride and benzyltrimethylammonium fluoride, quaternary ammonium tetrahydroborates such as tetrabutylammonium tetrahydroborate and benzyltrimethylammonium tetrahydroborate, tertiary amines such as tetramethylguanidine, 1,8-diazabicyclo[5,4,0]undecene-7 and diazabicyclo[4,3,0]nonene-5, and tertiary phosphines such as guanidine, azine and triphenylphosphine.

[0055] In the curable composition constituting the optical functional layer 16, at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane may form an addition reaction product, and unreacted components that do not form an addition reaction product may be present in part in both the polyfunctional (meth)acrylate compound and the amino-modified organopolysiloxane. In other words, at least a part of the amino-modified organopolysiloxane and the polyfunctional (meth)acrylate compound may not form an addition reaction product with each other.

[0056] The content of the amino-modified organopolysiloxane in the curable composition, as the total amount of the components undergoing the addition reaction and the unreacted components, is preferably 1% by mass or more based on the total solid content of the amino-modified organopolysiloxane and the polyfunctional (meth)acrylate compound. If it is 1% by mass or more, the stain resistance of the optical functional layer 16 can be improved, and the slipperiness is improved, thereby improving the scratch resistance. From this viewpoint, the content is more preferably 3% by mass or more, and even more preferably 5% by mass or more. On the other hand, the content of the amino-modified organopolysiloxane is preferably 25% by mass or less. If it is 25% by mass or less, the scratch resistance of the optical functional layer 16 can be excellent. From this viewpoint, the content is more preferably 23% by mass or less, and even more preferably 20% by mass or less.

[0057] The molar ratio of the amino group of the amino-modified organopolysiloxane to the (meth)acryloyl group of the polyfunctional (meth)acrylate (molar amount of amino group / molar amount of (meth)acryloyl group) is preferably 0.001 to 0.5, more preferably 0.005 to 0.4, and even more preferably 0.01 to 0.2. If the molar ratio is within the above range, the scratch resistance and antifouling properties of the optical functional layer 16 can be improved.

[0058] (4) Alumina particles The curable composition constituting the optical functional layer 16 further contains alumina particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with a polyfunctional (meth)acrylate compound. The alumina particles form convex portions on the surface of the optical functional layer 16 by being contained in the optical functional layer 16. The alumina particles form convex portions on the surface of the optical functional layer 16, so that the optical functional layer 16 can have good scratch resistance.

[0059] The alumina particles may be solid particles or hollow particles, but the alumina particles are preferably solid particles. The solid particles are particles that have substantially no cavities inside the particles, and the ratio of the cavities is less than 5% of the volume of the solid particles. The hollow particles are particles that have cavities inside the particles, and the ratio of the cavities is 5% or more of the volume of the hollow particles. When the alumina particles are solid particles, the scratch resistance of the optical functional layer 16 is improved, and the scratch resistance of the anti-reflection film 10 is improved. On the other hand, when the alumina particles are hollow particles, the refractive index of the optical functional layer 16 can be lowered to reduce light reflection. In the hollow particles, the ratio of the cavities is preferably 10% or more and 80% or less of the volume of the hollow particles. When the ratio of the cavities is 10% or more, the refractive index can be lowered to reduce light reflection. It is more preferably 20% or more, and even more preferably 30% or more. On the other hand, when the ratio of the cavities is 80% or less, the decrease in dispersibility of the alumina particles can be suppressed. More preferably, it is 60% or less.

[0060] The shape of the alumina particles is not particularly limited, and may be spherical, needle-like, scaly, rod-like, fibrous, amorphous, etc. Of these, the spherical shape is preferred.

[0061] The alumina particles are surface-treated with a silane coupling agent having a reactive group capable of forming a bond with a polyfunctional (meth)acrylate compound contained in the curable composition. The silane coupling agent has a reactive group capable of forming a bond with a (meth)acrylate compound, so that the alumina particles surface-treated with the silane coupling agent can be firmly bonded to the polyfunctional (meth)acrylate contained in the optical functional layer 16 and its addition reaction product, and further bonded to reactive groups contained in adjacent layers such as the hard coat layer 14. When these bonds are formed, the scratch resistance of the anti-reflection film 10 is improved.

[0062] Silane coupling agents generally have a hydrolyzable group and other functional groups bonded to silicon atoms in the molecule. Here, the hydrolyzable group refers to a substituent that is directly bonded to a silicon atom and can generate a siloxane bond by hydrolysis and / or condensation. Examples of the hydrolyzable group include a halogen atom, an alkoxy group, an acyloxy group, and an alkenyloxy group. When the hydrolyzable group has carbon atoms, the number of carbon atoms is preferably 6 or less, and more preferably 4 or less. In particular, an alkoxy group having 4 or less carbon atoms or an alkenyloxy group having 4 or less carbon atoms is preferred. The hydrolyzable group is hydrolyzed to form a bond with an oxygen atom on the surface of the alumina particle, and the alumina particle is surface-treated.

[0063] The silane coupling agent used here contains a reactive group capable of forming a bond with a (meth)acrylate compound in addition to the hydrolyzable group. Examples of the reactive group include carbon-carbon unsaturated double bond groups such as (meth)acryloyl group, vinyl group, styryl group, and allyl group, and ring-opening polymerizable groups such as epoxy group and oxetanyl group. These reactive groups have ultraviolet ray reactivity. In the optical functional layer 16 containing a (meth)acrylate compound having a reactive group and alumina particles surface-treated with a silane coupling agent having a reactive group, the reactive group of the (meth)acrylate compound reacts with the reactive group of the silane coupling agent to form a bond.

[0064] Examples of silane coupling agents having a carbon-carbon unsaturated double bond group as a reactive group include p-styryltrimethoxysilane, 2-(allyloxymethyl)acrylate (trimethoxysilyl)propyl, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, p-styryltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and 7-octenyltrimethoxysilane.

[0065] Examples of silane coupling agents having a ring-opening polymerizable group as a reactive group include 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 8-glycidoxyoctyltrimethoxysilane.

[0066] Among these, from the viewpoint of reactivity with a (meth)acrylate compound, it is preferable to use a silane coupling agent having a carbon-carbon unsaturated double bond group, and among these, a silane coupling agent having an ethylenic carbon-carbon double bond group such as a (meth)acryloyl group, a vinyl group, a styryl group, an allyl group, etc. is particularly preferable.

[0067] The content of the silane coupling agent is preferably in the range of 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the alumina particles. This enhances the effect of the surface treatment by the silane coupling agent. In addition, the scratch resistance of the optical functional layer 16 can be maintained at a high level, and the wear resistance and solvent resistance can be improved. More preferably, the content is 10 parts by mass or more and 40 parts by mass or less. In the optical functional layer 16, the silane coupling agent that is not bonded to the alumina particles may remain, and the preferred content range described here refers to the content of the silane coupling agent as a whole, including the silane coupling agent that is not bonded to the alumina particles.

[0068] Alumina particles surface-treated with a silane coupling agent (hereinafter sometimes simply referred to as "alumina particles") form convex portions on the surface of the optical functional layer 16, and in order to obtain good scratch resistance, the difference (rd) between the average particle diameter r of the alumina particles and the thickness d of the optical functional layer 16 is preferably 10 nm or more. The difference (rd) 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 convex portions to maintain transparency, the difference (rd) is 300 nm or less. More preferably, it is 200 nm or less, and even more preferably 100 nm or less.

[0069] The average particle diameter r of the alumina particles depends on the thickness d of the optical functional layer 16, but is preferably within the range of 60 nm to 400 nm. It is more preferably 70 nm or more, and even more preferably 90 nm or more. It is more preferably 300 nm or less, and even more preferably 200 nm or less. The average particle diameter r of the alumina particles is a volume-based average arithmetic value obtained by a 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 an aggregate of particles.

[0070] The content of the alumina particles in the optical functional layer 16 is preferably 0.1% by mass or more and 6.0% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16. When the content of the alumina particles in the optical functional layer 16 is 0.1% by mass or more with respect to 100% by mass of the solid content of the optical functional layer 16, excellent scratch resistance can be obtained. From this viewpoint, the content of the alumina particles in the optical functional layer 16 is more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more with respect to 100% by mass of the solid content of the optical functional layer 16. When the content of the alumina particles in the optical functional layer 16 is 6.0% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16, high transparency can be obtained. From this viewpoint, the content of the alumina particles in the optical functional layer 16 is more preferably 5.5% by mass or less, and even more preferably 5.0% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16.

[0071] As described above, the optical functional layer 16 of the anti-reflection film 10 according to this embodiment is formed from a cured product of an ionizing radiation curable composition that contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, in which at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and further contains alumina particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound. The curable composition that constitutes the optical functional layer 16 may appropriately contain components other than the polyfunctional (meth)acrylate compound, the amino-modified organopolysiloxane, and the alumina particles. Examples of such components include silica particles and those shown below as "other components".

[0072] (5) Silica particles The optical functional layer 16 may contain silica particles. The silica particles are particles having an average particle diameter smaller than the average thickness d of the optical functional layer 16. The silica particles are preferably particles having an average particle diameter smaller than the alumina particles that form convex portions on the surface of the optical functional layer 16. The silica particles are particles that do not substantially contribute to the formation of the surface unevenness of the optical functional layer 16.

[0073] The silica particles may be solid particles or hollow particles, or may be a combination of solid particles and hollow particles. A solid particle is a particle that does not have a substantial cavity inside the particle, and the ratio of the cavity is less than 5% of the volume of the solid particle. A hollow particle is a particle that has a cavity inside the particle, and the ratio of the cavity is 5% or more of the volume of the hollow particle. When the silica particles are solid particles, the refractive index of the optical functional layer 16 can be lowered to reduce light reflection, and the scratch resistance is improved, and the scratch resistance of the anti-reflection film 10 is improved. When the silica particles are hollow particles, the refractive index of the optical functional layer 16 can be further lowered to reduce light reflection. In the hollow particles, the ratio of the cavity is preferably 10% or more and 80% or less of the volume of the hollow particle. When the ratio of the cavity is 10% or more, the refractive index can be lowered to reduce light reflection. It is more preferably 20% or more, and even more preferably 30% or more. On the other hand, if the ratio of the cavities is 80% or less, the decrease in dispersibility of the silica particles can be suppressed. More preferably, it is 60% or less. The shape of the silica particles is not particularly limited, but is preferably spherical, spindle-shaped, egg-shaped, flat, cubic, amorphous, etc. Among these, spherical, flat, cubic, etc. are particularly preferred.

[0074] The average particle diameter of the silica particles depends on the thickness d of the optical functional layer 16, but is preferably 5 nm or more and 80 nm or less. It is more preferably 8 nm or more, and even more preferably 10 nm or more. It is more preferably 70 nm or less, and even more preferably 60 nm or less. When the average particle diameter of the silica particles is within these preferred ranges, excellent anti-reflection effect and transparency can be obtained in the optical functional layer 16. The average particle diameter is a volume-based average arithmetic value obtained by a laser diffraction / scattering method according to JIS Z8825. It includes not only the primary particle diameter but also the secondary particle diameter which is an aggregate of particles.

[0075] When the silica particles are hollow particles, the refractive index of the hollow silica particles is preferably in the range of 1.01 to 1.45, more preferably 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 in this range, excellent antireflection effect can be obtained.

[0076] The content of silica particles in the optical functional layer 16 is preferably 6.0% by mass or more and 50% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16. When the content of silica particles in the optical functional layer 16 is 6.0% by mass or more with respect to 100% by mass of the solid content of the optical functional layer 16, excellent scratch resistance can be obtained. From this viewpoint, the content of silica particles in the optical functional layer 16 is more preferably 10% by mass or more, further preferably 20% by mass or more, and particularly preferably 30% by mass or more with respect to 100% by mass of the solid content of the optical functional layer 16. And, when the content of silica particles in the optical functional layer 16 is 50% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16, the deterioration of scratch resistance due to the shortage of binder resin components is suppressed. From this viewpoint, the content of hollow silica particles in the optical functional layer 16 is more preferably 45% by mass or less, further preferably 40% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16.

[0077] The silica particles are preferably surface-treated with a silane coupling agent having a reactive group capable of forming a bond with a (meth)acrylate compound. The silane coupling agent has a reactive group capable of forming a bond with a (meth)acrylate compound, so that the silica particles surface-treated with the silane coupling agent can be firmly bonded to the (meth)acrylate contained in the optical functional layer 16, and further bonded to the reactive group contained in the adjacent layer such as the hard coat layer 14. When these bonds are formed, the scratch resistance of the anti-reflection film 10 is improved. As the silane coupling agent, the same one as that used for the surface treatment of the alumina particles can be suitably applied.

[0078] When the optical functional layer 16 contains silica particles in addition to alumina particles, the total amount of alumina particles and silica particles in the optical functional layer 16 is preferably 0.1% by mass or more and 50% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16. When the total amount of alumina particles and silica particles in the optical functional layer 16 is 0.1% by mass or more with respect to 100% by mass of the solid content of the optical functional layer 16, excellent scratch resistance can be obtained. From this viewpoint, the total amount of alumina particles and silica particles in the optical functional layer 16 is more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more with respect to 100% by mass of the solid content of the optical functional layer 16. On the other hand, when the total amount of alumina particles and silica particles in the optical functional layer 16 is 50% by mass or less with respect to 100% by mass of the solid content of the optical functional layer 16, the alumina particles and silica particles can be sufficiently held in the optical functional layer 16, and therefore excellent scratch resistance can be obtained. From this viewpoint, the total amount of alumina particles and silica particles in the optical functional layer 16 is more preferably 45% by mass or less, and further preferably 40% by mass or less, relative to 100% by mass of the solid content of the optical functional layer 16.

[0079] (6) Other ingredients The composition for forming the optical functional layer 16 may contain a silicone compound in addition to the addition reaction product of the amino-modified organopolysiloxane that may or may not form an addition reaction product with the polyfunctional (meth)acrylate compound having a reactive group. The silicone compound may or may not have a reactive group, but it is preferable that the silicone compound has a reactive group from the viewpoint of scratch resistance. And, it is preferable that the reactive group is capable of forming a bond with the polyfunctional (meth)acrylate compound contained in the composition. Examples of the silicone compound having a reactive group include polydimethylsiloxane having a (meth)acrylic group on a side chain or at one or both ends. Examples of such compounds include Shin-Etsu Chemical's "X-22-164", "X-22-164AS", "X-22-164A", "X-22-164B", "X-22-164C", "X-22-164E", "X-22-2445", "X-22-174ASX", "X-22-174BX", "KF-2012", "X-22-2426", and "X-22-2404", and Evonik's "TEGO Rad2100", "TEGO Rad2200N", "TEGO Rad2250", "TEGO Rad2300", "TEGO Rad2500", "TEGO Rad2700", and "TEGO Rad2800'', BYK Chemie's ``BYK-UV3500'', ``BYK-UV3505'', ``BYK-UV3510'', ``BYK-UV3511'', ``BYK-UV3518'', ``BYK-UV351'' 9” “BYK-UV3530” “BYK-UV3535” “BYK-UV3570” “BYK-UV3575” “BYK-UV3576” “BYK-UV3590” “BYK-UV3595” Examples include JNC's "Silaplane FM-0711," "Silaplane FM-0721," "Silaplane FM-0725," "Silaplane FM-7711," "Silaplane FM-7721," and "Silaplane FM-7725," Daicel-Allnex's "EBECRYL350," "EBECRYL1360," "EBECRYL1365," and "KRM8479," and MIWON's "Miramer SIU100" and "Miramer SIU2400."

[0080] When the (meth)acrylic compound has a reactive group reactive to ultraviolet light (when the composition is an ultraviolet curable resin), the composition for forming the optical functional layer 16 preferably contains a photopolymerization initiator. Furthermore, the composition for forming the optical functional layer 16 may contain a solvent as necessary.

[0081] The binder resin of the optical functional layer 16 may be composed only of an addition reaction product (and its unreacted components) of a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, or may contain other ultraviolet-curable resins such as (meth)acrylic resins, or may be composed of a combination of an ultraviolet-curable resin and a non-ultraviolet-curable resin. As the non-ultraviolet-curable resin, 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 optical functional layer 16.

[0082] The content of the photopolymerization initiator is preferably in the range of 0.1% by mass to 10% by mass, based on the total solid content of the composition for forming the optical functional layer 16. More preferably, it is in the range of 1% by mass to 5% by mass.

[0083] In addition, the optical functional layer 16 may contain additives, etc., as necessary. Examples of such additives include dispersants, leveling agents, defoamers, thixotropic agents, antibacterial agents, flame retardants, slip agents, refractive index adjusters, inorganic particles other than alumina particles and silica particles, and resin particles. When inorganic particles other than alumina particles and silica particles are contained, the inorganic particles may also be surface-treated with a silane coupling agent having a reactive group capable of forming a bond with a (meth)acrylate compound, similar to the alumina particles and silica particles. However, it is preferable that the optical functional layer 16 does not contain a fluorine-containing compound having a fluoroalkyl group. Even if a fluorine-containing compound having a fluoroalkyl group is contained, the content is preferably suppressed to 1 mass% or less based on the total solid content of the composition for forming the optical functional layer 16.

[0084] (7) Characteristics of the optical functional layer In this embodiment, since the optical functional layer 16 has the above-mentioned component composition, the water contact angle of the surface of the antireflection film 10, i.e., the surface of the optical functional layer 16, is likely to be large, at 90° or more. This indicates that the antireflection film 10 has high antifouling properties. In addition, the large water contact angle improves the slipperiness of the surface of the optical functional layer 16, which contributes to improving the scratch resistance. From the viewpoint of obtaining higher antifouling properties, the water contact angle of the surface of the optical functional layer 16 is preferably 93° or more, more preferably 95° or more. There is no particular upper limit to the water contact angle of the surface of the optical functional layer 16, but it is generally 130° or less.

[0085] In this embodiment, since the optical functional layer 16 functions as a low refractive index layer, the refractive index of the optical functional layer 16 is preferably lower than that of the hard coat layer 14, and is preferably 1.35 or more and 1.53 or less. If the refractive index is 1.35 or more, the strength of the optical functional layer 16 can be made sufficient, and good scratch resistance can be obtained. On the other hand, if the refractive index is 1.53 or less, the antireflection film 10 can have a lower reflectance. From the above viewpoint, the refractive index of the optical functional 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.

[0086] The average thickness d of the optical functional layer 16 is preferably in the range of 60 nm to 110 nm. More preferably, it is 65 nm or more, and even more preferably, it is 70 nm or more. Also, it is more preferably 105 nm or less, and even more preferably, it is 100 nm or less. Within this range, a good low luminous reflectance can be obtained, and light reflection can be reduced. The thickness of the optical functional layer 16 is the thickness of a relatively smooth portion in the portion without unevenness caused by alumina particles in the thickness direction.

[0087] (Anti-reflection film manufacturing method) To manufacture the anti-reflection film 10, the hard coat layer 14 and the optical functional layer 16 may be formed in this order on the surface of the base film 12. To form each layer, a composition for forming each layer may be applied, dried as necessary, and then cured by a method according to the curing property of the composition, such as irradiation with ionizing radiation including ultraviolet light. After forming a layer, a composition for forming the next layer may be applied, dried as necessary, and then cured. By sequentially repeating this process, a laminated structure of the hard coat layer 14 and the optical functional layer 16 may be formed, and the anti-reflection film 10 may be manufactured.

[0088] A wet method can be suitably used for coating the composition forming each layer. Specifically, for example, 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, kiss coating, etc., and various printing methods such as inkjet printing, offset printing, screen printing, flexographic printing, etc. can be used.

[0089] The drying step for each layer is not particularly limited as long as it can remove the solvent used in the coating liquid, but is preferably performed at a temperature of 50 to 150° C. for about 10 to 180 seconds.

[0090] For the irradiation of each layer with ultraviolet light, a high-pressure mercury lamp, an electrodeless (microwave type) lamp, a xenon lamp, a metal halide lamp, or any other ultraviolet light irradiation device can be used. The ultraviolet light irradiation may be performed in an inert gas atmosphere such as nitrogen, if necessary. The amount of ultraviolet light irradiation is not particularly limited, but is preferably 50 to 800 mJ / cm. 2 is preferable, and 100 to 300 mJ / cm 2 is more preferred.

[0091] When forming the 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 the surface treatment include corona treatment, plasma treatment, hot air treatment, ozone treatment, and ultraviolet treatment.

[0092] (Anti-reflective film characteristics) The anti-reflection film 10 having the above-mentioned configuration has a base film 12, a hard coat layer 14 formed on the surface of the base film 12, and an optical functional layer 16 formed on the surface of the hard coat layer 14. The optical functional layer 16 contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, and at least a portion of the polyfunctional (meth)acrylate compound and at least a portion of the amino-modified organopolysiloxane form an addition reaction product. The optical functional layer 16 is further composed of a cured product of an ionizing radiation-curable composition containing alumina particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound, and thus has high anti-reflection properties, anti-fouling properties, and excellent scratch resistance.

[0093] The anti-reflection film 10 has high antifouling properties, such as a water contact angle of 90° or more, so that stains such as fingerprints are less likely to adhere to the surface of the anti-reflection film 10, and even if they do adhere, they can be easily removed. Furthermore, in the anti-reflection film 10 according to this embodiment, the polyfunctional (meth)acrylate compound having a reactive group contained in the optical functional layer 16 and the amino-modified organopolysiloxane form an addition reaction product, which enhances the scratch resistance of the anti-reflection film 10. In addition, the optical functional layer 16 contains alumina particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound, which further enhances the effect of improving scratch resistance. Thus, the anti-reflection film 10 according to this embodiment has high anti-reflection properties and antifouling properties as well as high scratch resistance, and is therefore particularly suitable for applications that are frequently touched by fingers, such as those placed on the surface of a touch panel.

[0094] In addition, the anti-reflection film 10 does not need to contain, and preferably does not contain, a fluorine-containing compound having a fluoroalkyl group in the optical functional layer 16. A fluorine-containing compound having a fluoroalkyl group is generally used in an anti-reflection film to adjust the optical functional layer to a low refractive index or to impart slipperiness and anti-soiling properties, but in the present invention, the optical functional layer 16 contains an amino-modified organopolysiloxane that forms an addition reaction product with a multifunctional (meth)acrylate compound, at least a part of which has a reactive group, so that sufficient anti-soiling properties can be obtained without using a fluorine-containing compound having a fluoroalkyl group. By not containing a fluorine-containing compound having a fluoroalkyl group, the anti-reflection film 10 is less likely to have a negative impact on the environment.

[0095] From the viewpoint of good visibility, the haze of the antireflection film 10 is preferably 2.5 or less, more preferably 2.0 or less, and even more preferably 1.5 or less. The luminous reflectance of the antireflection 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 2.5% or less, the antireflection film 10 can be considered to have sufficiently high antireflection properties.

[0096] <Other types of anti-reflective film> As described above, the anti-reflection film according to the present invention is a film in which the hard coat layer 14 and the optical functional layer 16 are laminated in this order on the surface of the base film 12. As long as the optical functional layer 16 has a predetermined composition, the anti-reflection film is not limited to the configuration of the anti-reflection film 10 according to the first embodiment. In addition to the base film 12, the hard coat layer 14, and the optical functional layer 16, other types of layers may be formed between the base film 12 and the hard coat layer 14, between the hard coat layer 14 and the optical functional layer 16, or on the surface of the optical functional layer 16. The optical functional layer 16 may be composed of a plurality of layers having different compositions. Other embodiments of the anti-reflection film according to the present invention will be exemplified below.

[0097] Second Embodiment 2 shows an antireflection film 20 according to the second embodiment. The antireflection film 20 according to the second embodiment has a base film 12 and a hard coat layer 14 formed on the surface of the base film 12, and further has a high refractive index layer 15 and a low refractive index layer 16, in this order, on the surface of the hard coat layer 14. The low refractive index layer 16 has a similar structure to the optical functional layer 16 constituting the antireflection film 10 according to the first embodiment.

[0098] The antireflection film 20 according to the second embodiment differs from the antireflection film 10 according to the first embodiment in that a high refractive index layer 15 is provided between the hard coat layer 14 and the low refractive index layer (optical functional layer) 16. Other than this, it is similar to the antireflection film 10 according to the first embodiment, and therefore a description of the similar configuration will be omitted.

[0099] 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. Preferably, the refractive index of the low refractive index layer 16 is 1.35 or more and 1.53 or less, and the high refractive index layer 15 has a higher refractive index. The refractive index of the high refractive index layer 15 is preferably in the range of 1.55 or more and 1.90 or less, and more preferably 1.60 or more and 1.80 or less. By providing the high refractive index layer 14, the antireflection effect of the antireflection film 20 can be improved.

[0100] The material of the high refractive index layer 15 is not particularly limited, and may be any known material conventionally used in anti-reflection films, etc., so as to obtain a desired refractive index. For example, the material may be appropriately selected from the materials described above as usable materials for the hard coat layer 14 and the low refractive index layer (optical functional layer) 16. The refractive index of the high refractive index layer 15 can be adjusted by the selection and blending amount of the binder resin, inorganic oxide particles, and resin particles. For example, by adding a sufficient amount of inorganic oxide particles, it is possible to form a high refractive index layer 15 having a higher refractive index than the low refractive index layer 16.

[0101] The high refractive index layer 15 does not need to have the composition and characteristics of the optical functional layer described in the first embodiment, but may be configured as the optical functional layer described in the first embodiment. That is, like the low refractive index layer 16, the high refractive index layer 15 may be configured as a layer of a cured product of an ionizing radiation curable composition, which contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, and at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and further contains alumina particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound. In this case, the optical functional layer is configured of two or more thin layers having different refractive indices, including the high refractive index layer 15 and the low refractive index layer 16. The refractive indices of the high refractive index layer 15 and the low refractive index layer 16 may be made different from each other by selecting the binder resin, inorganic oxide particles, and resin particles to be specifically used, the amount of each of them to be mixed, and the like. Furthermore, even if the high refractive index layer 15 does not contain alumina particles that have been surface-treated with a silane coupling agent having a predetermined reactive group, the high refractive index layer 15 may be configured as a layer of a cured product of an ionizing radiation-curable composition that contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, in which at least a portion of the polyfunctional (meth)acrylate compound and at least a portion of the amino-modified organopolysiloxane form an addition reaction product.

[0102] The average thickness of the high refractive index layer 15 varies depending on the refractive index setting, but by setting it to, for example, 50 nm or more and 200 nm or less, the antireflection function can be further improved. The high refractive index layer 15 may be provided by laminating two or more layers having mutually different refractive indices.

[0103] Third embodiment 3 shows an anti-reflection film 30 according to a third embodiment. The anti-reflection film 30 according to the third embodiment has a base film 12, a hard coat layer 14 formed on one surface of the base film 12, and an optically functional layer 16 formed on the surface of the hard coat layer 14. The base film 12 also has a transparent adhesive layer 22 on the other surface. A release film 24 is disposed on the surface of the transparent adhesive layer 22 as necessary. The release film 24 functions as a protective layer for the transparent adhesive layer 22 before use of the anti-reflection film 30, and is peeled off from the transparent adhesive layer 22 when the anti-reflection film 30 is used.

[0104] The anti-reflection film 30 of the third embodiment differs from the anti-reflection film 20 of the first embodiment in that it has a transparent adhesive layer 22 on the other side of the base film 12, but is otherwise similar to the anti-reflection film 10 of the first embodiment, and therefore a description of the similar configuration will be omitted.

[0105] The transparent adhesive layer 22 is for attaching the anti-reflection film 30 to the surface of a display or the like with good adhesion. Furthermore, the anti-reflection film 30 has the effect of preventing glass of a display or the like from shattering by having the transparent adhesive layer 22. That is, the anti-reflection film 30 also functions as a shatterproof film.

[0106] The adhesive composition forming the transparent adhesive layer 22 may contain a known adhesive resin such as an acrylic adhesive, a silicone adhesive, or a urethane adhesive. Among them, an acrylic adhesive is preferred from the viewpoint of optical transparency and heat resistance. The adhesive composition preferably contains a crosslinking agent to increase the cohesive force of the transparent adhesive layer 22. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, and a chelate crosslinking agent.

[0107] The pressure-sensitive adhesive composition may contain additives as necessary. Examples of additives include known additives such as plasticizers, silane coupling agents, surfactants, antioxidants, fillers, curing accelerators, and curing retarders. In addition, from the viewpoint of productivity, the pressure-sensitive adhesive composition may be diluted with an organic solvent.

[0108] The thickness of the transparent adhesive layer 22 is not particularly limited, but is preferably within the range of 5 μm to 100 μm, more preferably 10 μm or more and 50 μm or less.

[0109] The transparent adhesive layer 22 can be formed by a method of directly applying an adhesive composition onto the other side of the base film 12, a method of applying an adhesive composition onto the side of a release film 24 and then transferring it onto the other side of the base film 12, or a method of applying an adhesive composition onto the side of a first release film and then laminating a second release film, peeling off one of the release films, and transferring it onto the other side of the base film 12.

[0110] From the viewpoint of the effect of preventing glass from scattering, the transparent adhesive layer 22 preferably has an adhesive strength to glass of 4 N / 25 mm or more, more preferably 6 N / 25 mm or more, and further preferably 10 N / 25 mm or more.

[0111] (Fourth embodiment) 4 shows an anti-reflection film 40 according to a fourth embodiment. The anti-reflection film 40 according to the fourth embodiment has a base film 12, a hard coat layer 14 formed on one surface of the base film 12, an optical functional layer 16 formed on the surface of the hard coat layer 14, and a protective film 28 arranged on the surface of the optical functional layer 16 via an adhesive layer 26. In addition, a transparent adhesive layer 22 is formed on the other surface of the base film 12. A release film 24 is arranged on the surface of the transparent adhesive layer 22 as necessary.

[0112] The anti-reflection film 40 of the fourth embodiment differs from the anti-reflection film 30 of the third embodiment in that it has a protective film 28 on the surface of the optical functional layer 16 via an adhesive layer 26, but is otherwise similar to the anti-reflection film 30 of the third embodiment, and therefore a description of the similar configuration will be omitted.

[0113] The protective film 28 can prevent the surface of the optical functional layer 16 from being scratched when the anti-reflection film 40 is handled, for example, by continuous processing in a roll process or by bonding to a display or the like. The protective film 28 is attached to the surface of the optical functional layer 16 via the adhesive layer 26. The protective film 28 is peeled off from the surface of the optical functional layer 16 together with the adhesive layer 26 after processing of the anti-reflection film 40. For this reason, the adhesive layer 26 is adjusted so that the adhesive force between the protective film 28 and the adhesive layer 26 is stronger than the adhesive force between the optical functional layer 16 and the adhesive layer 26, and the adhesive force between the optical functional layer 16 and the adhesive layer 26 can be peeled off at the interface. In the anti-reflection film 50 according to this embodiment, various surface characteristics such as the water contact angle of the surface are specified for the surface in a state in which the protective film 28 and the adhesive layer 26 are peeled off.

[0114] The material constituting the protective film 28 can be appropriately selected from those exemplified as the material 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 or more and 500 μm or less, or in the range of 2 μm or more and 200 μm or less.

[0115] As the adhesive layer 26, those described in International Publication No. 2021 / 020504 filed by the applicant can be suitably applied. The adhesive forming the adhesive layer 26 is not particularly limited, and an acrylic adhesive, a silicone adhesive, a urethane adhesive, or the like can be suitably used. In particular, an acrylic adhesive is suitable because it has excellent transparency and heat resistance. The acrylic adhesive is preferably formed from an adhesive composition containing a (meth)acrylic polymer and a crosslinking agent.

[0116] The (meth)acrylic polymer is a homopolymer or copolymer of a (meth)acrylic monomer. Examples of the (meth)acrylic monomer include an alkyl group-containing (meth)acrylic monomer, a carboxyl group-containing (meth)acrylic monomer, and a hydroxyl group-containing (meth)acrylic monomer.

[0117] Examples of the crosslinking agent include an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a metal chelate-based crosslinking agent, a metal alkoxide-based crosslinking agent, a carbodiimide-based crosslinking agent, an oxazoline-based crosslinking agent, an aziridine-based crosslinking agent, a melamine-based crosslinking agent, etc. The crosslinking agent may be used alone or in combination of two or more.

[0118] The adhesive composition may contain other additives in addition to the (meth)acrylic polymer and the crosslinking agent. Examples of other additives include crosslinking accelerators, crosslinking retarders, tackifiers, antistatic agents, silane coupling agents, plasticizers, peeling aids, pigments, dyes, wetting agents, thickeners, UV absorbers, preservatives, antioxidants, metal deactivators, alkylating agents, and flame retardants. These are appropriately selected and used depending on the application and purpose of the adhesive.

[0119] The thickness of the adhesive layer 26 is not particularly limited, but is preferably within the range of 1 μm to 10 μm, more preferably 2 μm or more and 7 μm or less.

[0120] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0121] For example, in the above embodiment, it is described that the surface of the base film 12 may be subjected to a surface treatment, but instead of the surface treatment, an easy-adhesion layer may be provided on the surface of the base film 12. In addition, various functional layers such as a gas barrier improving layer, an antistatic layer, and an oligomer block layer may be provided in advance on the surface of the base film 12 before each layer is formed. As the antistatic layer, those described in International Publication No. 2021 / 020504 filed by the applicant of the present application can be suitably applied.

[0122] As shown in Fig. 3, the transparent adhesive layer 22 and the release film 24 in the third embodiment are shown as being added to the anti-reflection film 10 of the first embodiment shown in Fig. 1, but they may also be added to the anti-reflection film 20 of the second embodiment shown in Fig. 2. Also, as shown in Fig. 4, the adhesive layer 26 and the protective film 28 in the fourth embodiment are shown as being added to the anti-reflection film 30 of the third embodiment shown in Fig. 3, but they may also be added to the anti-reflection film 10 of the first embodiment shown in Fig. 1, or to the anti-reflection film 20 of the second embodiment shown in Fig. 2.

[0123] In any embodiment, it is preferable that not only the optical functional layer 16 but also each layer formed on the surface of the base film 12 does not contain a fluorine-containing compound having a fluoroalkyl group, so that the antireflection film is less likely to adversely affect the environment. EXAMPLES

[0124] The present invention will be described in detail below with reference to examples and comparative examples. Unless otherwise specified, the preparation and evaluation of samples were carried out at room temperature in the atmosphere.

[0125] (Examples 1 to 9) <Preparation of hard coat layer forming composition> A photopolymerization initiator "Omnirad127" (manufactured by IGM Resins BV) was added to an ultraviolet-curable resin composition ESS-620 (manufactured by DIC; urethane acrylate resin, solvent (ethyl acetate); solid content concentration 79% by mass) so as to be 3% by mass relative to the total amount of the composition for forming a hard coat layer. Further, ethyl acetate was added so as to be 31% by mass of solid content, thereby preparing a composition for forming a hard coat layer.

[0126] <Preparation of Composition for Forming High Refractive Index Layer> A composition for forming a high refractive index layer was prepared by adding methyl ethyl ketone to an ultraviolet-curable resin composition TYZ65-01 (manufactured by Toyochem; acrylic resin, zirconium oxide (average particle size 80 nm), photopolymerization initiator (the above-mentioned "Omnirad127"), solvent (cyclohexanone, methyl isobutyl ketone, propylene glycol monomethyl ether); solids concentration 35% by mass) so that the solids concentration was 8% by mass.

[0127] <Preparation of reactive resin composition containing addition reaction product> A reactive resin composition was prepared that contained a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, and that formed an addition reaction product thereof. Specifically, the polyfunctional (meth)acrylate compound having a reactive group and the amino-modified organopolysiloxane were weighed out so as to obtain the blending composition (mass ratio of solid content) shown in Table 1, and a solvent (toluene / isopropyl alcohol) was added so that the solid content concentration became 30 mass%. The mixture was heated to 50°C and stirred for 1 hour to cause a Michael addition reaction, thereby obtaining a reactive resin composition containing an addition reaction product of the polyfunctional (meth)acrylate compound and the amino-modified organopolysiloxane. The polyfunctional acrylate compound used was ARONIX M-403 (manufactured by Toagosei, a mixture of dipentaerythritol penta- and hexaacrylates, acrylic equivalent 100 eq, solids concentration 100% by mass). The amino-modified organopolysiloxane used was DOWSIL BY16-853U (manufactured by Dow Toray, aminopropyl-terminated polydimethylsiloxane, amino equivalent 450 eq, solids concentration 100% by mass).

[0128] <Preparation of alumina particles surface-treated with a silane coupling agent having a reactive group> 25g of untreated alumina particles (average particle size 160nm), 2.5g of silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-5103", 3-acryloxypropyltrimethoxysilane), and 72.5g of propylene glycol monomethyl ether were added, and mixed and dispersed at 4000rpm for 30 minutes using a homomixer (Primix Corporation "Homomixer MARKII 2.5 type") to obtain a dispersion of alumina particles surface-treated with a silane coupling agent having an acryloyl group as a reactive group. The alumina particles surface-treated with a silane coupling agent having a reactive group prepared here may be simply referred to as alumina particles below.

[0129] <Preparation of composition for forming low refractive index layer> A composition for forming a low refractive index layer was prepared by blending the reactive resin composition containing the addition reaction product prepared above, the alumina particles and silica particles (only Examples 1 to 3 and Examples 8 to 9) prepared above, and a photopolymerization initiator to obtain the blending composition (mass % of the total solid content) shown in Table 1, and adjusting the solid content concentration to 3.5 mass % using a solvent (MEK / cyclohexanone = 7 / 3). Hereinafter, the composition for forming a low refractive index layer prepared in Example 1 may be referred to as composition 1 for forming an optical functional layer.

[0130] The materials used for the composition for forming the low refractive index layer are as follows. Solid silica particles: Nissan Chemical's "MEK-AC-2140Z"; solid silica particles (average particle size: 12 nm) surface-treated with a silane coupling agent having a methacryloyl group as a reactive group, solvent (MEK); solid content concentration 40% by mass Hollow silica particles 1: "Surulia 4320" manufactured by JGC Catalysts and Chemicals Co., Ltd., hollow silica particles surface-treated with a silane coupling agent having a methacryloyl group as a reactive group, average particle diameter 60 nm, solid content concentration 20% by mass Hollow silica particles 2: "Surulia 2320" manufactured by JGC Catalysts and Chemicals Co., Ltd., hollow silica particles surface-treated with a silane coupling agent having a methacryloyl group as a reactive group, average particle diameter 50 nm, solid content concentration 20% by mass Photopolymerization initiator: "Omnirad127"

[0131] <Preparation of hard coat layer> For each of Examples 1 to 9, the composition for forming a hard coat layer was applied to a substrate film (Toray's "Lumirror #50-U403", a polyethylene terephthalate film, thickness 50 μm) using a #12 wire bar, dried at 80°C for 60 seconds, and then irradiated with a high-pressure mercury lamp with a light intensity of 200 mJ / cm. 2 The coated film was irradiated with ultraviolet light to form a hard coat layer (film thickness: 4 μm).

[0132] <Preparation of high refractive index layer> For each of Examples 1 to 9, a composition for forming a high refractive index layer was applied onto the surface of the hard coat layer, dried at 80°C for 60 seconds, and then irradiated with a light intensity of 200 mJ / cm using a high pressure mercury lamp in a nitrogen atmosphere. 2 The film was irradiated with ultraviolet light of 100 nm to form a high refractive index layer (thickness: 110 nm).

[0133] <Preparation of low refractive index layer> For each of Examples 1 to 9, the composition for forming a low refractive index layer was applied onto the surface of the high refractive index layer using a #3 wire bar, dried at 100°C for 60 seconds, and then irradiated with a high-pressure mercury lamp at a light intensity of 200 mJ / cm under a nitrogen atmosphere. 2 The antireflection films of Examples 1 to 9 were prepared by irradiating the film with ultraviolet light of 1000 nm to form a low refractive index layer (optical functional layer).

[0134] Comparative Example 1 A polyfunctional acrylate compound (the above "Aronix M-403"), an amino-modified organopolysiloxane (the above DOWSIL BY16-853U), silica particles (the above "MEK-AC-2140Z"), alumina particles (alumina particles surface-treated with a silane coupling agent having an acryloyl group as the reactive group), and a photopolymerization initiator (the above "Omnirad127") were mixed to obtain the composition (mass % of the total solid content) shown in Table 2, and the solid content concentration was adjusted to 3.5 mass % using a solvent (MEK / cyclohexanone = 7 / 3), to prepare an optical functional layer forming composition 2. At this time, a Michael addition reaction product of the polyfunctional acrylate compound and the amino-modified organopolysiloxane was not formed, and the polyfunctional acrylate compound and the amino-modified organopolysiloxane were mixed as they were. An antireflection film of Comparative Example 1 was produced in the same manner as in Example 1, except that the composition 1 for forming an optical functional layer was changed to the composition 2 for forming an optical functional layer.

[0135] Comparative Example 2 A polyfunctional acrylate compound (the above-mentioned "Aronix M-403"), a silicone-modified acrylate "TEGO Rad2800" (manufactured by Evonik, reactive silicone having an acryloyloxy group on the side chain of the silicone skeleton, solid content: 100 mass%), alumina particles (alumina particles surface-treated with a silane coupling agent having an acryloyl group as the reactive group) and a photopolymerization initiator (the above-mentioned "Omnirad127") were mixed to obtain the composition shown in Table 2 (mass % of the total solid content), and the solid content was adjusted to 3.5 mass % using a solvent (MEK / cyclohexanone = 7 / 3), thereby preparing a composition 3 for forming an optical functional layer. An antireflection film of Comparative Example 2 was produced in the same manner as in Example 1, except that the composition 1 for forming an optical functional layer was changed to the composition 3 for forming an optical functional layer.

[0136] Comparative Example 3 An amino-modified organopolysiloxane (DOWSIL BY16-853U described above), a silicone-modified acrylate (TEGO Rad2800 described above), alumina particles (alumina particles surface-treated with a silane coupling agent having an acryloyl group as the reactive group described above), and a photopolymerization initiator (Omnirad127 described above) were mixed to obtain the composition shown in Table 2 (mass % of the total solid content), and the solid content was adjusted to 3.5 mass % using a solvent (MEK / cyclohexanone = 7 / 3), thereby preparing a composition 4 for forming an optical functional layer. An antireflection film of Comparative Example 3 was produced in the same manner as in Example 1, except that the composition 1 for forming an optical functional layer was changed to the composition 4 for forming an optical functional layer.

[0137] Comparative Example 4 A Michael addition reaction product of a multifunctional acrylate compound and an amino-modified organopolysiloxane, a reactive resin composition containing the addition reaction product, and a photopolymerization initiator (the above-mentioned "Omnirad127") were mixed to obtain the composition shown in Table 2 (mass % of the total solid content), and the solid content concentration was adjusted to 3.5 mass % using a solvent (MEK / cyclohexanone = 7 / 3), to prepare a composition for forming an optical functional layer 5. Here, the multifunctional acrylate compound and the amino-modified organopolysiloxane were used in the preparation of the composition after forming a Michael addition reaction product in the same manner as in Examples 1 to 9 described above, using the mass ratios shown in Table 2. The materials used were also the same as those in Examples 1 to 9. An antireflection film of Comparative Example 4 was produced in the same manner as in Example 1, except that the composition 1 for forming an optical functional layer was changed to the composition 5 for forming an optical functional layer.

[0138] <Evaluation method> (Thickness and refractive index of each layer) The thickness and refractive index of each of the hard coat layer, high refractive index layer, and low refractive index layer were evaluated for each sample. At this time, each time each layer was formed, the reflection spectrum in the wavelength range of 380 to 780 nm obtained using a microspectrophotometer (Otsuka Electronics' "OPTM-F1") and the theoretical spectrum derived based on the Fresnel equation were curve-fitted by the least squares method to calculate the thickness and refractive index of each layer at a wavelength of 550 nm.

[0139] (Luminous reflectance) The back surface of the anti-reflection film (the surface opposite to the low refractive index layer) was roughened with #400 sandpaper and painted with black paint, and the 5° regular reflectance of the surface of the anti-reflection film at wavelengths of 380 nm to 780 nm was measured using an ultraviolet-visible-near infrared spectrophotometer (Shimadzu Corporation's "UV-3600"), and the luminous reflectance was calculated by multiplying this measurement value by the relative luminous efficiency value. If the luminous reflectance is 2.0% or less, the anti-reflection properties can be considered sufficient.

[0140] (water contact angle) The water contact angle was measured on the surface of the anti-reflection film produced. A contact angle meter (DropMaster DMo-502, manufactured by Kyowa Interface Science) was used for the measurement, and 4 μL of pure water was dropped onto the surface of the sample (surface of the low refractive index layer) to measure the water contact angle. If the water contact angle is 90° or more, it can be considered to be sufficiently large from the viewpoint of antifouling properties.

[0141] (Hayes) The haze of the entire anti-reflection film was measured using the Nippon Denshoku Industries Co., Ltd. "Haze Meter NDH8000" according to the method of JIS-K7136. If the haze is 2.0% or less, the anti-reflection film can be said to have transparency.

[0142] (Scratch resistance) A steel wool resistance test was carried out for each sample. In this case, a flat surface abrasion tester (Daiei Scientific Instruments Manufacturing Co., Ltd. "DAS-400") was used, and steel wool #0000 (manufactured by Nippon Steel Wool Co., Ltd.) fixed to a flat surface friction element of 20 mm x 20 mm was placed on the surface of the anti-reflective film of each sample and reciprocated. The stroke length of the test table was 50 mm, the test table reciprocation speed was 60 reciprocations / min, and the applied load was 1 kg. The sample was visually observed every 100 reciprocations up to 500 reciprocations, and every 500 reciprocations after 500 reciprocations after that, and the maximum number of reciprocations until a scratch of 10 mm or more in length was observed was used as the evaluation value. If the evaluation value is 500 times or more, it can be considered that the sample has sufficient abrasion resistance. Furthermore, if the evaluation value is 1000 times or more, it can be considered that the sample has high abrasion resistance, and if the evaluation value is 1500 times or more, it can be considered that the sample has particularly high abrasion resistance.

[0143] <Evaluation Results> Table 1 shows the evaluation results for Examples 1 to 9, and Table 2 shows the evaluation results for Comparative Examples 1 to 4, along with the component composition of the low refractive index layer (optical functional layer) (unit: mass % of the total solid content of each layer) and the layer structure of the antireflection film.

[0144] [Table 1]

[0145] [Table 2]

[0146] As shown in Table 1, in all of Examples 1 to 9, the low refractive index layer (optical functional layer) contains a Michael addition reaction product of a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, and alumina particles surface-treated with a silane coupling agent having an acryloyl group, and has high scratch resistance evaluated as 500 times or more. In addition, the water contact angle of the anti-reflective film surface is 90° or more, indicating that the anti-reflective film has high antifouling properties.

[0147] On the other hand, in Comparative Example 1, the evaluation value of scratch resistance is significantly below 500 times, which corresponds to the fact that an addition reaction product between a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane is not formed, and scratch resistance is insufficient. From this, it can be said that even if an amino-modified organopolysiloxane is contained in the low refractive index layer (optical functional layer), it does not show a sufficient effect in improving scratch resistance unless an addition reaction product is formed with the polyfunctional (meth)acrylate compound.

[0148] The scratch resistance is also insufficient in Comparative Example 2, in which a silicone-modified acrylate is used instead of an amino-modified organopolysiloxane. In Comparative Example 3, in which a silicone-modified acrylate is used instead of a polyfunctional (meth)acrylate compound, the curing property is poor, the low refractive index layer is not sufficiently cured, and the scratch resistance is also low. From these facts, it is understood that even if a silicone-modified acrylate is added to the low refractive index layer (optical functional layer), it is not possible to obtain a high scratch resistance improvement effect like that obtained when an addition reaction product of a polyfunctional (meth)acrylate compound and an amino-modified organopolysiloxane is used.

[0149] In Comparative Example 4, the low refractive index layer does not contain alumina particles, and the component composition of the low refractive index layer differs only in the presence or absence of alumina particles between Example 7 and Comparative Example 4. Unlike Example 7, Comparative Example 4 has an evaluation value of scratch resistance that is significantly below 500 times, and scratch resistance is insufficient. From this, it can be seen that even if the low refractive index layer (optical functional layer) contains an addition reaction product of a polyfunctional (meth)acrylate compound and an amino-modified organopolysiloxane, the effect of improving scratch resistance cannot be sufficiently obtained unless alumina particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound are further contained.

[0150] As described above, the anti-reflection film has a base film, a hard coat layer formed on the surface of the base film, and an optical functional layer formed on the surface of the hard coat layer, the optical functional layer contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and further, the anti-reflection film is composed of a cured product of an ionizing radiation curable composition containing alumina particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound, so that the anti-reflection film has excellent antifouling properties and scratch resistance.In addition, the anti-reflection film does not contain a fluorine-containing compound having a fluoroalkyl group, so that it is less likely to have a negative impact on the environment.

[0151] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0152] 10,20,30,40 Anti-reflective film 12 Base film 14 Hard coat layer 15 High refractive index layer 16 Optical functional layer (low refractive index layer) 22 Transparent adhesive layer 24 Release film 26 Adhesive layer 28 Protective Film

Claims

1. The optical film has a base film, a hard coat layer formed on a surface of the base film, and an optical functional layer formed on the surface of the hard coat layer, The optical functional layer is The composition contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, and at least a portion of the polyfunctional (meth)acrylate compound and at least a portion of the amino-modified organopolysiloxane form an addition reaction product, The present invention also provides an anti-reflective film formed from a cured product of an ionizing radiation curable composition, which contains alumina particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound.

2. The anti-reflection film according to claim 1 , wherein the optical functional layer does not contain a fluorine-containing compound having a fluoroalkyl group.

3. The antireflection film includes a high refractive index layer and a low refractive index layer in this order on a surface of the hard coat layer, the low refractive index layer is composed of the optical functional layer, 3. The anti-reflection film according to claim 1, wherein the high refractive index layer has a refractive index at a wavelength of 550 nm that is higher than the refractive index of the hard coat layer and is also higher than the refractive index of the low refractive index layer.

4. 3. The anti-reflection film according to claim 1, wherein the low refractive index layer contains silica particles that have been surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound.

5. In producing an anti-reflection film having a substrate film, a hard coat layer formed on a surface of the substrate film, and an optically functional layer formed on the surface of the hard coat layer, The optical functional layer contains a polyfunctional (meth)acrylate compound having a reactive group and an amino-modified organopolysiloxane, at least a part of the polyfunctional (meth)acrylate compound and at least a part of the amino-modified organopolysiloxane form an addition reaction product, and the optical functional layer is formed by applying an ionizing radiation curable composition containing alumina particles surface-treated with a silane coupling agent having a reactive group capable of forming a bond with the polyfunctional (meth)acrylate compound onto a surface of a hard coat layer and curing the composition by exposure to ionizing radiation.

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