Optical laminate and image display device using same

Abstract

Provided are an optical laminate and an image display device using the same, which have excellent glare resistance and fingerprint wipeability. The optical laminate has an uneven shape on the outermost surface and satisfies condition (1): 800 ≤ A ≤ 5,500 and condition (2): 0 < B ≤ 100. Here, A and B are values calculated from a second image obtained by performing fast Fourier transform on a first image obtained from three-dimensional data of an uneven height obtained by measuring an uneven shape by means of an optical interference method or a contact method. A is an average value of power spectrum intensity in a range of 50 cycle / mm ≤ f ≤ 100 cycle / mm, and B is an average value of power spectrum intensity in a range of 200 cycle / mm ≤ f ≤ 250 cycle / mm.

Description

Optical laminate and image display device using the same

[0001] The present invention relates to an optical laminate and an image display device using the same.

[0002] Anti-glare (AG) films are made by laminating an anti-glare layer made of a resin layer containing a filler on a transparent substrate, and prevent reflections of external light by diffusing reflected light with the unevenness of the anti-glare layer surface. Anti-glare low-reflection (AGLR) films are also known, which have a low refractive index layer (low-reflection (LR) layer) laminated on the anti-glare layer of an AG film and further suppress reflected light by utilizing optical interference. AG films and AGLR films (hereinafter collectively referred to as "anti-glare films") are used in a variety of displays.

[0003] In anti-glare films, when light emitted from inside the display panel of a display passes through the textured surface of the anti-glare layer, the surface texture acts like a lens, easily causing "glare" that disrupts the displayed image. It is known that glare can be reduced by increasing the difference between the refractive index of the resin and the refractive index of the filler particles to cause internal scattering, but this can easily cause the problem of whitening of the appearance. With the recent trend toward higher resolution display panels, suppressing this glare has become a challenge for anti-glare panels (see, for example, Patent Documents 1 and 2).

[0004] Patent No. 7192777 International Publication No. 2019 / 026471

[0005] Anti-glare films for anti-reflection touch panel displays are required to have not only anti-glare optical properties but also good wipeability of fingerprints that adhere to the surface during operation. To achieve this, anti-fouling ingredients such as fluorine compounds or silicone compounds are typically added to the outermost layer, but there is a limit to how much improvement can be made in the wipeability of fingerprints by adding only these ingredients.

[0006] Therefore, an object of the present invention is to provide an optical laminate that is excellent in anti-glare properties and fingerprint wiping properties, and an image display device using the same.

[0007] An optical laminate having an uneven shape on its outermost surface, characterized in that it satisfies the following conditions (1) and (2): 800≦A≦5,500 (1) 0<B≦100 (2) wherein three-dimensional data of unevenness height obtained by measuring the uneven shape using an optical interference method or a contact method is converted into first image data in which the unevenness height is a pixel value, the first image data is converted into a second image by fast Fourier transform, and the spatial frequency f of the X coordinate of the power spectrum of an image of the second image passing through the origin and within a range of ±20 pixels on the positive X axis is calculated, where A is the average value of the power spectrum intensity in the range of 50 cycles / mm≦f≦100 cycles / mm, and B is the average value of the power spectrum intensity in the range of 200 cycles / mm≦f≦250 cycles / mm.

[0008] According to the present invention, it is possible to provide an optical laminate having excellent anti-glare properties and fingerprint wiping properties, and an image display device using the same.

[0009] Fig. 1 is a cross-sectional view schematically showing one example of an optical laminate according to an embodiment. Fig. 2 is a cross-sectional view schematically showing another example of an optical laminate according to an embodiment. Fig. 3 is a diagram showing a method for evaluating antiglare properties. Fig. 4 is a diagram showing an example of evaluation of antiglare properties.

[0010] FIG. 1 is a cross-sectional view schematically illustrating an example of an optical laminate according to an embodiment.

[0011] The optical laminate 11 includes a transparent substrate 2 and an antiglare layer (first functional layer) 3 laminated on one surface of the transparent substrate 2. The optical laminate 11 is an optical film (also referred to as an "AG film") that scatters incident light using the fine unevenness on the surface of the antiglare layer 3 to suppress reflections of external light.

[0012] The transparent substrate 2 is a film that serves as the base of the optical laminate 11, and is made of a material that has excellent transparency to visible light. Examples of materials that can be used to form the transparent substrate 2 include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyacrylates such as polymethyl methacrylate, polyamides such as nylon 6 and nylon 66, polyimides, polyarylates, polycarbonates, triacetyl cellulose, polyacrylates, polyvinyl alcohol, polyvinyl chloride, cycloolefin copolymers, norbornene-containing resins, polyethersulfones, and transparent resins such as polysulfones, and inorganic glass. The thickness of the transparent substrate 2 is not particularly limited, but is preferably 10 to 200 μm.

[0013] The surface of the transparent substrate 2 may be subjected to a surface modification treatment in order to improve adhesion with other layers to be laminated thereon. Examples of surface modification treatments include alkali treatment, corona treatment, plasma treatment, sputtering treatment, application of a surfactant or a silane coupling agent, and Si vapor deposition.

[0014] The antiglare layer 3 is a functional layer that forms the fine uneven shape on the outermost surface of the optical laminate 11 .

[0015] The antiglare layer 3 is formed by applying a coating liquid containing an active energy ray-curable compound and organic fine particles and / or inorganic fine particles (filler) to the transparent substrate 2 and curing the coating film.

[0016] As the active energy ray-curable compound, for example, a monofunctional, difunctional, trifunctional or higher functional (meth)acrylate monomer can be used. In this specification, "(meth)acrylate" is a general term for both acrylate and methacrylate, and "(meth)acryloyl" is a general term for both acryloyl and methacryloyl.

[0017] Examples of monofunctional (meth)acrylate compounds include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, glycidyl (meth)acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and isobornyl (meth)acrylate. acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phosphate (meth)acrylate, ethylene oxide-modified phosphate (meth)acrylate, phenoxy (meth)acrylate, ethylene oxide-modified phenoxy (meth)acrylate, propylene oxide ethylene oxide-modified phenoxy (meth)acrylate, nonylphenol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, propylene oxide-modified nonylphenol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypropylene glycol (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, ) acryloyloxyethyl hydrogen phthalate, 2-(meth)acryloyloxypropyl hydrogen phthalate, 2-(meth)acryloyloxypropyl hexahydrohydrogen phthalate, 2-(meth)acryloyloxypropyl tetrahydrohydrogen phthalate, dimethylaminoethyl (meth)acrylate, trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropropyl (meth)acrylate, 2-adamantane,adamantane derivative mono(meth)acrylates such as adamantyl acrylate having a monovalent mono(meth)acrylate derived from adamantanediol, etc.

[0018] Examples of bifunctional (meth)acrylates include di(meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate, propoxylated hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and hydroxypivalic acid neopentyl glycol di(meth)acrylate.

[0019] Examples of tri- or higher functional (meth)acrylates include tri(meth)acrylates such as trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tris-2-hydroxyethyl isocyanurate tri(meth)acrylate, and glycerin tri(meth)acrylate; trifunctional (meth)acrylate compounds such as pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate;

[0033] Examples of the polyfunctional (meth)acrylate include tri- or higher functional (meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ditrimethylolpropane hexa(meth)acrylate, as well as polyfunctional (meth)acrylate compounds in which a portion of these (meth)acrylates is substituted with an alkyl group or ε-caprolactone.

[0020] Urethane (meth)acrylates can also be used as polyfunctional monomers. Examples of urethane (meth)acrylates include those obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer, and then reacting the resulting product with a (meth)acrylate monomer having a hydroxyl group.

[0021] Examples of urethane (meth)acrylates include pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, and dipentaerythritol pentaacrylate isophorone diisocyanate urethane prepolymer.

[0022] The polyfunctional monomers may be used alone or in combination of two or more. In addition, the polyfunctional monomers may be in the form of a monomer in the coating liquid, or may be in the form of a partially polymerized oligomer.

[0023] The organic fine particles are a material that mainly forms fine irregularities on the surface of the antiglare layer 3 and provides the function of diffusing external light. Resin particles made of a light-transmitting resin material such as acrylic resin, polystyrene resin, styrene-(meth)acrylic acid ester copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, or polyethylene fluoride resin can be used as the organic fine particles. Two or more types of resin particles made of different materials (refractive indexes) may be mixed and used to adjust the refractive index and dispersion of the resin particles. The average particle size of the organic fine particles is preferably 0.5 to 10 μm.

[0024] The inorganic fine particles added to the composition for forming an antiglare layer are preferably nanoparticles having an average particle size of 10 to 200 nm.

[0025] The inorganic fine particles are primarily used to adjust the sedimentation and aggregation of the organic fine particles in the antiglare layer 3. Examples of inorganic fine particles that can be used include silica fine particles, metal oxide fine particles, and various mineral fine particles. Examples of silica fine particles include colloidal silica and silica fine particles surface-modified with reactive functional groups such as (meth)acryloyl groups. Examples of metal oxide fine particles include alumina, zinc oxide, tin oxide, antimony oxide, indium oxide, titania, and zirconia. Examples of mineral fine particles include mica, synthetic mica, vermiculite, montmorillonite, iron-montmorillonite, bentonite, beidellite, saponite, hectorite, stevensite, nontronite, magadiite, ilealite, kanemite, layered titanic acid, smectite, and synthetic smectite. The mineral fine particles may be natural or synthetic (including substituted or derivative) materials, or a mixture of both may be used. Among mineral fine particles, layered organic clay is more preferred. Layered organic clay refers to a swelling clay in which organic onium ions have been introduced between its layers. The organic onium ions are not limited as long as they can be organized by utilizing the cation exchange properties of the swelling clay. When a layered organic clay mineral is used as the mineral fine particles, the above-mentioned synthetic smectite can be suitably used. Synthetic smectite has the function of increasing the viscosity of the antiglare layer-forming composition, suppressing the settling of resin particles and inorganic fine particles, and adjusting the uneven shape of the surface of the optical functional layer.

[0026] A polymerization initiator may be added to cure the antiglare layer-forming composition by ultraviolet irradiation. Polymerization initiators that generate radicals upon ultraviolet irradiation can be used. Radical polymerization initiators such as acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, and acylphosphine oxides can be used as the polymerization initiator. Examples of polymerization initiators that can be used include diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-phenylacetophenone, dibenzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, p-chlorobenzophenone, p-methoxybenzophenone, Michler's ketone, acetophenone, and 2-chlorothioxanthone. One of these initiators may be used alone, or two or more may be used in combination.

[0027] Furthermore, it is preferable to add an antifouling agent, leveling agent, oil repellent, water repellent, or fingerprint inhibitor to the composition for forming the antiglare layer as a component for improving antifouling properties. Fluorine-containing compounds and silicone compounds can be suitably used as these additives. By adding an antifouling compound to the antiglare layer 3, which is the outermost layer, the ease of wiping off fingerprints can be further improved. In addition, various additives such as antistatic agents, antifoaming agents, antioxidants, ultraviolet absorbers, infrared absorbers, colorants, light stabilizers, polymerization inhibitors, and photosensitizers may be added as needed.

[0028] Furthermore, a solvent may be added to the antiglare layer-forming composition, if necessary. Examples of the solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, butanol, isopropyl alcohol, and isobutanol; ketones such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; ketone alcohols such as diacetone alcohol; aromatic hydrocarbons such as benzene, toluene, and xylene; glycols such as ethylene glycol, propylene glycol, and hexylene glycol; glycol ethers such as ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, diethyl cellosolve, diethyl carbitol, and propylene glycol monomethyl ether; esters such as methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, and amyl acetate; ethers such as dimethyl ether and diethyl ether; and N-methylpyrrolidone and dimethylformamide, which may be used alone or in combination of two or more.

[0029] FIG. 2 is a cross-sectional view schematically illustrating another example of the optical film according to the embodiment.

[0030] The optical laminate 12 includes a transparent substrate 2, an antiglare layer (first functional layer) 3 laminated on one side of the transparent substrate 2, and a low refractive index (second functional layer) layer 4 laminated on the surface of the antiglare layer 3 and having a lower refractive index than the antiglare layer 3. The optical laminate 12 is an optical film (also referred to as an "AGLR film") that suppresses glare and reflection of external light by utilizing scattering of incident light and optical interference caused by fine irregularities on the outermost surface.

[0031] The low refractive index layer 4 has a refractive index lower than that of the underlying antiglare layer 3, and is a functional layer that suppresses reflection by optical interference.

[0032] The low refractive index layer 4 can be formed by applying a composition containing an active energy ray-curable compound to the surface of the antiglare layer 3 and curing the coating film. The low refractive index layer 4 may contain low refractive index fine particles to adjust the refractive index.

[0033] Examples of low refractive index particles include LiF, MgF, 3NaF·AlF, and AlF (each having a refractive index of 1.4), and Na３ AlF ６ Fine particles such as cryolite (refractive index 1.33) and silica fine particles having voids therein can be suitably used. Silica fine particles having voids therein can have the refractive index of the voids (approximately 1) of air, and are therefore useful for lowering the refractive index of the low refractive index layer 4. Specifically, porous silica particles and silica particles having a shell structure can be used. Note that low refractive index fine particles are not necessarily required, and if the refractive index of the active energy ray-curable compound after curing is lower than the refractive index of the antiglare layer 3, the low refractive index fine particles may be omitted.

[0034] As the active energy ray-curable compound, the polymerizable compound described in the antiglare layer can be used. In addition, the above-mentioned polymerization initiator and solvent may be appropriately added to the composition for forming the low refractive index layer.

[0035] Since the low refractive index layer 4 is a functional layer that serves as the outermost layer, it is preferable to add to the composition for forming the low refractive index layer components that improve antifouling properties, such as an antifouling agent, a leveling agent, an oil repellent, a water repellent, and an anti-fingerprint agent. Fluorine-containing compounds and silicone compounds can be suitably used as these additives. In addition, various additives such as antistatic agents, antifoaming agents, antioxidants, ultraviolet absorbers, infrared absorbers, colorants, light stabilizers, polymerization inhibitors, and photosensitizers may be added as needed.

[0036] Between the transparent substrate 2 and the antiglare layer 3, one or more other functional layers such as a hard coat layer, a high refractive index layer, a medium refractive index layer, an antistatic layer, an electromagnetic wave blocking layer, an infrared absorbing layer, an ultraviolet absorbing layer, or a color correction layer may be laminated.

[0037] The method for applying the antiglare layer-forming composition and the low refractive index layer-forming composition is not particularly limited, and for example, they can be applied using a spin coater, a roll coater, a reverse roll coater, a gravure coater, a microgravure coater, a knife coater, a bar coater, a wire bar coater, a die coater, a dip coater, a spray coater, an applicator, or the like.

[0038] Here, the surface irregularities of the optical laminate according to this embodiment will be described in detail.

[0039] The uneven shape of the outermost surface of the optically functional laminate according to this embodiment satisfies the following conditions (1) and (2): 800≦A≦5,500 (1) 0<B≦100 (2) Here, A and B are values ​​derived from the spatial frequency f calculated from a predetermined range of the image (power spectrum image) obtained by fast Fourier transforming (hereinafter referred to as "FFT") image data generated from measurement data of the unevenness height on the surface of the optical laminate. A is the average value of the power spectrum intensity in the range of 50 cycle / mm≦f≦100 cycle / mm, and B is the average value of the power spectrum intensity in the range of 200 cycle / mm≦f≦250 cycle / mm.

[0040] The values ​​of A and B are calculated as follows.

[0041] First, three-dimensional data of the height of the irregularities on the outermost surface of the optical laminate is obtained by measurement. The three-dimensional data of the irregularity height includes the position in the measurement surface and the height of the irregularities. The three-dimensional data of the height of the irregularities on the outermost surface can be measured using an optical interference method or a contact method. The obtained three-dimensional data is converted into an image (first image) in which the irregularity height is used as a pixel value. Next, an FFT is performed on the first image to obtain an image (second image) after FFT processing. Next, the X coordinate of the power spectrum within a predetermined range in the second image after FFT processing is converted into a spatial frequency f. From the obtained spatial frequency, the average values ​​of the antilogarithms of the power spectrum intensity in the ranges of 50 cycles / mm≦f≦100 cycles / mm and 200 cycles / mm≦f≦250 cycles / mm are calculated, and these are used as the values ​​A and B above.

[0042] Conventionally, in order to achieve fingerprint wiping properties, it has been common to incorporate an antifouling component such as a fluorine compound or a silicone compound into the outermost surface layer. However, there is a limit to the improvement in fingerprint wiping properties that can be achieved by simply adding an antifouling component. The inventors of the present application have found that fingerprint wiping properties are affected not only by the material and components contained in the outermost surface, but also by the surface irregularity shape. Furthermore, the inventors have investigated irregularity shapes that can improve fingerprint wiping properties, and have found that the power spectrum intensity around a spatial frequency of 50 cycles / mm is significantly related to fingerprint wiping properties, and that the higher the power spectrum intensity around a spatial frequency of 50 cycles / mm (i.e., the higher the irregularity height), the better the fingerprint wiping properties.

[0043] On the other hand, when the surface irregularities become large and the irregularities take on a lens shape, the anti-glare properties deteriorate. In other words, when the surface irregularities improve the ease of wiping off fingerprints (anti-fouling properties), the anti-glare properties decrease, and it was found that there is a trade-off between anti-fouling properties and anti-glare properties.

[0044] The optical laminates 11 and 12 according to this embodiment have excellent fingerprint wiping properties because the uneven shape of the outermost surface satisfies the above conditions (1) and (2). If either the value of A or B is outside the range of conditions (1) or (2), the fingerprint wiping properties deteriorate, or the optical properties deteriorate, such as increased haze or a whitish appearance due to increased surface scattering. The values ​​of A and B can be controlled by adjusting the particle size and amount of filler added to the antiglare layer 3, the amount of additive, the film thickness of the antiglare layer 3, and the aggregation state of the filler in the film formation process.

[0045] Furthermore, by adding an antifouling component such as an antifouling agent to the functional layer that is the outermost layer, the ease of wiping off fingerprints can be further improved.

[0046] Glare resistance can be evaluated by the value of "glare contrast" defined in JIS C1006:2019, and if the glare contrast is 3% or less, glare is not visible and the glare resistance can be evaluated as good. If the glare contrast is 3% or less, glare is not visible and the glare resistance is good.

[0047] The glare contrast can be calculated as follows: First, an image of the display screen of an image display device lit in a single color (e.g., green) is captured using an image sensor. Next, the pixel pattern is removed from the captured image using image processing to obtain two-dimensional gradation data (glare pattern). Next, the standard deviation (glare value) of all illuminance distribution data that constitute the obtained glare pattern is calculated. The glare contrast is then calculated as the percentage of the glare value relative to the average value of all illuminance distribution data that constitute the glare pattern.

[0048] The glare contrast increases as the resolution (ppi) of the image display device increases. When the glare contrast y is measured at two or more different resolutions x, and the difference between the values ​​of x and y is plotted, the linear approximation equation y = ax is obtained, and it is preferable that 0 < a < 0.015. The value of the resolution x used in the measurement includes at least values ​​selected from the ranges of 250 to 270 ppi and 500 to 520 ppi. When the coefficient a of the linear approximation equation is less than 0.015, the optical laminate has suppressed glare contrast even when used in an image display device with high resolution.

[0049] At least two plots (x and y pairs) are required when determining the linear approximation formula, but the more plots there are, the higher the approximation accuracy. Therefore, in addition to the resolution x value selected from the ranges of 250 to 270 ppi and 500 to 520 ppi, it is preferable to use the glare contrast y value measured at one or more resolutions x selected from the ranges of, for example, 80 to 99 ppi, 100 to 119 ppi, 120 to 140 ppi, and 160 to 180 ppi for the approximation.

[0050] The haze value (total haze) of the optical laminate according to the present invention is preferably 1.5 to 35%. The haze value is a value measured in accordance with JIS K7136. A haze value of less than 1.5% is not preferred because antiglare properties cannot be obtained. A haze value of more than 35% is also not preferred because the appearance becomes white.

[0051] The optical laminates 11 and 12 according to the present embodiment can be used to form an image display device by being attached to the outermost surface of an image display panel such as a liquid crystal panel or an organic EL panel. A touch panel may be provided between the optical laminates 11 and 12 and the image display panel. The optical laminates 11 and 12 according to the present embodiment have excellent fingerprint wiping properties and are therefore suitable as optical films to be provided on the outermost surface of an image display device equipped with a touch panel.

[0052] Examples of specific implementations of the present invention will be described below.

[0053] Example 1 [Anti-glare layer-forming composition] Organic fine particles having an average particle size of 3 μm (MX-300, refractive index 1.49, manufactured by Soken Chemical & Engineering Co., Ltd.) and organoclay (Sumecton SAN, manufactured by Kunimine Industries Co., Ltd.) were dispersed in toluene by stirring for 40 minutes using a paint shaker. 5.0 parts by mass of the organic fine particles, 1.0 part by mass of the organoclay, 91.0 parts by mass of pentaerythritol triacrylate (PETA, Viscoat #300, manufactured by Osaka Organic Chemical Industry Ltd.), and 3.0 parts by mass of a photopolymerization initiator (Omnirad (registered trademark) 184, manufactured by IGM Resins B.V.) were mixed in toluene to a total solids content of 50% by mass, and the mixture was stirred for 40 minutes using a paint shaker to obtain an anti-glare layer-forming composition.

[0054] A 60 μm-thick triacetyl cellulose film (TAC film, TG60 manufactured by Fujifilm Corporation) was used as a transparent substrate. The antiglare layer-forming composition was applied to one surface of the transparent substrate using a bar coater and dried in a dryer at 100° C. for 1 minute. In a nitrogen atmosphere (oxygen concentration 500 ppm or less), a high-pressure mercury UV device was used to apply an integrated exposure dose of 200 mJ / cm. ２ The coating was then cured with UV light so that an antiglare layer having a thickness of 5 μm was formed.

[0055] Example 2: As organic fine particles, 5.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 3 μm and 5.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 5.0 μm were used, and no organic clay was added. The amounts of the organic fine particles and the organic clay, which were changed from those in Example 1, were adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, a composition for forming an antiglare layer was prepared similarly to Example 1. Using the prepared composition for forming an antiglare layer, an antiglare layer having a film thickness of 8 μm was formed on one surface of a transparent substrate in the same manner as in Example 1.

[0056] Example 3: As organic fine particles, 8.0 parts by mass of organic fine particles having an average particle size of 5 μm (refractive index 1.49) and 10.0 parts by mass of organic fine particles having an average particle size of 5 μm (1.59) were used, and no organic clay was added. The amounts of the organic fine particles and the organic clay, which were changed from Example 1, were adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, a composition for forming an antiglare layer was prepared in the same manner as in Example 1. The prepared composition for forming an antiglare layer was used to form an antiglare layer having a thickness of 8 μm on one surface of a transparent substrate.

[0057] Example 4 [Composition for forming a low refractive index layer] 45.0 parts by mass of PETA, 50 parts by mass of hollow silica microparticles dispersed in isopropyl alcohol having an average particle size of 75 nm in terms of solid content, and 3.0 parts by mass of a photopolymerization initiator were added, and 2.0 parts by mass of a fluorine-based antifouling agent (KY-1203, manufactured by Shin-Etsu Chemical Co., Ltd.) was further added, and the mixture was diluted with an isopropyl alcohol solvent to a total solid content of 3.5 parts by mass, and stirred for 40 minutes with a paint shaker to obtain a composition for forming a low refractive index layer.

[0058] An antiglare layer was formed on one surface of a transparent substrate in the same manner as in Example 1. The composition for forming a low refractive index layer was applied to the surface of the antiglare layer using a bar coater and dried in a dryer at 100°C for 1 minute. A high-pressure mercury UV device was used in a nitrogen atmosphere (oxygen concentration 500 ppm or less) to irradiate the antiglare layer with an accumulated exposure dose of 200 mJ / cm. ２ The coating was UV-cured so that the optical film thickness nd (refractive index n×film thickness d) was 550 / 4 nm, thereby forming a low refractive index layer.

[0059] Example 5 An antiglare layer was formed on one surface of a transparent substrate in the same manner as in Example 1, except that 5.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 3 μm were used as the organic fine particles. Next, a low refractive index layer was formed on the antiglare layer in the same manner as in Example 4.

[0060] Example 6 Except for using 5.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 1.5 μm as the organic fine particles, an antiglare layer having a film thickness of 3 μm was formed on one surface of a transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the antiglare layer in the same manner as in Example 4.

[0061] Example 7 Except for using 5.0 parts of organic fine particles (refractive index 1.59) having an average particle size of 10.0 μm as the organic fine particles, an antiglare layer having a thickness of 12 μm was formed on one surface of a transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the antiglare layer in the same manner as in Example 4.

[0062] (Example 8) As the organic fine particles, 12.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 0.8 μm were used, and the amount of the organic fine particles was changed from that of Example 1 by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0063] (Example 9) As organic fine particles, 5.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 2.0 μm and 2.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 2.0 μm were used, and the amount of organic fine particles was changed from that of Example 1 by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0064] (Example 10) As organic fine particles, 12.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 2.0 μm and 3.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 3.0 μm were used, and the amount of organic fine particles was changed from that of Example 1 by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0065] (Example 11) As organic fine particles, 8.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 3.0 μm and 2.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 3.0 μm were used, and the amount of organic fine particles was changed from that of Example 1 by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0066] (Example 12) As the organic fine particles, 10.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 3.0 μm were used, and the amount of the organic fine particles was changed from that of Example 1 by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 5 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0067] (Example 13) As the organic fine particles, 8.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 5.0 μm were used, and the amount of the organic fine particles was changed from that of Example 1 by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 6 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0068] Comparative Example 1: 15.0 parts by mass of organic fine particles having an average particle size of 8.0 μm (refractive index 1.59) were used as the organic fine particles, and the amount of the organic fine particles was changed from that in Example 1 by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was adjusted to 100 parts by mass. Except for the above conditions, an antiglare layer having a thickness of 5 μm was formed on one surface of a transparent substrate in the same manner as in Example 1.

[0069] Comparative Example 2 The organic fine particles were changed to 2.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 3.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by increasing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of a transparent substrate in the same manner as in Example 1.

[0070] (Comparative Example 3) The organic fine particles were changed to 2.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 0.8 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by increasing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0071] (Comparative Example 4) The organic fine particles were changed to 2.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 1.5 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by increasing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0072] (Comparative Example 5) The organic fine particles were changed to 2.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 2.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by increasing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0073] (Comparative Example 6) The organic fine particles were changed to 15.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 2.0 μm and 5.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 2.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 5 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0074] (Comparative Example 7) The organic fine particles were changed to 8.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 3.0 μm and 8.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 3.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0075] (Comparative Example 8) The organic fine particles were changed to 10.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 5.0 μm and 2.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 5.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted to 100 parts by mass by reducing the amount of pentaerythritol triacrylate. Except for the above conditions, an antiglare layer having a film thickness of 6.5 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0076] (Comparative Example 9) The organic fine particles were changed to 8.0 parts by mass of organic fine particles (refractive index 1.49) having an average particle size of 15.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 17 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0077] (Comparative Example 10) The organic fine particles were changed to 12.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 3.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 4 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0078] (Comparative Example 11) The organic fine particles were changed to 12.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 5.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, HC composition 1 was prepared in the same manner as in Example 1, and an antiglare layer with a film thickness of 6.5 μm was formed in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0079] (Comparative Example 12) The organic fine particles were changed to 12.0 parts by mass of organic fine particles (refractive index 1.59) having an average particle size of 10.0 μm, and the amount of the organic fine particles changed from Example 1 was adjusted by reducing the amount of pentaerythritol triacrylate so that the total solid content other than the solvent was 100 parts by mass. Except for the above conditions, an antiglare layer having a film thickness of 12 μm was formed on one surface of the transparent substrate in the same manner as in Example 1. Next, a low refractive index layer was formed on the above antiglare layer in the same manner as in Example 4.

[0080] The optical laminates according to the examples and comparative examples were evaluated as follows.

[0081] <Evaluation 1: Surface Uneven Profile> (Acquisition of Three-Dimensional Data) Using a Vertscan (R3300H Lite, manufactured by Ryoka Systems Co., Ltd.), three-dimensional data of the uneven profile of the outermost surface of the optical laminate was measured by optical interference. The measurement conditions were as follows. The unevenness height was based on the lowest position within the measurement range. Camera model: Sony HR-50 1 / 3 Objective lens magnification: 5XTI Lens barrel: 1X Zoom lens: 1X Light source: 530 white Wavelength filter: 520 nm Measurement device: Piezo Measurement mode: Phase Scan speed: 4 μm / sec Scan range: 10 μm to -10 μm Number of effective pixels: 0% Measurement range: 940.8 μm x 705.6 μm, 640 pixels x 480 pixels XY direction resolution: 1 pixel 1.47 μm

[0082] (FFT Analysis) FFT analysis was performed using the free software "ImageJ 1.53h" in a Windows (registered trademark) 10 environment. The procedure is as follows: 1. The three-dimensional data was converted into TIFF image data with height as the pixel value. 2. FFT was performed by referencing the original three-dimensional data values ​​(measured height values). The image size after FFT processing was 1024 pixels x 1024 pixels. 3. The image after FFT processing was processed to restore the power spectrum intensity to the actual measured value. 4. A range of ±20 pixels on the positive X-axis passing through the origin was specified on the processed image, and the power spectrum intensity was output. 5. The X-coordinate of the output power spectrum was converted to spatial frequency f based on the pixel size of the original three-dimensional data. 6. From the calculated spatial frequency, the average values ​​(values ​​A and B) of the antilogarithm of the power spectrum intensity within each range of 50 cycle / mm≦f≦100 cycle / mm and 200 cycle / mm≦f≦250 cycle / mm were calculated.

[0083] The FFT of the three-dimensional data is a process for decomposing waves resulting from changes in height of the surface of the optical film into spatial frequency components.

[0084] In step 1, a grayscale image may be generated from the three-dimensional data, in which height information is represented as brightness in a predetermined range. Specifically, the grayscale image can be generated by converting the height information into a numerical value representing brightness in 256 levels, with the minimum value being 0 and the maximum value being 255. In this case, in step 2, a two-dimensional Fourier transform is performed on the obtained grayscale image. A transform that is the reverse of the transform from height information to brightness is performed on the power spectrum intensity obtained by the two-dimensional Fourier transform, thereby restoring the power spectrum intensity to a value corresponding to the height. This results in data obtained by applying a fast Fourier transform to the height information of the irregularities at each position on the surface of the optical film 10.

[0085] It should be noted that in step 1, the conversion into values ​​representing brightness may not be performed, and in step 2, the height information itself may be subjected to a two-dimensional Fourier transform.

[0086] Furthermore, the number of data points in the three-dimensional data, the number of pixels in the grayscale image, and the number of pixels in the FFT image, which is the power spectrum, are not particularly limited. For example, when performing a two-dimensional Fourier transform on a 640px x 480px image to generate a 1024px x 1024px FFT image, the 480 rows of height data are decomposed into 1024 frequencies for each row, and then the data is transposed vertically and horizontally, and the 640 columns of height data are decomposed into 1024 frequencies for each column. This results in a 1024px x 1024px FFT image.

[0087] The procedure for performing FFT analysis using the image analysis software "ImageJ 1.53h" is as follows: (1) The three-dimensional data was imported into the image analysis software as TIFF image data. (2) In the image analysis software, "FFT Options" was selected and "Raw power spectrum" was checked. Then, fast Fourier transform processing was performed. This opened an image called "FFT of (file name)" and an image called "PS of (file name)." Each image was 1024px x 1024px in size. The "FFT of (file name)" image was an image showing the power spectrum intensity normalized to 256 levels of brightness, and the "PS of (file name)" image was an image in which the power spectrum intensity was set to a value corresponding to the height of the three-dimensional data. (3) The "FFT of (filename)" image was closed, and the "Log" and "Macro..." commands, "code:v=v / 2.303;," were executed on the "PS of (filename)" image. This resulted in a logarithmic transformation of the z-axis and each value, which indicate the power spectrum intensity, using common logarithms. (4) For the image processed in (3) above, the center of the image was set as the origin, and the x-axis was set horizontally passing through the origin. A range of x > 0 and ±20 pixels vertically from the x-axis was specified, and the power spectrum intensity of each pixel was output. The average value of the power spectrum intensity for pixels with the same x-coordinate was then calculated, and this was used as the power spectrum intensity for each x-coordinate. (5) The x-coordinate of the output power spectrum intensity was converted to a spatial frequency with a unit length of 1 millimeter based on the pixel size of the three-dimensional data. (6) The intensity integral values ​​A and B were calculated from the power spectrum intensity of each spatial frequency.

[0088] <Evaluation 2. Fingerprint Wiping Efficiency Evaluation> The obtained optical laminate was attached to a blackboard using an optical pressure-sensitive adhesive with the functional surface facing up, and artificial leather with an olive oil reagent attached was pressed against the functional surface to deposit olive oil. The attached olive oil was repeatedly wiped off with tissue paper (Scottie (registered trademark), manufactured by Nippon Paper Kracie Co., Ltd.) under a load of 1 kg, and the reflectance spectrum of the olive oil-attached area was measured with a spectrophotometer (CM-2500d, manufactured by Konica Minolta) after each wipe. The color difference ΔE*ab between before and after the olive oil was applied was calculated, and the fingerprint wiping ability was evaluated according to the following criteria based on the number of wipes until the color difference ΔE*ab was 0.5 or less. 5 (very good): Number of wipes ≦ 9 times 4 (fairly good): Number of wipes < 9 times ≦ 12 times 3 (good): Number of wipes < 12 times ≦ 15 times 2 (not very good): Number of wipes < 20 times 1 (bad): Number of wipes < 20 times

[0089] The measurement conditions for the reflectance spectroscopy were as follows: Measurement diameter: Φ8 mm Item: SCI / SCE Light source: D65 UV setting: 100% Observation field: 10°

[0090] <Evaluation 3. Glare Evaluation> The obtained optical laminate was placed on metal masks with six grating patterns (85, 106, 127, 169, 254, 508 ppi) of different resolution, and the glare contrast was measured by single-image measurement using a glare meter SMS-1000 (manufactured by DM&S) (in accordance with JIS C1006:2019). The horizontal axis represents resolution and the vertical axis represents glare contrast. The measured values ​​of the resolution and glare contrast of the metal mask used were plotted, and the slope a of the linear approximation equation was calculated. Based on the calculated value of a, the glare resistance was evaluated according to the following criteria: ◎ (very good): 0<a<0.010 ○ (good): 0.010≦a<0.015 × (poor): 0.015≦a

[0091] <Evaluation 4. Evaluation of Anti-glare Property> FIG. 3 is a diagram showing a method for evaluating anti-glare property, and FIG. 4 is a diagram showing an example of evaluation of anti-glare property.

[0092] The obtained optical laminate was attached to a blackboard using an optical pressure-sensitive adhesive so that the functional surface faced outward. A three-band fluorescent lamp and the optical laminate were also placed so that light would hit the functional surface perpendicularly. The surface of the optical laminate was observed from a direction such that the line connecting the viewpoint and the image of the three-band fluorescent lamp reflected on the functional surface was at an angle of 70° to the perpendicular line from the three-band fluorescent lamp to the functional surface, and the anti-glare properties were evaluated according to the following criteria (see Figure 4). ◎: The outline of the three-band fluorescent lamp was visible, and the edges were visible but blurred. ◯: The outline of the three-band fluorescent lamp was visible, but the edges were blurred and unclear. ×: The outline of the three-band fluorescent lamp was blurred to the point where it was impossible to see, or the edges were clearly visible.

[0093] <Haze> Haze was measured using a haze meter (NDH7000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with the haze test method of JIS K 7136, which is a test method for optical properties of plastics.

[0094] Tables 1 and 2 show the evaluation results.

[0095]

[0096] As shown in Table 1, the optical laminates according to Examples 1 to 13, A and B, satisfied the conditions (1) and (2), and were excellent in all of anti-glare properties, fingerprint wiping properties, and anti-glare properties. The anti-glare properties evaluated based on the slope a of the approximation line indicate that the anti-glare properties are unlikely to deteriorate even when the resolution of the display device is increased.

[0097] On the other hand, in the optical laminates according to Comparative Examples 1 to 12, one or both of A and B did not satisfy the above conditions, and the desired anti-glare properties were not obtained, and in addition, the fingerprint wiping properties or anti-glare properties were poor.

[0098] From the above, it was confirmed that an optical laminate excellent in optical properties and fingerprint wiping-off property can be realized by simultaneously satisfying the above-mentioned conditions A to C (1) to (3).

[0099] The present invention can be used as an optical film provided on the outermost surface of an image display device.

[0100] REFERENCE SIGNS LIST 1 Optical laminate 2 Transparent substrate 3 Antiglare layer 4 Low refractive index layer

Claims

1. An optical laminate having an uneven shape on its outermost surface, characterized in that it satisfies the following conditions (1) and (2): 800≦A≦5,500 (1) 0<B≦100 (2) wherein, when three-dimensional data of unevenness height measured by an optical interference method or a contact method for the uneven shape is converted into first image data having unevenness height as a pixel value, the first image data is converted into a second image by fast Fourier transform, and the spatial frequency f of the X coordinate of the power spectrum of an image of the second image passing through the origin and within a range of ±20 pixels on the positive X axis is calculated, A: average value of power spectrum intensity in the range of 50 cycle / mm≦f≦100 cycle / mm, B: average value of power spectrum intensity in the range of 200 cycle / mm≦f≦250 cycle / mm.

2. The optical laminate according to claim 1, wherein when the glare contrast y is measured using grating patterns having two different resolutions selected from the range of resolution x of 250 to 270 ppi and the range of resolution x of 500 to 520 ppi, and the linear approximation equation obtained by plotting the values ​​of x and y is y=ax, the relationship is 0<a<0.

015.

3. The optical laminate according to claim 1, characterized in that the haze value measured in accordance with JIS K7136 is 1.5 to 35%.

4. The optical laminate described in claim 1, characterized in that the optical laminate comprises a transparent substrate and at least one functional layer laminated on at least one surface of the transparent substrate, and the uneven shape is formed by the functional layer.

5. The optical laminate described in claim 4, wherein the functional layer includes a first functional layer that forms the uneven shape, and a second functional layer that is laminated on the first functional layer and has a lower refractive index than the first functional layer.

6. The optical laminate according to claim 5, wherein the second functional layer contains an antifouling agent.

7. The optical laminate according to claim 6, wherein the antifouling agent contains a fluorine-containing compound or a silicone compound.

8. The optical laminate according to claim 5, wherein the first functional layer contains organic fine particles having a particle size of 0.5 to 10 μm.

9. An image display device comprising the optical laminate according to any one of claims 1 to 8.