Optical film

Abstract

To provide an optical film that has good anti-glare properties and suppresses the occurrence of white cast. [Solution] An optical film having an uneven surface on one side, wherein the root mean square slope RΔq of the surface having the uneven surface is 0.015 or less when the cutoff value λc is 0.08 mm in accordance with JIS B0601:2013.

Description

【Technical Field】 【0001】 The present invention relates to an optical film. 【Background Art】 【0002】 In high-definition image display devices such as LCDs and organic EL displays, optical films such as antiglare films are used to prevent external light from reflecting onto the display surface. For example, the antiglare property can be achieved by forming an uneven shape on the surface of the optical film to scatter and reflect external light. 【0003】 On the other hand, when such an optical film is attached to the display surface, the reflection and scattering components increase, and scattered light may mix into the parts that originally appear black, causing the screen to become whitish (white floating). 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2009-109702 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 An object of the present disclosure is to provide an optical film having good antiglare properties and suppressing the occurrence of white floating. 【Means for Solving the Problems】 【0006】 The present disclosure includes the following aspects. [1] An optical film having an uneven shape on one surface, wherein the root mean square slope RΔq of the surface of the optical film having the uneven shape, when the cut-off value λc is 0.08 mm in accordance with JIS B0601:2013, is 0.015 or less. 【Effects of the Invention】 【0007】 According to this disclosure, it is possible to provide an optical film with good anti-glare properties and suppressed white cast. [Brief explanation of the drawing] 【0008】 [Figure 1] This is a cross-sectional view of an optical film according to one embodiment of the present disclosure. [Figure 2] This is a cross-sectional view of a display device according to one embodiment of the present disclosure. [Figure 3] This is a cross-sectional view of a display device according to one embodiment of the present disclosure. [Figure 4] This is a cross-sectional view of an optical member according to one embodiment of the present disclosure. [Figure 5] This is a cross-sectional view of an optical member according to one embodiment of the present disclosure. [Figure 6] This is a cross-sectional view of a display device according to one embodiment of the present disclosure. [Modes for carrying out the invention] 【0009】 An embodiment of the present invention will be described below with reference to the accompanying drawings. The embodiment described below is illustrative and will not be construed as limiting. Each embodiment disclosed herein can be combined with any other features disclosed herein. If multiple upper and lower limits are given for a particular parameter, any combination of these upper and lower limits can be used to create a suitable numerical range. The lower and / or upper limits of the numerical ranges described herein may be replaced with numerical values ​​within that range, as shown in the examples. The expression "X~Y" indicating a numerical range means "X or greater and Y or less". If a particular description given for one embodiment also applies to other embodiments, that description may be omitted in the other embodiments. 【0010】 [Optical film] The optical film will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view of an optical film 2 according to one embodiment of the present disclosure. Figure 2 is a cross-sectional view of a display device 1 equipped with the optical film 2. As shown in Figure 1, the optical film 2 comprises a light-transmitting substrate 3 and an anti-glare layer 4. The surface 2a of the optical film 2 on the side of the anti-glare layer 4 has an uneven surface. The uneven surface preferably covers at least 90% of the surface of the optical film 2 that has the uneven surface, more preferably at least 95% of the surface, and even more preferably the entire surface. In the display device 1 shown in Figure 2, the optical film 2 is mounted on the display surface 16a. The optical film 2 mounted on the display device 1 performs several functions. The optical film 2 scatters incident light incident on the display surface 16a to prevent glare. The optical film 2 also protects the display surface 16a from external light. The light-transmitting substrate 3 is arranged to cover the display surface 16a and supports the anti-glare layer 4. In this embodiment, the light-transmitting substrate 3 covers the entire surface of the display surface 16a. 【0011】 The anti-glare layer 4 is placed on top of the light-transmitting substrate 3. The surface 4a of the anti-glare layer 4 opposite to the light-transmitting substrate 3 has a predetermined uneven shape. In one embodiment, the uneven shape preferably covers at least 90% of the surface of the anti-glare layer 4 that has the uneven shape, more preferably at least 95% of the surface, and even more preferably the entire surface. The surface 4a of the anti-glare layer 4 may also be exposed to the outside. The anti-glare layer 4 imparts anti-glare properties to the optical film 2 and scatters and reflects incident light from the outside to prevent unwanted reflections on the display surface 16a. The anti-glare layer 4 also functions as a hard coat (HC) layer that protects the display surface 16a. 【0012】 The optical film 2 is adjusted such that the root mean square slope RΔq of the surface 2a of the optical film 2 is 0.015 or less when the cut-off value λc is 0.08 mm in accordance with JIS B0601:2013. In one embodiment, it is preferably adjusted such that the root mean square slope RΔq is 0.010 or less, more preferably adjusted such that it is 0.008 or less, and even more preferably adjusted such that it is 0.007 or less. By adjusting so that the root mean square slope RΔq is 0.015 or less, the inclination angle of the convex portion of the uneven shape becomes small, and it is presumed that the occurrence of white floating is suppressed by suppressing the scattering to a wide angle. 【0013】 The root mean square slope RΔq is defined in JIS B0601:2001 and represents the root mean square of the local slope at the reference length. The measurement of the root mean square slope RΔq can be performed, for example, in accordance with JIS B 0601:2013, using a contact surface roughness meter ("Surfcom 1400G" manufactured by Tokyo Seimitsu Co., Ltd.) under the following conditions. · Cut-off wavelength λc = 0.08 mm · Cut-off ratio λc / λs = 30 · Stylus: Diamond-made with a tip radius of 2 μm and a vertex angle of 60° conical · Stylus feed speed = 0.1 mm / sec · Evaluation length: 5 times the cut-off value λc · Preparatory length: (Cut-off value λc) × 2 · Type of cut-off filter: Gaussian The adjustment method of the root mean square slope RΔq can be performed by adjusting the type of phase separation material to be combined, the drying conditions of the solvent, the particle size and amount of the fine particles contained in the antiglare layer, the thickness of the antiglare layer, and the like. 【0014】 In one embodiment, it is preferable that the ratio (hereinafter, also simply referred to as "ratio") of the sum of the reflected light intensities at -5° to -2° and 2° to 5° to the sum of the reflected light intensities with a difference from the incident angle in the goniophotometer measurement on the surface 2a of the optical film 2 is 8% or less. This ratio is more preferably 5% or less, and even more preferably 2% or less. The ratio of the sum of the reflected light intensities at -5° to -2° and 2° to 5° to the sum of the reflected light intensities with a difference from the incident angle can be regarded as indicating the ratio of the wide-angle scattering component to the total scattered light intensity. Therefore, if the ratio of the sum of the reflected light intensities at -5° to -2° and 2° to 5° to the sum of the reflected light intensities with a difference from the incident angle is 8% or less, it means that there are substantially few wide-angle scattering components with respect to the total scattered light intensity, and it can be evaluated that the occurrence of white floating is suppressed. 【0015】 The ratio can be measured using a goniophotometer, for example, a commercially available automatic variable-angle photometer (GP-200 type, manufactured by Murakami Color Technology Co., Ltd.). For example, the angular distribution of the light transmitted through the optical film 2 can be measured using a measuring device including a laser light source such as a He-Ne laser and a light receiver installed in the goniophotometer. Note that the laser light from the laser light source is irradiated onto the optical film 2 through an ND filter, and the scattered light from the sample is detected by a detector (light receiver) that can change the angle at a scattering angle θ with respect to the optical path of the laser light and includes a photomultiplier tube, and the relationship between the scattering intensity and the scattering angle θ is measured. As such a device, a laser light scattering automatic measuring device (manufactured by Nippon Scientific Engineering Co., Ltd.) can be used. 【0016】 In one embodiment, the 10-point average roughness RzJIS of the surface 2a of the optical film 2 is preferably 0.2 μm or more, more preferably 0.2 μm or more and 0.6 μm or less, and even more preferably 0.2 μm or more and 0.25 μm or less. If the 10-point average roughness RzJIS is 0.2 μm or more, it can be evaluated as having good anti-glare properties. In this embodiment, the 10-point average roughness RzJIS is the value obtained when the cutoff value λc is 0.8 mm in accordance with JIS B0601:2013. Specifically, it can be measured under the following conditions. • Cutoff wavelength λc = 0.8 mm • Cutoff ratio λc / λs = 300 • Stylus: Diamond, conical shape, tip radius 2 μm, apex angle 60° • Stylus feed rate = 0.1 mm / sec • Evaluation length: 5 times the cutoff value λc • Reserve length: (cutoff value λc) × 2 • Cutoff filter type: Gaussian The 10-point average roughness RzJIS tends to increase when surface roughness is formed using phase separation. This is achieved by increasing the difference in solubility parameters (SP values) of multiple polymer components or by increasing the molecular weight, thereby increasing repulsive interactions and emphasizing the phase separation structure, resulting in the formation of uneven surfaces with varying heights. In the case of surface roughness formation using a matrix resin and fine particles, the 10-point average roughness RzJIS tends to increase by increasing the particle size of the fine particles, decreasing the film thickness, or inducing aggregation, thereby forming an uneven surface on the anti-glare layer. In the case of molding using a mold, the 10-point average roughness RzJIS can be adjusted by controlling the surface irregularities of the mold. 【0017】 In one embodiment, the haze of the optical film 2 is preferably 10% or less, more preferably 3.0% or less, and even more preferably 1.0% or less. If the haze is 10% or less, it can be evaluated as having good transparency. The haze can be measured using a haze meter in accordance with the method specified in JIS K7136:2000. In the case of surface formation using phase separation, haze tends to increase by increasing the difference in solubility parameters (SP values) of multiple polymer components, increasing the molecular weight to increase repulsive interactions, emphasizing the phase separation structure and forming uneven surfaces with height differences, or by increasing the amount of polymer components to increase the unevenness density. In the case of surface formation using matrix resin and fine particles, haze tends to increase by increasing the particle size of the fine particles, decreasing the film thickness, causing aggregation to form an uneven surface on the anti-glare layer, or by increasing the amount of fine particles to increase the unevenness density. In the case of molding using a mold, haze can be controlled by adjusting the unevenness of the mold. 【0018】 The following describes specific examples of the light-transmitting substrate 3 and the anti-glare layer 4. (Light transparent base material) Examples of materials for the light-transmitting substrate 3 include glass, ceramics, and resin. The same resin used for the anti-glare layer 4 can be used for the light-transmitting substrate 3. Preferred materials for the light-transmitting substrate 3 include transparent polymers, such as cellulose derivatives (cellulose triacetate (TAC), cellulose diacetate, and other cellulose acetates), polyester resins (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyarylate resins, etc.), polysulfone resins (polysulfone, polyethersulfone (PES), etc.), polyetherketone resins (polyetherketone (PEK), polyetheretherketone (PEEK), etc.), polycarbonate resins (PC), polyolefin resins (polyethylene, polypropylene, etc.), cyclic polyolefin resins (film "ARTON" (registered trademark) manufactured by JSR Corporation, film "ZEONEX" (registered trademark) manufactured by Nippon Zeon Co., Ltd., etc.), halogen-containing resins (polyvinylidene chloride, etc.), (meth)acrylic resins, styrene resins (polystyrene, etc.), vinyl acetate or vinyl alcohol resins (polyvinyl alcohol, etc.). 【0019】 The light-transmitting substrate 3 may be uniaxially or biaxially stretched, but it is preferably optically isotropic and has a low refractive index. An example of an optically isotropic light-transmitting substrate 3 is an unstretched film. 【0020】 The thickness of the light-transmitting substrate 3 can be set as appropriate, but it is preferably in the range of 5 μm to 2000 μm, more preferably in the range of 15 μm to 1000 μm, and even more preferably in the range of 20 μm to 500 μm. 【0021】 (Anti-glare layer) The anti-glare layer 4 has a predetermined uneven surface shape. The uneven surface shape of the anti-glare layer can be formed by, for example, (A) a method using phase separation, (B) a method using a matrix resin and fine particles, (C) a method using a mold, (D) a shot blasting method, or (E) etching. 【0022】 • First Embodiment The anti-glare layer 4 according to the first embodiment of this disclosure has a phase separation structure of multiple resin components. The anti-glare layer 4 has, for example, a surface 4a on which multiple protrusions are dispersed. As a result, the surface 4a of the anti-glare layer 4 of this embodiment has a sea-island structure formed by multiple protrusions and recesses between them. The anti-glare layer 4 exhibits anti-glare properties due to the uneven shape formed by multiple protrusions and recesses between them. By having such an anti-glare layer 4, the optical film 2 has an excellent balance between haze and transmitted image clarity (image quality). The surface 4a of the anti-glare layer 4 may have a co-continuous phase structure in which multiple protrusions are densely arranged. 【0023】 The phase separation structure of the anti-glare layer 4 according to the first embodiment is formed by spinodal decomposition (wet spinodal decomposition) from the liquid phase using the solution that serves as the raw material for the anti-glare layer 4, as will be described later. For details of the anti-glare layer 4 according to this embodiment, see, for example, Japanese Patent Application Publication No. 2014-085371. 【0024】 The multiple resin components contained in the anti-glare layer 4 according to this embodiment only need to be phase-separable. Examples of polymers contained in the anti-glare layer 4 include thermoplastic resins. Examples of thermoplastic resins include styrene resins, (meth)acrylic resins, organic acid vinyl ester resins, vinyl ether resins, halogen-containing resins, olefin resins (including alicyclic olefin resins), polycarbonate resins, polyester resins, polyamide resins, thermoplastic polyurethane resins, polysulfone resins (polyethersulfone, polysulfone, etc.), polyphenylene ether resins (polymers of 2,6-xylenol, etc.), cellulose derivatives (cellulose esters, cellulose carbamates, cellulose ethers, etc.), silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubber or elastomers (diene rubbers such as polybutadiene and polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic rubber, urethane rubber, silicone rubber, etc.). These thermoplastic resins can be used individually or in combination of two or more types. 【0025】 Examples of polymers include those having functional groups that participate in the curing reaction, or functional groups that react with curable compounds. These polymers may have functional groups in their main chain or side chains. 【0026】 The aforementioned functional groups include condensing groups and reactive groups (e.g., hydroxyl groups, acid anhydride groups, carboxyl groups, amino or imino groups, epoxy groups, glycidyl groups, isocyanate groups), and polymerizable groups (e.g., vinyl, propenyl, isopropenyl, butenyl, allyl groups, etc.). 2-6 C groups such as alkenyl groups, ethynyl, propynyl, and butynyl groups. 2-6 C such as alkynyl groups and vinylidene groups. 2-6 Examples of functional groups include alkenylidene groups, or groups having polymerizable groups such as (meth)acryloyl groups. Of these functional groups, polymerizable groups are preferred. 【0027】 Furthermore, the anti-glare layer 4 may contain multiple types of polymers. Each of these polymers may be phase-separable by spinodal decomposition from the liquid phase, or they may be incompatible with each other. The combination of the first polymer and the second polymer contained in the multiple types of polymers is not particularly limited, but those that are incompatible with each other at or near the processing temperature can be used. 【0028】 For example, if the first polymer is a (meth)acrylic resin (such as polymethyl methacrylate), the second polymer may be a cellulose derivative (for example, cellulose esters such as cellulose acetate propionate), a styrene resin (such as polystyrene or styrene-acrylonitrile copolymer), an alicyclic olefin resin (such as a polymer with norbornene as a monomer), a polycarbonate resin, or a polyester resin (poly-C 2-4 Examples include alkylene arylate-based copolyesters, etc. 【0029】 Furthermore, for example, if the first polymer is a cellulose derivative (e.g., cellulose esters such as cellulose acetate propionate), the second polymer may be a styrene resin (polystyrene, styrene-acrylonitrile copolymer, etc.), a (meth)acrylic resin, an alicyclic olefin resin (polymer with norbornene as a monomer, etc.), a polycarbonate resin, or a polyester resin (poly-C 2-4 Examples include alkylene arylate-based copolyesters, etc. 【0030】 Multiple types of polymers include at least cellulose esters (e.g., cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, etc.). 2-4 It may contain alkylcarboxylic acid esters. 【0031】 Here, the phase separation structure of the anti-glare layer 4 is fixed when the precursor of the curable resin contained in multiple resin components is cured by active energy rays (ultraviolet rays or electron beams, etc.) or heat during the manufacturing of the anti-glare layer 4. Furthermore, this curable resin imparts scratch resistance and durability to the anti-glare layer 4. 【0032】 From the viewpoint of obtaining scratch resistance for the anti-glare layer 4, it is desirable that at least one polymer included in the multiple types of polymers is a polymer having a functional group in its side chain that can react with a curable resin precursor. In addition to the two mutually immiscible polymers described above, thermoplastic resins and other polymers may be included as polymers that form a phase separation structure. The weight ratio M1 / M2 of the weight M1 of the first polymer to the weight M2 of the second polymer, and the glass transition temperature of the polymer can be set as appropriate. 【0033】 Examples of curable resin precursors include curable compounds that have functional groups that react to active energy rays (such as ultraviolet rays or electron beams) or heat, and which harden or crosslink to form a resin (particularly a cured resin or a crosslinked resin) through these functional groups. 【0034】 Examples of such compounds include thermosetting compounds or thermosetting resins (low molecular weight compounds having epoxy groups, polymerizable groups, isocyanate groups, alkoxysilyl groups, silanol groups, etc. (e.g., epoxy resins, unsaturated polyester resins, urethane resins, silicone resins, etc.)), and photocurable (ionizing radiation curable) compounds that harden with ultraviolet light or electron beams (UV-curable compounds such as photocurable monomers and oligomers). 【0035】 Examples of desirable curable resin precursors include photocurable compounds that cure quickly using ultraviolet light or electron beams. Of these, ultraviolet-curable compounds are particularly practical. To improve resistance to abrasion and other properties, it is desirable that the photocurable compound has two or more polymerizable unsaturated bonds in its molecule (preferably 2 to 15, and even more preferably about 4 to 10). Specifically, it is desirable that the photocurable compound be epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, silicone (meth)acrylate, or a polyfunctional monomer having at least two polymerizable unsaturated bonds. 【0036】 Curable resin precursors may contain curing agents depending on their type. For example, thermosetting resin precursors may contain curing agents such as amines and polycarboxylic acids, and photocurable resin precursors may contain photopolymerization initiators. Examples of photopolymerization initiators include conventional components such as acetophenones or propiophenones, benzyl compounds, benzoins, benzophenones, thioxanthones, and acylphosphine oxides. 【0037】 Furthermore, the curable resin precursor may contain a curing accelerator. For example, the photocurable resin precursor may contain a photocuring accelerator, such as tertiary amines (dialkylaminobenzoic acid esters, etc.) or phosphine-based photopolymerization accelerators. 【0038】 In the manufacturing process of the anti-glare layer 4, at least two components from the polymer and curable resin precursor contained in the solution that will be the material for the anti-glare layer 4 are used in a combination that undergoes phase separation from each other near the processing temperature. Examples of combinations to undergo phase separation include (a) a combination in which multiple types of polymers undergo phase separation in an immiscible manner, (b) a combination in which a polymer and a curable resin precursor undergo phase separation in an immiscible manner, or (c) a combination in which multiple curable resin precursors undergo phase separation in an immiscible manner. Of these combinations, (a) a combination of multiple types of polymers and (b) a combination of polymer and a curable resin precursor are usually preferred. In particular, (a) a combination of multiple types of polymers is desirable. 【0039】 Here, typically, the polymer and the cured resin or crosslinked resin produced by the curing of the curable resin precursor have different refractive indices. Also, typically, the refractive indices of multiple types of polymers (the first polymer and the second polymer) also differ from each other. The refractive index difference between the polymer and the cured resin or crosslinked resin, and the refractive index difference between multiple types of polymers (the first polymer and the second polymer), is preferably in the range of 0 to 0.04, and more preferably in the range of 0 to 0.02. 【0040】 The anti-glare layer 4 may contain a matrix resin having a phase-separated structure and a plurality of fine particles (fillers) dispersed in the matrix resin. The fine particles may be either organic or inorganic. The anti-glare layer 4 may contain multiple types of fine particles with different materials or average particle sizes. 【0041】 Examples of organic microparticles include cross-linked acrylic particles and cross-linked styrene particles. Examples of inorganic microparticles include silica (SiO2), zirconia (ZrO2), titania (TiO2), and various other metal oxides. Examples of metal oxides include indium tin oxide, tin oxide, indium oxide, germanium oxide, zinc oxide, and aluminum oxide. Examples of inorganic microparticles include metal fluoride particles, metal sulfide particles, metal nitride particles, and metal particles. The microparticles included in the anti-glare layer 4 are preferably those with good transparency. For example, if the microparticles contain silica, it becomes easier to improve the hardness of the optical film 2. The refractive index difference between the microparticles in the anti-glare layer 4 and the matrix resin can be set to a value in the range of 0 to 0.5, for example. This refractive index difference is preferably in the range of 0 to 0.3, and more preferably in the range of 0 to 0.2. 【0042】 The average particle size of the fine particles is not particularly limited and can be set to a value in the range of 0.5 μm to 10 μm, for example. Preferably, this average particle size is in the range of 0.5 μm to 8.0 μm, and more preferably in the range of 1.0 μm to 6.0 μm. 【0043】 The average particle size is, for example, the volume-average particle size (MV value) measured by laser diffraction scattering (the same applies to the average particle size mentioned below). The fine particles may be solid or hollow. For example, setting the average particle size of the fine particles to a value that is not too small makes it easier to achieve anti-glare properties. 【0044】 The thickness of the anti-glare layer 4 can be set as appropriate, but is, for example, in the range of 0.3 μm to 20 μm. Preferably, the thickness is in the range of 1 μm to 15 μm, and more preferably in the range of 1 μm to 10 μm. Typically, the thickness can be set to a value in the range of 2 μm to 10 μm (particularly in the range of 3 μm to 7 μm). 【0045】 The anti-glare layer 4 may contain conventional additives, such as organic or inorganic particles, stabilizers (antioxidants, UV absorbers, etc.), surfactants, water-soluble polymers, fillers, crosslinking agents, coupling agents, colorants, flame retardants, lubricants, waxes, preservatives, viscosity modifiers, thickeners, leveling agents, defoaming agents, etc., to the extent that they do not impair the optical properties. 【0046】 As an example, the method for manufacturing the optical film 2 includes a preparation step of preparing a solution (hereinafter also simply referred to as the solution) that will be the material for the anti-glare layer 4; a forming step of applying the solution prepared in the preparation step to the surface of a predetermined support (in this embodiment, a light-transmitting substrate 3), evaporating the solvent in the solution, and forming a phase-separated structure by spinodal decomposition from the liquid phase; and a curing step of curing a curable resin precursor after the forming step. 【0047】 In the preparation step, a solution is prepared containing a solvent and a resin composition for constituting the anti-glare layer 4. The solvent can be selected according to the type and solubility of the polymer and curable resin precursor contained in the anti-glare layer 4 as described above. The solvent should be capable of uniformly dissolving at least the solid components (multiple types of polymers and curable resin precursors, reaction initiators, and other additives). 【0048】 Examples of solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc. Mixed solvents may also be used. 【0049】 The resin composition is preferably a composition comprising the thermoplastic resin, a photocurable compound, a photopolymerization initiator, the thermoplastic resin, and the photocurable compound. Alternatively, the resin composition is preferably a composition comprising the multiple types of mutually immiscible polymers, a photocurable compound, and a photopolymerization initiator. 【0050】 The concentration of solutes in the solution (polymers and curable resin precursors, reaction initiators, and other additives) can be adjusted within a range that allows for phase separation of multiple resin components and does not impair the flowability or coating properties of the solution. 【0051】 Here, the external haze, internal haze, and anti-glare properties of the anti-glare layer 4 can change depending on the combination and weight ratio of the resin composition in the solution, or the construction conditions of the preparation, formation, and curing processes. Therefore, by forming the anti-glare layer under varying conditions and pre-measuring and understanding the physical properties of the resulting anti-glare layer, an optical film 2 with the desired physical properties can be manufactured. 【0052】 In the forming process, the solution prepared in the preparation process is cast or coated onto the surface of a support (here, a light-transmitting substrate 3 as an example). Examples of casting or coating methods for the solution include conventional methods such as spray, spinner, roll coater, air knife coater, blade coater, rod coater, reverse coater, bar coater, comma coater, dip, dip-squeeze coater, die coater, gravure coater, microgravure coater, and silkscreen coater. 【0053】 The solvent is removed from the solution cast or coated onto the surface of the support by evaporation. During this evaporation process, the concentration of the solution causes phase separation by spinodal decomposition of multiple resin components from the liquid phase, forming a phase-separated structure. The uneven surface 4a formed by this phase-separated structure can be created by setting drying conditions and formulations that increase the melt-fluidity of the resin components after solvent evaporation to a certain extent. 【0054】 For example, evaporation of the solvent is preferably carried out by heating and drying, as this facilitates the formation of protrusions on the surface 4a of the anti-glare layer 4. By adjusting the drying temperature so that it is not too low and the drying time so that it is not too short, sufficient heat is supplied to the resin component, preventing a decrease in the melt fluidity of the resin component and making it easier to form protrusions. 【0055】 On the other hand, if the drying temperature is too high or the drying time is too long, the convex portions that have been formed may flow and their height may decrease, but the structure of the convex portions will be maintained. Therefore, drying temperature and drying time can be used as a means to adjust the anti-glare properties and slipperiness of the anti-glare layer 4 by changing the height of the convex portions. 【0056】 As phase separation progresses due to spinodal decomposition of multiple resin components from the liquid phase, a co-continuous phase structure is formed and coarsens, causing the continuous phase to become discontinuous, and a droplet phase structure (sea-island structure of independent phases such as spherical, sphere-like, disc-like, or ellipsoidal) is formed. Depending on the degree of phase separation, intermediate structures between the co-continuous phase structure and the droplet phase structure (phase structures in the transition from the co-continuous phase to the droplet phase) can also be formed. After solvent removal, a layer with fine irregularities is formed on the surface. 【0057】 In this way, by forming a fine uneven surface on the layer through phase separation, the haze of the anti-glare layer 4 can be adjusted without dispersing fine particles within the anti-glare layer 4. Furthermore, by omitting the fine particles, it becomes easier to adjust the haze of the anti-glare layer 4 while suppressing internal haze compared to external haze. Note that by adding fine particles to the solution during the preparation process, an anti-glare layer 4 containing fine particles can also be formed. 【0058】 In the curing process, the curable resin precursor in the solution is cured to immobilize the phase-separated structure formed in the formation process, thereby forming the anti-glare layer 4. The curing of the curable resin precursor is performed by heating, irradiation with active energy rays, or a combination of these methods, depending on the type of curable resin precursor. The active energy rays used for irradiation are selected according to the type of photocurable component, etc. 【0059】 Irradiation with active energy rays may be carried out in an inert gas atmosphere. When the active energy rays are ultraviolet rays, a far-ultraviolet lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp, a laser light source (such as a helium-cadmium laser or an excimer laser) can be used as the light source. 【0060】 When forming the adhesive layer 5, after preparing a solution containing an adhesive component, the adhesive layer 5 can be formed by applying and drying the solution to the other surface of the light-transmitting substrate 3 using a conventional method, such as the casting method or coating method described above in the formation process. By going through the above steps, the optical film 2 is manufactured. 【0061】 The basic method for forming the anti-glare layer is not particularly limited to the method described above, and known methods can be used. Examples of such known methods include the formation method based on the phase separation structure of the multiple resin components described above, as well as the formation method based on a fine particle dispersion method that forms the anti-glare layer 4 using a matrix resin 40 and multiple fine particles 41, as described in the following embodiments. The following describes other embodiments, focusing on the differences from the above embodiments. 【0062】 • Second embodiment The anti-glare layer 4 according to the second embodiment of this disclosure comprises a matrix resin 40 and a plurality of fine particles 41 dispersed in the matrix resin 40. Thus, the anti-glare layer 4 has a fine particle dispersion structure. Some of the fine particles 41 dispersed in the matrix resin 40 in the anti-glare layer 4 are arranged to protrude from the surface of the matrix resin 40 to the outside, thereby forming an uneven shape on the surface 4a of the anti-glare layer 4. 【0063】 Even when multiple fine particles 41 are used to form the uneven surface 4a of the anti-glare layer 4, as in this embodiment, by selecting materials such that the repulsive interaction between the fine particles 41 and other resins and solvents is strengthened during the formation of the anti-glare layer 4, appropriate aggregation of the fine particles 41 can be induced, and a distribution structure of steep and number-density irregularities can be formed on the surface 4a of the anti-glare layer 4. 【0064】 The shape of the fine particles 41 is not limited; they may be perfectly spherical or ellipsoidal. Furthermore, the fine particles 41 are solid, but may also be hollow. If the fine particles 41 are hollow, the hollow portion of the fine particles 41 may be filled with air or other gas. The anti-glare layer 4 may contain individual fine particles 41 dispersed as primary particles, or it may contain multiple secondary particles formed by the aggregation of multiple fine particles 41. 【0065】 The refractive index difference between the matrix resin 40 and the fine particles 41 is set to a value in the range of 0 to 0.5. Preferably, this refractive index difference is in the range of 0 to 0.3, and more preferably in the range of 0 to 0.2. 【0066】 The fine particles 41 are set to have an average particle size in the range of 0.5 μm to 10 μm. Preferably, the average particle size of the fine particles 41 is in the range of 0.5 μm to 8.0 μm, and more preferably in the range of 1.0 μm to 6.0 μm. Two or more types of fine particles 41 having different average particle sizes may also be used. In one embodiment, fine particles 41 with an average particle size of 0.5 μm to less than 4 μm and fine particles 41 with an average particle size of 0.5 μm to 10 μm can be used in combination. In that case, the mass ratio of each fine particle 41 is preferably 1:5 to 5:1, more preferably 1:4 to 4:1, and even more preferably 1:3 to 3:1. 【0067】 Furthermore, for example, it is desirable that the variation in particle size of the fine particles 41 be small. In this case, for example, in the particle size distribution of the fine particles 41 contained in the anti-glare layer 4, it is desirable that the average particle size of 50% or more by weight of the fine particles 41 contained in the anti-glare layer 4 is kept within a variation of 1.0 μm or less. When using two or more types of fine particles 41 with different average particle sizes, it is desirable that the variation in particle size of each fine particle 41 be small. 【0068】 In this way, the fine particles 41, whose particle size is relatively uniform and whose average particle size is set within the above range, form uniform and appropriate irregularities on the surface of the anti-glare layer 4. The ratio of the weight of the matrix resin 40 in the anti-glare layer 4 to the total weight of the multiple fine particles 41 can be set as appropriate. In this embodiment, the ratio G2 / G1 of the weight G1 of the matrix resin 40 in the anti-glare layer 4 to the total weight G2 of the multiple fine particles 41 is set, for example, to a value in the range of 0.01 to 2.0. The ratio G2 / G1 is preferably in the range of 0.02 to 1.5, and more preferably in the range of 0.03 to 1.0. 【0069】 The fine particles 41 dispersed in the matrix resin 40 may be either inorganic or organic. For example, the fine particles 41 should preferably have good transparency. Examples of organic fine particles include plastic beads. Examples of plastic beads include styrene beads (refractive index 1.59), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), acrylic-styrene beads (refractive index 1.54), polycarbonate beads, polyethylene beads, etc. The styrene beads may be cross-linked styrene beads, and the acrylic beads may be cross-linked acrylic beads. It is preferable that the plastic beads have hydrophobic groups on their surface. Examples of such plastic beads include styrene beads. 【0070】 In this embodiment, the thickness dimension of the anti-glare layer 4 can be set as appropriate, but it is preferably in the range of 0.3 μm to 20 μm, more preferably in the range of 1 μm to 15 μm, and even more preferably in the range of 1 μm to 10 μm. The thickness dimension can usually be set to a value in the range of 2 μm to 10 μm (particularly in the range of 3 μm to 7 μm). 【0071】 Examples of the matrix resin 40 include at least one of the following: a photocurable resin that hardens with active energy rays, a solvent-drying resin that hardens by the drying of a solvent added during coating, and a thermosetting resin. 【0072】 Examples of photocurable resins include those having acrylate-based functional groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, oligomers such as (meth)arylates of polyfunctional compounds like polyhydric alcohols, prepolymers, and reactive diluents. 【0073】 Specific examples of these include monofunctional monomers such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene, and N-vinylpyrrolidone, as well as polyfunctional monomers such as polymethylolpropane tri(meth)acrylate, hexanediol (meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. 【0074】 When the photocurable resin is an ultraviolet-curable resin, it is desirable to use a photopolymerization initiator. Examples of photopolymerization initiators include acetophenones, benzophenones, Michler-benzoyl benzoate, α-amyloxime esters, tetramethylthiuram monosulfide, and thioxanthones. It is also desirable to use a photosensitizer mixed with the photocurable resin. Examples of photosensitizers include n-butylamine, triethylamine, and poly-n-butylphosphine. 【0075】 Examples of solvent-drying resins include known thermoplastic resins. These thermoplastic resins include styrene resins such as polystyrene resin, acrylic resins, (meth)acrylic resins, vinyl resins such as vinyl acetate resin, vinyl ether resins, acetal resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins, cellulose resins, cellulose derivatives, silicone resins, and rubber or elastomers. As solvent-drying resins, those that are soluble in organic solvents and have particularly excellent moldability, film-forming properties, transparency, and weather resistance are desirable. Examples of such solvent-drying resins include styrene resins, (meth)acrylic resins, alicyclic olefin resins, polyester resins, and cellulose derivatives (cellulose esters, etc.). 【0076】 Examples of thermosetting resins include phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, unsaturated polyester resins, polyurethane resins, epoxy resins, amino alkyd resins, melamine-urea cocondensation resins, silicon resins, and polysiloxane resins. When a thermosetting resin is used as the matrix resin 40, at least one of the following may be used in combination: a curing agent such as a crosslinking agent or polymerization initiator, a polymerization accelerator, a solvent, and a viscosity modifier. 【0077】 A method for manufacturing an optical film 2 equipped with an anti-glare layer 4 according to this embodiment includes, as an example, a preparation step of preparing a solution to be made from the anti-glare layer 4, a coating step of applying the solution prepared in the preparation step to the surface of a predetermined support (in this embodiment, a light-transmitting substrate 3), and a curing step of curing the resin in the coated solution. 【0078】 In the preparation step, a solution is prepared containing a solvent, a resin composition for constituting the anti-glare layer 4, and fine particles 41. Examples of solvents include at least one of the following: alcohols (isopropyl alcohol, methanol, ethanol, etc.), ketones (methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), halogenated hydrocarbons, and aromatic hydrocarbons (toluene, xylene, etc.). A known leveling agent may be added to the solution. For example, by using a fluorine-based or silicone-based leveling agent, good scratch resistance can be imparted to the anti-glare layer 4. 【0079】 In the coating step, the solution prepared in the preparation step is cast or coated onto the surface of a support (here, a light-transmitting substrate 3 as an example) in the same manner as in the first embodiment. The solvent is removed from the solution cast or coated onto the surface of the support by evaporation through drying. 【0080】 If the matrix resin 40 is a photocurable resin, a curing process using ultraviolet light or electron beam is performed after the coating process, for example. Examples of ultraviolet light sources include various mercury lamps, ultraviolet carbon arc lamps, black lights, and metal halide lamps. Examples of ultraviolet wavelength ranges include, for example, the range of 190 nm to 380 nm. 【0081】 Examples of electron sources include well-known electron beam accelerators. Specifically, examples include various types of electron beam accelerators such as Van de Graaff type, Cockcroft-Walton type, resonant transformer type, isolated core transformer type, linear type, dynamitron type, and high-frequency type. 【0082】 As the matrix resin 40 contained in the solution hardens, the positions of the fine particles 41 within the matrix resin 40 are fixed. As a result, multiple fine particles 41 are dispersed within the matrix resin 40, forming an anti-glare layer 4 with a structure in which the surface 4a has an uneven shape formed by the fine particles 41. 【0083】 As another basic method for forming an anti-glare layer, a transfer formation method can be exemplified, in which the surface irregularities are transferred to a pre-prepared mold (master mold) to form the anti-glare layer. In this case, for example, a mold can be made by forming a metal film on an optical film that has been manufactured in advance by electrodeposition coating or the like. Another basic method for forming an anti-glare layer is to create irregularities on the surface of the anti-glare layer by cutting the surface of the anti-glare layer material using a laser or the like. Furthermore, a method can be exemplified in which irregularities are created on the surface of the anti-glare layer by polishing the anti-glare layer material using a shot blasting method with projection materials such as sand or beads. Finally, a method can be exemplified in which irregularities are created on the surface of the anti-glare layer by etching the anti-glare layer material. 【0084】 (Other layers) In one embodiment, the optical film 2 may further have an adhesive layer 5 on the side facing the light-transmitting substrate 3, as shown in Figure 3. In this case, the optical film 2 can be attached to the display device 1 via the adhesive layer 5. The adhesive layer 5 includes a material that does not easily affect the optical properties of the optical film 2, such as optical glue. Another layer may be placed between the light-transmitting substrate 3 and the anti-glare layer 4. 【0085】 In one embodiment, the optical film 2 may have an anti-reflective layer disposed on the surface 4a of the anti-glare layer 4 opposite to the light-transmitting substrate 3 side. In this embodiment, the surface of the anti-reflective layer opposite to the anti-glare layer 4 side is the surface 2a of the optical film 2. The anti-reflective layer prevents reflection of external light. The anti-reflective layer has a first structure, for example, consisting only of a single low refractive index layer. Alternatively, the anti-reflective layer has a second structure, which includes a laminated structure of a single low refractive index layer and a single high refractive index layer having a higher refractive index than the low refractive index layer. Alternatively, the anti-reflective layer has a third structure, which is a laminated structure of three or more layers, including low refractive index layers and high refractive index layers arranged alternately on top of each other. The low refractive index layer has a refractive index lower than that of the anti-glare layer 4, for example. The low refractive index layer may have antifouling properties. In this case, the low refractive index layer may contain antifouling agents such as silicone compounds or fluorine compounds. 【0086】 The method for forming the low refractive index layer and the high refractive index layer is not particularly limited, and examples include known wet methods or dry methods. When the anti-reflective layer has a first or second structure, for example, the wet method is preferable. When the anti-reflective layer has a third structure, for example, the dry method is preferable. 【0087】 The refractive index of the anti-reflective layer is not particularly limited. Furthermore, the thickness of the anti-reflective layer can be set within a range that ensures the anti-glare properties of the optical film 2. For example, the thickness of the anti-reflective layer can be set such that the spectral reflectance is lowest around 550 nm when the spectral reflectance spectrum of the optical film 2 is measured. 【0088】 When the anti-reflective layer has a first or second structure, for example, the refractive index of the low refractive index layer is a value in the range of 1.34 or higher. In this case, the refractive index of the low refractive index layer is preferably in the range of 1.34 to 1.45, more preferably in the range of 1.34 to 1.4, even more preferably in the range of 1.34 to 1.39, and even more preferably in the range of 1.34 to 1.38. For example, by setting the refractive index of the low refractive index layer not to be too high, the decrease in the anti-reflective properties of the anti-reflective layer can be suppressed. 【0089】 When the anti-reflective layer has a first structure or a second structure, the thickness of the low refractive index layer is preferably in the range of 50 nm to 300 nm, more preferably in the range of 60 nm to 150 nm, even more preferably in the range of 80 nm to 120 nm, and even more preferably in the range of 90 nm to 110 nm. 【0090】 For the composition of the low refractive index layer, refer to, for example, the compositions of the low refractive index layer described in Japanese Patent Publication No. 2001-100006, Japanese Patent Publication No. 2008-58723, and International Publication No. 2016 / 039125. The low refractive index layer is composed of, for example, a composition containing a low refractive index resin. Alternatively, the low refractive index layer may be composed of, for example, a cured product of a composition containing a curable resin and a fluorine-containing compound or a low refractive index inorganic filler. 【0091】 Examples of low refractive index resins include fluororesins such as methylpentene resin, diethylene glycol bis(allyl carbonate) resin, polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF). Examples of curable resins include fluorine-free photocurable resins used as materials for the anti-glare layer 4. Examples of fluorine-containing compounds include fluorine-containing photocurable resins used as materials for the anti-glare layer 4. 【0092】 The proportion of fluorine-containing compounds in the composition constituting the low refractive index layer is, for example, a value in the range of 1% by mass or more relative to the entire composition. This proportion may also be, for example, a value in the range of 5% by mass or more and 90% by mass or less. Examples of low refractive index inorganic fillers include the filler described in Japanese Patent Publication No. 2001-100006. As such inorganic fillers, low refractive index fillers such as silica and magnesium fluoride are preferred, and silica is particularly preferred. Examples of silica include hollow silica described in Japanese Patent Publication No. 2001-233611 or Japanese Patent Publication No. 2003-192994, etc. Among these, hollow silica is preferred, for example, because it can suppress the increase of haze and improve transparency. 【0093】 Furthermore, the number-average particle size (number-average primary particle size) of inorganic fillers (especially hollow silica) measured by electron microscopy is, for example, a value in the range of 100 nm or less. As an example, a value in the range of 80 nm or less is desirable. As another example, a value in the range of 10 nm to 80 nm is desirable, and a value in the range of 20 nm to 70 nm is more desirable. 【0094】 The proportion of low refractive index inorganic filler (particularly hollow silica) in the composition constituting the low refractive index layer is, for example, in the range of 1% by mass or more relative to the whole composition. This proportion may also be in the range of 5% by mass or more and 90% by mass or less. Furthermore, the low refractive index inorganic filler may be surface-modified with a coupling agent (titanium coupling agent, silane coupling agent). In addition, the composition containing the low refractive index inorganic filler may contain other inorganic fillers to improve the strength of the coating film. 【0095】 Furthermore, the composition of the low refractive index layer may include a curing agent and known additives used as materials for the anti-glare layer 4. Also, the anti-glare layer of this embodiment may be formed by any of the formation methods. 【0096】 When the anti-reflective layer has a second structure, it is desirable that the high refractive index layer be positioned closer to the anti-glare layer 4 than, for example, the low refractive index layer. The refractive index of the high refractive index layer can be appropriately set within a range higher than the refractive index of the low refractive index layer. In this case, the refractive index of the high refractive index layer is, for example, a value in the range of 1.53 or higher. In this case, it is desirable that the refractive index of the high refractive index layer be, for example, a value in the range of 1.54 or higher, more preferably a value in the range of 1.55 or higher, and even more preferably a value in the range of 1.56 or higher. In this case, it is desirable that the refractive index of the high refractive index layer be, for example, a value in the range of 1.85 or lower, more preferably a value in the range of 1.80 or lower, and even more preferably a value in the range of 1.75 or lower. 【0097】 When the anti-reflective layer has a second structure, the thickness of the high refractive index layer is, for example, a value in the range of 200 nm or less. In this case, the thickness of the high refractive index layer is preferably in the range of 180 nm or less, and more preferably in the range of 150 nm or less. Also in this case, the thickness of the high refractive index layer is preferably in the range of 50 nm or more, and more preferably in the range of 70 nm or more. 【0098】 For the configuration of the high refractive index layer, for example, the configuration of the high refractive index layer described in Japanese Patent Publication No. 2016-097529 can be referenced. The high refractive index layer is composed of, for example, a composition containing a high refractive index resin. Alternatively, the high refractive index layer may be composed of, for example, a cured product of a composition containing inorganic fine particles. Examples of particle sizes for the inorganic fine particles include nanometer size. The number-average particle size (number-average primary particle size) of the inorganic fine particles is, for example, a value in the range of 1 nm to 100 nm. The number-average particle size of the inorganic fine particles is preferably in the range of 2 nm to 50 nm, more preferably in the range of 3 nm to 40 nm, and even more preferably in the range of 5 nm to 30 nm. The number-average particle size of the inorganic fine particles can be measured using a conventional method with a particle size analyzer. The number-average particle size of the inorganic fine particles can be measured, for example, using a particle size analyzer (Otsuka Electronics Co., Ltd.'s laser particle size analyzer "PAR-III") based on dynamic light scattering. 【0099】 The shape of inorganic particles is not particularly limited. Examples of inorganic particle shapes include spherical, ellipsoidal, polygonal (pyramidal, tetragonal, cuboidal, etc.), plate-like, rod-like, or amorphous. As for the shape of inorganic particles, an isotropic shape such as a nearly spherical shape is desirable because it can scatter light isotropically and improve visibility. 【0100】 Examples of inorganic compounds constituting inorganic nanoparticles include elemental metals and metal oxides. For example, metal oxides are preferable because they can increase the refractive index of the high refractive index layer 91. Examples of metal oxides include Group 4A metal oxides (e.g., titanium oxide, zirconium oxide), Group 5A metal oxides (e.g., vanadium oxide), Group 6A metal oxides (e.g., molybdenum oxide, tungsten oxide), Group 7A metal oxides (e.g., manganese oxide), Group 8 metal oxides (e.g., nickel oxide, iron oxide), Group 1B metal oxides (e.g., copper oxide), Group 2B metal oxides (e.g., zinc oxide), Group 3B metal oxides (e.g., aluminum oxide, indium oxide), Group 4B metal oxides (e.g., silicon oxide, tin oxide), and Group 5B metal oxides (e.g., antimony oxide). These metal oxides can be used individually or in combination of two or more. Among these metal oxides, for example, Group 4A metal oxides of the periodic table such as titanium dioxide and zirconium oxide are preferred because they can increase the refractive index of the high refractive index layer 91 with a small proportion and suppress the increase in haze even when the amount added increases, and zirconium oxide is particularly preferred. 【0101】 High refractive index resins include, for example, curable resins. Examples of curable resins include UV-curable resins. Preferred UV-curable resins include polyfunctional (meth)acrylates such as pentaerythritol tri(meth)acrylate and dipentaerythritol hexa(meth)acrylate. 【0102】 If the anti-reflective layer has a third structure, it is desirable that the third structure includes a low refractive index layer located on the outermost surface of the optical film 2. If the anti-reflective layer has a third structure, the thickness of each high refractive index layer is preferably in the range of 10 nm to 200 nm, and more preferably in the range of 20 nm to 70 nm. In this case, it is also desirable that the refractive index of each high refractive index layer 91 is preferably in the range of 2.00 to 2.60. 【0103】 Furthermore, if the anti-reflective layer has a third structure, the thickness of each low refractive index layer is preferably in the range of 5 nm to 200 nm, and more preferably in the range of 20 nm to 120 nm. In this case, the refractive index of each low refractive index layer is preferably in the range of 1.20 to 1.60. 【0104】 The anti-reflective layer is not limited to having any of the first to third structures. The anti-reflective layer may have a structure that includes another layer, for example, at least one intermediate refractive index layer having a refractive index higher than the low refractive index layer and lower than the high refractive index layer. In this case, the intermediate refractive index layer may be combined with, for example, at least one of the low refractive index layer or the high refractive index layer. 【0105】 [Display device] As shown in Figure 3, the display device 1 includes an optical film 2. In this example, the display device 1 includes a display element 16 and an optical film 2 with an adhesive layer 5. The optical film 2 is attached to the display surface 16a of the display element 16. The types of display elements 16 are not limited. For example, the display elements 16 include displays such as liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs), inorganic light-emitting diodes (ELs), and plasma display panels (PDPs). Examples of display devices 1 include personal computers (PCs), monitors, televisions, and smartphones. 【0106】 [Optical components] As shown in Figure 4, the optical component 10 includes an optical film 2. In this example, the optical component 10 includes the optical film 2 and a polarizing plate 6 placed on top of the optical film 2. The polarizing plate 6 polarizes incident light from the outside. Furthermore, as shown in Figure 5, the polarizing plate 6 may have a phase difference film 8 and a plate-shaped polarizing element 7 superimposed on the phase difference film 8. Examples of materials for the polarizing element 7 include polyvinyl alcohol (PVA) dyed and stretched with iodine, polyvinyl formal, polyvinyl acetal, and ethylene-vinyl acetate copolymer saponified products. Examples of materials for the phase difference film 8 include triacetylcellulose and cycloolefin polymers. According to this embodiment, incident light on the phase difference film 8 is incident on the polarizing element 7, polarized, and then passes through the optical film 2 in the direction from the light-transmitting substrate 3 to the anti-glare layer 4. 【0107】 The configuration of the polarizing plate 6 is not limited, and known configurations can be adopted. For example, the polarizing plate 6 may include a protective film containing polyethylene terephthalate (PET) or the like. 【0108】 As shown in Figure 6, in one embodiment, the display device 1 comprises a light source 17, a polarizing plate 18 arranged on the optical path of the light source 17, a panel-shaped display element 16 placed on top of the polarizing plate 18 with its surface opposite to the image display side facing the polarizing plate 18, and an optical member 10 arranged on the image display side of the display element 16. As an example, the display element 16 includes an LCD. The light source 17 is a backlight. The surface 4a of the anti-glare layer 4 in the optical member 10 is located at the uppermost position in the thickness direction of the display device 1. The polarizing plate 18 is a polarizing plate separate from the polarizing plate 6 provided in the optical member 10. 【0109】 When the display device 1 is driven, the light emitted from the light source 17 is polarized by the polarizing plate 18 and then sequentially incident into the interior of the display element 16 and the optical member 10. Consequently, the image on the display element 16 is made visible by the light emitted to the outside from the surface 4a of the anti-glare layer 4 of the optical member 10. 【0110】 A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of this disclosure are disclosed below. [1] An optical film having an uneven surface on one of its surfaces, An optical film wherein the root mean square slope RΔq of the surface having an uneven shape is 0.015 or less, when the cutoff value λc is 0.08 mm in accordance with JIS B0601:2013. [2] The optical film according to [1], wherein the ratio of the sum of reflected light intensities of -5° to -2° and 2° to 5°, to the sum of reflected light intensities of -5° to -2° and 2° to 5°, as measured by a goniotphotometer, on the surface having the uneven shape, is 8% or less. [3] The optical film according to [1] or [2], wherein the surface of the side having the uneven shape has a 10-point average roughness RzJIS of 0.2 μm or more when the cutoff value λc is 0.8 mm in accordance with JIS B0601:2013. [4] An optical film as described in any of [1] to [3], wherein the haze is 10% or less. [5] An optical film according to any one of [1] to [4], comprising a light-transmitting substrate and an anti-glare layer. [6] The optical film according to [5], further comprising an anti-reflective layer on the anti-glare layer. A display device comprising an optical film as described in any of [7][1] to [6]. An optical component comprising an optical film as described in any of [8], [1] to [6]. Each configuration and its combination in each embodiment is an example, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of this disclosure. This disclosure is not limited by the embodiments. [Examples] 【0111】 The present disclosure will be further illustrated by the following examples, but these examples will not limit the interpretation of the present disclosure. 【0112】 [Example 1] The following anti-glare coating solution 1 was cast onto a substrate (a 60 μm thick triacetylcellulose resin film, "Fujitac TG60UL" manufactured by Fujifilm Corporation) using a wire bar (#12), and then left in a 100°C oven for 1 minute to evaporate the solvent. Then, ultraviolet light was irradiated for approximately 5 seconds using a high-pressure mercury lamp (cumulative light intensity approximately 200 mJ / cm²). 2 Irradiation (the same applies below) was used to form an anti-glare layer approximately 5 μm thick. Next, the low refractive index layer coating solution 1 described below was cast onto the anti-glare layer using a wire bar (#4), and then left in an 80°C oven for 1 minute to evaporate the solvent. Then, under a nitrogen atmosphere with an oxygen concentration of 200 ppm or less, ultraviolet light was irradiated for approximately 5 seconds using a high-pressure mercury lamp (cumulative light intensity approximately 200 mJ / cm²). 2 Irradiation (the same applies hereafter) formed a low refractive index layer with a thickness of approximately 0.1 μm, and the optical film of Example 1 was obtained. 【0113】 {Anti-glare coating solution 1} • Urethane-modified copolymer polyester resin 26 parts (Toyobo MC Co., Ltd. "UR-3200", solid content concentration 30% by mass) • Acrylic polymer 29.5 parts (Taisei Fine Chemical Co., Ltd. "8KX-078", solid content concentration 40% by mass) • Dipentaerythritol hexaacrylate 80.7 parts (Daicel Ornex Co., Ltd.'s "DPHA") • Photopolymerization initiator A (2 parts) (“Omnirad184” made by IGM Resins BV) • Photopolymerization initiator B (2 parts) (Tronly "TR-NPI-20400") • Fluorine-based compound A having polymerizable groups (1 part) (Neos Co., Ltd. "Futergent 602A", solid content concentration 50% by mass) • Solvent (methyl ethyl ketone) 57.2 parts • Solvent (methyl isobutyl ketone) 155 parts • Solvent (cyclohexanone) 11.5 parts 【0114】 {Low refractive index layer coating solution 1} • Hollow silica-dispersed acrylic hard coating liquid: 100 units (P-5063 manufactured by JGC Catalysts & Chemicals Co., Ltd., solid content concentration 3% by mass) • Fluorine-based compound B having polymerizable groups: 0.67 parts (Shin-Etsu Chemical Co., Ltd. "KY-1203", solid content concentration 20% by mass) • Solvent (methyl isobutyl ketone) 15.9 parts • Solvent (isopropyl alcohol) 4.0 parts 【0115】 [Example 2] The optical film of Example 2 was obtained under the same manufacturing conditions as in Example 1, except that the anti-glare coating solution 1 of Example 1 was modified to use 27.7 parts of urethane-modified copolymer polyester resin, 33.6 parts of acrylic polymer, and 78.6 parts of dipentaerythritol hexaacrylate in anti-glare coating solution 2. 【0116】 [Example 3] The following anti-glare coating solution 3 was cast onto a substrate (a 60 μm thick triacetylcellulose resin film, "Fujitac TG60UL" manufactured by Fujifilm Corporation) using a wire bar (#12), and then left in an 80°C oven for 1 minute to evaporate the solvent. Then, ultraviolet light was irradiated from a high-pressure mercury lamp for about 5 seconds to form an anti-glare layer with a thickness of about 5 μm, obtaining the optical film of Example 3. 【0117】 {Anti-glare coating solution 3} Pentaerythritol (tri / tetra)acrylate 20 parts (PETRA manufactured by Daicel Ornex Co., Ltd.) • Dipentaerythritol hexaacrylate 12 parts (Daicel Ornex Co., Ltd.'s "DPHA") • Photopolymerization initiator A (2 parts) (“Omnirad184” made by IGM Resins BV) • Photopolymerization initiator C 2 parts (“Omnirad127” made by IGM Resins BV) • Cross-linked acrylic monodisperse fine particles A 2.5 parts ("Techpolymer SSX-105" manufactured by Sekisui Plastics Co., Ltd., average particle size 5 μm) • Cross-linked acrylic monodisperse fine particles B 0.85 parts ("Techpolymer SSX-103" manufactured by Sekisui Plastics Co., Ltd., average particle size 3μm) • Fluorine-based compound A having polymerizable groups: 0.072 parts (Neos Co., Ltd. "Futergent 602A", solid content concentration 50% by mass) • Solvent (toluene) 50 copies • Solvent (cyclohexanone) 14 parts 【0118】 [Example 4] On a substrate (a 60 μm thick triacetylcellulose resin film, "Fujitac TG60UL" manufactured by Fujifilm Corporation), an anti-glare layer coating solution 4, which was modified by changing the anti-glare layer coating solution 3 to contain 5 parts of crosslinked acrylic monodisperse fine particles A and 1.7 parts of crosslinked acrylic monodisperse fine particles B, was cast using a wire bar (#10), and then left in an 80°C oven for 1 minute to evaporate the solvent. Then, ultraviolet light was irradiated from a high-pressure mercury lamp for about 5 seconds to form an anti-glare layer with a thickness of about 4 μm. Next, the low refractive index layer coating solution 1 was cast onto the anti-glare layer using a wire bar (#4), and then left in an 80°C oven for 1 minute to evaporate the solvent. Then, ultraviolet light was irradiated from a high-pressure mercury lamp for about 5 seconds under a nitrogen atmosphere with an oxygen concentration of 200 ppm or less to form a low refractive index layer with a thickness of about 0.1 μm, obtaining the optical film of Example 4. 【0119】 [Example 5] An optical film of Example 5 was obtained under the same manufacturing conditions as in Example 3, except that an anti-glare layer coating solution 5 was used, in which the anti-glare layer coating solution 3 of Example 3 was modified by changing the amount of cross-linked acrylic monodisperse fine particles A to 0.85 parts and the amount of cross-linked acrylic monodisperse fine particles B to 2.5 parts, and an anti-glare layer with a thickness of approximately 4 μm was formed using a wire bar (#10). 【0120】 [Comparative Example 1] The optical film of Comparative Example 1 was obtained under the same manufacturing conditions as in Example 3, except that anti-glare coating solution 4 was used. 【0121】 [Comparative Example 2] The optical film of Comparative Example 2 was obtained under the same manufacturing conditions as in Example 3, except that an anti-glare layer with a thickness of approximately 4 μm was formed using a wire bar (#10). 【0122】 [Comparative Example 3] The optical film of Comparative Example 3 was obtained under the same manufacturing conditions as in Example 3, except that an anti-glare layer with a thickness of approximately 3 μm was formed using a wire bar (#8). 【0123】 Furthermore, each optical film in the examples and comparative examples was evaluated by measuring the following items. 【0124】 [Root Mean Square Slope RΔq] In accordance with JIS B 0601:2013, measurements were taken using a contact-type surface roughness meter (Surfcom 1400G, manufactured by Tokyo Seimitsu Co., Ltd.) under the following conditions. • Cutoff wavelength λc = 0.08 mm • Cutoff ratio λc / λs = 30 • Stylus: Diamond, conical shape, tip radius 2 μm, apex angle 60° • Stylus feed rate = 0.1 mm / sec • Evaluation length: 5 times the cutoff value λc • Reserve length: (cutoff value λc) × 2 • Cutoff filter type: Gaussian 【0125】 [The ratio of the sum of reflected light intensities for angles of incidence of -5° to -2° and 2° to 5° to the sum of reflected light intensities for angles of incidence of -5° to 5°] The ratio of the sum of reflected light intensities between -5° and -2°, and between 2° and 5° to the sum of reflected light intensities between -5° and 5° of the incident angle difference was measured using a goniophotometer (automatic variable-angle photometer, "GP-200 model," manufactured by Murakami Color Technology Laboratory Co., Ltd.). An evaluation sample was prepared by attaching the back surface of optical film 2 (the side without a surface unevenness, the side opposite to the observer) to a flat black acrylic plate without unevenness or warping using a transparent adhesive. Next, the evaluation sample was placed in the measuring device, and a light beam was incident on the anti-glare film side of the evaluation sample at an angle of 5 degrees from the normal to the surface. The 5-degree angle, which is the specular reflection direction of the incident light, was defined as the specular reflection direction. The reflected light intensity was measured by scanning the light receiver at 0.1-degree intervals within the range of -5° to +5° relative to the specular reflection direction of the light beam incident on the anti-glare film surface of the evaluation sample. 【0126】 [10-point average roughness (RzJIS)] In accordance with JIS B 0601:2001, measurements were taken using a contact-type surface roughness meter (Surfcom 1400G, manufactured by Tokyo Seimitsu Co., Ltd.) under the following conditions. • Cutoff wavelength λc = 0.8 mm • Cutoff ratio λc / λs = 300 • Stylus: Diamond, conical shape, tip radius 2 μm, apex angle 60° • Stylus feed rate = 0.1 mm / sec • Evaluation length: 5 times the cutoff value λc • Reserve length: (cutoff value λc) × 2 • Cutoff filter type: Gaussian 【0127】 [Haze and total light transmittance] The haze was measured using a haze meter (HM-150L2, manufactured by Murakami Color Technology Laboratory Co., Ltd.) in accordance with JIS K7136. The haze was measured with the surface having an uneven structure facing the light receiver. 【0128】 [Anti-glare] An evaluation sample, made by bonding a commercially available black acrylic plate to the light-transmitting substrate side of the fabricated optical film using optical adhesive, was placed on a horizontal surface. A fluorescent lamp was positioned 3 m vertically from the evaluation sample, and the reflected image when the fluorescent lamp was projected onto the sample was visually observed and evaluated according to the following criteria. ◎: The shape of the fluorescent light is completely invisible. ○: The outline of the fluorescent light is blurred. △: The outline of the fluorescent light can be recognized. 【0129】 [White cast] An evaluation sample, created by bonding a commercially available black acrylic plate to the light-transmitting substrate side of the fabricated optical film using optical adhesive, was placed on a horizontal surface. A fluorescent lamp was positioned 3m vertically from the evaluation sample to reflect the light, and the sample was visually inspected from various angles and evaluated according to the following criteria. ◎: The whitish appearance of the surface is not noticeable, and the black appears very deep. ○: The surface appears slightly whitish. Black appears more defined. △: The surface appears slightly whitish. The black appears somewhat dull. ×: The surface appears white. Black appears dull. 【0130】 The measurement results for each of the above items are shown in Table 1. 【0131】 [Table 1] 【0132】 As shown in Table 1, the optical films of Examples 1 to 5 were shown to have good anti-glare properties and suppress the occurrence of white floating. In other words, by setting the type of phase separation material to be combined and the particle size and amount of fine particles contained in the anti-glare layer as in Examples 1 to 5, the root mean square slope RΔq, when the cutoff value λc is set to 0.08 mm in accordance with JIS B0601:2013, becomes 0.015 or less, resulting in good anti-glare properties and suppression of white floating. The reason why white floating was suppressed is thought to be that the inclination angle of the convex parts of the uneven shape became smaller, suppressing scattering at wide angles. 【0133】 On the other hand, although the optical films of Comparative Examples 1 to 3 had a 10-point average roughness RzJIS above a certain level and a haze below a certain level, their root mean square slope RΔq was above a certain level, and the occurrence of white floating was not suppressed. 【0134】 The present invention is not limited to the embodiments described above, and its configuration or methods may be changed, added, or deleted without departing from the spirit of the invention. [Explanation of Symbols] 【0135】 1 Display device 2 Optical film 2a Surface of the optical film 3 Light-transparent base material 4 Anti-glare layer 4a Surface of the anti-glare layer 5 Adhesive layer 6. Polarizing plate 7 Polarizing elements 8 Phase difference film 10 Optical components 16 Display Elements 16a Display side 17 Light source 18 Polarizing plate

Claims

[Claim 1] An optical film having an uneven surface on one of its surfaces, An optical film wherein the root mean square slope RΔq of the surface having an uneven shape is 0.015 or less, when the cutoff value λc is 0.08 mm in accordance with JIS B0601:2013. [Claim 2] The optical film according to claim 1, wherein the ratio of the sum of reflected light intensities between -5° and -2° and 2° and 5° to the sum of reflected light intensities between -5° and 5° in goniophotometer measurement, to the sum of reflected light intensities between -5° and 5° in goniophotometer measurement, is 8% or less on the surface having the uneven shape. [Claim 3] The optical film according to claim 1 or 2, wherein the surface of the side having the uneven shape has a 10-point average roughness RzJIS of 0.2 μm or more when the cutoff value λc is 0.8 mm in accordance with JIS B0601:2013. [Claim 4] The optical film according to claim 1 or 2, wherein the haze is 10% or less. [Claim 5] The optical film according to claim 1 or 2, comprising a light-transmitting substrate and an anti-glare layer. [Claim 6] The optical film according to claim 5, further comprising an anti-reflective layer on the anti-glare layer. [Claim 7] A display device comprising the optical film according to claim 1 or 2. [Claim 8] An optical member comprising the optical film described in claim 1 or 2.

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