Optical film

Abstract

Provided is an optical film having good antiglare properties and reduced glare.　The present invention provides an optical film having an uneven shape on one surface, and the number of protrusions having a height of 0.1 μm or more and a longest diameter of 20-100 μm in a short wavelength-side component when a cut-off value λc of the surface of the optical film on the uneven shape side is 0.08 mm is 100 or less per 1 mm2.

Description

Optical film 【0001】 This invention relates to an optical film. 【0002】 In high-definition image display devices such as LCDs and OLED displays, optical films such as anti-glare films are used to prevent reflection of ambient light onto the display surface. Anti-glare properties can be achieved by creating an uneven surface on the optical film to scatter and reflect ambient light. However, while attaching such an optical film to the display surface prevents reflection of ambient light onto the display surface, it may also degrade the display performance of the display surface through the optical film. 【0003】 In particular, when attached to a high-definition image display device, the uneven shape can cause glare and reduced visibility due to the refraction of light from the display surface passing through the optical film, or the lens effect causing the pixels of the display device to appear magnified. 【0004】 Japanese Patent Publication No. 2009-109702 【0005】 The object of this disclosure is to provide an optical film having good anti-glare properties and suppressed glare. 【0006】 This disclosure includes the following embodiments: [1] An optical film having an uneven surface on one of its surfaces, wherein the number of protrusions on the surface of the optical film having the uneven surface, in the short-wavelength component when the cutoff value λc is 0.08 mm, is 1 mm² or more in height and 20 μm or more in longest diameter and 100 μm or less. ２ Optical film, with fewer than 100 pieces per unit. 【0007】 According to this disclosure, it is possible to provide an optical film having good anti-glare properties and suppressed glare. 【0008】 This is a cross-sectional view of an optical film according to one embodiment of the present disclosure. This is a cross-sectional view of a display device according to one embodiment of the present disclosure. This is a cross-sectional view of a display device according to one embodiment of the present disclosure. This is a cross-sectional view of an optical member according to one embodiment of the present disclosure. This is a diagram showing an example of the schematic configuration of a glare evaluation device. This is a cross-sectional view of a display device according to one embodiment of the present disclosure. 【0009】 An embodiment of the present invention will be described below with reference to the accompanying drawings. The embodiment described below is illustrative and not intended to be 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 to 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 shape. The uneven shape preferably covers at least 90% of the surface of the optical film 2 that has the uneven shape, 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 a plurality of 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 the outside. 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 has a surface 2a on which, when the cutoff value λc is 0.08 mm, the number of protrusions on the short-wavelength side component with a height of 0.1 μm or more and a longest diameter of 20 μm or more and 100 μm or less (hereinafter also referred to as "spike-shaped protrusions") is 1 mm. ２ It is adjusted so that there are 100 or fewer per unit. In one embodiment, the number of spike-shaped protrusions is 1 mm ２ It is preferable that the number is adjusted to be 30 or less per unit, and 1 mm ２ It is more preferable that the number be adjusted to 10 or less per unit, and 1 mm ２ It is even more preferable that the number of spike-like protrusions be adjusted to three or fewer per 1 mm. ２ By adjusting the number of spike-like protrusions to be 100 or less per pixel, the number of protrusions that interfere with the pixels of the display device is reduced, and it is presumed that the glare of the optical film 2 is suppressed. The number of spike-like protrusions can be measured using a surface and layer cross-sectional shape measurement system (for example, "VertScan" manufactured by Ryoka Systems Co., Ltd.), by binarizing the surface height data of each pixel (640 x 480 = 307,200 pixels) using a threshold, labeling the areas adjacent to the binarized pixels, and calculating numerical values ​​such as the longest diameter and area for each labeled area. The number of spike-like protrusions can be adjusted, for example, by adjusting the type of phase separation material used, the drying conditions of the solvent, the particle size and amount of fine particles contained in the anti-glare layer, and the thickness of the anti-glare layer. 【0013】 In one embodiment, it is preferable that the optical film 2 is adjusted to a value within the range of 10 or less when it is mounted on the display surface 16a. Therefore, compared to designing based on a value indicating the degree of glare based on a subjective evaluation, for example, it is possible to stably suppress the glare to a desired range. It is more preferable that the glare value is adjusted to 8 or less, and even more preferable that it is adjusted to 6 or less. If the glare value is 10 or less, it can be evaluated that the glare is suppressed. The glare value is defined based on the value of the standard deviation of the luminance distribution of the display surface 16a when the optical film 2 is mounted on the display surface 16a. The method for measuring the glare value using the glare inspection machine 20 is described below. 【0014】 Figure 6 shows a schematic diagram of the glare inspection machine 20. The glare inspection machine 20 is a device for evaluating the glare of the display surface 16a of a display device 1 which has a film such as an optical film 2 attached to its surface, and comprises a housing 21, an imaging device 22, a holding unit 23, a stand for the imaging device 24, a stand for the display device 25, and an image processing device 27. An example of a commercially available glare inspection machine 20 is the "Film Glare Inspection Machine" manufactured by Komatsu NTC Co., Ltd. 【0015】 The housing 21 has a darkroom for capturing images of the display surface 16a by the imaging device 22. The housing 21 houses the imaging device 22, the holding unit 23, the mounting base 24 for the imaging device, the mounting base 25 for the display device, and the display device 1 to be evaluated. 【0016】 The imaging device 22 is, for example, an area camera having a lens 28 and an image sensor, and captures images displayed on the display surface 16a. The imaging device 22 is connected to the image processing device 27 and is held in the holding unit 23 so that the lens 28 and the display surface 16a face each other. The image data captured by the imaging device 22 is transmitted to the image processing device 27. 【0017】The holding portion 23 extends vertically and holds the imaging device 22 while being fixed to the mounting base 24 for the imaging device at its lower end. The holding portion 23 holds the imaging device 22 so that the relative distance between the display surface 16a and the lens 28 can be changed by moving the imaging device 22 relative to the display device 1 in a vertical direction. 【0018】 The display device 1 is placed on the upper surface of the display device stand 25 with the display surface 16a, on which the film is mounted, facing the imaging device 22. The display device stand 25 supports the display surface 16a on which the film is mounted so that its surface faces the imaging device 22 and is on a horizontal plane, and moves the display device 1 relative to the imaging device 22 in a vertical direction. 【0019】 In the glare inspection machine 20, the relative distance between the imaging device 22 and the display surface 16a is adjusted to control the pixel size of the image displayed on the display surface 16a, which is captured for each unit pixel (e.g., 1 pixel) of the image sensor of the imaging device 22. 【0020】 The image processing device 27 performs data processing on the image data captured by the imaging device 22. Specifically, the image processing device 27 calculates the standard deviation of the brightness of the display surface 16a from the image data captured by the imaging device 22. 【0021】 The image processing apparatus 27 of this embodiment includes an input unit that receives image data captured by the imaging device 22, an image processing unit that processes the input image data, and an output unit that outputs the results processed by the image processing unit to a display device or printing device, etc. 【0022】When the image captured by the imaging device 22 captures an image displayed on the display surface 16a, the pixel size of the image captured per unit pixel (e.g., 1 pixel) of the image sensor can be adjusted by changing the relative distance between the imaging device 22 and the display surface 16a, or, if the lens 28 of the imaging device 22 is a zoom lens, by changing the focal length of the imaging device 22. The F-number of the lens 28 and the shutter speed (exposure time) of the imaging device 22 can be set as appropriate. From the viewpoint of reducing the inclusion of periodic noise in the image data caused by the structure of the display surface 16a (e.g., pixels and pixel arrangement) during shooting, the F-number of the lens 28 is preferably in the range of F4 to F8 (for example, any of F4, F6, or F8). Of these, F8 is the most preferred F-number for the lens 28. The shutter speed of the imaging device 22 is preferably in the range where an appropriate amount of light can be obtained for glare inspection (for example, in the range of 0.01S to 0.1S). The shooting conditions can be set to, for example, the following. Lens 28 F-number: F8 Lens focal length: 12mm Y / X range: A value in the range of 1.65 or more and 1.75 or less, where X is the pixel size of the display (μm). Y is the shooting pitch of the pixels of the image sensor of the imaging device 22 (μm). In this document, a pixel refers to a collection of three pixels of RGB, which are the units for displaying color when the display uses the three primary colors R (Red), G (Green), and B (Blue). Furthermore, the shooting pitch refers to the average value {(A1 + A2) / 2} of the value A1 (A1 = Ll / N1), which is calculated by dividing the vertical length L1 of the image captured by the image sensor of the imaging device 22 by the number of vertical pixels N1 of the image sensor of the imaging device 22, and the value A2 (A2 = L2 / N2), which is calculated by dividing the horizontal length L2 of the image captured by the image sensor of the imaging device 22 by the number of horizontal pixels N2 of the image sensor of the imaging device 22. 【0023】 • Glare Evaluation Method A glare evaluation method using the glare inspection machine 20 will be described. In this glare evaluation method, for the convenience of evaluation, the display element 16 with the optical film 2 attached to its surface is pre-lit and displayed with uniform illumination of one color (green as an example). 【0024】 First, the size of the pixels of the display element 16, which is fitted with an optical film 2 that is imaged per unit pixel of the image sensor of the imaging device 22, is adjusted to a predetermined value (adjustment step). 【0025】 In the adjustment step, the relative distance between the imaging device 22 and the display element 16 fitted with the optical film 2 is adjusted according to the number of effective pixels of the image sensor of the imaging device 22, so that in the image data captured by the imaging device 22, there are no bright lines of pixels in the image displayed on the display element 16 fitted with the optical film 2, or if there are bright lines, they do not affect the evaluation of glare. 【0026】 Furthermore, it is desirable that the relative distance between the imaging device 22 and the display device 1 be set considering the actual usage of the display device 1 (for example, the relative distance between the user's eye and the display element 16). 【0027】 After performing the adjustment step, a measurement area is set to evaluate the glare of the display element 16 with the optical film 2 attached (setting step). In the setting step, the measurement area can be appropriately set according to, for example, the size of the display element 16. 【0028】 After performing the adjustment step, the measurement area of ​​the display element 16 with the optical film 2 attached is imaged by the imaging device 22 (imaging step). At this time, as an example, at least one of the exposure time of the imaging device 22 or the brightness of all pixels of the display element 16 is adjusted so that image data of a grayscale image with 8-bit gradation display and an average brightness of 170 gradations is obtained. The image data captured in the imaging step is input to the image processing device 27. 【0029】After the imaging step, the image processing device 27 calculates the luminance variation in the image of the measurement area of ​​the display element 16 fitted with the optical film 2 from the image data (calculation step). In this calculation step, the luminance variation can be quantified by calculating the standard deviation of the luminance distribution. Here, the degree of glare of the display element 16 fitted with the optical film 2 increases as the luminance variation of the display element 16 fitted with the optical film 2 increases. Based on this, the smaller the value of the standard deviation of the luminance distribution, the smaller the glare can be evaluated quantitatively and objectively. Furthermore, in the adjustment step, the emission lines of the display element 16 fitted with the optical film 2 are adjusted to the extent that they do not affect the evaluation of glare, so that luminance unevenness due to emission lines is suppressed and accurate glare evaluation can be performed. 【0030】 By following the steps described above, the standard deviation of the brightness distribution of the display element 16 with the optical film 2 attached to its surface can be determined, and the glare can be evaluated based on the magnitude of this value. 【0031】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 cone with tip radius 2 μm and 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 irregularities are 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 irregularities with varying heights. In addition, when surface irregularities are formed using 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 causing aggregation, thereby forming a surface with varying heights on the anti-glare layer. In molding using a mold, the 10-point average roughness RzJIS can be adjusted by adjusting the irregularities of the mold. 【0032】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 of JIS K7136:2000. In the case of surface formation using phase separation, the 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 unevenness 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, the haze tends to increase by increasing the particle size of the fine particles, decreasing the film thickness, causing aggregation to form a structure with height differences on the surface of 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, the haze can be adjusted by adjusting the unevenness of the mold. 【0033】Hereinafter, specific examples of the light-transmissive substrate 3 and the antiglare layer 4 will be described. (Light-transmissive substrate) As the material of the light-transmissive substrate 3, for example, glass, ceramics, and resin can be exemplified. As the resin, the same resin as the material of the antiglare layer 4 can be used. Preferred materials for the light-transmissive substrate 3 include transparent polymers, such as cellulose derivatives (such as cellulose acetate like cellulose triacetate (TAC), cellulose diacetate, etc.), polyester resins (such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyarylate resins, etc.), polysulfone resins (such as polysulfone, polyethersulfone (PES), etc.), polyether ketone resins (such as polyether ketone (PEK), polyether ether ketone (PEEK), etc.), polycarbonate resins (PC), polyolefin resins (such as polyethylene, polypropylene, etc.), cyclic polyolefin resins (films such as "ARTON" (registered trademark) manufactured by JSR Corporation, "ZEONEX" (registered trademark) manufactured by Nippon Zeon Co., Ltd., etc.), halogen-containing resins (such as polyvinylidene chloride, etc.), (meth)acrylic resins, styrene resins (such as polystyrene, etc.), vinyl acetate or vinyl alcohol resins (such as polyvinyl alcohol, etc.). 【0034】 The light-transmissive substrate 3 may be uniaxially or biaxially stretched, but is preferably optically isotropic and has a low refractive index. Examples of the optically isotropic light-transmissive substrate 3 include an unstretched film. 【0035】 The thickness dimension of the light-transmissive substrate 3 can be appropriately set. For example, it is preferably a value in the range of 5 μm or more and 2000 μm or less, more preferably in the range of 15 μm or more and 1000 μm or less, and even more preferably a value in the range of 20 μm or more and 500 μm or less. 【0036】 (Antiglare layer) The antiglare layer 4 has a predetermined uneven shape. The uneven shape of the antiglare layer can be formed, for example, by (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, (E) an etching process, etc. 【0037】 - First Embodiment The antiglare layer 4 according to the first embodiment of the present disclosure has a phase-separated structure of a plurality of resin components. As an example, the antiglare layer 4 has a surface 4a on which a plurality of convex portions are dispersedly arranged. Thereby, the surface 4a of the antiglare layer 4 in the present embodiment has an island-in-sea structure formed by the plurality of convex portions and the concave portions therebetween. The antiglare layer 4 exhibits antiglare properties due to the uneven shape formed by the plurality of convex portions and the concave portions therebetween. By providing such an antiglare layer 4, the optical film 2 has an excellent balance between haze and transmission image sharpness (imageability). Note that the surface 4a of the antiglare layer 4 may have a co-continuous phase structure in which a plurality of convex portions are arranged in a dense state. 【0038】 Also, in the optical film 2, light from the display surface 16a transmitted through the antiglare layer 4 is prevented from being refracted by the unevenness on the surface of the antiglare layer 4 or from making the pixels of the display surface 16a appear enlarged due to the lens effect caused by the uneven shape of the surface 4a of the antiglare layer 4, and the glare on the display surface 16a is suppressed. Thereby, even when the optical film 2 is attached to the display surface 16a having high-definition pixels, it is possible to highly suppress the glare on the display surface 16a while ensuring antiglare properties, and it is also possible to suppress blurring of characters and images. 【0039】 As will be described later, the phase-separated structure of the antiglare layer 4 according to the first embodiment is formed by spinodal decomposition (wet spinodal decomposition) from the liquid phase using a solution that serves as a raw material for the antiglare layer 4. For details of the antiglare layer 4 according to the present embodiment, for example, reference can be made to the description in Japanese Patent Application Laid-Open No. 2014-085371. 【0040】The plurality of resin components included in the antiglare layer 4 according to this embodiment may be those capable of phase separation. Examples of the polymer included in the antiglare layer 4 include thermoplastic resins. Examples of thermoplastic resins include styrene resins, (meth)acrylic resins, vinyl organic acid 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 (such as polyethersulfone and polysulfone), polyphenylene ether resins (such as polymers of 2,6-xylenol), cellulose derivatives (such as cellulose esters, cellulose carbamates, cellulose ethers, etc.), silicone resins (such as polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubber or elastomers (such as diene rubbers such as polybutadiene and polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic rubbers, urethane rubbers, silicone rubbers, etc.). These thermoplastic resins can be used alone or in combinations of two or more. 【0041】 Further, examples of the polymer also include those having a functional group involved in a curing reaction or a functional group that reacts with a curable compound. This polymer may have the functional group in the main chain or side chain. 【0042】 Examples of the functional group include condensable groups and reactive groups (for example, hydroxyl group, acid anhydride group, carboxyl group, amino group or imino group, epoxy group, glycidyl group, isocyanate group), polymerizable groups (for example, vinyl, propenyl, isopropenyl, butenyl, allyl group, etc. C ２－６ alkenyl group, ethynyl, propynyl, butynyl group, etc. C ２－６ alkynyl group, vinylidene group, etc. C ２－６ alkenylidene group, or a group having these polymerizable groups ((meth)acryloyl group, etc.)). Among these functional groups, polymerizable groups are desirable. 【0043】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. 【0044】 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. 【0045】 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. 【0046】 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. 【0047】 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. 【0048】 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. 【0049】 Examples of curable resin precursors include curable compounds that have functional groups that react to active energy rays (such as ultraviolet light or electron beams) or heat, and that harden or crosslink through these functional groups to form a resin (particularly a cured resin or crosslinked resin). 【0050】 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). 【0051】 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, the photocurable compound is preferably epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, silicone (meth)acrylate, or a polyfunctional monomer having at least two polymerizable unsaturated bonds. 【0052】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. 【0053】 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. 【0054】 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. 【0055】 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. 【0056】The anti-glare layer 4 may contain a matrix resin having a phase separation 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. 【0057】 Examples of organic microparticles include cross-linked acrylic particles and cross-linked styrene particles. Examples of inorganic microparticles include silica (SiO₂). ２ ), Zirconia (ZrO ２ ), Titania (TiO ２ Examples of fine particles of various metal oxides include indium tin oxide, tin oxide, indium oxide, germanium oxide, zinc oxide, and aluminum oxide. Examples of inorganic fine particles include metal fluoride particles, metal sulfide particles, metal nitride particles, and metal particles. The fine particles contained in the anti-glare layer 4 are preferably those with good transparency. For example, if the fine particles contain silica, it becomes easier to improve the hardness of the optical film 2. The refractive index difference between the fine particles contained 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. 【0058】 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. 【0059】 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. Also, for example, setting the average particle size of the fine particles to a value that is not too large makes it easier to suppress glare. 【0060】The thickness of the anti-glare layer 4 can be set as appropriate, but for example, it is a value in the range of 0.3 μm to 20 μm. Preferably, the thickness is a value in the range of 1 μm to 15 μm, and more preferably, a value in the range of 1 μm to 10 μm. For example, the thickness can usually be set to a value in the range of 2 μm to 10 μm (particularly a value in the range of 3 μm to 7 μm). 【0061】 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. 【0062】 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. 【0063】 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). 【0064】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.), and so on. The solvent may also be a mixed solvent. 【0065】 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. 【0066】 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. 【0067】 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. 【0068】In the forming process, the solution prepared in the preparation process is cast or coated onto the surface of a support (in this case, a light-transmitting substrate 3 as an example). Examples of conventional methods for casting or coating the solution include 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, silkscreen coater, etc. 【0069】 The solvent is removed from the solution cast or coated onto the surface of the support by evaporation during drying. This evaporation process concentrates the solution, causing phase separation of multiple resin components from the liquid phase through spinodal decomposition, thereby 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. 【0070】 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. 【0071】 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, the 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. 【0072】 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, perfectly spherical, disc-shaped, 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. 【0073】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. 【0074】 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. 【0075】 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. 【0076】 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. The optical film 2 is manufactured by going through the above steps. 【0077】 The basic method for forming the anti-glare layer is not 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 a formation method based on a fine particle dispersion method that forms the anti-glare layer 4 using a matrix resin 40 and a plurality of fine particles 41, as described in the following embodiments. The following describes other embodiments, focusing on the differences from the above embodiments. 【0078】・Second Embodiment The anti-glare layer 4 according to the second embodiment of this disclosure includes 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 outward from the surface of the matrix resin 40, thereby forming an uneven shape on the surface 4a of the anti-glare layer 4. 【0079】 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. 【0080】 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. 【0081】 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. 【0082】The fine particles 41 are set to have an average particle size in the range of 0.5 μm to 10 μm. The average particle size of the fine particles 41 is preferably 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. 【0083】 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 having different average particle sizes, it is desirable that the variation in particle size of each fine particle 41 be small. 【0084】 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. 【0085】The fine particles 41 dispersed in the matrix resin 40 may be 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. 【0086】 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). 【0087】 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. 【0088】 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. 【0089】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. 【0090】 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. 【0091】 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.). 【0092】Examples of thermosetting resins include phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, unsaturated polyester resins, polyurethane resins, epoxy resins, aminoalkyd 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. 【0093】 The method for manufacturing the optical film 2 equipped with the anti-glare layer 4 of 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. 【0094】 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. 【0095】 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. 【0096】 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, a wavelength range of 190 nm to 380 nm. 【0097】 Examples of electron sources include well-known electron beam accelerators. Specifically, examples include various types of electron beam accelerators such as Van de Graaff, Cockcroft-Walton, resonant transformer, insulated core transformer, linear, dynamitron, and high-frequency types. 【0098】 As the matrix resin 40 contained in the solution hardens, the positions of the fine particles 41 in the matrix resin 40 are fixed. As a result, multiple fine particles 41 are dispersed in the matrix resin 40, and an anti-glare layer 4 is formed with a structure in which an uneven shape is formed on the surface 4a by the fine particles 41. 【0099】 Other basic methods for forming anti-glare layers include a transfer formation method, which involves using a pre-prepared mold (master mold) to transfer the surface irregularities and form the anti-glare layer. In this case, the mold can be, for example, one on which a metal film has been formed by electrodeposition coating or the like on a previously manufactured optical film. Another basic method for forming anti-glare layers is to create irregularities on the surface of the anti-glare layer material by cutting it with a laser or the like. Yet another method is to create irregularities on the surface of the anti-glare layer material by polishing it using a shot blasting method with abrasive materials such as sand or beads. Finally, another method is to create irregularities on the surface of the anti-glare layer material by etching it. 【0100】 (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. 【0101】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. 【0102】 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 structure or a 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. 【0103】 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. 【0104】 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. 【0105】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. 【0106】 For the configuration of the low refractive index layer, refer to, for example, the configurations 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. 【0107】 Examples of low refractive index resins include methylpentene resin, diethylene glycol bis(allyl carbonate) resin, polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF), among other fluororesins. 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. 【0108】 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 Application 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 Application Publication No. 2001-233611 or Japanese Patent Application Publication No. 2003-192994, etc. Among these, hollow silica is preferred, for example, because it can suppress the rise of haze and improve transparency. 【0109】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. 【0110】 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. 【0111】 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. 【0112】 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. 【0113】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. 【0114】 For the configuration of the high refractive index layer, for example, the configuration of the high refractive index layer described in Japanese Patent Application 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. 【0115】 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. 【0116】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. 【0117】 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. 【0118】 If the anti-reflective layer has a third structure, it is desirable that the third structure includes a low refractive index layer disposed 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 preferable that the refractive index of each high refractive index layer 91 is preferably in the range of 2.00 to 2.60. 【0119】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. 【0120】 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. 【0121】 [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 element 16 includes displays such as liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs), inorganic light-emitting diodes (EL displays), and plasma display panels (PDPs). Examples of display devices 1 include personal computers (PCs), monitors, televisions, and smartphones. 【0122】[Optical Component] As shown in Figure 4, the optical component 10 includes an optical film 2. In this example, the optical component 10 includes an 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. Alternatively, as shown in Figure 5, the polarizing plate 6 may have a phase difference film 8 and a plate-shaped polarizing element 7 placed on top of 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, ethylene-vinyl acetate copolymer saponified material, etc. Examples of materials for the phase difference film 8 include triacetylcellulose and cycloolefin polymer. According to this embodiment, incident light on the phase difference film 8 is incident on the polarizing element 7 and polarized, and then passes through the optical film 2 in the direction from the light-transmitting substrate 3 to the anti-glare layer 4. 【0123】 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. 【0124】 As shown in Figure 7, the display device 1 in one embodiment includes 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 the 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 part 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. 【0125】 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. 【0126】A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure is disclosed below: [1] An optical film having an uneven surface on one of its surfaces, wherein the number of protrusions on the surface of the optical film having the uneven surface, in the short-wavelength component when the cutoff value λc is 0.08 mm, is 1 mm² or more, and the longest diameter is 20 μm or more and 100 μm or less. ２ [1] An optical film having 100 or fewer particles per surface. [2] The optical film according to [1], wherein the 10-point average roughness RzJIS of the surface having the uneven shape is 0.2 μm or more when the cutoff value λc is 0.8 mm in accordance with JIS B0601:2013. [3] The optical film according to [1] or [2], wherein the haze is 10% or less. [4] The optical film according to any one of [1] to [3], comprising a light-transmitting substrate and an anti-glare layer. [5] The optical film according to [4], further comprising an anti-reflective layer on the anti-glare layer. [6] A display device comprising the optical film according to any one of [1] to [5]. [7] An optical member comprising the optical film according to any one of [1] to [5]. Each configuration and combination thereof in each embodiment are examples, and additions, omissions, substitutions, and other changes to the configuration can be made as appropriate without departing from the spirit of this disclosure. This disclosure is not limited to embodiments. 【0127】 The present disclosure will be further illustrated by the following examples, but these examples will not limit the interpretation of the present disclosure. 【0128】 [Example 1] The following anti-glare coating liquid 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 about 5 seconds using a high-pressure mercury lamp (cumulative light intensity of about 200 mJ / cm²). ２(Irradiation, and so on) formed 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) was performed to form a low refractive index layer with a thickness of approximately 0.1 μm, thereby obtaining the optical film of Example 1. 【0129】 {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. "DPHA") ・Photopolymerization initiator A 2 parts (IGM Resins B.V. "Omnirad 184") ・Photopolymerization initiator B 2 parts (Tronly "TR-NPI-20400") ・Fluorine compound A with polymerizable group 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 【0130】 {Low refractive index layer coating solution 1} ・Hollow silica dispersed acrylic hard coat solution 100 parts (JGC Catalysts & Chemicals Co., Ltd. "P-5063", solid content concentration 3% by mass) ・Fluorine compound B with 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 【0131】 [Example 2] An optical film of Example 2 was obtained under the same manufacturing conditions as in Example 1, except that the anti-glare coating liquid 1 of Example 1 was modified to contain 27.7 parts of urethane-modified copolymer polyester resin, 33.6 parts of acrylic polymer, and 78.6 parts of dipentaerythritol hexaacrylate, in addition to the anti-glare coating liquid 2. 【0132】[Example 3] The following anti-glare coating liquid 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 about 5 μm thick, and the optical film of Example 3 was obtained. 【0133】 {Anti-glare coating solution 3} ・Pentaerythritol (tri / tetra)acrylate 20 parts (PETRA, manufactured by Daicel Ornex Co., Ltd.) ・Dipentaerythritol hexaacrylate 12 parts (DPHA, manufactured by Daicel Ornex Co., Ltd.) ・Photopolymerization initiator A 2 parts (Omnirad 184, manufactured by IGM Resins B.V.) ・Photopolymerization initiator C 2 parts (Omnirad 127, manufactured by IGM Resins B.V.) ・Crosslinked acrylic monodisperse microparticles A 2.5 parts (Techpolymer SSX-105, manufactured by Sekisui Chemical Co., Ltd., average particle size 5 μm) ・Crosslinked acrylic monodisperse microparticles B 0.85 parts (Techpolymer, manufactured by Sekisui Chemical Co., Ltd.) SSX-103 (average particle size 3 μm) ・Fluorine compound A with polymerizable groups 0.072 parts (Futergent 602A manufactured by Neos Co., Ltd., solid content concentration 50% by mass) ・Solvent (toluene) 50 parts ・Solvent (cyclohexanone) 14 parts 【0134】 [Example 4] An optical film of Example 4 was obtained under the same manufacturing conditions as in Example 3, except that an anti-glare coating solution 4 was used in which the anti-glare coating solution 3 was changed to contain 5 parts of crosslinked acrylic monodisperse fine particles A and 1.7 parts of crosslinked acrylic monodisperse fine particles B. 【0135】[Example 5] The anti-glare layer coating liquid 4 was cast onto a substrate (a 60 μm thick triacetylcellulose resin film, "Fujitac TG60UL" manufactured by Fujifilm Corporation) 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 liquid 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 5. 【0136】 [Example 6] An optical film of Example 6 was obtained using the same manufacturing conditions as in Example 3, except that the anti-glare 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). 【0137】 [Comparative Example 1] An optical film of Comparative Example 1 was obtained under the same manufacturing conditions as in Example 3, except that the anti-glare coating solution 6 of Example 3 was used, in which 3.35 parts of crosslinked acrylic monodisperse fine particles A and 3.35 parts of crosslinked acrylic monodisperse fine particles B were changed, and an anti-glare layer with a thickness of approximately 4 μm was formed using a wire bar (#10). 【0138】 [Comparative Example 2] An 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). 【0139】 [Comparative Example 3] An 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). 【0140】 Furthermore, each optical film in the examples and comparative examples was evaluated by measuring the following items. 【0141】[Number of protrusions] The number of protrusions on the surface 2a of the optical film 2, in the short-wavelength component with a cutoff value λc of 0.08 mm, that have a height of 0.1 μm or more and a longest diameter of 20 μm or more and 100 μm or less, is calculated by measuring the surface irregularities using optical interferometry under the following conditions with a surface and layer cross-sectional shape measurement system ("VertScan", manufactured by Ryoka Systems Co., Ltd., R3300G), calculating using the particle analysis function, and dividing by the measurement area (2057.23 μm × 1881.30 μm) to obtain 1 mm². ２ The number of convex parts per unit area was calculated. (Optical Conditions) Camera: Sony HR-57 1 / 2 inch Objective lens: 5x Imaging lens (lens barrel): 0.5x Zoom lens: 1x Wavelength filter: 530 white ND filter: Not used A-Stop (aperture diaphragm): Not used (fully open) F-Stop (field diaphragm): Not used (fully open) (Measurement Conditions) Measurement mode: Wave Scan range: -10 to 5 μm Effective pixels: 50% Measurement area: 2057.23 μm × 1881.30 μm (Correction Conditions) Interpolation correction: Full Baseline correction: Surface correction (polynomial approximation, 4th order) Filter: Gaussian (cutoff value 80 μm, high-pass image set as the main image) (Particle Analysis) Surface correction: None Analysis: Protrusion analysis Binarization threshold: 0.1 μm Particle shaping: None Target determination height base: Curved surface height: Upper limit 20 μm, lower limit 0 μm Longest diameter: Upper limit 100 μm, lower limit 20 μm Volume: Lower limit 0.0 μm ３ Aspect ratio: Lower limit 0.0 【0142】[Standard Deviation of Brightness Distribution of Display (Glare Value)] A smartphone (Samsung Galaxy S4) was used as the display device 1, and the optical film of each sample was attached to the display surface 16a of the display element 16 using optical adhesive. The resolution of the display element 16 of this smartphone is 441 ppi. Then, using a glare inspection machine manufactured by Komatsu NTC Corporation, the standard deviation of the brightness distribution (glare value) of the display element 16 was measured through the optical film of each sample. For this measurement, at least one of the exposure time of the imaging device 22 or the brightness of all pixels of the display element 16 was adjusted so that image data of a grayscale image with 8-bit gradation display and an average brightness of 170 gradations was obtained. In this way, the standard deviation of the brightness distribution of the display was measured in accordance with the method compliant with JIS C 1006:2019. The shooting conditions at this time were as follows. Lens 28 F-number: F8 Lens focal length: 12mm Y: 97.2μm X: 57.6μm Y / X: 1.69 Relative distance between lens 28 and display surface 16a (imaging distance): 328mm 【0143】 [10-point average roughness (RzJIS)] Measured in accordance with JIS B 0601:2013 using a contact-type surface roughness tester (Tokyo Seimitsu Co., Ltd. "Surfcom 1400G") under the following conditions: • Cutoff wavelength λc = 0.8 mm • Cutoff ratio λc / λs = 300 • Stylus: Diamond conical stylus with a tip radius of 2 μm and a vertex angle of 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. 【0144】 [Haze and Total Light Transmittance] These were measured using a haze meter (HM-150L2, manufactured by Murakami Color Technology Laboratory Co., Ltd.) in accordance with JIS K7136. Haze was measured with the surface having an uneven structure facing the light receiver. 【0145】[Anti-glare properties] 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 of the fluorescent lamp was visually inspected and evaluated according to the following criteria: ◎: The shape of the fluorescent lamp is not visible at all. ○: The outline of the fluorescent lamp is blurred. △: The outline of the fluorescent lamp is recognizable. 【0146】 The measurement results for each of the above items are shown in Table 1. 【0147】 【0148】 As shown in Table 1, the optical films of Examples 1 to 6 were shown to have good anti-glare properties and suppressed glare. Specifically, 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 6, the number of protrusions (spike-like protrusions) with a height of 0.1 μm or more and a longest diameter of 20 μm to 100 μm in the short-wavelength component when the cutoff value λc is 0.08 mm is 1 mm ２ It was found that the number of pixels per unit area was reduced to 100 or less, resulting in good anti-glare properties and suppressed glare. The reason for the suppression of glare is thought to be that the formation of protrusions that interfere with the pixels of the display device, such as spike-like protrusions, was suppressed, thereby suppressing the enlargement of the pixels of the display device due to the lens effect. 【0149】 On the other hand, 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, but the number of spike-like protrusions was 1 mm. ２ More than 100 of these were formed in one area, and the glare was not suppressed. 【0150】 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. 【0151】 The optical film of this disclosure has good anti-glare properties and suppressed glare, and is therefore suitable for use in display devices and optical components. 【0152】1 Display device 2 Optical film 2a Surface of optical film 3 Light-transmitting substrate 4 Anti-glare layer 4a Surface of anti-glare layer 5 Adhesive layer 6 Polarizing plate 7 Polarizing element 8 Phase difference film 10 Optical component 16 Display element 16a Display surface 17 Light source 18 Polarizing plate 20 Glare inspection machine 21 Housing 22 Imaging device 23 Holding part 24 Stand for imaging device 25 Stand for display device 27 Image processing device 28 Lens

Claims

1. An optical film having an uneven surface on one side, wherein the number of protrusions on the surface of the optical film having the uneven surface, in the short-wavelength component when the cutoff value λc is 0.08 mm, is 1 mm² or more, and the longest diameter is 20 μm or more and 100 μm or less. ２ Optical film, with fewer than 100 pieces per unit.

2. The optical film according to claim 1, 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.

3. The optical film according to claim 1 or 2, wherein the haze is 10% or less.

4. The optical film according to claim 1 or 2, comprising a light-transmitting substrate and an anti-glare layer.

5. The optical film according to claim 4, further comprising an anti-reflective layer on the anti-glare layer.

6. A display device comprising the optical film according to claim 1 or 2.

7. An optical member comprising the optical film described in claim 1 or 2.

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