Optical film, image display panel, and image display device

Abstract

Provided are an optical film, an image display panel, and an image display device. An optical film, wherein the optical film has a concave-convex surface, and with respect to the concave-convex surface, an interface development area ratio Sdr specified by ISO 25178-2:2012 is 0.010 or more and 0.060 or less, and a minimum autocorrelation length Sal specified by ISO 25178-2:2012 is 4.0 µm or more and 12.0 µm or less.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202380014703.7 (PCT / JP2023 / 016220), filed on April 25, 2023, entitled "Optical Film, Image Display Panel and Image Display Device". Technical Field

[0002] This disclosure relates to optical films, image display panels, and image display devices. Background Technology

[0003] In order to suppress the reflection of lighting and backgrounds such as people on the surface of image display devices such as televisions, laptop PCs, and desktop PC monitors, an optical film with an uneven surface is sometimes installed.

[0004] As optical films with uneven surfaces, for example, solutions such as Patent Document 1 to Patent Document 2 have been proposed.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. WO 2019 / 026466

[0008] Patent Document 2: International Publication No. WO 2019 / 026471 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] Conventional optical films achieve a specified anti-glare performance by increasing the surface roughness of the film. However, while optical films with increased surface roughness offer good anti-glare performance in the frontal direction, their anti-glare performance in the tilted direction is sometimes insufficient. Furthermore, optical films with increased surface roughness may exhibit reduced scratch resistance.

[0011] Furthermore, the optical films in Patent Documents 1 and 2 did not conduct any research on anti-glare properties and scratch resistance in the tilt direction.

[0012] The subject of this disclosure is to provide an optical film with good anti-glare properties in both the frontal and tilt directions, as well as good scratch resistance.

[0013] Methods for solving problems

[0014] This disclosure provides the following optical films, image display panels, and display devices [1] to [2].

[0015] [1] An optical film, wherein the optical film has an uneven surface, wherein the unfolded area ratio Sdr of the interface as specified by ISO 25178-2:2012 is 0.010 or more and 0.060 or less, and the minimum autocorrelation length Sal as specified by ISO 25178-2:2012 is 4.0 μm or more and 12.0 μm or less.

[0016] [2] An image display panel, wherein the image display panel is configured on a display element such that the surface of the optical film described in [1] faces the side opposite to the display element, and the optical film is configured on the outermost surface.

[0017] [3] An image display device, wherein the image display device includes the image display panel described in [2].

[0018] The effects of the invention

[0019] The optical film, image display panel, and image display device disclosed herein provide good anti-glare performance and scratch resistance in both frontal and tilt directions. Attached Figure Description

[0020] Figure 1 This is a schematic cross-sectional view illustrating one embodiment of the optical film of this disclosure.

[0021] Figure 2 This is a cross-sectional view illustrating one embodiment of the image display panel of this disclosure. Detailed Implementation

[0022] The embodiments of this disclosure will now be described.

[0023] [Optical film]

[0024] The optical film disclosed herein has an uneven surface.

[0025] Regarding the aforementioned uneven surface, the unfolded area ratio Sdr of the interface as specified in ISO 25178-2:2012 is 0.010 or more and 0.060 or less, and the minimum autocorrelation length Sal as specified in ISO 25178-2:2012 is 4.0 μm or more and 12.0 μm or less.

[0026] Figure 1 This is a schematic cross-sectional view of the cross-sectional shape of the optical film 100 disclosed herein.

[0027] Figure 1 The optical film 100 has an uneven surface. Figure 1The optical film 100 has a functional layer 20 on the substrate 10, and the surface of the functional layer 20 forms the uneven surface of the optical film. Additionally, Figure 1 The functional layer 20 has an anti-glare layer 21 and an anti-reflection layer 22.

[0028] Figure 1 It is a schematic cross-sectional view. That is, the scale of each layer constituting the optical film 100 and the scale of the uneven surface are schematic scales for ease of illustration and are different from the actual scale. Figure 2 The same.

[0029] Regarding the optical film of this disclosure, it is not limited to the specified range as long as the Sdr and Sal of the uneven surface are within the specified range. Figure 1 The optical film can be a single-layer structure of an anti-glare layer, or a two-layer structure of a substrate and an anti-glare layer, or it can have functional layers other than the anti-glare layer and the anti-reflective layer.

[0030] A preferred embodiment of the optical film is that it has a functional layer on a substrate, and the surface of the functional layer is the uneven surface. A more preferred embodiment of the optical film is that it includes an anti-glare layer as the functional layer, and the surface of the anti-glare layer is the uneven surface. A further preferred embodiment of the optical film is that it includes an anti-glare layer and an anti-reflection layer as the functional layer, and the surface of the anti-reflection layer is the uneven surface.

[0031] <Uneven Surface>

[0032] Optical films need to have uneven surfaces.

[0033] In addition, the uneven surface of the optical film needs to have the following characteristics: the unfolded area ratio Sdr of the interface as specified in ISO 25178-2:2012 is greater than or equal to 0.010 and less than 0.060, and the minimum autocorrelation length Sal as specified in ISO 25178-2:2012 is greater than or equal to 4.0 μm and less than 12.0 μm.

[0034] When the surface area of ​​the uneven surface is defined as A1, and the area of ​​the uneven surface projected onto the XY plane is defined as A0, Sdr is expressed by the following formula. The larger Sdr is, the more densely arranged the uneven surface is, or the larger the tilt angle of the uneven surface is, thus having a complex shape. Even for uneven surfaces with the same "arithmetic mean height Sa" (described later), there is a tendency that the more fine unevenness on the uneven surface, the larger the Sdr of the uneven surface is.

[0035] Sdr=(A1 / A0)-1

[0036] Sal is a parameter focusing on the lateral direction. A smaller Sal indicates a more densely packed surface texture, while a larger Sal indicates a surface with wider intervals between the bumps. Regarding the value of "average length RSm of roughness curve elements" as specified in JIS B0601, fine bumps have almost no effect; only large bumps have an impact. On the other hand, unlike RSm, Sal is affected not only by large bumps but also by fine bumps. Furthermore, even with wider bump intervals, Sal tends to decrease if the bumps are small or the bump shape is complex. Conversely, Sal tends to increase if the bumps have a monotonous shape.

[0037] When Sdr is less than 0.010, the shape of the uneven surface can be described as either a shape where the unevenness is not densely arranged or a shape with a small tilt angle. Therefore, when Sdr is less than 0.010, it is not possible to achieve good anti-glare performance in both the frontal and tilt directions.

[0038] Even with an Sdr value above 0.010, a Sal value exceeding 12.0 μm cannot achieve satisfactory anti-glare performance in the tilt direction. In the tilt direction, the increased reflectivity tends to reduce anti-glare performance. Furthermore, if Sal is too large, the surface becomes sparse, resulting in insufficient external scattering. Therefore, if Sal is too large, satisfactory anti-glare performance in the tilt direction cannot be achieved.

[0039] Even with an Sdr of 0.010 or higher but a Sal of less than 4.0 μm, good anti-glare performance in the tilt direction is not achievable. When visually viewing the optical film from a tilted position, a person can see an increase in the proportion of the area occupied by the top of the protrusion in the optical film's area. Furthermore, since the tilt is relatively gentle near the top of the protrusion, an increase in the proportion of the top of the protrusion in the optical film's area reduces anti-glare performance. Therefore, even with an Sdr of 0.010 or higher but a Sal of less than 4.0 μm, good anti-glare performance in the tilt direction is not achievable.

[0040] When Sdr exceeds 0.060, the shape of the uneven surface can be described as either an excessively dense arrangement of bumps and grooves, or a shape with excessively large tilt angles. The areas of the uneven surface damaged by friction are primarily near the protrusions. With an excessively dense arrangement of bumps and grooves, the increased number of protrusions makes the surface more susceptible to damage. Furthermore, with excessively large tilt angles, the strength of the protrusions tends to decrease. Therefore, when Sdr exceeds 0.060, good scratch resistance of the uneven surface is not achievable.

[0041] Furthermore, even when Sdr is below 0.060 but Sal is less than 4.0 μm, good scratch resistance is still not achievable. Damage to the surface caused by friction occurs primarily near the protrusions. When Sal is less than 4.0 μm, the increased number of protrusions on the surface makes it more susceptible to damage. Therefore, even when Sdr is below 0.060 but Sal is less than 4.0 μm, good scratch resistance is still not achievable.

[0042] The lower limit of Sdr is preferably 0.015 or higher, more preferably 0.020 or higher, and even more preferably 0.025 or higher. The upper limit of Sdr is preferably 0.050 or lower, more preferably 0.040 or lower, and even more preferably 0.035 or lower.

[0043] Examples of implementations for the range of Sdr include 0.010 and 0.060 and 0.010 and 0.050 and 0.010 and 0.040 and 0.010 and 0.035 and 0.015 and 0.060 and 0.015 and 0.050 and 0.015 and 0.040 and 0.015 and 0.035 and 0.020 and 0.060 and 0.020 and 0.050 and 0.020 and 0.040 and 0.020 and 0.035 and 0.025 and 0.060 and 0.025 and 0.050 and 0.025 and 0.040 and 0.025 and 0.035 and 0.025 and 0.060 and 0.025 and 0.050 and 0.025 and 0.040 and 0.025 and 0.035 and 0.025.

[0044] The lower limit of Sal is preferably 5.0 μm or more, more preferably 6.0 μm or more, and even more preferably 6.5 μm or more. The upper limit of Sal is preferably 10.0 μm or less, more preferably 9.0 μm or less, and even more preferably 8.5 μm or less.

[0045] Examples of implementations within the Sal range include 4.0 μm and above but less than 12.0 μm, 4.0 μm and above but less than 10.0 μm, 4.0 μm and above but less than 9.0 μm, 4.0 μm and above but less than 8.5 μm, 5.0 μm and above but less than 12.0 μm, 5.0 μm and above but less than 10.0 μm, 5.0 μm and above but less than 9.0 μm, 5.0 μm and above but less than 8.5 μm, 6.0 μm and above but less than 12.0 μm, 6.0 μm and above but less than 10.0 μm, 6.0 μm and above but less than 9.0 μm, 6.0 μm and above but less than 8.5 μm, 6.5 μm and above but less than 12.0 μm, 6.5 μm and above but less than 10.0 μm, 6.5 μm and above but less than 9.0 μm, and 6.5 μm and above but less than 8.5 μm.

[0046] Sdr and Sal, as well as Sxp and Sa (described later), are measured using a confocal laser microscope. Examples of confocal laser microscopes include the KEYENCE "VK-X" series. Furthermore, by using the aforementioned "Multi-File Analysis Application" of the "VK-X" series, Sdr, Sal, Sxp, and Sa can be easily calculated.

[0047] Regarding the measurement conditions when using the aforementioned "VK-X" series to measure Sdr, Sal, Sxp, and Sa, it is preferable to follow the conditions described in the embodiments. For example, the F-operation is preferably set to plane tilt correction (area specified). In addition, regarding the measurement area, it is preferable that one side is 50 μm or more and 200 μm or less, and regarding the measurement points, it is preferable that there are 500 or more and 2000 or less on each side.

[0048] With respect to the optical film of this disclosure, it is preferred that the pole height Sxp of the uneven surface, as defined by ISO 25178-2:2012, is 0.50 μm or more and 2.00 μm or less. Sxp is a parameter representing the difference between the average surface area of ​​the uneven surface and the convex portion after removing particularly high convex portions in the uneven surface.

[0049] Setting Sxp to 0.50μm or higher easily improves anti-glare performance in both the frontal and tilted directions. Setting Sxp to 2.00μm or lower easily improves scratch resistance.

[0050] The lower limit of Sxp is more preferably 0.80 μm or more, more preferably 1.00 μm or more, and more preferably 1.20 μm or more. The upper limit of Sxp is more preferably 1.80 μm or less, more preferably 1.50 μm or less, and more preferably 1.40 μm or less.

[0051] Implementations regarding the range of Sxp can include: 0.50 μm and above but less than 2.00 μm, 0.50 μm and above but less than 1.80 μm, 0.50 μm and above but less than 1.50 μm, 0.50 μm and above but less than 1.40 μm, 0.80 μm and above but less than 2.00 μm, 0.80 μm and above but less than 1.80 μm, 0.80 μm and above but less than 1.50 μm, and 0.80 μm and above. And below 1.40μm, above 1.00μm and below 2.00μm, above 1.00μm and below 1.80μm, above 1.00μm and below 1.50μm, above 1.00μm and below 1.40μm, above 1.20μm and below 2.00μm, above 1.20μm and below 1.80μm, above 1.20μm and below 1.50μm, and above 1.20μm and below 1.40μm.

[0052] In this specification, Sxp refers to the difference between a height with a load area ratio of 2.5% and a height with a load area ratio of 50%.

[0053] With respect to the optical film of this disclosure, it is preferred that the arithmetic mean height Sa of the uneven surface, as specified by ISO 25178-2:2012, is 0.20 μm or more and 1.00 μm or less.

[0054] Setting Sa to 0.20μm or higher easily improves anti-glare performance in the front direction. Setting Sa to 1.00μm or lower easily improves scratch resistance.

[0055] The lower limit of Sa is more preferably 0.25 μm or more, more preferably 0.30 μm or more, and more preferably 0.32 μm or more. The upper limit of Sa is more preferably 0.80 μm or less, more preferably 0.60 μm or less, and more preferably 0.40 μm or less.

[0056] Implementations regarding the range of Sa include: 0.20 μm and above and 1.00 μm and below; 0.20 μm and above and 0.80 μm and below; 0.20 μm and above and 0.60 μm and below; 0.20 μm and above and 0.40 μm and below; 0.25 μm and above and 1.00 μm and below; 0.25 μm and above and 0.80 μm and below; 0.25 μm and above and 0.60 μm and below; 0.25 μm and above and... Below 0.40μm, above 0.30μm and below 1.00μm, above 0.30μm and below 0.80μm, above 0.30μm and below 0.60μm, above 0.30μm and below 0.40μm, above 0.32μm and below 1.00μm, above 0.32μm and below 0.80μm, above 0.32μm and below 0.60μm, above 0.32μm and below 0.40μm.

[0057] In this specification, unless otherwise specified, the surface shape (Sdr, Sal, Sxp and Sa) and optical properties (haze, total transmittance, etc.) refer to the average value of the measurements taken at 16 locations.

[0058] In this specification, regarding the 16 measurement points, a region 1 cm from the outer edge of the sample is removed as a margin. For the remaining region, the 16 intersection points of lines dividing the longitudinal and transverse directions into 5 equal parts are used as the measurement centers. For example, in the case of a rectangular sample, a region 0.5 cm from the outer edge of the rectangle is removed as a margin, and the remaining region is measured using the 16 intersection points of dashed lines dividing the longitudinal and transverse directions into 5 equal parts as the centers. The average value is used to calculate the parameter. When the sample is a shape other than a rectangle, such as a circle, ellipse, triangle, or pentagon, simply draw the rectangle inscribed within these shapes and perform the 16 measurements using the method described above.

[0059] In this specification, surface shape (Sdr, Sal, Sxp, and Sa) and optical properties (haze, total transmittance, etc.), unless otherwise specified, are values ​​measured at a temperature of 23±5°C and a relative humidity of 40% to 65%. Furthermore, before each measurement, the sample is exposed to the aforementioned atmosphere for 30 to 60 minutes.

[0060] <Substrate>

[0061] For ease of manufacture and operability of the optical film, the optical film preferably has a substrate.

[0062] As a substrate, a substrate with excellent light transmittance, smoothness, heat resistance, and consequently, superior mechanical strength is preferred. Examples of such substrates include plastic films made of polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyethersulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl alcohol acetal, polyetherketone, polymethyl methacrylate, polycarbonate, polyurethane, and amorphous olefins (Cyclo-Olefin-Polymer: COP). The substrate can also be formed by laminating two or more plastic films together.

[0063] In plastic films, polyester films that have undergone stretching are preferred for mechanical strength and dimensional stability, and polyester films that have undergone biaxial stretching are more preferred. Examples of polyester films include polyethylene terephthalate films and polyethylene naphthalate films. TAC films and acrylic films are preferred because they readily exhibit good light transmittance and optical isotropy. COP films and polyester films are preferred because they offer excellent weather resistance.

[0064] The thickness of the substrate is preferably 5 μm or more and 300 μm or less, more preferably 20 μm or more and 200 μm or less, and even more preferably 30 μm or more and 120 μm or less.

[0065] When the goal is to thin the optical film, the preferred upper limit for the substrate thickness is 100 μm or less, and more preferably 80 μm or less. Furthermore, when the substrate is a low-moisture-permeable material such as polyester, COP, or acrylic, the preferred upper limit for the substrate thickness used for thinning is 60 μm or less, and more preferably 40 μm or less. Even in the case of large-screen displays, if the substrate thickness is within the aforementioned range, it is preferable to minimize the occurrence of deformation.

[0066] The thickness of the substrate can be measured using a film thickness gauge, for example. Examples of film thickness gauges include the Mitutoyo Digital Standard External Micrometer (model: MDC-25SX). Regarding the substrate thickness, the average value obtained from measuring any 10 points is sufficient.

[0067] Regarding the substrate, the total light transmittance according to JIS K7361-1:1997 is preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more.

[0068] Regarding the substrate, the haze of JIS K7136:2000 is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less.

[0069] To improve adhesion, the surface of the substrate can be subjected to physical treatments such as corona discharge treatment, or chemical treatments. Alternatively, the substrate can have an easy-to-adhere layer on its surface.

[0070] <Functional Layer>

[0071] Preferably, the optical film has a functional layer on the substrate, and the surface of the functional layer is the aforementioned uneven surface. Examples of functional layers include anti-glare layers, anti-reflective layers, antistatic layers, and anti-fouling layers.

[0072] More preferably, the optical film includes an anti-glare layer as a functional layer, the surface of which is the uneven surface. Even more preferably, the optical film includes an anti-glare layer and an anti-reflective layer as functional layers, the surface of which is the uneven surface.

[0073] Anti-glare layer

[0074] The anti-glare layer is the central layer responsible for anti-glare properties.

[0075] For anti-glare layers, they can be formed, for example, by (A) using an embossing roller, (B) etching, (C) mold-based forming, and (D) coating-based film formation. Among these methods, mold-based forming (C) is preferred for easily obtaining a stable surface shape, while coating-based film formation (D) is preferred for improving productivity and handling multiple product varieties.

[0076] In method (C), for example, an anti-glare layer can be formed by allowing resin to flow into a mold and removing the molded resin from the mold. The mold is a mold inverted to form the surface shape of the anti-glare layer. Such a mold can be manufactured, for example, by methods (c1-1) to (c1-2) or (c2) described below.

[0077] (c1-1) Create shapes for Sdr and Sal within a specified range using simulation. Then, invert the simulated shapes.

[0078] (c1-2) The metal is engraved using a laser in such a way that the inverted shape is reflected, thereby obtaining a mold.

[0079] (c2) A mold is obtained by reversing the shape of the anti-glare layer produced in (D) using a common electroforming method.

[0080] When forming an anti-glare layer by (D), methods (d1) and (d2) described below can be used as examples. (d1) is preferred in that it is easier to adjust the ranges of Sdr and Sal than (d2).

[0081] (d1) A method of applying and drying a coating liquid containing adhesive resin and particles to form an anti-glare layer with particle-based texture.

[0082] (d2) A method of coating an emulsion comprising any resin and a resin with poor compatibility with said resin, and separating the resin phases to form an uneven surface.

[0083] -thickness-

[0084] In order to achieve a balance with curl suppression, mechanical strength, hardness and toughness, the thickness T of the anti-glare layer is preferably 2.0 μm or more and 10.0 μm or less, more preferably 3.0 μm or more and 8.0 μm or less, and even more preferably 4.0 μm or more and 6.0 μm or less.

[0085] The thickness of the anti-glare layer can be calculated, for example, by selecting any 20 locations on a cross-sectional photograph of the optical film obtained using a scanning transmission electron microscope and averaging them. Preferably, the STEM accelerating voltage is 10 kV or higher and 30 kV or lower, and the STEM magnification is 1000x or higher and 7000x or lower.

[0086] -Element-

[0087] The anti-glare layer preferably mainly comprises resin components. Furthermore, the anti-glare layer preferably includes, as needed, additives such as: organic and inorganic particles, nanoparticles, refractive index modifiers, antistatic agents, antifouling agents, ultraviolet absorbers, light stabilizers, antioxidants, viscosity modifiers, and thermal polymerization initiators.

[0088] The anti-glare layer preferably comprises an adhesive resin and particles.

[0089] Regarding the particles, both organic and inorganic particles can be listed, with inorganic particles being preferred. That is, the anti-glare layer preferably comprises an adhesive resin and inorganic particles. Furthermore, the anti-glare layer more preferably comprises an adhesive resin, inorganic particles, and organic particles.

[0090] -Particles-

[0091] Examples of inorganic particles include silicon dioxide, alumina, zirconium oxide, and titanium dioxide, with silicon dioxide being the preferred choice. Among inorganic particles, amorphous inorganic particles are preferred, and amorphous silicon dioxide is more preferred.

[0092] As organic particles, particles containing one or more resins selected from polymethyl methacrylate, polyacrylic acid-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, organosilicon, fluorinated resin, and polyester resin can be listed.

[0093] The particles preferably do not contain particles with a large aspect ratio. This is because particles with a large aspect ratio tend to protrude from the surface of the anti-glare layer, which can sometimes reduce scratch resistance. Specifically, the particles preferably do not contain particles with an aspect ratio of 10 or higher, and more preferably, particles with an aspect ratio of 5 or higher.

[0094] Amorphous inorganic particles refer to inorganic particles that do not have a specific shape, obtained by crushing and classifying large-diameter inorganic particles.

[0095] The particles preferably include inorganic particles. Furthermore, the particles more preferably include amorphous inorganic particles, and even more preferably include both amorphous inorganic particles and organic particles. Amorphous silica is preferred as the amorphous inorganic particle.

[0096] Compared to spherical particles, amorphous inorganic particles are more likely to form fine irregularities. Therefore, amorphous inorganic particles tend to increase Sdr (size diameter) and decrease Sal (size value). However, if the particle size of the amorphous inorganic particles is too uniform, Sdr may not become sufficiently large, or Sal may become too small. Therefore, for amorphous inorganic particles, it is preferable that the cumulative distribution of particle size on a volume basis falls within the range described later. However, if inorganic particles are used alone, agglomeration is likely to occur. Therefore, to easily achieve Sdr and Sal within the aforementioned ranges, it is preferable that the particles comprise both amorphous inorganic particles with a defined particle size distribution and organic particles.

[0097] For inorganic particles such as amorphous inorganic particles, it is preferable that the cumulative distribution of particle size based on volume d10, the cumulative distribution of particle size based on volume d50, and the cumulative distribution of particle size based on volume d90 satisfy the following relationships (1) and (2).

[0098] 1.5≤d50 / d10≤4.0 (1)

[0099] 1.0≤d90 / d50≤3.0 (2)

[0100] A d50 / d10 ratio of 1.5 or higher indicates a wider particle size distribution of inorganic particles in regions with a particle size below the average. By setting d50 / d10 to 1.5 or higher, it is easier to impart fine texture to uneven surfaces, thus easily increasing Sdr. By setting d50 / d10 to 4.0 or lower, it is easier to suppress the increase in the amount of inorganic particles embedded in the anti-glare layer, thus easily increasing Sdr.

[0101] A d90 / d50 ratio of 1.0 or higher indicates a wider particle size distribution of inorganic particles in regions with particle sizes above the average. Setting d90 / 50 to 1.0 or higher makes it easier to increase the Sal (Size). Setting d90 / 50 to 3.0 or lower makes it easier to prevent the Sal from becoming excessively large.

[0102] The lower limit of d50 / 10 is more preferably 2.0 or above, even more preferably 2.3 or above, and the upper limit is more preferably 3.5 or below, even more preferably 3.0 or below.

[0103] The lower limit of d90 / d50 is more preferably 1.5 or more, even more preferably 1.8 or more, and the upper limit is more preferably 2.5 or less, even more preferably 2.0 or less.

[0104] The d10, d50, and d90 of inorganic particles, such as amorphous inorganic particles, can be measured by laser diffraction.

[0105] The cumulative distribution d50 of the particle size of inorganic particles, such as amorphous inorganic particles, based on volume is preferably 2.9 μm or more and 5.0 μm or less, more preferably 3.0 μm or more and 4.5 μm or less, and even more preferably 3.2 μm or more and 3.7 μm or less.

[0106] By setting d50 to 2.9 μm or higher, excessive increase in the number of inorganic particles can be suppressed, thus easily preventing Sdr from becoming too large or Sal from becoming too small. By setting d50 to 5.0 μm or lower, excessive decrease in the number of inorganic particles can be suppressed, thus easily preventing Sdr from becoming too small or Sal from becoming too large.

[0107] Regarding the thickness T of the anti-glare layer and the d50 of inorganic particles such as amorphous inorganic particles, d50 / T is preferably 0.60 or more and 1.00 or less, more preferably 0.65 or more and 0.90 or less, and even more preferably 0.67 or more and 0.80 or less. By making d50 / T within the aforementioned range, Sdr and Sal can be easily made to be within the aforementioned range.

[0108] The content of inorganic particles, such as amorphous inorganic particles, is preferably 10 parts by mass or more and 30 parts by mass or less, more preferably 15 parts by mass or more and 28 parts by mass or less, and even more preferably 18 parts by mass or more and 25 parts by mass or less, relative to 100 parts by mass of adhesive resin.

[0109] By making the content of inorganic particles, such as amorphous inorganic particles, more than 10 parts by mass, it is possible to suppress the excessive reduction of the number of inorganic particles, and thus it is easy to suppress Sdr from becoming too small or Sal from becoming too large.

[0110] By keeping the content of inorganic particles, such as amorphous inorganic particles, below 30 parts by mass, it is possible to suppress the excessive increase in the number of inorganic particles, thereby easily preventing Sdr from becoming too large or Sal from becoming too small.

[0111] The content of organic particles relative to 100 parts by weight of adhesive resin is preferably 2 parts by weight or more and 20 parts by weight or less, more preferably 5 parts by weight or more and 15 parts by weight or less, and even more preferably 10 parts by weight or more and 12 parts by weight or less.

[0112] By ensuring that the content of organic particles is 2 parts by mass or more, the aggregation of inorganic particles can be easily suppressed. Furthermore, by ensuring that the content of organic particles is 2 parts by mass or more, excessive reduction in the number of organic particles can be prevented, thus easily preventing Sdr from becoming too small or Sal from becoming too large.

[0113] By setting the content of organic particles to less than 20 parts by mass, excessive increase in the number of organic particles can be suppressed, thus easily preventing Sdr from becoming too large or Sal from becoming too small. Since the particle size distribution of organic particles is relatively uniform, an increase in the content of organic particles tends to result in a stronger tendency for Sal to decrease.

[0114] However, when there are two or more types of organic particles and the average particle size difference between the organic particles is large, there is a tendency for the SAL (sol) to become too large, regardless of the content of organic particles. Therefore, when using two or more types of organic particles, it is preferable to set the average particle size difference between the organic particles to 1.7 μm or less, more preferably 1.0 μm or less, more preferably 0.5 μm or less, more preferably 0.2 μm or less, and more preferably 0.1 μm or less.

[0115] The average particle size of the organic particles is preferably 1.0 μm or more and 5.0 μm or less, more preferably 1.2 μm or more and 3.0 μm or less, and even more preferably 1.3 μm or more and 2.5 μm or less.

[0116] By setting the average particle size of the organic particles to 1.0 μm or larger, it is possible to suppress an excessive increase in the number of organic particles, thus easily preventing Sdr from becoming too large or Sal from becoming too small. By setting the average particle size of the organic particles to 5.0 μm or smaller, it is possible to suppress an excessive decrease in the number of organic particles, thus easily preventing Sdr from becoming too small or Sal from becoming too large.

[0117] In this specification, the average particle size of organic particles refers to the value obtained as the volume average value d50 in laser diffraction.

[0118] Regarding organic particles, particles with a narrow particle size distribution are preferred. Specifically, for organic particles, the proportion of particles within a range of ±0.5 μm in average particle size is preferably 80% by volume or more, more preferably 85% by volume or more, and even more preferably 90% or more. By widening the particle size distribution of inorganic particles such as amorphous inorganic particles and narrowing the particle size distribution of organic particles, it is easy to make Sdr and Sal fall within the aforementioned ranges.

[0119] Organic particles can be shaped as spheres, discs, rugby balls, or irregular shapes. Among these shapes, spherical organic particles are preferred for easier control of particle size distribution.

[0120] The ratio of the average particle size of the organic particles to the thickness of the anti-glare layer (average particle size of organic particles / thickness of anti-glare layer) is preferably 0.20 or more and 0.70 or less, more preferably 0.23 or more and 0.50 or less, and even more preferably 0.25 or more and 0.40 or less. By making the ratio of the average particle size of the organic particles to the thickness of the anti-glare layer within the aforementioned range, it is easy to make Sdr and Sal within the aforementioned range.

[0121] -Inorganic particles-

[0122] In addition to adhesive resin and particles, the anti-glare layer may further contain inorganic microparticles. In this specification, inorganic microparticles are distinguished from the aforementioned particles by their average particle size.

[0123] By including inorganic microparticles in the anti-glare layer, the difference between the refractive index of the particles and the refractive index of the components of the anti-glare layer other than the particles is reduced, thereby making it easier to reduce internal haze.

[0124] As inorganic particles, examples include particles composed of silicon dioxide, aluminum oxide, zirconium oxide, and titanium dioxide. Among these, silicon dioxide, which easily suppresses the generation of internal haze, is preferred.

[0125] The average particle size of the inorganic microparticles is preferably 1 nm or more and 200 nm or less, more preferably 2 nm or more and 100 nm or less, and even more preferably 5 nm or more and 50 nm or less.

[0126] -Adhesive Resin-

[0127] To improve scratch resistance, the adhesive resin is preferably a cured product containing a thermosetting resin composition or a cured product containing an ionizing radiation-curing resin composition, and more preferably a cured product containing an ionizing radiation-curing resin composition.

[0128] The adhesive resin may include thermoplastic resins to the extent that it does not impair the effects of this disclosure.

[0129] As an adhesive component, inorganic adhesive components such as silica-based matrices can also be listed, but organic adhesive components are preferred. That is, regarding the adhesive component of the anti-glare layer of this disclosure, an adhesive resin as an organic adhesive component is preferred.

[0130] The ratio of the cured product of the curable resin composition to the total amount of the adhesive resin is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass.

[0131] A thermosetting resin composition is a composition that contains at least a thermosetting resin and is a resin composition that is cured by heating.

[0132] Examples of thermosetting resins include acrylic resins, polyurethane resins, phenolic resins, urea-melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. Curing agents are added to these curing resins as needed in thermosetting resin compositions.

[0133] Ionizing radiation-curable resin compositions are compositions containing compounds having ionizing radiation-curable functional groups (hereinafter also referred to as "ionizing radiation-curable compounds"). Examples of ionizing radiation-curable functional groups include olefinic unsaturated groups such as (meth)acryloyl, vinyl, and allyl, as well as epoxy and oxetyl groups. As ionizing radiation-curable compounds, compounds having olefinic unsaturated groups are preferred, compounds having two or more olefinic unsaturated groups are more preferred, and polyfunctional (meth)acrylate compounds having two or more olefinic unsaturated groups are even more preferred. As polyfunctional (meth)acrylate compounds, any of monomers and oligomers can be used.

[0134] Ionizing radiation refers to electromagnetic waves or charged particle beams that possess energy quanta capable of polymerizing or cross-linking molecules. Ultraviolet (UV) or electron (EB) beams are commonly used. In addition, electromagnetic waves such as X-rays and gamma rays, as well as charged particle beams such as alpha rays and ionizing rays can also be used.

[0135] Among polyfunctional (meth)acrylate compounds, difunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxydiacrylate, bisphenol A tetrapropoxydiacrylate, and 1,6-hexanediol diacrylate.

[0136] Examples of (meth)acrylate monomers with three or more functions include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol tetra(meth)acrylate, and isocyanuric acid modified tri(meth)acrylate.

[0137] The aforementioned (meth)acrylate monomers can be monomers whose molecular backbone has been modified. For example, the aforementioned (meth)acrylate monomers can also be monomers that have been modified by altering a portion of the molecular backbone using ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl groups, cyclic alkyl groups, aromatic groups, bisphenols, etc.

[0138] As multifunctional (meth)acrylate oligomers, examples include urethane (meth)acrylates, epoxy (meth)acrylates, polyester (meth)acrylates, polyether (meth)acrylates, and other acrylate polymers.

[0139] Regarding urethane (meth)acrylates, for example, they can be obtained by reacting polyols and organic diisocyanates with hydroxy (meth)acrylates.

[0140] Preferred epoxy (meth)acrylates are: (meth)acrylates obtained by reacting trifunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc., with (meth)acrylate; (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc., with polybasic acids and (meth)acrylate; and (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc., with phenols and (meth)acrylate.

[0141] The weight-average molecular weight of the polyfunctional (meth)acrylate oligomer is preferably 500 or more and 3000 or less, more preferably 700 or more and 2500 or less.

[0142] In this specification, the weight-average molecular weight is measured by GPC analysis and is the average molecular weight converted from standard polystyrene.

[0143] Furthermore, for purposes such as adjusting the viscosity of the anti-glare coating liquid, monofunctional (meth)acrylates can be used in combination as ionizing radiation curing compounds. Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and isobornyl (meth)acrylate.

[0144] For the aforementioned ionizing radiation-curing compounds, one type can be used alone or in combination of two or more types.

[0145] When the ionizing radiation curable compound is an ultraviolet curable compound, the ionizing radiation curable composition preferably contains additives such as photopolymerization initiators or photopolymerization accelerators.

[0146] As a photopolymerization initiator, one or more can be selected from acetophenone, benzophenone, α-hydroxyalkyl phenyl ketone, michaelone, benzoin, benzoyl dimethyl ketal, benzoylbenzoate, α-acyl oxime ester, thioxanone, etc.

[0147] Photopolymerization accelerators can reduce polymerization resistance caused by air during curing and thus accelerate the curing speed. Examples of accelerators include isoamyl p-dimethylaminobenzoate and ethyl p-dimethylaminobenzoate.

[0148] In the case where the adhesive resin contains a cured product of an ionizing radiation-curable resin composition, the ionizing radiation-curable resin composition preferably contains a polyfunctional (meth)acrylate monomer and a polyfunctional (meth)acrylate oligomer.

[0149] The mass ratio of the polyfunctional (meth)acrylate monomer to the polyfunctional (meth)acrylate oligomer is preferably 1:99 to 30:70, more preferably 5:90 to 20:80, and even more preferably 7:93 to 15:85.

[0150] By using a polyfunctional (meth)acrylate monomer in a specified proportion or higher, it is easy to achieve good scratch resistance in the anti-glare layer.

[0151] By increasing the proportion of polyfunctional (meth)acrylate oligomers to a specified level or higher, the viscosity of the coating liquid for the anti-glare layer can be increased, making it easier to prevent particles from settling below the anti-glare layer and to prevent the adhesive resin from flowing down between the particle-based protrusions. Therefore, Sdr and Sal can be easily adjusted to the aforementioned ranges. On the other hand, if the proportion of polyfunctional (meth)acrylate oligomers is too high, the strength of the anti-glare layer may sometimes decrease. Furthermore, if the viscosity of the coating liquid for the anti-glare layer is too high, Sdr may sometimes become too high, or Sal may become too low. Therefore, the ionizing radiation curable resin composition preferably contains a specified amount of polyfunctional (meth)acrylate oligomers and a specified amount of polyfunctional (meth)acrylate monomers.

[0152] To adjust viscosity or to allow the components to dissolve or disperse, the anti-glare coating liquid preferably contains a solvent. The surface shape of the coated and dried anti-glare layer varies depending on the type of solvent; therefore, it is preferable to select the solvent by considering factors such as its saturated vapor pressure and its permeability to the substrate.

[0153] Specifically, solvents can include, for example, ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), carbon halogens (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (isopropanol, butanol, cyclohexanol, etc.), cellosolvers (methyl cellosolvers, ethyl cellosolvers, etc.), glycol ethers (propylene glycol monomethyl ether acetate, etc.), cellosolve acetate esters, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), and mixtures thereof.

[0154] The solvent in the anti-glare coating solution is preferably a solvent with a fast evaporation rate as its main component. By accelerating the evaporation rate of the solvent, it is possible to suppress particle settling into the lower part of the anti-glare layer, thereby easily preventing the adhesive resin from flowing down between the particle-based protrusions. Therefore, Sdr and Sal can be easily adjusted to the ranges described above.

[0155] The main component refers to 50% or more by mass of the total amount of solvent, preferably 70% or more by mass, more preferably 90% or more by mass, and even more preferably 98% or more by mass.

[0156] In this specification, a solvent with a fast evaporation rate refers to a solvent with an evaporation rate of 100 or higher when the evaporation rate of butyl acetate is set to 100. More preferably, the evaporation rate of a solvent with a fast evaporation rate is 120 or higher and 300 or lower, and even more preferably 150 or higher and 220 or lower.

[0157] Examples of solvents with fast evaporation rates include methyl isobutyl ketone (evaporation rate of 160), toluene (evaporation rate of 200), and methyl ethyl ketone (evaporation rate of 370).

[0158] On the other hand, cyclohexanone (evaporation rate of 32) and propylene glycol monomethyl ether acetate (evaporation rate of 44) are examples of solvents with slow evaporation rates of less than 100.

[0159] When forming an anti-glare layer from an anti-glare coating liquid, it is preferable to control the drying conditions.

[0160] The drying conditions can be controlled by the drying temperature and the air velocity within the dryer. The drying temperature is preferably above 30°C and below 120°C, and the drying air velocity is preferably above 0.2 m / s and below 50 m / s. Furthermore, in order to control the surface shape of the anti-glare layer through drying, it is preferable to subject the coating liquid to ionizing radiation irradiation after drying.

[0161] Regarding drying conditions, it is preferable to perform two-stage drying within the aforementioned temperature and wind speed ranges. Furthermore, it is preferable that, compared to the first stage of drying, the second stage of drying involves a higher drying temperature and an increased wind speed. By performing drying slowly in the first stage, the shape of the amorphous inorganic particles can be easily reflected on the surface of the adhesive resin when the adhesive resin covers them. Additionally, by using a higher drying temperature and increasing the wind speed in the second stage than in the first stage, the agglomeration of organic particles can be easily suppressed. Therefore, by performing two-stage drying, Sdr and Sal can be easily controlled within the aforementioned ranges.

[0162] In the first stage of drying, it is preferable to set the drying temperature to 30°C or higher and less than 60°C, and the drying air velocity to 0.2 m / s or higher and less than 7 m / s. In the second stage of drying, it is preferable to set the drying temperature to 60°C or higher and less than 120°C, and the drying air velocity to 7 m / s or higher and less than 50 m / s.

[0163] Anti-reflective layer

[0164] To improve anti-glare performance, the functional layer preferably has an anti-reflective layer.

[0165] The surface of the anti-reflective layer is preferably the uneven surface of the optical film.

[0166] Examples of antireflective layers include: a single-layer structure with a low refractive index layer; a two-layer structure with a high refractive index layer and a low refractive index layer; and a multi-layer structure with three or more layers. The low refractive index layer and the high refractive index layer can be formed using common wet or dry processes. In the case of a wet process, the single-layer or two-layer structure is preferred, while in the case of a dry process, the multi-layer structure is preferred.

[0167] The wet process is superior to the dry process in terms of production efficiency and chemical resistance.

[0168] -Single-layer or two-layer structure-

[0169] A single-layer structure is a single layer of low refractive index, while a two-layer structure is formed by a high refractive index layer and a low refractive index layer. Single-layer or two-layer structures are preferably formed using a wet process.

[0170] Examples of methods for forming antireflective layers using wet processes include: methods using metal alkoxides or the like and forming them via a sol-gel method; methods forming them by coating with a low-refractive-index resin such as a fluororesin; and methods forming them by coating with a coating liquid containing low-refractive-index or high-refractive-index particles in an adhesive resin composition.

[0171] In wet processes, to improve adhesion and scratch resistance, it is preferable to use a coating liquid containing low-refractive-index or high-refractive-index particles in the adhesive resin composition to form the antireflective layer. Specifically, the low-refractive-index layer preferably comprises both an adhesive resin and low-refractive-index particles. Similarly, the high-refractive-index layer preferably comprises both an adhesive resin and high-refractive-index particles.

[0172] The low refractive index layer is preferably disposed on the outermost surface of the optical film.

[0173] When imparting antifouling properties to a low-refractive-index layer, it is preferable to include an antifouling agent such as an organosilicon compound or a fluorine compound in the low-refractive-index layer.

[0174] The lower limit of the refractive index of the low refractive index layer is preferably 1.10 or more, more preferably 1.20 or more, more preferably 1.26 or more, more preferably 1.28 or more, more preferably 1.30 or more, and the upper limit is preferably 1.48 or less, more preferably 1.45 or less, more preferably 1.40 or less, more preferably 1.38 or less, more preferably 1.32 or less.

[0175] In this specification, the refractive index refers to the value at a wavelength of 550 nm.

[0176] The lower limit of the thickness of the low refractive index layer is preferably 80 nm or more, more preferably 85 nm or more, more preferably 90 nm or more, and the upper limit is preferably 150 nm or less, more preferably 110 nm or less, more preferably 105 nm or less.

[0177] To improve scratch resistance, the adhesive resin of the low refractive index layer is preferably a cured product containing a thermosetting resin composition or a cured product containing an ionizing radiation-curing resin composition, and more preferably a cured product containing an ionizing radiation-curing resin composition.

[0178] The adhesive resin for the low refractive index layer may also include a thermoplastic resin to the extent that it does not impair the effects of this disclosure.

[0179] As a cured resin composition of a low refractive index layer, the cured resin composition can be the same as that exemplified in the anti-glare layer.

[0180] The proportion of the cured product of the curable resin composition to the total amount of the adhesive resin of the low refractive index layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 97% by mass or more.

[0181] The adhesive resin for the low-refractive-index layer may also include a thermoplastic resin. By including a thermoplastic resin as the adhesive resin, the viscosity of the coating liquid for the low-refractive-index layer is increased, and the coating liquid for the low-refractive-index layer is less likely to flow down into the gaps between the protrusions of the anti-glare layer. That is, by including a thermoplastic resin as the adhesive resin, even if a low-refractive-index layer is formed on the anti-glare layer, the surface shape of the anti-glare layer is easily maintained, and therefore Sdr and Sal can be easily adjusted to the aforementioned ranges. On the other hand, if the viscosity of the coating liquid for the low-refractive-index layer is too high, the following situation occurs: Sdr becomes too large, or Sal becomes too small.

[0182] For the aforementioned effects and coating strength, the content of thermoplastic resin is preferably 0.1% by mass or more and 3.0% by mass or less of the total amount of adhesive resin, more preferably 0.2% by mass or more and 1.5% by mass or less, and even more preferably 0.3% by mass or more and 0.7% by mass or less.

[0183] Examples of thermoplastic resins include polystyrene resins, polyolefin resins, ABS resins (including heat-resistant ABS resins), AS resins, AN resins, polyphenylene ether resins, polycarbonate resins, polyacetal resins, acrylic resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polysulfone resins, and polyphenylene sulfide resins. From the viewpoint of transparency, acrylic resins are preferred.

[0184] The weight-average molecular weight of the thermoplastic resin is preferably 20,000 or more and 200,000 or less, more preferably 30,000 or more and 150,000 or less, and even more preferably 50,000 or more and 100,000 or less.

[0185] Regarding low-refractive-index particles, hollow particles and solid particles can be cited. Low-refractive-index particles can consist of either hollow or solid particles, but it is preferable to include both. By including both hollow and solid particles, the reduction in coating strength can be suppressed, while the refractive index of the low-refractive-index layer can be easily and appropriately reduced. When prioritizing reducing the refractive index of the low-refractive-index layer, the low-refractive-index particles can be configured to include hollow particles but not solid particles.

[0186] The hollow and solid particles can be made of any inorganic or organic compound, such as silicon dioxide and magnesium fluoride, but silicon dioxide is preferred for low refractive index and strength.

[0187] The average primary particle size of the hollow particles is preferably smaller than the thickness of the low refractive index layer, for example, 1 nm or more and 150 nm or less. The average primary particle size of the hollow particles is preferably 35 nm or more and 100 nm or less, more preferably 50 nm or more and 100 nm or less, and even more preferably 60 nm or more and 80 nm or less.

[0188] The average primary particle size of the solid particles is preferably smaller than the thickness of the low refractive index layer, for example, 0.5 nm or more and 100 nm or less. The average primary particle size of the solid particles is preferably 1 nm or more and 30 nm or less, more preferably 5 nm or more and 20 nm or less, and even more preferably 10 nm or more and 15 nm or less.

[0189] When the average primary particle size of hollow particles is defined as X and the average primary particle size of solid particles is defined as Y, Y / X is preferably 0.10 or more and 0.30 or less, more preferably 0.13 or more and 0.25 or less, and even more preferably 0.15 or more and 0.20 or less. By setting Y / X to the aforementioned range, hollow particles and solid particles can be easily and uniformly distributed, and good scratch resistance can be easily achieved.

[0190] The average primary particle size of the hollow particles, the solid particles described later, and the high-refractive-index particles described later are calculated by the following operations (A1) to (A3).

[0191] (A1) The cross-section of the optical film was photographed using STEM. The accelerating voltage of STEM was 10kV to 30kV, and the magnification was 50,000 to 300,000 times.

[0192] (A2) Extract any 10 particles from the observed image and calculate the particle size of each particle. When the cross-section of each particle is sandwiched between any two parallel straight lines, the distance between the two lines that is the largest is taken as the particle size of each particle.

[0193] (A3) Perform the same operation 5 times in another image of the same sample, and take the average value of the total 50 particle sizes as the average first particle size.

[0194] The higher the content of hollow particles, the higher the filling rate of hollow particles in the adhesive resin, and the lower the refractive index of the low-refractive-index layer. Therefore, the content of hollow particles relative to 100 parts by weight of adhesive resin is preferably 100 parts by weight or more, and more preferably 150 parts by weight or more.

[0195] On the other hand, if the content of hollow particles is too high, the hollow particles are easily damaged or detached, which tends to reduce the mechanical strength, such as the scratch resistance of the low refractive index layer. Therefore, the content of hollow particles is preferably 300 parts by weight or less, more preferably 250 parts by weight or less, relative to 100 parts by weight of adhesive resin.

[0196] In order to ensure good scratch resistance of the low refractive index layer, the content of solid particles is preferably 20 parts by weight or more, more preferably 40 parts by weight or more, relative to 100 parts by weight of adhesive resin.

[0197] On the other hand, if the content of solid particles is too high, the solid particles are prone to agglomeration. Therefore, the content of solid particles is preferably 100 parts by weight or less relative to 100 parts by weight of adhesive resin, and more preferably 60 parts by weight or less.

[0198] When the content of adhesive resin per 100 parts by mass of hollow particles is defined as A, and the content of adhesive resin per 100 parts by mass of solid particles is defined as B, B / A is preferably 0.15 or more and 0.40 or less, more preferably 0.17 or more and 0.35 or less, and even more preferably 0.20 or more and 0.30 or less. By setting B / A within the aforementioned range, hollow particles and solid particles can be easily and uniformly distributed, and good scratch resistance can be easily achieved.

[0199] The high refractive index layer is preferably positioned closer to the anti-glare layer than the low refractive index layer.

[0200] The lower limit of the refractive index of the high refractive index layer is preferably 1.53 or higher, more preferably 1.54 or higher, more preferably 1.55 or higher, more preferably 1.56 or higher, and the upper limit is preferably 1.85 or lower, more preferably 1.80 or lower, more preferably 1.75 or lower, more preferably 1.70 or lower.

[0201] The upper limit of the thickness of the high refractive index layer is preferably below 200 nm, more preferably below 180 nm, even more preferably below 150 nm, and the lower limit is preferably above 50 nm, more preferably above 70 nm.

[0202] As adhesive resins for high refractive index layers, the same adhesive resins as those for low refractive index layers can be listed.

[0203] Examples of high refractive index particles include antimony pentoxide, zinc oxide, titanium oxide, cerium oxide, tin-doped indium oxide, antimony-doped tin oxide, yttrium oxide, and zirconium oxide.

[0204] The average primary particle size of the high refractive index particles is preferably 2 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more. Furthermore, from the viewpoint of suppressing whitening and improving transparency, the average primary particle size of the high refractive index particles is preferably 200 nm or less, more preferably 100 nm or less, more preferably 80 nm or less, more preferably 60 nm or less, and even more preferably 30 nm or less.

[0205] Regarding the content of high refractive index particles, it is sufficient to set it to a content that makes the refractive index of the high refractive index layer fall within the range mentioned above.

[0206] When forming antireflective layers such as low-refractive-index and high-refractive-index layers using a wet process, it is preferable to increase the viscosity of the coating liquid for the antireflective layer. By increasing the viscosity of the coating liquid, the antireflective layer coating liquid is less likely to flow down into the gaps between the protrusions of the anti-glare layer. Therefore, even when an antireflective layer is formed on the anti-glare layer, the surface shape of the anti-glare layer can be easily maintained. Therefore, by appropriately increasing the viscosity of the coating liquid for the antireflective layer, Sdr and Sal can be easily adjusted to the aforementioned ranges. For example, the viscosity of the coating liquid for the antireflective layer can be increased by adding a thermoplastic resin as a binder resin, increasing the proportion of oligomers as an ionizing radiation curable resin composition, or selecting a high-viscosity solvent.

[0207] On the other hand, the surface of anti-glare layers often has a long period of unevenness and a fine unevenness overlapping the aforementioned unevenness. If the viscosity of the coating liquid for the anti-reflective layer is increased excessively, the aforementioned fine unevenness can easily be filled in, making it sometimes difficult to adjust Sdr and Sal to the ranges described above.

[0208] Therefore, the viscosity of the coating liquid for the antireflective layer at 23°C is preferably 0.1 mPa·s or higher and 5.0 mPa·s or lower.

[0209] As a solvent for the coating liquid used in the anti-reflective layer, the same solvents as those exemplified as solvents for the coating liquid used in the anti-glare layer can be listed.

[0210] When forming an anti-glare layer from an anti-reflective coating liquid, it is preferable to control the drying conditions.

[0211] Drying conditions can be controlled by the drying temperature and the air velocity within the dryer. The drying temperature is preferably 30°C or higher and 70°C or lower, and the drying air velocity is preferably 10 m / s or higher and 30 m / s or lower. By setting the drying temperature to a low level, the viscosity of the coating liquid for the anti-reflective layer can be easily increased. Furthermore, by increasing the air velocity, the viscosity of the coating liquid for the anti-reflective layer can be rapidly increased. Therefore, by drying the coating liquid for the anti-reflective layer at a lower temperature and a stronger air velocity, the surface shape of the anti-glare layer can be easily maintained. That is, by drying the coating liquid for the anti-reflective layer at a lower temperature and a stronger air velocity, Sdr and Sal can be easily controlled.

[0212] Preferably, the anti-reflective layer is irradiated with ionizing radiation after the coating liquid has dried.

[0213] -Multi-layer structures with 3 or more layers--

[0214] The multilayer structure preferably formed by the dry process is a structure consisting of three or more layers of alternating high-refractive-index and low-refractive-index layers. In the multilayer structure, the low-refractive-index layer is also preferably disposed on the outermost surface of the optical film.

[0215] Regarding the high refractive index layer, the thickness is preferably 10 nm or more and 200 nm or less, and the refractive index is preferably 2.10 or more and 2.40 or less. More preferably, the thickness of the high refractive index layer is 20 nm or more and 70 nm or less.

[0216] Regarding the low refractive index layer, the thickness is preferably 5 nm or more and 200 nm or less, and the refractive index is preferably 1.33 or more and 1.53 or less. More preferably, the thickness of the low refractive index layer is 20 nm or more and 120 nm or less.

[0217] <Optical Properties>

[0218] The total transmittance of the optical film according to JIS K7361-1:1997 is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more.

[0219] When measuring total transmittance and haze, the light incident surface is the side opposite to the uneven surface.

[0220] The haze of the optical film according to JIS K7136:2000 is preferably 20% or more and 75% or less. The lower limit of haze is more preferably 30% or more, further preferably 40% or more, even more preferably 50% or more, and the upper limit is more preferably 70% or less, and even more preferably 65% ​​or less.

[0221] By setting the haze level to 20% or higher, good anti-glare performance can be easily achieved. Furthermore, by setting the haze level to 75% or lower, image resolution degradation can be easily suppressed.

[0222] Examples of implementations for the haze of optical films include 20% or more and 75% or less, 20% or more and 70% or less, 20% or more and 65% or less, 30% or more and 75% or less, 30% or more and 70% or less, 30% or more and 65% or less, 40% or more and 75% or less, 40% or more and 70% or less, 40% or more and 65% or less, 50% or more and 75% or less, 50% or more and 70% or less, and 50% or more and 65% or less.

[0223] In order to easily achieve good image resolution and contrast, the internal haze of the optical film is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less.

[0224] Internal haze can be measured using common methods, such as bonding a transparent sheet to an uneven surface with a transparent adhesive layer and then crushing the uneven surface. The difference between the refractive index of the adhesive layer and the refractive index of the adhesive resin should be less than 0.05.

[0225] Regarding optical films, the transmitted image sharpness is measured according to JIS K7374:2007. The transmitted image sharpness with a comb width of 0.125 mm is defined as C. 0.125 The sharpness of a transmitted image with a comb width of 0.25 mm is defined as C. 0.25 The sharpness of a transmitted image with a comb width of 0.5 mm is defined as C. 0.5 The sharpness of a transmitted image with a comb width of 1.0 mm is defined as C. 1.0 The sharpness of a transmitted image with a comb width of 2.0 mm is defined as C. 2.0 At that time, C 0.125 C 0.25C 0.5 C 1.0 And C 2.0 The value is preferably within the range described below.

[0226] To ensure good anti-glare performance, C 0.125 Preferably, it is 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. To achieve good resolution, C 0.125 Preferably, it is 1.0% or higher. As C 0.125 The range can be listed as 1.0% or more and less than 50%, 1.0% or more and less than 40%, 1.0% or more and less than 30%, and 1.0% or more and less than 20%.

[0227] To ensure good anti-glare performance, C 0.25 Preferably, it is 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. To achieve good resolution, C 0.25 Preferably, it is 1.0% or higher. As C 0.25 The range can be listed as 1.0% or more and less than 50%, 1.0% or more and less than 40%, 1.0% or more and less than 30%, and 1.0% or more and less than 20%.

[0228] To ensure good anti-glare performance, C 0.5 Preferably, it is 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. To achieve good resolution, C 0.5 Preferably, it is 1.0% or higher. As C 0.5 The range can be listed as 1.0% or more and less than 50%, 1.0% or more and less than 40%, 1.0% or more and less than 30%, and 1.0% or more and less than 20%.

[0229] To ensure good anti-glare performance, C 1.0 Preferably, it is 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. To achieve good resolution, C 1.0 Preferably, it is 1.0% or higher. As C 1.0 The range can be listed as 1.0% or more and less than 50%, 1.0% or more and less than 40%, 1.0% or more and less than 30%, and 1.0% or more and less than 20%.

[0230] To ensure good anti-glare performance, C 2.0 Preferably, it is 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. To achieve good resolution, C 2.0 Preferably, it is 5.0% or higher. As C 2.0The range can be listed as 5.0% or more and less than 50%, 5.0% or more and less than 40%, 5.0% or more and less than 30%, and 5.0% or more and less than 20%.

[0231] Regarding optical films, in order to achieve good anti-glare performance, C 0.125 C 0.5 C 1.0 And C 2.0 The total percentage is preferably 200% or less, more preferably 150% or less, more preferably 100% or less, and even more preferably 80% or less. For good resolution, the aforementioned total percentage is preferably 10.0% or more. Examples of the aforementioned total percentage range include 10.0% or more and 200% or less, 10.0% or more and 150% or less, 10.0% or more and 100% or less, and 10.0% or more and 80% or less.

[0232] <Size, shape, etc.>

[0233] Optical films can be in the form of single sheets cut to a specified size, or in the form of rolls formed by rolling long strips of material into rolls. There is no particular limitation on the size of a single sheet, but the maximum diameter is approximately 2 inches to 500 inches. "Maximum diameter" refers to the maximum length that can be drawn connecting any two points on the optical film. For example, in the case of a rectangular optical film, the diagonal of that area becomes the maximum diameter. In the case of a circular optical film, the diameter of the circle becomes the maximum diameter.

[0234] There are no particular limitations on the width and length of the roll, but generally the width is between 500 mm and 3000 mm, and the length is between 500 m and 5000 m. For roll-shaped optical films, they can be cut into single sheets according to the size of the image display device, etc. When cutting, it is preferable to remove the ends of the roll that have unstable physical properties.

[0235] The shape of the single film is not particularly limited; for example, it can be triangular, quadrilateral, pentagonal, polygonal, circular, or random irregular shapes. More specifically, when the optical film is quadrilateral, the aspect ratio is not particularly limited as long as it works for display purposes. For example, aspect ratios such as 1:1, 4:3, 16:10, 16:9, and 2:1 can be listed, but for more sophisticated applications such as automotive or digital signage, these aspect ratios are not strictly limited.

[0236] The surface shape of the side of the optical film opposite to the uneven surface is not particularly limited, but it is preferably generally smooth. Generally smooth means that the arithmetic mean roughness Ra of JIS B0601:1994 at a cutoff value of 0.8 mm is less than 0.03 μm, preferably less than 0.02 μm.

[0237] The optical film disclosed herein can be suitably used as an optical component on the light emitting surface side of a display element, and in particular, it can be suitably used as an optical component disposed on the outermost surface of an image display panel or an image display device.

[0238] [Image Display Panel]

[0239] The image display panel of this disclosure is configured on a display element such that the surface of the optical film described above faces the side opposite to the display element, and the optical film is disposed on the outermost surface (see reference). Figure 2 ).

[0240] As display elements, examples include liquid crystal display elements, EL display elements (organic EL display elements, inorganic EL display elements), plasma display elements, and further include LED display elements such as micro LED display elements. These display elements may also have touch panel functionality inside the display element.

[0241] Liquid crystal displays (LCDs) can be displayed using various methods, including IPS, VA, multi-domain, OCB, STN, and TSTN. When the display element is a liquid crystal display (LCD), a backlight is required. The backlight is positioned on the side of the LCD element opposite to the side where the optical film is located.

[0242] Alternatively, the image display panel disclosed herein can also be an image display panel with a touch panel, which has a touch panel between the display element and the optical film. In this case, it is sufficient to arrange the optical film on the outermost surface of the image display panel with the touch panel, and to arrange the surface of the optical film with its concave and convex surfaces facing the side opposite to the display element.

[0243] There is no particular limit to the size of the image display panel, but the maximum diameter is approximately 2 inches or more and less than 500 inches. The maximum diameter refers to the maximum length that can be achieved by connecting any two points within the surface of the image display panel.

[0244] [Image display device]

[0245] The image display device disclosed herein includes the image display panel described above.

[0246] In an image display device, an optical film is disposed on the outermost surface of the image display device.

[0247] The image display device disclosed herein preferably further comprises: a drive control unit electrically connected to the image display panel; and a housing for housing the image display panel and the drive control unit, etc.

[0248] When the display element is a liquid crystal display element, a backlight is required in the image display device of this disclosure. The backlight is disposed on the side of the liquid crystal display element opposite to the light emitting surface side.

[0249] There is no particular limitation on the size of the image display device, but the maximum diameter of the effective display area is approximately 2 inches or more and less than 500 inches.

[0250] The effective display area of ​​an image display device refers to the area capable of displaying an image. For example, in the case where the image display device has a housing surrounding the display element, the area inside the housing becomes the effective image area.

[0251] Furthermore, the maximum diameter of the effective image region refers to the maximum length that connects any two points within the effective image region. For example, if the effective image region is rectangular, the diagonal of that region becomes the maximum diameter. Conversely, if the effective image region is circular, the diameter of that region becomes the maximum diameter.

[0252] This disclosure includes the following [1] to

[13] .

[0253] [1] An optical film, wherein,

[0254] The optical film has an uneven surface.

[0255] Regarding the aforementioned uneven surface, the unfolded area ratio Sdr of the interface as specified in ISO 25178-2:2012 is 0.010 or more and 0.060 or less, and the minimum autocorrelation length Sal as specified in ISO 25178-2:2012 is 4.0 μm or more and 12.0 μm or less.

[0256] [2] According to the optical film of [1], wherein, with respect to the uneven surface, the pole height Sxp as specified by ISO 25178-2:2012 is 0.50 μm or more and 2.00 μm or less.

[0257] [3] The optical film according to [1] or [2], wherein, with respect to the uneven surface, the arithmetic mean height Sa as specified by ISO 25178-2:2012 is 0.20 μm or more and 1.00 μm or less.

[0258] [4] An optical film according to any one of [1] to [3], wherein the optical film has a functional layer on a substrate and the surface of the functional layer is the uneven surface.

[0259] [5] According to the optical film described in [4], wherein the optical film includes an anti-glare layer as the functional layer, and the surface of the anti-glare layer is the uneven surface.

[0260] [6] According to the optical film described in [4], the optical film includes an anti-glare layer and an anti-reflection layer as the functional layer, and the surface of the anti-reflection layer is the uneven surface.

[0261] [7] The optical film according to [5] or [6], wherein the anti-glare layer comprises an adhesive resin and particles.

[0262] [8] The optical film according to [7], wherein the optical film comprises amorphous inorganic particles as said particles.

[0263] [9] The optical film according to [8] further comprises organic particles as said particles.

[0264]

[10] The optical film according to any one of [7] to [9], wherein the adhesive resin comprises a cured product of an ionizing radiation curable resin composition.

[0265]

[11] The optical film according to any one of [1] to

[10] , wherein the haze of JIS K7136:2000 is 20% or more and 75% or less.

[0266]

[12] An image display panel, wherein the image display panel is configured on a display element such that the surface of the uneven surface of the optical film described in any one of [1] to

[11] faces the side opposite to the display element, and the optical film is disposed on the outermost surface.

[0267]

[13] An image display device, wherein the image display device comprises the image display panel described in

[12] .

[0268] Example

[0269] The present disclosure will now be described in more detail by way of examples, but the present disclosure is not limited to these examples in any way. Furthermore, unless otherwise specified, “parts” and “%” are mass measurements.

[0270] 1. Measurement and Evaluation

[0271] The optical films of the Examples and Comparative Examples were measured and evaluated as follows. The atmosphere for each measurement and evaluation was: temperature 23±5°C, relative humidity 40% or more and 65% or less. Furthermore, before each measurement and evaluation, the sample was exposed to the atmosphere for 30 minutes to 60 minutes, and then the measurement and evaluation were performed. The results are shown in Table 1 or 2.

[0272] 1-1. Measurement of Surface Shape

[0273] The optical films of the examples and comparative examples were cut into 10cm × 10cm pieces. For the cut sections, after visually confirming that there were no abnormalities such as dirt or scratches, cut sections were randomly selected. Sample 1 was fabricated as follows: the substrate side of the cut optical film was bonded to a glass plate (2.0mm thick) measuring 10cm × 10cm using an optically transparent adhesive sheet (trade name: Panaclean PD-S1, thickness 25μm) from PANAC Corporation.

[0274] Using a confocal laser microscope (VK-X250 (control unit) and VK-X260 (measurement unit)), with sample 1 fixed and in close contact with the measurement stage, the surface shape of the anti-glare film was measured and analyzed under the following measurement conditions 1, image processing conditions 1, and analysis conditions 1. Furthermore, a multi-file analysis application (version 1.3.1.120) was used for the analysis software. The surface shape measurement was performed in a vibration-free environment (it is also possible to measure the surface shape in an environment where vibration is suppressed, such as using a vibration-damping stage).

[0275] (Measurement Condition 1)

[0276] Laser wavelength: 408nm

[0277] Measurement optical system: confocal optical system

[0278] Objective lens: 150x

[0279] Zoom: 1x

[0280] Measurement area: 93.95μm × 70.44μm

[0281] Number of measurement points: 1024 × 768 points

[0282] Measurement conditions: transparent body surface shape / high precision / dual scanning present

[0283] (Image processing condition 1)

[0284] • DCL / BCL: DCL = 13000, BCL = 65535, processing method: supplement from surrounding pixels.

[0285] • Altitude cutoff level: Strong

[0286] (Analysis condition 1)

[0287] • Region: The entire region

[0288] • Filter category: Gaussian

[0289] • S-filter: 0.25μm

[0290] • F- Operation: Plane Tilt Correction (Region Specifying)

[0291] • L-filter: None

[0292] • Terminal effect calibration: ON

[0293] • When calculating Sxp, p and q are: p = 2.5%; q = 50.0%.

[0294] • When calculating Sal, s = 0.20

[0295] The analysis software displays "Sdr", "Sal", "Sxp", and "Sa" for each measurement area and uses them as measurement values.

[0296] 1-2. Haze (Hz)

[0297] The optical films of the examples and comparative examples were cut into 10cm squares. For the cut sections, after visually confirming that there were no abnormalities such as dirt or scratches, cut sections were randomly selected. The haze of each sample according to JIS K7136:2000 was measured using a haze meter (HM-150, Murakami Color Technology Research Institute).

[0298] After turning on the power switch of the device in a manner that stabilizes the light source, wait for more than 15 minutes, perform calibration without setting anything in the inlet opening, and then set the measurement sample in the inlet opening for measurement. Set the light incident surface to the substrate side.

[0299] Furthermore, the total light transmittance of the optical films in both the examples and the comparative examples is 90% or higher.

[0300] 1-3. Transmission image sharpness

[0301] The optical films of the examples and comparative examples were cut into 10cm squares. For the cut sections, after visually confirming the absence of dirt, scratches, or other abnormalities, cut sections were randomly selected. The transmitted image sharpness of the samples was measured using an image quality measuring instrument (trade name: ICM-1T) manufactured by Suga Testing Machine Co., Ltd., according to JIS K7374:2007. The widths of the optical comb were 0.125mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm. The light incident surface during measurement was set to the transparent substrate side. C 0.125 C 0.25 C 0.5 C 1.0 And C 2.0 The value of C 0.125 C 0.5 C 1.0 And C 2.0 The total values ​​are shown in Table 2.

[0302] 1-4. Anti-glare performance from the front

[0303] The optical films of the examples and comparative examples were cut into 10cm × 10cm pieces. For the cut sections, after visually confirming that there were no abnormalities such as dirt or scratches, cut sections were randomly selected. Sample 2 was fabricated as follows: the substrate side of the cut optical film was bonded to a 10cm × 10cm black plate (Kuraray, Comoglass DFA2CG 502K (black) series, 2mm thick) using an optically transparent adhesive sheet (panaclean PD-S1) from PANAC.

[0304] In a brightly lit environment, on a horizontal platform 70 cm high, sample 2 was positioned with its uneven surface facing upwards. The sample was positioned approximately directly below the illumination source. The illumination reflection onto the uneven surface was evaluated from the front (with the observer not obstructing the illumination) according to the following evaluation criteria.

[0305] For illumination, a straight-tube, three-wavelength daylight fluorescent lamp of type Hf32 was used, positioned at a height of 2 m vertically above a horizontal platform. Evaluation was conducted within an illuminance range of 500 lux to 1000 lux on the uneven surface of the sample. The observer's line of sight was approximately 120 cm above the ground. The observer was a healthy adult in their 30s with visual acuity of 0.7 or better.

[0306] <Evaluation Criteria>

[0307] A: The outline is not illuminated, and the location is unknown.

[0308] B: Although there is no illuminated outline, the location is vaguely discernible.

[0309] C: The outline and position of the lighting are vaguely discernible.

[0310] D: The lighting outline is relatively clear, and the location is also clearly known.

[0311] 1-5. Anti-glare performance in the tilt direction

[0312] Regarding the samples, Sample 2, prepared in sections 1-4, was used. In a brightly lit environment, Sample 2 was positioned with its uneven surface facing upwards on a horizontal platform 70 cm high. The sample was positioned at a 60-degree angle between the direction connecting the sample and the illumination and the normal direction of the horizontal platform. The illumination light's reflection into the uneven surface was evaluated according to the following evaluation criteria, starting from the direction from which the illumination appears to be most intensely reflected into the sample. (Note: The direction from which the illumination appears to be most intensely reflected into the sample was predetermined using a blackboard without uneven surfaces as a reference. Specifically, the reference was placed at the aforementioned sample position, and the direction from which the illumination appears to be most intensely reflected into the reference was identified. This direction was then used to evaluate each sample.)

[0313] For illumination, an Hf32 type straight-tube three-wavelength daylight fluorescent lamp was used, positioned at a height of 2m vertically above a horizontal platform. Evaluation was conducted within an illuminance range of 500 lux to 1000 lux on the uneven surface of the sample. The observer's line of sight was approximately 100cm above the ground. The observers were healthy individuals in their 30s with visual acuity of 0.7 or better.

[0314] <Evaluation Criteria>

[0315] A: The outline is not illuminated, and the location is unknown.

[0316] B: Although there is no illuminated outline, the location is vaguely discernible.

[0317] C: The outline and position of the lighting are vaguely discernible.

[0318] D: The lighting outline is relatively clear, and the location is also clearly known.

[0319] 1-6. Scratch resistance

[0320] Regarding the sample, Sample 2, prepared in sections 1-4, was used. Sample 2 was fitted onto the base of the vibration abrasion testing machine (manufactured by TESTER SANGYO Co., Ltd., trade name "AB-301") with the uneven surface as the upper surface. Steel wool #0000 (manufactured by Nippon Steel Wool Co., Ltd., trade name "BONSTAR B-204") was used. The steel wool was brought into contact with the uneven surface, and a load was applied while the steel wool was moved back and forth 10 times at a moving speed of 100 mm / s and a reciprocating distance of 200 mm per cycle. The contact area between the steel wool and the sample was set to 1 cm². 2 .

[0321] Then, the number of scratches was confirmed by visual observation of each sample under fluorescent lighting. At this time, the illuminance on the sample was above 800 lux and below 1200 lux, and the observation distance was 30 cm.

[0322] For each sample, the maximum load per unit area (g / cm²) was confirmed when no damage was observed after the test. 2 For each sample, tests were conducted with n=2, the average value of the maximum load was calculated, and the results were evaluated according to the following criteria.

[0323] <Evaluation Criteria>

[0324] A: The maximum load is 300g / cm² 2 above

[0325] B: Maximum load is 200g / cm 2 Above and less than 300g / cm 2

[0326] C: Maximum load less than 200g / cm 2

[0327] 1-7. Overall Evaluation

[0328] Based on three evaluation criteria—anti-glare performance in the frontal direction, anti-glare performance in the tilted direction, and scratch resistance—a comprehensive evaluation was conducted according to the following standards.

[0329] <Evaluation Criteria>

[0330] A: All three evaluations are A.

[0331] B: Of the three evaluations, two were A and one was B.

[0332] C: All three evaluations are B. Or, two of the three evaluations are B and one is A.

[0333] D: If any one of the three evaluations is C or D.

[0334] 2. Fabrication of optical films

[0335] [Example 1]

[0336] The anti-glare coating liquid 1 described below was applied to a substrate (80 μm thick triacetyl cellulose resin film, Fujifilm, TD80UL). Next, it was dried at 50°C and 5 m / s for 30 seconds, and then further dried at 70°C and 10 m / s for 45 seconds. Then, it was subjected to a nitrogen atmosphere with an oxygen concentration of 200 ppm or less, resulting in a cumulative light intensity of 50 mJ / cm². 2 It is irradiated with ultraviolet light in a certain way to form an anti-glare layer with a thickness of 4.8μm.

[0337] Next, the following low-refractive-index coating solution is applied to the anti-glare layer. Then, it is dried at 50°C and a wind speed of 20 m / s for 30 seconds. Next, it is dried in a nitrogen atmosphere with an oxygen concentration of less than 200 ppm until the cumulative light intensity reaches 150 mJ / cm². 2 The optical film of Example 1 is obtained by irradiating the film with ultraviolet light to form a low-refractive-index layer with a thickness of 0.10 μm. The refractive index of the low-refractive-index layer is 1.31.

[0338] The anti-glare layers of Examples 1-6 and Comparative Examples 1-5 were produced by the method described in (d1) in the main text of the instruction manual.

[0339] <Anti-glare coating liquid 1>

[0340] · 70 parts of polyurethane acrylate A

[0341] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0342] · Polyurethane acrylate B 20 parts

[0343] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0344] 10 parts pentaerythritol triacrylate

[0345] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0346] · 25 parts of silica particles

[0347] (Surface treated amorphous silica, d10: 1.4μm, d50: 3.5μm, d90: 6.3μm)

[0348] · 10 parts organic granules A

[0349] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.515)

[0350] • 4.1 parts of photopolymerization initiator

[0351] (IGM Resins BV, product name: Omnirad 184)

[0352] • 0.8 parts of photopolymerization initiator

[0353] (IGM Resins BV, product name: Omnirad 907)

[0354] • 0.1 parts of silicone-based leveling agent

[0355] (Momentive Performance Materials, product name: TSF 4460)

[0356] Solvent (toluene) 182.4 parts

[0357] • Solvent (cyclohexanone) 1.7 parts

[0358] • Solvent (methyl isobutyl ketone) 44.4 parts

[0359] <Low Refractive Index Coating Solution>

[0360] · 100 parts of multifunctional acrylate composition

[0361] (Made by Daiichi Kogyo Pharmaceutical Co., Ltd., trade name "New Frontier MF-001")

[0362] · 0.5 parts of acrylic polymer

[0363] (Weight-average molecular weight: 50,000)

[0364] · 200 parts of hollow silica particles

[0365] (Particles with an average primary particle size of 75 nm, surface-treated with a silane coupling agent containing methacrylyl groups)

[0366] 50 parts of solid silica granules

[0367] (Particles with an average primary particle size of 12.5 nm, surface-treated with a silane coupling agent containing methacrylamide groups)

[0368] · 15 parts of silicone-based leveling agent

[0369] (Shin-Etsu Chemical Co., Ltd., trade name "X-22-164E")

[0370] • 4.3 parts of photopolymerization initiator

[0371] (IGM Resins, product name "Omnirad127")

[0372] · 14,867 parts of solvent

[0373] (Mixed solvent of methyl isobutyl ketone and 1-methoxy-2-propyl acetate. Mass ratio = 72 / 28)

[0374] [Examples 2-6]

[0375] Except for changing the anti-glare coating liquid 1 to the anti-glare coating liquids 2 to 6 described below, the optical films of Examples 2 to 6 were obtained in the same manner as in Example 1.

[0376] [Example 7]

[0377] The anti-glare coating liquid 7 of the following formulation was applied to a transparent substrate (80 μm thick triacetyl cellulose resin film (TAC), Fujifilm Corporation, TD80UL) and dried at 70°C and a wind speed of 1 m / s for 60 seconds. The cumulative light intensity was then measured to be 60 mJ / cm². 2 The film is irradiated in a manner similar to that in Example 1 to form an anti-glare layer. The thickness of the anti-glare layer is 9.0 μm. Next, a low refractive index layer is formed on the anti-glare layer in the same manner as in Example 1 to obtain the optical film of Example 7.

[0378] The anti-glare layer in Example 7 was produced by the phase separation method described in (d2) in the main text of the specification.

[0379] [Comparative Example 1]

[0380] The anti-glare coating liquid 1 was changed to the anti-glare coating liquid 8 described below, and the thickness of the anti-glare layer was changed to 2.0 μm. Otherwise, the optical film of Comparative Example 1 was obtained by operating in the same manner as in Example 1.

[0381] [Comparative Examples 2-4]

[0382] Except for changing the anti-glare coating liquid 1 to the anti-glare coating liquids 9 to 11 described below, the optical films of Comparative Examples 2 to 4 were obtained in the same manner as in Example 1.

[0383] [Comparative Example 5]

[0384] The anti-glare coating liquid 1 was changed to the anti-glare coating liquid 12 described below, and the thickness of the anti-glare layer was changed to 5.2 μm. Otherwise, the optical film of Comparative Example 5 was obtained by operating in the same manner as in Example 1.

[0385] <Anti-glare coating liquid 2>

[0386] · 70 parts of polyurethane acrylate A

[0387] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0388] · Polyurethane acrylate B 20 parts

[0389] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0390] 10 parts pentaerythritol triacrylate

[0391] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0392] · 23 parts of silica particles

[0393] (Surface treated amorphous silica, d10: 1.4μm, d50: 3.5μm, d90: 6.3μm)

[0394] Organic granules A 5.8 parts

[0395] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.515)

[0396] Organic granules B 4.3 parts

[0397] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.590)

[0398] • 4.1 parts of photopolymerization initiator

[0399] (IGM Resins BV, product name: Omnirad 184)

[0400] • 0.7 parts of photopolymerization initiator

[0401] (IGM Resins BV, product name: Omnirad 907)

[0402] • 0.1 parts of silicone-based leveling agent

[0403] (Momentive Performance Materials, product name: TSF 4460)

[0404] Solvent (toluene) 201.2 parts

[0405] • Solvent (cyclohexanone) 1.7 parts

[0406] • Solvent (methyl isobutyl ketone) 21.9 parts

[0407] <Anti-glare coating liquid 3>

[0408] · 70 parts of polyurethane acrylate A

[0409] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0410] · Polyurethane acrylate B 20 parts

[0411] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0412] 10 parts pentaerythritol triacrylate

[0413] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0414] · 23 parts of silica particles

[0415] (Surface treated amorphous silica, d10: 1.4μm, d50: 3.5μm, d90: 6.3μm)

[0416] Organic granules A, 4.1 parts

[0417] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.515)

[0418] Organic Granules B 5.9 parts

[0419] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.590)

[0420] • 4.1 parts of photopolymerization initiator

[0421] (IGM Resins BV, product name: Omnirad 184)

[0422] • 0.7 parts of photopolymerization initiator

[0423] (IGM Resins BV, product name: Omnirad 907)

[0424] • 0.1 parts of silicone-based leveling agent

[0425] (Momentive Performance Materials, product name: TSF 4460)

[0426] Solvent (toluene) 201.2 parts

[0427] • Solvent (cyclohexanone) 1.7 parts

[0428] • Solvent (methyl isobutyl ketone) 21.9 parts

[0429] <Anti-glare coating liquid 4>

[0430] · 70 parts of polyurethane acrylate A

[0431] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0432] · Polyurethane acrylate B 20 parts

[0433] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0434] 10 parts pentaerythritol triacrylate

[0435] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0436] · 21 parts of silica particles

[0437] (Surface treated amorphous silica, d10: 1.4μm, d50: 3.5μm, d90: 6.3μm)

[0438] Organic granules A, 4.1 parts

[0439] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.515)

[0440] Organic Granules B 5.9 parts

[0441] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.590)

[0442] · 3.8 parts of photopolymerization initiator

[0443] (IGM Resins BV, product name: Omnirad 184)

[0444] • 0.7 parts of photopolymerization initiator

[0445] (IGM Resins BV, product name: Omnirad 907)

[0446] • 0.2 parts of silicone-based leveling agent

[0447] (Momentive Performance Materials, product name: TSF 4460)

[0448] Solvent (toluene) 198.0 parts

[0449] • Solvent (cyclohexanone) 1.7 parts

[0450] • Solvent (methyl isobutyl ketone) 21.9 parts

[0451] <Anti-glare coating liquid 5>

[0452] · 70 parts of polyurethane acrylate A

[0453] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0454] · Polyurethane acrylate B 20 parts

[0455] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0456] 10 parts pentaerythritol triacrylate

[0457] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0458] · 19 parts of silica particles

[0459] (Surface treated amorphous silica, d10: 1.4μm, d50: 3.5μm, d90: 6.3μm)

[0460] Organic granules B12 parts

[0461] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.590)

[0462] • 3.7 parts of photopolymerization initiator

[0463] (IGM Resins BV, product name: Omnirad 184)

[0464] • 0.6 parts of photopolymerization initiator

[0465] (IGM Resins BV, product name: Omnirad 907)

[0466] • 0.2 parts of silicone-based leveling agent

[0467] (Momentive Performance Materials, product name: TSF 4460)

[0468] Solvent (toluene) 224.9 parts

[0469] • Solvent (cyclohexanone) 2.0 parts

[0470] • Solvent (methyl isobutyl ketone) 24.7 parts

[0471] <Anti-glare coating liquid 6>

[0472] · Polyurethane acrylate A 70 parts

[0473] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0474] · Polyurethane acrylate B 20 parts

[0475] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0476] 10 parts pentaerythritol triacrylate

[0477] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0478] · 19 parts of silica particles

[0479] (Surface treated amorphous silica, d10: 1.4μm, d50: 3.5μm, d90: 6.3μm)

[0480] Organic Granules A, 11 parts

[0481] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.515)

[0482] Organic Granules (B1 portion)

[0483] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.590)

[0484] • 3.7 parts of photopolymerization initiator

[0485] (IGM Resins BV, product name: Omnirad 184)

[0486] • 0.6 parts of photopolymerization initiator

[0487] (IGM Resins BV, product name: Omnirad 907)

[0488] • 0.2 parts of silicone-based leveling agent

[0489] (Momentive Performance Materials, product name: TSF 4460)

[0490] Solvent (toluene) 197.4 parts

[0491] • Solvent (cyclohexanone) 2.0 parts

[0492] • Solvent (methyl isobutyl ketone) 21.6 parts

[0493] <Anti-glare coating liquid 7>

[0494] • 5.0 parts of oligomer containing isoborneol methacrylate

[0495] 60 parts of pentaerythritol triacrylate

[0496] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0497] · 60 parts of inorganic microparticle dispersion

[0498] (Nissan Chemical Co., Ltd., silica with reactive functional groups introduced onto the surface, solvent: MIBK, solid content: 35.5%)

[0499] · 3 parts of photopolymerization initiator

[0500] (IGM Resins BV, product name: Omnirad 184)

[0501] · 1 part photopolymerization initiator

[0502] (IGM Resins BV, product name: Omnirad 907)

[0503] Solvent (isopropanol) 115 parts

[0504] <Anti-glare coating liquid 8>

[0505] 100 parts pentaerythritol triacrylate

[0506] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0507] · 11 parts of silica particles

[0508] (Surface treated amorphous silica, d10: 2.2μm, d50: 4.0μm, d90: 6.8μm)

[0509] • 5.7 parts of photopolymerization initiator

[0510] (IGM Resins BV, product name: Omnirad 184)

[0511] • 1.4 parts of photopolymerization initiator

[0512] (IGM Resins BV, product name: Omnirad 907)

[0513] • 0.3 parts of silicone-based leveling agent

[0514] (Momentive Performance Materials, product name: TSF 4460)

[0515] Solvent (toluene) 180.1 parts

[0516] • Solvent (methyl isobutyl ketone) 20.3 parts

[0517] <Anti-glare coating liquid 9>

[0518] · 18 parts of EO-modified triacrylate isocyanuric acid

[0519] (Dong-A Synthetic Co., Ltd., Trade Name: M-313)

[0520] 82 parts of pentaerythritol triacrylate

[0521] (Made by Nippon Kayaku Co., Ltd., KAYARAD-PET-30)

[0522] Organic granules C11 parts

[0523] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 3.5 μm (more than 90% of the particles have a size of 3.3–3.7 μm) and a refractive index of 1.545)

[0524] · 120 parts of inorganic ultrafine particles

[0525] (Silica with reactive functional groups is introduced onto the surface, the solvent is MIBK, and the solid content is 30%)

[0526] (Average primary particle size is 12nm)

[0527] • 3.5 parts of photopolymerization initiator

[0528] (IGM Resins BV, product name: Omnirad 184)

[0529] • 0.8 parts of photopolymerization initiator

[0530] (IGM Resins BV, product name: Omnirad 907)

[0531] • 0.1 parts of silicone-based leveling agent

[0532] (Momentive Performance Materials, product name: TSF 4460)

[0533] Solvent (toluene) 132.4 parts

[0534] • Solvent (cyclohexanone) 2.0 parts

[0535] Solvent (isopropanol) 51 parts

[0536] <Anti-glare coating liquid 10>

[0537] · 70 parts of polyurethane acrylate A

[0538] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0539] · Polyurethane acrylate B 20 parts

[0540] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0541] 10 parts pentaerythritol triacrylate

[0542] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0543] · 26 parts of silica particles

[0544] (Surface treated amorphous silica, d10: 1.3μm, d50: 2.8μm, d90: 4.8μm)

[0545] Organic granules A, 4.1 parts

[0546] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.515)

[0547] Organic Granules B 5.9 parts

[0548] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.590)

[0549] • 4.2 parts of photopolymerization initiator

[0550] (IGM Resins BV, product name: Omnirad 184)

[0551] • 0.8 parts of photopolymerization initiator

[0552] (IGM Resins BV, product name: Omnirad 907)

[0553] • 0.2 parts of silicone-based leveling agent

[0554] (Momentive Performance Materials, product name: TSF 4460)

[0555] Solvent (toluene) 206.2 parts

[0556] • Solvent (cyclohexanone) 1.7 parts

[0557] • Solvent (methyl isobutyl ketone) 22.3 parts

[0558] <Anti-glare coating liquid 11>

[0559] · 70 parts of polyurethane acrylate A

[0560] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0561] · Polyurethane acrylate B 20 parts

[0562] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0563] 10 parts pentaerythritol triacrylate

[0564] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0565] · 11.9 parts of silica particles

[0566] (Surface treated amorphous silica, d10: 1.3μm, d50: 2.8μm, d90: 4.8μm)

[0567] Organic Granules A, 4 parts

[0568] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.515)

[0569] Organic Granules B, 6 parts

[0570] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 1.5 μm (more than 90% of the particles have a size of 1.3–1.7 μm) and a refractive index of 1.590)

[0571] · 3 parts of photopolymerization initiator

[0572] (IGM Resins BV, product name: Omnirad 184)

[0573] • 0.3 parts of photopolymerization initiator

[0574] (IGM Resins BV, product name: Omnirad 907)

[0575] • 0.3 parts of silicone-based leveling agent

[0576] (Momentive Performance Materials, product name: TSF 4460)

[0577] Solvent (toluene) 183.4 parts

[0578] • Solvent (cyclohexanone) 1.7 parts

[0579] • Solvent (methyl isobutyl ketone) 20.2 parts

[0580] <Anti-glare coating liquid 12>

[0581] · 70 parts of polyurethane acrylate A

[0582] (New Nakamura Chemical Industry Co., Ltd., Trade Name: U-1100H, Molecular Weight: 800, Functional Groups: 6)

[0583] · Polyurethane acrylate B 20 parts

[0584] (New Nakamura Chemical Industry Co., Ltd., trade name: U-15HA, molecular weight 2300, number of functional groups 15)

[0585] 10 parts pentaerythritol triacrylate

[0586] (Dong-A Synthetic Co., Ltd., Trade Name: M-305)

[0587] · 10 parts of silica particles

[0588] (Surface treated amorphous silica, d10: 0.9μm, d50: 1.9μm, d90: 3.1μm)

[0589] Organic granules D 44 parts

[0590] (Spherical polyacrylic acid-styrene copolymer, with an average particle size of 2.0 μm (more than 90% of which are 1.8–2.2 μm in size) and a refractive index of 1.515)

[0591] · 4 parts of photopolymerization initiator

[0592] (IGM Resins BV, product name: Omnirad 184)

[0593] • 0.8 parts of photopolymerization initiator

[0594] (IGM Resins BV, product name: Omnirad 907)

[0595] • 0.3 parts of silicone-based leveling agent

[0596] (Momentive Performance Materials, product name: TSF 4460)

[0597] Solvent (toluene) 224.4 parts

[0598] • Solvent (cyclohexanone) 41.7 parts

[0599] In the anti-glare coating liquids 1 to 12, polyurethane acrylates A to B are all polyurethane acrylate oligomers.

[0600] [Table 1]

[0601] Table 1

[0602]

[0603] [Table 2]

[0604] Table 2

[0605]

[0606] The results in Table 1 confirm that the optical film of the embodiment has excellent anti-glare and scratch resistance.

[0607] Regarding the optical films of Comparative Examples 1 and 2, due to their smaller Sdr, they cannot meet the anti-glare requirements in the tilt direction. Regarding the optical film of Comparative Example 3, due to its larger Sdr, it cannot meet the scratch resistance requirements. Regarding the optical film of Comparative Example 4, due to its larger Sal, it cannot meet the anti-glare requirements in the tilt direction. Regarding the optical film of Comparative Example 5, due to its smaller Sal, it cannot meet both scratch resistance and anti-glare requirements in the tilt direction.

[0608] Label Explanation

[0609] 10: Substrate

[0610] 20: Functional Layer

[0611] 21: Anti-glare layer

[0612] 22: Anti-reflective layer

[0613] 100: Optical film

[0614] 110: Display element

[0615] 120: Image display panel

Claims

1. An optical film, wherein, The optical film has an uneven surface. Regarding the aforementioned uneven surface, the unfolded area ratio Sdr of the interface as specified in ISO 25178-2:2012 is 0.010 or more and 0.060 or less, and the minimum autocorrelation length Sal as specified in ISO 25178-2:2012 is 4.0 μm or more and 12.0 μm or less. Regarding the uneven surface, the pole height Sxp, as specified in ISO 25178-2:2012, is greater than 0.50 μm and less than 2.00 μm, wherein the pole height Sxp refers to the difference between the height with a load area ratio of 2.5% and the height with a load area ratio of 50%.

2. The optical film according to claim 1, wherein, Regarding the aforementioned uneven surface, the arithmetic mean height Sa, as specified in ISO 25178-2:2012, is greater than 0.20 μm and less than 1.00 μm.

3. The optical film according to claim 1, wherein, The optical film has a functional layer on the substrate, and the surface of the functional layer is the uneven surface.

4. The optical film according to claim 3, wherein, The optical film includes an anti-glare layer as the functional layer, and the surface of the anti-glare layer is the uneven surface.

5. The optical film according to claim 3, wherein, The optical film includes an anti-glare layer and an anti-reflection layer as the functional layers, and the surface of the anti-reflection layer is the uneven surface.

6. The optical film according to claim 4 or 5, wherein, The anti-glare layer comprises adhesive resin and particles.

7. The optical film according to claim 6, wherein, The optical film comprises amorphous inorganic particles as the particles.

8. The optical film according to claim 7, wherein, The optical film also contains organic particles as said particles.

9. The optical film according to claim 6, wherein, The adhesive resin comprises a cured product of an ionizing radiation-curing resin composition.

10. The optical film according to claim 1 or 2, wherein, JIS K7136:2000 specifies a haze level of 20% or higher and 75% or lower.

11. The optical film according to claim 1 or 2, wherein, The uneven surface is located on the outermost surface of the optical film.

12. An image display panel, wherein, The image display panel is configured on a display element such that the surface of the optical film as described in claim 1 or 2 faces the opposite side to the display element, and the optical film is disposed on the outermost surface.

13. An image display device, wherein, The image display device includes the image display panel as described in claim 12.

Images