Anti-glare film

Abstract

This anti-glare film comprises: a substrate film that is a biaxially stretched film which satisfies the relationship shown in formula 1 and which has an in-plane birefringence; and an anti-glare layer disposed so as to overlap the substrate film. A surface of the anti-glare layer on the side thereof opposite the substrate film has a relief pattern in which: a fractal parameter Safc is a value of 0.02 or more when the cutoff value λs of a short wavelength is set to 50 μm; and a value Smr1 is 14% or more when the cutoff value λc of a long wavelength is set to 25 μm and the cutoff value λs of the short wavelength is set to 2.6 μm. Formula 1: substrate film thickness D(m) × retardation Re (m) ≥ 1.0 × 10 - 10 (m2).

Description

Anti-glare film

[0001] The present disclosure relates to an antiglare film to be attached to a display device, a polarizing plate, or the like.

[0002] Antiglare films are attached to various display devices and polarizing plates. For example, antiglare films scatter incident light from the outside and protect the surface on which the antiglare film is attached from the outside. Antiglare films include a substrate film and an antiglare layer disposed on the substrate film. The antiglare layer has a roughened surface formed with fine irregularities. Patent Document 1 describes an antiglare film using a biaxially stretched polyethylene terephthalate (hereinafter also referred to as PET) film as the substrate film.

[0003] JP 2009-156938 A Japanese Patent No. 5051328 A

[0004] Anti-glare films using biaxially stretched films, such as the anti-glare film of Patent Document 1, have sufficient mechanical strength, but may suffer from unwanted rainbow unevenness (also referred to as color unevenness or interference unevenness) due to the influence of retardation. Patent Document 2 describes a method of preventing rainbow unevenness by using a polyester film whose anisotropy is enhanced by different degrees of stretching in each stretching direction. However, in this case, the degree of stretching is insufficient compared to that of a normal biaxially stretched film, resulting in a decrease in the mechanical strength of the anti-glare film. Furthermore, additional processing or equipment is required to adjust the degrees of stretching in each stretching direction to be different, which increases production costs.

[0005] Therefore, an object of the present disclosure is to provide an antiglare film that has sufficient mechanical strength and can suppress rainbow unevenness at low cost.

[0006] An antiglare film according to one embodiment of the present disclosure comprises a substrate film which is a biaxially stretched film having in-plane birefringence and which satisfies the relationship shown in Formula 1, and an antiglare layer disposed on the substrate film, wherein the surface of the antiglare layer opposite to the substrate film has an uneven shape in which the fractal parameter Safc is a value in the range of 0.02 or more when the short wavelength cutoff value λs is set to 50 μm, and the fractal parameter Smr1 is a value in the range of 14% or more when the long wavelength cutoff value λc is set to 25 μm and the short wavelength cutoff value λs is set to 2.6 μm. [Formula 1] Substrate film thickness D (m) × retardation Re (m) ≧ 1.0 × 10 －１０ (m ２ )

[0007] According to the above-described aspects of the present disclosure, an antiglare film that has sufficient mechanical strength and can suppress rainbow unevenness can be provided at low cost.

[0008] FIG. 1 is a cross-sectional view of a display device according to a first embodiment. FIG. 2 is an enlarged cross-sectional view of the surface of the anti-glare layer of the anti-glare film of FIG. 1. FIG. 3 is an enlarged cross-sectional view of the surface of the anti-glare layer of an anti-glare film according to a second embodiment. FIG. 4 is a partial cross-sectional view of an anti-glare film having an anti-reflection layer of a first structure according to a third embodiment. FIG. 5 is a partial cross-sectional view of an anti-glare film having an anti-reflection layer of a second structure according to a third embodiment. FIG. 6 is a partial cross-sectional view of an anti-glare film having an anti-reflection layer of a third structure according to a third embodiment. FIG. 7 is a cross-sectional view of an optical member according to a fourth embodiment. FIG. 8 is a cross-sectional view of a display device according to a fifth embodiment.

[0009] Through investigations by the present inventors, it has been confirmed that, in an antiglare film, when the thickness D of the substrate film and the integrated value (D×Re) of the retardation Re are set to values ​​equal to or greater than a predetermined range, and the Safc value and Smr1 value of the uneven shape on the surface of the antiglare layer opposite to the substrate film side are set to values ​​within predetermined ranges, by using a biaxially stretched film as the substrate film, it is possible to obtain excellent antiglare effect and rainbow unevenness prevention effect while maintaining sufficient mechanical strength of the antiglare film. The antiglare film of the present disclosure has been made based on this finding.

[0010] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. The cutoff value referred to in this specification refers to a predetermined wavelength that is removed from a profile curve, as defined in accordance with JIS B 0601:2001. Furthermore, glare refers to a phenomenon defined in JIS C 1006:2019.

[0011] (First embodiment) [Anti-glare film and display device] Fig. 1 is a cross-sectional view of a display device 1 according to the first embodiment. Fig. 2 is an enlarged cross-sectional view of the surface 4a of the anti-glare layer 4 of the anti-glare film 2 of Fig. 1. As shown in Fig. 1, the display device 1 includes a display element 16 and an anti-glare film 2. As an example, the anti-glare film 2 is attached to the display surface 16a of the display element 16. The anti-glare film 2 has multiple functions. The anti-glare film 2 scatters incident light that is incident on the display surface 16a to provide anti-glare. The anti-glare film 2 also protects the display surface 16a from the outside.

[0012] There is no limitation on the type of the display element 16. For example, the display element 16 includes a display such as a liquid crystal display (LCD), an organic light-emitting diode (OLED), an inorganic light-emitting diode (EL) display, or a plasma display panel (PDP). Examples of the display device 1 include a personal computer (PC), a monitor, a television, and a smartphone.

[0013] The anti-glare film 2 comprises a substrate film 3, an anti-glare layer 4, and an adhesive layer 5. The adhesive layer 5 contains a material that is unlikely to affect the optical properties of the anti-glare film 2, such as an optical adhesive. Another layer may be disposed between the substrate film 3 and the anti-glare layer 4. The substrate film 3 is disposed so as to cover the display surface 16a and supports the anti-glare layer 4. The substrate film 3 of this embodiment covers the entire display surface 16a. The substrate film 3 is a biaxially stretched film that satisfies the relationship shown in the following formula 1 and has an in-plane birefringence. [Formula 1] Substrate film thickness D (m) × retardation Re (m) ≥ 1.0 × 10 －１０ (m ２ )

[0014] The retardation Re refers to a birefringence phase difference. That is, the retardation Re is calculated by the following formula 2 based on the refractive index (nx) in the direction (slow axis direction) with the largest refractive index in the plane of the base film 3, the refractive index (ny) in the direction (fast axis direction) perpendicular to the slow axis direction, and the thickness D of the base film 3. [Formula 2] Retardation Re (m) = (nx - ny) × base film thickness D (m)

[0015] As an example, the substrate film thickness D×retardation Re (hereinafter also simply referred to as “integrated value (D×Re)”) is 1.5×10 －１０ (m ２ ) or more is more preferable, and 2.0 × 10 －１０ (m ２ ) or more is more preferable. By setting the integrated value (D × Re) to a value equal to or greater than the lower limit value shown in Formula 1, it is possible to prevent, for example, the problem that rainbow unevenness becomes too strong and cannot be suppressed by the scattering of transmitted light due to the uneven surface shape of the antiglare layer alone. The upper limit value of the integrated value (D × Re) is not particularly limited, but is preferably 6.0 × 10 －１０ (m ２ ), 5.0 x 10 －１０ (m ２ ), or 4.0 × 10 －１０ (m ２ ) can be exemplified. In the case of the antiglare film 2, the integrated value is 1.0 × 10 －１０ (m ２ ) or more, and as described below, the surface 4a of the antiglare layer 4 opposite the substrate film 3 has an uneven shape in which the fractal parameter Safc is a value in the range of 0.02 or more when the short wavelength cutoff value λs is set to 50 μm, and Smr1 is a value in the range of 14% or more when the long wavelength cutoff value λc is set to 25 μm and the short wavelength cutoff value λs is set to 2.6 μm, thereby appropriately suppressing rainbow unevenness. As an example, the substrate film 3 has a retardation Re in the range of 1000 nm or more and 4000 nm or less. The value of the retardation Re of the substrate film 3 is not limited to this.

[0016] Unlike the film of Patent Document 2, for example, the biaxially stretched substrate film 3 is sufficiently stretched in the slow axis direction and the fast axis direction during production. Therefore, for example, because the degree of stretching is lower in one of the two directions than in the other, damage such as cracking is less likely to occur in the substrate film 3 when an external force is applied. This results in good mechanical strength for the substrate film 3. Specifically, for example, the difference in breaking strength (MPa) between the slow axis direction and the fast axis direction of the substrate film 3 is suppressed to a value within a range of less than 30%. Furthermore, for example, the difference in breaking elongation (%) between the slow axis direction and the fast axis direction of the substrate film 3 is suppressed to a value within a range of less than 60%. The terms "breaking strength" and "breaking elongation" used herein refer to values ​​measured using methods conforming to JIS-C-2151:2019 and ASTM-D-882.

[0017] The antiglare layer 4 is disposed on the substrate film 3. As shown in FIG. 2 , the surface 4a of the antiglare layer 4 opposite the substrate film 3 has a predetermined uneven shape. For example, the surface 4a of the antiglare layer 4 is exposed to the outside. The antiglare layer 4 imparts antiglare properties to the antiglare film 2 and scatters and reflects incident light from the outside to prevent unwanted reflections on the display surface 16a. The antiglare layer 4 also functions as a hard coat (HC) layer that protects the display surface 16a. The surface 4a of the antiglare layer 4 has an uneven shape in which the fractal parameter Safc is 0.02 or greater when the short wavelength cutoff value λs is set to 50 μm, and the Smr1 is 14% or greater when the long wavelength cutoff value λc is set to 25 μm and the short wavelength cutoff value λs is set to 2.6 μm.

[0018] Here, Safc (Areal Fractal Complexity) is a parameter described in Section 4.4.9.5 of ISO 25178-2:2012, an international standard for surface roughness. Safc is equal to -1000 times the slope of the approximate line when the relationship between specific surface area and scale is plotted on a double logarithmic graph, and is related to the fractal dimension. The larger Safc (in other words, the steeper the slope of the approximate line), the larger the fractal dimension, and the more complex the surface shape is evaluated to be.

[0019] By setting the short wavelength cutoff value λs at 50 μm when measuring Safc, for example, unevenness that does not affect rainbow unevenness on the surface 4a of the anti-glare layer 4 can be removed. Furthermore, for example, the higher the Safc value when the short wavelength cutoff value λs is set to 50 μm, the more self-similar and finer the unevenness on the surface 4a of the anti-glare layer 4 becomes. This allows the surface 4a of the anti-glare layer 4 to scatter transmitted light, making it easier to suppress rainbow unevenness. Safc is preferably, for example, in the range of 0.02 to 1.00, and more preferably in the range of 0.03 to 0.50. The upper limit of Safc can be set as appropriate. Furthermore, for example, by setting the upper limit of Safc to 1.00, even small characters displayed on the display surface 16a to which the anti-glare film 2 is attached can be made more visible.

[0020] Smr1 is a functional parameter described in ISO25178-2:2012. In a graph showing a load curve, the line with the smallest slope among the lines where the difference in areal load ratio Smr values ​​at two points at a certain height is 40% is defined as an equivalent line. When the difference in height of this equivalent line when the areal load ratio is 0% and 100% is defined as a core portion Sk, the areal load ratio (%) that separates the core portion from protruding peaks that are equal to or higher than the height of the core portion is defined as Smr1.

[0021] By setting the long wavelength cutoff value λc at 25 μm when measuring Smr1, for example, large irregularities that do not affect rainbow unevenness on the surface 4a of the anti-glare layer 4 can be removed. Furthermore, for example, the higher the value of Smr1 when the long wavelength cutoff value λc is set to 25 μm, the more transmitted light is scattered on the surface 4a of the anti-glare layer 4, making it easier to suppress rainbow unevenness. Smr1 is preferably, for example, in the range of 14% to 50%, and more preferably in the range of 15% to 30%. The upper limit of Smr1 can be set appropriately. For example, by setting the upper limit of Smr1 to 50%, the ratio of convex portions in the irregularities on the surface 4a of the anti-glare layer 4 can be suppressed, making it easier to maintain the mechanical strength of the anti-glare film 2.

[0022] According to the antiglare film 2 having the above configuration, the uneven shape of the surface 4a of the antiglare layer 4 is set to the above-mentioned values ​​of Safc and Smr1, so that the uneven shape is formed to have a distribution structure of steep unevenness with a high number density. This scatters light incident on the surface 4a of the antiglare layer 4, and appropriately suppresses reflection of external light on the surface 4a of the antiglare layer 4. Therefore, deterioration of the image display performance of the display device 1 is suppressed.

[0023] Furthermore, by constructing the antiglare film 2 so as to include an antiglare layer 4 having the uneven surface 4a and a substrate film 3 that satisfies formula 1, the substrate film 3 is made of a biaxially stretched film, maintaining sufficient mechanical strength, and the antiglare film 2 that exhibits excellent antiglare effect and rainbow unevenness prevention effect can be realized at low cost.

[0024] [Configuration Example of Base Film] The base film 3 contains a resin material. Examples of the resin material of the base film 3 include a transparent polymer. Specific examples of resin materials for the base film 3 include cellulose derivatives (cellulose acetates such as cellulose triacetate (TAC) and cellulose diacetate), polyester resins (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyarylate resins, etc.), polysulfone resins (polysulfone, polyethersulfone (PES), etc.), polyetherketone resins (polyetherketone (PEK), polyetheretherketone (PEEK), etc.), polycarbonate resins (PC), polyolefin resins (polyethylene, polypropylene, etc.), cyclic polyolefin resins (such as ARTON (registered trademark) film manufactured by JSR Corporation and ZEONEX (registered trademark) film manufactured by Zeon Corporation), halogen-containing resins (such as polyvinylidene chloride), (meth)acrylic resins, styrene resins (such as polystyrene), and vinyl acetate or vinyl alcohol resins (such as polyvinyl alcohol (PVA)).

[0025] The thickness D of the base film 3 can be appropriately set within a range that satisfies Formula 1. The thickness D of the base film 3 is preferably, for example, from 20 μm to 500 μm, more preferably from 50 μm to 200 μm, and even more preferably from 75 μm to 150 μm.

[0026] [Example of Antiglare Layer Configuration] The antiglare layer 4 of the first embodiment contains multiple resin components and has a phase-separated structure of the multiple resin components. As an example, the antiglare layer 4 has a surface 4a on which multiple convex portions are dispersed. As a result, the surface 4a of the antiglare layer 4 of this embodiment has a sea-island structure formed by the multiple convex portions and the concave portions between them. The antiglare layer 4 exhibits antiglare properties due to the uneven shape formed by the multiple convex portions and the concave portions between them. By including such an antiglare layer 4, the antiglare film 2 has an excellent balance between the haze value and the transmitted image clarity (image clarity). The surface 4a of the antiglare layer 4 may have a co-continuous phase structure in which the multiple convex portions are densely arranged.

[0027] Furthermore, the anti-glare film 2 prevents light from the display surface 16a that passes through the anti-glare layer 4 from being refracted by the unevenness of the surface of the anti-glare layer 4, and prevents the pixels of the display surface 16a from appearing enlarged due to the lens effect caused by the uneven shape of the surface 4a of the anti-glare layer 4, thereby suppressing glare on the display surface 16a. As a result, even when the anti-glare film 2 is attached to a display surface 16a having high-definition pixels, glare on the display surface 16a can be suppressed to a high degree while maintaining anti-glare properties, and blurring of characters and images can also be suppressed.

[0028] As will be described later, the phase-separated structure of the antiglare layer 4 is formed by spinodal decomposition (wet spinodal decomposition) from a liquid phase using a solution of materials for the antiglare layer 4. For details of the antiglare layer 4, see, for example, the description in Japanese Patent Application No. 2012-231496.

[0029] Examples of the polymer contained in the antiglare layer 4 include thermoplastic resins. Examples of thermoplastic resins include styrene-based resins, (meth)acrylic-based resins, organic acid vinyl ester-based resins, vinyl ether-based resins, halogen-containing resins, olefin-based resins (including alicyclic olefin-based resins), polycarbonate-based resins, polyester-based resins, polyamide-based resins, thermoplastic polyurethane resins, polysulfone-based resins (polyethersulfone, polysulfone, etc.), polyphenylene ether-based resins (2,6-xylenol polymers, etc.), cellulose derivatives (cellulose esters, cellulose carbamates, cellulose ethers, etc.), silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubbers or elastomers (diene-based rubbers such as polybutadiene and polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic rubbers, urethane rubbers, silicone rubbers, etc.). These thermoplastic resins can be used alone or in combination of two or more.

[0030] Further, examples of the polymer include those having a functional group that participates in a curing reaction or a functional group that reacts with a curable compound. The polymer may have the functional group in the main chain or a side chain.

[0031] The functional group may be a condensable group or a reactive group (for example, a hydroxyl group, an acid anhydride group, a carboxyl group, an amino group or an imino group, an epoxy group, a glycidyl group, or an isocyanate group), a polymerizable group (for example, a C group such as a vinyl group, a propenyl group, an isopropenyl group, a butenyl group, or an allyl group), or ２－６ C such as alkenyl group, ethynyl, propynyl, butynyl group ２－６ C such as alkynyl group, vinylidene group ２－６ Examples of such functional groups include alkenylidene groups and groups having such polymerizable groups (e.g., (meth)acryloyl groups). Of these functional groups, polymerizable groups are preferred.

[0032] The antiglare layer 4 may contain multiple types of polymers. These polymers may be phase-separable by spinodal decomposition from a liquid phase, or may be incompatible with each other. The combination of the first polymer and the second polymer contained in the multiple types of polymers is not particularly limited, but polymers that are incompatible with each other near the processing temperature can be used.

[0033] For example, when the first polymer is a styrene-based resin (polystyrene, styrene-acrylonitrile copolymer, etc.), the second polymer may be a cellulose derivative (for example, a cellulose ester such as cellulose acetate propionate), a (meth)acrylic resin (polymethyl methacrylate, etc.), an alicyclic olefin-based resin (a polymer having norbornene as a monomer, etc.), a polycarbonate-based resin, a polyester-based resin (polyC ２－４ alkylene arylate copolyesters, etc.) can be exemplified.

[0034] Furthermore, for example, when the first polymer is a cellulose derivative (for example, a cellulose ester such as cellulose acetate propionate), the second polymer may be a styrene-based resin (such as polystyrene or a styrene-acrylonitrile copolymer), a (meth)acrylic-based resin, an alicyclic olefin-based resin (such as a polymer having norbornene as a monomer), a polycarbonate-based resin, or a polyester-based resin (polyC ２－４ alkylene arylate copolyesters, etc.) can be exemplified.

[0035] The plurality of types of polymers include at least cellulose esters (e.g., cellulose C such as cellulose diacetate, cellulose triacetate, cellulose acetate propionate, and cellulose acetate butyrate). ２－４ alkyl carboxylic acid esters) may be included.

[0036] Here, the phase-separated structure of the antiglare layer 4 is fixed by curing a precursor of a curable resin contained in the plurality of resin components with active energy rays (ultraviolet rays, electron beams, etc.), heat, etc. during the production of the antiglare layer 4. Furthermore, such a curable resin imparts scratch resistance and durability to the antiglare layer 4.

[0037] From the viewpoint of obtaining scratch resistance in the antiglare layer 4, it is desirable that at least one of the polymers included in the plurality of types of polymers is a polymer having a functional group in its side chain that can react with the curable resin precursor. The polymer forming the phase-separated structure may include a thermoplastic resin or other polymers in addition to the two mutually incompatible polymers described above. The weight ratio M1 / M2 of the weight M1 of the first polymer to the weight M2 of the second polymer, and the glass transition temperatures of the polymers, can be set as appropriate.

[0038] Examples of the curable resin precursor include a curable compound that has a functional group that reacts with active energy rays (ultraviolet rays, electron beams, etc.), heat, etc., and that is cured or crosslinked by this functional group to form a resin (particularly a cured resin or a crosslinked resin).

[0039] Examples of such compounds include thermosetting compounds or thermosetting resins (low molecular weight compounds having an epoxy group, a polymerizable group, an isocyanate group, an alkoxysilyl group, a silanol group, or the like (for example, epoxy-based resins, unsaturated polyester-based resins, urethane-based resins, silicone-based resins, and the like)), and photocurable (ionizing radiation-curable) compounds that are cured by ultraviolet light, electron beams, or the like (ultraviolet-curable compounds such as photocurable monomers and oligomers, and the like).

[0040] Examples of desirable curable resin precursors include photocurable compounds that cure in a short time when exposed to ultraviolet light, electron beams, or the like. Of these, ultraviolet curable compounds are particularly practical. In order to improve resistance, such as scratch resistance, it is desirable for the photocurable compound to have two or more (preferably 2 to 15, more preferably about 4 to 10) polymerizable unsaturated bonds in the molecule. Specifically, the photocurable compound is desirably an epoxy (meth)acrylate, a urethane (meth)acrylate, a polyester (meth)acrylate, a silicone (meth)acrylate, or a polyfunctional monomer having at least two polymerizable unsaturated bonds.

[0041] The curable resin precursor may contain a curing agent according to its type. For example, the thermosetting resin precursor may contain a curing agent such as an amine or a polycarboxylic acid, and the photocurable resin precursor may contain a photopolymerization initiator. Examples of the photopolymerization initiator include conventional components such as acetophenones or propiophenones, benzils, benzoins, benzophenones, thioxanthones, and acylphosphine oxides.

[0042] The curable resin precursor may also contain a curing accelerator, such as a tertiary amine (dialkylaminobenzoic acid ester, etc.) or a phosphine-based photopolymerization accelerator.

[0043] In the manufacturing process of the antiglare layer 4, at least two of the polymers and curable resin precursors contained in the solution that serves as the material for the antiglare layer 4 are used in a combination that causes phase separation from each other near the processing temperature. Examples of combinations that cause phase separation include (a) a combination in which multiple types of polymers are immiscible with each other and cause phase separation, (b) a combination in which a polymer and a curable resin precursor are immiscible with each other and cause phase separation, and (c) a combination in which multiple curable resin precursors are immiscible with each other and cause phase separation. Among these combinations, typical examples include (a) a combination of multiple types of polymers and (b) a combination of a polymer and a curable resin precursor. In particular, (a) a combination of multiple types of polymers is desirable.

[0044] Typically, the polymer and the cured resin or crosslinked resin produced by curing the curable resin precursor have different refractive indices. Also, typically, the refractive indices of the multiple types of polymers (first polymer and second polymer) are also different. The refractive index difference between the polymer and the cured resin or crosslinked resin, and the refractive index difference between the multiple types of polymers (first polymer and second polymer), are preferably, for example, values ​​in the range of 0 to 0.04, more preferably 0 to 0.02.

[0045] The antiglare layer 4 may contain a matrix resin having a phase-separated structure and a plurality of fine particles (fillers) dispersed in the matrix resin. The fine particles may be either organic fine particles or inorganic fine particles. The antiglare layer 4 may contain a plurality of types of fine particles that are different in material or average particle size.

[0046] Examples of organic particles include crosslinked acrylic particles and crosslinked styrene particles. Examples of inorganic particles include silica (SiO ２ ), zirconia (ZrO ２ ), titania (TiO ２ ), and other various metal oxide fine particles can be exemplified. Examples of metal oxides include indium tin oxide, tin oxide, indium oxide, germanium oxide, zinc oxide, and aluminum oxide. Examples of inorganic fine particles include metal fluoride particles, metal sulfide particles, metal nitride particles, and metal particles. It is desirable for the fine particles contained in the antiglare layer 4 to have good transparency. For example, when the fine particles contain silica, it is easier to improve the hardness of the antiglare film 2. For example, the refractive index difference between the fine particles contained in the antiglare layer 4 and the matrix resin can be set to a value in the range of 0 to 0.5. This refractive index difference is desirably, for example, a value in the range of 0 to 0.3, and more desirably, a value in the range of 0 to 0.2.

[0047] The average particle size of the fine particles is not particularly limited and can be set to a value in the range of 0.5 μm to 10 μm, for example. This average particle size is preferably a value in the range of 0.5 μm to 8.0 μm, and more preferably a value in the range of 1.0 μm to 6.0 μm.

[0048] The average particle size referred to in this specification is, for example, the volume average particle size (MV value) measured by a laser diffraction scattering method (the same applies to the average particle size mentioned below). The fine particles may be solid or hollow. For example, by setting the average particle size of the fine particles to a value that is not too small, anti-glare properties can be easily obtained. Furthermore, for example, by setting the average particle size of the fine particles to a value that is not too large, glare can be easily suppressed.

[0049] The thickness of the antiglare layer 4 can be set appropriately, for example, to a value in the range of 0.3 μm to 20 μm. The thickness is preferably, for example, in the range of 1 μm to 15 μm, and more preferably in the range of 1 μm to 10 μm. The thickness can usually be set to, for example, a value in the range of 2 μm to 10 μm (particularly, a value in the range of 3 μm to 7 μm).

[0050] The antiglare layer 4 may contain conventional additives, such as organic or inorganic particles, stabilizers (antioxidants, ultraviolet absorbers, etc.), surfactants, water-soluble polymers, fillers, crosslinking agents, coupling agents, colorants, flame retardants, lubricants, waxes, preservatives, viscosity modifiers, thickeners, leveling agents, and antifoaming agents, within limits that do not impair the optical properties.

[0051] [Example of Manufacturing Method of Antiglare Film] As an example, a manufacturing method of the antiglare film 2 includes a preparation step of preparing a solution (hereinafter also simply referred to as a solution) that will be the material of the antiglare layer 4, a formation step of applying the solution prepared in the preparation step to the surface of a predetermined support (substrate film 3 in this embodiment), evaporating the solvent in the solution, and forming a phase-separated structure by spinodal decomposition from the liquid phase, and a curing step of curing the curable resin precursor after the formation step.

[0052] In the preparation step, a solution containing a solvent and a resin composition for constituting the antiglare layer 4 is prepared. The solvent can be selected depending on the types and solubility of the polymers and curable resin precursors contained in the antiglare layer 4. Any solvent can be used as long as it can uniformly dissolve at least the solid components (multiple types of polymers and curable resin precursors, a reaction initiator, and other additives).

[0053] Examples of solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc. The solvent may also be a mixed solvent.

[0054] The resin composition is preferably a composition containing the thermoplastic resin, a photocurable compound, a photopolymerization initiator, the thermoplastic resin, and the photocurable compound, or a composition containing the multiple types of mutually incompatible polymers, a photocurable compound, and a photopolymerization initiator.

[0055] The concentration of the solutes (polymer and curable resin precursor, reaction initiator, and other additives) in the solution can be adjusted within a range in which phase separation of the multiple resin components occurs and within a range in which the flowability, coatability, etc. of the solution are not impaired.

[0056] The external haze value, internal haze value, antiglare properties, etc. of the antiglare layer 4 can vary depending on the combination and weight ratio of the resin compositions in the solution, or the application conditions of the preparation step, formation step, and curing step, etc. Therefore, an antiglare film 2 having the desired physical properties can be produced by forming an antiglare layer while changing each condition and measuring and understanding the physical properties of the obtained antiglare layer in advance.

[0057] In the forming step, the solution prepared in the preparation step is cast or applied onto the surface of a support (here, as an example, the base film 3). Examples of the method for casting or applying the solution include conventional methods, such as spraying, spinning, roll coating, air knife coating, blade coating, rod coating, reverse coating, bar coating, comma coating, dip coating, dip-squeeze coating, die coating, gravure coating, microgravure coating, and silk screen coating.

[0058] The solvent is evaporated and removed from the solution cast or coated on the surface of the support by drying. As the solution condenses during this evaporation process, phase separation occurs due to spinodal decomposition from the liquid phase of multiple resin components, forming a phase-separated structure. The uneven shape of the surface 4a due to the phase-separated structure can be formed by setting drying conditions and formulations that ensure a certain level of melt fluidity of the resin components after solvent evaporation.

[0059] For example, the evaporation of the solvent is desirably carried out by heat drying, since this facilitates the formation of convex portions on the surface 4a of the antiglare layer 4. By adjusting the drying temperature so that it is not too low and the drying time so that it is not too short, a sufficient amount of heat is imparted to the resin component, preventing a decrease in the melt fluidity of the resin component and facilitating the formation of convex portions.

[0060] On the other hand, if the drying temperature is too high or the drying time is too long, the convex portions that have been formed may flow and lose their height, but the structure of the convex portions is maintained. Therefore, the drying temperature and drying time can be used as a means for adjusting the antiglare properties and slip properties of the antiglare layer 4 by changing the height of the convex portions.

[0061] As phase separation from the liquid phase of multiple resin components by spinodal decomposition progresses, a co-continuous phase structure is formed and coarsens, and the continuous phase becomes discontinuous, forming a droplet phase structure (a sea-island structure of independent phases, such as spherical, true spherical, discoidal, or ellipsoidal). Depending on the degree of phase separation, an intermediate structure between the co-continuous phase structure and the droplet phase structure (a phase structure in the process of transitioning from the co-continuous phase to the droplet phase) can also be formed. After the solvent is removed, a layer with fine irregularities is formed on the surface.

[0062] In this way, by forming fine irregularities on the surface of the layer through phase separation, it is possible to adjust the external haze value of the antiglare layer 4, for example, without dispersing fine particles in the antiglare layer 4. Furthermore, by omitting the fine particles, it is possible to easily adjust the haze value of the antiglare layer 4 while suppressing the internal haze value relative to the external haze value. Note that by adding fine particles to the solution in the preparation step, an antiglare layer 4 containing fine particles can also be formed.

[0063] In the curing step, the phase separation structure formed in the forming step is fixed by curing the curable resin precursor in the solution, thereby forming the antiglare layer 4. The curable resin precursor is cured by heating, irradiating with active energy rays, or a combination of these methods, depending on the type of curable resin precursor. The type of active energy rays to be irradiated is selected depending on the type of photocurable component, etc.

[0064] The irradiation of the active energy rays may be carried out in an inert gas atmosphere. When the active energy rays are ultraviolet rays, a far ultraviolet lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp, a laser light source (a light source such as a helium-cadmium laser or an excimer laser), or the like can be used as the light source.

[0065] When forming the adhesive layer 5, a solution containing an adhesive component is prepared, and then the solution is applied to the other surface of the base film 3 by a conventional method, for example, the casting method or coating method described above in the formation step, followed by drying, thereby forming the adhesive layer 5. The antiglare film 2 is produced through the above-mentioned steps.

[0066] Here, for example, by not only reducing the unevenness of the surface 4a of the antiglare layer 4 but also increasing the slope of the unevenness to make the unevenness steeper and by increasing the number of unevennesses, it is possible to improve the antiglare properties of the antiglare film 2 as well as the glare suppression effect.

[0067] The basic method for forming the antiglare layer of the present disclosure is not particularly limited to the above-described method, and known methods can be used. Examples of known methods include the above-described formation method based on a phase-separated structure of multiple resin components, as well as a formation method based on a microparticle dispersion method in which the antiglare layer 104 is formed using a matrix resin 40 and multiple microparticles 41, as described in the second embodiment. Another example is a transfer formation method in which a previously prepared mold (master mold) is used to transfer the surface irregularities to form the antiglare layer. In this case, for example, a mold in which a metal film is formed by electrodeposition coating or the like on a previously manufactured antiglare film or the like can be used.

[0068] Another example of a basic method for forming an anti-glare layer is a method in which the surface of the anti-glare layer material is cut using a laser or the like to form an uneven shape on the surface of the anti-glare layer. Another example is a method in which the anti-glare layer material is polished using a shot blasting method using a projectile such as sand or beads to form an uneven shape on the surface of the anti-glare layer. Another example is a method in which the anti-glare layer material is etched to form an uneven shape on the surface of the anti-glare layer. Hereinafter, other embodiments will be described, focusing on the differences from the first embodiment.

[0069] Second Embodiment [Anti-glare Film] Fig. 3 is an enlarged cross-sectional view of a surface 104a of an anti-glare layer 104 of an anti-glare film 102 according to a second embodiment. As shown in Fig. 3, the anti-glare film 102 according to the second embodiment includes an anti-glare layer 104. The anti-glare film 102 includes a substrate film 3, similar to the anti-glare film 2. The surface 104a of the anti-glare layer 104 opposite to the substrate film 3 side has an uneven shape similar to the surface 4a of the anti-glare layer 4.

[0070] The antiglare layer 104 includes a matrix resin 40 and a plurality of microparticles 41 dispersed in the matrix resin 40. This gives the antiglare layer 104 a microparticle dispersion structure. Some of the microparticles 41 dispersed in the matrix resin 40 in the antiglare layer 104 are arranged so as to protrude outward from the surface of the matrix resin 40, thereby forming an uneven shape on the surface 104 a of the antiglare layer 104.

[0071] Even when multiple microparticles 41 are used to form an uneven shape on the surface 104a of the anti-glare layer 104, as in this embodiment, by selecting materials that will strengthen the repulsive interaction between the microparticles 41 and other resins and solvents when forming the anti-glare layer 104, it is possible to cause moderate aggregation of the microparticles 41 and form a steep, high-number-density uneven distribution structure on the surface 104a of the anti-glare layer 104.

[0072] The shape of the fine particles 41 is not limited, and may be spherical or ellipsoidal. The fine particles 41 are formed to be solid, but may also be formed to be hollow. When the fine particles 41 are formed to be hollow, the hollow portions of the fine particles 41 may be filled with air or other gases. In the antiglare layer 104, each fine particle 41 may be dispersed as a primary particle, or multiple secondary particles formed by aggregation of multiple fine particles 41 may be dispersed.

[0073] The refractive index difference between the matrix resin 40 and the fine particles 41 is set to a value in the range of 0 to 0.5, for example. This refractive index difference is preferably a value in the range of 0 to 0.3, and more preferably a value in the range of 0 to 0.2.

[0074] The average particle diameter of the fine particles 41 is set to, for example, a value in the range of 0.5 μm to 10 μm, and is preferably, for example, a value in the range of 0.5 μm to 8.0 μm, and more preferably, a value in the range of 1.0 μm to 6.0 μm.

[0075] Furthermore, for example, it is desirable that there is small variation in the particle size of the fine particles 41. In this case, for example, in the particle size distribution of the fine particles 41 contained in the antiglare layer 104, it is desirable that the average particle size of 50% by weight or more of the fine particles 41 contained in the antiglare layer 104 has a variation of 1.0 μm or less.

[0076] In this way, the microparticles 41, whose particle diameters are relatively uniform and whose average particle diameter is set within the above range, form uniform and appropriate unevenness on the surface of the antiglare layer 104. The ratio of the weight of the matrix resin 40 in the antiglare layer 104 to the total weight of the plurality of microparticles 41 can be set as appropriate. In this embodiment, the ratio G2 / G1 of the weight G1 of the matrix resin 40 in the antiglare layer 104 to the total weight G2 of the plurality of microparticles 41 is set to a value in the range of 0.01 to 2.0, for example. The ratio G2 / G1 is preferably, for example, a value in the range of 0.02 to 1.5, and more preferably a value in the range of 0.03 to 1.0.

[0077] The fine particles 41 dispersed in the matrix resin 40 may be either inorganic or organic. For example, it is desirable that the fine particles 41 have good transparency. An example of organic fine particles is plastic beads. Examples of plastic beads include styrene beads (refractive index 1.59), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), acrylic-styrene beads (refractive index 1.54), polycarbonate beads, and polyethylene beads. The styrene beads may be cross-linked styrene beads, and the acrylic beads may be cross-linked acrylic beads. It is desirable that the plastic beads have hydrophobic groups on the surface. An example of such plastic beads is styrene beads.

[0078] Examples of the matrix resin 40 include at least one of a photocurable resin that is cured by active energy rays, a solvent-drying resin that is cured by drying a solvent added during coating, and a thermosetting resin.

[0079] Examples of photocurable resins include those having an acrylate functional group, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiolpolyene resins, and oligomers, prepolymers, and reactive diluents such as (meth)acrylates of polyfunctional compounds such as polyhydric alcohols.

[0080] Specific examples of these include monofunctional monomers such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene, and N-vinylpyrrolidone, as well as polyfunctional monomers such as polymethylolpropane tri(meth)acrylate, hexanediol (meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate.

[0081] When the photocurable resin is an ultraviolet-curable resin, it is desirable to use a photopolymerization initiator. Examples of photopolymerization initiators include acetophenones, benzophenones, Michler's benzoyl benzoate, α-amyloxime ester, tetramethylthiuram monosulfide, and thioxanthones. It is also desirable to mix a photosensitizer with the photocurable resin. Examples of photosensitizers include n-butylamine, triethylamine, and poly-n-butylphosphine.

[0082] Examples of solvent-drying resins include known thermoplastic resins. Examples of such thermoplastic resins include styrene-based resins such as polystyrene resins, acrylic resins, (meth)acrylic resins, vinyl-based resins such as vinyl acetate resins, vinyl ether-based resins, acetal resins, halogen-containing resins, alicyclic olefin-based resins, polycarbonate-based resins, polyester-based resins, polyamide-based resins, cellulose-based resins, cellulose derivatives, silicone-based resins, and rubber or elastomers. Desirable solvent-drying resins are those that are soluble in organic solvents and have excellent moldability, film-forming properties, transparency, and weather resistance. Examples of such solvent-drying resins include styrene-based resins, (meth)acrylic resins, alicyclic olefin-based resins, polyester-based resins, and cellulose derivatives (cellulose esters, etc.).

[0083] Examples of thermosetting resins include phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, unsaturated polyester resins, polyurethane resins, epoxy resins, aminoalkyd resins, melamine-urea co-condensation resins, silicon resins, polysiloxane resins, etc. When a thermosetting resin is used as the matrix resin 40, at least one of a crosslinking agent, a curing agent such as a polymerization initiator, a polymerization accelerator, a solvent, and a viscosity modifier may be used in combination.

[0084] [Example of a method for manufacturing an antiglare film] As an example, a method for manufacturing the antiglare film 102 includes a preparation step of preparing a solution that will be the material for the antiglare layer 104, a coating step of coating the solution prepared in the preparation step onto the surface of a predetermined support (in this embodiment, the base film 3), and a curing step of curing the resin in the coated solution.

[0085] In the preparation step, a solution containing a solvent, a resin composition for constituting the antiglare layer 104, and fine particles 41 is prepared. Examples of the solvent include at least one of alcohols (isopropyl alcohol, methanol, ethanol, etc.), ketones (methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), halogenated hydrocarbons, and aromatic hydrocarbons (toluene, xylene, etc.). A known leveling agent may also be added to the solution. For example, the use of a fluorine-based or silicone-based leveling agent can impart good scratch resistance to the antiglare layer 104.

[0086] In the coating step, the solution prepared in the preparation step is cast or coated on the surface of a support (here, as an example, the base film 3) by the same method as in Embodiment 1. The solvent is removed from the solution cast or coated on the surface of the support by evaporation through drying.

[0087] When the matrix resin 40 is a photocurable resin, a curing step using, for example, ultraviolet light or electron beams is performed after the coating step. Examples of ultraviolet light sources include various mercury lamps, ultraviolet carbon arc lamps, black lights, and metal halide lamps. Examples of the wavelength range of the ultraviolet light include a wavelength range of 190 nm to 380 nm.

[0088] Examples of electron beam sources include known electron beam accelerators, such as Van de Graaff type, Cockcroft-Walton type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type.

[0089] The matrix resin 40 contained in the solution is cured, thereby fixing the positions of the microparticles 41 in the matrix resin 40. As a result, a plurality of microparticles 41 are dispersed in the matrix resin 40, and an antiglare layer 104 having a structure in which the microparticles 41 form an uneven shape on the surface 104a.

[0090] (Third embodiment) Fig. 4 is a partial cross-sectional view of an antiglare film 202 having an antireflection layer 9 of a first structure according to a third embodiment. Fig. 5 is a partial cross-sectional view of an antiglare film 302 having an antireflection layer 9 of a second structure according to a third embodiment. Fig. 6 is a partial cross-sectional view of an antiglare film 402 having an antireflection layer 9 of a third structure according to a third embodiment. Fig. 6 shows an antireflection layer 9 of a four-layer structure as an example.

[0091] As shown in FIGS. 4 to 6 , the antiglare films 202, 302, and 402 of the present embodiment include an antireflection layer 9 disposed on the surface 4a of the antiglare layer 4 opposite the substrate film 3. The antireflection layer 9 prevents reflection of external light. As shown in FIG. 4 , the antireflection layer 9 has, for example, a first structure including only a single low-refractive index layer 90. Alternatively, as shown in FIG. 5 , the antireflection layer 9 has a second structure including a laminate structure of a single low-refractive index layer 90 and a single high-refractive index layer 91 having a higher refractive index than the low-refractive index layer 90. Alternatively, as shown in FIG. 6 , the antireflection layer 9 has a third structure, which is a laminate structure of three or more layers including low-refractive index layers 90 and high-refractive index layers 91 arranged alternately. The low-refractive index layer 90 has, for example, a refractive index lower than that of the antiglare layer 4. The low-refractive index layer 90 may have antifouling properties. In this case, the low-refractive index layer 90 may contain an antifouling agent such as a silicone-based compound or a fluorine-based compound.

[0092] The method for forming the low refractive index layer 90 and the high refractive index layer 91 is not particularly limited, and examples thereof include a known wet method or dry method. When the antireflection layer 9 has the first structure or the second structure, for example, a wet method is desirable. When the antireflection layer 9 has the third structure, for example, a dry method is desirable.

[0093] There is no particular limitation on the refractive index of the antireflection layer 9. The thickness of the antireflection layer 9 can be set within a range that ensures the antiglare properties of the antiglare film 202. For example, the thickness of the antireflection layer 9 can be set so that the spectral reflectance in the vicinity of 550 nm is lowest when the spectral reflectance spectrum of the antiglare film 202 is measured.

[0094] When the antireflection layer 9 has the first structure or the second structure, the refractive index of the low-refractive-index layer 90 is, for example, a value in the range of 1.34 or more. In this case, the refractive index of the low-refractive-index layer 90 is preferably, for example, a value in the range of 1.34 to 1.45, more preferably a value in the range of 1.34 to 1.4, even more preferably a value in the range of 1.34 to 1.39, and even more preferably a value in the range of 1.34 to 1.38. For example, by setting the refractive index of the low-refractive-index layer 90 so that it is not too high, it is possible to suppress a decrease in the antireflection properties of the antireflection layer 9.

[0095] When the antireflection layer 9 has the first structure or the second structure, the thickness of the low refractive index layer 90 is preferably, for example, in the range of 50 nm to 300 nm, more preferably in the range of 60 nm to 150 nm, even more preferably in the range of 80 nm to 120 nm, and still more preferably in the range of 90 nm to 110 nm.

[0096] The configuration of the low refractive index layer 90 can be found, for example, in JP 2001-100006 A, JP 2008-58723 A, and WO 2016 / 039125. The low refractive index layer 90 is made of, for example, a composition containing a low refractive index resin. The low refractive index layer 90 may also be made of, for example, a cured product of a composition containing a curable resin and a fluorine-containing compound or a low refractive index inorganic filler.

[0097] Examples of low refractive index resins include fluororesins such as methylpentene resin, diethylene glycol bis(allyl carbonate) resin, polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF). Examples of curable resins include fluorine-free photocurable resins used as materials for the antiglare layer 4. Examples of fluorine-containing compounds include fluorine-containing photocurable resins used as materials for the antiglare layer 4.

[0098] The proportion of the fluorine-containing compound in the composition constituting the low refractive index layer 90 is, for example, a value in the range of 1% by mass or more relative to the entire composition. This proportion may be, for example, a value in the range of 5% by mass or more and 90% by mass or less. Examples of low refractive index inorganic fillers include fillers described in JP 2001-100006 A. Examples of such inorganic fillers include low refractive index fillers such as silica and magnesium fluoride, and silica is particularly desirable. Examples of silica include hollow silica described in JP 2001-233611 A or JP 2003-192994 A. Among these, hollow silica is desirable, for example, from the viewpoint of being able to suppress an increase in haze and improve transparency.

[0099] The number average particle size (number average primary particle size) of the inorganic filler (particularly hollow silica) measured by electron microscopy is, for example, a value in the range of 100 nm or less. For example, this number average particle size is preferably a value in the range of 80 nm or less. For example, this number average particle size is preferably a value in the range of 10 nm to 80 nm, and more preferably a value in the range of 20 nm to 70 nm.

[0100] The proportion of the low-refractive-index inorganic filler (particularly hollow silica) in the composition constituting the low-refractive-index layer 90 is, for example, 1% by mass or more relative to the total composition. This proportion may be, for example, 5% by mass or more and 90% by mass or less. The low-refractive-index inorganic filler may be surface-modified with a coupling agent (titanium coupling agent, silane coupling agent). Furthermore, the composition containing the low-refractive-index inorganic filler may contain other inorganic fillers to improve coating strength.

[0101] The composition of the low refractive index layer 90 may contain a curing agent or known additives that are used as materials for the antiglare layer 4. The antiglare layer of this embodiment may be formed by any of the formation methods described in the first and second embodiments.

[0102] As shown in FIG. 5 , when the anti-reflection layer 9 has the second structure, the high-refractive index layer 91 is preferably disposed, for example, closer to the anti-glare layer 4 than the low-refractive index layer 90. The refractive index of the high-refractive index layer 91 can be appropriately set within a range higher than the refractive index of the low-refractive index layer 90. In this case, the refractive index of the high-refractive index layer 91 is, for example, a value in the range of 1.53 or higher. In this case, the refractive index of the high-refractive index layer 91 is preferably, for example, a value in the range of 1.54 or higher, more preferably a value in the range of 1.55 or higher, and even more preferably a value in the range of 1.56 or higher. In this case, the refractive index of the high-refractive index layer 91 is preferably, for example, a value in the range of 1.85 or lower, more preferably a value in the range of 1.80 or lower, and even more preferably a value in the range of 1.75 or lower.

[0103] When the antireflection layer 9 has the second structure, the thickness of the high-refractive index layer 91 is, for example, a value in the range of 200 nm or less. In this case, the thickness of the high-refractive index layer 91 is preferably, for example, a value in the range of 180 nm or less, and more preferably a value in the range of 150 nm or less. In this case, the thickness of the high-refractive index layer 91 is also preferably, for example, a value in the range of 50 nm or more, and more preferably a value in the range of 70 nm or more.

[0104] The configuration of the high-refractive index layer 91 can be seen, for example, in the configuration of the high-refractive index layer described in JP 2016-097529 A. The high-refractive index layer 91 is composed of, for example, a composition containing a high-refractive index resin. The high-refractive index layer 91 may also be composed of, for example, a cured product of a composition containing inorganic fine particles. Examples of the particle size of the inorganic fine particles include nanometer-sized particles. The number-average particle size (number-average primary particle size) of the inorganic fine particles is, for example, a value in the range of 1 nm to 100 nm. The number-average particle size of the inorganic fine particles is, for example, preferably, a value in the range of 2 nm to 50 nm, more preferably, a value in the range of 3 nm to 40 nm, and even more preferably, a value in the range of 5 nm to 30 nm. The number-average particle size of the inorganic fine particles can be measured by a conventional method using a particle size distribution analyzer. The number-average particle size of the inorganic fine particles can be measured, for example, using a particle size analyzer (laser particle size analyzer "PAR-III" manufactured by Otsuka Electronics Co., Ltd.) based on dynamic light scattering.

[0105] The shape of the inorganic fine particles is not particularly limited. Examples of the shape of the inorganic fine particles include spherical, ellipsoidal, polygonal (polygonal pyramidal, cuboidal, rectangular parallelepiped, etc.), plate-like, rod-like, and amorphous. The shape of the inorganic fine particles is preferably an isotropic shape such as a substantially spherical shape, since it can isotropically scatter light and improve visibility.

[0106] Examples of inorganic compounds constituting the inorganic fine particles include simple metals and metal oxides. For example, metal oxides are desirable because they can increase the refractive index of the high-refractive-index layer 91. Examples of metal oxides include Group 4A metal oxides (e.g., titanium oxide, zirconium oxide, etc.), Group 5A metal oxides (e.g., vanadium oxide, etc.), Group 6A metal oxides (e.g., molybdenum oxide, tungsten oxide, etc.), Group 7A metal oxides (e.g., manganese oxide, etc.), Group 8 metal oxides (e.g., nickel oxide, iron oxide, etc.), Group 1B metal oxides (e.g., copper oxide, etc.), Group 2B metal oxides (e.g., zinc oxide, etc.), Group 3B metal oxides (e.g., aluminum oxide, indium oxide, etc.), Group 4B metal oxides (e.g., silicon oxide, tin oxide, etc.), and Group 5B metal oxides (e.g., antimony oxide, etc.). These metal oxides can be used alone or in combination. Among these metal oxides, for example, the metal oxides of Group 4A of the periodic table, such as titanium oxide and zirconium oxide, are desirable, and zirconium oxide is particularly desirable, because they can increase the refractive index of the high refractive index layer 91 with a small proportion and can suppress an increase in haze even if the amount added is increased.

[0107] The high refractive index resin includes, for example, a curable resin. An example of the curable resin is an ultraviolet curable resin. Desirable examples of the ultraviolet curable resin include polyfunctional (meth)acrylates such as pentaerythritol tri(meth)acrylate and dipentaerythritol hexa(meth)acrylate.

[0108] 6 , when the antireflection layer 9 has the third structure, the third structure preferably includes, for example, a low refractive index layer 90 disposed on the outermost surface of the antiglare film 202. When the antireflection layer 9 has the third structure, the thickness of each high refractive index layer 91 preferably ranges from 10 nm to 200 nm, and more preferably ranges from 20 nm to 70 nm. In this case, the refractive index of each high refractive index layer 91 preferably ranges from 2.00 to 2.60, for example.

[0109] When the antireflection layer 9 has the third structure, the thickness of each low-refractive-index layer 90 is preferably, for example, 5 nm to 200 nm, more preferably 20 nm to 120 nm, and in this case, the refractive index of each low-refractive-index layer 90 is preferably, for example, 1.20 to 1.60.

[0110] The antireflection layer 9 is not limited to having any of the first to third structures. The antireflection layer 9 may have a structure including another layer, such as at least one medium-refractive index layer having a refractive index higher than that of the low-refractive index layer 90 and lower than that of the high-refractive index layer 91. In this case, the medium-refractive index layer may be combined with at least one of the low-refractive index layer 90 and the high-refractive index layer 91, for example.

[0111] Fourth Embodiment FIG. 7 is a schematic cross-sectional view of an optical member 10 according to a fourth embodiment. As shown in FIG. 7, the optical member 10 is an application example of an antiglare film 2. The optical member 10 includes an antiglare film 2 and a polarizing plate 6 disposed over the antiglare film 2. The polarizing plate 6 polarizes incident light from outside. The polarizing plate 6 of this embodiment includes a retardation film 8 and a plate-shaped polarizing element 7 disposed over the retardation film 8. Examples of materials for the polarizing element 7 include polyvinyl alcohol (PVA), polyvinyl formal, polyvinyl acetal, and saponified ethylene-vinyl acetate copolymers dyed with iodine or the like and stretched. Examples of materials for the retardation film 8 include triacetyl cellulose and cycloolefin polymer. According to this embodiment, light incident on the retardation film 8 is incident on the polarizing element 7, polarized, and then passes through the antiglare film 2 in a direction from the substrate film 3 to the antiglare layer 4.

[0112] The optical member 10 may include, for example, any of the antiglare films 102, 202, 302, and 402 of the other embodiments instead of the antiglare film 2 of the first embodiment. The configuration of the polarizing plate 6 is not limited, and any known configuration can be used. For example, the polarizing plate 6 may include a protective film containing polyethylene terephthalate (PET) or the like.

[0113] Fifth Embodiment FIG. 8 is a schematic cross-sectional view of a display device 20 according to a fifth embodiment. As shown in FIG. 8, the display device 20 is an application example of the optical member 10. The display device 20 includes a light source 17, a polarizing plate 18 arranged on the optical path of the light source 17, a panel-shaped display element 15 arranged on top of the polarizing plate 18 with its surface opposite to the image display side facing the polarizing plate 18, and an optical member 10 arranged on the image display side of the display element 15. As an example, the display element 15 includes an LCD. The light source 17 is a backlight. The surface 4a of the antiglare layer 4 in the optical member 10 is located at the top in the thickness direction of the display device 20. The polarizing plate 18 is a polarizing plate separate from the polarizing plate 6 included in the optical member 10.

[0114] When the display device 20 is driven, the light emitted from the light source 17 is polarized by the polarizing plate 18 and then sequentially enters the display element 15 and the optical member 10. Accordingly, the image on the display element 16 is visible due to the light emitted to the outside from the surface 4 a of the antiglare layer 4 of the optical member 10.

[0115] (Confirmation Test) Next, performance confirmation tests of the present disclosure will be described, but the present disclosure is not limited to the examples shown below. Antiglare films of Examples 1 to 13 and Comparative Examples 1 to 7 were manufactured based on the procedures shown below. Examples 1, 3, 5, and 7 to 13 have an antiglare layer 4 having a phase-separated structure and correspond to antiglare film 2. Examples 2 and 4 have an antiglare layer 104 having a fine particle dispersion structure and correspond to antiglare film 102. Example 6 has an antiglare layer 4 and an antireflection layer 9 and corresponds to antiglare film 202. The antiglare layer 4 of Example 6 also has a phase-separated structure. Comparative Examples 1, 3 to 6 have an antiglare layer having a fine particle dispersion structure. Comparative Examples 2 and 7 have an antiglare layer having a phase-separated structure. Examples 7 to 13 and Comparative Example 7 have the same antiglare layer 4 as Example 1, but differ from Example 1 in the thickness D of the substrate film 3, the retardation Re, and the integrated value (D×Re). As materials for the antiglare films according to Examples 1 to 13 and Comparative Examples 1 to 7, the following materials (M1) to (M29) were used.

[0116] [Materials] (M1) Acrylic polymer having a polymerizable group: "ACA Z322M" manufactured by Daicel Corporation, solid content 40% by weight, solvent: 1-methoxy-2-propanol (MMPG) (boiling point 119°C) (M2) Cellulose acetate propionate: "CAP-482-20" manufactured by Eastman Chemical Company, acetylation degree = 2.5%, propionylation degree = 46%, polystyrene equivalent number average molecular weight 75,000 (M3) Silicone acrylate: "EB1360" manufactured by Daicel Allnex Corporation (M4) Silicone hard coating material: "AS-201S" manufactured by Tokushiki Corporation (M5) Urethane acrylate: "DCL-002" manufactured by Negami Chemical Industries, Ltd. (M6) Dipentaerythritol hexaacrylate: "DPHA" manufactured by Daicel Allnex Corporation (M7) Pentaerythritol tetraacrylate: "PETRA" manufactured by Daicel Allnex Co., Ltd. (M8) PMMA (polymethyl methacrylate) beads A: "SSX-105" manufactured by Sekisui Plastics Co., Ltd., average particle size 5 μm, refractive index 1.49 (M9) PMMA beads B: "SSX-103" manufactured by Sekisui Plastics Co., Ltd., average particle size 3 μm, refractive index 1.49 (M10) PMMA beads C: "SSX-115HXE" manufactured by Sekisui Plastics Co., Ltd., average particle size 3 μm, refractive index 1.49 (M11) Silica fine particles A: "KE-P250" manufactured by Nippon Shokubai Co., Ltd., average particle size 2.5 μm, refractive index 1.43 (M12) Silica fine particles B: "Sylysia 310P" manufactured by Fuji Silysia Chemical Co., Ltd., average particle size 2.7 μm (M13) Silica fine particles C: "Silohorbic 100" manufactured by Fuji Silysia Chemical Ltd., average particle size 2.7 μm

[0117] (M14) Hollow silica-dispersed acrylic hard coating liquid: "P-5063" manufactured by JGC Catalysts and Chemicals Co., Ltd., solid content 3% by weight (M15) Acrylic hard coating agent: "HX-MR4" manufactured by Kyoeisha Chemical Co., Ltd. (M16) Styrene beads: "SX-350H" manufactured by Soken Chemical & Engineering Co., Ltd. (M17) Fluorine-based compound A having a polymerizable group: "Ftergent 602A" manufactured by Neos Co., Ltd., solvent: ethyl acetate, solid content concentration: 50% by weight (M18) Fluorine-based compound B having a polymerizable group: "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd., solid content concentration 20% by weight (M19) Photoinitiator A: "Omnirad 184" manufactured by IGM Resin B.V. (M20) Photoinitiator B: IGM Resin B.V. (M21) Polyethylene terephthalate (PET) film A: Mitsubishi Plastics, Inc. "Diafoil O321", film thickness 50 μm (M22) Polyethylene terephthalate (PET) film B: Mitsubishi Plastics, Inc. "Diafoil O321", film thickness 75 μm (M23) Polyethylene terephthalate (PET) film C: Mitsubishi Plastics, Inc. "Diafoil O321", film thickness 100 μm (M24) Polyethylene terephthalate (PET) film D: Mitsubishi Plastics, Inc. "Diafoil O321", film thickness 125 μm (M25) Polyethylene terephthalate (PET) film E: Toyobo Co., Ltd. "Cosmoshine A4360", film thickness 50 μm (M26) Polyethylene terephthalate (PET) film F: "Cosmoshine A4360" manufactured by Toyobo Co., Ltd., film thickness 75 μm (M27) Polyethylene terephthalate (PET) film G: "Lumirror U-403" manufactured by Toray Industries, Inc., film thickness 23 μm (M28) Polyethylene terephthalate (PET) film H: "Lumirror U-403" manufactured by Toray Industries, Inc., film thickness 50 μm (M29) Polyethylene terephthalate (PET) film I: "Lumirror U-403" manufactured by Toray Industries, Inc., film thickness 100 μm

[0118] Example 1 A solution was prepared by dissolving 46 parts by weight of (M1) an acrylic polymer having a polymerizable group, 5 parts by weight of (M2) cellulose acetate propionate, 77 parts by weight of (M5) urethane acrylate, 1.5 parts by weight of (M19) photoinitiator A, 1.5 parts by weight of (M20) photoinitiator B, and 0.5 parts by weight of (M17) a fluorine-based compound A having a polymerizable group in a mixed solvent of 62 parts by weight of methyl ethyl ketone, 12 parts by weight of 1-butanol, 13 parts by weight of 1-methoxy-2-propanol, and 13 parts by weight of cyclohexanone.

[0119] This solution was cast onto a substrate film (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of approximately 8 µm. Then, a high-pressure mercury lamp was used to irradiate the coating with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer 4. In this way, an antiglare film 2 of Example 1 was produced.

[0120] Example 2 A solution was prepared by dissolving 50 parts by weight of (M6) dipentaerythritol hexaacrylate, 50 parts by weight of (M7) pentaerythritol tetraacrylate, 6.0 parts by weight of (M8) PMMA beads A, 2.0 parts by weight of (M19) photoinitiator A, 2.0 parts by weight of (M20) photoinitiator B, and 1.0 part by weight of (M17) fluorine-based compound A having a polymerizable group in a mixed solvent of 146 parts by weight of methyl ethyl ketone and 59 parts by weight of 1-methoxy-2-propanol.

[0121] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of about 5 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer 104. In this way, an antiglare film 102 of Example 2 was produced.

[0122] Example 3 A solution was prepared by dissolving 46 parts by weight of (M1) an acrylic polymer having a polymerizable group, 5 parts by weight of (M2) cellulose acetate propionate, 62 parts by weight of (M5) urethane acrylate, 15 parts by weight of (M6) dipentaerythritol hexaacrylate, 1.5 parts by weight of (M19) photoinitiator A, 1.5 parts by weight of (M20) photoinitiator B, and 0.5 parts by weight of (M17) a fluorine-based compound A having a polymerizable group in a mixed solvent of 62 parts by weight of methyl ethyl ketone, 12 parts by weight of 1-butanol, 13 parts by weight of 1-methoxy-2-propanol, and 13 parts by weight of cyclohexanone.

[0123] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of approximately 8 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer 4. In this way, an antiglare film 2 of Example 3 was produced.

[0124] Example 4 A solution was prepared by mixing 100 parts by weight of (M15) acrylic hard coating agent A and 10 parts by weight of (M16) styrene beads A and dissolving the mixture in 30 parts by weight of methyl ethyl ketone.

[0125] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of about 3 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film, with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer 104. In this way, an antiglare film 102 of Example 4 was produced.

[0126] Example 5 A solution was prepared by dissolving 50 parts by weight of (M1) an acrylic polymer having a polymerizable group, 4 parts by weight of (M2) cellulose acetate propionate, 76 parts by weight of (M5) urethane acrylate, 1 part by weight of (M3) silicone acrylate, 1.5 parts by weight of (M19) photoinitiator A, and 1.5 parts by weight of (M20) photoinitiator B in a mixed solvent of 176 parts by weight of methyl ethyl ketone and 28 parts by weight of 1-butanol.

[0127] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of approximately 7 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer 4. In this way, an antiglare film 2 of Example 5 was produced.

[0128] Example 6 A solution was prepared by dissolving 46 parts by weight of (M1) an acrylic polymer having a polymerizable group, 5 parts by weight of (M2) cellulose acetate propionate, 77 parts by weight of (M5) urethane acrylate, 1.5 parts by weight of (M19) photoinitiator A, 1.5 parts by weight of (M20) photoinitiator B, and 0.5 parts by weight of (M17) a fluorine-based compound A having a polymerizable group in a mixed solvent of 62 parts by weight of methyl ethyl ketone, 12 parts by weight of 1-butanol, 13 parts by weight of 1-methoxy-2-propanol, and 13 parts by weight of cyclohexanone.

[0129] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of approximately 8 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer 4. In this way, an intermediate film was obtained.

[0130] The hollow silica-dispersed acrylic hard coat solution (M14) was cast onto the surface of the intermediate film on which the antiglare layer 4 was formed using a wire bar, and the film was left in an oven at 70°C for 30 seconds to evaporate the solvent. Then, a high-pressure mercury lamp was used to cast the film onto the surface of the intermediate film on which the antiglare layer 4 was formed, and the film was left in an oven at 70°C for 30 seconds to evaporate the solvent. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to obtain a film in which a single-layer low refractive index layer 90 was formed on the surface of the antiglare layer 4 as the antireflection layer 9 having the first structure. The type of wire bar was selected to set the thickness of the antireflection layer 9 so that the spectral reflectance in the vicinity of 550 nm would be the lowest when the spectral reflectance spectrum of the film was measured. In this way, the antiglare film 202 of Example 6 was produced.

[0131] [Example 7] Antiglare film 2 of Example 7 was produced in the same manner as Example 1, except that (M21) PET film A was changed to (M22) PET film B. [Example 8] Antiglare film 2 of Example 8 was produced in the same manner as Example 1, except that (M21) PET film A was changed to (M23) PET film C. [Example 9] Antiglare film 2 of Example 9 was produced in the same manner as Example 1, except that (M21) PET film A was changed to (M24) PET film D. [Example 10] Antiglare film 2 of Example 10 was produced in the same manner as Example 1, except that (M21) PET film A was changed to (M25) PET film E.

[0132] [Example 11] An antiglare film 2 of Example 11 was produced in the same manner as Example 1, except that (M21) PET film A was changed to (M26) PET film F. [Example 12] An antiglare film 2 of Example 12 was produced in the same manner as Example 1, except that (M21) PET film A was changed to (M27) PET film G. [Example 13] An antiglare film of Example 13 was produced in the same manner as Example 1, except that (M21) PET film A was changed to (M29) PET film I.

[0133] Comparative Example 1 A solution was prepared by dissolving 50 parts by weight of (M6) dipentaerythritol hexaacrylate, 50 parts by weight of (M7) pentaerythritol tetraacrylate, 6.0 parts by weight of (M9) PMMA beads B, 2.0 parts by weight of (M19) photoinitiator A, 2.0 parts by weight of (M20) photoinitiator B, and 1.0 part by weight of (M17) fluorine-based compound A having a polymerizable group in a mixed solvent of 146 parts by weight of methyl ethyl ketone and 59 parts by weight of 1-methoxy-2-propanol.

[0134] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of about 5 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer. Thus, an antiglare film of Comparative Example 1 was produced.

[0135] Comparative Example 2 A solution was prepared by dissolving 50 parts by weight of (M1) an acrylic polymer having a polymerizable group, 7 parts by weight of (M2) cellulose acetate propionate, 76 parts by weight of (M5) urethane acrylate, 1 part by weight of (M3) silicone acrylate, 1.5 parts by weight of (M19) photoinitiator A, and 1.5 parts by weight of (M20) photoinitiator B in a mixed solvent of 176 parts by weight of methyl ethyl ketone and 28 parts by weight of 1-butanol.

[0136] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of approximately 7 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer. Thus, an antiglare film of Comparative Example 2 was produced.

[0137] Comparative Example 3 A solution was prepared by dissolving 100 parts by weight of (M7) pentaerythritol tetraacrylate, 14.0 parts by weight of (M11) silica fine particles, 2.0 parts by weight of (M19) photoinitiator A, 2.0 parts by weight of (M20) photoinitiator B, and 1.0 part by weight of (M18) fluorine-based compound B having a polymerizable group in a mixed solvent of 146 parts by weight of methyl ethyl ketone and 59 parts by weight of 1-methoxy-2-propanol.

[0138] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of about 5 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer. Thus, an antiglare film of Comparative Example 3 was produced.

[0139] Comparative Example 4 A solution was prepared by dissolving a mixture of 100 parts by weight of (M15) acrylic hard coating agent A and 10 parts by weight of (M12) silica fine particles B in 30 parts by weight of methyl ethyl ketone.

[0140] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of about 4 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film, with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer. Thus, an antiglare film of Comparative Example 4 was produced.

[0141] Comparative Example 5 A solution was prepared by dissolving a mixture of 100 parts by weight of (M15) acrylic hard coating agent A and 10 parts by weight of (M13) silica fine particles C in 30 parts by weight of methyl ethyl ketone.

[0142] This solution was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of about 3 µm. Then, a high-pressure mercury lamp was used to apply the coating to the film, with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer. Thus, an antiglare film of Comparative Example 5 was produced.

[0143] [Comparative Example 6] A liquid was prepared by mixing 260 parts by weight of (M4) silicone-based hard coating material and 1.5 parts by weight of (M10) PMMA beads C. This liquid was cast onto (M21) PET film A using a wire bar, and then left in an oven at 80°C for 1 minute to evaporate the solvent, forming a coating layer with a thickness of approximately 8 μm. Then, a high-pressure mercury lamp was used to irradiate the liquid with an integrated light intensity of 200 mJ / cm. ２ , peak irradiance 400 mW / cm ２ The coating layer was irradiated with ultraviolet light of wavelength 365 nm (measured value of 365 nm line) to cure the coating layer, thereby forming an antiglare layer. Thus, an antiglare film of Comparative Example 6 was produced.

[0144] Next, Safc and Smr1 were measured under the following conditions to evaluate the state of rainbow unevenness for each of the antiglare films of Examples 1 to 5 and Comparative Examples 1 to 6. Furthermore, retardation Re was measured for Examples 1, 7 to 13, and Comparative Example 7, and the integrated value (D×Re) was calculated to evaluate the state of rainbow unevenness.

[0145] Using an optical surface roughness meter "Vertscan R5500G" manufactured by Hitachi High-Tech Science Corporation, the fractal parameter Safc of the surface of the antiglare layer of each antiglare film opposite to the substrate film side and the area load ratio Smr1 separating the core portion from the protruding peak portion were measured in the following manner based on a method in accordance with ISO 25178.

[0146] [Setting conditions for optical surface roughness meter] Vibration isolation table: ON Objective lens: Nikon Corporation "5x / 0.13 OFN25 WD 9.3" Light source: Nikon Corporation "MODEL TE2-PS100W" Camera: Sony Corporation full pixel readout monochrome camera module "XC-HR-57" 1 / 2" CCD Upright microscope: Nikon Corporation "ECLIPSE LV150" Fiber optic light source: Nikon Corporation "LV-UEPI2"

[0147] [Setting conditions on the measurement screen] Camera: Sony Corporation full pixel readout monochrome camera module "XC-HR-57" 1 / 2" CCD Objective lens: 5X Lens barrel: 0.5X Body Zoom lens: No Relay Wavelength filter: 530 white

[0148] [Measurement conditions] Measurement mode: Wave Field of view size: 640 x 480 Scan range: Start 5 μm, stop -10 μm Number of averages: 1 Measurement begins after auto lamp

[0149] [Analysis conditions] Complement: Full Surface correction: Fourth order [Safc measurement conditions] Filter: Gaussian (short wavelength cutoff value λs: 50 [μm]) Analysis - ISOParam

[0150] [Measurement conditions for Smr1] Filter: Gaussian (short wavelength cutoff value λs: 2.6 [μm]) Filter: Gaussian (long wavelength cutoff value λc: 25 [μm]) High-pass image was set as the main. Analysis - ISOParam

[0151] [Retardation Re] The retardation Re of the substrate film of each antiglare film was measured using a two-dimensional birefringence evaluation system, "Photonic Lattice WPA-200" manufactured by Ryokosha Co., Ltd.

[0152] [Iridescent unevenness] Each antiglare film was attached to the display surface of an LCD, "JN-T280UHD-NS" manufactured by JAPANNEXT Co., Ltd. (resolution 4K (28 inches, 3840 dots x 2160 dots)). The LCD was driven to display a white screen, and the screen was viewed through a polarizing plate "PZ-2" manufactured by Kenis Co., Ltd., and the iridescent unevenness was visually confirmed. The iridescent unevenness at this time was evaluated using the following 5-point scale. The higher the evaluation value, the higher the evaluation. 5: Iridescent unevenness is not visible from any angle when the surface is viewed. 4: Slight iridescent unevenness is visible only when the surface is viewed from a specific angle. 3: Iridescent unevenness is visible only when the surface is viewed from a specific angle. 2: Slight iridescent unevenness is visible over the entire surface. 1: Iridescent unevenness is visible to the same extent as when there is no antiglare layer. The test results are shown in Tables 1 and 2.

[0153]

[0154]

[0155] As shown in Table 1, the surfaces 4a, 104a of the antiglare layers 4, 104 of Examples 1 to 6 were confirmed to have uneven shapes in which Safe was a value in the range of 0.02 or more when the short wavelength cutoff value λs was set to 50 μm, and Smr1 was a value in the range of 14% or more when the long wavelength cutoff value λc was set to 25 μm and the short wavelength cutoff value λs was set to 2.6 μm. Furthermore, it was confirmed that iridescent unevenness was well reduced in Examples 1 to 6. In contrast, it was confirmed that the Safe of the antiglare layer surfaces of Comparative Examples 1 to 5 was not a value in the range of 0.02 or more, and that the Smr1 of the antiglare layer surface of Comparative Example 6 was not a value in the range of 14% or more. Furthermore, it was confirmed that Comparative Examples 1 to 6 were more susceptible to iridescent unevenness than Examples 1 to 6.

[0156] Furthermore, as shown in Table 2, it was confirmed that in Examples 1, 7 to 13, the integrated value (D×Re) was within the range of Formula 1. It was also confirmed that in Examples 1, 7 to 13, rainbow unevenness was relatively well improved. In contrast, it was confirmed that in Comparative Example 7, although the antiglare layer was equivalent to that of Example 1, the integrated value (D×Re) was not within the range of Formula 1. It was also confirmed that in Comparative Example 7, rainbow unevenness was more likely to occur than in Examples 1, 7 to 13.

[0157] (Disclosure Items) Each of the following items discloses a preferred embodiment. [Item 1] An antiglare film comprising: a substrate film which is a biaxially stretched film having in-plane birefringence and which satisfies the relationship shown in Formula 1; and an antiglare layer disposed overlying the substrate film, wherein the surface of the antiglare layer opposite to the substrate film side has an uneven shape in which Safc, which is a fractal parameter when the short wavelength cutoff value λs is set to 50 μm, is a value in the range of 0.02 or more, and Smr1, when the long wavelength cutoff value λc is set to 25 μm and the short wavelength cutoff value λs is set to 2.6 μm, is a value in the range of 14% or more. [Formula 1] Substrate film thickness D (m) × retardation Re (m) ≧ 1.0 × 10 －１０ (m ２ )

[0158] According to the above configuration, the unevenness of the surface of the antiglare layer is set to the above-mentioned values ​​of Safc and Smr1, so that the unevenness is formed to have a distribution structure of steep unevenness with a high number density. This scatters light incident on the surface of the antiglare layer, and appropriately suppresses reflection of external light on the surface of the antiglare layer. In addition, an excellent antiglare effect is obtained.

[0159] Furthermore, by constructing an antiglare film to include an antiglare layer having the uneven surface and a substrate film that satisfies Formula 1, it is possible to construct the substrate film from a biaxially stretched film, thereby maintaining sufficient mechanical strength, and to realize an antiglare film that exhibits excellent antiglare effect and rainbow unevenness prevention effect at low cost.

[0160] [Item 2] The antiglare film according to Item 1, wherein the substrate film comprises a polyester film.

[0161] According to the above-mentioned configuration, an antiglare film having sufficient mechanical strength can be produced at a relatively low cost.

[0162] [Item 3] The antiglare film according to Item 1 or 2, wherein the Smr1 of the surface of the antiglare layer opposite to the substrate film side is a value in the range of 50% or less.

[0163] According to the above-mentioned configuration, for example, the ratio of convex portions in the uneven shape of the surface of the antiglare layer can be reduced, and the mechanical strength of the antiglare film can be easily maintained.

[0164] [Item 4] The antiglare film according to any one of Items 1 to 3, wherein the Safc is a value in the range of 1.0 or less.

[0165] According to the above-mentioned configuration, even small characters displayed on the display surface to which the anti-glare film is attached can be easily read, thereby achieving excellent anti-glare effects and image display performance.

[0166] [Item 5] The antiglare film according to any one of Items 1 to 4, wherein the substrate film thickness D is a value in the range of 50 μm to 125 μm.

[0167] According to the above configuration, by using a substrate film having a certain degree of substrate film thickness D, it is possible to facilitate the handling of materials during the production of the antiglare film and also to facilitate the realization of an antiglare film having excellent mechanical strength.

[0168] [Item 6] The antiglare film according to any one of Items 1 to 5, wherein the antiglare layer contains a plurality of resin components and has a phase-separated structure of the plurality of resin components.

[0169] According to the above-mentioned configuration, the phase separation structure can be used to form the uneven shape of the surface of the anti-glare layer so as to have a structure with steep peaks and high number density, thereby achieving an excellent anti-glare effect.

[0170] [Item 7] The antiglare film according to any one of Items 1 to 6, wherein the antiglare layer has a microparticle dispersion structure containing a matrix resin and a plurality of microparticles dispersed in the matrix resin.

[0171] According to the above-mentioned configuration, the surface of the anti-glare layer can be formed to have a sharp uneven shape with a high number density using a fine particle dispersion structure, thereby achieving an excellent anti-glare effect.

[0172] [Item 8] The antiglare film according to any one of Items 1 to 7, further comprising an antireflection layer disposed on the antiglare layer opposite to the substrate film side.

[0173] According to the above configuration, the optical properties of the antiglare film can be easily adjusted by using the low refractive index layer disposed on the antiglare layer.

[0174] [Item 9] An optical member comprising: the antiglare film according to any one of items 1 to 8; and a polarizing plate disposed on the antiglare film.

[0175] [Item 10] A display device comprising: the antiglare film according to any one of items 1 to 8; a polarizing plate disposed so as to be superimposed on the film; and a display element disposed so as to be superimposed on the antiglare film and the polarizing plate.

[0176] Each configuration and combination thereof in each embodiment is an example. Addition, omission, substitution, and other modifications of configurations are possible as appropriate without departing from the spirit of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the claims. Furthermore, each aspect disclosed herein can be combined with any other feature disclosed herein.

[0177] REFERENCE SIGNS LIST 1, 20 Display device 2, 102, 202, 302, 402 Antiglare film 3 Base film 4, 104 Antiglare layer 4a, 104a Surface of antiglare layer opposite to the base film side 6 Polarizing plate 9 Antireflection layer 10 Optical member 15 Display element 40 Matrix resin 41 Fine particles

Claims

1. An antiglare film comprising: a substrate film which is a biaxially stretched film having in-plane birefringence and which satisfies the relationship shown in formula 1; and an antiglare layer disposed on the substrate film, wherein the surface of the antiglare layer opposite to the substrate film has an uneven shape in which Safc, which is a fractal parameter when the short wavelength cutoff value λs is set to 50 μm, is a value in the range of 0.02 or more, and Smr1 when the long wavelength cutoff value λc is set to 25 μm and the short wavelength cutoff value λs is set to 2.6 μm is a value in the range of 14% or more. [Formula 1] Substrate film thickness D (m) × retardation Re (m) ≧ 1.0 × 10 －１０ (m ２ ) 2. The antiglare film according to claim 1, wherein the substrate film comprises a polyester film.

3. An antiglare film according to claim 1 or 2, wherein the Smr1 of the surface of the antiglare layer opposite to the substrate film side is a value in the range of 50% or less.

4. The antiglare film according to any one of claims 1 to 3, wherein the Safc is a value in the range of 1.0 or less.

5. The antiglare film according to any one of claims 1 to 4, wherein the substrate film thickness D is a value in the range of 50 µm or more and 125 µm or less.

6. The antiglare film according to any one of claims 1 to 5, wherein the antiglare layer contains a plurality of resin components and has a phase-separated structure of the plurality of resin components.

7. The antiglare film according to any one of claims 1 to 6, wherein the antiglare layer has a microparticle dispersion structure containing a matrix resin and a plurality of microparticles dispersed in the matrix resin.

8. The antiglare film according to any one of claims 1 to 7, further comprising an antireflection layer disposed on the antiglare layer opposite to the substrate film side.

9. An optical member comprising: the antiglare film according to any one of claims 1 to 8; and a polarizing plate disposed on the antiglare film.

10. A display device comprising: an antiglare film according to any one of claims 1 to 8; a polarizing plate disposed so as to be superimposed on said film; and a display element disposed so as to be superimposed on said antiglare film and said polarizing plate.

Images