Anti-glare film

Abstract

To provide an antiglare film which is hardly colored, has excellent antiglare properties, and can suppress glare of display.SOLUTION: An antiglare film comprises an antiglare layer which has a haze value in a range from 60% to 95%, an internal haze value in a range from 0.5% to 15.0% and in which the standard deviation of luminance distribution of a display is a value of 0 or more and 10 or less in a state of being mounted on the surface of the display.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an anti-glare film that prevents external light from reflecting onto the surface of a display. [Background technology]

[0002] An anti-glare film is, for example, a film having an anti-glare layer on which irregularities are formed on the surface by roughening, and is attached to the surface of a display to scatter ambient light and prevent reflections of ambient light onto the display surface.

[0003] Incidentally, when an anti-glare film is applied to the surface of a display with high-resolution pixels, the light from the display that passes through the anti-glare film may be refracted by the unevenness of the anti-glare layer's surface, or the pixels of the display may appear magnified due to the lens effect caused by the unevenness of the anti-glare layer's surface, resulting in glare on the display and making the image difficult to see.

[0004] Therefore, as disclosed in Patent Document 1, for example, there is a known method of suppressing display glare by dispersing relatively small particles in an anti-glare layer to form fine irregularities on the surface. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2009-109702 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, if fine particles are simply dispersed in the anti-glare layer, the anti-glare film may become discolored, for example, with a yellowish tint, potentially reducing the color reproduction accuracy of the display through the anti-glare film.

[0007] Therefore, the present invention aims to provide an anti-glare film that is difficult to color, has good anti-glare properties, and can suppress glare on displays. [Means for solving the problem]

[0008] To solve the above problems, an anti-glare film according to one aspect of the present invention comprises an anti-glare layer having a haze value in the range of 60% to 95%, an internal haze value in the range of 0.5% to 15.0%, and a standard deviation of the brightness distribution of the display when attached to the surface of the display that is between 0 and 10.

[0009] In the anti-glare layer of the anti-glare film having the above configuration, the internal haze value is suppressed to a value in the range of 0.5% to 15.0%, while the haze value is maintained in the range of 60% to 95% by the external haze value.

[0010] By configuring the anti-glare layer in this way, it is possible to adjust the external haze value by appropriately roughening the surface of the anti-glare layer without increasing the internal haze value of the anti-glare layer, thereby obtaining good anti-glare properties. For example, it is possible to suppress the wide-angle scattering of light incident on the anti-glare film by the fine particles in the anti-glare layer. Consequently, it is possible to prevent the anti-glare film from becoming discolored due to the wide-angle scattering of light of a predetermined wavelength incident on the anti-glare film (for example, the scattering of low-wavelength light such as blue light causing the anti-glare film to become yellowish).

[0011] Furthermore, the standard deviation of the display's brightness distribution indicates the degree of variation in bright spots on the display and serves as an objective indicator that allows for quantitative evaluation of the display's glare. Therefore, in the above configuration, by setting the standard deviation to a value within the range of 0 to 10, it is possible to suppress the display's glare more effectively while preventing discoloration of the anti-glare film.

[0012] L * a * b * b in the color system *The value may be in the range of 0 or more and 10 or less. Thus, the L of the antiglare film * a * b * By setting the b value in the color system, it is possible to preferably prevent the antiglare film from having a color tone. *

[0013] The antiglare layer may include a plurality of resin components and have a co-continuous phase structure formed by phase separation of the plurality of resin components. Thereby, while suppressing the internal haze value of the antiglare layer, the haze value of the antiglare layer is appropriately set by forming irregularities on the surface of the antiglare layer due to the co-continuous phase structure, and it is easy to suppress the glare of the display.

[0014]

[0013] The antiglare layer may include a matrix resin and a plurality of fine particles dispersed in the matrix resin, and the refractive index difference between the fine particles and the matrix resin may be a value in the range of 0 or more and 0.2 or less.

[0015] Thus, by setting the refractive index difference between the matrix resin and the fine particles within a predetermined range and dispersing a plurality of fine particles in the matrix resin, it is possible to suppress the glare of the display while ensuring good antiglare properties, and it is possible to preferably suppress the wide-angle scattering of light incident on the antiglare film due to the refractive index difference between the matrix resin and the fine particles, and prevent the coloring of the antiglare film.

[0016] The ratio G2 / G1 of the weight G1 of the matrix resin of the antiglare layer to the total weight G2 of the plurality of fine particles contained in the antiglare layer may be a value in the range of 0.07 or more and 0.20 or less. Thereby, it is possible to preferably manufacture the above-described antiglare film having an antiglare layer having a structure in which a plurality of fine particles are dispersed in a matrix resin.

Advantages of the Invention

[0017] According to the present invention, it is possible to provide an antiglare film that is difficult to be colored, has good antiglare properties, and can suppress the glare of a display.

Brief Description of the Drawings

[0018] [Figure 1] This is a cross-sectional view showing the configuration of the anti-glare film according to the first embodiment. [Figure 2] This figure shows a method for manufacturing an anti-glare film according to the third embodiment. [Figure 3] This is a schematic diagram of a glare inspection machine. [Modes for carrying out the invention]

[0019] Hereinafter, each embodiment of the present invention will be described with reference to the figures. (First Embodiment)

[0020] Figure 1 is a cross-sectional view showing the configuration of the anti-glare film 1 according to the first embodiment. The anti-glare film 1 is attached to the surface of the display 16a of the display device 16 (see Figure 3). The anti-glare film 1 comprises a base film 2, an anti-glare layer 3, and an adhesive layer 4.

[0021] The base film 2 is placed between the display 16a and the anti-glare layer 3 and supports the anti-glare layer 3. The adhesive layer 4 is placed between the display 16a and the base film 2 and fixes the anti-glare film 1 to the surface of the display 16a. The adhesive layer 4 is, for example, an optical adhesive and is made of a material that does not easily affect the optical properties of the anti-glare film 1.

[0022] The anti-glare layer 3 is formed on at least one surface of the base film 2. The anti-glare layer 3 imparts anti-glare properties to the anti-glare film 1 and scatters and reflects ambient light to prevent reflection of ambient light onto the surface of the display 16a. The anti-glare layer 3 also functions as a hard coat (HC) layer that protects the surface of the display 16a. The anti-glare layer 3 includes, as an example, a plurality of phase-separable resin components.

[0023] The anti-glare layer 3 is set to a haze value in the range of 60% to 95%, and to an internal haze value in the range of 0.5% to 15.0%.

[0024] The haze value can be appropriately set within the above range, but a value in the range of 70% or more and 85% or less is more desirable. Also, the internal haze value can be appropriately set within the above range, but a value in the range of 0.5% or more and 8.0% or less is more desirable.

[0025] The haze value of this embodiment is a value measured by a method conforming to JIS K7136. The external haze value corresponds to the value obtained by subtracting the internal haze value from the haze value. The internal haze value can be measured by coating the antiglare layer 3 with a resin layer or the like, or by laminating a smooth transparent film to the antiglare layer 3 through a transparent adhesive layer to flatten the surface of the antiglare layer 3 and then measuring the haze value.

[0026] Thus, in the antiglare layer 3 of the antiglare film 1, while suppressing the internal haze value to a value in the range of 0.5% or more and 15.0% or less, the haze value is maintained at a value in the range of 60% or more and 95% or less by the external haze value. By configuring the antiglare layer 3 in this way, even without increasing the internal haze value of the antiglare layer 3, the surface of the antiglare layer can be appropriately roughened to adjust the external haze value, and good antiglare properties can be obtained. Therefore, for example, it is possible to suppress the light incident on the antiglare film from being scattered at a wide angle by the fine particles in the antiglare layer. Accordingly, it is possible to prevent the light of a predetermined wavelength incident on the antiglare film 1 from being scattered at a wide angle and the antiglare film 1 from being colored (for example, the antiglare film is colored with a yellowish tint by the scattering of low-wavelength light such as blue light).

[0027] Also, the antiglare film 1 has an L * a * b * value of b in the L * a * b * value of b in the a * b * color system set in the range of 0 or more and 10 or less. By setting the value of b in the L

[0028] Furthermore, as will be described in detail later, the anti-glare layer 3 contains multiple resin components and has a co-continuous phase structure formed by the phase separation of these multiple resin components. This allows for the appropriate setting of the haze value of the anti-glare layer 3 by suppressing the internal haze value of the anti-glare layer 3 while forming irregularities on the surface of the anti-glare layer 3 with the co-continuous phase structure, making it easier to suppress glare from the display 16a.

[0029] Furthermore, the anti-glare film 1 is set so that the standard deviation of the brightness distribution of the display 16a (hereinafter also referred to as the glare value) when attached to the surface of the display 16a is within the range of 0 to 10.

[0030] Here, the standard deviation value of the luminance distribution of the display 16a indicates the degree of variation in bright spots on the display 16a and serves as an objective indicator that can quantitatively evaluate the glare of the display 16a. Therefore, by setting the standard deviation value to a value in the range of 0 to 10, the glare of the display 16a can be suppressed more effectively while preventing discoloration of the anti-glare film 1. Specific examples of the base film 2 and the anti-glare layer 3 will be described below.

[0031] Examples of materials for the base film 2 include glass, ceramics, and resin. The same resin as the material for the anti-glare layer 3 can be used as the resin. Preferred materials for the base film 2 include transparent polymers, such as cellulose derivatives (cellulose triacetate (TAC), cellulose diacetate, and other cellulose acetates), polyester resins (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyarylate resins, etc.), polysulfone resins (polysulfone, polyethersulfone (PES), etc.), and polyetherketone resins (polyetherketone (PEK), polyether Examples include ether ketone (PEEK, etc.), polycarbonate resins (PC), polyolefin resins (polyethylene, polypropylene, etc.), cyclic polyolefin resins (such as JSR Corporation's "ARTON" film and Zeon Corporation's "ZEONEX" film), 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).

[0032] The base film 2 may be uniaxially or biaxially stretched, but it is preferably optically isotropic and has a low refractive index. An example of an optically isotropic base film 2 is an unstretched film.

[0033] The thickness of the base film 2 can be set as appropriate, but it is preferable that it be in the range of 5 μm to 2000 μm, more preferably in the range of 15 μm to 1000 μm, and even more preferably in the range of 20 μm to 500 μm.

[0034] [Structure of the anti-glare layer] The anti-glare layer 3 of the first embodiment has a phase separation structure of multiple resin components. As an example, the anti-glare layer 3 has multiple elongated (string-like or linear) protrusions formed on its surface by the phase separation structure of multiple resin components. The elongated protrusions are branched and form a dense co-continuous phase structure.

[0035] The anti-glare layer 3 exhibits anti-glare properties through multiple elongated protrusions and recesses located between adjacent elongated protrusions. By incorporating such an anti-glare layer 3, the anti-glare film 1 achieves an excellent balance between haze value and transmitted image clarity (image quality). The surface of the anti-glare layer 3 has a mesh-like structure, or in other words, a series of irregular loop structures that are continuous or partially missing, due to the elongated protrusions being formed in a roughly mesh-like pattern.

[0036] The surface of the anti-glare layer 3 is formed with the above-described structure, which prevents the formation of lens-shaped (island-shaped) protrusions. Therefore, light from the display 16a that passes through the anti-glare layer 3 is prevented from being refracted by the irregularities on the surface of the anti-glare layer 3, and the pixels of the display 16a are prevented from appearing magnified due to the lens effect caused by the irregularities on the surface of the anti-glare layer 3, thereby suppressing the glare of the display 16a. As a result, even when the anti-glare film 1 is attached to a display 16a with high-resolution pixels, the glare of the display 16a can be highly suppressed while maintaining anti-glare properties, and blurring of text and images can also be suppressed.

[0037] The multiple elongated protrusions may be independent of each other or connected. The phase separation structure of the anti-glare layer 3 is formed by spinodal decomposition (wet spinodal decomposition) from the liquid phase using the solution that will be the raw material for the anti-glare layer 3, as will be described later. For details of the anti-glare layer 3, see, for example, the description in Japanese Patent Application No. 2012-231496.

[0038] [Material of the anti-glare layer] The multiple resin components contained in the anti-glare layer 3 can be phase-separable, but from the viewpoint of obtaining an anti-glare layer 3 that has elongated protrusions and high scratch resistance, it is preferable that it contains a polymer and a curable resin.

[0039] Examples of polymers included in the anti-glare layer 3 include thermoplastic resins. Examples of thermoplastic resins include styrene resins, (meth)acrylic resins, organic acid vinyl ester resins, vinyl ether resins, halogen-containing resins, olefin resins (including alicyclic olefin resins), polycarbonate resins, polyester resins, polyamide resins, thermoplastic polyurethane resins, polysulfone resins (polyethersulfone, polysulfone, etc.), polyphenylene ether resins (polymers of 2,6-xylenol, etc.), cellulose derivatives (cellulose esters, cellulose carbamates, cellulose ethers, etc.), silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubber or elastomers (diene rubbers such as polybutadiene and polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic rubber, urethane rubber, silicone rubber, etc.). These thermoplastic resins can be used individually or in combination of two or more types.

[0040] Examples of polymers include those having functional groups that participate in the curing reaction, or functional groups that react with curable compounds. These polymers may have functional groups in their main chain or side chains.

[0041] The aforementioned functional groups include condensing groups and reactive groups (e.g., hydroxyl groups, acid anhydride groups, carboxyl groups, amino or imino groups, epoxy groups, glycidyl groups, isocyanate groups, etc.), and polymerizable groups (e.g., vinyl, propenyl, isopropenyl, butenyl, allyl groups, etc.). 2-6 C groups such as alkenyl groups, ethynyl, propynyl, and butynyl groups. 2-6 C such as alkynyl groups and vinylidene groups. 2-6 Examples of functional groups include alkenylidene groups, or groups having polymerizable groups such as (meth)acryloyl groups, etc.). Of these functional groups, polymerizable groups are preferred.

[0042] Furthermore, the anti-glare layer 3 may contain multiple types of polymers. Each of these polymers may be phase-separable by spinodal decomposition from the liquid phase, or they may be incompatible with each other. The combination of the first polymer and the second polymer contained in the multiple types of polymers is not particularly limited, but those that are incompatible with each other near the processing temperature can be used.

[0043] For example, if the first polymer is a styrene-based resin (polystyrene, styrene-acrylonitrile copolymer, etc.), the second polymer may be a cellulose derivative (e.g., cellulose esters such as cellulose acetate propionate), a (meth)acrylic resin (polymethyl methacrylate, etc.), an alicyclic olefin resin (polymers with norbornene as a monomer, etc.), a polycarbonate resin, or a polyester resin (polyC 2-4 Examples include alkylene arylate-based copolyesters, etc.

[0044] Furthermore, for example, if the first polymer is a cellulose derivative (e.g., cellulose esters such as cellulose acetate propionate), the second polymer may be a styrene resin (polystyrene, styrene-acrylonitrile copolymer, etc.), a (meth)acrylic resin, an alicyclic olefin resin (polymer with norbornene as a monomer, etc.), a polycarbonate resin, or a polyester resin (poly-C 2-4 Examples include alkylene arylate-based copolyesters, etc.

[0045] Multiple types of polymers include at least cellulose esters (e.g., cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, etc.). 2-4 It may contain alkylcarboxylic acid esters.

[0046] Here, the phase separation structure of the anti-glare layer 3 is fixed when the precursor of the curable resin contained in multiple resin components hardens due to active energy rays (ultraviolet rays or electron beams, etc.) or heat during the manufacturing of the anti-glare layer 3. Furthermore, this curable resin imparts scratch resistance and durability to the anti-glare layer 3.

[0047] From the viewpoint of obtaining scratch resistance for the anti-glare layer 3, it is preferable that at least one polymer included in the multiple types of polymers is a polymer having a functional group in its side chain that can react with a curable resin precursor. In addition to the two mutually immiscible polymers described above, thermoplastic resins and other polymers may be included as polymers that form a phase separation structure. The weight ratio M1 / M2 of the weight M1 of the first polymer to the weight M2 of the second polymer, and the glass transition temperature of the polymer can be set as appropriate.

[0048] Examples of curable resin precursors include curable compounds that have functional groups that react to active energy rays (such as ultraviolet rays or electron beams) or heat, and which harden or crosslink to form a resin (particularly a cured resin or a crosslinked resin) through these functional groups.

[0049] Examples of such compounds include thermosetting compounds or thermosetting resins (low molecular weight compounds having epoxy groups, polymerizable groups, isocyanate groups, alkoxysilyl groups, silanol groups, etc. (e.g., epoxy resins, unsaturated polyester resins, urethane resins, silicone resins, etc.)), and photocurable (ionizing radiation curable) compounds that harden with ultraviolet light or electron beams (UV-curable compounds such as photocurable monomers and oligomers).

[0050] Examples of preferred curable resin precursors include photocurable compounds that cure quickly with ultraviolet light or electron beams. Of these, ultraviolet-curable compounds are particularly practical. To improve resistance such as scratch resistance, the photocurable compound preferably has two or more polymerizable unsaturated bonds in its molecule (preferably 2 to 15, more preferably about 4 to 10). Specifically, the photocurable compound is preferably epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, silicone (meth)acrylate, or a polyfunctional monomer having at least two polymerizable unsaturated bonds.

[0051] Curable resin precursors may contain curing agents depending on their type. For example, thermosetting resin precursors may contain curing agents such as amines and polycarboxylic acids, and photocurable resin precursors may contain photopolymerization initiators. Examples of photopolymerization initiators include conventional components such as acetophenones or propiophenones, benzyl compounds, benzoins, benzophenones, thioxanthones, and acylphosphine oxides.

[0052] Furthermore, the curable resin precursor may contain a curing accelerator. For example, the photocurable resin precursor may contain a photocuring accelerator, such as tertiary amines (dialkylaminobenzoic acid esters, etc.) or phosphine-based photopolymerization accelerators.

[0053] In the manufacturing process of the anti-glare layer 3, at least two components from the polymer and curable resin precursor contained in the solution that serves as the raw material for the anti-glare layer 3 are used in a combination that undergoes phase separation from each other near the processing temperature. Examples of combinations to undergo phase separation include (a) a combination in which multiple types of polymers undergo phase separation in an immiscible manner, (b) a combination in which a polymer and a curable resin precursor undergo phase separation in an immiscible manner, or (c) a combination in which multiple curable resin precursors undergo phase separation in an immiscible manner. Of these combinations, (a) a combination of multiple types of polymers and (b) a combination of polymer and a curable resin precursor are usually preferred, with (a) a combination of multiple types of polymers being particularly preferred.

[0054] Here, typically, the polymer and the cured resin or crosslinked resin produced by the curing of the curable resin precursor have different refractive indices. Also, typically, the refractive indices of multiple types of polymers (the first polymer and the second polymer) also differ from each other. The refractive index difference between the polymer and the cured resin or crosslinked resin, and the refractive index difference between multiple types of polymers (the first polymer and the second polymer), is preferably in the range of 0 to 0.04, and more preferably in the range of 0 to 0.02.

[0055] The anti-glare layer 3 may contain multiple fine particles (fillers) dispersed in the matrix resin. The fine particles may be either organic or inorganic, and the multiple fine particles may consist of multiple types of fine particles.

[0056] Examples of organic microparticles include cross-linked acrylic particles and cross-linked styrene particles. Examples of inorganic microparticles include silica particles and alumina particles. The refractive index difference between the microparticles contained in the anti-glare layer 3 and the matrix resin can be set to a value in the range of 0 to 0.2, for example. It is more desirable that this refractive index difference be in the range of 0 to 0.15, and even more desirable that it be in the range of 0 to 0.07.

[0057] 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 5.0 μm, for example. It is more desirable that this average particle size be in the range of 0.5 μm to 4.0 μm, and even more desirable that it be in the range of 1.0 μm to 3.0 μm.

[0058] Note that the average particle size referred to here is the 50% volume-average particle size in the Coulter counter method (the same applies to the average particle size mentioned below). The particles may be solid or hollow. Care should be taken as if the average particle size is too small, anti-glare properties may not be achieved, and if it is too large, display glare may increase.

[0059] The thickness of the anti-glare layer 3 can be set as appropriate, but it is preferable that it be in the range of 0.3 μm to 20 μm, more preferably in the range of 1 μm to 15 μm, and even more preferably in the range of 1 μm to 10 μm. Typically, it can be set to a value in the range of 2 μm to 10 μm (especially in the range of 3 μm to 7 μm).

[0060] In addition, an anti-glare film can be constructed by omitting the base film 2, but in this case, the thickness of the anti-glare layer 3 is preferably in the range of 1 μm to 100 μm, and more preferably in the range of 3 μm to 50 μm.

[0061] The anti-glare layer 3 may contain conventional additives, such as organic or inorganic particles, stabilizers (antioxidants, UV absorbers, etc.), surfactants, water-soluble polymers, fillers, crosslinking agents, coupling agents, colorants, flame retardants, lubricants, waxes, preservatives, viscosity modifiers, thickeners, leveling agents, defoaming agents, etc., to the extent that they do not impair the optical properties.

[0062] The method for manufacturing the anti-glare film in the first embodiment includes, as an example, a preparation step of preparing a solution (hereinafter also simply referred to as the solution) that will be the raw material for the anti-glare layer 3; a forming step of applying the solution prepared in the preparation step to the surface of a predetermined support (in this embodiment, a base film 2), evaporating the solvent in the solution, and forming a phase-separated structure by spinodal decomposition from the liquid phase; and a curing step of curing a curable resin precursor after the forming step.

[0063] [Preparation process] In the preparation step, a solution is prepared containing a solvent and a resin composition for constituting the anti-glare layer 3. The solvent can be selected according to the type and solubility of the polymer and curable resin precursor contained in the anti-glare layer 3 as described above. The solvent should be capable of uniformly dissolving at least the solid components (multiple types of polymers and curable resin precursors, reaction initiators, and other additives).

[0064] Examples of solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc. Mixed solvents may also be used.

[0065] The resin composition is preferably a composition comprising the thermoplastic resin, a photocurable compound, a photopolymerization initiator, the thermoplastic resin, and the photocurable compound. Alternatively, the resin composition is preferably a composition comprising the multiple types of mutually immiscible polymers, a photocurable compound, and a photopolymerization initiator.

[0066] The concentration of solutes in the solution (polymers and curable resin precursors, reaction initiators, and other additives) can be adjusted within a range that allows for phase separation of multiple resin components and does not impair the flowability or coating properties of the solution.

[0067] Here, the haze value of the anti-glare layer 3 and the internal haze value, and the L of the anti-glare film 1. * a * b * b in the color system * The standard deviation of the brightness distribution (glare value) of a display 16a with an anti-glare film 1 attached to its surface can change depending on the combination and weight ratio of the resin composition in the solution, or the construction conditions of the preparation process, formation process, and curing process. Therefore, by forming an anti-glare layer by changing each condition and measuring and understanding the physical properties of the resulting anti-glare layer in advance, an anti-glare film with the desired physical properties can be obtained.

[0068] [Formation process] In the forming process, the solution prepared in the preparation process is cast or coated onto the surface of a support (in this case, a base film 2 as an example). Examples of conventional methods for casting or coating the solution include spray, spinner, roll coater, air knife coater, blade coater, rod coater, reverse coater, bar coater, comma coater, dip, dip-squeeze coater, die coater, gravure coater, microgravure coater, silkscreen coater, etc.

[0069] The solvent is removed from the solution cast or coated onto the surface of the support by evaporation. This evaporation process concentrates the solution, leading to phase separation of multiple resin components from the liquid phase via spinodal decomposition, forming a phase-separated structure with relatively regular interphase distances (pitch or mesh diameter). The co-continuous phase structure of the elongated convex portions can be formed by setting drying conditions and formulations that increase the melt-fluidity of the resin components after solvent evaporation to a certain extent.

[0070] Evaporation of the solvent is preferably carried out by heating and drying, as this facilitates the formation of elongated protrusions on the surface of the anti-glare layer 3. Care should be taken as if the drying temperature is too low or the drying time is too short, the heat supplied to the resin component will be insufficient, reducing the melt-fluidity of the resin component and making it difficult to form elongated protrusions.

[0071] On the other hand, if the drying temperature is too high or the drying time is too long, the elongated protrusions that have been formed may flow and their height may decrease, but the structure of the elongated protrusions will be maintained. Therefore, drying temperature and drying time can be used as a means to adjust the anti-glare properties and slipperiness of the anti-glare layer 3 by changing the height of the elongated protrusions. In addition, in the formation process, a co-continuous phase structure in which phase-separated structures are connected can be formed by increasing the evaporation temperature of the solvent or by using a low-viscosity component in the resin component.

[0072] As phase separation progresses due to spinodal decomposition of multiple resin components from the liquid phase, a co-continuous phase structure is formed and coarsens, causing the continuous phase to become discontinuous, and a droplet phase structure (sea-island structure of independent phases such as spherical, sphere-like, disc-like, or ellipsoidal) is formed. Depending on the degree of phase separation, intermediate structures between the co-continuous phase structure and the droplet phase structure (phase structures in the transition from the co-continuous phase to the droplet phase) can also be formed. After solvent removal, a layer with fine irregularities is formed on the surface.

[0073] In this way, by forming fine irregularities on the layer surface through phase separation, the haze value of the anti-glare layer 3 can be adjusted without dispersing fine particles within the anti-glare layer 3. Furthermore, since it is not necessary to disperse fine particles within the anti-glare layer 3, it is possible to easily adjust the haze value of the anti-glare layer 3 while suppressing the internal haze value compared to the external haze value. It should be noted that it is also possible to form an anti-glare layer 3 containing fine particles by adding fine particles to the solution during the preparation process, but in this case, caution is required because if the refractive index difference between the matrix resin in the anti-glare layer 3 and the fine particles is large, the anti-glare layer 3 may become discolored.

[0074] [Curing process] In the curing process, the curable resin precursor in the solution is cured to immobilize the phase-separated structure formed in the formation process, thereby forming the anti-glare layer 3. The curing of the curable resin precursor is performed by heating, irradiation with active energy rays, or a combination of these methods, depending on the type of curable resin precursor. The active energy rays used for irradiation are selected according to the type of photocurable component, etc.

[0075] Irradiation with active energy rays may be carried out in an inert gas atmosphere. When the active energy rays are ultraviolet rays, a far-ultraviolet lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp, a laser light source (such as a helium-cadmium laser or an excimer laser) can be used as the light source.

[0076] When forming the adhesive layer 4, after preparing a solution containing an adhesive component, the adhesive layer 4 can be formed by applying and drying the solution to the other surface of the base film 2 using a conventional method, such as the casting method or coating method described above in the formation process.

[0077] By going through the above steps, the anti-glare film 1 of the first embodiment is manufactured. When a peelable support is used as the support, an anti-glare film composed only of the anti-glare layer 3 can be obtained by peeling the anti-glare layer 3 from the support. When a non-peelable support (preferably a transparent support such as the base film 2) is used as the support, an anti-glare film 1 having a laminated structure of the support (base film 2) and the anti-glare layer 3 can be obtained.

[0078] One possible method to suppress the glare of the display 16a is to reduce the surface irregularities of the anti-glare layer, but this may reduce the anti-glare properties of the anti-glare film. However, by not only reducing the irregularities of the anti-glare layer but also increasing the slope of the irregularities and making them steeper, as well as increasing the number of irregularities, it is possible to improve the anti-glare properties while suppressing the glare of the display.

[0079] In the first embodiment, such irregularities can be formed on the anti-glare layer by the spinodal decomposition described above, but such irregularities can also be formed on the anti-glare layer by other methods. For example, even when multiple fine particles are used to form the surface irregularities of the anti-glare layer, as in the second embodiment, by selecting materials that increase the repulsive interaction between the fine particles and other resins and solvents during the formation of the anti-glare layer, appropriate aggregation of the fine particles can be induced, and a distribution structure of steep and number-density irregularities can be formed on the anti-glare layer. Therefore, the anti-glare layers of other embodiments will be described below, focusing on the differences from the first embodiment.

[0080] (Second Embodiment) The anti-glare layer of the anti-glare film according to the second embodiment includes a matrix resin and a plurality of fine particles dispersed in the matrix resin. The fine particles are formed in a spherical shape, but are not limited to this, and may be formed in a substantially spherical or ellipsoidal shape. The fine particles are formed in a solid shape, but may also be formed in a hollow shape. If the fine particles are formed in a hollow shape, the hollow portion of the fine particles may be filled with air or other gas. The anti-glare layer may contain individual fine particles dispersed as primary particles, or it may contain a plurality of secondary particles formed by the aggregation of a plurality of fine particles.

[0081] The refractive index difference between the matrix resin and the fine particles is set to a value in the range of 0 to 0.2. More preferably, this refractive index difference is in the range of 0 to 0.15, and even more preferably, in the range of 0 to 0.07.

[0082] The fine particles are set to have an average particle size within the range of 0.5 μm to 5.0 μm. It is more desirable that the average particle size of the fine particles be within the range of 0.5 μm to 4.0 μm, and even more preferable that it be within the range of 1.0 μm to 3.0 μm.

[0083] Furthermore, it is desirable for the variation in particle size of the fine particles to be small. For example, in the particle size distribution of the fine particles contained in the anti-glare layer, it is desirable that the average particle size of 50% or more by weight of the fine particles contained in the anti-glare layer is kept within a variation of 1.0 μm or less.

[0084] In this way, by using fine particles whose particle size is relatively uniform and whose average particle size is set within the above range, a uniform and appropriate unevenness is formed on the surface of the anti-glare layer. This makes it possible to suppress glare from the display 16a while ensuring anti-glare properties. Furthermore, by setting the refractive index difference between the matrix resin and the fine particles within the above range, it is possible to prevent light of a predetermined wavelength that enters the anti-glare film from being scattered at a wide angle and causing the anti-glare film to become discolored.

[0085] The ratio of the weight of the matrix resin in the anti-glare layer to the total weight of the multiple fine particles can be set as appropriate. In this embodiment, the ratio G2 / G1 of the weight G1 of the matrix resin in the anti-glare layer to the total weight G2 of the multiple fine particles contained in the anti-glare layer is set to a value in the range of 0.07 to 0.20. It is desirable that the ratio G2 / G1 be in the range of 0.1 to 0.20, and more preferably in the range of 0.12 to 0.2.

[0086] The fine particles dispersed in the matrix resin may be inorganic or organic, but those with good transparency are preferred. Examples of organic fine particles include plastic beads. Examples of plastic beads include styrene beads (refractive index 1.59), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), acrylic-styrene beads (refractive index 1.54), polycarbonate beads, polyethylene beads, etc. Styrene beads may be cross-linked styrene beads, and acrylic beads may be cross-linked acrylic beads. It is desirable that the plastic beads have hydrophobic groups on their surface. Examples of such plastic beads include styrene beads.

[0087] Examples of matrix resins include at least one of the following: a photocurable resin that hardens with active energy rays, a solvent-drying resin that hardens by the drying of a solvent added during coating, and a thermosetting resin.

[0088] Examples of photocurable resins include those having acrylate-based functional groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, oligomers such as (meth)arylates of polyfunctional compounds like polyhydric alcohols, prepolymers, and reactive diluents.

[0089] Specific examples of these include monofunctional monomers such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene, and N-vinylpyrrolidone, as well as polyfunctional monomers such as polymethylolpropane tri(meth)acrylate, hexanediol (meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate.

[0090] When the photocurable resin is an ultraviolet-curable resin, it is preferable to use a photopolymerization initiator. Examples of photopolymerization initiators include acetophenones, benzophenones, Michler-benzoyl benzoate, α-amyloxime esters, tetramethylthiuram monosulfide, and thioxanthones. It is also preferable to use a photosensitizer mixed with the photocurable resin. Examples of photosensitizers include n-butylamine, triethylamine, and poly-n-butylphosphine.

[0091] Examples of solvent-drying resins include well-known thermoplastic resins. Examples of these thermoplastic resins include styrene resins, (meth)acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins, cellulose derivatives, silicone resins, and rubber or elastomers. As solvent-drying resins, those that are soluble in organic solvents and have particularly excellent moldability, film-forming properties, transparency, and weather resistance are desirable. Examples of such solvent-drying resins include styrene resins, (meth)acrylic resins, alicyclic olefin resins, polyester resins, and cellulose derivatives (cellulose esters, etc.).

[0092] Here, if the material of the base film 2 is a cellulose-based resin such as triacetylcellulose (TAC), a cellulose-based resin can be used as an example of a thermoplastic resin used in the solvent-drying resin. Examples of cellulose-based resins include cellulose derivatives such as nitrocellulose, acetylcellulose, acetylbutylcellulose, ethylcellulose, methylcellulose, cellulose acetate propionate, and ethyl hydroxyethylcellulose. By using a cellulose-based resin as the solvent-drying resin, the base film 2 and the anti-glare layer 3 can be adhered well, and an anti-glare film 1 with excellent transparency can be obtained.

[0093] Other examples of solvent-drying resins include vinyl resins, acetal resins, acrylic resins, polystyrene resins, polyamide resins, and polycarbonate resins.

[0094] Examples of thermosetting resins include phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, unsaturated polyester resins, polyurethane resins, epoxy resins, aminoalkyd resins, melamine-urea cocondensation resins, silicon resins, and polysiloxane resins. When a thermosetting resin is used as the matrix resin, at least one of the following may be used in combination: a curing agent such as a crosslinking agent or polymerization initiator, a polymerization accelerator, a solvent, and a viscosity modifier.

[0095] The method for manufacturing the anti-glare film in the second embodiment includes, as an example, a preparation step of preparing a solution to be used as a raw material for the anti-glare layer 3, a coating step of applying the solution prepared in the preparation step to the surface of a predetermined support (a base film 2 in this embodiment), and a curing step of curing the resin in the coated solution.

[0096] [Preparation process] In the preparation step, a solution is prepared containing a solvent, a resin composition for constituting the anti-glare layer, and fine particles. Examples of solvents include at least one of the following: alcohols (isopropyl alcohol, methanol, ethanol, etc.), ketones (methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), halogenated hydrocarbons, and aromatic hydrocarbons (toluene, xylene, etc.). A known leveling agent may be added to the solution. For example, by using a fluorine-based or silicone-based leveling agent, good scratch resistance can be imparted to the anti-glare layer.

[0097] [Coating / curing process] In the coating step, the solution prepared in the preparation step is cast or coated onto the surface of a support (in this case, a base film 2 as an example) in the same manner as in the first embodiment. The solvent is removed from the solution cast or coated onto the surface of the support by evaporation through drying.

[0098] If the matrix resin is a photocurable resin, a curing process using ultraviolet light or electron beam is performed after the coating process. Examples of ultraviolet light sources include various mercury lamps, ultraviolet carbon arc lamps, black lights, and metal halide lamps. Examples of ultraviolet wavelength ranges include, for example, the range of 190 nm to 380 nm.

[0099] Examples of electron sources include well-known electron beam accelerators. Specifically, examples include various types of electron beam accelerators such as Van de Graaff type, Cockcroft-Walton type, resonant transformer type, isolated core transformer type, linear type, dynamitron type, and high-frequency type.

[0100] As the matrix resin contained in the solution hardens, the positions of the microparticles within the matrix resin are fixed. As a result, multiple microparticles are dispersed within the matrix resin, forming an anti-glare layer with a structure in which irregularities are formed on the surface by the microparticles.

[0101] According to the anti-glare film of the second embodiment, by setting the refractive index difference between the matrix resin and the fine particles within a predetermined range and dispersing a plurality of fine particles in the matrix resin, it is possible to suppress glare of the display 16a while ensuring good anti-glare properties. Furthermore, the scattering of light incident on the anti-glare film at a wide angle due to the refractive index difference between the matrix resin and the fine particles can be effectively suppressed, and discoloration of the anti-glare film can be prevented.

[0102] Furthermore, since the ratio G2 / G1 is set to a value in the range of 0.07 to 0.15, it is possible to successfully manufacture an anti-glare film having an anti-glare layer in which multiple fine particles are dispersed in the matrix resin.

[0103] (Third embodiment) The anti-glare layer 33 of the anti-glare film according to the third embodiment has a structure in which an uneven shape is formed on the surface opposite to the base film side. The anti-glare layer 33 is composed of a resin layer. This resin layer is, for example, composed of the same material as the matrix resin of the second embodiment.

[0104] Specifically, the anti-glare film according to the third embodiment is manufactured by forming a coating layer containing a curable resin on a base film, shaping the surface of this coating layer into an uneven form, and then curing the coating layer. Figure 2 shows a diagram illustrating the manufacturing method of the anti-glare film according to the third embodiment. In the example in Figure 2, an ultraviolet-curable resin is used as the curable resin.

[0105] As shown in Figure 2, in this manufacturing method, the base film 20a is unwound from an unwinding roll (not shown) and conveyed in a predetermined direction. The downstream end of the base film 20a in the conveying direction is inserted through the nip point N1 of a pair of rolls 21 and 22.

[0106] A UV-curing resin precursor is applied to the circumferential surface of roll 22 from the circumferential surface of roll 23, which is pivotally supported adjacent to roll 22. As the base film 20a passes through the nip point N1, this UV-curing resin precursor is applied to one side of the base film 20a.

[0107] The layer of ultraviolet-curable resin precursor applied to the base film 20a (hereinafter referred to as the coating layer) is pressed together with the base film 20a at the nip points of the rolls 21 and 24. Roll 24 is a roll-shaped mold (embossing roll) with fine irregularities formed on its circumferential surface, and as it passes through the nip point N2 of rolls 21 and 24, it transfers the irregular shape to the surface of the coating layer.

[0108] The coated layer, on which the surface irregularities have been transferred by the roll 24, is cured by ultraviolet light irradiated from the ultraviolet lamp 26 located below the rolls 21 and 24. This forms the anti-glare layer 33. The anti-glare film produced in this way is released from the roll 24 by the roll 25, which is pivotally supported adjacent to the roll 24, and conveyed in a predetermined direction.

[0109] Here, the uneven surface of the roll 24 is formed by impacting it with blast particles of a predetermined size using a blasting method, and the shape of the uneven surface formed on the coating layer of the anti-glare film can be adjusted by adjusting the blast particle size.

[0110] The base film 20a can preferably be PET (polyethylene terephthalate) film, TAC (triacetylcellulose) film, COP (cycloolefin polymer) film, acrylic resin film, or polycarbonate resin film.

[0111] Thus, the method for producing an anti-glare film according to the third embodiment includes the steps of: (a) applying a curable resin precursor to a base film; (b) creating a roll-shaped mold having an uneven surface by impacting it with blast particles; (c) using this roll-shaped mold to transfer the uneven surface to the surface of the curable resin precursor applied to the base film; and (d) curing the curable resin precursor on which the uneven surface has been transferred to form an anti-glare layer having an uneven surface.

[0112] The average particle size of the blast particles used in step (b) can be set as appropriate, but as an example, it can be set to a value in the range of 10 μm to 50 μm. A value in the range of 20 μm to 45 μm is more preferable, and a value in the range of 30 μm to 40 μm is even more preferable. This results in an anti-glare layer 33 with an uneven surface.

[0113] In the third embodiment, the mold used may not be a roll-shaped mold, but rather a plate-shaped mold (embossed plate), for example. Alternatively, the anti-glare layer 33 may be formed by forming a coating layer (resin layer) on one side of the base film, then shaping the surface of the coating layer with a mold, and curing the coating layer. In the above example, the coating layer was cured after shaping its surface, but the shaping and curing of the coating layer may be performed in parallel.

[0114] Examples of mold materials include metal, plastic, and wood. A coating may be applied to the contact surface of the mold with the coating layer to improve the durability (wear resistance) of the mold. Examples of blast particle materials include metal, silica, alumina, and glass. The blast particles can be impacted onto the mold surface, for example, by the pressure of a gas or liquid. Furthermore, if the curing resin precursor is electron beam curing type, an electron beam source such as an electron beam accelerator can be used instead of the ultraviolet lamp 26, and if it is thermosetting type, a heating source such as a heater can be used instead of the ultraviolet lamp 26.

[0115] In the anti-glare film of the third embodiment, since it is not necessary to disperse fine particles in the anti-glare layer 33, the light incident on the anti-glare film is scattered at a wide angle due to the refractive index difference between the matrix resin and the fine particles in the anti-glare layer, thereby effectively preventing the anti-glare film from becoming discolored.

[0116] Furthermore, the anti-glare layer of the anti-glare film according to each of the above embodiments may have an upper layer positioned on the surface opposite to the base film 2. Providing this upper layer makes it easier to adjust the external haze of the anti-glare layer and also makes it easier to protect the anti-glare film from the outside.

[0117] The thickness of the upper layer can be set as appropriate, but for example, it can be set to a value in the range of 10 nm to 2 μm. It is more desirable that the thickness of the upper layer be in the range of 50 nm to 1 μm, and even more desirable that it be in the range of 70 nm to 500 nm. Below, the glare inspection machine and glare evaluation method for inspecting and evaluating the anti-glare films of each of the above embodiments will be described in order.

[0118] (Glare inspection machine) Figure 3 is a schematic diagram of the glare inspection machine 10. The glare inspection machine 10 is a device for evaluating the glare of a display 16a in a display device 16 that has a film such as an anti-glare film 1 attached to its surface, and comprises a housing 11, an imaging device 12, a holding unit 13, a stand for the imaging device 14, a stand for the display device 15, and an image processing device 17. An example of a commercially available glare inspection machine 10 is the "Film Glare Inspection Machine" manufactured by Komatsu NTC Corporation.

[0119] The housing 11 has a darkroom for imaging the display 16a with the imaging device 12. The housing 11 houses the imaging device 12, the holding unit 13, the mounting base 14 for the imaging device, the mounting base 15 for the display device, and the display device 16 to be evaluated.

[0120] The imaging device 12 is, for example, an area camera having a lens 18 and an image sensor, and captures images displayed on the display 16a. The imaging device 12 is connected to the image processing device 17 and is held in the holding unit 13 so that the lens 18 and the display 16a face each other. The image data captured by the imaging device 12 is transmitted to the image processing device 17.

[0121] The holding portion 13 extends vertically and holds the imaging device 12 while being fixed to the mounting base 14 for the imaging device at its lower end. The holding portion 13 holds the imaging device 12 so that the relative distance between the display 16a and the lens 18 can be changed by moving the imaging device 12 vertically relative to the display device 16.

[0122] The display device 16 is placed on the upper surface of the display device stand 15 with the display 16a, which has the film attached, facing the imaging device 12. The display device stand 15 supports the display 16a with the film attached so that its surface faces the imaging device 12 and is on a horizontal plane, and moves the display device 16 relative to the imaging device 12 in a vertical direction.

[0123] In the glare inspection machine 10, the pixel size of the image displayed on the display 16a, which is captured per unit pixel (e.g., 1 pixel) of the image sensor of the imaging device 12, is adjusted by adjusting the relative distance between the imaging device 12 and the display 16a.

[0124] The image processing device 17 performs data processing on the image data captured by the imaging device 12. Specifically, the image processing device 17 calculates the standard deviation of the brightness of the display 16a from the image data captured by the imaging device 12.

[0125] The image processing apparatus 17 of this embodiment includes an input unit that receives image data captured by the imaging device 12, an image processing unit that processes the input image data, and an output unit that outputs the results processed by the image processing unit to a display device or printing device, etc.

[0126] When the image displayed on the display 16a is captured by the imaging device 12, the pixel size of the image captured per unit pixel (for example, 1 pixel) of the image sensor can be adjusted by changing the relative distance between the imaging device 12 and the display 16a, or, if the lens 18 provided by the imaging device 12 is a zoom lens, by changing the focal length of the imaging device 12.

[0127] (Method for evaluating glare) Next, a method for evaluating the glare of a display 16a using a glare inspection machine 10 will be described. In this glare evaluation method, for the convenience of evaluation, the display 16a, which has a film attached to its surface, is pre-lit and displayed with uniform illumination of a single color (green as an example).

[0128] Next, an adjustment step is performed to adjust the pixel size of the display 16a, which is fitted with a film, for each unit pixel of the image sensor of the imaging device 12. In the adjustment step, the relative distance between the imaging device 12 and the display 16a fitted with the film is adjusted according to the effective number of pixels of the image sensor of the imaging device 12, so that there are no bright lines caused by pixels in the image captured by the imaging device 12, or even if there are bright lines caused by pixels, they do not affect the evaluation of the glare of the display 16a.

[0129] Furthermore, it is desirable that the relative distance between the imaging device 12 and the display device 16 be set considering the manner in which the display device 16 is used (for example, the relative distance between the user's eye and the surface of the display 16a).

[0130] After performing the adjustment step, a setting step is performed to set a measurement area for evaluating the glare of the display 16a with the film attached. In the setting step, the measurement area is set appropriately according to, for example, the size of the display 16a.

[0131] After the adjustment step, an imaging step is performed in which the measurement area of ​​the display 16a with the film attached is imaged by the imaging device 12. At this time, as an example, at least one of the exposure time of the imaging device 12 or the brightness of all pixels of the display 16a is adjusted so that image data is obtained as a grayscale image with 8-bit gradation display and an average brightness of 170 gradations. The image data captured in the imaging step is input to the image processing device 17.

[0132] After the imaging step, the image processing device 17 performs a calculation step using the image data to determine the variation in brightness in the measurement area of ​​the display 16a with the film attached. In this calculation step, the variation in brightness is quantified as the standard deviation of the brightness distribution.

[0133] Here, the glare of the display 16a with the film attached increases as the variation in brightness of the display 16a with the film attached increases. As a result, the smaller the standard deviation of the brightness distribution, the less glare the display 16a has. Furthermore, in the adjustment step, the brightness lines of the display 16a with the film attached are adjusted to such an extent that they do not affect the evaluation of the glare of the display 16a, thereby suppressing brightness unevenness caused by the brightness lines and enabling an accurate evaluation of the glare of the display 16a. By going through each of the above steps, the standard deviation of the brightness distribution of the display 16a with the film attached to its surface can be determined, and the glare of the display 16a can be evaluated based on this value.

[0134] (Examples and Comparative Examples) The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. Examples 1 to 6 form the anti-glare layer 3 using a phase separation structure as the basic structure.

[0135] Comparative Example 1 involves forming an anti-glare layer with increased haze value using commonly used high-refractive-index beads (polystyrene beads). Comparative Example 2 involves forming an anti-glare layer with increased haze value using high-refractive-index nanoparticles (zirconia microparticles). Comparative Example 3 uses a phase-separated structure as its basic structure and forms an anti-glare layer with increased haze value using low-refractive-index nanoparticles (hollow silica gel particles). In the following descriptions of the examples and comparative examples, the refractive index mentioned refers to the refractive index after crosslinking (after curing) for materials that harden by crosslinking.

[0136] [Example 1] 12.5 parts by weight of methyl methacrylate-3,4-epoxycyclohexylmethyl methacrylate copolymer (manufactured by Daicel Ornex Co., Ltd., Cyclomer P, refractive index 1.51), 4 parts by weight of cellulose acetate propionate (acetylation degree = 2.5%, propionyl degree = 46%, polystyrene equivalent number-average molecular weight 75000; manufactured by Eastman, CAP-482-20, refractive index 1.49), and an acrylic UV-curable compound containing nanosilica (refractive index 1.46) (Momentive Performance A solution was prepared by dissolving 150 parts by weight of UVHC7800G (manufactured by Mans Materials Japan LLC), 1 part by weight of silicone acrylate (manufactured by Daicel Ornex Co., Ltd., EB1360, refractive index 1.52), 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 184), and 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 907) in a mixed solvent of 81 parts by weight of methyl ethyl ketone, 24 parts by weight of 1-butanol, and 13 parts by weight of 1-methoxy-2-propanol.

[0137] This solution was cast onto a polyethylene terephthalate film (substrate film 2) using a wire bar (#20), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick. The coating layer was then UV-cured by irradiating it with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds. This formed an anti-glare layer 3, and the anti-glare film of Example 1 was obtained.

[0138] [Example 2] 15.0 parts by weight of methyl methacrylate-3,4-epoxycyclohexylmethyl methacrylate copolymer (manufactured by Daicel Ornex Co., Ltd., Cyclomer P, refractive index 1.51), 3 parts by weight of cellulose acetate propionate (acetylation degree = 2.5%, propionyl degree = 46%, polystyrene equivalent number-average molecular weight 75000; manufactured by Eastman, Inc., CAP-482-20, refractive index 1.49), and an acrylic ultraviolet (UV) curable compound containing nanosilica (refractive index 1.46). A solution was prepared by dissolving 150 parts by weight of UVHC7800G (manufactured by Momentive Performance Materials Japan LLC), 1 part by weight of silicone acrylate (manufactured by Daicel Ornex Co., Ltd., EB1360, refractive index 1.52), 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 184), and 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 907) in a mixed solvent of 101 parts by weight of methyl ethyl ketone and 24 parts by weight of 1-butanol.

[0139] This solution was cast onto a polyethylene terephthalate film (substrate film 2) using a wire bar (#20), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick. The coating layer was then UV-cured by irradiating it with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds. This formed an anti-glare layer 3, and the anti-glare film of Example 2 was obtained.

[0140] [Example 3] 12.5 parts by weight of methyl methacrylate-3,4-epoxycyclohexylmethyl methacrylate copolymer (manufactured by Daicel Ornex Co., Ltd., Cyclomer P, refractive index 1.51), 4 parts by weight of cellulose acetate propionate (degree of acetylation = 2.5%, degree of propionyl = 46%, number-average molecular weight in polystyrene equivalent 75000; manufactured by Eastman, CAP-482-20, refractive index 1.49), and an acrylic UV-curable compound containing nanosilica (refractive index 1.46). A solution was prepared by dissolving 209.3 parts by weight of volatile catalyst (HP-1004, manufactured by Volcanic Catalysts Co., Ltd.), 1 part by weight of silicone acrylate (EB1360, refractive index 1.52, manufactured by Daicel Ornex Co., Ltd.), 1 part by weight of photoinitiator (Irgacure 184, manufactured by BASF Japan Ltd.), and 1 part by weight of photoinitiator (Irgacure 907, manufactured by BASF Japan Ltd.) in a mixed solvent of 31 parts by weight of methyl ethyl ketone, 25 parts by weight of 1-butanol, and 12 parts by weight of 1-methoxy-2-propanol.

[0141] This solution was cast onto a polyethylene terephthalate film (substrate film 2) using a wire bar (#20), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick. The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds to UV-cur the coating layer. This formed an anti-glare layer 3, and the anti-glare film of Example 3 was obtained.

[0142] [Example 4] A solution was prepared by dissolving 34.2 parts by weight of acrylic polymer (manufactured by Taisei Fine Chemical Co., Ltd., 8KX-078), 20 parts by weight of urethane-modified copolymer polyester resin (manufactured by Toyobo Co., Ltd., UR-3200), 131.7 parts by weight of nanosilica (refractive index 1.46)-containing acrylic UV-curable compound (manufactured by Momentive Performance Materials Japan LLC, UVHC7800G), 1 part by weight of silicone acrylate (manufactured by Daicel Ornex Co., Ltd., EB1360, refractive index 1.52), 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 184), and 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 907) in 213 parts by weight of methyl ethyl ketone.

[0143] This solution was cast onto a polyethylene terephthalate film (substrate film 2) using a wire bar (#16), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick. The coating layer was then UV-cured by irradiating it with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds. This formed the anti-glare layer 3, and the anti-glare film of Example 4 was obtained.

[0144] [Example 5] A solution was prepared by dissolving 34.2 parts by weight of acrylic polymer (manufactured by Taisei Fine Chemical Co., Ltd., 8KX-078), 20 parts by weight of urethane-modified copolymer polyester resin (manufactured by Toyobo Co., Ltd., UR-3200), 131.7 parts by weight of nanosilica (refractive index 1.46)-containing acrylic UV-curable compound (manufactured by Momentive Performance Materials Japan LLC, UVHC7800G), 5 parts by weight of silicone acrylate (manufactured by Daicel Ornex Co., Ltd., EB1360, refractive index 1.52), 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 184), and 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 907) in 213 parts by weight of methyl ethyl ketone.

[0145] This solution was cast onto a polyethylene terephthalate film (substrate film 2) using a wire bar (#16), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick. The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds to UV-cur the coating layer. This formed the anti-glare layer 3, and the anti-glare film of Example 5 was obtained.

[0146] [Example 6] A solution was prepared by dissolving 47.5 parts by weight of methyl methacrylate-3,4-epoxycyclohexylmethyl methacrylate copolymer (manufactured by Daicel Ornex Co., Ltd., Cyclomer P, refractive index 1.51), 1.5 parts by weight of cellulose acetate propionate (degree of acetylation = 2.5%, degree of propionyl = 46%, number-average molecular weight in polystyrene equivalent 75000; manufactured by Eastman, CAP-482-20, refractive index 1.49), 79.5 parts by weight of urethane acrylate (manufactured by Shin Nakamura Chemical Industry Co., Ltd., UA-53H), 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 184), and 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 907) in a mixed solvent of 175 parts by weight of methyl ethyl ketone, 28 parts by weight of 1-butanol, and 2 parts by weight of 1-methoxy-2-propanol.

[0147] This solution was cast onto a polyethylene terephthalate film (substrate film 2) using a wire bar (#14), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 6 μm thick. The coating layer was then UV-cured by irradiating it with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds. This formed the anti-glare layer 3, and the anti-glare film of Example 6 was obtained.

[0148] [Comparative Example 1] A solution was prepared by dissolving 39 parts by weight of urethane acrylate (manufactured by Tokushiki Co., Ltd., AU-230, refractive index 1.52), 15.7 parts by weight of silicone-based hard coat material (manufactured by Tokushiki Co., Ltd., AS-201S), 0.3 parts by weight of PMMA beads (manufactured by Sekisui Chemical Co., Ltd., SSX-115, refractive index 1.50), and 6.1 parts by weight of cross-linked styrene beads (manufactured by Soken Chemical Co., Ltd., SX-130H, refractive index 1.59) in 38 parts by weight of methyl ethyl ketone.

[0149] This solution was cast onto a polyethylene terephthalate film (base film) using a wire bar (#14), and then left in a 100°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 6 μm thick. The coating layer was then UV-cured by irradiating it with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds. This formed an anti-glare layer, yielding the anti-glare film of Comparative Example 1.

[0150] [Comparative Example 2] A solution was prepared by dissolving 50 parts by weight of dipentaerythritol hexaacrylate (manufactured by Daicel Ornex Co., Ltd., DPHA, refractive index 1.52), 50 parts by weight of pentaerythritol tetraacrylate (manufactured by Daicel Ornex Co., Ltd., PETRA, refractive index 1.52), 100 parts by weight of zirconia microparticle (refractive index approximately 2.0) dispersion (manufactured by Toyo Ink Co., Ltd., RioDuras TYZ), 2 parts by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 184), and 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 907) in a mixed solvent of 116 parts by weight of methyl ethyl ketone, 19 parts by weight of 1-butanol, and 58 parts by weight of 1-methoxy-2-propanol.

[0151] This solution was cast onto a polyethylene terephthalate film (base film) using a wire bar (#14), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 6 μm thick. The coating layer was then UV-cured by irradiating it with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds. This formed an anti-glare layer, yielding the anti-glare film of Comparative Example 2.

[0152] [Comparative Example 3] 12.5 parts by weight of methyl methacrylate-3,4-epoxycyclohexylmethyl methacrylate copolymer (manufactured by Daicel Ornex Co., Ltd., Cyclomer P, refractive index 1.51), 4 parts by weight of cellulose acetate propionate (degree of acetylation = 2.5%, degree of propionyl = 46%, number-average molecular weight in polystyrene equivalent 75000; manufactured by Eastman, CAP-482-20, refractive index 1.49), 125 parts by weight of dipentaerythritol hexaacrylate (manufactured by Daicel Ornex Co., Ltd., DPHA) A solution was prepared by dissolving 1 part by weight of silicone acrylate (manufactured by Daicel Ornex Co., Ltd., EB1360, refractive index 1.52), 75 parts by weight of hollow silica gel (manufactured by JGC Catalysts & Chemicals Co., Ltd., Thru-Ria, refractive index 1.25), 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 184), and 1 part by weight of photoinitiator (manufactured by BASF Japan Ltd., Irgacure 907) in a mixed solvent of 56 parts by weight of methyl ethyl ketone, 11 parts by weight of 1-butanol, and 10 parts by weight of 1-methoxy-2-propanol.

[0153] This solution was cast onto a polyethylene terephthalate film (base film) using a wire bar (#20), and then left in an 80°C oven for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick. The coating layer was then UV-cured by irradiating it with ultraviolet light from a high-pressure mercury lamp for approximately 5 seconds. This formed an anti-glare layer, yielding the anti-glare film of Comparative Example 3.

[0154] Next, the following items were measured and evaluated for each anti-glare film in Examples 1-6 and Comparative Examples 1-3: haze and total light transmittance, 60-degree gloss, surface structure, and transmitted hue (a * ,b * The adhesive layer was omitted during the measurement of ( ).

[0155] [Haze and total light transmittance] The haze was measured using a haze meter (NDH-5000W, manufactured by Nippon Denshoku Co., Ltd.) in accordance with JIS K7136. Haze was measured with the surface having the uneven structure of the anti-glare layer facing the light receiver. Internal haze was measured by laminating a smooth transparent film to the surface with the uneven structure of the anti-glare layer via a transparent adhesive layer.

[0156] [60 degree gloss] A gross meter (Horiba, Ltd., IG-320) was used to measure the temperature at a 60° angle, in accordance with JIS K7105.

[0157] [Surface structure] Using a contact-type surface roughness meter (Surfcom 570A, manufactured by Tokyo Seimitsu Co., Ltd.), the centerline average surface roughness (Ra) and average peak-to-trough spacing (Sm) were measured in accordance with JIS B0601, under the conditions of a scanning range of 3 mm and 2 scans.

[0158] [Transparent hue (a * ,b * )] Measurements were taken using a spectrophotometer (Hitachi High-Tech Science Co., Ltd., U-3010) in accordance with JIS Z8781.

[0159] [Standard deviation of display brightness distribution (glare value)] A smartphone (Samsung Galaxy S4) was used as the display device 16, and the anti-glare films of each sample were attached to the surface of its display 16a using an adhesive layer (optical glue). Using a Komatsu NTC film glare inspection machine 10, the standard deviation of the brightness distribution of the display 16a (glare σ: glare value) was measured through the anti-glare film of each sample. For this measurement, at least one of the exposure time of the imaging device 12 or the brightness of all pixels of the display 16a was adjusted so that image data was obtained as a grayscale image with 8-bit gradation display and an average brightness of 170 gradations. The results of each measurement are shown in Table 1.

[0160] [Table 1]

[0161] As shown in Table 1, the anti-glare layer 3 of Examples 1 to 6 is set to a haze value in the range of 67.8% to 91.49%, and the internal haze value is set to a value in the range of 3.3% to 13.0%, which is smaller than the internal haze value of Comparative Examples 1 to 3. Furthermore, the 60-degree gloss (%) value of the anti-glare layer 3 of Examples 1 to 6 is sufficiently suppressed compared to the 60-degree gloss (%) value of the anti-glare layer of Comparative Examples 1 to 3. In addition, the anti-glare films of Examples 1 to 6 and Comparative Examples 1 to 3 all suppress the glare value (glare σ) of the display 16a to a value in the range of 0 to 10.

[0162] As shown in Table 1, Examples 1 to 6 suppress the glare value of the display 16a to the same extent as Comparative Examples 1 to 3, while exhibiting better anti-glare properties compared to Comparative Examples 1 to 3, and b * It was found that suppressing the value effectively prevents the anti-glare film from becoming discolored.

[0163] The reason for this is that, in Examples 1 to 6, the uneven surface structure of the anti-glare layer 3 is basically formed by a phase separation structure, and the refractive index difference between the resins combined to form the phase separation structure in the anti-glare layer 3 is suppressed (here, each refractive index value is set to be equal). Therefore, even though the anti-glare layer 3 has a relatively high haze value, it is possible that the scattering of transmitted light at a wide angle within it is prevented.

[0164] Furthermore, although the anti-glare layer 3 in Examples 1 to 5 contains fine particles (nanosilica particles), the refractive index values ​​of the resin forming the phase separation structure and the fine particles are almost equal (0.07 or less), which is thought to prevent the scattering of transmitted light to wide angles and thus prevent discoloration of the anti-glare film 1.

[0165] Furthermore, based on the characteristic trends shown in Examples 1 to 6 and other studies conducted by the present inventors, it is believed that the same effects as in Examples 1 to 6 can be achieved even when the haze value is set to a value in the range of 60% or more and less than 67.8%, or greater than 91.49% and less than or equal to 95%, the internal haze value is set to a value in the range of 0.5% or more and less than 3.3%, or greater than 13.0% and less than or equal to 15.0%, and the glare value is set to a value in the range of 0 or more and less than 4.34, or greater than or equal to 9.01 and less than or equal to 10.

[0166] Comparative Examples 1-3 have relatively larger internal haze values ​​compared to Examples 1-6, and also b * The values ​​were also found to be large. In Comparative Example 1, it is thought that the difference in refractive index between the matrix resin and the beads added in relatively large amounts relative to the matrix resin in the anti-glare layer caused a large amount of wide-angle scattering of low-wavelength light (blue light), which is prone to scattering, among the transmitted light, resulting in the anti-glare film being colored with a yellowish tint.

[0167] In Comparative Example 2, the internal haze value was increased by adding fine particles (nanoparticles) with a relatively high refractive index to the anti-glare layer, while in Comparative Example 3, the internal haze value was increased by adding fine particles (nanoparticles) with a lower refractive index compared to the anti-glare layer having a phase separation structure.

[0168] However, in Comparative Examples 2 and 3, the refractive index difference between the matrix resin and the fine particles was relatively large, and, similar to Comparative Example 1, a lot of low-transmittance light was scattered at a wide angle, which is thought to have caused the anti-glare film to take on a yellowish tint.

[0169] Furthermore, from the results of Examples 1 to 5 and Comparative Example 3, it was found that even when an anti-glare layer is formed using a phase-separated structure as the basic structure, if the refractive index difference between the matrix resin and fine particles in the anti-glare layer is relatively large, scattering of transmitted light to a wide angle may occur, which may cause the anti-glare film to become discolored.

[0170] Therefore, when adding fine particles to the anti-glare layer, it is desirable to suppress the refractive index difference between the resin or matrix resin that forms the phase separation structure and the fine particles in order to prevent discoloration of the anti-glare film.

[0171] The present invention is not limited to the embodiments described above, and its configuration or methods may be changed, added, or deleted without departing from the spirit of the invention. For example, the fine particles of the second embodiment may be dispersed in the anti-glare layer of the first or third embodiment. [Explanation of Symbols]

[0172] 1. Anti-glare film 3,33 Anti-glare layer 16a display

Claims

1. An anti-glare layer is provided, wherein, when attached to the surface of an organic EL display having an internal haze value in the range of 3.3% to 8.0%, a center line mean roughness Ra in the range of 0.32 μm to 0.88 μm, and a pixel density of 441 ppi, the standard deviation of the brightness distribution of the display is 0 to 10 when adjusted so that image data is obtained as a grayscale image with 8-bit grayscale display and an average brightness of 170 levels, and the display is equipped with an anti-glare layer. The anti-glare layer comprises a matrix resin and a plurality of fine particles dispersed in the matrix resin, wherein the plurality of fine particles have an average particle size in the range of 1.0 μm to 3.0 μm, are composed of inorganic materials, and are transparent, and the inclusion of fine particles other than the plurality of fine particles in the anti-glare layer is excluded. The refractive index difference between the matrix resin and the plurality of fine particles is in the range of 0.07 to 0.

2. An anti-glare film in which the ratio G2 / G1 of the weight G1 of the matrix resin to the total weight G2 of the plurality of fine particles is in the range of 0.1 to 0.

2.

2. The anti-glare film according to claim 1, wherein the anti-glare layer comprises a plurality of resin components and has a co-continuous phase structure formed by the phase separation of the plurality of resin components.

3. The anti-glare film according to claim 1 or 2, wherein the ratio G2 / G1 is a value in the range of 0.12 or more and 0.20 or less.

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