Anti-glare film

Abstract

The present invention provides an antiglare film that can suppress glare on a display while having good antiglare properties, and that also has a high degree of freedom in designing for high transmitted image clarity, by quantitatively evaluating and designing glare on a display. [Solution] The antiglare film has an antiglare layer with a haze value in the range of 50% to 99%, and when attached to the surface of a display, the standard deviation of the display's luminance distribution is in the range of 0 to 6, and the transmitted image clarity at an optical comb width of 0.5 mm is in the range of 0 to 60%.

Description

[Technical Field]

[0001] The present invention relates to an antiglare film that prevents external light from being reflected on the surface of a display. [Background technology]

[0002] An antiglare film is, for example, a film having an antiglare layer with an uneven surface formed by roughening, and is attached to the surface of a display to scatter external light and prevent it from being reflected on the surface of the display.

[0003] Methods for forming irregularities on the surface of an antiglare layer include, for example, a method of dispersing fine particles (filler) in the antiglare layer as disclosed in Patent Document 1, a method of utilizing a phase separation structure formed by spinodal decomposition from the liquid phase of multiple polymers as disclosed in Patent Document 2, and a method of transfer molding an irregular shape using a mold as disclosed in Patent Document 3. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-109702 [Patent Document 2] Patent No. 3559505 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-102356 Summary of the Invention [Problem to be solved by the invention]

[0005] When an anti-glare film is attached to the surface of a display, it prevents external light from being reflected on the display surface. However, the light from the display may be affected by the anti-glare film, which may reduce the display performance of the display through the anti-glare film. For this reason, it is desirable for the anti-glare film to have a high degree of freedom in designing the clarity of transmitted images.

[0006] Furthermore, when an anti-glare film is attached to the surface of a display or the like having high-definition pixels, the light from the display that passes through the anti-glare film may be refracted by the unevenness of the surface of the anti-glare layer, or the unevenness of the surface of the anti-glare layer may have a lens effect that makes the pixels of the display appear enlarged, resulting in glare on the display and making it difficult to see the image.

[0007] One possible method for suppressing glare on displays is to reduce the surface irregularities of the anti-glare layer, but this may result in a decrease in the anti-glare properties of the anti-glare film. Furthermore, glare on displays can be difficult to quantitatively evaluate, making it difficult to develop an anti-glare film that can effectively suppress glare on displays according to objective indicators.

[0008] Therefore, the present invention aims to provide an antiglare film that can suppress glare on a display while maintaining good antiglare properties, and that also has design freedom for high transmitted image clarity, by quantitatively evaluating and designing glare on the display. [Means for solving the problem]

[0009] In order to solve the above problem, one aspect of the present invention comprises an antiglare layer having a haze value in the range of 50% to 99%, wherein the standard deviation of the luminance distribution of the display when attached to the surface of the display is in the range of 0 to 6, and the transmitted image clarity at an optical comb width of 0.5 mm is in the range of 0 to 60%.

[0010] Here, the standard deviation value of the display's luminance distribution indicates the degree of variation in the number of bright spots on the display and serves as an objective index for quantitatively evaluating display glare. Therefore, in the above configuration, by configuring the anti-glare layer with the standard deviation set to a value in the range of 0 to 6, it is possible to quantitatively evaluate display glare and design an anti-glare film. Therefore, compared to, for example, cases where glare is subjectively evaluated visually by an examiner, it is possible to consistently obtain an anti-glare film that can effectively suppress display glare.

[0011] Furthermore, by setting the standard deviation to a predetermined value and the haze value of the antiglare layer to a value in the range of 50% to 99%, it is possible to obtain good antiglare properties while suppressing glare on the display. Furthermore, by setting the transmitted image clarity of the antiglare film at an optical comb width of 0.5 mm to a value in the range of 0% to 60%, it is possible to ensure wide design freedom for the transmitted image clarity of the antiglare film.

[0012] The antiglare layer may contain a plurality of resin components and have a bicontinuous phase structure formed by phase separation of the plurality of resin components. By utilizing such a bicontinuous phase structure, it is possible to easily obtain good antiglare properties while suppressing glare on a display.

[0013] The antiglare layer may contain an acrylic copolymer, cellulose acetate propionate, and at least one of a nanosilica-containing acrylic ultraviolet-curable compound and a urethane acrylate, which facilitates the production of an antiglare film that has antiglare properties while suppressing glare on a display.

[0014] The antiglare layer may include a matrix resin and a plurality of fine particles dispersed in the matrix resin, and the difference in refractive index between the fine particles and the matrix resin may be within a range of 0 or more and 0.07 or less.

[0015] This allows the antiglare layer to be constructed using a matrix resin and a plurality of fine particles, making it easier to produce an antiglare film that has antiglare properties while suppressing glare on a display.

[0016] The ratio G2 / G1 of the weight G1 of the matrix resin in 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 to 0.20, thereby enabling the antiglare film to be successfully produced, which has an antiglare layer with a structure in which the plurality of fine particles are dispersed in the matrix resin. [Effects of the Invention]

[0017] According to the present invention, by quantitatively evaluating and designing glare on a display, it is possible to provide an antiglare film that can suppress glare on a display while maintaining good antiglare properties, and that has a high degree of freedom in designing for high clarity of transmitted images. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view showing the configuration of an antiglare film according to a first embodiment. [Figure 2] 5A to 5C are diagrams illustrating a method for manufacturing an antiglare film according to a second embodiment. [Figure 3] FIG. 1 is a schematic diagram of a glare inspection machine. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

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

[0021] The base film 2 is disposed between the display 16a and the antiglare layer 3 and supports the antiglare layer 3. The adhesive layer 4 is disposed between the display 16a and the base film 2 and fixes the antiglare 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 is unlikely to affect the optical properties of the antiglare film 1.

[0022] The antiglare layer 3 is formed on at least one surface of the base film 2. The antiglare layer 3 imparts antiglare properties to the antiglare film 1 and scatters and reflects external light to prevent the external light from being reflected on the surface of the display 16a. The antiglare layer 3 also functions as a hard coat (HC) layer that protects the surface of the display 16a. The antiglare layer 3 contains, for example, multiple phase-separable resin components.

[0023] The antiglare film 1 has a standard deviation of the luminance distribution of the display 16a set to a value in the range of 0 to 6 when attached to the surface of the display 16a, and a transmitted image clarity at an optical comb width of 0.5 mm set to a value in the range of 0 to 60%. The antiglare layer 3 has a haze value set to a value in the range of 50 to 99%.

[0024] The haze value shown in this embodiment is a value measured by a method conforming to JIS K7136.

[0025] The value of the standard deviation can be set appropriately within the above range, but is more preferably a value in the range of 0 to 5.5, and even more preferably a value in the range of 0 to 5.0. The value of the transmitted image clarity (image clarity) for an optical comb width of 0.5 mm can also be set appropriately within the above range, but is more preferably a value in the range of 0 to 55%, and even more preferably a value in the range of 0 to 50%.

[0026] The haze value of the antiglare layer 3 can be set appropriately within the above range, but is more preferably in the range of 50% to 90%, and even more preferably in the range of 50% to 85%.

[0027] In this embodiment, the standard deviation value of the luminance distribution of display 16a indicates the degree of variation in bright spots on display 16a and serves as an objective index for quantitatively evaluating the glare of display 16a. Therefore, by configuring antiglare film 1 so that the standard deviation is set to a value in the range of 0 to 6, the glare of display 16a can be quantitatively evaluated and antiglare film 1 can be designed.

[0028] Therefore, compared to when glare on the display 16a is subjectively evaluated visually by a tester, an antiglare film 1 that can effectively suppress glare on the display 16a can be obtained stably.

[0029] Furthermore, by setting the standard deviation of the antiglare film 1 to a predetermined value and setting the haze value of the antiglare layer 3 to a value in the range of 50% to 99%, it is possible to obtain good antiglare properties while suppressing glare on the display 16a. Furthermore, by setting the transmitted image clarity of the antiglare film 1 at an optical comb width of 0.5 mm to a value in the range of 0% to 60%, it is possible to ensure wide design freedom for the transmitted image clarity of the antiglare film 1.

[0030] The antiglare layer 3 of this embodiment contains multiple resin components and has a bicontinuous phase structure formed by phase separation of these multiple resin components. By utilizing such a bicontinuous phase structure, the antiglare film 1 can easily achieve good antiglare properties while suppressing glare on the display 16a.

[0031] The antiglare layer 3 of this embodiment contains an acrylic copolymer, cellulose acetate propionate, and at least one of a nanosilica-containing acrylic ultraviolet-curable compound and a urethane acrylate (both in this example). This facilitates the production of an antiglare film 1 that has antiglare properties while suppressing glare on the display 16a. Specific examples of the substrate film 2 and the antiglare layer 3 are described below.

[0032] Examples of materials for the substrate film 2 include glass, ceramics, and resins. The resin may be the same as the material for the antiglare layer 3. Preferred materials for the substrate film 2 include transparent polymers, such as 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), polysulfone resins (polysulfone, polyethersulfone (PES), etc.), polyetherketone resins (polyetherketone (PEK), polyethersulfone (PES), etc.), and the like. Examples of suitable resins include polyether ether ketone (PEEK), 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).

[0033] The base film 2 may be uniaxially or biaxially stretched, but is preferably optically isotropic and has a low refractive index. An example of the optically isotropic base film 2 is an unstretched film.

[0034] The thickness dimension of the base film 2 can be set as appropriate, but is preferably in the range of 5 μm or more and 2000 μm or less, more preferably in the range of 15 μm or more and 1000 μm or less, and even more preferably in the range of 20 μm or more and 500 μm or less.

[0035] [Structure of anti-glare layer] The antiglare layer 3 of the first embodiment has a phase-separated structure of a plurality of resin components. As an example, the antiglare layer 3 has a plurality of elongated (string-like or linear) convex portions formed on the surface due to the phase-separated structure of a plurality of resin components. The elongated convex portions are branched and form a dense co-continuous phase structure.

[0036] The antiglare layer 3 exhibits antiglare properties through a plurality of elongated convex portions and concave portions located between adjacent elongated convex portions. The antiglare film 1 has an excellent balance between haze value and transmitted image clarity (image clarity) due to the presence of such an antiglare layer 3. The surface of the antiglare layer 3 has a mesh-like structure, in other words, a structure of a plurality of continuous or partially missing irregular loops, due to the elongated convex portions being formed in a roughly mesh-like pattern.

[0037] The formation of the above-described structure on the surface of the antiglare layer 3 prevents the formation of lens-shaped (sea-island) convex portions. This prevents light from the display 16a passing through the antiglare layer 3 from being refracted by the unevenness of the surface of the antiglare layer 3, and prevents the pixels of the display 16a from appearing enlarged due to the lens effect of the unevenness of the surface of the antiglare layer 3, thereby suppressing glare on the display 16a. As a result, even when the antiglare film 1 is attached to a display 16a with high-definition pixels, glare on the display 16a can be suppressed to a high degree while maintaining antiglare properties, and blurring of characters and images and changes in color tone can also be suppressed.

[0038] The plurality of elongated convex portions may be independent of each other or may be connected to each other. As will be described later, the phase-separated structure of the antiglare layer 3 is formed by spinodal decomposition (wet spinodal decomposition) from a liquid phase using a solution that is the raw material of the antiglare layer 3. For details of the antiglare layer 3, see, for example, the description in Japanese Patent Application No. 2012-231496.

[0039] [Anti-glare layer material] The multiple resin components contained in the antiglare layer 3 may be any components that are phase-separable, but from the viewpoint of obtaining an antiglare layer 3 on which elongated convex portions are formed and which has high scratch resistance, it is preferable that the antiglare layer 3 contain a polymer and a curable resin.

[0040] Examples of polymers contained in the antiglare layer 3 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.), rubber 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.

[0041] 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.

[0042] The functional group may be a condensable group or a reactive group (e.g., a hydroxyl group, an acid anhydride group, a carboxyl group, an amino group or an imino group, an epoxy group, a glycidyl group, an isocyanate group, etc.), a polymerizable group (e.g., a C group such as vinyl, propenyl, isopropenyl, butenyl, or allyl group), or a C group such as a hydroxyl group, an acid anhydride group, a carboxyl group, an amino group, an imino group, an epoxy group, a glycidyl group, an isocyanate group, etc.). 2-6 C such as alkenyl group, ethynyl, propynyl, butynyl group 2-6 C such as alkynyl group, vinylidene group 2-6 Examples include alkenylidene groups, and groups having such polymerizable groups (e.g., (meth)acryloyl groups, etc.) Among these functional groups, polymerizable groups are preferred.

[0043] The antiglare layer 3 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.

[0044] 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.

[0045] 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 (polystyrene, styrene-acrylonitrile copolymer, etc.), a (meth)acrylic resin, 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.

[0046] The multiple 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.

[0047] Here, the phase-separated structure of the antiglare layer 3 is fixed by curing a precursor of a curable resin contained in the multiple resin components with active energy rays (ultraviolet rays, electron beams, etc.), heat, etc. during the production of the antiglare layer 3. Furthermore, such a curable resin imparts scratch resistance and durability to the antiglare layer 3.

[0048] From the viewpoint of obtaining scratch resistance in the antiglare layer 3, it is preferable 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 that forms the phase separation 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 appropriately.

[0049] Examples of curable resin precursors include curable compounds that have functional groups that react with active energy rays (ultraviolet rays, electron beams, etc.) or heat, and that are cured or crosslinked by these functional groups to form a resin (particularly a cured resin or a crosslinked resin).

[0050] 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).

[0051] A preferred example of the curable resin precursor is a photocurable compound that cures in a short time with ultraviolet light, electron beams, or the like. Of these, ultraviolet curable compounds are particularly practical. In order to improve resistance such as scratch resistance, the photocurable compound preferably has two or more (preferably 2 to 15, more preferably about 4 to 10) polymerizable unsaturated bonds in the molecule. Specifically, the photocurable compound is preferably 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.

[0052] 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.

[0053] 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.

[0054] In the manufacturing process of the antiglare layer 3, at least two of the polymers and curable resin precursors contained in the solution serving as raw materials for the antiglare layer 3 are used in a combination that causes phase separation at or 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 types of curable resin precursors are immiscible with each other and cause phase separation. Among these combinations, typically, (a) a combination of multiple types of polymers and (b) a combination of a polymer and a curable resin precursor are used, and in particular, (a) a combination of multiple types of polymers is preferred.

[0055] Typically, the polymer and the cured or crosslinked resin produced by curing the curable resin precursor have different refractive indices. Also, the refractive indices of the multiple polymers (first and second polymers) typically differ from each other. The difference in refractive index between the polymer and the cured or crosslinked resin, and the difference in refractive index between the multiple polymers (first and second polymers), are preferably within a range of 0 to 0.04, more preferably 0 to 0.02.

[0056] The antiglare layer 3 may contain a plurality of fine particles (fillers) dispersed in a matrix resin. The fine particles may be either organic fine particles or inorganic fine particles, and the plurality of fine particles may contain a plurality of types of fine particles.

[0057] Examples of organic fine particles include crosslinked acrylic particles and crosslinked styrene particles. Examples of inorganic fine particles include silica particles and alumina particles. The refractive index difference between the fine particles and the matrix resin contained in the antiglare layer 3 can be set to a value in the range of 0 to 0.20, for example. This refractive index difference is more preferably a value in the range of 0 to 0.15, and even more preferably a value in the range of 0 to 0.07.

[0058] The average particle size of the fine particles is not particularly limited and can be set to a value in the range of 0.5 μm to 5.0 μm, more preferably 0.5 μm to 3.0 μm, and even more preferably 0.5 μm to 2.0 μm.

[0059] The average particle size referred to here is the 50% volume average particle size measured by the Coulter Counter method (the same applies to the average particle size mentioned below). The fine particles may be solid or hollow. It should be noted that if the average particle size of the fine particles is too small, it becomes difficult to obtain anti-glare properties, and if it is too large, there is a risk of increased glare on the display.

[0060] The thickness of the antiglare layer 3 can be set as appropriate, but is preferably in the range of 0.3 μm to 20 μm, more preferably 1 μm to 15 μm, and even more preferably 1 μm to 10 μm. Typically, it can be set to a value in the range of 2 μm to 10 μm (particularly, a value in the range of 3 μm to 7 μm).

[0061] It is also possible to construct an antiglare film without the base film 2. In this case, the thickness of the antiglare layer 3 is preferably, for example, in the range of 1 μm to 100 μm, and more preferably in the range of 3 μm to 50 μm.

[0062] The antiglare layer 3 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 adjusters, thickeners, leveling agents, and antifoaming agents, within limits that do not impair the optical properties.

[0063] As an example, the manufacturing method of the antiglare film 1 in the first embodiment includes a preparation step of preparing a solution (hereinafter simply referred to as the solution) that serves as the raw material for the antiglare layer 3, a formation step of applying the solution prepared in the preparation step to the surface of a predetermined support (in this embodiment, the substrate 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 the curable resin precursor after the formation step.

[0064] [Preparation process] In the preparation step, a solution containing a solvent, a resin composition for constituting the antiglare layer 3, and predetermined fine particles 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 3. 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, reaction initiator, and other additives).

[0065] 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.

[0066] 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.

[0067] 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 and coatability of the solution are not impaired.

[0068] The haze value of the antiglare layer 3, the transmitted image clarity of the antiglare film 1, and the standard deviation of the luminance distribution (glare value) of a display 16a having the antiglare film 1 attached to its surface 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. Therefore, an antiglare film having the desired physical properties can be obtained by forming an antiglare layer under various conditions and measuring and understanding the physical properties of the obtained antiglare layer in advance.

[0069] [Formation process] 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 2). Examples of the solution casting or application method 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.

[0070] The solvent is removed by evaporation 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 from the liquid phase of multiple resin components due to spinodal decomposition, forming a phase-separated structure with a relatively regular interphase distance (pitch or mesh diameter). The co-continuous phase structure of elongated convex portions can be formed by setting drying conditions and formulations that ensure a certain degree of melt fluidity of the resin components after solvent evaporation.

[0071] The solvent is preferably evaporated by heat drying, as this facilitates the formation of elongated convex portions on the surface of the antiglare layer 3. Note that if the drying temperature is too low or the drying time is too short, the amount of heat imparted to the resin component will be insufficient, reducing the melt fluidity of the resin component and making it difficult to form elongated convex portions.

[0072] On the other hand, if the drying temperature is too high or the drying time is too long, the long and thin convex portions once formed may flow and lose their height, but the structure of the long and thin convex portions will be maintained. Therefore, the drying temperature and drying time can be used as a means of adjusting the antiglare properties and slip properties of the antiglare layer 3 by changing the height of the long and thin convex portions. Furthermore, in the formation process, a bicontinuous phase structure in which phase-separated structures are connected can be formed by increasing the evaporation temperature of the solvent or using a resin component with low viscosity.

[0073] As phase separation from the liquid phase of multiple resin components by spinodal decomposition progresses, a co-continuous phase structure is formed and coarsens. As the continuous phase becomes discontinuous, a droplet phase structure (an island-sea structure of independent phases, such as spherical, true spherical, discoidal, or ellipsoidal) is formed. 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.

[0074] [Curing process] 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 3. 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.

[0075] 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), etc. can be used as the light source.

[0076] When forming the adhesive layer 4, a solution containing an adhesive component is prepared, and then the solution is applied to the other side of the base film 2 by a conventional method, for example, the casting method or coating method described above in the formation process, and dried to form the adhesive layer 4.

[0077] The antiglare film 1 of the first embodiment is produced through the above steps. When a peelable support is used as the support, an antiglare film composed only of the antiglare layer 3 can be obtained by peeling the antiglare 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 antiglare film 1 having a laminated structure of the support (base film 2) and the antiglare layer 3 can be obtained.

[0078] One possible method for suppressing glare on the display 16a is to reduce the surface irregularities of the antiglare layer, but this could result in a decrease in the antiglare properties of the antiglare film. However, by not only reducing the irregularities of the antiglare layer but also increasing the slope of the irregularities of the antiglare layer to make the irregularities steeper and by increasing the number of irregularities, it is possible to improve the antiglare properties while suppressing glare on the display.

[0079] Although such irregularities can be formed in the anti-glare layer by the spinodal decomposition described above in the first embodiment, such irregularities can also be formed in the anti-glare layer by other methods. For example, even when multiple fine particles are used to form the irregularities on the surface of the anti-glare layer, as in the second embodiment, by selecting materials that strengthen 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 caused, and a distribution structure of irregularities with a steep and high number density can be formed in the anti-glare layer. Therefore, the anti-glare layers of the other embodiments will be described below, focusing on the differences from the first embodiment.

[0080] (Second embodiment) The antiglare layer of the antiglare film according to the second embodiment includes a matrix resin and a plurality of microparticles dispersed in the matrix resin. The microparticles are formed in a spherical shape, but are not limited thereto and may be formed in a substantially spherical or ellipsoidal shape. The microparticles are formed as solid particles, but may also be formed as hollow particles. When the microparticles are formed as hollow particles, the hollow portions of the microparticles may be filled with air or other gases. The antiglare layer may contain each microparticle dispersed as a primary particle, or may contain a plurality of secondary particles formed by aggregation of a plurality of microparticles.

[0081] The difference in refractive index between the matrix resin and the fine particles is set to a value in the range of 0 to 0.20, more preferably in the range of 0 to 0.15, and even more preferably in the range of 0 to 0.07.

[0082] The average particle size of the fine particles is set to a value in the range of 0.5 μm to 5.0 μm, more preferably in the range of 0.5 μm to 3.0 μm, and even more preferably in the range of 0.5 μm to 2.0 μm.

[0083] Furthermore, it is desirable that the variation in particle size of the microparticles is small. For example, in the particle size distribution of the microparticles contained in the antiglare layer, it is desirable that the average particle size of 50% by weight or more of the microparticles contained in the antiglare layer has a variation of 1.0 μm or less.

[0084] In this way, the fine particles having a relatively uniform particle size and an average particle size set within the above range form uniform and moderate irregularities on the surface of the anti-glare layer, thereby suppressing glare on the display 16a while ensuring anti-glare properties.

[0085] The ratio of the weight of the matrix resin in the antiglare layer to the total weight of the plurality of microparticles can be set as appropriate. In this embodiment, the ratio G2 / G1, where G1 is the weight of the matrix resin in the antiglare layer and G2 is the total weight of the plurality of microparticles contained in the antiglare layer, is set to a value in the range of 0.07 to 0.20. The ratio G2 / G1 is preferably a value in the range of 0.10 to 0.20, and more preferably a value in the range of 0.12 to 0.20.

[0086] The fine particles dispersed in the matrix resin may be either inorganic or organic, but those with good transparency are preferred. An example of an organic fine particle 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. Styrene beads may be cross-linked styrene beads, and acrylic beads may be cross-linked acrylic beads. Plastic beads preferably have hydrophobic groups on their surfaces. An example of such plastic beads is styrene beads.

[0087] Examples of the matrix resin 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.

[0088] 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.

[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's benzoyl benzoate, α-amyloxime ester, 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 known thermoplastic resins. Examples of such thermoplastic resins include styrene-based resins, (meth)acrylic resins, vinyl acetate-based resins, vinyl ether-based resins, halogen-containing resins, alicyclic olefin-based resins, polycarbonate-based resins, polyester-based resins, polyamide-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.).

[0092] When the material of the base film 2 is a cellulose-based resin such as triacetyl cellulose (TAC), the thermoplastic resin used as the solvent-drying resin can be a cellulose-based resin. Examples of the cellulose-based resin include cellulose derivatives such as nitrocellulose, acetyl cellulose, acetylbutyl cellulose, ethyl cellulose, methyl cellulose, cellulose acetate propionate, and ethylhydroxyethyl cellulose. By using a cellulose-based resin as the solvent-drying resin, the base film 2 and the antiglare layer 3 can be well adhered to each other, and an antiglare film 1 having 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 co-condensation resins, silicon resins, polysiloxane resins, etc. When a thermosetting resin is used as the matrix resin, 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.

[0095] As an example, the method for manufacturing the antiglare film in the second embodiment includes a preparation step of preparing a solution that serves as the raw material for the antiglare layer 3, an application step of applying the solution prepared in the preparation step to the surface of a predetermined support (in this embodiment, the base film 2), and a curing step of curing the resin in the applied solution.

[0096] [Preparation process] In the preparation step, a solution containing a solvent, a resin composition for forming the antiglare layer, and fine particles is prepared. Examples of the solvent include 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.

[0097] [Coating / curing process] 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 2) by the same method as in the first embodiment. The solvent is removed from the solution cast or coated on the surface of the support by evaporation through drying.

[0098] When the matrix resin is a photocurable resin, the coating step is followed by a curing step using, for example, ultraviolet light or electron beams. 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 ultraviolet light include a wavelength range of 190 nm to 380 nm.

[0099] 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.

[0100] The matrix resin contained in the solution hardens, fixing the positions of the particles in the matrix resin, resulting in the formation of an antiglare layer with a structure in which multiple particles are dispersed in the matrix resin and the particles form irregularities on the surface.

[0101] According to the anti-glare film of the second embodiment, by setting the difference in refractive index between the matrix resin and the microparticles within a predetermined range and dispersing multiple microparticles in the matrix resin, it is possible to suppress glare on the display 16a while ensuring good anti-glare properties and prevent discoloration of the anti-glare film.

[0102] Furthermore, since the ratio G2 / G1 of the antiglare layer is set to a value in the range of 0.07 or more and 0.20 or less, an antiglare film having an antiglare layer with a structure in which multiple microparticles are dispersed in a matrix resin can be successfully produced.

[0103] (Third embodiment) The antiglare layer 33 of the antiglare film according to the third embodiment has a structure in which a concave-convex shape is formed on the surface opposite to the substrate film side. The antiglare layer 33 is made of a resin layer. This resin layer is made of, for example, the same material as the matrix resin of the second embodiment.

[0104] Specifically, the antiglare film according to the third embodiment is produced by forming a coating layer containing a curable resin on a substrate film, shaping the surface of the coating layer into an uneven shape, and then curing the coating layer. Figure 2 is a diagram showing a method for producing the antiglare film according to the third embodiment. In the example of Figure 2, an ultraviolet-curable resin is used as the curable resin.

[0105] 2, in this manufacturing method, the base film 20a is unwound from a winding roll (not shown) and fed in a predetermined direction. The downstream end of the base film 20a in the feeding direction is inserted into a nip point N1 between a pair of rolls 21 and 22.

[0106] An ultraviolet-curable resin precursor is applied to the peripheral surface of the roll 22 from the peripheral surface of the roll 23, which is journaled adjacent to the roll 22. When the base film 20a passes through the nip point N1, the ultraviolet-curable 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 point N2 between the rolls 21 and 24. The roll 24 is a roll-shaped mold (embossing roll) with fine irregularities formed on its peripheral surface, and transfers the irregularities to the surface of the coating layer when passing through the nip point N2 between the rolls 21 and 24.

[0108] The coating layer, to the surface of which the uneven pattern has been transferred by roll 24, is cured by ultraviolet light irradiated from ultraviolet lamps 26 provided below rolls 21 and 24. This forms antiglare layer 33. Antiglare film 33 thus produced is released from roll 24 by roll 25, which is supported adjacent to roll 24, and is transported in a predetermined direction.

[0109] Here, the uneven portion on the surface of the roll 24 is formed by a blasting method in which blast particles of a predetermined particle size are struck against the roll 24, and by adjusting the particle size of the blast particles, the uneven shape formed on the coating layer of the antiglare film 33 can be adjusted.

[0110] The base film 20a can be suitably made of a PET (polyethylene terephthalate) film, a TAC (triacetyl cellulose) film, a COP (cycloolefin polymer) film, an acrylic resin film, or a polycarbonate resin film.

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

[0112] The average particle size of the blast particles used in step (b) can be set as appropriate, for example, to a value in the range of 10 μm to 50 μm. The average particle size of the blast particles is more preferably in the range of 20 μm to 45 μm, and even more preferably in the range of 30 μm to 40 μm. This results in an antiglare layer 33 having an uneven surface.

[0113] The mold used in the third embodiment may be other than a roll-shaped mold, and may be, for example, a plate-shaped mold (embossed plate). Alternatively, after forming a coating layer (resin layer) on one side of the substrate film, the surface of this coating layer may be shaped using a mold, and the coating layer may be cured to form the antiglare layer 33. In the above example, the surface of the coating layer is shaped, and then the coating layer is cured, but shaping and curing of the coating layer may be performed simultaneously.

[0114] Examples of the mold material include metal, plastic, and wood. A coating may be provided on the surface of the mold that comes into contact with the coating layer to improve the durability (wear resistance) of the mold. Examples of the blast particle material include metal, silica, alumina, and glass. The blast particles can be struck against the surface of the mold by gas or liquid pressure, for example. Furthermore, if the curable resin precursor is electron beam curable, an electron beam source such as an electron beam accelerator can be used instead of the ultraviolet lamp 26. If the curable resin precursor is heat curable, a heat source such as a heater can be used instead of the ultraviolet lamp 26.

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

[0116] The antiglare layer of the antiglare film according to each of the above embodiments may further have an upper layer disposed on the surface opposite to the substrate film 2. Providing this upper layer makes it easier to adjust the haze value of the antiglare layer and to protect the antiglare film from the outside.

[0117] The thickness of the upper layer can be set appropriately, for example, to a value in the range of 0.5 μm to 20 μm. The thickness of the upper layer is more preferably a value in the range of 2.0 μm to 12 μm, and even more preferably a value in the range of 3.0 μm to 8.0 μm. The glare inspection machine and glare evaluation method for inspecting and evaluating the antiglare films of each of the above-mentioned embodiments will be described below in order.

[0118] (Glare inspection machine) 3 is a schematic diagram of a glare inspection machine 10. The glare inspection machine 10 is a device for evaluating glare on a display 16a of a display device 16 having a film such as an anti-glare film attached to its surface, and includes a housing 11, an image capture device 12, a holding unit 13, an image capture device stand 14, a display device stand 15, and an image processing device 17. An example of a commercially available glare inspection machine 10 is the "Film Glare Inspector" manufactured by Komatsu NTC Ltd.

[0119] The housing 11 has a darkroom for capturing an image of the display 16a using the imaging device 12. The housing 11 accommodates the imaging device 12, a holder 13, an imaging device stand 14, a display device stand 15, and a display device 16 to be evaluated.

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

[0121] The holding unit 13 extends in the vertical direction and holds the imaging device 12 while being fixed at its lower end to the imaging device stand 14. The holding unit 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 relative to the display device 16 in the vertical direction.

[0122] The display device 16 is placed on the upper surface of the display device stand 15 with the display 16a with the film attached facing the imaging device 12. The display device stand 15 supports the display device 16 so that the surface of the display 16a with the film attached faces the imaging device 12 and is horizontal, and moves the display device 16 relative to the imaging device 12 in the 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., one pixel) of the imaging element 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 processes the image data captured by the imaging device 12. Specifically, the image processing device 17 obtains the standard deviation of the luminance of the display 16a from the image data captured by the imaging device 12.

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

[0126] When capturing an image displayed on display 16a using imaging device 12, the pixel size of the image captured per unit pixel (e.g., one pixel) of the imaging element can be adjusted by changing the relative distance between imaging device 12 and display 16a, or by changing the focal length of imaging device 12 if lens 18 provided in imaging device 12 is a zoom lens.

[0127] (Glare evaluation method) Next, we will explain the method for evaluating the glare of the display 16a using the glare tester 10. In this glare evaluation method, for the sake of convenience, the display 16a, which has a film attached to its surface, is made to emit uniform light in one color (green, for example) in advance.

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

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

[0130] After the adjustment step, a setting step is performed to set a measurement area for evaluating glare of the display 16a with the film attached. In the setting step, the measurement area is set appropriately depending on, 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 and the luminance of all pixels of the display 16a is adjusted so that image data is obtained as a grayscale image with an 8-bit gradation display and an average luminance 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 luminance variation in the measurement area of ​​the display 16a with the film attached. In this calculation step, the luminance variation is quantified as the standard deviation of the luminance distribution.

[0133] Here, the glare of the display 16a with the film attached increases as the luminance variation of the display 16a with the film attached increases. This allows quantitative evaluation that the smaller the standard deviation of the luminance distribution, the smaller the glare of the display 16a. Furthermore, in the adjustment step, the bright lines of the display 16a with the film attached are adjusted to a level that does not affect the evaluation of the glare of the display 16a, thereby suppressing luminance unevenness due to the bright lines and enabling an accurate evaluation of the glare of the display 16a.

[0134] By going through the above steps, the standard deviation of the luminance distribution of the display 16a with the film attached to its surface can be obtained, and the glare of the display 16a can be evaluated based on this value.

[0135] 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.

[0136] In Examples 1 to 4, an antiglare layer 3 having a phase-separated structure as a basic structure and containing predetermined components is formed. In Example 5, an antiglare layer is formed in which the haze value is increased by beads (silica fine particles). In Comparative Example 1, an antiglare layer is formed in which the haze value is increased by beads (zirconia fine particles). In Comparative Examples 2 and 3, an antiglare layer having a phase-separated structure is formed.

[0137] In Comparative Examples 4 and 5, an antiglare layer having an increased haze value was formed using beads (acrylic fine particles). In Comparative Example 6, an antiglare layer having an increased haze value was formed using beads (silica fine particles). In Comparative Examples 7 to 9, an antiglare layer having an increased haze value was formed using high refractive index beads (polystyrene fine particles, etc.). In Comparative Examples 10 and 11, an antiglare layer was formed by forming irregularities by embossing on the surface of a transparent resin applied to a substrate film. Note that the refractive indexes described in the following explanations of the Examples and Comparative Examples refer to the refractive index after crosslinking (curing) for those cured by crosslinking.

[0138] [Raw materials] The raw materials used in the examples and comparative examples are as follows: Acrylic polymer A having a polymerizable group: "Cyclomer P" manufactured by Daicel Allnex Co., Ltd., refractive index 1.51 Cellulose acetate propionate: Eastman "CAP-482-20", acetylation degree = 2.5%, propionylation degree = 46%, polystyrene equivalent number average molecular weight 75,000, refractive index 1.49 Silicone acrylate: Daicel Allnex "EB1360", refractive index 1.52 Urethane acrylate: "UA-53H" manufactured by Shin-Nakamura Chemical Co., Ltd. Dipentaerythritol hexaacrylate: "DPHA" manufactured by Daicel Allnex Co., Ltd., refractive index 1.52 Pentaerythritol tetraacrylate: "PETRA" manufactured by Daicel Allnex Co., Ltd., refractive index 1.52 Nanosilica-containing acrylic UV-curable compound A: "UVHC-7800" manufactured by Momentive Performance Materials Japan, LLC Silica (refractive index 1.46)-containing acrylic UV-curable compound: "Z-753-11R" manufactured by Aica Kogyo Co., Ltd., refractive index 1.52 Acrylic hard coat formulation A: "FA-3155 Clear" manufactured by Nippon Kako Toryo Co., Ltd., containing acrylic particles (refractive index 1.50) and matrix resin (refractive index 1.46) Acrylic hard coat compound B: "FA-3155M" manufactured by Nippon Kako Toryo Co., Ltd., refractive index 1.46 Fluorine-based compound A having a polymerizable group: "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd. Fluorine-based compound B having a polymerizable group: "Ftergent 602A" manufactured by Neos Co., Ltd. Zirconia fine particles (refractive index approx. 20) Dispersion: Toyo Ink Co., Ltd.'s "Lioduras TYZ" Photoinitiator A: "Irgacure 184" manufactured by BASF Japan Ltd. Photoinitiator B: "Irgacure 907" manufactured by BASF Japan Ltd. Polyethylene terephthalate (PET) film: "Diafoil" manufactured by Mitsubishi Plastics, Inc. Cellulose triacetate (TAC) film: Fujifilm Corporation's "Fujitac TG60UL"

[0139] [Example 1]

[0140] A solution was prepared by dissolving 12.5 parts by weight of acrylic polymer A having a polymerizable group, 4 parts by weight of cellulose acetate propionate, 150 parts by weight of nanosilica-containing acrylic ultraviolet-curable compound A, 1 part by weight of silicone acrylate, 1 part by weight of photoinitiator A, and 1 part by weight of photoinitiator B 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.

[0141] This solution was cast onto a PET film (substrate film 2) using a wire bar (#20), and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick.

[0142] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer 3 and obtaining the antiglare film of Example 1.

[0143] [Example 2] A solution was prepared by dissolving 15.0 parts by weight of acrylic polymer A having a polymerizable group, 3 parts by weight of cellulose acetate propionate, 150 parts by weight of nanosilica-containing acrylic ultraviolet-curable compound A, 1 part by weight of silicone acrylate, 1 part by weight of photoinitiator A, and 1 part by weight of photoinitiator B in a mixed solvent of 101 parts by weight of methyl ethyl ketone and 24 parts by weight of 1-butanol.

[0144] This solution was cast onto a PET film (substrate film 2) using a wire bar (#20), and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coating layer approximately 9 μm thick.

[0145] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer 3 and obtaining an antiglare film of Example 2.

[0146] [Example 3] A solution was prepared by dissolving 12.5 parts by weight of acrylic polymer A having a polymerizable group, 5.5 parts by weight of cellulose acetate propionate, 149.2 parts by weight of nanosilica-containing acrylic ultraviolet-curable compound A, 0.1 part by weight of fluorine-based compound B having a polymerizable group, 1 part by weight of photoinitiator A, and 1 part by weight of photoinitiator B in a mixed solvent of 129 parts by weight of methyl ethyl ketone, 24 parts by weight of 1-butanol, and 13 parts by weight of 1-methoxy-2-propanol.

[0147] This solution was cast onto a PET film (substrate film 2) using a wire bar (#16), and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coating layer approximately 7 μm thick.

[0148] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer 3 and obtaining an antiglare film of Example 3.

[0149] [Example 4] A solution was prepared by dissolving 50 parts by weight of acrylic polymer A having a polymerizable group, 2.5 parts by weight of cellulose acetate propionate, 79.5 parts by weight of urethane acrylate, 1 part by weight of silicone acrylate, 1 part by weight of photoinitiator A, and 1 part by weight of photoinitiator B in a mixed solvent of 106 parts by weight of methyl ethyl ketone, 28 parts by weight of 1-butanol, and 70 parts by weight of cyclohexanone.

[0150] This solution was cast onto a PET film (substrate film 2) using a wire bar (#12), and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coating layer approximately 5 μm thick.

[0151] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer 3 and obtaining an antiglare film of Example 4.

[0152] [Example 5] A solution was prepared by mixing 25 parts by weight of acrylic hard coat formulation A, 25 parts by weight of a silica-containing acrylic UV-curable compound, and 50 parts by weight of 1-butanol. This solution was cast onto a PET film (substrate film 2) using a wire bar (#16) and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coating layer approximately 7 μm thick. The coating layer was then irradiated with UV light from a UV lamp for approximately 5 seconds for UV curing, thereby forming antiglare layer 3, and the antiglare film of Example 5 was obtained.

[0153] [Comparative Example 1] A solution was prepared by dissolving 50 parts by weight of dipentaerythritol hexaacrylate, 50 parts by weight of pentaerythritol tetraacrylate, 100 parts by weight of zirconia microparticle dispersion, 2 parts by weight of photoinitiator A, and 1 part by weight of photoinitiator B 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.

[0154] This solution was cast onto a PET film (substrate film 2) using a wire bar (#14), and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coating layer approximately 6 μm thick.

[0155] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer and obtaining an antiglare film of Comparative Example 1.

[0156] Comparative Example 2 A solution was prepared by dissolving 5.7 parts by weight of acrylic polymer A having a polymerizable group, 1.2 parts by weight of cellulose acetate propionate, 4 parts by weight of dipentaerythritol hexaacrylate, 2.77 parts by weight of silicone acrylate, and 0.5 parts by weight of photoinitiator A in a mixed solvent of 25 parts by weight of methyl ethyl ketone and 12.2 parts by weight of 1-butanol.

[0157] This solution was cast onto a PET film (base film) using a wire bar (#24), and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coating layer approximately 7 μm thick.

[0158] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer and obtaining an antiglare film of Comparative Example 2.

[0159] Comparative Example 3 4.1 parts by weight of acrylic polymer A having a polymerizable group, 1.2 parts by weight of cellulose acetate propionate, 4 parts by weight of dipentaerythritol hexaacrylate, 2.77 parts by weight of silicone acrylate, and 0.5 parts by weight of photoinitiator A were dissolved in a mixed solvent of 25 parts by weight of methyl ethyl ketone and 12.2 parts by weight of 1-butanol. This solution was cast onto a PET film (substrate film) using a wire bar (#22) and then left in an oven at 100°C for 1 minute to evaporate the solvent, forming a coating layer approximately 6 μm thick.

[0160] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer and obtaining an antiglare film of Comparative Example 3.

[0161] Comparative Example 4 63 parts by weight of acrylic hard coat formulation A and 37 parts by weight of acrylic hard coat formulation B were mixed. This solution was cast onto a TAC film (substrate film) using a wire bar (#10), and then left in an oven at 100°C for 1 minute to evaporate the solvent and form a coating layer approximately 6 μm thick.

[0162] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer and obtaining an antiglare film of Comparative Example 4.

[0163] Comparative Example 5 32 parts by weight of acrylic hard coat formulation A and 68 parts by weight of acrylic hard coat formulation B were mixed. This solution was cast onto a TAC film (substrate film) using a wire bar (#10), and then left in an oven at 100°C for 1 minute to evaporate the solvent and form a coating layer approximately 6 μm thick.

[0164] The coating layer was then irradiated with ultraviolet light from a high-pressure mercury lamp for about 5 seconds to cure the coating layer, thereby forming an antiglare layer and obtaining an antiglare film of Comparative Example 5.

[0165] Comparative Example 6 A 125 μm-thick transparent polyester film (Cosmoshine A4300, manufactured by Toyobo Co., Ltd.) was used as the substrate film. Opstar Z7501 (manufactured by JSR Corporation, 50% solids), an organic-inorganic hybrid ionizing radiation-curable resin composition, was used as the transparent resin. 8.5 parts of OK-500 translucent silica particles (manufactured by Degussa, average particle size 3.0 μm, refractive index 1.46) were added to 200 parts by weight of the transparent resin. One part by weight of Irgacure 651 (manufactured by BASF) was added as a photopolymerization initiator, and 200 parts by weight of butyl acetate (boiling point 100°C) was added as a solvent. The resulting resin composition was then coated onto the substrate film and dried for 1 minute by circulating dry air at 85°C at a flow rate of 1 m / s.

[0166] This was irradiated with ultraviolet light (200 / cm under a nitrogen atmosphere). 2 The transparent resin was cured to form an antiglare layer, thereby obtaining an antiglare film of Comparative Example 6. The coating thickness was 6 μm.

[0167] Comparative Example 7 Triacetyl cellulose (Fujifilm Corporation, 80 μm thick) was used as the substrate film. Pentaerythritol triacrylate (PETA; Daicel-Allnex Corporation, refractive index 1.51) was used as the transparent resin. Styrene-acrylic copolymer particles (refractive index 1.51, average particle size 9.0 μm) and polystyrene particles (refractive index 1.60, average particle size 3.5 μm) were added as translucent particles at 10.0 parts by weight and 16.5 parts by weight per 100 parts by weight of the transparent resin. A mixed solvent of toluene (boiling point 110 °C) and cyclohexanone (boiling point 156 °C) (7:3 weight ratio) was added as the solvent at 190 parts by weight per 100 parts by weight of the transparent resin. The resulting resin composition was then coated onto the substrate film and dried for 1 minute by passing dry air at 85 °C at a flow rate of 1 m / s.

[0168] This was irradiated with ultraviolet light (200 / cm under a nitrogen atmosphere). 2 The transparent resin was cured to form an antiglare layer, thereby obtaining an antiglare film of Comparative Example 7. The coating thickness was 5 μm.

[0169] [Comparative Example 8] A triacetyl cellulose (Fujifilm, 80 μm thick) substrate film was prepared. A mixture of pentaerythritol triacrylate (PETA; Daicel-Allnex), dipentaerythritol hexaacrylate (DPHA; Daicel-Allnex), and polymethyl methacrylate (BR85; Mitsubishi Rayon) (weight ratio: PETA / DPHA / PMMA = 86 / 5 / 9) was used as the transparent resin (refractive index: 1.51). Translucent particles were added to the transparent resin in amounts of 18.5 and 3.5 parts by weight, respectively, of polystyrene particles (refractive index: 1.60, average particle size: 3.5 μm) and styrene-acrylic copolymer particles (refractive index: 1.56, average particle size: 3.5 μm) per 100 parts by weight of the transparent resin. A mixed solvent (weight ratio 7:3) of toluene (boiling point 110°C) and cyclohexanone (boiling point 156°C) was added as a solvent to the transparent resin in an amount of 190 parts by weight per 100 parts by weight of the resin. The resin composition was then applied to the substrate film, and dried for 1 minute by passing dry air at 70°C through the film at a flow rate of 0.2 m / s.

[0170] Then, ultraviolet light was irradiated (200 mJ / cm under a nitrogen atmosphere). 2 The transparent resin was cured to form an antiglare layer, thereby obtaining an antiglare film of Comparative Example 8. The coating thickness was 3.5 μm.

[0171] Comparative Example 9 Triacetyl cellulose (Fujifilm Corporation, 80 μm thick) was used as the substrate film. Pentaerythritol triacrylate (PE-3A; Kyoeisha Chemical Co., Ltd., refractive index 1.53) was used as the transparent resin. The translucent particles were silica particles (SS50F; Tosoh Silica Industries Co., Ltd., refractive index 1.47, average particle size 1.1 μm) and polystyrene particles (refractive index 1.59, average particle size 3.5 μm), with 26 parts by weight and 6.6 parts by weight, respectively, per 100 parts by weight of the transparent resin. 5.3 parts by weight of Irgacure 184 (BASF) as a photopolymerization initiator and 138 parts by weight of toluene (boiling point 110 °C) as a solvent were blended into the resin composition. The resulting resin composition was then coated onto the substrate film and dried for 1 minute by passing dry air at 90 °C at a flow rate of 0.2 m / s.

[0172] Then, ultraviolet light was irradiated (200 mJ / cm under a nitrogen atmosphere). 2 The transparent resin was cured to form an antiglare layer, thereby obtaining an antiglare film of Comparative Example 9. The coating thickness was 5 μm.

[0173] [Comparative Examples 10 and 11] The antiglare films of Comparative Examples 10 and 11 were produced by forming, on a substrate film, a coating layer made of an ultraviolet curable resin with a surface pattern transferred thereon using a mold, as shown in FIG.

[0174] That is, in Example 5 and Comparative Examples 2 to 5, as shown in FIG. 3, the base film 20a, which was unwound from an unwinding roll (not shown) and transported, was inserted into the nip point between a pair of rolls 21 and 22, and an ultraviolet-curable resin precursor was adhered to the peripheral surface of roll 22 from the peripheral surface of roll 23, which was journaled adjacent to roll 22, and this ultraviolet-curable resin precursor was applied to the upper surface of the base film 20a.

[0175] The applied ultraviolet curable resin precursor was pressed together with the base film 20a at the nip point N1 between the rolls (roll-shaped molds) 21 and 24. As a result, when the applied ultraviolet curable resin precursor passed through the nip point N1 between the rolls 21 and 24 together with the base film 20a, a concave-convex shape was transferred to the surface of the ultraviolet curable resin precursor.

[0176] The ultraviolet-curable resin precursor to which the uneven pattern was transferred by roll 24 was cured by ultraviolet light irradiated from UV lamps installed below rolls 21 and 24 to form a coating layer (antiglare layer). The antiglare film thus obtained was released from roll 24 by roll 25, which was axially supported adjacent to roll 24, and transported in a predetermined direction. A TAC (triacetyl cellulose) film was used as the substrate film.

[0177] In step (b) of producing a roll-shaped mold having an uneven surface by impacting the blast particles, the blast particle size was varied in the range of 30 μm to 40 μm to produce the roll-shaped mold. Two types of films (Comparative Examples 10 and 11) with different haze (Hz) values ​​were produced by the above production method.

[0178] Next, the antiglare films of Examples 1 to 5 and Comparative Examples 1 to 11 were measured and evaluated for the following items. The adhesive layer was omitted when measuring haze, total light transmittance, transmitted image clarity, and 60-degree gloss.

[0179] [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. The haze was measured by placing the surface of the antiglare layer having the uneven structure facing the light receiver.

[0180] [Transmission image clarity] Measurements were performed using a projection measuring instrument (ICM-1T, manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7105, with the antiglare film positioned so that the film-forming direction of the antiglare film was parallel to the direction of the teeth of the optical comb. The optical comb width was 0.5 mm.

[0181] [60° Gloss] Measurement was carried out at an angle of 60° using a gloss meter (IG-320, manufactured by Horiba Seisakusho Co., Ltd.) in accordance with JIS K7105.

[0182] [Standard deviation of display luminance distribution (glare value)] A smartphone (Samsung Electronics Co., Ltd.'s "Galaxy S4") was used as the display device 16, and each sample anti-glare film was attached to the surface of its display 16a using an adhesive layer (optical glue). Using a film glare tester 10 manufactured by Komatsu NTC Corporation, the standard deviation of the luminance distribution of the display 16a (glare σ: glare value) was measured through each sample anti-glare film. During this measurement, at least either the exposure time of the imaging device 12 or the luminance of all pixels of the display 16a was adjusted so that image data was obtained as a grayscale image with an 8-bit gradation display and an average luminance of 170 gradations. The measurement results are shown in Tables 1 and 2.

[0183] [Table 1]

[0184] [Table 2]

[0185] As shown in Table 1, the antiglare films 1 of Examples 1 to 5 have a transmitted image clarity of 3% or more and 40% or less at an optical comb width of 0.5 mm, and the haze value of the antiglare layer 3 is set to a value of 55.5% or more and 93.0% or less. Furthermore, the antiglare films of Examples 1 to 5 have a glare value (glare σ) of the display 16a that is suppressed to a value of 4.2 or more and 6.0 or less. That is, it was found that the antiglare films 1 of Examples 1 to 5 have good antiglare properties while suppressing the glare value of the display.

[0186] The reason for this is thought to be that in the antiglare layer 3 of Examples 1 to 4, phase separation occurs between the acrylic copolymer A and the cellulose acetate propionate, and the phase separation structure is emphasized by the nanosilica-containing acrylic ultraviolet-curable compound A and the urethane acrylate, making it possible to form the surface of the antiglare layer 3 into a structure with very steep or uneven surfaces.

[0187] In other words, it is believed that the nanosilica-containing acrylic ultraviolet-curable compound A and urethane acrylate have high affinity for acrylic copolymer A, and repulsive interactions occur with cellulose acetate propionate, thereby emphasizing the phase separation structure of the antiglare layer 3 in Examples 1 to 4.

[0188] Furthermore, in the antiglare layer 3 of Example 5, the addition of a large amount of butanol, a solvent with low affinity for the silica particles in the silica-containing acrylic UV-curable compound, is thought to have caused severe aggregation of the silica particles, thereby forming a very steep or uneven structure on the surface of the antiglare layer 3. In other words, it is thought that the repulsive interaction between the silica particles and butanol accentuated the uneven structure formed on the surface of the antiglare layer 3 to an extent that would not have been achieved with a solvent with high affinity. Furthermore, in the antiglare layer 3 of Example 5, the coexistence of the acrylic UV-curable resin and the acrylic hard coat formulation A made it possible to adjust the optical performance to the ranges shown in Table 1.

[0189] As shown in Tables 1 and 2, Comparative Examples 1 to 6 and 11 have relatively high values ​​for clarity of transmitted image and 60-degree gloss compared to Examples 1 to 5. Comparative Examples 7 to 9 have relatively low values ​​for clarity of transmitted image but relatively high values ​​for 60-degree gloss, and Comparative Example 10 has relatively low values ​​for 60-degree gloss but relatively high values ​​for clarity of transmitted image. As such, Comparative Examples 1 to 11 have a poorer balance between clarity of transmitted image and 60-degree gloss compared to Examples 1 to 5, which is thought to be why they have lower antiglare properties compared to Examples 1 to 5.

[0190] Specifically, the antiglare film of Comparative Example 1 has a configuration in which the haze value of the antiglare layer is increased by using beads (zirconia fine particles), and the difference in refractive index between the beads and the matrix resin contained in the antiglare layer is set to 0.2. However, as shown in Table 2, although the antiglare film of Comparative Example 1 suppresses the glare value of the display to some extent, the values ​​of transmitted image clarity and 60-degree gloss are high, indicating that it does not have excellent antiglare properties.

[0191] The antiglare films of Comparative Examples 2 and 3 have an antiglare layer formed by a phase-separated structure, but since the phase-separated structure of the antiglare layer is not emphasized as in Examples 1 to 4, it was found that the antiglare properties are not superior compared to Examples 1 to 4.

[0192] In Comparative Examples 4 to 6, the difference in refractive index between the beads contained in the antiglare layer and the matrix resin was small, so it was difficult to increase the haze value compared to Examples 1 to 5, and it was found that it was difficult to obtain good antiglare properties while suppressing the glare value of the display.

[0193] In Comparative Examples 7 to 9, the haze value of the antiglare layer is increased to some extent by adjusting the internal haze value of the antiglare layer using high refractive index beads (polystyrene microparticles, etc.). However, it was found that it was difficult to obtain good antiglare properties while suppressing the glare value of the display, as in Examples 1 to 5.

[0194] Comparative Examples 10 and 11 have antiglare layers with embossed surface irregularities, but it was found that it was difficult to obtain good antiglare properties while suppressing the glare value of the display, as in Examples 1 to 5.

[0195] Furthermore, based on the trends in the characteristics shown in Examples 1 to 5 and other studies conducted by the inventors of the present application, it is believed that the same effects as in Examples 1 to 5 will be achieved even when the glare value of the display 16a is set to a value in the range of 0 or more and less than 4.2, the transmitted image clarity of the antiglare film 1 with an optical comb width of 0.5 mm is set to a value in the range of 0% or more and less than 8.4% and 55% or more and 60% or less, and the haze value of the antiglare layer 3 is set to a value in the range of 50% or more and less than 55.5 and 93.0 or more and 99.0% or less.

[0196] The present invention is not limited to the above-described embodiments, and the configurations or methods thereof can be changed, added, or deleted without departing from the spirit of the present invention. [Explanation of symbols]

[0197] 1. Anti-glare film 3 Anti-glare layer 16a Display

Claims

1. an antiglare layer containing a matrix resin and a plurality of fine particles including nanosilica, and having a haze value in the range of 55.5% to 99%; a substrate film disposed on the antiglare layer, The 60-degree gloss is a value in the range of 0.9% or more and 30% or less, An antiglare film, wherein the antiglare layer does not include any organic fine particles or a phase-separated structure, and the surface of the matrix resin has irregularities formed by the plurality of fine particles in the matrix resin.

2. The antiglare film according to claim 1 , wherein the matrix resin includes at least one of a photocurable resin, a thermoplastic resin, and a thermosetting resin.

3. 3. The antiglare film according to claim 1, wherein the difference in refractive index between the fine particles and the matrix resin is in the range of 0 to 0.

07.

4. The antiglare film according to any one of claims 1 to 3, wherein a ratio G2 / G1 of a weight G1 of the matrix resin of the antiglare layer to a total weight G2 of the plurality of fine particles contained in the antiglare layer is a value in the range of 0.07 to 0.20.

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