Anti-glare film

Abstract

To provide an antiglare film that appropriately suppresses glare on a display and has good antiglare properties. [Solution] The antiglare film is an antiglare film to be attached to the surface of a display, and is provided with an antiglare layer set to a value such that the glare value, defined based on the standard deviation of the luminance distribution of the display when attached to the surface of the display, is a value in the range of 10 or less, the specular gloss measured at 60-degree specular gloss is a value in the range of 40% or less, and the transmitted image clarity at an optical comb width of 0.5 mm is a value in the range of 40% or less. This allows the film to appropriately suppress glare on the display and has good antiglare properties.

Description

Technical Field

[0001] The present invention relates to an antiglare film for preventing external light from reflecting on the display surface.

Background Art

[0002] An antiglare film is, for example, a film having a roughened surface with irregularities, which is attached to the surface of a display and scatters external light to prevent the external light from reflecting on the display.

[0003] As a method of forming irregularities on the surface of an antiglare film, for example, as disclosed in Patent Document 1, a method of dispersing fine particles (fillers) in a matrix resin (hereinafter referred to as the fine particle dispersion method), or as disclosed in Patent Document 2, a method of utilizing a phase separation structure formed by spinodal decomposition from a liquid phase of a plurality of polymers (hereinafter referred to as the phase separation method), or as disclosed in Patent Document 3, a method of transferring and molding an irregular shape with a mold (hereinafter referred to as the transfer molding method), etc. can be mentioned.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] When an antiglare film is attached to the surface of a display, while the reflection of external light on the display is prevented, the display performance of the display through the antiglare film may deteriorate.

[0006] In particular, when an antiglare film is attached to the surface of a display having high-definition pixels, etc., the light from the display transmitted through the antiglare film is refracted by the unevenness on the surface of the antiglare film, or the pixels of the display appear enlarged due to the lens effect caused by the unevenness on the surface of the antiglare film, resulting in glare and making the image difficult to view.

[0007] As a method for suppressing glare, for example, it is conceivable to reduce the unevenness on the surface of the antiglare film. However, reducing the unevenness on the surface of the antiglare film may reduce the antiglare property.

[0008] Therefore, an object of the present invention is to provide an antiglare film that appropriately suppresses the glare of a display and has good antiglare properties.

Means for Solving the Problem

[0009] An antiglare film according to an aspect of the present invention is an antiglare film attached to the surface of a display, and has a glare value defined based on the value of the standard deviation of the luminance distribution of the display in a state of being attached to the surface of the display within a range where the value is 10 or less, a specular glossiness measured at 60-degree specular gloss within a range where the value is 40% or less, and a transmission image sharpness with an optical comb width of 0.5 mm within a range where the value is 40% or less, and is provided with an antiglare layer set to a value within this range.

[0010] Here, the glare value is a value that serves as an objective index for quantitatively evaluating the glare of a display. Specifically, the glare value is a value defined based on the value of the standard deviation of the luminance distribution of the display, and indicates the degree of variation of the bright spots on the display.

[0011] In addition, the transmission sharpness is a value related to the quality of the antiglare property, and there is a relationship that the smaller the transmission sharpness, the higher the antiglare property.

[0012] These glare values, specular gloss, and transmitted image sharpness can be achieved, for example, when forming an antiglare layer by the phase separation method, by adjusting, in the manufacturing process, the type of phase separation materials to be combined, or the heating temperature of the composition in the drying process, the air volume of the drying air blown onto the composition, or the linear velocity. Further, for example, when forming an antiglare layer by the fine particle dispersion method, it can be achieved by adjusting, in the manufacturing process, the difference between the refractive index of the matrix resin and the refractive indices of a plurality of fine particles dispersed in the matrix resin to be within a predetermined range. Further, in order to make the refractive index difference between the matrix resin and the fine particles within a predetermined range, as materials used for both, materials having a predetermined refractive index difference are selected, or the shape, number, density of the fine particles contained in the matrix resin, etc. are adjusted. Furthermore, the value of the ratio G2 / G1 of the weight G1 of the matrix resin to the total weight G2 of the plurality of fine particles is adjusted.

[0013] According to the above configuration, since the antiglare layer has a value in the range where the glare value is 10 or less, it can be set so as to effectively suppress glare based on quantitative evaluation.

[0014] Further, the antiglare layer is set to have a value in the range where the transmitted image sharpness is 40% or less. For this reason, the antiglare layer can obtain high antiglare performance regardless of the magnitude of the haze value, which is another index related to the quality of antiglare performance.

[0015] Furthermore, since it is set to have a value in the range where the specular gloss measured at 60-degree specular gloss is 40% or less, reflection of external light can be suppressed.

[0016] Therefore, the antiglare film according to an aspect of the present invention has an effect of appropriately suppressing the glare of the display and having good antiglare performance.

[0017] Further, in the antiglare film according to an aspect of the present invention, in the above-described configuration, 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.

[0018] Further, in a certain form of the present invention, the antiglare film includes, in the above-described configuration, the antiglare layer including 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 0.07 or less.

[0019] In this way, 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 appropriately suppress the glare of the display and have good antiglare properties.

[0020] Further, in a certain form of the present invention, the antiglare film includes, in the above-described configuration, 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 included in the antiglare layer may be a value in the range of 0.03 or more and 0.20 or less.

[0021] Thereby, it is possible to favorably manufacture an antiglare film having an antiglare layer with a structure in which a plurality of fine particles are dispersed in a matrix resin.

Effect of the Invention

[0022] As described above, the present invention is configured, and the antiglare film has an effect of being able to appropriately suppress the glare of the display and having good antiglare properties.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0024] Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of the antiglare film 1 according to an embodiment of the present invention. The antiglare film 1 is attached to the surface of the display 16a of the display device 16 (see FIG. 3). The antiglare film 1 includes a base film 2, an antiglare layer 3, and an adhesive layer 4.

[0025] The base film 2 is disposed between the surface of the display 16a and the antiglare layer 3 and supports the antiglare layer 3. The adhesive layer 4 is disposed between the surface of the display 16a and the base film 2 and fixes the antiglare film 1 to the surface of the display 16a.

[0026] 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, scatters and reflects external light, and prevents external light from being reflected into the display 16a. The antiglare layer 3 also functions as a hard coat (HC) layer that covers the surface of the base film 2. The antiglare layer 3 includes, for example, a plurality of resin components that can be phase-separated.

[0027] The antiglare layer 3 is set to have a value in a range where the glossiness value is 10 or less. The glossiness value is defined based on the value of the standard deviation of the luminance distribution of the display 16a when the antiglare film 1 is attached to the surface of the display 16a. This glossiness value can be obtained using a glossiness inspection machine 10 described later.

[0028] Further, the antiglare layer 3 is set to have a value in a range where the transmission image sharpness (image sharpness) with an optical comb width of 0.5 mm is 40% or less. The transmission image sharpness is a measure for quantifying the blur and distortion of the light transmitted through the antiglare layer 3 and is a value measured by a measurement method conforming to JIS K7105.

[0029] In addition, the antiglare layer 3 is set to a value in the range where the glossiness (60-degree gloss) measured at 60-degree specular gloss is 20% or less. The glossiness is generally called luster and is a value representing the degree of specular reflected light on the surface of an object, and is a value measured in accordance with JIS K7136. Note that there is no particular limitation on the range of possible values of the haze value of the antiglare layer 3.

[0030] Thus, the antiglare film 1 according to this embodiment can be designed so that the glare value, which is a quantitative evaluation of objective glare, is in the range of 10 or less. Therefore, for example, compared with the case of designing based on a value indicating the degree of glare by subjective evaluation, glare can be stably suppressed to be within a desired range.

[0031] In addition, the transmission clarity can be suppressed to a value in the range of 40% or less. Therefore, the antiglare layer 3 can obtain high antiglare performance regardless of the magnitude of the haze value, which is another index related to the quality of antiglare performance.

[0032] In addition, since the glossiness (60-degree gloss) measured at 60-degree specular gloss of the antiglare layer 3 is set to a value in the range of 40% or less, the reflection of light on the surface of the display 16a can be suppressed.

[0033] The adhesive layer 4 is disposed between the surface of the display 16a and the base film 2, and fixes the antiglare film 1 to the surface of the display 16a.

[0034] Hereinafter, specific examples of the base film 2 and the antiglare layer 3 will be described. The antiglare layer 3 formed by the phase separation method is used as the antiglare layer 3 according to the first embodiment, the antiglare layer 3 formed by the fine particle dispersion method is used as the antiglare layer 3 according to the second embodiment, and the antiglare layer 3 formed by the transfer molding method is used as the antiglare layer 3 according to the third embodiment, and each will be described.

[0035] [Base Film] Examples of the material of the base film 2 include glass, ceramics, and resin. As the resin, the same resin as that of the antiglare layer 3 can be used. Preferred materials for the base film 2 include transparent polymers such as cellulose derivatives (such as cellulose acetate including cellulose triacetate (TAC) and cellulose diacetate), polyester resins (such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polyarylate resins), polysulfone resins (such as polysulfone and polyethersulfone (PES)), polyether ketone resins (such as polyether ketone (PEK) and polyether ether ketone (PEEK)), polycarbonate resins (PC), polyolefin resins (such as polyethylene and polypropylene), cyclic polyolefin resins (such as the film "ARTON" (registered trademark) manufactured by JSR Corporation and the film "ZEONEX" (registered trademark) manufactured by Nippon Zeon Co., Ltd.), 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).

[0036] The base film 2 may be uniaxially or biaxially stretched, but is preferably optically isotropic and has a low refractive index. Examples of the optically isotropic base film 2 include unstretched films.

[0037] The thickness dimension of the base film 2 can be set as appropriate. For example, it is preferably a value in the range of 5 μm or more and 2000 μm or less, more preferably in the range of 15 μm or more and 1000 μm or less, and still more preferably a value in the range of 20 μm or more and 500 μm or less.

[0038] (First Embodiment) [Structure of the Antiglare Layer According to the First Embodiment] The antiglare layer 3 according to the first embodiment has a phase separation structure of a plurality of resin components. The antiglare layer 3 according to the first embodiment, as an example, has a structure in which a plurality of elongated (string-like or linear) convex portions are formed on the surface due to the phase separation structure of the plurality of resin components. The elongated convex portions are branched and form a co-continuous phase structure in a dense state.

[0039] The antiglare layer 3 according to the first embodiment exhibits antiglare properties due to a plurality of elongated convex portions and concave portions located between adjacent elongated convex portions. By providing such an antiglare layer 3, the antiglare film 1 has an excellent balance between the haze value and the sharpness of the transmitted image. The surface of the antiglare layer 3 according to the first embodiment has a mesh-like structure, that is, an irregular plurality of loop structures that are continuous or partially missing, due to the formation of the elongated convex portions in a substantially mesh shape.

[0040] By forming such a structure in the antiglare layer 3 according to the first embodiment, it is possible to prevent the formation of lens-shaped (island-shaped) convex portions in the antiglare layer 3. Therefore, light from the display 16a transmitted through the antiglare layer 3 according to the first embodiment is prevented from being refracted by the unevenness on the surface of the antiglare layer 3 or from the pixel of the display 16a being enlarged and seen due to the lens effect of the unevenness on the surface of the antiglare layer 3, and the glare of the display 16a can be suppressed. As a result, even when the antiglare film 1 is attached to a display 16a having high-definition pixels, glare can be highly suppressed while ensuring antiglare properties, and blurring of characters and the like can also be suppressed.

[0041] Note that the plurality of elongated convex portions may be independent or connected. As will be described later, the phase separation structure of the antiglare layer 3 according to the first embodiment is formed by spinodal decomposition (wet spinodal decomposition) from the liquid phase using a solution that is the raw material of the antiglare layer 3. For details of the antiglare layer 3 according to the first embodiment, for example, reference can be made to the description in Patent Document 4.

[0042] [Material of the antiglare layer according to the first embodiment] The plurality of resin components included in the antiglare layer 3 according to the first embodiment may be those capable of phase separation. From the viewpoint of obtaining the antiglare layer 3 in which elongated convex portions are formed and which has high scratch resistance, the plurality of resin components included in the antiglare layer 3 preferably include a polymer and a curable resin.

[0043] Examples of the polymer included in the antiglare layer 3 according to the first embodiment include thermoplastic resins. Examples of the thermoplastic resin include styrene resins, (meth)acrylic resins, vinyl esters of organic acids, vinyl ether resins, halogen-containing resins, olefin resins (including alicyclic olefin resins), polycarbonate resins, polyester resins, polyamide resins, thermoplastic polyurethane resins, polysulfone resins (such as polyethersulfone and polysulfone), polyphenylene ether resins (such as polymers of 2,6-xylenol), cellulose derivatives (such as cellulose esters, cellulose carbamates, and cellulose ethers), silicone resins (such as polydimethylsiloxane and polymethylphenylsiloxane), and rubbers or elastomers (such as diene rubbers such as polybutadiene and polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic rubbers, urethane rubbers, and silicone rubbers). These thermoplastic resins can be used alone or in combination of two or more.

[0044] Examples of the polymer also include those having a functional group involved in a curing reaction or a functional group that reacts with a curable compound. This polymer may have the functional group in the main chain or the side chain.

[0045] Examples of the functional group include a condensable group, a reactive group (for example, a hydroxyl group, an acid anhydride group, a carboxyl group, an amino group or an imino group, an epoxy group, a glycidyl group, an isocyanate group, etc.), and a polymerizable group (for example, a C 2-6 alkenyl group such as vinyl, propenyl, isopropenyl, butenyl, and allyl groups, a C 2-6 alkynyl group such as ethynyl, propynyl, and butynyl groups, and a C 2-6Examples include alkenylidene groups and groups having these polymerizable groups ((meth)acryloyl groups, etc.). Among these functional groups, polymerizable groups are preferred.

[0046] In addition, the antiglare layer 3 according to the first embodiment may contain a plurality of types of polymers. Each of 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 plurality of types of polymers is not particularly limited, but those that are incompatible with each other near the processing temperature can be used.

[0047] 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, cellulose esters such as cellulose acetate propionate), a (meth)acrylic-based resin (polymethyl methacrylate, etc.), an alicyclic olefin-based resin (a polymer having norbornene as a monomer, etc.), a polycarbonate-based resin, and a polyester-based resin (poly C 2-4 alkylene arylate copolyesters, etc.).

[0048] Also, when the first polymer is a cellulose derivative (for example, cellulose esters such as cellulose acetate propionate), the second polymer may be a styrene-based resin (polystyrene, styrene-acrylonitrile copolymer, etc.), a (meth)acrylic-based resin, an alicyclic olefin-based resin (a polymer having norbornene as a monomer, etc.), a polycarbonate-based resin, and a polyester-based resin (poly C 2-4 alkylene arylate copolyesters, etc.).

[0049] The plurality of types of polymers may contain at least cellulose esters (for example, cellulose C 2-4 alkyl carboxylic acid esters) such as cellulose diacetate, cellulose triacetate, cellulose acetate propionate, and cellulose acetate butyrate.

[0050] Here, the phase separation structure of the antiglare layer 3 according to the first embodiment is fixed by curing a precursor of a curable resin contained in a plurality of resin components by active energy rays (such as ultraviolet rays and electron beams) or heat or the like during the production of the antiglare layer 3. Further, such a curable resin imparts scratch resistance and durability to the antiglare layer 3 according to the first embodiment.

[0051] From the viewpoint of obtaining scratch resistance, at least one polymer contained in a plurality of types of polymers is preferably a polymer having a functional group capable of reacting with a curable resin precursor in a side chain. As the polymers forming the phase separation structure, in addition to the two polymers that are incompatible with each other described above, a thermoplastic resin or other polymers may be included. The mass ratio M1 / M2 of the mass M1 of the first polymer and the mass M2 of the second polymer and the glass transition temperature of the polymer can be set as appropriate.

[0052] Examples of the curable resin precursor include curable compounds having a functional group that reacts with active energy rays (such as ultraviolet rays and electron beams) or heat or the like, and forming a resin (particularly a cured resin or a crosslinked resin) by curing or crosslinking with this functional group.

[0053] 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, and a silanol group, etc. (for example, epoxy resins, unsaturated polyester resins, urethane resins, silicone resins, etc.)), or photocurable (ionizing radiation curable) compounds (such as ultraviolet curable compounds such as photocurable monomers and oligomers) that are cured by ultraviolet rays or electron beams or the like.

[0054] Preferred curable resin precursors include photocurable compounds that cure in a short time by ultraviolet rays, electron beams, or the like. Among 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.

[0055] 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 amines or polyvalent carboxylic acids, and the photocurable resin precursor may contain a photoinitiator. Examples of the photoinitiator include conventional components such as acetophenones or propiophenones, benzyls, benzoins, benzophenones, thioxanthones, and acylphosphine oxides.

[0056] In addition, the curable resin precursor may contain a curing accelerator. For example, the photocurable resin precursor may contain a photocuring accelerator (e.g., tertiary amines (such as dialkylaminobenzoic acid esters)) and phosphine-based photopolymerization accelerators.

[0057] In the manufacturing process of the antiglare layer 3 according to the first embodiment, among the polymer and the curable resin precursor contained in the solution serving as the raw material of the antiglare layer 3, at least two components are used as a combination that phase-separates from each other near the processing temperature. Examples of the combination for phase separation include (a) a combination in which multiple types of polymers are incompatible with each other and phase-separate, (b) a combination in which a polymer and a curable resin precursor are incompatible and phase-separate, and (c) a combination in which multiple curable resin precursors are incompatible with each other and phase-separate. Among these combinations, usually, (a) a combination of multiple types of polymers or (b) a combination of a polymer and a curable resin precursor are mentioned, and particularly (a) a combination of multiple types of polymers is preferred.

[0058] Here, usually, the refractive index of a polymer is different from that of the cured resin or crosslinked resin formed by curing the curable resin precursor. Also, usually, the refractive indices of multiple types of polymers (the first polymer and the second polymer) are different from each other. The difference in refractive index between the polymer and the cured resin or crosslinked resin, and the difference in refractive index between multiple types of polymers (the first polymer and the second polymer) are desirably values in the range of, for example, 0 or more and 0.2 or less, and more desirably values in the range of 0 or more and 0.07 or less.

[0059] Further, the antiglare layer 3 may contain a plurality of fine particles (fillers) dispersed in the matrix resin. The fine particles may be either organic fine particles or inorganic fine particles, and the plurality of fine particles may include multiple types of fine particles.

[0060] Examples of the organic fine particles include crosslinked acrylic particles and crosslinked styrene particles. Examples of the inorganic fine particles include silica particles and alumina particles. Also, as an example, the difference in refractive index between the fine particles contained in the antiglare layer 3 and the matrix resin can be set to a value in the range of 0 or more and 0.2 or less. This difference in refractive index is more desirably a value in the range of 0 or more and 0.15 or less, and even more desirably a value in the range of 0 or more and 0.07 or less.

[0061] The average particle size of the fine particles is not particularly limited and can be set, for example, to a value in the range of 0.5 μm or more and 5.0 μm or less. It is more desirable that this average particle size is a value in the range of 0.5 μm or more and 4.0 μm or less, and even more desirable that it is a value in the range of 1.0 μm or more and 3.0 μm or less.

[0062] 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 fine particles may be solid or hollow. Care should be taken because 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 that the display will flicker significantly.

[0063] The thickness dimension of the anti-glare layer 3 according to the first embodiment can be set as appropriate, but for example, it is desirable that it is a value in the range of 0.3 μm or more and 20 μm or less, more desirable that it is a value in the range of 1 μm or more and 15 μm or less, and even more desirable that it is a value in the range of 1 μm or more and 10 μm or less. Usually, it can be set to a value in the range of 2 μm or more and 10 μm or less (particularly a value in the range of 3 μm or more and 7 μm or less).

[0064] Note that an anti-glare film omitting the base film 2 can also be configured. In this case, the thickness dimension of the anti-glare layer 3 is, for example, desirably a value in the range of 1 μm or more and 100 μm or less, and more desirably a value in the range of 3 μm or more and 50 μm or less.

[0065] The anti-glare layer 3 according to the first embodiment may contain conventional additives, such as organic or inorganic particles, stabilizers (antioxidants, ultraviolet absorbers, etc.), surfactants, water-soluble polymers, fillers, cross-linking agents, coupling agents, colorants, flame retardants, lubricants, waxes, preservatives, viscosity modifiers, thickeners, leveling agents, and defoaming agents, etc., as long as the optical properties are not impaired.

[0066] The manufacturing method of the anti-glare film 1 according to the first embodiment, as an example, includes a preparation step of preparing a solution (hereinafter, also simply referred to as a solution) that serves as a raw material for the anti-glare layer 3 according to the first embodiment, and applying the solution prepared in the preparation step to the surface of a predetermined support (the base film 2 in the first embodiment), evaporating the solvent in the solution, and forming a phase separation structure by spinodal decomposition from the liquid phase, and a curing step of curing the curable resin precursor after the forming step.

[0067] [Preparation Step] In the preparation step, a solution containing a solvent and a resin composition for forming the anti-glare layer 3 according to the first embodiment is prepared. The solvent can be selected according to the types and solubility of the polymers and curable resin precursors contained in the anti-glare layer 3 described above. The solvent only needs to be able to uniformly dissolve at least the solid content (a plurality of types of polymers, curable resin precursors, reaction initiators, and other additives).

[0068] Examples of the solvent include ketones (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (such as dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (such as hexane, etc.), alicyclic hydrocarbons (such as cyclohexane, etc.), aromatic hydrocarbons (such as toluene, xylene, etc.), halogenated carbons (such as dichloromethane, dichloroethane, etc.), esters (such as methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (such as ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (such as methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (such as dimethyl sulfoxide, etc.), and amides (such as dimethylformamide, dimethylacetamide, etc.). Further, the solvent may be a mixed solvent.

[0069] As the resin composition, a thermoplastic resin, a photocurable compound, a photopolymerization initiator, and a composition containing a thermoplastic resin and a photocurable compound are desirable. Or as the resin composition, a composition containing a plurality of types of polymers that are mutually incompatible, a photocurable compound, and a photopolymerization initiator is desirable.

[0070] The concentration of the solutes (polymers, curable resin precursors, reaction initiators, and other additives) in the mixture can be adjusted within a range where phase separation of the plurality of resin components occurs and within a range that does not impair the castability or coatability, etc.

[0071] [Forming step] In the forming step, the solution prepared in the preparation step is cast or coated onto the surface of a support (here, as an example, the base film 2). Examples of the casting method or coating method of the solution include conventional methods such as spraying, 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, and silk screen coater.

[0072] From the solution cast or coated on the surface of the support, the solvent is removed by evaporation through drying. Along with the concentration of the solution during this evaporation process, phase separation due to spinodal decomposition from the liquid phase of the plurality of resin components occurs, forming a phase separation structure with a relatively regular interphase distance (pitch or mesh diameter). The co-continuous phase structure of the elongated convex portions can be produced by setting drying conditions and formulations such that the melt fluidity of the resin components after solvent evaporation is somewhat high.

[0073] From the viewpoint of facilitating the formation of elongated convex portions on the surface of the antiglare layer 3 according to the first embodiment, it is preferable to perform the evaporation of the solvent by heat drying. Caution is required because if the drying temperature is too low or the drying time is too short, the amount of heat applied to the resin components becomes insufficient, the melt fluidity of the resin components decreases, and it may become difficult to form the elongated convex portions.

[0074] On the one hand, if the drying temperature is too high or the drying time is too long, although the slender convex portions once formed may flow and their height may decrease, their structure is maintained. Therefore, in order to set the glare value, specular gloss, transmitted image sharpness, and haze value of the antiglare layer 3 to values within the range that satisfies the above conditions, in addition to adjusting the combination of the phase separation materials, it can be realized by adjusting the drying temperature and drying time to adjust the height of the slender convex portions and the like. Also, in the forming process, a co-continuous phase structure in which the phase separation structures are connected can be produced by increasing the evaporation temperature of the solvent or using a component with low viscosity for the resin component.

[0075] As the co-continuous phase structure is formed and coarsens with the progress of phase separation by spinodal decomposition from the liquid phases of a plurality of resin components, the continuous phase becomes discontinuous, and a droplet phase structure (an island structure of independent phases such as spherical, true spherical, disk-shaped, or ellipsoidal) is formed. Here, depending on the degree of phase separation, an intermediate structure between the co-continuous phase structure and the droplet phase structure (the phase structure in the process of transitioning from the co-continuous phase to the droplet phase) can also be formed. After solvent removal, a layer having fine irregularities on the surface is formed.

[0076] [Curing Process] In the curing process, the curable resin precursor contained in the solution is cured to fix the phase separation structure formed in the forming process and form the antiglare layer 3 according to the first embodiment. The curing of the curable resin precursor can be performed by heating, irradiation with active energy rays, or a combination of these methods according to the type of the curable resin precursor. The active energy rays to be irradiated are selected according to the type of photocuring component or the like.

[0077] The irradiation with active energy rays may be performed in an inert gas atmosphere as necessary. When the active energy rays are ultraviolet rays, as the light source, an extreme ultraviolet lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp, and a laser light source (light sources such as a helium-cadmium laser and an excimer laser) can be used.

[0078] In addition, when forming the adhesive layer 4, after preparing a solution containing an adhesive component, it can be formed by applying and drying the solution on the other surface of the base film 2 by a conventional method, for example, the casting method or the coating method described above in the forming process.

[0079] By going through the above steps, the antiglare film 1 according to the first embodiment is manufactured. When using a support with peelability 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. Further, when using a non-peelable support (preferably a transparent support such as the base film 2) 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.

[0080] Here, as a method for suppressing the glare of the display 16a, for example, reducing the unevenness on the surface of the antiglare layer can be considered, but there is a risk that the antiglare property of the antiglare film may decrease. However, by not only reducing the unevenness of the antiglare layer but also increasing the slope of the unevenness of the antiglare layer to steepen the unevenness and increasing the number of unevenness, it is possible to improve the antiglare property while suppressing the glare of the display.

[0081] In the first embodiment, such unevenness can be formed in the antiglare layer by spinodal decomposition described above, but such unevenness can also be formed in the antiglare layer by other methods. For example, even when using a plurality of fine particles to form the unevenness on the surface of the antiglare layer as in the second embodiment, by selecting materials such that the repulsive interaction between the fine particles and other resins and solvents becomes strong during the formation of the antiglare layer, appropriate aggregation of the fine particles can be caused, and a steep and high number density unevenness distribution structure can be formed in the antiglare layer. Therefore, below, the antiglare layers of other embodiments will be described centering on the differences from the first embodiment.

[0082] Hereinafter, the antiglare layer 3 according to other embodiments (second embodiment, embodiment 3) will be described.

[0083] (Second Embodiment) The antiglare layer 3 according to the second embodiment includes a matrix resin and a plurality of fine particles dispersed in the matrix resin. The plurality of fine particles are formed in a true spherical shape, but are not limited thereto, and may be formed in a substantially spherical shape or an ellipsoidal shape. Further, the fine particles are formed solid, but may be formed hollow. When the fine particles are formed hollow, the hollow portion of the fine particles may be filled with air or other gas. In the antiglare layer 3 according to the second embodiment, each fine particle may be dispersed as a primary particle, or a plurality of secondary particles formed by aggregating a plurality of fine particles may be dispersed.

[0084] The refractive index difference between the matrix resin and the fine particles is set to a value in the range of 0 or more and 0.2 or less. This refractive index difference is more preferably a value in the range of 0 or more and 0.15 or less, and even more preferably a value in the range of 0 or more and 0.07 or less.

[0085] The fine particles are set to have an average particle diameter in the range of 0.5 μm or more and 5.0 μm or less. The average particle diameter of the fine particles is more preferably in the range of 0.5 μm or more and 4.0 μm or less, and even more preferably in the range of 1.0 μm or more and 3.0 μm or less.

[0086] Also, it is desirable that the variation in the particle diameter of the fine particles is small. For example, in the particle diameter distribution of the fine particles contained in the antiglare layer 3, it is desirable that the average particle diameter of 50% by weight or more of the fine particles contained in the antiglare layer 3 is within a variation of 1.0 μm.

[0087] In this way, the fine particles with a relatively uniform particle diameter and an average particle diameter set within the above range form uniform and appropriate irregularities on the surface of the antiglare layer 3. Thereby, it is possible to suppress the glare of the display 16a while ensuring the antiglare property.

[0088] In addition, the ratio of the weight of the matrix resin to the total weight of the plurality of fine particles in the antiglare layer 3 can be set as appropriate. In the second embodiment, the ratio G2 / G1 of the weight G1 of the matrix resin of the antiglare layer 3 to the total weight G2 of the plurality of fine particles contained in the antiglare layer 3 is set to a value in the range of 0.03 or more and 0.20 or less. The ratio G2 / G1 is preferably a value in the range of 0.03 or more and 0.17 or less, and more preferably a value in the range of 0.03 or more and 0.14 or less.

[0089] The fine particles dispersed in the matrix resin may be either inorganic or organic, but those having good transparency are preferred. Examples of the organic fine particles include plastic beads. Examples of the 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, and the like. The plastic beads preferably have a hydrophobic group on the surface. Examples of such plastic beads include styrene beads.

[0090] Examples of the matrix resin can include at least one of a photocurable resin cured by active energy rays, a solvent-drying type resin cured by drying a solvent added during coating, and a thermosetting resin.

[0091] Examples of the photocurable resin include those having acrylate-based functional groups, such as oligomers, prepolymers, and reactive diluents of (meth)acrylate of polyfunctional compounds 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, and polyhydric alcohols.

[0092] Specific examples thereof include monofunctional monomers such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene, N-vinylpyrrolidone, etc., and polyfunctional monomers, for example, polymethylolpropane tri(meth)acrylate, hexanediol di(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, neopentyl glycol di(meth)acrylate, etc.

[0093] When the photocurable resin is an ultraviolet curable resin, it is preferable to use a photoinitiator. Examples of the photoinitiator include acetophenones, benzophenones, Michler's benzoyl benzoate, α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthones. It is also preferable to use a photosensitizer mixed with the photocurable resin. Examples of the photosensitizer include n-butylamine, triethylamine, poly-n-butylphosphine, etc.

[0094] Examples of the solvent-drying type resin include known thermoplastic resins. Examples of such 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 rubbers or elastomers, etc. As the solvent-drying type resin, a resin that is soluble in an organic solvent and is particularly excellent in moldability, film-forming property, transparency, and weather resistance is desirable. Examples of such solvent-drying type resins include styrene resins, (meth)acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (such as cellulose esters).

[0095] Here, when the material of the base film 2 is a cellulose-based resin such as triacetyl cellulose (TAC), cellulose-based resins can be exemplified as the thermoplastic resin used for the solvent-drying type resin. Examples of this cellulose-based resin include cellulose derivatives such as nitrocellulose, acetyl cellulose, acetyl butyl cellulose, ethyl cellulose, methyl cellulose, cellulose acetate propionate, and ethyl hydroxyethyl cellulose. By using a cellulose-based resin as the solvent-drying type resin, the base film 2 and the antiglare layer 3 can be well adhered to each other, and excellent transparency can be obtained in the antiglare film 1.

[0096] In addition, examples of the solvent-drying type resin include other vinyl-based resins, acetal resins, acrylic resins, polystyrene resins, polyamide resins, and polycarbonate resins.

[0097] Examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, melamine-urea co-condensation resin, silicone resin, and polysiloxane resin. When using a thermosetting resin as the matrix resin, at least one of a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, and a viscosity modifier may be used in combination.

[0098] As an example, the manufacturing method of the antiglare film 1 according to the second embodiment includes a preparation step of preparing a solution that is a raw material of the antiglare layer 3 according to the second embodiment, a coating step of coating the solution prepared in the preparation step on the surface of a predetermined support (the base film 2 in the second embodiment), and a curing step of curing the resin in the coated solution.

[0099] [Preparation Step] In the preparation process, a solution containing a solvent, a resin composition and fine particles for forming the antiglare layer 3 according to the second embodiment is prepared. Examples of the solvent include at least one of alcohols (such as isopropyl alcohol, methanol, ethanol, etc.), ketones (such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, etc.), esters (such as methyl acetate, ethyl acetate, butyl acetate, etc.), halogenated hydrocarbons, and aromatic hydrocarbons (such as toluene, xylene, etc.). A known leveling agent may be further added to the solution. For example, by using a fluorine-based or silicone-based leveling agent, good scratch resistance can be imparted to the antiglare layer.

[0100] [Coating and Curing Process] In the coating process, the solution prepared in the preparation process is cast or coated on the surface of a support (here, as an example, the base film 2) in the same manner as in the first embodiment. The solvent is evaporated and removed by drying from the solution cast or coated on the surface of the support.

[0101] When the matrix resin is a photocurable resin, after the coating process, a curing process using, for example, ultraviolet rays or electron beams is performed. Examples of the ultraviolet light source include light sources of various mercury lamps, ultraviolet carbon arc lamps, black lights, and metal halide lamps. Also, as the wavelength range of the ultraviolet rays, for example, a wavelength range of 190 nm or more and 380 nm can be exemplified.

[0102] Examples of the electron beam source include known electron beam accelerators. Specifically, various electron beam accelerators such as Van de Graaff type, Cockcroft-Walton type, resonance transformer type, insulated core transformer type, linear type, dynamitron type, and high frequency type can be exemplified.

[0103] When the matrix resin contained in the solution cures, the positions of the fine particles in the matrix resin are fixed. As a result, a plurality of fine particles are dispersed in the matrix resin, and an antiglare layer having a structure with irregularities due to the fine particles formed on the surface is formed.

[0104] According to the antiglare film 1 according to 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 the glare of the display 16a while ensuring good antiglare properties.

[0105] (Third Embodiment) The antiglare layer 3 of the antiglare film 1 according to the third embodiment has a structure in which an uneven shape is formed on the surface opposite to the substrate film 2 side. The antiglare layer 3 according to the third embodiment is composed of a resin layer. This resin layer is, for example, made of the same material as the matrix resin included in the antiglare layer 3 according to the second embodiment.

[0106] The antiglare film 1 according to the third embodiment is, for example, manufactured by forming a coat layer made of a curable resin on the substrate film 2, shaping the surface of this coat layer into an uneven shape, and then curing the coat layer. FIG. 2 is a diagram showing the manufacturing method of the antiglare film 1 according to the third embodiment. In the example of FIG. 2, an ultraviolet curable resin is used as the curable resin.

[0107] As shown in FIG. 2, in this manufacturing method, the substrate film 2 is unwound from an unwinding roll (not shown) and conveyed in a predetermined direction. The downstream end portion in the conveyance direction of the substrate film 2 is inserted into the nip point N1 of a pair of rolls 21, 22.

[0108] On the peripheral surface of the roll 22, a precursor of an ultraviolet curable resin is adhered from the peripheral surface of the roll 23 pivotally supported adjacent to the roll 22. When the substrate film 2 passes through the nip point N1, this precursor of the ultraviolet curable resin is applied to one surface of the substrate film 2.

[0109] The layer of the precursor of the ultraviolet curable resin applied to the substrate film 2 (hereinafter referred to as the coat layer) is pressed together with the substrate film 2 at the nip point of the rolls 21, 24. The roll 24 is a roll-shaped mold (embossing roll) having fine unevenness formed on its peripheral surface, and transfers the uneven shape to the surface of the coat layer when passing through the nip point N2 of the rolls 21, 24.

[0110] The coating layer with the concavo-convex shape transferred to its surface by the roll 24 is cured by ultraviolet rays irradiated from the ultraviolet lamp 26 provided below the rolls 21 and 24. Thereby, the antiglare layer 3 of the antiglare film 1 according to the third embodiment is formed. The antiglare film 1 according to the third embodiment manufactured in this way is released from the roll 24 by a roll 25 pivotally supported adjacent to the roll 24 and conveyed in a predetermined direction.

[0111] Here, the concavo-convex portions on the surface of the roll 24 are formed by impacting blast particles of a predetermined particle size by the blasting method, and by adjusting the blast particle size, the concavo-convex shape formed on the coating layer of the antiglare film 1 can be adjusted.

[0112] As the base film 2 of the antiglare film 1 according to the third embodiment, a PET (polyethylene terephthalate) film, a TAC (triacetyl cellulose) film, a COP (cycloolefin polymer) film, an acrylic resin film, or a polycarbonate resin film can be preferably used.

[0113] Thus, the manufacturing method of the antiglare film 1 according to the third embodiment includes a step (a) of applying a curable resin precursor to the base film 2, a step (b) of producing a roll-shaped mold having a concavo-convex shape on its surface by impacting blast particles, a step (c) of transferring the concavo-convex shape to the surface of the curable resin precursor applied to the base film 2 using this roll-shaped mold, and a step (d) of curing the curable resin precursor having the concavo-convex shape transferred thereto to form an antiglare layer 3 having a concavo-convex shape on the surface.

[0114] 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 or more and 50 μm or less. The average particle size of the blast particles is more preferably a value in the range of 20 μm or more and 45 μm or less, and even more preferably a value in the range of 30 μm or more and 40 μm or less. Thereby, the antiglare layer 3 according to the third embodiment with a concavo-convex shape formed on its surface is obtained.

[0115] Note that the mold used in the third embodiment may be other than a roll-shaped mold. For example, it may be a plate-shaped mold (embossing plate). Further, after forming a coat layer (resin layer) on one surface of the base film 2 according to the third embodiment, the antiglare layer 3 according to the third embodiment may be formed by shaping the surface of this coat layer with a mold. Further, in the above example, the coat layer was cured after shaping the surface of the coat layer, but the shaping and curing of the coat layer may be performed in parallel.

[0116] Examples of the material of the mold include metal, plastic, and wood. A film may be provided on the contact surface of the mold with the coat layer in order to improve the durability (wear resistance) of the mold. Examples of the material of the blast particles include metal, silica, alumina, and glass. The blast particles can be impinged on the surface of the mold by the pressure of, for example, a gas or a liquid. Further, if the curable resin precursor is an electron beam curable type, an electron beam source such as an electron beam accelerator can be used instead of the ultraviolet lamp 26, and if it is a thermosetting type, a heating source such as a heater can be used instead of the ultraviolet lamp 26.

[0117] Note that the antiglare layer 3 of the antiglare film 1 according to each of the above-described embodiments may further have an upper layer disposed on the surface opposite to the base film 2 side. By providing this upper layer, it is possible to easily adjust the external haze of the antiglare layer 3 and to easily protect the antiglare film 1 from the outside.

[0118] 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 or more and 2.0 μm or less. The thickness of the upper layer is more preferably a value in the range of 50 nm or more and 1.0 μm or less, and even more preferably a value in the range of 70 nm or more and 0.5 μm or less.

[0119] Next, an evaluation apparatus and an evaluation method for quantitatively evaluating the glare of the antiglare film 1 according to each of the above-described embodiments will be described with reference to FIG. 3.

[0120] (Glare inspection machine) FIG. 3 is a diagram showing an example of the schematic configuration of the glare inspection machine 10 according to an embodiment of the present invention. The glare inspection machine 10 is a device that inspects the size of glare on the display 16a of the display device 16 on which the antiglare film 1 is mounted. The glare inspection machine 10 includes a housing 11, an imaging device 12, a holding unit (adjustment unit) 13, a mount 14 for the imaging device, a mount (adjustment unit) 15 for the display device, and an image processing device 17.

[0121] The housing 11 is for forming a dark room as an inspection space for glare evaluation, and has a hollow rectangular parallelepiped shape. Inside the housing 11, the imaging device 12, the holding unit 13, the mount 14 for the imaging device, the mount 15 for the display device, and the display device 16 to be the target of glare evaluation are accommodated. Note that the housing 11 is configured to prevent light from entering the inside of the housing 11 from the outside during imaging by the imaging device 12.

[0122] The imaging device 12 is an area camera having a lens 18 and an imaging element as an example, and images the image displayed on the display 16a. The imaging device 12 is held by the holding unit 13 so that the lens 18 and the display 16a face each other. The imaging device 12 is connected to the image processing device 17, and the image data imaged by the imaging device 12 is transmitted to the image processing device 17.

[0123] The holding unit 13 is a member having a rod shape extending in the vertical direction (the vertical direction in FIG. 3). The base end side of the holding unit 13 is fixed by the mount 14 for the imaging device, and the imaging device 12 is held on the tip end side. Then, the imaging device 12 can be moved in the vertical direction by the holding unit 13, and the relative distance between the display 16a and the lens 18 can be changed.

[0124] The display device 16 is placed on the upper surface of the display device stand 15 with the display 16a equipped with the antiglare film 1 facing the imaging device 12. The display device stand 15 supports the display device 16 such that the surface of the display 16a equipped with the antiglare film 1 faces the imaging device 12 and is horizontal, and can move the display device 16 in the vertical direction so as to change the relative distance between the display 16a and the lens 18.

[0125] In the glare inspection machine 10, by adjusting the relative distance between the imaging device 12 and the display 16a, the size of the image displayed on the display 16a captured by the imaging element of the imaging device 12 is adjusted. In other words, the pixel size of the image displayed on the display 16a captured per unit pixel (for example, 1 pixel) of the imaging element of the imaging device 12 is adjusted.

[0126] The image processing device 17 performs data processing on the image data captured by the imaging device 12. Specifically, the image processing device 17 obtains the value of the standard deviation of the luminance of the image displayed on the display 16a from the image data captured by the imaging device 12.

[0127] The image processing device 17 according to the present embodiment includes an input unit to which the image data captured by the imaging device 12 is input, an image processing unit that processes the input image data, and an output unit that outputs the result processed by the image processing unit to a display (not shown), a printing device, or the like.

[0128] In addition, as a method for adjusting the pixel size of the image displayed on the display 16a captured per unit pixel (for example, 1 pixel) of the imaging element, in addition to the method of changing the relative distance between the imaging device 12 and the display 16a, when the lens 18 provided in the imaging device 12 is a zoom lens, a method of changing the focal length of the imaging device 12 may also be used.

[0129] (Glare evaluation method) Next, a glare evaluation method using the glare inspection machine 10 will be described. In this glare evaluation method, for convenience of evaluation, the display 16a with the anti-glare film 1 attached to the surface is preliminarily caused to emit light uniformly in one color (for example, green) and displayed.

[0130] First, the size of the pixels of the display 16a with the anti-glare film 1 attached, which is imaged per unit pixel of the imaging element of the imaging device 12, is adjusted to a predetermined value (adjustment step).

[0131] In the adjustment step, according to the number of effective pixels of the imaging element of the imaging device 12, the relative distance between the imaging device 12 and the display 16a with the anti-glare film 1 attached is adjusted, and in the image data captured by the imaging device 12, the pixel bright lines of the image displayed on the display 16a with the anti-glare film 1 are absent, or even if there are bright lines, they are adjusted to such an extent that they do not affect the glare evaluation.

[0132] Note that the relative distance between the imaging device 12 and the display device 16 is preferably set in consideration of the actual usage mode of the display device 16 (for example, the relative distance between the user's eyes and the display 16a).

[0133] After performing the adjustment step, a measurement area for evaluating the glare of the display 16a with the anti-glare film 1 attached is set (setting step). In the setting step, the measurement area can be appropriately set according to, for example, the size of the display 16a.

[0134] After performing the adjustment step, the measurement area of the display 16a with the anti-glare film 1 attached is imaged by the imaging device 12 (imaging step). At this time, as an example, at least one of the exposure time of the imaging device 12 or the luminance of all the pixels of the display 16a is adjusted so that image data of a grayscale image with 8-bit gradation display and an average luminance of 170 gradations can be obtained. The image data captured in the imaging step is input to the image processing device 17.

[0135] After the imaging step, the image processing device 17 obtains the variation in luminance in the image of the measurement area of the display 16a with the antiglare film 1 attached from the image data (calculation step). In this calculation step, the variation in luminance can be quantified by obtaining the standard deviation of the luminance distribution. Here, the degree of glare of the display 16a with the antiglare film 1 attached increases as the variation in luminance of the display 16a with the antiglare film 1 attached becomes larger. Based on this, it can be quantitatively and objectively evaluated that the smaller the value of the standard deviation of the luminance distribution, the smaller the glare. Also, in the adjustment step, since the bright lines of the display 16a with the antiglare film 1 attached are adjusted to such an extent that they do not affect the evaluation of glare, luminance unevenness due to the bright lines can be suppressed, and accurate evaluation of glare can be performed.

[0136] By going through each of the above steps, the standard deviation of the luminance distribution of the display 16a in the state where the antiglare film 1 is attached to the surface can be obtained, and the glare can be evaluated based on the magnitude of the value.

[0137] (Examples and Comparative Examples) Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited by these examples.

[0138] Examples 1 to 5 are examples of the antiglare film 1 that is produced by the phase separation method and satisfies the conditions that the glare value is 10 or less, the specular glossiness (60-degree gloss) is 40% or less, and the transmission image sharpness (image sharpness) with an optical comb width of 0.5 mm is 40% or less. In other words, Examples 1 to 5 are examples of the antiglare film 1 that can satisfy the above-described conditions by the uneven shape formed on the surface of the antiglare film 1 by the phase separation method.

[0139] Example 6 is an example of the antiglare film 1 that is produced by the fine particle dispersion method and satisfies the conditions that the glare value is 10 or less, the specular glossiness (60-degree gloss) is 40% or less, and the transmission image sharpness (image sharpness) with an optical comb width of 0.5 mm is 40% or less.

[0140] On the one hand, Comparative Examples 1 to 3 are examples of the antiglare film 1 produced by the fine particle dispersion method, and Comparative Examples 4 and 5 are examples of the antiglare film 1 produced by the transfer formation method.

[0141] [Raw materials] The following raw materials were used for each of the examples and comparative examples. The refractive indices described below indicate the refractive indices after crosslinking (after curing) for those that are cured by crosslinking. Acrylic polymer having a polymerizable group: "Cyclomer P" manufactured by Daicel Ornex Co., Ltd. (refractive index 1.51) Cellulose acetate propionate: "CAP-482-20" manufactured by Eastman Chemical Company (refractive index 1.49), degree of acetylation = 2.5%, degree of propionylation = 46%, number average molecular weight in terms of polystyrene 75,000 Acrylic ultraviolet curable compound containing nanosilica (refractive index 1.46): "UVHC7800G" manufactured by Momentive Performance Materials Japan LLC (refractive index 1.52) Silicone acrylate: "EB1360" manufactured by Daicel Ornex Co., Ltd. (refractive index 1.52) Urethane acrylate: "UA-53H" manufactured by Shin-Nakamura Chemical Co., Ltd. (refractive index 1.52) Dipentaerythritol hexaacrylate: "DPHA" manufactured by Daicel Ornex Co., Ltd. (refractive index 1.52) Pentaerythritol tetraacrylate: "PETRA" manufactured by Daicel Ornex Co., Ltd. (refractive index 1.52) Acrylic ultraviolet curable compound containing silica (refractive index 1.46): "Z-757-4RL" manufactured by Aica Industries Co., Ltd. (refractive index 1.52) Fluorine-based compound having a polymerizable group: Fluorine-based antifouling additive "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd. Alkylphenone-based photopolymerization initiator (Photopolymerization initiator A): "IRGACURE 184" manufactured by BASF Alkylphenone-based photopolymerization initiator (Photopolymerization initiator B): "IRGACURE 907" manufactured by BASF Polyethylene terephthalate (PET) film: "Diafoil" manufactured by Mitsubishi Rayon Co., Ltd. Cellulose triacetate (TAC) film: "Fujitac TG60UL" manufactured by Fujifilm Corporation

[0142] [Example 1] 50 parts by mass of an acrylic polymer having a polymerizable group, 4 parts by mass of cellulose acetate propionate, 76 parts by mass of urethane acrylate, 1 part by mass of silicone acrylate, 1 part by mass of photoinitiator A, and 1 part by mass of photoinitiator B were dissolved in a solvent obtained by mixing 176 parts by mass of methyl ethyl ketone and 28 parts by mass of 1-butanol to prepare a solution.

[0143] This solution was cast onto a PET film (substrate film 2) using a wire bar (#18), and then left in an oven at 80°C for 1 minute to evaporate the solvent and form a coat layer with a thickness of about 9 μm. Then, the coat layer was irradiated with ultraviolet rays for about 5 seconds using an ultraviolet lamp such as a high-pressure mercury lamp to cure the coat layer by ultraviolet rays. Thereby, an antiglare layer 3 was formed, and the antiglare film of Example 1 was obtained.

[0144] [Example 2] 50 parts by mass of an acrylic polymer having a polymerizable group, 4 parts by mass of cellulose acetate propionate, 76 parts by mass of urethane acrylate, 1 part by mass of silicone acrylate, 1 part by mass of a fluorine-based compound having a polymerizable group, 1 part by mass of photoinitiator A, and 1 part by mass of photoinitiator B were dissolved in a solvent obtained by mixing 176 parts by mass of methyl ethyl ketone and 28 parts by mass of 1-butanol to prepare a solution.

[0145] 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 coat layer with a thickness of about 6 μm. Then, the coat layer was irradiated with ultraviolet rays for about 5 seconds using an ultraviolet lamp to cure the coat layer by ultraviolet rays. Thereby, an antiglare layer 3 was formed, and the antiglare film of Example 2 was obtained.

[0146] [Example 3] 12.5 parts by mass of an acrylic polymer having a polymerizable group, 4 parts by mass of cellulose acetate propionate, 150 parts by mass of a nano-silica-containing acrylic ultraviolet curable compound, 1 part by mass of silicone acrylate, 1 part by mass of photoinitiator A, and 1 part by mass of photoinitiator B were dissolved in a solvent obtained by mixing 81 parts by mass of methyl ethyl ketone, 24 parts by mass of 1-butanol, and 13 parts by mass of 1-methoxy-2-propanol to prepare a solution.

[0147] 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 with a thickness of about 9 μm. Then, the coating layer was irradiated with ultraviolet rays by an ultraviolet lamp for about 5 seconds for ultraviolet curing treatment, thereby forming an antiglare layer 3 and obtaining the antiglare film of Example 3.

[0148] [Example 4] 15.0 parts by mass of an acrylic polymer having a polymerizable group, 3 parts by mass of cellulose acetate propionate, 150 parts by mass of a nano-silica-containing acrylic ultraviolet curable compound, 1 part by mass of silicone acrylate, 1 part by mass of photoinitiator A, and 1 part by mass of photoinitiator B were dissolved in a solvent obtained by mixing 101 parts by mass of methyl ethyl ketone and 24 parts by mass of 1-butanol to prepare a solution.

[0149] 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 with a thickness of about 9 μm. Then, the coating layer was irradiated with ultraviolet rays by an ultraviolet lamp for about 5 seconds for ultraviolet curing treatment, thereby forming an antiglare layer 3 and obtaining the antiglare film of Example 4.

[0150] [Example 5] 50 parts by mass of an acrylic polymer having a coincidence group, 2.5 parts by mass of cellulose acetate propionate, 79.5 parts by mass of urethane acrylate, 1 part by mass of silicone acrylate, 1 part by mass of photoinitiator A, and 1 part by mass of photoinitiator B were dissolved in a solvent prepared by mixing 106 parts by mass of methyl ethyl ketone, 28 parts by mass of 1-butanol, and 70 parts by mass of cyclohexanone to prepare a solution.

[0151] 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 with a thickness of about 5 μm. Then, the coating layer was irradiated with ultraviolet rays by an ultraviolet lamp for about 5 seconds for ultraviolet curing treatment, thereby forming an antiglare layer 3, and an antiglare film of Example 4 was obtained.

[0152] [Example 6] A solution was prepared by mixing 50 parts by mass of a silica (refractive index 1.46)-containing acrylic ultraviolet curable compound (refractive index 1.52) and 50 parts by mass of 1-butanol.

[0153] 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 with a thickness of about 7 μm. Then, the coating layer was irradiated with ultraviolet rays by an ultraviolet lamp for about 5 seconds for ultraviolet curing treatment, thereby forming an antiglare layer 3, and an antiglare film of Example 6 was obtained. When the weight of the matrix resin (acrylic ultraviolet curable compound) was designated as G1 and the weight of the fine particles (silica) contained in the antiglare layer 3 was designated as G2, the ratio G2 / G1 of the two was 0.14.

[0154] [Comparative Example 1] Triacetyl cellulose (manufactured by Fuji Film Co., Ltd., thickness 80 μm) was prepared as a transparent substrate.

[0155] As the transparent resin, pentaerythritol triacrylate (PETA; manufactured by Daicel Ornex Co., refractive index 1.51) was used. As the light-transmitting particles, 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 respectively contained in amounts of 10.0 parts by mass and 16.5 parts by mass with respect to 100 parts by mass of the transparent resin. To this, a mixed solvent of toluene (boiling point 110 °C) and cyclohexanone (boiling point 156 °C) (mass ratio 7:3) was blended in an amount of 190 parts by mass with respect to 100 parts by mass of the transparent resin to obtain a resin composition.

[0156] This resin composition was applied to a transparent substrate, and dry air at 85 °C was passed through at a flow rate of 1 m / s and dried for 1 minute. The coating film thickness was 5 μm. Thereafter, ultraviolet rays were irradiated with an ultraviolet lamp (200 / cm under a nitrogen atmosphere 2 ) to subject the transparent resin to ultraviolet curing treatment, thereby forming an antiglare layer 3 and obtaining the antiglare film of Comparative Example 1.

[0157] [Comparative Example 2] Triacetyl cellulose (manufactured by Fuji Film Co., thickness 80 μm) was prepared as the transparent substrate.

[0158] As the transparent resin, a mixture of pentaerythritol triacrylate (PETA; manufactured by Daicel Ornex Co.), dipentaerythritol hexaacrylate (DPHA; manufactured by Daicel Ornex Co.), and polymethyl methacrylate (BR85; manufactured by Mitsubishi Rayon Co.) (mass ratio; PETA / DPHA / PMMA = 86 / 5 / 9) was used (refractive index 1.51). As the light-transmitting particles, 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) were respectively contained in amounts of 18.5 parts by mass and 3.5 parts by mass with respect to 100 parts by mass of the transparent resin. To this, a mixed solvent of toluene (boiling point 110 °C) and cyclohexanone (boiling point 156 °C) (mass ratio 7:3) was blended in an amount of 190 parts by mass with respect to 100 parts by mass of the transparent resin to obtain a resin composition.

[0159] This resin composition was applied to a transparent substrate, and dry air at 70 °C was circulated at a flow rate of 0.2 m / s and dried for 1 minute. The coating thickness was 3.5 μm. Thereafter, ultraviolet rays were irradiated with an ultraviolet lamp (200 mJ / cm 2 ) to subject the transparent resin to ultraviolet curing treatment, thereby forming the antiglare layer 3 and obtaining the antiglare film of Comparative Example 2.

[0160] [Comparative Example 3] Triacetyl cellulose (manufactured by Fuji Film Co., Ltd., thickness 80 μm) was prepared as the transparent substrate.

[0161] Pentaerythritol triacrylate (PE-3A; manufactured by Kyoeisha Chemical Co., Ltd., refractive index 1.53) was used as the transparent resin, and silica particles (SS50F; manufactured by Tosoh Silica Corporation, refractive index 1.47, average particle diameter 1.1 μm) and polystyrene particles (refractive index 1.59, average particle diameter 3.5 μm) were used as the light-transmitting particles. 26 parts by mass and 6.6 parts by mass were respectively contained with respect to 100 parts by mass of the transparent resin. To this, 5.3 parts by mass of a photopolymerization initiator A and 138 parts by mass of toluene (boiling point 110 °C) as a solvent were blended to obtain a resin composition.

[0162] This resin composition was applied to a transparent substrate, and dry air at 90 °C was circulated at a flow rate of 0.2 m / s and dried for 1 minute. The coating thickness was 5 μm. Thereafter, ultraviolet rays were irradiated with an ultraviolet lamp (200 mJ / cm 2 ) to subject the transparent resin to ultraviolet curing treatment, thereby forming the antiglare layer 3 and obtaining the antiglare film of Comparative Example 3.

[0163] [Comparative Examples 4 and 5] The antiglare films of Comparative Examples 4 and 5 were produced by forming a coating layer made of an ultraviolet-curable resin on which irregularities were transferred on the surface using a mold on a base film. Since the manufacturing process of the antiglare film by the transfer molding method has already been described above, a detailed description thereof will be omitted.

[0164] That is, the manufacturing methods of the antiglare films of Comparative Examples 4 and 5 include step (a) of applying an ultraviolet curable resin precursor to a base film, step (b) of producing a roll-shaped mold having an uneven shape on the surface by impinging blast particles, step (c) of transferring the uneven shape to the surface of the ultraviolet curable resin precursor applied to the base film using this roll-shaped mold, and step (d) of irradiating the ultraviolet curable resin precursor with the transferred uneven shape with ultraviolet rays to cure it and form a coat layer having an uneven shape on the surface.

[0165] Here, in step (b), a roll-shaped mold was produced by changing the value of the blast particle diameter in the range of 10 μm or more and 40 μm or less, and two types of films (Comparative Examples 4 and 5) having different haze (Hz) values were produced by the above manufacturing method.

[0166] In Comparative Examples 4 and 5, a TAC (triacetyl cellulose) film can be preferably used as the base film.

[0167] In addition, each of the antiglare films of Examples 1 to 6 and Comparative Examples 1 to 5 was evaluated by measuring the following items.

[0168] [Haze and total light transmittance] Measurement was performed in accordance with JIS K7136 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH-5000W). The haze was measured with the surface having the uneven structure arranged on the light receiver side.

[0169] [Transmission image sharpness] Measurement was performed in accordance with JIS K7105 using an image measuring instrument (manufactured by Suga Test Instruments Co., Ltd., ICM-1T), with the antiglare film installed so that the film formation 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.

[0170] [60-degree gloss] Measurement was performed at an angle of 60° in accordance with JlS K7105 using a gloss meter (manufactured by Horiba, Ltd., IG-320).

[0171] [Standard deviation (glitter value) of the luminance distribution of the display] As the display device 16, a smartphone ("Galaxy S4" manufactured by Samsung Electronics Co., Ltd.) was used, and an antiglare film for each sample was attached to the surface of the display 16a with optical adhesive. The resolution of the display 16a of this smartphone is 441 ppi. Then, using a glitter inspection machine 10 manufactured by Komatsu NTC, Ltd., the standard deviation (glitter value) of the luminance distribution of the display 16a was measured through the antiglare film for each sample. At the time of this measurement, the exposure time of the imaging device 12 or at least either the luminance of all pixels of the display 16a was adjusted so that image data of a grayscale image with 8-bit gradation display and an average luminance of 170 gradations could be obtained.

[0172] Here, the measurement results for each of the above-described items are shown in Table 1.

[0173]

Table 1

[0174] As shown in Table 1, by the phase separation method based on the raw materials and production conditions of Examples 1 to 5 and the fine particle dispersion method based on the raw materials and production conditions of Example 6, an antiglare film satisfying the above-described conditions (glitter value of 10 or less, specular glossiness of 40% or less, transmitted image sharpness of 40% or less) could be obtained.

[0175] That is, it was found that by setting the type of phase separation material to be combined, or the heating temperature of the composition in the drying process, the air volume of the drying air blown onto the composition, or the linear velocity as in Examples 1 to 5, an uneven shape that satisfies the above conditions can be formed on the surface of the antiglare film 1.

[0176] Also, the refractive index difference between the fine particles and the matrix resin is set to a value in the range of 0 or more and 0.07 or less, and the ratio G2 / G1 of the weight G1 of the matrix resin to the total weight G2 of the plurality of fine particles contained in the antiglare layer is selected to be 0.03 or more and 0.20. By selecting the fine particles to be dispersed in the matrix resin and producing them under the production conditions shown in Example 6, it was found that the antiglare film 1 satisfying the above conditions could be formed. That is, in the fine particle dispersion method of Example 6, by selecting a material such that the repulsive interaction between the fine particles and other resins and solvents becomes strong when forming the antiglare layer 3, appropriate aggregation of the fine particles is caused, and it is considered that a distribution structure of unevenness with a steep and high number density could be formed in the antiglare layer 3.

[0177] On the other hand, in the fine particle dispersion methods based on the raw materials and production conditions of Comparative Examples 1 to 3, an antiglare film satisfying the above-described conditions could not be produced. That is, in Comparative Examples 1 and 2, the refractive index difference between the fine particles and the matrix resin is greater than 0.07. In Comparative Example 3, the ratio G2 / G1 of the weight G1 of the matrix resin to the total weight G2 of the plurality of fine particles contained in the antiglare layer is outside the range of 0.03 or more and 0.20 or less.

[0178] Also, in the transfer molding methods based on the raw materials and production conditions of Comparative Examples 4 and 5, for example, an uneven shape statistically controlled like the phase separation method of Examples 1 to 3 could not be formed on the antiglare film, and an antiglare film satisfying the above-described conditions could not be produced.

[0179] The present invention is not limited to the above-described embodiments, and the configuration or method can be changed, added, or deleted without departing from the spirit of the present invention. For example, the fine particles of the second embodiment may be dispersed in the matrix resin of the antiglare layer 3 of the first embodiment or the third embodiment.

Explanation of Reference Numerals

[0180] 1 Antiglare film 3 Antiglare layer 16a Display

Claims

1. An antiglare film attached to the surface of a display, comprising an antiglare layer containing nanosilica, having a transmission image sharpness of 0.5 mm optical comb width of 40% or less, and a haze value in the range of 31.4% or more and 79.5% or less, and a base film disposed overlapping the antiglare layer, wherein the antiglare layer has the arrangement of organic fine particles in the antiglare layer eliminated, and the arrangement of the phase separation structure formed by the phase separation of a plurality of resin components in the antiglare layer, including a co-continuous phase structure, a droplet phase structure, a network structure, an island structure, or an intermediate structure between the co-continuous phase structure and the droplet phase structure, is eliminated. An antiglare film.

2. The antiglare layer includes a matrix resin and a plurality of fine particles dispersed in the matrix resin, The antiglare film according to claim 1, wherein the refractive index difference between the fine particles and the matrix resin is in the range of 0 or more and 0.07 or less.

3. The antiglare film according to claim 2, wherein 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 is in the range of 0.03 or more and 0.20 or less.

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