Optical film and display device

Abstract

This optical film includes: a base material; and a functional layer that contains a resin component and a functional component that is an antimicrobial agent and / or an antiviral agent. The functional component is an organic material. The proportion of the functional component relative to the resin component in the functional layer is 40 mass% or less. A first condition is that the average hydroxyl value of the resin component is 100 mg KOH / g or more. A second condition is that the water vapor permeability per-unit thickness of the functional layer is 170 (g / m2·day) / μm or more. The optical film satisfies the first condition and / or the second condition.

Description

Optical film and display device

[0001] The present disclosure relates to an optical film and a display device including the optical film.

[0002] Optical films have the function of controlling light reflection, transmission, etc. For example, optical films are disposed on the surface of a display device to make the screen of the display device easier to view.

[0003] In addition to optical properties such as haze, optical films are required to have various properties such as hardness and scratch resistance depending on the application. Furthermore, due to recent increased awareness of hygiene, there is also an increasing demand for optical films with antibacterial and antiviral properties. Antibacterial and antiviral properties can be imparted to optical films by adding an antibacterial and antiviral agent to the resin that constitutes the optical film. Metal particles containing silver or a silver compound are widely used as antibacterial and antiviral agents (see, for example, Patent Document 1).

[0004] Patent No. 6720639

[0005] When an optical film contains metal-based particles as an antibacterial and antiviral agent, a high content of metal-based particles increases light scattering on the surface and inside of the optical film, which tends to increase haze. Therefore, in order to obtain desired optical properties in the optical film, the content of metal-based particles is limited. In particular, for optical films characterized by high transparency, such as those requiring a haze of 1% or less, it is difficult to achieve both antibacterial and antiviral properties and optical properties. Furthermore, restrictions on the use of silver-based antibacterial and antiviral agents are becoming stricter in Europe.

[0006] On the other hand, in addition to metal particles, organic materials such as quaternary ammonium salts are also available as compounds that can be used as antibacterial and antiviral agents. Because organic antibacterial and antiviral agents are not particulate, they are less likely to increase haze. However, while curable resins, which are the main components of optical films, are generally hydrophobic to improve the strength and hardness of the films, many organic antibacterial and antiviral agents are hydrophilic. Therefore, if an attempt is made to form a layer in which an organic antibacterial and antiviral agent is mixed with the curable resin as a constituent layer of an optical film, phase separation occurs during curing of the layer, resulting in bleed-out.

[0007] The following describes various embodiments of an optical film and a display device for solving the above problems. [Aspect 1] An optical film includes a substrate and a functional layer containing a functional component, which is at least one of an antibacterial agent and an antiviral agent, and a resin component, wherein the functional component is an organic material, the ratio of the functional component to the resin component contained in the functional layer is 40 mass % or less, the average hydroxyl value of the resin component is 100 mg KOH / g or more, and the water vapor transmission rate per unit film thickness of the functional layer is 170 (g / m ２ The optical film satisfies at least one of the first and second conditions, and the second condition is that the surface roughness is at least 1 / μm (day). According to the above configuration, at least one of antibacterial and antiviral properties can be obtained, and an increase in haze and the occurrence of bleed-out in the functional layer can be suppressed.

[0008] [Aspect 2] The optical film according to [Aspect 1], which satisfies the first condition and has an average hydroxyl value of 200 mgKOH / g or less, is characterized in that the functional layer is prevented from decreasing in mechanical properties such as strength.

[0009] [Aspect 3] The optical film according to [Aspect 1] or [Aspect 2], wherein the polymer structural units contained in the resin component include a first structural unit having no hydroxyl groups and a second structural unit having one or more hydroxyl groups, and the ratio of the second structural unit to all structural units in the resin component is 0.40 or more. This configuration advantageously suppresses the occurrence of bleed-out in the functional layer.

[0010] [Aspect 4] The optical film according to any one of [Aspects 1] to [Aspect 3], wherein the haze of the optical film is 3% or less. This configuration provides high transparency. Furthermore, since the functional component is organic, it is easy to achieve a haze of 3% or less.

[0011] [Aspect 5] The optical film according to any one of [Aspects 1] to [Aspect 4], wherein the optical film comprises a resin layer supported on the substrate, the functional layer includes the resin layer, and the resin layer includes fine particles for scattering light. According to the above configuration, an optical film having antiglare properties can be realized.

[0012] [Aspect 6] The optical film according to aspect 5, wherein the average particle diameter of the fine particles is 30% or more of the thickness of the resin layer. According to the above configuration, the effect of scattering light by the fine particles can be suitably obtained.

[0013] [Aspect 7] The optical film according to [Aspect 5] or [Aspect 6], wherein the content of the fine particles in the resin layer is 3.0% by mass or more and 20% by mass or less, whereby the effect of scattering light by the fine particles is preferably obtained and deterioration of the mechanical properties of the resin layer is suppressed.

[0014] [Aspect 8] The optical film according to any one of [Aspects 1] to [Aspect 7], wherein the surface of the optical film has a pencil hardness of 2H or more. According to the above configuration, good mechanical properties can be obtained.

[0015] [Aspect 9] The optical film according to any one of [Aspects 1] to [Aspect 3] and [Aspects 5] to [Aspect 7], wherein the haze of the optical film is 5% or more and 35% or less. According to the above configuration, good antiglare properties can be obtained.

[0016] [Aspect 10] The optical film according to any one of [Aspects 1] to [Aspect 3], [Aspects 5] to [Aspect 7], and [Aspect 9], wherein the optical film has a 1° reflection clarity of 90 or less and a 5° reflection clarity of 60 or more. According to the above configuration, good antiglare properties can be obtained.

[0017] [Aspect 11] An optical film described in any one of [Aspects 1] to [Aspect 10], wherein the optical film comprises a resin layer supported on the substrate, the functional layer includes the resin layer, and the thickness of the resin layer is 1.0 μm or more.

[0018] According to the above configuration, the uniformity of the thickness of the resin layer, the applicability of the coating liquid for forming the resin layer, the mechanical strength of the resin layer, and, when the resin layer is a functional layer, the antibacterial activity and antiviral activity are improved.

[0019] [Aspect 12] The optical film according to any one of [Aspects 1] to 11], wherein the optical film comprises a resin layer supported on the substrate, and a low-refractive index layer having a refractive index lower than that of the resin layer and covering the resin layer on the side opposite the substrate, the functional layer including at least the resin layer of the resin layer and the low-refractive index layer, and the low-refractive index layer has a thickness of 30 nm to 300 nm. This configuration facilitates light interference and also facilitates obtaining good scratch resistance and adhesion to the resin layer.

[0020] [Aspect 13] The optical film according to any one of [Aspects 1] to [Aspect 12], wherein the functional component is a silane coupling agent containing a quaternary ammonium salt in its molecular structure, and the quaternary ammonium salt contains a halide ion. According to the above configuration, the optical film is suitable as an organic functional component.

[0021] [Aspect 14] The optical film according to [Aspect 13], wherein the optical film has a first surface and a second surface opposite the first surface and belonging to the substrate, and wherein elemental analysis of the first surface by X-ray photoelectron spectroscopy reveals that the elemental concentration of N is 0.80 atm% or more and 4.00 atm% or less, the elemental concentration of Si is 0.75 atm% or more and 4.50 atm% or less, and the elemental concentration of halogen elements is 0.35 atm% or more and 2.90 atm% or less. This configuration provides both good antibacterial and antiviral properties while suppressing bleed-out in the functional layer.

[0022] [Aspect 15] The optical film according to [Aspect 13], wherein the optical film has a first surface and a second surface opposite the first surface and belonging to the substrate, and wherein elemental analysis of the first surface by energy dispersive X-ray spectroscopy reveals that the elemental concentration of Si is 0.20 atm% or more and 1.30 atm% or less and the elemental concentration of halogen elements is 0.19 atm% or more and 1.40 atm% or less. This configuration provides both good antibacterial and antiviral properties while suppressing bleed-out in the functional layer.

[0023] [Aspect 16] The optical film has a first surface and a second surface opposite to the first surface and included in the substrate, and the amount of halogen elements eluted from the first surface as measured by ion chromatography is 4.0 nmol / cm ２ 55.0 nmol / cm or more ２ An optical film according to [Aspect 13], which is as follows: According to the above configuration, both antibacterial and antiviral properties are obtained favorably, while bleeding out in the functional layer is suppressed.

[0024] [Aspect 17] A display device comprising the optical film according to any one of [Aspects 1] to [Aspect 16], wherein the optical film is positioned on a display surface on which an image is displayed.

[0025] According to the above configuration, good optical and mechanical properties can be obtained in addition to antibacterial and antiviral properties near the surface of the display device.

[0026] According to the present disclosure, an optical film can be provided with at least one of antibacterial and antiviral properties, and an increase in haze and the occurrence of bleed-out can be suppressed.

[0027] Fig. 1 is a diagram showing a cross-sectional structure of a first example of an optical film according to an embodiment, Fig. 2 is a diagram showing a cross-sectional structure of a second example of an optical film according to an embodiment, and Fig. 3 is a diagram showing a configuration of a display device according to an embodiment.

[0028] An embodiment of an optical film and a display device will be described with reference to the drawings. [Layer Structure of Optical Film: First Example] FIG. 1 shows a first example of the layer structure of an optical film 10. An optical film 10A, which is the optical film 10 of the first example, includes a substrate 20 and a resin layer 21. The resin layer 21 is supported by the substrate 20. In the first example, the resin layer 21 contains a resin component and a functional component having at least one of antibacterial and antiviral properties. The surface of the resin layer 21 opposite the surface that contacts the substrate 20 is the surface of the optical film 10A. The surface of the optical film 10A is an example of a first surface, and is an active surface that exhibits antibacterial and antiviral properties. The surface of the optical film 10A opposite the first surface is a second surface, which is a surface of the substrate 20. In the first example, the resin layer 21 corresponds to a functional layer containing the functional component.

[0029] The structure of each layer will be described in detail below. <Substrate> The material and thickness of the substrate 20 may be any material and thickness that allows the resin layer 21 to be formed on the substrate 20. The substrate 20 is, for example, a resin film that is transparent to light in the visible range. Examples of materials for the resin film include polyester, polypropylene, polystyrene, nylon, polycarbonate, polyacrylonitrile, polyimide, triacetyl cellulose, etc. From the viewpoint of easy handling of the substrate 20, the thickness of the substrate 20 is preferably 12 μm or more, and more preferably 20 μm or more. If the thickness of the substrate 20 is 12 μm or more, the strength and quality of the substrate 20 are likely to be good. The substrate 20 may be a single-layer structure or a multi-layer structure.

[0030] <Resin Layer> The functional component contained in the resin layer 21 is a hydrophilic organic material. The functional component is not particulate. The functional component may function as either an antibacterial agent or an antiviral agent, or may function as both an antibacterial agent and an antiviral agent, or may be a component whose function as either an antibacterial agent or an antiviral agent changes depending on conditions such as the amount added. In this embodiment, a functional component is defined as being hydrophilic if it can be uniformly dissolved or dispersed when 100 g of the functional component is added to 10 g of water.

[0031] Specific examples of the functional component include quaternary ammonium salts, triclosan, biguanide, chitosan, terpene, hinokitiol, etc. For example, the functional component may be a silane coupling agent whose molecular structure includes a quaternary ammonium salt as a functional group that reacts with organic materials.

[0032] The mass ratio of the functional component to the resin component of the resin layer 21 is 40 mass % or less, which prevents bleeding out of the functional component during the formation of the resin layer 21 due to an excessive amount of the functional component.

[0033] The mass ratio of the functional component to the resin components of the resin layer 21 is preferably 3 mass% or more, and more preferably 5 mass% or more, from the viewpoint of enhancing antibacterial and antiviral activity. The mass ratio of the functional component to the resin components of the resin layer 21 is preferably 30 mass% or less, and more preferably 20 mass% or less, from the viewpoint of enhancing dispersibility of the functional component. By using a non-particulate functional component, an increase in haze of the optical film 10A can be avoided even if the resin layer 21 contains the functional component.

[0034] The resin component contained in the resin layer 21 may be an ultraviolet-curable resin or a thermosetting resin. The ultraviolet-curable resin is a cured product of a photopolymerizable compound. Examples of the photopolymerizable compound are monofunctional, difunctional, or trifunctional or higher functional (meth)acrylate compounds and urethane (meth)acrylate compounds. Note that "(meth)acrylate" is a general term for acrylate and methacrylate. Examples of thermosetting resins are acrylic resin, urethane resin, epoxy resin, etc. The resin component contained in the resin layer 21 may be one type or two or more types.

[0035] The resin layer 21 satisfies at least one of the following first and second conditions: First condition: The average hydroxyl value Hv of the resin component contained in the resin layer 21 is 100 mgKOH / g or more.

[0036] Second condition: The water vapor permeability Wx per unit thickness of the resin layer 21 is 170 (g / m ２ · day) / μm or more.

[0037] The first and second conditions are each described in detail below. (First Condition) The first condition is that the average hydroxyl value Hv of the resin component contained in the resin layer 21 is 100 mgKOH / g or more. The average hydroxyl value Hv is an actual measured value determined in accordance with JIS K0070 using the resin layer 21 or a material thereof as a sample, or a calculated value determined from the known hydroxyl value of the material.

[0038] For example, when the resin component is a polymer produced from multiple types of monomers, the average hydroxyl value Hv can be determined by calculating the product of the hydroxyl value and the molar fraction of each monomer and then summing the products for all the monomers. The molar fraction of a monomer is the ratio of the amount of substance of that monomer to the total amount of monomers. Note that each of these monomers is either a monomer without a hydroxyl group or a monomer with a hydroxyl group that does not contribute to the polymerization reaction.

[0039] Furthermore, for example, when the resin component contains multiple polymers and the hydroxyl value of each polymer is known, the average hydroxyl value Hv can be determined by calculating the product of the hydroxyl value of each polymer and the molar fraction, and then calculating the sum of these products for all polymers. The molar fraction of a polymer is the ratio of the amount of substance of that polymer to the total amount of polymers, and for each polymer, the value obtained by dividing the mass of the polymer by the number average molecular weight is treated as the amount of substance of the polymer.

[0040] When the average hydroxyl value Hv is 100 mgKOH / g or more, affinity between the resin component and the functional component is obtained, and therefore phase separation and bleeding out during the formation of the resin layer 21 are suppressed.

[0041] The average hydroxyl value Hv is preferably 200 mgKOH / g or less, so that the resin component does not contain too many hydrophilic groups, thereby preventing deterioration in mechanical properties such as strength and hardness of the resin layer 21.

[0042] (Second Condition) The second condition is that the water vapor permeability Wx per unit thickness of the resin layer 21 is 170 (g / m ２The water vapor permeability is determined in accordance with JIS Z0208 (Test method for moisture permeability of moisture-proof packaging materials (cup method)). The conditions for measuring the water vapor permeability are a temperature of 40°C, a humidity of 90% RH, and a test time of 24 hours.

[0043] For example, the water vapor permeability Wx per unit thickness of the resin layer 21 can be determined based on measurements of the water vapor permeability of the optical film 10A and the water vapor permeability of the substrate 20 alone. Specifically, when the water vapor permeability of the substrate 20 is WA and the water vapor permeability of the optical film 10A, i.e., the water vapor permeability of the laminate of the substrate 20 and the resin layer 21, is WB, the water vapor permeability WX of the resin layer 21 can be determined by the following formula (1): WX=WA×WB / (WA−WB) (Formula 1)

[0044] Furthermore, when the thickness of the resin layer 21 is t, the water vapor permeability Wx per unit thickness of the resin layer 21 can be calculated by the following formula (2): Wx=WX / t (Formula 2)

[0045] The larger the water vapor permeability Wx, the higher the affinity of the resin component of the resin layer 21 for water. ２ By ensuring that the thickness is equal to or greater than 1 / μm, the affinity between the resin component and the functional component is good, and therefore phase separation and bleeding out during the formation of the resin layer 21 are suppressed.

[0046] Furthermore, the larger the water vapor permeability Wx, the more easily the hydrophilic functional component will permeate the resin layer 21 and appear on the surface of the optical film 10A. Therefore, the functional component will be more likely to come into contact with bacteria or viruses and exhibit antibacterial or antiviral properties.

[0047] There is a correlation between the water vapor permeability Wx and the average hydroxyl value Hv, and the water vapor permeability Wx tends to increase as the average hydroxyl value Hv increases. By using a resin component with a high average hydroxyl value Hv, the water vapor permeability Wx can be increased.

[0048] On the other hand, the larger the water vapor permeability Wx, the fewer the cross-linked portions of the resin in the resin layer 21. Therefore, in order to prevent a decrease in the mechanical properties such as the strength and hardness of the resin layer 21, the water vapor permeability Wx should be set to 450 (g / m ２ ·day) / μm or less is preferable.

[0049] Other characteristics of the resin layer 21 will be further described. The following characteristics are applicable whether the resin layer 21 satisfies the first condition or the second condition. The resin component preferably includes a first structural unit that is a structural unit having no hydroxyl groups and a second structural unit that is a structural unit having one or more hydroxyl groups. One structural unit in the resin component means a structure derived from one molecule of a monomer. When the resin component includes multiple types of polymers, the structural units of the resin component include the structural units of each polymer. The resin component may include a polymer having the first structural unit and the second structural unit in one molecule, or may include a polymer whose molecule is composed only of the first structural unit and a polymer whose molecule has the second structural unit in one molecule.

[0050] When the resin component includes the first structural unit and the second structural unit, the mechanical properties of the resin layer 21 are more likely to be improved than when all of the structural units of the resin component are the second structural unit. The first structural unit has a structure derived from an acrylate monomer that does not have a hydroxyl group, such as pentaerythritol tetraacrylate or dipentaerythritol hexaacrylate. Examples of polymers consisting only of the first structural unit include acrylic resins and urethane resins produced from these monomers.

[0051] The second constitutional unit has a structure derived from an acrylate monomer having a hydroxyl group, such as pentaerythritol triacrylate, glycerin triacrylate, etc. Examples of polymers containing the second constitutional unit include acrylic resins produced from monomers containing these monomers, and other hydrophilic resins.

[0052] The structural ratio Rc, which is the ratio of the second structural unit to all structural units in the resin component, is preferably 0.40 or more. When the resin component contains multiple types of polymers, all structural units of the resin component mean all structural units in all polymers.

[0053] For example, when the resin component is a polymer produced from a first monomer having no hydroxyl groups and a second monomer having a hydroxyl group, the constituent ratio Rc is the molar fraction of the second monomer relative to the total monomer content. That is, when the amount of substance of the first monomer is A and the amount of substance of the second monomer is B, the constituent ratio Rc is expressed as B / (A+B). Note that each of these monomers is either a monomer having no hydroxyl groups or a monomer having a hydroxyl group that does not contribute to the polymerization reaction.

[0054] Furthermore, for example, when the resin component contains multiple polymers and the constituent ratio Rcp of each polymer is known, the constituent ratio Rc of the resin component can be found by calculating the product of the constituent ratio Rcp of each polymer and the molar fraction, and then calculating the sum of these products for all polymers. The molar fraction of a polymer is the ratio of the amount of substance of that polymer to the total amount of polymers, and for each polymer, the value obtained by dividing the mass of the polymer by the number average molecular weight is treated as the amount of substance of the polymer.

[0055] By setting the structural ratio Rc to 0.40 or more, the proportion of the second structural unit is sufficiently obtained, thereby favorably obtaining affinity between the resin component and the functional component. On the other hand, the structural ratio Rc is preferably set to 0.85 or less. This allows the proportion of the first structural unit to be sufficiently obtained, thereby suppressing deterioration of the mechanical properties of the resin layer 21.

[0056] The resin layer 21 may contain fine particles for adjusting the light scattering properties of the optical film 10A. The inclusion of fine particles makes it possible to adjust the surface roughness of the optical film 10A, thereby controlling the light scattering properties on the surface of the optical film 10A. If the surface of the optical film 10A has appropriate light scattering properties, it is possible to increase the diffuse reflection component of the light reflected on the surface of the optical film 10A and suppress the specular reflection component, thereby suppressing the reflection of the surroundings on the optical film 10A.

[0057] Furthermore, the inclusion of fine particles also makes it possible to control the light scattering properties inside the resin layer 21. By controlling the light scattering properties on the surface of the optical film 10A and inside the resin layer 21, it is possible to control the haze of the optical film 10A, thereby adjusting the transparency of the optical film 10A. In this embodiment, as described above, the functional component is an organic material that is not particulate, and therefore the haze of the optical film 10A can be controlled without being affected by the content of the functional component.

[0058] The fine particles are organic or inorganic fine particles. The resin layer 21 may contain one type of fine particles, or two or more types that differ from each other in at least one of material and average particle diameter. The average particle diameter of the fine particles is the volume-based median diameter (D50). The average particle diameter of the fine particles is preferably 30% or more of the thickness of the resin layer 21, and more preferably 50% to 80% of the thickness of the resin layer 21. The thickness of the resin layer 21 is the film thickness of the portion of the resin layer 21 that does not contain fine particles in the thickness direction. If the average particle diameter of the fine particles is within the above range, the light scattering effect of the fine particles can be suitably obtained.

[0059] The content of the fine particles in the resin layer 21 is preferably 3.0% by mass or more and 20% by mass or less. If the content of the fine particles is 3.0% by mass or more, the light scattering effect of the fine particles can be suitably obtained. If the content of the fine particles is 20% by mass or less, the resin component is not too small, and therefore deterioration of the mechanical properties of the resin layer 21 is suppressed.

[0060] The organic fine particles are resin particles made of a light-transmitting resin material such as acrylic resin, polystyrene resin, styrene-(meth)acrylic acid ester copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, or polyethylene fluoride resin.

[0061] Inorganic fine particles can be used as a material for controlling the sedimentation or aggregation of organic fine particles. Examples of inorganic fine particles include silica fine particles, metal oxide fine particles, and mineral fine particles. Examples of silica fine particles include colloidal silica and silica fine particles surface-modified with reactive functional groups such as (meth)acryloyl groups. Examples of metal oxides constituting metal oxide fine particles include aluminum oxide, zinc oxide, tin oxide, antimony oxide, indium oxide, titanium dioxide, and zirconium dioxide. Examples of minerals constituting mineral fine particles include mica, synthetic mica, vermiculite, montmorillonite, iron-montmorillonite, bentonite, beidellite, saponite, hectorite, stevensite, nontronite, magadiite, ilealite, kanemite, layered titanic acid, smectite, and synthetic smectite.

[0062] The resin layer 21 may contain various additives. Examples of the additives include an ultraviolet absorber, an antistatic agent, a leveling agent, a thickener, etc. The inclusion of additives can enable the resin layer 21 to exhibit ultraviolet absorption functions, antistatic functions, etc., and improve coatability and quality.

[0063] The thickness of the resin layer 21 is preferably 0.5 μm or more, and more preferably 1 μm or more, from the viewpoints of improving the uniformity of the thickness of the resin layer 21, the applicability of the coating liquid for forming the resin layer 21, the mechanical strength, and the antibacterial and antiviral activities of the resin layer 21. The thickness of the resin layer 21 is preferably 10 μm or less, and more preferably 5 μm or less, from the viewpoints of improving the adhesion of the resin layer 21 to the substrate 20 and reducing the load required for curing the resin layer 21.

[0064] The thickness of the resin layer 21 is the film thickness of the portion of the resin layer 21 that does not contain fine particles in the thickness direction. The thickness of the optical film 10 and each layer that constitutes the optical film 10 is the average value of sample thickness values ​​in the cross section of the object to be measured. The sample thickness value is a measurement value that is within 50% of the average value of thickness measurements taken at 10 points spaced 1 mm or more apart in the cross section of the object to be measured.

[0065] The resin layer 21 is formed by applying a resin layer coating liquid, which is a coating liquid for forming the resin layer 21, to the upper surface of the substrate 20 and curing the film thus formed. The resin layer coating liquid contains compounds for forming the resin component of the resin layer 21, functional components, polymerization initiators, and other auxiliary agents as needed. When forming a resin layer 21 containing fine particles, the resin layer coating liquid further contains fine particles.

[0066] The resin layer coating liquid can be applied by any known method such as bar coating, spin coating, offset coating, gravure coating, roll coating, die coating, etc. The method for curing the film after coating may be any method appropriate for the curing type of the resin component, and ultraviolet irradiation or heat drying is used.

[0067] 2 shows a second example of the layer structure of the optical film 10. An optical film 10B, which is the optical film 10 of the second example, includes a low refractive index layer 22 in addition to a substrate 20 and a resin layer 21. The low refractive index layer 22 has a refractive index lower than that of the resin layer 21 and has the function of suppressing surface reflection of the optical film 10B by utilizing light interference.

[0068] The low refractive index layer 22 is located on the resin layer 21. When the surface of the resin layer 21 has irregularities, the low refractive index layer 22 has a surface shape that follows the irregularities of the resin layer 21. In the second example, the surface of the low refractive index layer 22 opposite to the surface that contacts the resin layer 21 is the surface of the optical film 10B. The surface of the optical film 10B is an example of the first surface. As in the first example, the surface of the optical film 10B opposite to the first surface is the second surface, and the second surface is a surface of the substrate 20.

[0069] The low refractive index layer 22 contains an ultraviolet curable resin or a thermosetting resin. Examples of such resin components include the components exemplified as the resin components contained in the resin layer 21. The low refractive index layer 22 may also contain a refractive index adjuster for lowering the refractive index of the low refractive index layer 22. Examples of the refractive index adjuster include fluoride microparticles such as lithium fluoride, magnesium fluoride, sodium hexafluoroaluminate, and aluminum fluoride, as well as silica microparticles. Using silica microparticles having voids inside, such as porous silica microparticles or hollow silica microparticles, is effective in lowering the refractive index of the low refractive index layer 22.

[0070] The low refractive index layer 22 may contain various additives. Examples of additives include an ultraviolet absorber, an antistatic agent, a leveling agent, a thickener, etc. The inclusion of additives can enable the low refractive index layer 22 to exhibit ultraviolet absorption functions, antistatic functions, etc., and improve coatability and quality.

[0071] The low refractive index layer 22 is thinner than the resin layer 21. The average thickness of the low refractive index layer 22 is preferably 30 nm or more and 300 nm or less. If the average thickness of the low refractive index layer 22 is 30 nm or more, light interference is likely to occur, and if the average thickness of the low refractive index layer 22 is 300 nm or less, scratch resistance and adhesion to the resin layer 21 are likely to be maintained favorably.

[0072] In the optical film 10B of the second example, at least one of the resin layer 21 and the low refractive index layer 22 contains a functional component. The layer containing the functional component corresponds to the functional layer. It is sufficient that the functional layer containing the functional component satisfies at least one of the first and second conditions described in the first example. It is also preferable that the resin component of the functional layer also satisfies the condition described in the first example with respect to the composition ratio Rc.

[0073] The functional component may be any of the components exemplified in Example 1. The mass ratio of the functional component to the resin component of the functional layer is 40 mass % or less. The mass ratio of the functional component to the total mass of the resin layer 21 and the low refractive index layer 22 is preferably 0.1 mass % or more and 50 mass % or less.

[0074] Because the resin layer 21 is thicker than the low-refractive-index layer 22, the degree of freedom in adjusting the content of the functional component can be increased by incorporating the functional component into the resin layer 21. On the other hand, when the low-refractive-index layer 22 incorporates the functional component, the functional component is distributed near the surface of the optical film 10B, making it easier to obtain high antibacterial and antiviral effects.

[0075] When the resin layer 21 contains a functional component, the functional component acts on bacteria and viruses by eluting from the surface of the optical film 10B through the low refractive index layer 22. Therefore, it is preferable that the low refractive index layer 22 also satisfies at least one of the first and second conditions, and it is also preferable that the resin component of the low refractive index layer 22 also satisfies the condition explained in the first example regarding the composition ratio Rc.

[0076] The low refractive index layer 22 is formed by applying a low refractive index layer coating liquid, which is a coating liquid for forming the low refractive index layer 22, to the upper surface of the resin layer 21 and curing the film thus formed. The low refractive index layer coating liquid contains compounds for forming the resin component of the low refractive index layer 22, auxiliary agents as needed such as a polymerization initiator, and further contains a refractive index adjuster and functional components depending on the configuration of the low refractive index layer 22.

[0077] The coating liquid for the low refractive index layer can be applied by known methods such as bar coating, spin coating, offset coating, gravure coating, roll coating, die coating, etc. The method for curing the film after coating may be any method appropriate for the curing type of the resin component, and ultraviolet irradiation or heat drying is used.

[0078] [Characteristics of Optical Film] The following describes the optical characteristics, mechanical characteristics, and elemental composition of the optical film 10. The following characteristics are common to the optical films of the first and second examples.

[0079] <Optical Properties> When the resin layer 21 does not contain fine particles for scattering light, the haze of the optical film 10 is preferably 3% or less. With this configuration, the optical film 10 can have high transparency, and the visibility through the optical film 10 can be improved.

[0080] When the resin layer 21 contains fine particles for scattering light, the haze of the optical film 10 is preferably 5% or more and 35% or less. This configuration suppresses reflection of the surroundings on the optical film 10, while also preventing excessive deterioration in visibility through the optical film 10. The above haze is a transmission haze and is measured in accordance with JIS K7136.

[0081] Anti-glare properties are obtained when the resin layer 21 contains fine particles for light scattering. Anti-glare properties can be evaluated using reflection clarity at 1° and 5°. Reflection clarity is a value obtained by subtracting reflection haze (%) from 100. Reflection haze is a parameter indicating the degree of diffusion of reflected light. It is determined by irradiating the surface of the optical film 10 on a blackboard through a slit from a light source position set at an incident angle of approximately 5.7° relative to the normal direction of the surface of the optical film 10, and measuring the intensity distribution of reflected light near the specular reflection direction at the light receiving position in the specular reflection direction. The reflection haze at an arbitrary angle θ centered on the specular reflection direction is the percentage of the average reflection intensity at angle +θ and angle −θ relative to the reflection intensity in the specular reflection direction, and the reflection clarity at angle θ is the value obtained by subtracting the reflection haze at angle θ from 100. The measurement conditions are as follows; conditions other than those listed below are measured in accordance with ASTM D5767. Slit width: 1 mm Objective lens: 16 mm Distance from the surface of the optical film to the light receiving position: 300 mm

[0082] When the resin layer 21 contains fine particles for light scattering, it is preferable that the reflection clarity of the optical film 10 is 90 or less when the angle θ is 1° and 60 or more when the angle θ is 5°. This suppresses the reflection component in the observation direction and provides an appropriate reflection component in the vicinity of the observation direction. Therefore, the image reflected on the surface of the optical film 10 is appropriately blurred, thereby providing good antiglare properties.

[0083] <Mechanical Properties> The pencil hardness of the surface of the optical film 10, i.e., the scratch hardness measured using a pencil method, is preferably 2H or more. If the pencil hardness is 2H or more, the surface of the optical film 10 is less susceptible to scratches. The pencil hardness is measured in accordance with JIS K5600-5-4.

[0084] <Elemental Composition> In the optical film 10, the functional components exert antibacterial and antiviral properties by coming into contact with bacteria and viruses. Therefore, the more the functional components are distributed near the surface of the optical film 10, the higher the antibacterial and antiviral properties that can be obtained. Therefore, by measuring the amount of elements contained in the functional components near the surface of the optical film 10, the antibacterial and antiviral properties of the optical film 10 can be easily evaluated without having to conduct long-term antibacterial or antiviral tests.

[0085] In the following, a preferred elemental composition relating to the vicinity of the surface of the optical film 10 will be described for the case where the functional component is a silane coupling agent containing a quaternary ammonium salt in its molecular structure. The quaternary ammonium salt contains a halide ion, such as a chloride ion.

[0086] In elemental analysis of the surface of the optical film 10 by X-ray photoelectron spectroscopy (XPS), it is preferable that the element concentration of N is 0.80 atm % or more and 4.00 atm % or less, the element concentration of Si is 0.75 atm % or more and 4.50 atm % or less, and the element concentration of halogen elements is 0.35 atm % or more and 2.90 atm % or less.

[0087] According to the above configuration, both antibacterial and antiviral properties are obtained favorably because the functional component is sufficiently distributed on the surface of the optical film 10. On the other hand, because the amount of the functional component is not too large, bleeding out in the functional layer is suppressed.

[0088] In elemental analysis of the surface of the optical film 10 by energy dispersive X-ray spectroscopy (EDX), it is preferable that the element concentration of Si is 0.20 atm % or more and 1.30 atm % or less, and the element concentration of halogen elements is 0.19 atm % or more and 1.40 atm % or less.

[0089] According to the above configuration, the functional component is sufficiently distributed on the surface of the optical film 10 and in its vicinity, thereby achieving both good antibacterial and antiviral properties. Meanwhile, the amount of functional component is not too large, which reduces bleed-out in the functional layer. EDX allows elemental analysis at deeper positions than XPS, making it possible to perform analysis that takes into account the functional component that elutes from near the surface of the optical film 10 and acts on bacteria and viruses.

[0090] The amount of halogen elements eluted from the surface of the optical film 10 measured by ion chromatography was 4.0 nmol / cm ２ 55.0 nmol / cm or more ２ The elution amount is the amount of halide ions eluted per unit area of ​​the surface of the optical film 10 when the surface of the optical film 10 is kept in close contact with pure water for 24 hours.

[0091] The amount of eluted halogen element indicates whether the quaternary ammonium ions constituting the functional components are likely to be released from the optical film 10, including the functional components distributed not only near the surface of the optical film 10 but also within the film, i.e., whether the functional components are likely to act on bacteria and viruses. If the amount of eluted halogen element is within the above range, both antibacterial and antiviral properties are favorably obtained. On the other hand, because the amount of functional component is not too high, bleeding out in the functional layer is suppressed.

[0092] The sample used to measure the amount of eluted halogen elements is obtained by the following steps (a) to (c): (a) A test piece is prepared by molding the optical film 10 into a square shape with one side measuring 4 cm or more, and 0.4 mL of pure water is dropped onto the surface of the test piece, which is the surface of the optical film 10. Then, a polyethylene cover film with one side measuring 4 cm is adhered to the surface of the test piece after the pure water has been dropped. This allows the area of ​​the test piece surface covered by the cover film to be uniformly wetted with pure water. Therefore, the area to be measured for elution of halogen elements is 16 cm ２ is.

[0093] (b) After the treatment in (a) above, the test piece is placed in a petri dish, and the petri dish is left in an environment of a temperature of 35±1°C and a humidity of 90% RH or more for 24 hours. (c) After the treatment in (b) above, the surface of the test piece is washed with 2.5 mL of pure water, and the pure water used for washing is recovered to provide a sample for measuring the amount of eluted halogen element.

[0094] The elemental composition of the functional components near the surface of the optical film 10 described above can be adjusted by the content ratio of the functional components in the functional layer, and whether or not the functional layer contains additives such as leveling agents and their content ratios.

[0095] 3, the display device 100 includes an optical film 10 and a main body 30 having an image display function. A display surface 30S, which is the surface of the main body 30, is a surface on which an image is displayed, and is the surface of a display panel such as a liquid crystal panel or an organic EL panel, or the surface of a touch panel laminated on the display panel. The optical film 10 is positioned on the display surface 30S, and the back surface of the optical film 10 is attached to the display surface 30S.

[0096] In particular, when the display surface 30S is the surface of a touch panel, the user frequently touches the display device 100, and therefore it is highly beneficial for the optical film 10 to have antibacterial and antiviral properties.

[0097] Specific examples of the display device 100 include smartphones, tablet terminals, personal computers, portable game consoles, music playback devices, televisions, monitors, electronic book viewing terminals, digital cameras, head-mounted displays, navigation devices, copiers, facsimiles, printers, multi-function printers, vending machines, automatic teller machines (ATMs), personal authentication devices, optical communication devices, etc.

[0098] [Examples] The above-mentioned optical film will be described using specific examples and comparative examples. (Example 1) The following materials were mixed to prepare a resin layer coating liquid for forming a resin layer. Note that the parts by mass of each material below indicate the relative mass ratio of each material. Photopolymerizable compound: a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry) 100 parts by mass Photopolymerization initiator: 1-hydroxycyclohexyl phenyl ketone (Omnirad 184, manufactured by IGM Resins B.V.) 5.0 parts by mass Functional component: a quaternary ammonium salt-based antibacterial and antiviral agent (silane coupling agent) (KBM-9418-40, manufactured by Shin-Etsu Chemical Co., Ltd.) 10.0 parts by mass (breakdown: active ingredient 4.0 parts by mass, solvent (methanol) 6.0 parts by mass) Additive: a leveling agent (GRANDIC PC4300, manufactured by DIC) 0.5 parts by mass Solvent: toluene 110 parts by mass

[0099] A 60 μm-thick triacetyl cellulose film (TJ40, manufactured by Fujifilm) was used as a substrate, and the resin layer coating liquid was applied to the surface of the substrate using a bar coater. The formed coating film was dried at 100° C. for 1 minute using a dryer, and then irradiated with ultraviolet light in a nitrogen atmosphere (oxygen concentration 500 ppm or less) to harden the coating film, thereby forming a resin layer. The coating film had a thickness of 5 μm, and ultraviolet light was applied using a high-pressure mercury UV device with an integrated exposure dose of 200 mJ / cm. ２ In this way, an optical film of Example 1 including a substrate and a resin layer was obtained.

[0100] Example 2 An optical film of Example 2 was obtained using the same materials and steps as in Example 1, except that the photopolymerizable compound was changed to the following: Photopolymerizable compounds: 70 parts by mass of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 30 parts by mass of a mixture of glycerin diacrylate and glycerin triacrylate (M-920, manufactured by Toagosei Co., Ltd.)

[0101] Example 3 An optical film of Example 3 was obtained using the same materials and steps as in Example 1, except that the photopolymerizable compound was changed to the following: Photopolymerizable compounds: 40 parts by mass of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 60 parts by mass of a mixture of glycerin diacrylate and glycerin triacrylate (M-920, manufactured by Toagosei Co., Ltd.)

[0102] Example 4 An optical film of Example 4 was obtained using the same materials and processes as in Example 1, except that the following materials were added to the resin layer coating solution: Organic fine particles (SSX-2035, manufactured by Techpolymer) 6.0 parts by mass

[0103] Example 5 An optical film of Example 5 was obtained using the same materials and steps as in Example 3, except that the following materials were added to the resin layer coating solution: Organic fine particles (SSX-2035, manufactured by Techpolymer) 6.0 parts by mass

[0104] Example 6 An optical film of Example 6 was obtained using the same materials and steps as in Example 1, except that the photopolymerizable compound was changed to the following: Photopolymerizable compound: 100 parts by mass of a mixture of glycerin diacrylate and glycerin triacrylate (M-920, manufactured by Toagosei Co., Ltd.)

[0105] (Example 7) The optical film of Example 7 was obtained using the same materials and processes as in Example 1, except that the amount of functional component added in the resin layer coating liquid was changed to 20.0 parts by mass and no leveling agent additive was added to the resin layer coating liquid.

[0106] Example 8 An optical film of Example 8 was obtained using the same materials and processes as in Example 1, except that the functional component was changed to the following and no leveling agent additive was added to the resin layer coating liquid. Functional component: 30.0 parts by mass of a quaternary ammonium salt-based antibacterial and antiviral agent (silane coupling agent) (POLON-V8, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0107] Example 9 An optical film of Example 9 was obtained using the same materials and steps as in Example 1, except that no additive, a leveling agent, was added to the resin layer coating liquid.

[0108] Example 10 An optical film of Example 10 was obtained using the same materials and processes as in Example 1, except that the functional component was changed to the following and no leveling agent additive was added to the resin layer coating liquid. Functional component: 10.0 parts by mass of a quaternary ammonium salt-based antibacterial and antiviral agent (silane coupling agent) (POLON-V8, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0109] (Comparative Example 1) An optical film of Comparative Example 1 was obtained using the same materials and steps as in Example 1, except that the photopolymerizable compound was changed to the following and no leveling agent additive was added to the resin layer coating liquid. Photopolymerizable compound: 100 parts by mass of dipentaerythritol polyacrylate (NK Ester A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0110] Comparative Example 2 An optical film of Comparative Example 2 was obtained using the same materials and steps as in Example 1, except that the photopolymerizable compound was changed to the following: Photopolymerizable compounds: 32 parts by mass of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 68 parts by mass of dipentaerythritol polyacrylate (NK Ester A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0111] Comparative Example 3 An optical film of Comparative Example 3 was obtained using the same materials and steps as in Comparative Example 2, except that the following materials were added to the resin layer coating solution: Organic fine particles (SSX-2035, manufactured by Techpolymer) 6.0 parts by mass

[0112] Comparative Example 4 An optical film of Comparative Example 4 was obtained using the same materials and processes as in Example 1, except that the functional component was changed as follows: Functional component: 5.0 parts by mass of silver-based antibacterial and antiviral agent (PTC-NT ANV Additive ST, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.)

[0113] Comparative Example 5 An optical film of Comparative Example 5 was obtained using the same materials and steps as in Example 1, except that the amount of the functional component added to the resin layer coating liquid was changed to 50.0 parts by mass.

[0114] (Evaluation Method) <Water Vapor Permeability> According to JIS Z0208 (Testing Method for Moisture Permeability of Moisture-Proof Packaging Materials (Cup Method)), the water vapor permeability of the optical film and the substrate of each Example and Comparative Example was measured under the conditions of temperature: 40°C, humidity: 90% RH, and test time: 24 hours. Then, using (Equation 1) and (Equation 2) described in the above embodiment, the water vapor permeability Wx per unit film thickness of the resin layer of each Example and Comparative Example was calculated.

[0115] <Pencil Hardness> For the optical films of each Example and Comparative Example, a hardness test was carried out in accordance with JIS K5600-5-4 using a pencil (uni, manufactured by Mitsubishi Pencil Co., Ltd.) and a Clemens scratch hardness tester (HA-301, manufactured by Tester Sangyo Co., Ltd.) under conditions of a load of 750 g and a scratching speed of 0.5 mm / sec, thereby measuring the pencil hardness of the optical film surface. In the measurement, the test was repeated while changing the pencil hardness, and the surface of the optical film was visually observed, and the maximum hardness at which no scratches were observed was taken as the measurement result.

[0116] <Haze> The haze of the optical films of each example and each comparative example was measured using a haze meter (NDH7000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7136.

[0117] <Bleeding Out> For each of the Examples and Comparative Examples, the surface of the optical film was rubbed with a nonwoven fabric (Bencott M-3II, manufactured by Asahi Kasei Corporation), and then the state of the surface was observed. The presence or absence of bleed out was evaluated as good (S) when there was no change in the surface appearance before and after rubbing, and as poor (F) when there was a change in the surface appearance, such as a change in haze or the occurrence of scratch marks, after rubbing.

[0118] <Anti-glare Properties> Anti-glare properties were evaluated by measuring the reflection clarity at 1° and 5° for the optical films of each Example and Comparative Example. Each reflection clarity was measured under the following conditions using a display measurement system (DM&S: SMS-1000) for an optical film whose back surface was attached to a blackboard with an optical adhesive. Note that the measurements were carried out under conditions other than those listed below in accordance with ASTM D5767. - Light source slit width: 1 mm - Objective lens: 16 mm - Distance between the surface of the optical film and the light-receiving camera: 300 mm

[0119] In the evaluation of antiglare properties, a case where the 1° reflection clarity was 90 or less and the 5° reflection clarity was 60 or more was rated as good "S", and a case where at least one of the 1° reflection clarity was greater than 90 and the 5° reflection clarity was less than 60 was rated as poor "F". Poor includes cases where the surrounding image is clearly reflected on the optical film and cases where the image reflected on the optical film is too blurred.

[0120] <XPS Analysis> For Examples 1, 7 to 10 and Comparative Example 5, elemental analysis by XPS was performed on the surface of the optical film using an X-ray photoelectron spectrometer (Quantum 2000, manufactured by ULVAC-PHI). The measurement conditions are as follows: X-ray source: monochromated Al-Kα rays X-ray output: 25 W 15 kV Photoelectron acceptance angle: 45°

[0121] <EDX Analysis> For Examples 1, 7 to 10 and Comparative Example 5, elemental analysis by EDX was carried out on the surfaces of the optical films using a scanning electron microscope-energy dispersive X-ray analyzer (SU-8020, manufactured by Hitachi High-Technologies Corporation).

[0122] <Ion Chromatography Analysis> For Examples 1, 7 to 10 and Comparative Example 5, an ion chromatograph analyzer (DX-500, manufactured by Dionex) was used to quantify chloride ions by ion chromatography in the eluate from the surface of the optical film. An anion exchange column (manufactured by Dionex, stationary phase: IonPac AS11-HC-4 μm) was used as the column, and a KOH solution was used as the release liquid. The eluate, i.e., the sample used to measure the amount of eluted chloride ions, was obtained by the steps (a) to (c) described in the above embodiment.

[0123] <Antibacterial Property> For the optical films of each Example and Comparative Example, antibacterial tests against Staphylococcus aureus and Escherichia coli were carried out in accordance with JIS Z 2801. As the unprocessed sample, a film from the corresponding Example or Comparative Example in which the functional component was omitted was used. In the evaluation of antibacterial property, an antibacterial activity value of 2.0 or more against both Staphylococcus aureus and Escherichia coli was rated as good "S", and an antibacterial activity value of less than 2.0 against at least one of Staphylococcus aureus and Escherichia coli was rated as poor "F".

[0124] <Antiviral Property> The optical films of each Example and Comparative Example were subjected to antiviral tests against influenza A virus and feline calicivirus in accordance with ISO 21702. As the unprocessed sample, a film from the corresponding Example or Comparative Example, in which the functional component was omitted, was used. In the evaluation of antiviral property, an antibacterial activity value of 2.0 or more against at least one of influenza A virus and feline calicivirus was rated as good "S", and an antibacterial activity value of less than 2.0 against both influenza A virus and feline calicivirus was rated as poor "F".

[0125] (Evaluation Results) Table 1 shows the average hydroxyl value Hv (mgKOH / g) of the resin component of the resin layer, the water vapor permeability Wx ((g / m ２The table shows the average hydroxyl value Hv (day) / μm), the composition ratio Rc, the type and amount of functional component, the presence or absence of light-scattering microparticles, and the results of each evaluation item. The average hydroxyl value Hv was calculated from the hydroxyl value of the monomers of the material. The composition ratio Rc was calculated from the mole fraction of the monomers of the material. The evaluation items were pencil hardness, haze (%), the presence or absence of bleed-out, antiglare properties, antibacterial properties, and antiviral properties. The antiglare properties were evaluated for Examples 4 and 5 and Comparative Example 3, which contain light-scattering microparticles for the purpose of exhibiting antiglare properties. Note that for Examples 7, 8, and 10 and Comparative Example 5, evaluation was not performed for some items.

[0126] The results of elemental analysis by XPS, EDX, and ion chromatography (IC) are shown in Table 2. Table 2 also shows the evaluation results of antibacterial and antiviral properties.

[0127]

[0128]

[0129] As shown in Table 1, in Examples 1 to 10, in which the resin component had an average hydroxyl value Hv of 100 mgKOH / g or more, bleed-out was suppressed even though the functional component was organic. On the other hand, in Comparative Examples 1 to 3, in which the resin component had an average hydroxyl value Hv of less than 100 mgKOH / g and the functional component was organic, bleed-out occurred. Also, in Comparative Example 5, in which the added amount of the functional component was 50 mass% of the resin component, bleed-out occurred.

[0130] Furthermore, in the case of a form not containing light-scattering fine particles, the haze was suppressed to less than 1% in Examples 1 to 3 and 6 to 10 in which the functional component was organic, whereas the haze exceeded 3% in Comparative Example 4 in which the functional component was silver particle-based.

[0131] From Table 1, it can be seen that there is a correlation between the water vapor permeability Wx per unit film thickness of the resin layer and the average hydroxyl value Hv of the resin component. In Examples 1 to 10, in which bleed-out was suppressed, the water vapor permeability Wx was 170 (g / m ２On the other hand, in Comparative Examples 1 to 3 in which bleed-out occurred, the water vapor permeability Wx was 170 (g / m ２ ・day) / μm or less.

[0132] From the above, it was confirmed that by using an organic functional component and a resin component with an average hydroxyl value Hv of 100 mgKOH / g or more, it is possible to obtain at least antibacterial properties while suppressing the deterioration of optical properties and the occurrence of bleed-out.

[0133] In addition, an organic functional component is used, and the water vapor permeability Wx of the resin layer is 170 (g / m ２ It has been confirmed that by having a surface roughness of at least 1 / μm (day), it is possible to obtain at least antibacterial properties while suppressing the deterioration of optical properties and the occurrence of bleed-out.

[0134] Furthermore, among the Examples, Example 6, in which the average hydroxyl value Hv of the resin component exceeds 200 mgKOH / g, exhibits a lower pencil hardness compared to the other Examples. Therefore, in order to suppress the deterioration of mechanical properties, it can be said that it is preferable that the average hydroxyl value Hv of the resin component is 200 mgKOH / g or less. Similarly, Example 6 shows that in order to suppress the deterioration of mechanical properties, it is preferable that the water vapor permeability Wx is 450 (g / m ２ It can be said that it is preferable that the average particle diameter is equal to or less than 1 / μm.

[0135] Furthermore, from the viewpoint of the composition ratio Rc, it was confirmed that if the composition ratio Rc is 0.40 or more, bleed-out is suitably suppressed, and if the composition ratio Rc is 0.85 or less, good hardness is obtained.

[0136] As shown in Table 2, in Examples 1, 7, and 8, which had good antibacterial and antiviral properties, the elemental analysis by XPS showed that the N element concentration was 0.80 atm% or more, the Si element concentration was 0.75 atm% or more, and the Cl element concentration was 0.35 atm% or more. On the other hand, in Examples 9 and 10, in which at least one of these element concentrations was below the above range, antibacterial properties were obtained but the antiviral properties were insufficient.

[0137] Furthermore, in Examples 1, 7, and 8, the elemental analysis by EDX revealed that the elemental concentration of Si was 0.20 atm % or more and the elemental concentration of Cl was 0.19 atm % or more, whereas in Examples 9 and 10, the elemental concentrations were below the above ranges.

[0138] In Examples 1, 7, and 8, the elution amount of Cl was 4.0 nmol / cm ２ On the other hand, in Examples 9 and 10, the amount of Cl eluted was below the above range. Therefore, it was confirmed that both antibacterial and antiviral properties were excellently obtained when the results of each elemental analysis were within the above range.

[0139] Furthermore, in Examples 1, 7, and 8, the elemental analysis by XPS showed that the elemental concentration of N was 4.00 atm% or less, the elemental concentration of Si was 4.50 atm% or less, and the elemental concentration of Cl was 2.90 atm% or less. However, in Comparative Example 5, in which the elemental concentrations exceeded the above ranges, bleed-out occurred.

[0140] Furthermore, in Examples 1, 7, and 8, the elemental analysis by EDX revealed that the elemental concentration of Si was 1.30 atm% or less and the elemental concentration of Cl was 1.40 atm% or less, whereas in Comparative Example 5, the elemental concentrations exceeded the above ranges.

[0141] In addition, in Examples 1, 7, and 8, the elution amount of Cl was 55.0 nmol / cm ２ On the other hand, in Comparative Example 5, the amount of Cl eluted exceeds the above range.

[0142] Therefore, it was confirmed that the occurrence of bleed-out due to excessive functional components can be suppressed by ensuring that the results of each elemental analysis are within the above ranges.

[0143] As described above, the above-described embodiments and examples can provide the following effects: (1) The functional layer contains an organic functional component and a resin component having an average hydroxyl value Hv of 100 mgKOH / g or more. This provides at least one of antibacterial and antiviral properties and can suppress an increase in haze and the occurrence of bleed-out.

[0144] (2) The functional layer contains an organic functional component and a resin component, and the water vapor permeability per unit thickness of the functional layer is 170 (g / m ２ This makes it possible to obtain at least one of antibacterial and antiviral properties, and also to suppress an increase in haze and the occurrence of bleed-out.

[0145] (3) The average hydroxyl value of the resin component is 200 mgKOH / g or less, thereby preventing deterioration of the mechanical properties of the functional layer. (4) The composition ratio Rc of the resin component is 0.40 or more, thereby preventing bleed-out. Furthermore, the composition ratio Rc of the resin component is 0.85 or less, thereby preventing deterioration of the mechanical properties.

[0146] (5) If the haze of the optical film is 3% or less, high transparency can be obtained. Furthermore, since the functional component is organic, it is easy to achieve a haze of 3% or less. (6) If the optical film is configured to contain fine particles for light scattering, an optical film with antiglare properties can be realized. Furthermore, if the haze of the optical film is 5% or more and 35% or less, good antiglare properties can be obtained. Furthermore, if the 1° reflection clarity of the optical film is 90 or less and the 5° reflection clarity is 60 or more, good antiglare properties can be obtained.

[0147] (7) When the average particle diameter of the light-scattering microparticles is 30% or more of the thickness of the resin layer, the light-scattering effect of the microparticles can be suitably obtained. (8) When the content of the light-scattering microparticles in the resin layer is 3.0% by mass or more and 20% by mass or less, the light-scattering effect of the microparticles can be suitably obtained and deterioration of the mechanical properties of the resin layer can be suppressed.

[0148] (9) When the pencil hardness of the surface of the optical film is 2H or more, good mechanical properties can be obtained. (10) When the thickness of the resin layer is 1.0 μm or more, the uniformity of the thickness of the resin layer, the applicability of the coating liquid for forming the resin layer, the mechanical strength of the resin layer, and, when the resin layer is a functional layer, the antibacterial activity and antiviral activity can be improved.

[0149] (11) When the thickness of the low refractive index layer is 30 nm or more and 300 nm or less, it is easy to cause light interference, and it is easy to obtain good scratch resistance and adhesion to the resin layer. (12) When the functional component is a silane coupling agent containing a quaternary ammonium salt in its molecular structure, it is suitable as an organic functional component.

[0150] (13) In elemental analysis of the surface of the optical film by XPS, the elemental concentration of N is 0.80 atm% or more and 4.00 atm% or less, the elemental concentration of Si is 0.75 atm% or more and 4.50 atm% or less, and the elemental concentration of halogen elements is 0.35 atm% or more and 2.90 atm% or less. With this configuration, both antibacterial and antiviral properties are obtained well, while bleeding out in the functional layer is suppressed.

[0151] (14) In elemental analysis by EDX of the surface of the optical film, the elemental concentration of Si is 0.20 atm% or more and 1.30 atm% or less, and the elemental concentration of halogen elements is 0.19 atm% or more and 1.40 atm% or less. With this configuration, both antibacterial and antiviral properties are obtained well, while bleeding out in the functional layer is suppressed.

[0152] (15) The amount of halogen elements eluted from the surface of the optical film measured by ion chromatography is 4.0 nmol / cm ２ 55.0 nmol / cm or more ２ According to this configuration, both antibacterial and antiviral properties are obtained satisfactorily, while bleeding out from the functional layer is suppressed.

[0153] (16) By providing a display device with the optical film, good optical and mechanical properties as well as antibacterial and antiviral properties can be obtained near the surface of the display device. In particular, in a display device equipped with a touch panel, the antibacterial and antiviral properties of the optical film can be highly beneficial.

[0154] The expression "at least one" used in this specification means "one or more" of the desired options. As an example, the expression "at least one" used in this specification means "only one option" or "both of two options" if the number of options is two. As another example, the expression "at least one" used in this specification means "only one option" or "any combination of two or more options" if the number of options is three or more.

[0155] 10, 10A, 10B... Optical film 20... Substrate 21... Resin layer 22... Low refractive index layer 100... Display device

Claims

1. An optical film comprising a substrate and a functional layer containing at least one of an antibacterial agent and an antiviral agent as a functional component and a resin component, wherein the functional component is an organic-based material, the ratio of the functional component to the resin component contained in the functional layer is 40% by mass or less, a first condition is that the average hydroxyl value of the resin component is 100 mgKOH / g or more, and a second condition is that the water vapor permeability per unit film thickness in the functional layer is 170 (g / m ２ ·day) / μm or more, and an optical film satisfying at least one of the first condition and the second condition.

2. The optical film according to claim 1, which satisfies the first condition and has an average hydroxyl value of the resin component of 200 mgKOH / g or less.

3. The optical film according to claim 1, wherein the structural units of the polymer contained in the resin component include a first structural unit having no hydroxyl group and a second structural unit having one or more hydroxyl groups, and the ratio of the second structural unit to all the structural units in the resin component is 0.40 or more.

4. The optical film according to claim 1, having a haze of 3% or less.

5. The optical film according to claim 1, comprising a resin layer supported on the substrate, wherein the functional layer includes the resin layer, and the resin layer contains fine particles for light scattering.

6. The optical film according to claim 5, wherein the average particle diameter of the fine particles is 30% or more of the thickness of the resin layer.

7. The optical film according to claim 5, wherein the content ratio of the fine particles in the resin layer is 3.0% by mass or more and 20% by mass or less.

8. The optical film according to claim 1, having a pencil hardness of 2H or more on the surface of the optical film.

9. The optical film according to claim 1, having a haze of 5% or more and 35% or less.

10. The optical film according to claim 1, having a 1° reflection clarity of 90 or less and a 5° reflection clarity of 60 or more.

11. The optical film according to claim 1, comprising a resin layer supported on the substrate, wherein the functional layer includes the resin layer, and the thickness of the resin layer is 1.0 μm or more.

12. The optical film according to claim 1, comprising a resin layer supported on the substrate and a low refractive index layer having a lower refractive index than the resin layer and covering the resin layer on the side opposite to the substrate with respect to the resin layer, wherein the functional layer includes at least the resin layer among the resin layer and the low refractive index layer, and the thickness of the low refractive index layer is 30 nm or more and 300 nm or less.

13. The optical film according to any one of claims 1 to 12, wherein the functional component is a silane coupling agent containing a quaternary ammonium salt in its molecular structure, and the quaternary ammonium salt contains halide ions.

14. The optical film has a first surface and a second surface on the side opposite to the first surface and which is the surface of the base material. In the elemental analysis by X-ray photoelectron spectroscopy with respect to the first surface, the elemental concentration of N is 0.80 atm% or more and 4.00 atm% or less, and the elemental concentration of Si is 0.75 atm% or more and 4.50 atm% or less, and the elemental concentration of the halogen element is 0.35 atm% or more and 2.90 atm% or less. The optical film according to claim 13.

15. The optical film has a first surface and a second surface on the side opposite to the first surface and which is the surface of the base material. In the elemental analysis by energy dispersive X-ray spectroscopy with respect to the first surface, the elemental concentration of Si is 0.20 atm% or more and 1.30 atm% or less, and the elemental concentration of the halogen element is 0.19 atm% or more and 1.40 atm% or less. The optical film according to claim 13.

16. The optical film has a first surface and a second surface opposite to the first surface and being the surface of the base material. The elution amount of halogen elements from the first surface measured using ion chromatography is 4.0 nmol / cm ２ or more and 55.0 nmol / cm ２ or less. The optical film according to claim 13.

17. A display device comprising the optical film according to any one of claims 1 to 12, wherein the optical film is located on a display surface on which an image is displayed. The display device.

Images