Optical films and display devices

Abstract

An optical film comprising a substrate and a functional layer, the functional layer comprising a functional component as at least one of an antibacterial agent and an antiviral agent, and a resin component. The functional component is an organic material, and the proportion of the functional component relative to the resin component contained in the functional layer is 40% by mass or less. The optical film satisfies at least one of the following first and second conditions: the first condition is that the average hydroxyl value of the resin component is 100 mg KOH / g or more; the second condition is that the water vapor transmission rate per unit thickness of the functional layer is 170 g / m². 2 ·days / μm or more.

Description

Technical Field

[0001] This disclosure relates to optical films and display devices having optical films. Background Technology

[0002] Optical films have the function of controlling the reflection and transmission of light. For example, optical films are applied to the surface of a display device for the purpose of facilitating the viewing of the image on the display device.

[0003] For optical films, in addition to optical properties such as haze, various properties such as hardness and scratch resistance are required depending on the application. Furthermore, due to the recent increase in hygiene awareness, the demand for optical films with antibacterial and antiviral properties has also increased. To impart antibacterial and antiviral properties to optical films, antibacterial and antiviral agents can be added to the resin constituting the optical film. As antibacterial and antiviral agents, metal-based particles containing silver or silver compounds are widely used (see, for example, Patent Document 1).

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent No. 6720639 Summary of the Invention

[0005] The problem that the invention aims to solve When optical films contain metallic particles as antibacterial and antiviral agents, an increase in the content of these particles leads to greater light scattering on the surface or within the film, resulting in increased haze. Therefore, the content of metallic particles is limited to achieve the desired optical properties in the film. This is particularly true for optical films characterized by high transparency, such as those requiring haze below 1%, where it is difficult to simultaneously achieve antibacterial / antiviral properties and optical characteristics. Furthermore, restrictions on the use of silver-based antibacterial and antiviral agents are increasing in Europe.

[0006] On the other hand, among compounds that can be used as antibacterial and antiviral agents, in addition to metal particles, there are also organic materials such as quaternary ammonium salts. Since organic antibacterial and antiviral agents are not particulate, they are less likely to cause an increase in haze. However, generally speaking, the curing resin, which is the main component of the optical film, is hydrophobic in order to improve the film's strength and hardness; in contrast, most organic antibacterial and antiviral agents are hydrophilic. Therefore, if a layer containing organic antibacterial and antiviral agents mixed in the aforementioned curing resin is to be formed as a constituent layer of the optical film, phase separation and exudation will occur during the curing of this layer.

[0007] Methods for solving problems This document describes various methods for solving the aforementioned problems using optical films and display devices.

[0008] [Method 1] An optical film comprising a substrate and a functional layer, the functional layer comprising a functional component as at least one of an antibacterial agent and an antiviral agent and a resin component, wherein the functional component is an organic material, the proportion of the functional component relative to the resin component contained in the functional layer is 40% by mass or less, and the optical film satisfies at least one of the following first condition and the following second condition: The first condition is that the average hydroxyl value of the resin components is ≥100 mg KOH / g. The second condition is that the water vapor permeability per unit membrane thickness in the functional layer is 170 (g / m²). 2 ·days / μm or more.

[0009] Based on the above composition, at least one of antibacterial and antiviral properties can be obtained, and the increase in fog level and the occurrence of exudation in the functional layer can be suppressed.

[0010] [Method 2] The optical film according to [Method 1] satisfies the first condition, and the average hydroxyl value of the resin component is less than 200 mg KOH / g.

[0011] Based on the above structure, it is possible to suppress the reduction of mechanical properties such as strength in the functional layer.

[0012] [Method 3] According to the optical film of [Method 1] or [Method 2], wherein the polymer structural units contained in the resin component include a first structural unit without 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.

[0013] Based on the above structure, the occurrence of exudation in the functional layer can be appropriately suppressed.

[0014] [Method 4] An optical film according to any one of [Method 1] to [Method 3], wherein the haze of the optical film is 3% or less.

[0015] Based on the above composition, high transparency can be achieved. Moreover, by using organic functional components, it is easy to achieve a haze of less than 3%.

[0016] [Method 5] An optical film according to any one of [Method 1] to [Method 4], wherein the optical film comprises a resin layer supported by the substrate, the functional layer comprises the resin layer, and the resin layer comprises microparticles for light scattering.

[0017] Based on the above configuration, an optical film with anti-glare properties can be achieved.

[0018] [Method 6] According to the optical film of [Method 5], wherein the average particle size of the microparticles is more than 30% of the thickness of the resin layer.

[0019] Based on the above configuration, it is possible to obtain a suitable light scattering effect caused by the particles.

[0020] [Method 7] The optical film according to [Method 5] or [Method 6], wherein the content of the microparticles in the resin layer is 3.0% by mass or more and 20% by mass or less.

[0021] Based on the above configuration, the light scattering effect caused by the particles can be appropriately obtained, and the reduction of the mechanical properties of the resin layer can be suppressed.

[0022] [Method 8] An optical film according to any one of [Method 1] to [Method 7], wherein the pencil hardness of the surface of the optical film is 2H or higher.

[0023] Based on the above configuration, good mechanical properties can be obtained.

[0024] [Method 9] An optical film according to any one of [Method 1] to [Method 3] and [Method 5] to [Method 7], wherein the haze of the optical film is 5% or more and 35% or less.

[0025] Based on the above configuration, good anti-glare performance can be achieved.

[0026] [Method 10] An optical film according to any one of [Method 1] to [Method 3], [Method 5] to [Method 7] and [Method 9], wherein the reflectance of the optical film at 1° is 90 or less, and the reflectance at 5° is 60 or more.

[0027] Based on the above configuration, good anti-glare performance can be achieved.

[0028] [Method 11] An optical film according to any one of [Method 1] to [Method 10], wherein the optical film has a resin layer supported by the substrate, the functional layer includes the resin layer, and the resin layer has a thickness of 1.0 μm or more.

[0029] Based on the above composition, the uniformity of the resin layer thickness, the coatability of the coating liquid used to form the resin layer, the mechanical strength of the resin layer, and the antibacterial and antiviral activities when the resin layer is a functional layer are improved.

[0030] [Method 12] An optical film according to any one of [Method 1] to [Method 11], wherein the optical film comprises: a resin layer supported by 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, the functional layer comprising at least the resin layer and the low refractive index layer, the thickness of the low refractive index layer being 30 nm or more and 300 nm or less.

[0031] Based on the above structure, light interference is easily generated, and good scratch resistance and adhesion to the resin layer are easily obtained.

[0032] [Method 13] An optical film according to any one of [Method 1] to [Method 12], wherein the functional component is a silane coupling agent whose molecular structure contains a quaternary ammonium salt, wherein the quaternary ammonium salt contains a halide ion.

[0033] Based on the above composition, it is suitable as a functional component of organic systems.

[0034] [Method 14] According to the optical film of [Method 13], the optical film has a first surface and a second surface that is the opposite side of the first surface and is a surface of the substrate. In the elemental analysis of the first surface by X-ray photoelectron spectroscopy, the elemental concentration of N is 0.80 atomic% or more and 4.00 atomic% or less, the elemental concentration of Si is 0.75 atomic% or more and 4.50 atomic% or less, and the elemental concentration of halogens is 0.35 atomic% or more and 2.90 atomic% or less.

[0035] Based on the above composition, both antibacterial and antiviral properties can be obtained well, and on the other hand, exudation in the functional layer can be inhibited.

[0036] [Method 15] According to the optical film of [Method 13], the optical film has a first surface and a second surface that is the opposite side of the first surface and is a surface of the substrate. In the elemental analysis of the first surface using energy-dispersive X-ray spectrometry, the elemental concentration of Si is 0.20 atomic% or more and 1.30 atomic% or less, and the elemental concentration of halogens is 0.19 atomic% or more and 1.40 atomic% or less.

[0037] Based on the above composition, both antibacterial and antiviral properties can be obtained well, and on the other hand, exudation in the functional layer can be inhibited.

[0038] [Method 16] According to the optical film of [Method 13], wherein the optical film has a first side and a second side that is the side opposite to the first side and is a side of the substrate, and the leaching amount of halogen element from the first side, as determined by ion chromatography, is 4.0 nmol / cm³. 2 Above and 55.0 nmol / cm 2 the following.

[0039] Based on the above composition, both antibacterial and antiviral properties can be obtained well, and on the other hand, exudation in the functional layer can be inhibited.

[0040] [Method 17] A display device comprising an optical film as described in any one of [Method 1] to [Method 16], wherein the optical film is located on a display surface displaying an image.

[0041] Based on the above configuration, antibacterial and antiviral properties can be obtained near the surface of the display device, as well as good optical and mechanical properties.

[0042] Invention Effects According to this disclosure, at least one of antibacterial and antiviral properties can be obtained in the optical film, and the increase of haze and the occurrence of exudation can be suppressed. Attached Figure Description

[0043] Figure 1 This is a diagram showing the cross-sectional structure of a first example of an optical film according to one embodiment.

[0044] Figure 2 This is a diagram showing a cross-sectional structure of a second example of an optical film according to one embodiment.

[0045] Figure 3 This is a diagram illustrating the configuration of a display device according to one embodiment. Detailed Implementation

[0046] An embodiment of the optical film and display device will be described with reference to the accompanying drawings.

[0047] [Optical film layer composition: first example] Figure 1This section presents a first example of the layer structure of the optical film 10. The optical film 10A of this first example includes a substrate 20 and a resin layer 21. The resin layer 21 is supported by the substrate 20. In this first example, the resin layer 21 contains a resin component and a functional component having at least one of antibacterial and antiviral properties. Furthermore, the surface of the resin layer 21 opposite to the surface in contact with the substrate 20 is the surface of the optical film 10A. This surface of the optical film 10A is an example of a first surface, exhibiting antibacterial and antiviral effects. The surface of the optical film 10A opposite to the first surface is a second surface, which is the surface of the substrate 20. In this first example, the resin layer 21 corresponds to a functional layer containing the functional component.

[0048] The following is a detailed explanation of the composition of each layer.

[0049] <Substrate> The material and thickness of the substrate 20 are only required to allow for the formation of the resin layer 21 on the substrate 20. The substrate 20 may be, for example, a resin film that is light-transparent to the visible area. Materials for the resin film include, for example, polyester, polypropylene, polystyrene, nylon, polycarbonate, polyacrylonitrile, polyimide, triacetyl cellulose, etc. From the viewpoint of ease of processing the substrate 20, the thickness of the substrate 20 is preferably 12 μm or more, more preferably 20 μm or more. If the thickness of the substrate 20 is 12 μm or more, it is easier to obtain good strength and quality of the substrate 20. The substrate 20 can be a single-layer structure or a multi-layer structure.

[0050] <Resin Layer> The functional components contained in resin layer 21 are hydrophilic organic materials. Furthermore, the functional components are not in particulate form. The functional components can function as either an antibacterial agent or an antiviral agent, or as both, or they can function as either an antibacterial agent or an antiviral agent depending on factors such as the dosage.

[0051] Furthermore, in this embodiment, the functional ingredient is defined as being hydrophilic when it can be uniformly dissolved or dispersed when 10g of water is added to 100g of the functional ingredient.

[0052] Specific examples of functional components include quaternary ammonium salts, triclosan, biguanides, chitosan, terpenes, and physalisol. For instance, a functional component can be a silane coupling agent whose molecular structure contains a quaternary ammonium salt as a functional group that reacts with organic materials.

[0053] The proportion of the functional component to the resin component in the resin layer 21 is less than 40% by mass. This suppresses exudation during the formation of the resin layer 21 caused by excessive functional components.

[0054] From the viewpoint of improving antibacterial and antiviral activity, the proportion of the functional component relative to the resin component in the resin layer 21 is preferably 3% by mass or more, and more preferably 5% by mass or more. From the viewpoint of improving the dispersibility of the functional component, the proportion of the functional component relative to the resin component in the resin layer 21 is preferably 30% by mass or less, and more preferably 20% by mass or less.

[0055] By using non-particulate functional components, the haze of the optical film 10A can be prevented even if the resin layer 21 contains functional components.

[0056] The resin component contained in resin layer 21 can be either a UV-curable resin or a thermosetting resin. UV-curable resins are cured products of photopolymerizable compounds. Examples of photopolymerizable compounds include monofunctional, difunctional, or trifunctional (meth)acrylate compounds and urethane (meth)acrylate compounds. Furthermore, "(meth)acrylate" is a general term for acrylates and methacrylates. Examples of thermosetting resins include acrylic resins, polyurethane resins, and epoxy resins. The resin component contained in resin layer 21 can be one type or two or more types.

[0057] The resin layer 21 satisfies at least one of the following first and second conditions.

[0058] First condition: The average hydroxyl value (Hv) of the resin components contained in resin layer 21 is above 100 mg KOH / g.

[0059] Second condition: The water vapor permeability Wx per unit film thickness of resin layer 21 is 170 (g / m²). 2 ·day) / μm or more.

[0060] The first and second conditions will be explained in detail below.

[0061] (first condition) The first condition is that the average hydroxyl value Hv of the resin components contained in the resin layer 21 is 100 mg KOH / g or higher. The average hydroxyl value Hv is a measured value obtained according to JIS K0070 using the resin layer 21 or its material as a sample, or a calculated value obtained based on the known hydroxyl value of the material.

[0062] For example, in the case where the resin composition is a polymer formed from multiple monomers, the average hydroxyl value Hv is obtained by multiplying the hydroxyl value of each monomer by its mole fraction, and then summing these products for all monomers. The mole fraction of a monomer is the proportion of that monomer's mass relative to the total monomer mass. Furthermore, these monomers are either monomers without hydroxyl groups or monomers with hydroxyl groups that do not participate in the polymerization reaction.

[0063] Furthermore, for example, when the resin composition contains multiple polymers and the hydroxyl value of each polymer is known, the average hydroxyl value Hv is obtained by multiplying the hydroxyl value of each polymer by its mole fraction, and then summing the products of all polymers. The mole fraction of a polymer is the proportion of the polymer's mass relative to the total mass of the polymer. For each polymer, the mass obtained by dividing the polymer's mass by its number-average molecular weight is considered the polymer's mass.

[0064] By making the average hydroxyl value Hv above 100 mg KOH / g, the affinity between the resin components and the functional components can be obtained, thus inhibiting phase separation and exudation during the formation of the resin layer 21.

[0065] Furthermore, the average hydroxyl value Hv is preferably below 200 mg KOH / g. This prevents an excessive number of hydrophilic groups in the resin composition, thus suppressing the reduction of mechanical properties such as strength and hardness of the resin layer 21.

[0066] (Second condition) The second condition is that the water vapor permeability Wx per unit film thickness of resin layer 21 is 170 (g / m²). 2 •day) / μm or higher. Water vapor transmission rate is determined according to JIS Z0208 (Test method for moisture permeability of moisture-proof packaging materials (cup method)). The test conditions for water vapor transmission rate are: temperature: 40℃, humidity: 90%RH, test time: 24 hours.

[0067] For example, the water vapor transmittance Wx per unit thickness of resin layer 21 is determined based on the measurement of water vapor transmittance of optical film 10A and water vapor transmittance of substrate 20 alone. In detail, when the water vapor transmittance of substrate 20 is set as WA and the water vapor transmittance of optical film 10A, i.e., the water vapor transmittance of the laminate of substrate 20 and resin layer 21, is set as WB, the water vapor transmittance WX of resin layer 21 is determined by the following (Equation 1).

[0068] WX=WA×WB / (WA-WB) (Formula 1) Furthermore, the film thickness of resin layer 21 is set as t, and the water vapor permeability Wx per unit film thickness of resin layer 21 is calculated by the following (Equation 2).

[0069] Wx = WX / t (Equation 2) A higher water vapor permeability Wx indicates a higher affinity of the resin components in resin layer 21 for water. With a water vapor permeability Wx of 170 (g / m²), the desired result is a higher water vapor permeability. 2 With a thickness of ·day) / μm or more, good affinity between resin components and functional components can be obtained, thus suppressing phase separation and exudation during the formation of resin layer 21.

[0070] Furthermore, the greater the water vapor permeability Wx, the easier it is for the hydrophilic functional components to pass through the resin layer 21 and be exposed to the surface of the optical film 10A. Therefore, the functional components can easily come into contact with bacteria and viruses and exert antibacterial and antiviral properties.

[0071] Water vapor transmission rate (Wx) is correlated with the average hydroxyl value (Hv), with a tendency for a higher average hydroxyl value (Hv) to result in a higher water vapor transmission rate (Wx). Using resin components with a high average hydroxyl value (Hv) can improve water vapor transmission rate (Wx).

[0072] On the other hand, the higher the water vapor transmission rate Wx, the fewer cross-linked portions of the resin in the resin layer 21. Therefore, in order to suppress the reduction of mechanical properties such as strength and hardness of the resin layer 21, the water vapor transmission rate Wx is preferably 450 (g / m²). 2 Below ·day) / μm.

[0073] Further description is given of other features of resin layer 21. The following features are also applicable if resin layer 21 satisfies either the first condition or the second condition.

[0074] The resin component preferably comprises a first structural unit as a structural unit without hydroxyl groups and a second structural unit as a structural unit having one or more hydroxyl groups. One structural unit in the resin component refers to a structure derived from one monomer molecule. When the resin component comprises multiple polymers, the structural units of the resin component include the structural units of each polymer. The resin component may comprise a polymer having both a first and a second structural unit in one molecule, or it may comprise a polymer consisting only of the first structural unit and a polymer having the second structural unit in one molecule.

[0075] By including both first and second structural units in the resin composition, the mechanical properties of the resin layer 21 can be easily improved compared to the case where all structural units of the resin composition are second structural units.

[0076] The first structural unit is, for example, derived from acrylate monomers that do not possess hydroxyl groups, such as pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate. Furthermore, examples of polymers composed solely of the first structural unit include acrylic resins and polyurethane resins derived from these monomers.

[0077] The second structural unit is, for example, derived from acrylate monomers containing hydroxyl groups, such as pentaerythritol triacrylate or glycerol triacrylate. Other examples of polymers containing the second structural unit include acrylic resins or other hydrophilic resins derived from monomers containing these monomers.

[0078] The ratio of the second structural unit to all structural units in the resin composition, i.e., the composition ratio Rc, is preferably 0.40 or higher. When the resin composition contains multiple polymers, "all structural units in the resin composition" refers to all structural units in all polymers.

[0079] For example, when the resin composition is a polymer formed from a first monomer without hydroxyl groups and a second monomer with hydroxyl groups, the composition ratio Rc is the mole fraction of the second monomer relative to the total monomer mass. That is, when the amount of the first monomer is set as A and the amount of the second monomer is set as B, the composition ratio Rc is expressed as B / (A+B). Furthermore, these monomers are either monomers without hydroxyl groups or monomers with hydroxyl groups that do not participate in the polymerization reaction.

[0080] Furthermore, for example, when the resin composition contains multiple polymers and the composition ratio Rcp of each polymer is known, the composition ratio Rc of the resin composition is obtained by calculating the product of the composition ratio Rcp of each polymer and its mole fraction for each polymer, and then summing the products of all polymers. The mole fraction of a polymer is the proportion of the mass of that polymer relative to the total mass of the polymer. For each polymer, the mass obtained by dividing the mass of the polymer by its number-average molecular weight is considered as the mass of the polymer.

[0081] By setting the composition ratio Rc to 0.40 or higher, a sufficient proportion of the second structural unit can be obtained, thus achieving appropriate affinity between the resin component and the functional component. On the other hand, the composition ratio Rc is preferably 0.85 or lower. This ensures a sufficient proportion of the first structural unit, thereby suppressing any reduction in the mechanical properties of the resin layer 21.

[0082] The resin layer 21 may also contain microparticles for adjusting the light scattering properties in the optical film 10A. By containing microparticles, the surface roughness of the optical film 10A can be adjusted, thereby controlling the light scattering properties on the surface of the optical film 10A. By giving the surface of the optical film 10A appropriate light scattering properties, the diffuse reflection component in the reflected light on the surface of the optical film 10A can be increased while the specular reflection component is suppressed, thus suppressing the reflection of surrounding light into the optical film 10A.

[0083] Furthermore, by including microparticles, the light scattering properties within the resin layer 21 can also be controlled. By controlling the light scattering properties of the surface of the optical film 10A and the interior of the resin layer 21, the haze of the optical film 10A can be controlled, thereby adjusting the transparency of the optical film 10A. In this embodiment, as described above, since the functional component is a non-particulate organic material, the haze of the optical film 10A can be controlled regardless of the content of the functional component.

[0084] The microparticles can be organic or inorganic. The resin layer 21 may contain one type of microparticle, or two or more types of microparticles that differ in at least one of their material and average particle size. The average particle size is the median particle size (D50) based on volume. The average particle size is preferably 30% or more of the thickness of the resin layer 21, more preferably 50% or more and 80% or less 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 microparticles in the thickness direction. If the average particle size is within the above range, a suitable light scattering effect caused by the microparticles can be obtained.

[0085] The proportion of microparticles in resin layer 21 is preferably 3.0% by mass or more and 20% by mass or less. If the proportion of microparticles is 3.0% by mass or more, a suitable light scattering effect caused by the microparticles can be obtained. If the proportion of microparticles is 20% by mass or less, the resin content will not become too low, thus suppressing the reduction of the mechanical properties of resin layer 21.

[0086] Organic microparticles are resin particles composed of light-transmitting resin materials such as acrylic resins, polystyrene resins, styrene-(meth)acrylate copolymers, polyethylene resins, epoxy resins, silicone resins, polyvinylidene fluoride, and polyvinyl fluoride resins.

[0087] Inorganic microparticles can be used as materials to regulate the sedimentation and aggregation of organic microparticles. Examples of inorganic microparticles include silica microparticles, metal oxide microparticles, and mineral microparticles. Examples of silica microparticles include colloidal silica and silica microparticles with surface modifications using reactive functional groups such as (meth)acryloyl groups. Examples of metal oxide microparticles include aluminum oxide, zinc oxide, tin oxide, antimony oxide, indium oxide, titanium dioxide, and zirconium dioxide. Examples of mineral microparticles include mica, synthetic mica, vermiculite, montmorillonite, iron montmorillonite, bentonite, bedesite, soapstone, lithium montmorillonite, magnesia, chloromethoxide, sodium silicate, illite, hydrous sodium silicate, layered titanate, montmorillonite, and synthetic montmorillonite.

[0088] The resin layer 21 may contain various additives. Examples of additives include ultraviolet absorbers, antistatic agents, leveling agents, thickeners, etc. By including additives, the ultraviolet absorption function, antistatic function, etc., of the resin layer 21 can be realized, and the coatability or quality can be improved.

[0089] From the viewpoints of improving the uniformity of the resin layer 21 thickness, the coatability of the coating liquid used to form the resin layer 21, the mechanical strength of the resin layer 21, and its antibacterial and antiviral activities, the thickness of the resin layer 21 is preferably 0.5 μm or more, more preferably 1 μm or more. 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, the thickness of the resin layer 21 is preferably 10 μm or less, more preferably 5 μm or less.

[0090] Furthermore, the thickness of resin layer 21 is the film thickness of the portion of resin layer 21 that does not contain particles in the thickness direction. The thickness of optical film 10 and the thickness of each layer constituting optical film 10 are the average of sample values ​​of thickness in the cross-section of the object being measured. The sample values ​​of thickness are the measured values ​​of thickness at 10 points spaced at intervals of 1 mm or more in the cross-section of the object being measured, and the difference between these measured values ​​and the average of these measured values ​​is within 50% of the average value.

[0091] The resin layer 21 is formed by coating the upper surface of the substrate 20 with a coating liquid for forming the resin layer 21, i.e., a resin layer coating liquid, and then curing the film formed therefrom. The resin layer coating liquid contains compounds of the resin components used to form the resin layer 21, functional components, polymerization initiators, and other auxiliary agents as needed. In the case of forming a resin layer 21 containing particles, the resin layer coating liquid further contains particles.

[0092] The resin coating can be applied using known methods such as rod coating, spin coating, offset coating, gravure coating, roller coating, and mold coating. The curing method for the coated film can be any method corresponding to the curing type of the resin components, such as ultraviolet irradiation or heat drying.

[0093] [Layer Composition of Optical Films: Example 2] Figure 2 This is a second example of the layer composition of the optical film 10. In addition to the substrate 20 and the resin layer 21, the optical film 10B of the second example of the optical film 10 also includes a low refractive index layer 22. The low refractive index layer 22 has a lower refractive index than the resin layer 21 and has the function of suppressing surface reflection of the optical film 10B by utilizing light interference.

[0094] A low-refractive-index layer 22 is located on the resin layer 21. When the surface of the resin layer 21 has unevenness, the low-refractive-index layer 22 has a surface shape that follows the unevenness of the resin layer 21. In the second example, the surface of the low-refractive-index layer 22 opposite to the surface contacting the resin layer 21 is the surface of the optical film 10B. The surface of the optical film 10B is an example of a first surface. Similarly, in the first example, the surface of the optical film 10B opposite to the first surface is a second surface, which is the surface of the substrate 20.

[0095] The low-refractive-index layer 22 comprises an ultraviolet-curable resin or a thermosetting resin. As such a resin component, components exemplified as those included in the resin layer 21 can be used. Additionally, the low-refractive-index layer 22 may also contain a refractive index modifier for reducing the refractive index of the low-refractive-index layer 22. Examples of refractive index modifiers include fluoride microparticles such as lithium fluoride, magnesium fluoride, sodium hexafluoroaluminate, and aluminum fluoride, as well as silica microparticles. Using silica microparticles with internal pores, such as porous silica microparticles or hollow silica microparticles, is effective for reducing the refractive index of the low-refractive-index layer 22.

[0096] The low refractive index layer 22 can contain various additives. Examples of additives include ultraviolet absorbers, antistatic agents, leveling agents, thickeners, etc. By including additives, the ultraviolet absorption function, antistatic function, etc., of the low refractive index layer 22 can be enhanced, and its coatability or quality can be improved.

[0097] 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. 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 can be maintained well.

[0098] In the second example of the optical film 10B, 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 a functional layer. A functional layer containing a functional component is acceptable as long as it satisfies at least one of the first and second conditions described in the first example. In addition, the resin composition ratio Rc of the functional layer preferably also satisfies the conditions described in the first example.

[0099] The components illustrated in the first example can be used as functional components. The mass ratio of the functional component to the resin component in the functional layer is 40% by mass or less. Furthermore, 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% by mass or more and 50% by mass or less.

[0100] Since the resin layer 21 is thicker than the low-refractive-index layer 22, the degree of freedom in adjusting the content of functional components can be increased if the resin layer 21 contains functional components. On the other hand, if the low-refractive-index layer 22 contains functional components, the functional components are distributed near the surface of the optical film 10B, thus easily improving the antibacterial / antiviral effect.

[0101] When the resin layer 21 contains functional components, the functional components dissolve from the surface of the optical film 10B through the low refractive index layer 22, thereby acting on bacteria and viruses. Therefore, the low refractive index layer 22 preferably satisfies at least one of the first and second conditions, and the resin composition of the low refractive index layer 22 preferably satisfies the conditions described in the first example in terms of the ratio Rc.

[0102] The low refractive index layer 22 is formed by coating the upper surface of the resin layer 21 with a coating liquid for forming the low refractive index layer 22, i.e., a low refractive index layer coating liquid, and then curing the film formed therefrom. The low refractive index layer coating liquid contains compounds of the resin components for forming the low refractive index layer 22, polymerization initiators, and other auxiliary agents as needed, and further contains refractive index modifiers and functional components depending on the composition of the low refractive index layer 22.

[0103] Low-refractive-index coatings can be applied using known methods such as rod coating, spin coating, offset coating, gravure coating, roller coating, and die coating. The curing method for the coated film can be any method corresponding to the curing type of the resin components, such as ultraviolet irradiation or heat drying.

[0104] [Properties of optical films] As characteristics of the optical film 10, its optical properties, mechanical properties, and elemental composition will be described. The following properties are common to the optical films in the first and second examples.

[0105] <Optical Properties> When the resin layer 21 does not contain particles for light scattering, the haze of the optical film 10 is preferably 3% or less. With this configuration, high transparency can be obtained for the optical film 10, and the visibility through the optical film 10 is improved.

[0106] When the resin layer 21 contains particles for light scattering, the haze of the optical film 10 is preferably 5% or more and 35% or less. With this configuration, it is possible to suppress the reflection of the surroundings in the optical film 10, and on the other hand, it is possible to suppress excessive reduction of visibility through the optical film 10.

[0107] Furthermore, the haze mentioned above is the haze transmitted through the light, measured according to JIS K7136.

[0108] Anti-glare is achieved when resin layer 21 contains microparticles for light scattering. Anti-glare performance can be evaluated using reflectance at 1° and 5°. Reflectance is the value obtained by subtracting reflectance haze (%) from 100. Reflectance haze is a parameter representing the degree of diffusion of reflected light. It is determined by irradiating the surface of the optical film 10 onto the blackboard with light from a light source position with 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 positive reflection direction at the light-receiving position. Reflectance haze at any angle θ centered on the positive reflection direction is the percentage of the average of the reflectance intensity at angle + θ and angle - θ relative to the reflectance intensity at the positive reflection direction. The value obtained by subtracting the aforementioned reflectance haze at angle θ from 100 is the reflectance haze at angle θ. The measurement conditions are as described below, and other conditions are measured according to ASTM D5767.

[0109] • Slit width: 1mm • Objective lens: 16mm • Distance from the surface of the optical film to the light-receiving position: 300mm When the resin layer 21 contains particles for light scattering, it is preferable that the reflection sharpness in the optical film 10 is 90° or less at an angle θ of 1° and 60° or more at an angle θ of 5°. This suppresses reflection components relative to the viewing direction and allows for adequate reflection components near the viewing direction. Consequently, the image projected onto the surface of the optical film 10 is moderately blurred, resulting in good anti-glare performance.

[0110] <Mechanical Properties> The pencil hardness of the surface of the optical film 10, i.e., the scratch hardness using the pencil method, is preferably 2H or higher. If the pencil hardness is 2H or higher, the surface of the optical film 10 is less likely to be damaged. The pencil hardness is measured according to JIS K5600-5-4.

[0111] <Elemental Composition> In the optical film 10, the functional components exert their antibacterial and antiviral properties through contact with bacteria and viruses. Therefore, the more functional components are distributed near the surface of the optical film 10, the higher the antibacterial and antiviral properties. Thus, 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 even without conducting long-term antibacterial and antiviral tests.

[0112] The following describes a preferred configuration of the elemental composition near the surface of the optical film 10, 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 may contain, for example, halide ions such as chloride ions.

[0113] In the elemental analysis of the surface of the optical film 10 using X-ray photoelectron spectroscopy (XPS), the preferred elements are: N concentration of 0.80 atomic% or more and 4.00 atomic% or less, Si concentration of 0.75 atomic% or more and 4.50 atomic% or less, and halogen element concentration of 0.35 atomic% or more and 2.90 atomic% or less.

[0114] Based on the above configuration, functional components are sufficiently distributed on the surface of the optical film 10, thus achieving both good antibacterial and antiviral properties. On the other hand, since there are not excessive functional components, exudation in the functional layer can be suppressed.

[0115] In the elemental analysis of the surface of the optical film 10 using energy dispersive X-ray spectroscopy (EDX), it is preferred that the elemental concentration of Si is 0.20 atomic% or more and 1.30 atomic% or less, and the elemental concentration of halogens is 0.19 atomic% or more and 1.40 atomic% or less.

[0116] Based on the above composition, functional components are sufficiently distributed on and around the surface of the optical film 10, thus achieving both good antibacterial and antiviral properties. On the other hand, since there are not excessive functional components, exudation from the functional layer can be suppressed. According to EDX, elemental analysis at depths deeper than XPS is possible, thus enabling analysis that also takes into account the functional components that act on bacteria and viruses after dissolving from the vicinity of the surface of the optical film 10.

[0117] The halogen leaching amount from the surface of the optical film 10, as determined by ion chromatography, is preferably 4.0 nmol / cm². 2 Above and 55.0 nmol / cm 2 The above-mentioned dissolution amount is the amount of halide ions dissolved per unit area of ​​the surface when the surface of the optical film 10 is sealed with pure water for 24 hours.

[0118] The leaching amount of halogen elements includes not only the area near the surface of the optical film 10 but also the functional components distributed within it. This indicates whether the quaternary ammonium ions constituting the functional components readily emerge from the optical film 10, i.e., whether the functional components readily act on bacteria and viruses. If the leaching amount of halogen elements is within the aforementioned range, both antibacterial and antiviral properties can be effectively obtained. On the other hand, since there is not an excessive amount of functional components, exudation from the functional layer can be suppressed.

[0119] The samples used in the determination of the leaching amount of halogen elements are obtained in the following order (a) to (c).

[0120] (a) Prepare a test piece by forming the optical film 10 into a square shape with one side of 4 cm or more, and drop 0.4 mL of pure water onto the surface of the test piece, which serves as the surface of the optical film 10. Then, make a polyethylene covering film with one side of 4 cm tightly adhere to the surface of the test piece after the pure water has been added. As a result, the area covered by the covering film on the surface of the test piece is uniformly wetted by pure water. Therefore, the area of ​​the test object for the leaching of halogen elements is 16 cm². 2 .

[0121] (b) Place the test piece treated in (a) above in a petri dish and place the petri dish in an environment with a temperature of 35±1℃ and a humidity of 90%RH or higher for 24 hours.

[0122] (c) After the treatment in (b) above, rinse the surface of the test piece with 2.5 mL of pure water, and recover the pure water used in rinsing as the sample used for the determination of the leaching amount of halogen elements.

[0123] Furthermore, the elemental composition related to the functional components near the surface of the aforementioned optical film 10 can be adjusted by the content ratio of the functional components in the functional layer, the presence and content ratio of additives such as leveling agents in the functional layer.

[0124] [Composition of the display device] like Figure 3 As shown, the display device 100 includes an optical film 10 and a main body 30 with image display function. The display surface 30S, which is the surface of the main body 30, is the surface for displaying images, 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 located on the display surface 30S, and the back of the optical film 10 is adhered to the display surface 30S.

[0125] In particular, when the display surface 30S is a touch panel surface, the user will frequently touch the display device 100, so the optical film 10 has high benefits in terms of antibacterial and antiviral properties.

[0126] Specific examples of display device 100 include smartphones, tablet terminals, personal computers, portable game consoles, music playback devices, televisions, monitors, e-book reading terminals, digital cameras, head-mounted displays, navigation devices, copiers, fax machines, printers, multifunction printers, vending machines, automatic teller machines (ATMs), personal authentication devices, optical communication devices, etc.

[0127] [Example] The optical films described above will be explained using specific embodiments and comparative examples.

[0128] (Example 1) The following materials are mixed to prepare a coating solution, i.e., a resin layer coating solution, for forming a resin layer. Furthermore, the following descriptions of each material in parts by mass indicate the relative mass ratio of each material.

[0129] • Photopolymerizable compound: 100 parts by weight of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry). • Photopolymerization initiator: 5.0 parts by weight of 1-hydroxycyclohexylphenyl ketone (Omnirad 184, manufactured by IGM Resins BV). • Functional ingredient: Quaternary ammonium salt antibacterial and antiviral agent (silane coupling agent) (KBM-9418-40, manufactured by Shin-Etsu Chemical Industry) 10.0 parts by weight (details: active ingredient 4.0 parts by weight, solvent (methanol) 6.0 parts by weight) • Additive: Leveling agent (GRANDIC PC4300, manufactured by DIC) 0.5 parts by weight Solvent: 110 parts by weight of toluene A 60 μm thick triacetyl cellulose membrane (TJ40, Fujifilm) was used as the substrate. The resin coating solution was applied to the surface of the substrate using a rod coater. The resulting coating was dried at 100°C for 1 minute using a dryer, and then cured by ultraviolet light irradiation under a nitrogen atmosphere (oxygen concentration below 500 ppm), thus forming the resin layer. The coating thickness was 5 μm, and the ultraviolet light was applied using a high-pressure mercury UV device with a cumulative exposure of 200 mJ / cm². 2 The film is irradiated in a manner that yields the optical film of Example 1, which comprises a substrate and a resin layer.

[0130] (Example 2) Except for changing the photopolymerizable compound to the following substances compared to Example 1, the optical film of Example 2 was obtained using the same materials and processes.

[0131] Photopolymerizable compounds: 70 parts by weight of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry). 30 parts by weight of a mixture of glycerol diacrylate and glycerol triacrylate (M-920, manufactured by Toa Synthetic). (Example 3) Except for changing the photopolymerizable compound to the following substances compared to Example 1, the optical film of Example 3 was obtained using the same materials and processes.

[0132] Photopolymerizable compounds: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry), 40 parts by weight 60 parts by weight of a mixture of glycerol diacrylate and glycerol triacrylate (M-920, manufactured by Toa Synthetic). (Example 4) Except for the addition of the following materials to the resin coating liquid compared to Example 1, the optical film of Example 4 was obtained by using the same materials and processes.

[0133] • Organic microparticles (SSX-2035, made by Techpolymer) 6.0 parts by weight (Example 5) Except for the addition of the following materials to the resin coating liquid compared to Example 3, the optical film of Example 5 was obtained by using the same materials and processes.

[0134] • Organic microparticles (SSX-2035, made by Techpolymer) 6.0 parts by weight (Example 6) Except for changing the photopolymerizable compound to the following substances compared to Example 1, the optical film of Example 6 was obtained using the same materials and processes.

[0135] Photopolymerizable compounds: 100 parts by weight of a mixture of glycerol diacrylate and glycerol triacrylate (M-920, manufactured by Toa Synthetic). (Example 7) Except for changing the amount of functional component added to the resin coating liquid to 20.0 parts by weight compared to Example 1, and not adding the additive as a leveling agent to the resin coating liquid, the optical film of Example 7 was obtained by using the same materials and processes.

[0136] (Example 8) Except for changing the functional components to the following substances relative to Example 1, and not adding the additive as a leveling agent to the resin coating liquid, the optical film of Example 8 was obtained by using the same materials and processes.

[0137] • Functional ingredient: Quaternary ammonium salt-based antibacterial and antiviral agent (silane coupling agent) (POLON-V8, manufactured by Shin-Etsu Chemical Industry) 30.0 parts by weight (Example 9) Except that no additives as leveling agents were added to the resin coating liquid as in Example 1, the optical film of Example 9 was obtained using the same materials and processes.

[0138] (Example 10) Except for changing the functional components to the following substances relative to Example 1 and not adding the additive as a leveling agent to the resin coating liquid, the optical film of Example 10 was obtained by using the same materials and processes.

[0139] • Functional ingredient: Quaternary ammonium salt-based antibacterial and antiviral agent (silane coupling agent) (POLON-V8, manufactured by Shin-Etsu Chemical Industry) 10.0 parts by weight (Comparative Example 1) Except for changing the photopolymerizable compound to the following substances compared to Example 1, and not adding the additive as a leveling agent to the resin coating liquid, the optical film of Comparative Example 1 was obtained using the same materials and processes.

[0140] Photopolymerizable compounds: Dipentaerythritol polyacrylate (NK Ester A-DPH, manufactured by Shin-Nakamura Chemical Industry) 100 parts by weight (Comparative Example 2) Except for changing the photopolymerizable compound to the following substance relative to Example 1, the optical film of Comparative Example 2 was obtained using the same materials and processes.

[0141] Photopolymerizable compounds: 32 parts by weight of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Viscoat #300, manufactured by Osaka Organic Chemical Industry). Dipentaerythritol polyacrylate (NK Ester A-DPH, manufactured by Shin-Nakamura Chemical Industry) 68 parts by weight (Comparative Example 3) Except for the addition of the following materials to the resin coating liquid compared to Comparative Example 2, the optical film of Comparative Example 3 was obtained by using the same materials and processes.

[0142] • Organic microparticles (SSX-2035, made by Techpolymer) 6.0 parts by weight (Comparative Example 4) Except for changing the functional component to the following substances relative to Example 1, the optical film of Comparative Example 4 was obtained using the same materials and processes.

[0143] • Functional ingredient: Silver-based antibacterial and antiviral agent (PTC-NT ANV additive ST, manufactured by Daihatsu Seika Co., Ltd.) 5.0 parts by weight (Comparative Example 5) Except for changing the amount of functional component added to the resin coating liquid to 50.0 parts by mass compared to Example 1, the optical film of Comparative Example 5 was obtained using the same materials and processes.

[0144] (Evaluation Method) <Water vapor transmission> According to JIS Z0208 (Test method for moisture permeability of moisture-proof packaging materials (cup method)), the water vapor transmittance of the optical films and substrates of each embodiment 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 embodiments, the water vapor transmittance Wx per unit film thickness in the resin layer of each embodiment and comparative example was calculated.

[0145] <Pencil Hardness> For the optical films of each embodiment and comparative example, according to JIS K5600-5-4, a hardness test was conducted using a pencil (uni, Mitsubishi Pencil) and a Clemens type scratch hardness tester (HA-301, TESTER Sangyo) under the conditions of a load of 750g and a scratching speed of 0.5mm / sec, thereby determining the pencil hardness of the optical film surface. During the test, the hardness of the pencil was changed while the test was repeated, and the surface of the optical film was visually observed. The highest hardness at which no damage was observed was taken as the measurement result.

[0146] <Haze> The haze was measured on the optical films of each embodiment and each comparative example. The haze was measured using a haze meter (NDH7000, manufactured by Nippon Denshoku Kogyo) according to JIS K7136.

[0147] <Exudation> For each embodiment and comparative example, the surface of the optical film was wiped with nonwoven fabric (BEMCOT M-3II, manufactured by Asahi Kasei), and the surface condition was observed. As an evaluation of the presence or absence of exudation, a condition in which there was no change in the appearance of the surface before and after wiping was defined as good "S", and a condition in which the appearance of the surface changed in terms of haze or wiping marks was defined as bad "F".

[0148] Anti-glare For the optical films of each embodiment and comparative example, anti-glare performance was evaluated by measuring reflective sharpness at 1° and 5°. Each reflective sharpness was measured using a display measurement system (DM&S: SMS-1000) under the conditions described below, with the optical film backed onto a blackboard using optical adhesive as the object. Furthermore, measurements were performed according to ASTM D5767, except for the conditions described below.

[0149] • Width of the slit for the light source: 1mm • Objective lens: 16mm • Distance between the surface of the optical film and the receiving camera: 300mm In the evaluation of anti-glare properties, a situation where the reflection clarity at 1° is 90 or less and the reflection clarity at 5° is 60 or more is defined as good "S", and a situation where at least one of the reflection clarity at 1° is greater than 90 and the reflection clarity at 5° is less than 60 is defined as poor "F". Poor includes a situation equivalent to a state where the surrounding image is clearly reflected on the optical film and a situation equivalent to a state where the image reflected on the optical film is too blurred.

[0150] <XPS analysis> For Examples 1, 7 to 10 and Comparative Example 5, elemental analysis based on 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.

[0151] X-ray source: Monochromatic Al-Kα rays X-ray output power: 25W 15kV Photoelectron reception angle: 45° <EDX analysis> For Examples 1, 7 to 10 and Comparative Example 5, elemental analysis based on EDX was performed on the surface of the optical film using a scanning electron microscope-energy dispersive X-ray analyzer (SU-8020, manufactured by Hitachi High-Technologies).

[0152] <Ion chromatography analysis> For Examples 1, 7 to 10 and Comparative Example 5, a chloride ion quantification based on ion chromatography was performed on the eluate from the surface of the optical film using an ion chromatography analyzer (DX-500, manufactured by Dionex). An anion exchange column (manufactured by Dionex, stationary phase: Ion Pac AS11-HC-4μm) was used for the column, and a KOH solution was used for the eluent. The above-mentioned eluate, that is, the sample used in the measurement of the chloride ion elution amount, was obtained in the order of (a) to (c) described in the above-mentioned embodiment.

[0153] <Antibacterial property> For the optical films of each example and each comparative example, antibacterial tests against Staphylococcus aureus and Escherichia coli were respectively performed in accordance with JIS Z 2801. As an unprocessed sample, a film obtained by omitting the functional component from the target example or comparative example was used. In the evaluation of antibacterial properties, a situation where the antibacterial activity values are both 2.0 or more for both Staphylococcus aureus and Escherichia coli is defined as good "S", and a situation where the antibacterial activity value is less than 2.0 for at least one of Staphylococcus aureus and Escherichia coli is defined as poor "F".

[0154] <Antiviral property> For the optical films of each embodiment and comparative example, antiviral tests against influenza A virus and feline calicivirus were performed according to ISO 21702. As unprocessed samples, films from the intended embodiments or comparative examples, with functional components omitted, were used. In the evaluation of antiviral activity, a value of 2.0 or higher against at least one of influenza A virus and feline calicivirus was designated as "Good" (S), and a value of less than 2.0 against both influenza A virus and feline calicivirus was designated as "Poor" (F).

[0155] (Evaluation Results) Table 1 shows the average hydroxyl value Hv (mgKOH / g) of the resin component in the resin layer and the water vapor permeability Wx (g / m²) per unit film thickness of the resin layer for each embodiment and comparative example. 2 The evaluation items included: (day / μm), composition ratio Rc, type and amount of functional ingredients, presence or absence of light-scattering particles, and results for each evaluation item. The average hydroxyl value Hv was calculated from the hydroxyl value of the monomers in the material. The composition ratio Rc was calculated from the mole fraction of the monomers in the material. The evaluation items were pencil hardness, haze (%), presence or absence of exudation, anti-glare properties, antibacterial properties, and antiviral properties. The evaluation of anti-glare properties was performed on Examples 4 and 5 and Comparative Example 3, which contained light-scattering particles to demonstrate anti-glare properties. In addition, for Examples 7, 8, 10 and Comparative Example 5, some items were not evaluated.

[0156] In addition, Table 2 shows the results of elemental analysis based on XPS, EDX, and ion chromatography (IC), respectively. Furthermore, Table 2 again shows the evaluation results of antibacterial and antiviral properties.

[0157] As shown in Table 1, in Examples 1-10 where the average hydroxyl value (Hv) of the resin component was 100 mg KOH / g or higher, exudation was suppressed even when the functional component was organic. On the other hand, in Comparative Examples 1-3 where the average hydroxyl value (Hv) of the resin component was less than 100 mg KOH / g and the functional component was organic, exudation occurred. Furthermore, in Comparative Example 5 where the amount of functional component added was 50% by mass of the resin component, exudation also occurred.

[0158] Furthermore, in the case of examples 1-3 and 6-10 where the functional component is an organic system, the haze was suppressed to less than 1%, while in comparative example 4 where the functional component is a silver particle system, the haze exceeded 3%.

[0159] Table 1 confirms that the water vapor permeability Wx per unit film thickness of the resin layer is correlated with the average hydroxyl value Hv of the resin components. In Examples 1-10 where exudation was suppressed, the water vapor permeability Wx was 170 (g / m³). 2 •day) / μm or higher. On the other hand, in Comparative Examples 1-3 where efflorescence occurred, the water vapor permeability Wx was less than 170 (g / m²). 2 ·day) / μm.

[0160] As confirmed above, by using organic functional components and resin components with an average hydroxyl value (Hv) of 100 mg KOH / g or higher, at least antibacterial properties can be obtained, and the reduction of optical properties and exudation can be inhibited.

[0161] It was also confirmed that, through the use of organic functional components, the water vapor permeability Wx in the resin layer was 170 (g / m²). 2 With a thickness of ·day) / μm or higher, antibacterial properties can be obtained at least, and the reduction of optical properties and exudation can be inhibited.

[0162] Furthermore, in Example 6, where the average hydroxyl value Hv of the resin component exceeded 200 mg KOH / g, the pencil hardness was lower compared to other examples. Therefore, to suppress the decrease in mechanical properties, the average hydroxyl value Hv of the resin component is preferably below 200 mg KOH / g. Similarly, according to Example 6, to suppress the decrease in mechanical properties, the water vapor permeability Wx is preferably 450 (g / m²). 2 Below ·day) / μm.

[0163] Furthermore, from the perspective of composition ratio Rc, it is confirmed that if the composition ratio Rc is above 0.40, exudation can be appropriately suppressed, and if the composition ratio Rc is below 0.85, good hardness can be obtained.

[0164] As shown in Table 2, in Examples 1, 7, and 8, which exhibited good antibacterial and antiviral properties, the elemental concentration of N was 0.80 atomic% or higher, the elemental concentration of Si was 0.75 atomic% or higher, and the elemental concentration of Cl was 0.35 atomic% or higher, according to XPS-based elemental analysis. On the other hand, in Examples 9 and 10, where at least one of these elemental concentrations was below the aforementioned range, antibacterial properties were obtained, but antiviral properties were insufficient.

[0165] Furthermore, in Examples 1, 7, and 8, the elemental concentration of Si was 0.20 atomic% or more, and the elemental concentration of Cl was 0.19 atomic% or more, in EDX-based elemental analysis. On the other hand, in Examples 9 and 10, these elemental concentrations were lower than the above ranges.

[0166] Furthermore, in Examples 1, 7, and 8, the dissolution rate of Cl in elemental analysis based on ion chromatography was 4.0 nmol / cm³. 2 That's all. On the other hand, in Examples 9 and 10, the amount of Cl dissolved was lower than the above range.

[0167] Therefore, it was confirmed that the results of elemental analysis were within the above range, which allowed for the good acquisition of both antibacterial and antiviral properties.

[0168] Furthermore, in Examples 1, 7, and 8, the elemental concentration of N was 4.00 atomic% or less, the elemental concentration of Si was 4.50 atomic% or less, and the elemental concentration of Cl was 2.90 atomic% or less in Comparative Example 5, where the elemental concentrations exceeded the above ranges, leaching occurred.

[0169] Furthermore, in Examples 1, 7, and 8, the elemental concentration of Si was 1.30 atomic% or less, and the elemental concentration of Cl was 1.40 atomic% or less, in EDX-based elemental analysis. On the other hand, in Comparative Example 5, these elemental concentrations were higher than the above ranges.

[0170] Furthermore, in Examples 1, 7, and 8, the dissolution rate of Cl in elemental analysis based on ion chromatography was 55.0 nmol / cm³. 2 Below. On the other hand, in Comparative Example 5, the amount of Cl dissolved exceeded the above range.

[0171] Therefore, it was confirmed that the results of elemental analysis were within the above range, which could suppress the leakage of functional components caused by excess.

[0172] Based on the above implementation methods and embodiments, the following effects can be obtained.

[0173] (1) The functional layer contains organic functional components and resin components with an average hydroxyl value (Hv) of 100 mg KOH / g or higher. As a result, at least one of antibacterial and antiviral properties can be obtained, and the increase of fog and the occurrence of exudation can be inhibited.

[0174] (2) The functional layer contains organic functional components and resin components, and the water vapor permeability per unit thickness of the functional layer is 170 (g / m). 2 •day) / μm or higher. Thus, at least one of antibacterial and antiviral properties can be obtained, and the increase in fog density and the occurrence of exudation can be inhibited.

[0175] (3) By making the average hydroxyl value of the resin components below 200 mg KOH / g, the reduction of mechanical properties in the functional layer can be suppressed.

[0176] (4) By making the resin composition ratio Rc 0.40 or higher, exudation can be appropriately suppressed. In addition, by making the resin composition ratio Rc 0.85 or lower, the reduction of mechanical properties can be appropriately suppressed.

[0177] (5) If the haze of the optical film is less than 3%, high transparency can be obtained. Moreover, by using organic components as functional ingredients, it is easy to make the haze less than 3%.

[0178] (6) If the optical film is composed of microparticles for light scattering, an anti-glare optical film can be achieved. Moreover, if the haze of the optical film is 5% or more and 35% or less, good anti-glare performance can be obtained. In addition, if the reflectivity of the optical film at 1° is 90 or less and the reflectivity at 5° is 60 or more, good anti-glare performance can be obtained.

[0179] (7) If the average particle size of the particles used for light scattering is more than 30% of the thickness of the resin layer, the light scattering effect caused by the particles can be appropriately obtained.

[0180] (8) If the content of light-scattering particles in the resin layer is 3.0% by mass or more and 20% by mass or less, the light scattering effect caused by the particles can be appropriately obtained, and the reduction of the mechanical properties of the resin layer can be suppressed.

[0181] (9) If the pencil hardness of the surface of the optical film is above 2H, good mechanical properties can be obtained.

[0182] (10) If the thickness of the resin layer is 1.0 μm or more, it can improve the uniformity of the resin layer thickness, the coatability of the coating liquid used to form the resin layer, the mechanical strength of the resin layer, and the antibacterial and antiviral activities when the resin layer is a functional layer.

[0183] (11) If the thickness of the low refractive index layer is above 30 nm and below 300 nm, it is easy to generate light interference and to obtain good scratch resistance and adhesion to the resin layer.

[0184] (12) If the functional component is a silane coupling agent containing quaternary ammonium salt in its molecular structure, it is suitable as a functional component of an organic system.

[0185] (13) In the elemental analysis of the surface of the optical film using XPS, the elemental concentration of N is 0.80 atomic% or more and 4.00 atomic% or less, the elemental concentration of Si is 0.75 atomic% or more and 4.50 atomic% or less, and the elemental concentration of halogens is 0.35 atomic% or more and 2.90 atomic% or less. With this configuration, both antibacterial and antiviral properties can be obtained well, and on the other hand, exudation in the functional layer can be suppressed.

[0186] (14) In the elemental analysis of the surface of the optical film using EDX, the elemental concentration of Si is 0.20 atomic% or more and 1.30 atomic% or less, and the elemental concentration of halogens is 0.19 atomic% or more and 1.40 atomic% or less. With this composition, both antibacterial and antiviral properties can be obtained well, and on the other hand, exudation in the functional layer can be suppressed.

[0187] (15) The halogen leaching amount from the surface of the optical film, determined by ion chromatography, is 4.0 nmol / cm. 2 Above and 55.0 nmol / cm 2 The following is an explanation of the advantages of this structure: it provides both antibacterial and antiviral properties, while also inhibiting exudation in the functional layer.

[0188] (16) By incorporating an optical film into the display device, antibacterial and antiviral properties can be obtained near the surface of the display device, as well as good optical and mechanical properties. In particular, if the display device is equipped with a touch panel, the benefits of the antibacterial and antiviral properties of the optical film can be enhanced.

[0189] Furthermore, the expression "at least one" as used in this specification means "more than one" of the desired options. For example, if the number of options is two, "at least one" as used in this specification means "only one option" or "both of the two options." As another example, if the number of options is three or more, "at least one" as used in this specification means "only one option" or "any combination of two or more options."

[0190] Explanation of reference numerals in the attached figures 10, 10A, 10B optical films 20 Substrate 21 Resin Layer 22 Low-refractive-index layer 100 display devices

Claims

1. An optical film comprising a substrate and a functional layer, said functional layer comprising a functional component as at least one of an antibacterial agent and an antiviral agent, and a resin component, wherein, The functional component is an organic material. The proportion of the functional component relative to the resin component contained in the functional layer is less than 40% by mass. The optical film satisfies at least one of the following first condition and the following second condition: The first condition is that the average hydroxyl value of the resin components is ≥100 mg KOH / g. The second condition is that the water vapor permeability per unit membrane thickness in the functional layer is 170 (g / m²). 2 ·days / μm or more.

2. The optical film according to claim 1, wherein it satisfies the first condition, and the average hydroxyl value of the resin component is below 200 mg KOH / g.

3. The optical film according to claim 1, wherein, The polymer structural units contained in the resin component include a first structural unit without hydroxyl groups and a second structural unit having one or more hydroxyl groups. The ratio of the second structural unit to all structural units in the resin component is 0.40 or higher.

4. The optical film according to claim 1, wherein, The haze of the optical film is below 3%.

5. The optical film according to claim 1, wherein, The optical film has a resin layer supported by the substrate. The functional layer includes the resin layer. The resin layer contains microparticles for light scattering.

6. The optical film according to claim 5, wherein, The average particle size of the microparticles is more than 30% of the thickness of the resin layer.

7. The optical film according to claim 5, wherein, The proportion of the microparticles 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, wherein, The surface of the optical film has a pencil hardness of 2H or higher.

9. The optical film according to claim 1, wherein, The haze of the optical film is above 5% and below 35%.

10. The optical film according to claim 1, wherein, The optical film has a reflection resolution of less than 90 at 1° and a reflection resolution of more than 60 at 5°.

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

12. The optical film according to claim 1, wherein, The optical film comprises: The resin layer supported by the substrate; and A low-refractive-index layer, having a lower refractive index than the resin layer, covers the resin layer on the side opposite to the substrate. The functional layer comprises at least one of the resin layer and the low refractive index layer. The thickness of the low-refractive-index layer is greater than 30 nm and less than 300 nm.

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

14. The optical film according to claim 13, wherein, The optical film has a first surface and a second surface that is the opposite side of the first surface and is a surface of the substrate. In the elemental analysis of the first surface using X-ray photoelectron spectroscopy, the elemental concentration of N is 0.80 atomic% or more and 4.00 atomic% or less, the elemental concentration of Si is 0.75 atomic% or more and 4.50 atomic% or less, and the elemental concentration of halogens is 0.35 atomic% or more and 2.90 atomic% or less.

15. The optical film according to claim 13, wherein, The optical film has a first surface and a second surface that is the opposite side of the first surface and is a surface of the substrate. In the elemental analysis of the first surface using energy-dispersive X-ray spectrometry, the elemental concentration of Si is 0.20 atomic% or more and 1.30 atomic% or less, and the elemental concentration of halogens is 0.19 atomic% or more and 1.40 atomic% or less.

16. The optical film according to claim 13, wherein, The optical film has a first surface and a second surface that is the opposite side of the first surface and is a surface of the substrate. The leaching amount of halogen elements from the first surface, determined by ion chromatography, was 4.0 nmol / cm. 2 Above and 55.0 nmol / cm 2 the following.

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

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