Optical laminate, polarizing plate obtained using said optical laminate, surface sheet, panel, image display device, and method for selecting optical laminate

Abstract

Provided is an optical laminate which lowers the burden on the environment and exhibits excellent scratch resistance. This optical laminate has at least one functional layer on a base material. The optical laminate contains at least one type of solvent selected from among toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate and propylene glycol monomethyl ether acetate. The total concentration of these solvents in the optical laminate, as determined by gas chromatography quantitative analysis, is 15.00 mg / m2 or less.

Description

Optical laminate, polarizing plate, surface plate, panel and image display device using said optical laminate, and method for selecting an optical laminate

[0001] The present disclosure relates to an optical laminate, a polarizing plate, a faceplate, a panel, and an image display device using the optical laminate, and a method for selecting an optical laminate.

[0002] An optical laminate may be installed in an image display device such as a monitor of a television, a notebook PC, or a desktop PC. For example, an optical laminate may be installed on the surface of the image display device in order to suppress reflection of lighting, people, or other background objects, or to suppress surface reflection. Examples of optical laminates proposed include Patent Documents 1 and 2.

[0003] JP 2022-46652 A JP 2023-75138 A

[0004] In recent years, in order to aim for a sustainable recycling-based society, there has been a demand for optical laminates that reduce the burden on the environment. On the other hand, in order to prevent the visibility of image display devices from being impaired, optical laminates are required to have excellent scratch resistance. However, the optical laminates of Patent Documents 1 and 2 do not consider at all how to achieve both a reduced burden on the environment and excellent scratch resistance.

[0005] An object of the present disclosure is to provide an optical laminate that reduces the burden on the environment and has excellent scratch resistance.An object of the present disclosure is to provide a polarizing plate, a faceplate, a panel, and an image display device that reduce the burden on the environment and have excellent scratch resistance.An object of the present disclosure is to provide a method for efficiently selecting an optical laminate that reduces the burden on the environment and has excellent scratch resistance.

[0006] The present disclosure provides the following (1) to (6): (1) An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, wherein the total concentration of the solvents in the optical laminate is 15.00 mg / m or less as determined by gas chromatography quantitative analysis. ２ An optical laminate, which is the following: (2) A polarizing plate having a polarizer, a first transparent protective plate arranged on one side of the polarizer, and a second transparent protective plate arranged on the other side of the polarizer, wherein at least one of the first transparent protective plate and the second transparent protective plate is the optical laminate described in (1). (3) A faceplate for an image display device, which has a protective film laminated on a resin plate or a glass plate, wherein the protective film is the optical laminate described in (1). (4) A panel having a display element and an optical laminate arranged on the light exit surface side of the display element, wherein the optical laminate comprises the optical laminate described in (1). (5) An image display device, which includes the panel described in (4). (6) A method for selecting an optical laminate, which selects an optical laminate that satisfies the following selection conditions: (Selection Conditions for Optical Laminate) An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and a total concentration of the solvents in the optical laminate determined by gas chromatography quantitative analysis is 15.00 mg / m ２ The following is the result.

[0007] The optical laminate, polarizing plate, faceplate, panel, and image display device of the present disclosure can reduce the burden on the environment and improve scratch resistance. The method for selecting an optical laminate of the present disclosure can efficiently select an optical laminate that reduces the burden on the environment and has good scratch resistance.

[0008] 1 is a schematic cross-sectional view showing an embodiment of an optical laminate of the present disclosure. 2 is a cross-sectional view showing an embodiment of a panel of the present disclosure.

[0009] Hereinafter, embodiments of the present disclosure will be described. [Optical Laminate] The optical laminate of the present disclosure is as follows: An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and a total concentration of the solvents in the optical laminate measured by gas chromatography quantitative analysis is 15.00 mg / m ２ The optical laminate is as follows:

[0010] Fig. 1 is a schematic cross-sectional view of the cross-sectional shape of an optical laminate 100 of the present disclosure. The optical laminate 100 of Fig. 1 has a functional layer 20 on a substrate 10. The optical laminate 100 of Fig. 1 has a first functional layer 21 and a second functional layer 22 as the functional layer 20. Fig. 1 is a schematic cross-sectional view. In other words, the scale of each layer constituting the optical laminate 100 is schematic for ease of illustration and differs from the actual scale. The same is true for Fig. 2.

[0011] The optical laminate of the present disclosure is not limited to the laminate configuration of Fig. 1. For example, the optical laminate of the present disclosure may have only one layer as a functional layer, or may have three or more layers as functional layers. Furthermore, the optical laminate of the present disclosure may have functional layers on both surfaces of the substrate.

[0012] <Substrate> The substrate is preferably one that has optical transparency, smoothness, heat resistance, and excellent mechanical strength. Examples of such substrates include plastic films such as polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyethersulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polyurethane, and amorphous olefin (Cyclo-Olefin-Polymer: COP). The substrate may also be one in which two or more plastic films are bonded together.

[0013] Among plastic films, stretched polyester films are preferred for their mechanical strength and dimensional stability, and biaxially stretched polyester films are more preferred. Examples of polyester films include polyethylene terephthalate films and polyethylene naphthalate films. Among plastic films, TAC films (triacetylcellulose films) and acrylic films are preferred because they easily provide good light transmittance and optical isotropy. TAC films and acrylic films are also preferred because they facilitate the formation of a permeation layer, which will be described later. Among plastic films, COP films and polyester films are preferred because they have excellent weather resistance.

[0014] The raw material of the plastic film may be one or more selected from "newly synthesized raw materials", "recycled raw materials" and "biomass-derived raw materials". In order to reduce the burden on the environment, it is preferable that the raw material of the plastic film contains biomass-derived raw materials. Biomass-derived raw materials are raw materials derived from plants. Whether a raw material is biomass-derived or not can be determined by radiocarbon ( １４ Carbon dioxide in the atmosphere contains: １４ Since carbon dioxide is contained in the atmosphere at a certain rate (105.5 pMC), the carbon dioxide in plants that grow １４The carbon content is also known to be about 105.5 pMC. １４ It is also known that carbon is hardly contained. Therefore, the carbon atoms contained in the raw material are １４ Whether or not the raw material is biomass-derived can be determined by measuring the proportion of C. In order to improve mechanical strength and dimensional stability and reduce the burden on the environment, the substrate is preferably a polyester film containing polyester made from biomass-derived raw materials.

[0015] The thickness of the substrate is preferably 5.0 μm or more and 300.0 μm or less, more preferably 20.0 μm or more and 200.0 μm or less, and even more preferably 30.0 μm or more and 120.0 μm or less. When it is desired to thin the optical laminate, the upper limit of the substrate thickness is preferably 100 μm or less, more preferably 80.0 μm or less. Furthermore, when the substrate is a low-moisture-permeable substrate such as polyester, COP, or acrylic, the upper limit of the substrate thickness for thinning is preferably 60.0 μm or less, more preferably 40.0 μm or less. Even in the case of a large screen, as long as the upper limit of the substrate thickness is within the above-mentioned range, it is also preferable in that distortion can be made less likely to occur. In this specification, the thickness of the substrate is measured using a general-purpose film thickness measuring device. The thickness of the substrate may be the above-mentioned value as the average value measured at any 10 points.

[0016] In this specification, various measurements such as layer thickness are taken in an atmosphere at a temperature of 23±1° C. and a relative humidity of 40% to 65%, unless otherwise specified.

[0017] The substrate preferably has a permeation layer on the surface having the functional layer. The presence of the permeation layer can facilitate improving adhesion between the substrate and the functional layer. Furthermore, the presence of the permeation layer can facilitate suppressing the occurrence of interference fringes when multiple optical laminates are stacked, and when the optical laminate is stacked with another light-transmitting member. The permeation layer is preferably a permeation layer containing the solvent. The solvent is at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate.

[0018] The thickness of the penetration layer is preferably 5.0 μm or less, more preferably 3.0 μm or less, and even more preferably 1.5 μm or less. If the thickness of the penetration layer is too thick, a large amount of the substrate components may flow into the functional layer, which may reduce the scratch resistance and pencil hardness of the optical laminate. Therefore, by setting the thickness of the penetration layer to 5.0 μm or less, it is possible to easily suppress the reduction in scratch resistance of the optical laminate. Examples of substrate components include resins, plasticizers, and ultraviolet absorbers. Plasticizers and ultraviolet absorbers tend to reduce the scratch resistance of the optical laminate. In order to facilitate good adhesion between the substrate and the functional layer, the thickness of the penetration layer is preferably 0.05 μm or more, more preferably 0.3 μm or more, and even more preferably 0.5 μm or more.

[0019] In the configuration requirements described herein, when multiple upper limit and lower limit options are shown, it is assumed that the range described is a combination of one selected from the upper limit options and one selected from the lower limit options. For example, embodiments of the above-mentioned penetration layer thickness ranges include 0.05 μm to 5.0 μm, 0.05 μm to 3.0 μm, 0.05 μm to 1.5 μm, 0.3 μm to 5.0 μm, 0.3 μm to 3.0 μm, 0.3 μm to 1.5 μm, 0.5 μm to 5.0 μm, 0.5 μm to 3.0 μm, and 0.5 μm to 1.5 μm.

[0020] When the ratio of the thickness of the penetration layer to the thickness of the substrate is defined as the "thickness ratio of the penetration layer," the thickness ratio of the penetration layer is preferably within the following range. When the thickness of the substrate is 5.0 μm or more and less than 20 μm, the thickness ratio of the penetration layer is preferably 0.0025 or more and 0.4000 or less. When the thickness of the substrate is 20 μm or more and less than 100 μm, the thickness ratio of the penetration layer is preferably 0.0005 or more and 0.2500 or less. When the thickness of the substrate is 100 μm or more and 300 μm or less, the thickness ratio of the penetration layer is preferably 0.000167 or more and 0.050000 or less. By setting the ratio to a predetermined value or more, it is possible to easily improve the adhesion between the substrate and the functional layer. By setting the ratio to a predetermined value or less, it is possible to easily suppress a decrease in the strength of the substrate and to easily suppress a decrease in the scratch resistance of the optical laminate.

[0021] The thickness of the permeation layer is measured by STEM (scanning transmission electron microscope) using a measurement sample in which the cross section of the optical laminate is exposed. Twenty arbitrary points are selected from the STEM cross-sectional photograph of the sample, and the average value of the 20 points is taken as the thickness of the permeation layer of the optical laminate of the present disclosure. The sample can be prepared, for example, by the following steps (A1) to (A2). If the permeation layer is difficult to distinguish due to insufficient contrast, the sample may be stained with a stain such as osmium tetroxide, ruthenium tetroxide, or phosphotungstic acid.

[0022] (A1) The optical laminate is cut to a desired size to prepare a cut sample, and then the cut sample is embedded in resin to prepare an embedded sample. The cut sample is a strip measuring 10 mm long x 3 mm wide. The embedding resin is epoxy resin. The embedded sample is obtained by placing the cut sample in a silicon embedding plate, pouring in the embedding resin, hardening the embedding resin, and then removing the cut sample and the embedding resin encasing it from the silicon embedding plate. The embedded sample is in the shape of a block. (A2) The block-shaped embedded sample is cut with a diamond knife to prepare a slice sample. As described above, slices cut from the block-shaped embedded sample that are free of defects such as holes and have a uniform thickness of 60 nm to 100 nm are used as measurement samples.

[0023] The substrate preferably has a total light transmittance of 70% or more, more preferably 80% or more, and even more preferably 85% or more according to JIS K7361-1:1997.The substrate preferably has a haze of 10% or less, more preferably 5% or less, and even more preferably 3% or less according to JIS K7136:2000.

[0024] The surface of the substrate may be subjected to a physical treatment such as corona discharge treatment or a chemical treatment to improve adhesion. The substrate may also have an easy-adhesion layer on its surface.

[0025] <Functional Layer> The optical laminate of the present disclosure has at least one or more functional layers on a substrate. The optical laminate of the present disclosure preferably includes one or more layers selected from a hard coat layer, an antiglare layer, an antireflection layer, an antifouling layer, an antistatic layer, and a conductive layer as the functional layer. The optical laminate of the present disclosure more preferably includes an antiglare layer as the functional layer.

[0026] The following (1) to (18) are embodiments of the layer structure of the optical laminate of the present disclosure. In the following (1) to (18), " / " indicates the interface of the layers. (1) Substrate / hard coat layer (2) Substrate / antiglare layer (3) Substrate / hard coat layer / antireflection layer (4) Substrate / antiglare layer / antireflection layer (5) Substrate / hard coat layer / antifouling layer (6) Substrate / antiglare layer / antifouling layer (7) Conductive layer / substrate / hard coat layer (8) Conductive layer / substrate / antiglare layer (9) Antistatic layer / substrate / hard coat layer (10) Antistatic layer / substrate / antiglare layer (11) Conductive layer / substrate / hard coat layer / antireflection layer (12) Conductive layer / substrate / antiglare layer / antireflection layer (13) Antistatic layer / substrate / hard coat layer / antireflection layer (14) Antistatic layer / substrate / antiglare layer / antireflection layer (15) Conductive layer / substrate / hard coat layer / antifouling layer (16) Conductive layer / substrate / antiglare layer / antifouling layer (17) Antistatic layer / substrate / hard coat layer / antifouling layer (18) Antistatic layer / substrate / antiglare layer / antifouling layer

[0027] The total thickness of the functional layers is preferably 20.0 μm or less, more preferably 15.0 μm or less, and even more preferably 10.0 μm or less. By setting the total thickness of the functional layers to 20.0 μm or less, the total concentration of the solvent in the optical laminate can be reduced to 15.00 mg / m ２ If the total thickness of the functional layers is too thin, it becomes difficult to impart scratch resistance to the optical laminate. Therefore, the total thickness of the functional layers is preferably 1.0 μm or more, more preferably 3.0 μm or more, and even more preferably 5.0 μm or more.

[0028] In this specification, the thickness of the functional layer is measured by STEM (scanning transmission electron microscope) using a measurement sample in which the cross section of the optical laminate is exposed. 20 points are arbitrarily selected from the STEM cross-sectional photograph of the sample, and the average value of the 20 points is defined as the thickness of the functional layer of the optical laminate of the present disclosure.

[0029] The functional layer includes, for example, a binder component and an additive.

[0030] The binder component is preferably a resin. That is, the binder component is preferably a binder resin. In order to facilitate good scratch resistance, the binder resin preferably contains a cured product of a curable resin composition such as a cured product of a thermosetting resin composition or a cured product of an ionizing radiation curable resin composition, and more preferably contains a cured product of an ionizing radiation curable resin composition. The binder resin may contain a thermoplastic resin within a range that does not impair the effects of the present disclosure.

[0031] The ratio of the cured product of the curable resin composition to the total amount of the binder resin is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass, in order to facilitate good scratch resistance.

[0032] A thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that cures when heated. Examples of thermosetting resins include acrylic resins, urethane resins, phenolic resins, urea-melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. In a thermosetting resin composition, a curing agent is added to the curable resin as needed.

[0033] The ionizing radiation-curable resin composition is a composition containing a compound having an ionizing radiation-curable functional group (hereinafter also referred to as "ionizing radiation-curable compound"). Examples of the ionizing radiation-curable functional group include ethylenically unsaturated bond groups such as (meth)acryloyl groups, vinyl groups, and allyl groups, as well as epoxy groups and oxetanyl groups. The ionizing radiation-curable compound is preferably a compound having an ethylenically unsaturated bond group, more preferably a compound having two or more ethylenically unsaturated bond groups, and even more preferably a polyfunctional (meth)acrylate compound having two or more ethylenically unsaturated bond groups. Both monomers and oligomers can be used as the polyfunctional (meth)acrylate compound. Ionizing radiation refers to electromagnetic waves or charged particle beams that have an energy quantum capable of polymerizing or crosslinking molecules. Typically, ultraviolet (UV) or electron beams (EB) are used. Other types of radiation that can be used include electromagnetic waves such as X-rays and gamma rays, and charged particle beams such as alpha rays and ion beams.

[0034] Among the polyfunctional (meth)acrylate compounds, examples of bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxydiacrylate, bisphenol A tetrapropoxydiacrylate, 1,6-hexanediol diacrylate, etc. Examples of trifunctional or higher functional (meth)acrylate monomers include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol tetra(meth)acrylate, isocyanuric acid-modified tri(meth)acrylate, etc. The above (meth)acrylate monomers may have a partially modified molecular skeleton. For example, the (meth)acrylate monomers may be used in which a part of the molecular skeleton is modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol, or the like.

[0035] Examples of polyfunctional (meth)acrylate oligomers include acrylate polymers such as urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate. Urethane (meth)acrylate can be obtained, for example, by reacting a polyhydric alcohol and an organic diisocyanate with a hydroxy (meth)acrylate. Preferred epoxy (meth)acrylates include (meth)acrylates obtained by reacting a trifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with (meth)acrylic acid, (meth)acrylates obtained by reacting a difunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with a polybasic acid and (meth)acrylic acid, and (meth)acrylates obtained by reacting a difunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with a phenol and (meth)acrylic acid.

[0036] The weight average molecular weight of the polyfunctional (meth)acrylate oligomer is preferably from 500 to 3000, and more preferably from 700 to 2500. In this specification, the weight average molecular weight is an average molecular weight measured by GPC analysis and converted into standard polystyrene.

[0037] Furthermore, for the purpose of adjusting the viscosity of the functional layer coating liquid, a monofunctional (meth)acrylate may be used in combination as the ionizing radiation curable compound. Examples of the monofunctional (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and isobornyl (meth)acrylate. The above ionizing radiation curable compounds may be used alone or in combination of two or more.

[0038] When the ionizing radiation-curable compound is an ultraviolet-curable compound, the ionizing radiation-curable resin composition preferably contains additives such as a photopolymerization initiator and a photopolymerization accelerator. Examples of the photopolymerization initiator include one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler's ketone, benzoin, benzyl dimethyl ketal, benzoyl benzoate, α-acyloxime ester, thioxanthones, and the like. The photopolymerization accelerator can reduce polymerization inhibition by air during curing and increase the curing rate. Examples of the accelerator include p-dimethylaminobenzoic acid isoamyl ester and p-dimethylaminobenzoic acid ethyl ester.

[0039] When the binder resin contains a cured product of an ionizing radiation-curable resin composition, the ionizing radiation-curable resin composition may further contain a polyfunctional (meth)acrylate oligomer in addition to the polyfunctional (meth)acrylate monomer. The mass ratio of the polyfunctional (meth)acrylate monomer to the polyfunctional (meth)acrylate oligomer (mass of the polyfunctional (meth)acrylate monomer:mass of the polyfunctional (meth)acrylate oligomer) is preferably 5:95 to 60:40, more preferably 20:80 to 60:40, and even more preferably 40:60 to 60:40. The polyfunctional (meth)acrylate monomer increases the crosslinking density of the coating film and tends to improve scratch resistance. On the other hand, since the polyfunctional (meth)acrylate monomer penetrates into the substrate more easily than the polyfunctional (meth)acrylate oligomer, adding an excess amount may result in an excessively thick penetration layer. Therefore, by using the polyfunctional (meth)acrylate monomer and the polyfunctional (meth)acrylate oligomer in the above mass ratio, it is possible to easily improve the scratch resistance of the optical layered body.

[0040] As described above, the functional layer preferably contains an additive in addition to the binder component. The additive may be selected from general-purpose materials depending on the function of the functional layer. When the functional layer is an antiglare layer, it is preferable to contain particles as an additive. When the functional layer is an antireflection layer, it is preferable to contain high-refractive-index particles or low-refractive-index particles as an additive. The antireflection layer may be a single layer of a low-refractive-index layer or may be multilayered. An example of a multilayer antireflection layer is an antireflection layer consisting of two layers, a high-refractive-index layer and a low-refractive-index layer. When the functional layer is an antifouling layer, it is preferable to contain an antifouling agent as an additive. When the functional layer is an antistatic layer, it is preferable to contain an antistatic agent as an additive. When the functional layer is a conductive layer, it is preferable to contain a conductive agent as an additive.

[0041] Examples of particles contained in the antiglare layer include organic particles and inorganic particles. Examples of inorganic particles include silica, alumina, zirconia, and titania, with silica being preferred. Among inorganic particles, amorphous inorganic particles are preferred, with amorphous silica being more preferred. Examples of organic particles include particles containing one or more resins selected from polymethyl methacrylate, polyacrylic-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, silicone, fluorine-based resin, and polyester-based resin. The average particle size of the particles is preferably 1.0 μm or more and 5.5 μm or less, more preferably 1.3 μm or more and 5.0 μm or less, and even more preferably 1.5 μm or more and 4.5 μm or less. In this specification, the average particle size of the particles refers to the value determined as the volume average value d50 by laser diffraction analysis.

[0042] Examples of low refractive index particles include hollow particles and solid particles. The material of the hollow particles and solid particles may be either an inorganic compound such as silica or magnesium fluoride, or an organic compound, but silica is preferred for its low refractive index and strength. That is, the low refractive index layer preferably contains hollow silica particles. It is also preferred that the low refractive index layer further contains solid silica particles in addition to hollow silica particles. The average primary particle diameter of the hollow particles is preferably smaller than the thickness of the low refractive index layer, for example, 1 nm or more and 150 nm or less. The average primary particle diameter of the solid particles is preferably smaller than the thickness of the low refractive index layer, for example, 0.5 nm or more and 100 nm or less.

[0043] The average primary particle diameters of low-refractive index particles and high-refractive index particles (described later) can be calculated by the following steps (B1) to (B3). (B1) The cross section of the optical laminate is imaged using a TEM or STEM. The accelerating voltage of the TEM or STEM is 10 kV to 30 kV, and the magnification is 50,000 to 300,000 times. (B2) Ten particles are randomly selected from the observed image, and the particle diameter of each particle is calculated. The particle diameter is measured as the distance between two parallel lines that maximize the distance between the cross section of the particle. (B3) The same procedure is performed five times using a separate image of the same sample, and the value obtained from the number average of the particle diameters of a total of 50 particles is regarded as the average primary particle diameter of the particles.

[0044] Examples of high refractive index particles include antimony pentoxide, zinc oxide, titanium oxide, cerium oxide, tin-doped indium oxide, antimony-doped tin oxide, yttrium oxide, zirconium oxide, etc. The average primary particle diameter of the high refractive index particles is preferably smaller than the thickness of the high refractive index layer, and is, for example, 2 nm or more and 200 nm or less.

[0045] - Formation of Functional Layer - The functional layer can be formed, for example, by applying a functional layer coating liquid containing components constituting the functional layer and a solvent to a substrate, etc. After the functional layer coating liquid is applied to the substrate, etc., a drying step may be carried out as necessary.

[0046] Examples of the solvent include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (isopropanol, butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), glycol ethers (propylene glycol monomethyl ether acetate, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), and mixtures thereof may also be used. Among the above solvents, it is preferable to contain at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate.

[0047] The mass ratio of the solvent to the total amount of the functional layer coating liquid is preferably 0.01 mass% or more and 10 mass% or less, more preferably 0.1 mass% or more and 5.0 mass% or less, and even more preferably 0.3 mass% or more and 3.0 mass% or less. By making the solvent ratio 0.1 mass% or more, it is possible to easily improve the adhesion between the substrate and the functional layer. Furthermore, by making the solvent ratio 0.3 mass% or more, it is easy to apply the functional layer coating liquid to the substrate, which makes it easy to improve the physical properties of the functional layer, such as scratch resistance. By making the solvent ratio 10 mass% or less, the total concentration of the solvent in the optical laminate can be reduced to 15.00 mg / m ２ Furthermore, by setting the solvent ratio to 5.0 mass% or less, the amount of solvent discharged into the outside air during the manufacturing process of the optical laminate can be reduced, making it easier to reduce the burden on the environment. Furthermore, by setting the solvent ratio to 3.0 mass% or less, the energy required to dry the functional layer coating liquid can be reduced, making it easier to reduce the burden on the environment.

[0048] Toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone are difficult to volatilize from the functional layer, so they remain in the functional layer for a long time. Therefore, when toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone are contained, they are likely to cause sick house syndrome and deteriorate people's living environment. On the other hand, when toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone are contained, it is easy to form a permeation layer on the substrate. Therefore, the mass ratio of the total amount of toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone to the total amount of solvent in the functional layer coating liquid is preferably 0.01 mass% or more and 5.0 mass% or less, more preferably 0.3 mass% or more and 1.5 mass% or less, and even more preferably 0.5 mass% or more and 1.0 mass% or less.

[0049] When forming a functional layer from a functional layer coating liquid, it is preferable to control drying conditions such as the drying temperature, the air speed in the dryer, and the drying time. A low drying temperature tends to increase the solvent concentration in the optical laminate. A high drying temperature may result in a deterioration of the physical properties of the functional layer. A slow drying air speed tends to increase the solvent concentration in the optical laminate. A fast drying air speed may result in a deterioration of the physical properties of the functional layer. A short drying time tends to increase the solvent concentration in the optical laminate. A long drying temperature may result in a deterioration of the physical properties of the functional layer. Furthermore, a high relative humidity tends to increase the solvent concentration in the optical laminate. For these reasons, the drying temperature is preferably 20°C or higher and 100°C or lower, more preferably 25°C or higher and 90°C or lower. The drying air speed is preferably 0.01 m / s or higher and 50.0 m / s or lower, and more preferably 0.1 m / s or higher and 30.0 m / s or lower. The drying time is preferably 5 seconds or higher and 120 seconds or lower, more preferably 10 seconds or higher and 100 seconds or lower. The relative humidity during the formation of the functional layer is preferably 70% or less, and more preferably 55% or less.

[0050] The optical laminate of the present disclosure contains at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and the total concentration of the solvents in the optical laminate is 15.00 mg / m or less by gas chromatography quantitative analysis. ２ It is required that:

[0051] By including at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate in the optical laminate, the adhesion between the substrate and the functional layer can be improved. The lower the total concentration of solvents in the optical laminate, the lower the solvent content of the functional layer coating solution, which makes it easier to reduce the burden on the environment. Furthermore, the lower the total concentration of solvents in the optical laminate, the easier it is to suppress deterioration of people's living environments. Furthermore, the lower the total concentration of solvents in the optical laminate, the thinner the penetration layer formed on the functional layer side of the substrate tends to be. Therefore, the total concentration of the solvents in the optical laminate measured by gas chromatography quantitative analysis is set to 15.00 mg / m ２ By using the following solvent, it is possible to reduce the burden on the environment, prevent deterioration of the living environment, and improve the scratch resistance of the optical laminate. The solvent is at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate. The total concentration of the solvent in the optical laminate is 13.50 mg / m ２ Preferably, it is 7.50 mg / m or less. ２If the total concentration of the solvent in the optical laminate is too low, the thickness of the penetration layer may become thin, resulting in insufficient adhesion. Therefore, the total concentration of the solvent in the optical laminate is preferably 0.07 mg / m or less. ２ It is preferable that the concentration is 0.10 mg / m or more. ２ More preferably, it is 0.15 mg / m or more. ２ More preferably, it is equal to or greater than this.

[0052] The optical laminate of the present disclosure contains at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, and the total concentration of toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate is 10.00 mg / m or less by gas chromatography quantitative analysis. ２ It is preferable that:

[0053] Toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone are difficult to volatilize from the functional layer, and therefore remain in the functional layer for a long period of time. Therefore, when at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone is contained, it is likely to cause sick house syndrome. On the other hand, when toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone are contained, it is likely to form a permeation layer in the substrate. Therefore, when the optical laminate contains at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, and the total concentration of these solvents in the optical laminate is 10.00 mg / m ２ By doing as follows, the following effects 1) to 3) can be expected: 1) A permeation layer of an appropriate thickness is formed, which can improve the adhesion between the substrate and the functional layer and suppress the deterioration of the scratch resistance of the optical laminate. 2) The effect of reducing the burden on the environment. 3) The effect of suppressing sick house syndrome.

[0054] The total concentration of at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate is 7.00 mg / m ２More preferably, it is 5.00 mg / m or less. ２ The total concentration of at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate is more preferably 0.10 mg / m or less. ２ It is preferable that the concentration is 0.15 mg / m or more. ２ More preferably, it is equal to or greater than this.

[0055] The optical laminate of the present disclosure contains toluene as a solvent, and the concentration of toluene in the optical laminate is 2.50 mg / m according to gas chromatography quantitative analysis. ２ It is preferable that the optical laminate contains toluene as a solvent, and the concentration of toluene in the optical laminate is 2.50 mg / m or less. ２ By doing the following, the above effects 1) to 3) can be expected.

[0056] The optical laminate of the present disclosure contains at least one solvent selected from methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, and the total concentration of methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate is 3.00 mg / m or less by gas chromatography quantitative analysis. ２ Preferably, it is 2.00 mg / m or less. ２ More preferably, it is 1.00 mg / m or less. ２ It is more preferable that the optical laminate contains at least one solvent selected from methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, and the concentration of the solvent in the optical laminate is 3.00 mg / m or less. ２ By setting the concentration below, the effects 1) to 3) above can be expected. Furthermore, since methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone easily dissolve the substrate, and the components of the substrate easily flow into the functional layer, the total concentration of methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate is set to 3.00 mg / m ２ By setting the following, it is possible to easily improve the scratch resistance of the optical laminate.

[0057] In this specification, the solvent concentration in the optical laminate is measured by the following procedures (1) and (2). The solvent concentration in the optical laminate is measured by sealing a sample taken from the optical laminate in a vial and using the sealed vial. Sealing the sample in the vial is preferably performed within one hour after the optical laminate is completed by forming all functional layers on the substrate. (1) A qualitative analysis of the solvent contained in the optical laminate is performed. (2) A quantitative analysis is performed on the solvent detected in the qualitative analysis (1) above. The quantitative analysis is performed using an absolute calibration curve method. Note that the solvent concentration in the optical laminate does not change significantly after the production of the optical laminate is completed. Therefore, a sample taken from an optical laminate available on the market may be sealed in a vial and the solvent concentration may be measured using the sealed vial. Examples of optical laminates available on the market include optical laminates incorporated into panels or image display devices.

[0058] <Other Properties> The optical laminate preferably has a total light transmittance according to JIS K7361-1:1997 of 70% or more, more preferably 80% or more, and even more preferably 85% or more.

[0059] When an antiglare layer is included as a functional layer, the optical laminate preferably has a haze of 1% or more and 75% or less according to JIS K7136:2000. The lower limit of the haze is more preferably 1% or more, even more preferably 10% or more, and even more preferably 15% or more, and the upper limit is more preferably 70% or less, and even more preferably 65% ​​or less. When an antiglare layer is included as a functional layer, the 60-degree specular gloss measured from the antiglare layer side is preferably 100 or less, more preferably 55 or less, and even more preferably 40 or less, and the lower limit is preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more. In this specification, the 60-degree specular gloss refers to the 60-degree specular gloss measured by measurement method 3 specified in JIS Z8741:1997. In this specification, unless otherwise specified, haze, total luminous transmittance, and 60-degree specular gloss refer to the average of 14 measured values ​​obtained by excluding the maximum and minimum values ​​from 16 measured values. In this specification, the 16 measurement points are determined by excluding a 1 cm margin from the outer edge of the measurement sample, and drawing lines dividing the remaining area into five equal parts vertically and horizontally. The measurement centers are the 16 intersections of these lines. For example, if the measurement sample is rectangular, a 0.5 cm margin is removed from the outer edge of the rectangle, and the measurement is performed with the 16 intersections of the dotted lines dividing the remaining area into five equal parts vertically and horizontally. The average of the 14 measured values ​​obtained by excluding the maximum and minimum values ​​from the 16 measured values ​​is used as the parameter value. If the measurement sample has a shape other than a rectangle, such as a circle, ellipse, triangle, or pentagon, a rectangle inscribed in the shape is drawn, and 16 measurements are performed on the rectangle using the above method.

[0060] In order to reduce the burden on the environment, the proportion of biomass-derived raw materials in the optical laminate is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. If the proportion of biomass-derived raw materials in the optical laminate is too high, the scratch resistance of the optical laminate may decrease. For this reason, the proportion of biomass-derived raw materials in the optical laminate is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less.

[0061] <Size, Shape, etc.> The optical laminate may be in the form of sheets cut to a predetermined size, or in the form of a roll obtained by winding a long sheet into a roll. The size of the sheets is not particularly limited, but the maximum diameter is approximately 2 inches to 500 inches. The "maximum diameter" refers to the maximum length when any two points on the optical laminate are connected. For example, if the optical laminate is rectangular, the diagonal line of the area is the maximum diameter. If the optical laminate is circular, the maximum diameter is the diameter of the circle. The width and length of the roll are not particularly limited, but generally the width is approximately 500 mm to 3000 mm and the length is approximately 500 m to 5000 m. The optical laminate in roll form can be cut into sheets to fit the size of an image display device or the like. When cutting, it is preferable to exclude the ends of the roll, which have unstable physical properties. The shape of the sheets is also not particularly limited, and examples include polygons such as triangles, rectangles, and pentagons, circles, and random, irregular shapes. More specifically, when the optical laminate has a rectangular shape, the aspect ratio is not particularly limited as long as it does not cause any problems as a display screen. For example, width:height ratios of 1:1, 4:3, 16:10, 16:9, 2:1, etc. may be mentioned, but for in-vehicle applications and digital signage, which are rich in design, such aspect ratios are not limited. The total concentration of the solvent in the optical laminate is 15.00 mg / m ２ If it is equal to or less than this, sufficient scratch resistance can be ensured during transportation of the roll-shaped or sheet-shaped optical laminate.

[0062] [Polarizing Plate] The polarizing plate of the present disclosure has a polarizer, a first transparent protective plate arranged on one side of the polarizer, and a second transparent protective plate arranged on the other side of the polarizer, and at least one of the first transparent protective plate and the second transparent protective plate is the optical laminate of the present disclosure described above.

[0063] <Polarizer> Examples of polarizers include sheet-type polarizers such as polyvinyl alcohol films, polyvinyl formal films, polyvinyl acetal films, and saponified ethylene-vinyl acetate copolymer films dyed with iodine or the like and stretched, wire-grid polarizers made of a large number of parallel-arranged metal wires, coated polarizers coated with a lyotropic liquid crystal or a dichroic guest-host material, and multilayer thin-film polarizers. These polarizers may be reflective polarizers that have the function of reflecting polarized light components that are not transmitted.

[0064] <Transparent protective plate> A first transparent protective plate is arranged on one side of the polarizer, and a second transparent protective plate is arranged on the other side. At least one of the first transparent protective plate and the second transparent protective plate is the optical laminate of the present disclosure described above. In the polarizing plate of the present disclosure, one of the first transparent protective plate and the second transparent protective plate may be the optical laminate of the present disclosure described above, or both of the first transparent protective plate and the second transparent protective plate may be the optical laminate of the present disclosure described above.

[0065] Of the first and second transparent protective plates, the transparent protective plate that is not the optical laminate of the present disclosure can be made of a general-purpose plastic film, glass, or the like.

[0066] The polarizer and the transparent protective plate are preferably attached to each other via an adhesive, which may be a general-purpose adhesive, and is preferably a PVA-based adhesive.

[0067] [Faceplate for image display device] The faceplate for an image display device of the present disclosure is a faceplate for an image display device in which a protective film is bonded to a resin plate or a glass plate, and the protective film is the optical laminate of the present disclosure described above.

[0068] As the resin plate or glass plate, a resin plate or glass plate that is generally used as a surface plate of an image display device can be used.

[0069] The thickness of the resin plate or glass plate is preferably 10 μm or more to improve strength. The upper limit of the thickness of the resin plate or glass plate is usually 5000 μm or less. In order to reduce thickness, the upper limit of the thickness of the resin plate or glass plate is preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 100 μm or less. Examples of the thickness range of the resin plate or glass plate include 10 μm or more and 5000 μm or less, 10 μm or more and 1000 μm or less, 10 μm or more and 500 μm or less, and 10 μm or more and 100 μm or less.

[0070] [Panel] The panel of the present disclosure is a panel having a display element and an optical laminate arranged on the light emission surface side of the display element, and the optical laminate includes the optical laminate of the present disclosure described above (see Figure 2).

[0071] Examples of the display element include a liquid crystal display element, an EL display element (organic EL display element, inorganic EL display element), a plasma display element, and further include an LED display element such as a micro LED display element. These display elements may have a touch panel function inside the display element. Examples of the liquid crystal display system of the liquid crystal display element include an IPS system, a VA system, a multi-domain system, an OCB system, an STN system, and a TSTN system.

[0072] The panel of the present disclosure may also be a panel with a touch panel, which has a touch panel between the display element and the optical laminate.

[0073] The size of the panel is not particularly limited, but the maximum diameter is about 2 inches to 500 inches. The maximum diameter means the maximum length when connecting any two points on the surface of the panel.

[0074] [Image Display Device] The image display device of the present disclosure includes the panel of the present disclosure. ２If the thickness is equal to or less than this, sufficient scratch resistance can be ensured during transportation and use of the image display device.

[0075] The image display device of the present disclosure is not particularly limited as long as it includes the panel of the present disclosure. The image display device of the present disclosure preferably includes the panel of the present disclosure, a drive control unit electrically connected to the panel, and a housing that houses these. When the display element is a liquid crystal display element, the image display device of the present disclosure requires a backlight. The backlight is arranged on the side opposite to the light-emitting surface of the liquid crystal display element.

[0076] The size of the image display device is not particularly limited, but the maximum diameter of the effective display area is approximately 2 inches or more and 500 inches or less. The effective display area of ​​an image display device is the area in which an image can be displayed. For example, if the image display device has a housing that surrounds the display element, the area inside the housing is the effective image area. The maximum diameter of the effective image area refers to the maximum length when any two points within the effective image area are connected. For example, if the effective image area is rectangular, the diagonal line of the area is the maximum diameter. Also, if the effective image area is circular, the diameter of the area is the maximum diameter.

[0077] [Method for selecting an optical laminate] The method for selecting an optical laminate according to the present disclosure is to select an optical laminate that satisfies the following selection conditions: (Selection conditions for an optical laminate) An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and a total concentration of the solvents in the optical laminate measured by gas chromatography quantitative analysis is 15.00 mg / m ２ The following is the result.

[0078] The method for selecting an optical laminate of the present disclosure may have additional selection conditions. Examples of the additional selection conditions include preferred embodiments of the optical laminate. Examples of the additional selection conditions include the following A to D. A: The total concentration of the solvent in the optical laminate is 0.07 mg / m ２ 15.00mg / m or more ２ B: The substrate has a permeation layer on the surface having the functional layer, and the thickness of the permeation layer is 5.0 μm or less. C: The total thickness of the functional layers is 20.0 μm or less. D: The proportion of biomass-derived raw materials in the optical laminate is 10 mass% or more.

[0079] According to the method for selecting an optical laminate of the present disclosure, it is possible to efficiently select an optical laminate that reduces the burden on the environment and has excellent scratch resistance.

[0080] The present disclosure includes the following (1) to (13): (1) An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and a total concentration of the solvents in the optical laminate measured by gas chromatography quantitative analysis is 15.00 mg / m ２ (2) The optical laminate contains at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, and the total concentration of toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate is 10.00 mg / m or less as determined by gas chromatography quantitative analysis. ２ (3) The optical laminate according to (1), wherein the total concentration of the solvent in the optical laminate is 0.07 mg / m or less. ２ 15.00mg / m or more ２The optical laminate according to (1) or (2), wherein the substrate has a permeation layer on the surface having the functional layer, and the permeation layer has a thickness of 5.0 μm or less. (4) The optical laminate according to any one of (1) to (3), wherein the substrate has a permeation layer on the surface having the functional layer, and the permeation layer has a thickness of 5.0 μm or less. (5) The optical laminate according to any one of (1) to (4), wherein the functional layers have a total thickness of 20.0 μm or less. (6) The optical laminate according to any one of (1) to (5), wherein the proportion of biomass-derived raw materials in the optical laminate is 10 mass% or more. (7) The optical laminate according to any one of (1) to (6), wherein the functional layer includes one or more layers selected from a hard coat layer, an antiglare layer, an antireflection layer, an antifouling layer, an antistatic layer, and a conductive layer. (8) The optical laminate according to any one of (1) to (7), wherein the substrate is a plastic film. (9) A polarizing plate having a polarizer, a first transparent protective plate arranged on one side of the polarizer, and a second transparent protective plate arranged on the other side of the polarizer, wherein at least one of the first transparent protective plate and the second transparent protective plate is the optical laminate described in any one of (1) to (8). (10) A faceplate for an image display device, comprising a resin plate or a glass plate on which a protective film is laminated, wherein the protective film is the optical laminate described in any one of (1) to (8). (11) A panel having a display element and an optical laminate arranged on the light exit surface side of the display element, wherein the optical laminate comprises the optical laminate described in any one of (1) to (8). (12) An image display device, comprising the panel described in (11). (13) A method for selecting an optical laminate, comprising selecting an optical laminate that satisfies the following selection conditions: (Selection Conditions for Optical Laminate) An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and a total concentration of the solvents in the optical laminate determined by gas chromatography quantitative analysis is 15.00 mg / m ２ The following is the result.

[0081] Next, the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to these examples. Note that "parts" and "%" are based on mass unless otherwise specified.

[0082] 1. Measurement and Evaluation Measurement and evaluation of the optical laminates of Examples, Comparative Examples, and Reference Examples were carried out as follows. The atmosphere during each measurement and evaluation was controlled at a temperature of 23°C ± 1°C and a relative humidity of 40% to 65%, unless otherwise specified. Furthermore, except for the qualitative analysis in 1-1(1) and the quantitative analysis in 1-1(2), the target sample was exposed to the above atmosphere for 30 minutes before starting each measurement and evaluation, and then measurement and evaluation were carried out. The results are shown in Table 1 or 2.

[0083] 1-1. Solvent Concentration Qualitative analysis of the solvent contained in the optical laminates of Examples, Comparative Examples, and Reference Examples was performed. Quantitative analysis was then performed on the detected solvent. Qualitative analysis and quantitative analysis were performed according to the following procedures. Quantitative analysis was completed within one hour after forming the functional layer on the substrate.

[0084] (1) Qualitative Analysis A 5 cm x 5 cm sample for qualitative analysis was cut out from the optical laminate and sealed in a vial attached to the device. The sealing was completed within one hour after the optical laminate was completed. The vial was set in the thermal desorption device described below. Qualitative analysis of the sample was carried out under the following conditions using an apparatus connected to the thermal desorption device described below and the gas chromatograph mass spectrometer described below. Among the peaks obtained, substances with a melting point of 25°C or higher and a boiling point of 200°C or lower were extracted as residual solvents. <Thermal desorption apparatus (pretreatment apparatus)> Apparatus name: JTD505 III (Japan Analytical Industry Co., Ltd.) <Conditions> Sample tube heating temperature: 100°C Cryo-cooling temperature: -60°C Cryo-heating temperature: 315°C Purge time: 20 min Total split ratio (inlet volume: outlet volume) = 1:10 Column flow rate: 2 ml / min <Gas chromatograph mass spectrometer> Apparatus name: Agilent 6890 / 5973 (Agilent Technologies) <Conditions> Column temperature: 50°C x 5 min (hold), 10°C / min (heat increase), 320°C x 3 min (hold) <Column information> Product number: UA-5 (Frontier Labs) Stationary phase: 5% phenyl, 95% dimethylsiloxane Polarity: Slightly polar Inner diameter: 0.25 mm Length: 30 m Film thickness: 0.25 μm

[0085] (2) Quantitative Analysis A 10 cm x 10 cm sample for quantitative analysis was cut out from the optical laminate and sealed in a vial attached to the device. The sealing described above was completed within one hour after the optical laminate was completed. The vial was set in the following device. Regarding the solvents detected in the qualitative analysis in (1) above, quantitative analysis of the sample was carried out using the following device under the following conditions. The concentration of each solvent is shown in Table 2. The following quantitative analysis was performed using an absolute calibration curve method. <Apparatus> Apparatus name: Agilent 6890 (Agilent Technologies) <Conditions> Heating temperature: 120°C Heating time: 30 min Injection port temperature: 250°C Sample injection volume: 1 mL Column temperature: 50°C x 5 min (hold), 10°C / min (heat increase), 200°C (no hold) Split ratio = 20:1 (column flow rate 1.0 ml / min, linear velocity 21 cm / s) Detector: Flame ionization detector (FID) <Column information> Product name: "Equity 1" manufactured by SPELCO Polarity: Nonpolar Stationary phase: 100% dimethylsiloxane Film thickness: 0.25 μm Inner diameter: 0.25 mm Length: 60 m

[0086] The total concentration of residual solvents was calculated from the results of the quantitative analysis in (2) above. Based on the total concentration of residual solvents, the evaluation was performed according to the following criteria: <Environmental contribution (remaining solvent amount)> AA: Total concentration is 1.00 mg / m ２ A: Total concentration is 1.00 mg / m or less ２ Super 10.00mg / m ２ B: Total concentration is 10.00 mg / m or less ２ Super 15.00mg / m ２ C: Total concentration is 15.00 mg / m or less ２ Super

[0087] 1-2. Environmental Contribution (Drying Process) Evaluation was based on the temperature and time required to dry the functional layer, using the following criteria: <Environmental Contribution (Drying Process)> A: 60 seconds or less at 70°C (Note: 60 seconds or less at less than 70°C is also considered "A") B: More than 60 seconds but less than 70 seconds at 70°C C: More than 70 seconds at 70°C

[0088] 1-3. Scratch resistance (1) Load 300g / cm ２The optical laminates obtained in the Examples, Comparative Examples, and Reference Examples were cut into 3 cm x 20 cm samples. The cut locations were selected at random after visually checking for any abnormalities such as dust or scratches. Next, using a steel wool tester (SAM JEE TECK, product name "SJTR-053"), steel wool #0000 (product name: Bonstar, Japan Steel Wool Co., Ltd.) was applied to the functional layer side of the optical laminate sample at a load of 300 g / cm. ２ The sample was pressed against the steel wool and rubbed 10 times back and forth at a speed of 100 mm / sec. The length of the rubbed optical laminate was 17 cm. The contact area between the steel wool and the sample was 4 cm. ２ Then, black tape was attached to the surface of the substrate opposite to the surface having the functional layer. Then, under illumination with a three-wavelength fluorescent lamp, the presence or absence of scratches and discoloration in the functional layer of the sample of the optical laminate was visually confirmed, and the evaluation was based on the following criteria. Discoloration is a phenomenon that occurs when the raised portion of the antiglare layer serving as the functional layer is scraped or deformed. AA: No scratches or discoloration A: No scratches, discoloration B: Discoloration occurs, and the number of scratches is 1 to 10 C: Discoloration occurs, and the number of scratches is 11 to 20 D: Discoloration occurs, and the number of scratches is 21 or more (2) Load 500 g / cm ２ The load was 500 g / cm ２ and evaluated in the same manner as above.

[0089] 1-4. Pencil Hardness Samples were prepared by cutting the optical laminates of the Examples, Comparative Examples, and Reference Examples into 5 cm x 10 cm pieces. The pencil hardness of the functional layer side of the samples was measured in accordance with JIS K5600-5-4:1999, except for the following measurement, heating, and evaluation conditions. A Toyo Seiki Seisakusho pencil hardness tester (product number: NP-type pencil scratch coating hardness tester) was used for the measurement. Both ends of the cut sample were attached to the base of the pencil hardness tester using mending tape (3M, product number "810-3-18") and then measured. <Measurement Conditions> Load: 500 g Speed: 1.4 mm / sec <Sample Heating> After applying a load to the sample under the above measurement conditions, the sample was heated at 100°C for 10 minutes. Immediately after heating, the pencil hardness was evaluated under the following evaluation conditions. <Judgment Criteria> The pencil hardness test was performed five times, and the hardness when no appearance abnormalities such as scratches were observed four or more times was taken as the pencil hardness value of each sample. For example, if the test was performed five times using a 2H pencil and no appearance abnormalities occurred four times, the pencil hardness of that sample was 2H. The appearance abnormalities did not include discoloration, but were checked for scratches. Dents restored by the above-mentioned heating were not counted as appearance abnormalities. A pencil hardness of 2H or more was considered to be a pass level.

[0090] 1-5. Adhesion The adhesion of the optical laminates of Examples, Comparative Examples, and Reference Examples was evaluated using the following method. The evaluation samples were cross-cut into a grid of 10 vertical and 10 horizontal squares, for a total of 100 squares. The cut intervals were 1 mm. When cutting, the cutter blade was inserted from the functional layer side, and the cross-cutting was performed so that the cutter blade reached the top of the substrate. An adhesive tape (manufactured by Nichiban Co., Ltd., product name "Cellotape (registered trademark)") was attached to the surface of the cross-cut sample, and a peel test was performed in accordance with the cross-cut method specified in JIS K 5600-5-6:1999. The number of squares remaining after the peel test out of 100 squares was counted. The closer the number of remaining squares to 100, the better the adhesion.

[0091] 1-6. Interference fringes Two optical laminate sheets were superimposed so that the surface of one optical laminate facing the functional layer and the surface of the other optical laminate facing the substrate. Thereafter, the presence or absence of interference fringes was visually evaluated under illumination with a three-wavelength fluorescent lamp. Those for which no interference fringes were observed were rated "A," and those for which interference fringes were observed were rated "C."

[0092] 1-7. Thickness: The thicknesses of the permeation layer and functional layer were measured using a scanning transmission electron microscope (STEM) using a measurement sample with an exposed cross section of the optical laminate. The measurement sample was prepared according to steps (A1) to (A2) of the present specification. The silicone embedding plate (A1) was manufactured by Dosaka EM Co., Ltd. The epoxy resin used for embedding (A1) was a 10:1.2 mixture of Struers' product name "Epofix" and Struers' product name "Epofix Hardener." The embedding resin (A1) was cured by leaving it at room temperature for 12 hours. The device used to cut the block-shaped embedded sample (A2) was an Ultramicrotome EM UC7 manufactured by Leica Microsystems. When cutting the block-shaped embedded sample, it was first roughly cut (coarse trimming), and finally trimmed precisely under the conditions of "SPEED: 1.00 mm / s" and "FEED: 70 nm." The sample for measurement was stained with osmium tetroxide. The STEM used was the Hitachi High-Technologies Corporation model "S-4800." The imaging conditions were as follows: <Imaging conditions> Mode: TE Acceleration voltage: 30 kV Emission current: 10 uA WD (Working Distance): 8.0 mm Magnification: The following magnifications were selected in high magnification mode. (Functional layer with a thickness of 10 μm to 20 μm: 2000x; functional layer with a thickness of less than 10 μm: 5000x; penetration layer with a thickness of 1 μm to 5 μm: 10,000x; penetration layer with a thickness of less than 1 μm: 500,000x)

[0093] 1-8. Biomass Degree The biomass degree of the optical laminates of the Examples, Comparative Examples, and Reference Examples was measured in accordance with Method B of ASTM D6866-22, with the measured pMC (percent modern carbon) corrected by δ13C.

[0094] 1-9. Total Light Transmittance and Haze (Hz) The optical laminates of the Examples, Comparative Examples, and Reference Examples were cut into 10 cm squares. The cutting locations were selected from random locations after visually confirming that there were no abnormalities such as dust or scratches. Using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory), the total light transmittance of each sample according to JIS K7361-1:1997 and the haze according to JIS K7136:2000 were measured. To allow the light source to stabilize, the device was powered on and then waited for 15 minutes or more, and calibration was performed without setting anything in the entrance opening. After that, the measurement sample was set in the entrance opening and measurement was performed. The light incident surface was on the substrate side.

[0095] 1-10. Anti-glare Properties Samples were prepared by laminating a black plate (Kuraray Co., Ltd., product name "Comoglass DFA2CG 502K (black) series", total light transmittance 0%, thickness 2 mm, refractive index 1.49) to the substrate side of the optical laminates of the Examples, Comparative Examples, and Reference Examples via a 25 μm-thick transparent adhesive layer (Panac Corporation, product name "Panaclean PD-S1", refractive index 1.49) (sample size: 20 cm length x 30 cm width). Under illumination by a three-wavelength fluorescent lamp, 20 subjects evaluated whether or not anti-glare properties were obtained to the extent that the observer's own reflection was not bothersome, according to the following criteria: A: 14 or more people answered that the anti-glare properties were good; B: 7 to 13 people answered that the anti-glare properties were good; C: 6 or less people answered that the anti-glare properties were good.

[0096] 2. Preparation of Optical Laminate [Example 1] The following functional layer coating solution was applied to a substrate (a triacetyl cellulose resin film having a thickness of 80 μm, manufactured by Fujifilm Corporation). The coating solution was then dried at 70° C. and a wind speed of 1.0 m / s for 60 seconds. The coating solution was then dried in a nitrogen atmosphere with an oxygen concentration of 200 ppm or less, with an integrated light intensity of 50 mJ / cm. ２ An antiglare layer having a thickness of 9.0 μm was formed as a functional layer, and an optical laminate of Example 1 was obtained.

[0097] <Functional layer coating liquid> Glycerin triacrylate 100 parts Thickener 5 parts (surface-hydrophobized silica fine particles with an average primary particle diameter of 12 nm) (Nippon Aerosil Co., Ltd., fumed silica) Organic particles 10 parts (spherical polyacrylic-styrene copolymer with an average particle diameter of 3.0 μm, Sekisui Plastics Co., Ltd.) Photopolymerization initiator 5.0 parts (IGM Resins B.V., product name: Omnirad 184) Solvent (MIBK) 0.2 parts

[0098] [Examples 2 to 5], [Comparative Examples 1 and 2], and [Reference Example 1] The type and amount of solvent contained in the functional layer coating liquid were changed to the type and amount of solvent in Table 1. In addition, the drying conditions were changed as follows. Except for these changes, the optical laminates of Examples 2 to 5, Comparative Examples 1 and 2, and Reference Example 1 were obtained in the same manner as in Example 1. <Drying Conditions> Example 2: 50°C, 1.0 m / s wind speed for 60 seconds Example 3: 50°C, 1.0 m / s wind speed for 60 seconds Example 4: 25°C, 60 seconds (no wind speed due to room temperature drying) Example 5: 70°C, 1.0 m / s wind speed for 60 seconds Comparative Example 1: 70°C, 1.0 m / s wind speed for 70 seconds Comparative Example 2: 70°C, 1.0 m / s wind speed for 80 seconds Reference Example 1: 70°C, 1.0 m / s wind speed for 60 seconds

[0099]

[0100]

[0101] The results in Table 2 confirm that the optical laminates of the Examples can reduce environmental impact and improve scratch resistance. In Table 2, "Thickness" is the result of measurement using the embedded sample described above. Furthermore, in Table 2, the items other than "Thickness" are the results of measurement using samples cut out from the optical laminate. It is believed that the haze differs between the optical laminates of Examples 1 to 5, Comparative Examples 1 and 2, and Reference Example 1 due to the following reasons (1) and (2). (1) When an antiglare layer coating liquid containing a resin, particles, and a solvent is applied to a substrate, the surface of the antiglare layer is nearly smooth immediately after application. When the solvent evaporates, the film surface lowers while the position of the particles remains unchanged, increasing surface irregularities and increasing haze. When the coating liquid contains a small amount of solvent, there is little change in the film surface before and after solvent evaporation, making it difficult for irregularities to form and increasing haze. (2) When an antiglare layer coating liquid containing a resin, particles, and a solvent is applied to a substrate, the resin penetrates into the substrate, lowering the film surface, increasing irregularities and increasing haze. Furthermore, the greater the amount of heat required for drying the antiglare layer coating solution, the more easily the resin penetrates into the substrate, and therefore the greater the amount of heat required for drying, the greater the haze tends to become.

[0102] 10: Substrate 20: Functional layer 21: First functional layer 22: Second functional layer 100: Optical laminate 200: Display element 300: Panel

Claims

1. An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and the total concentration of the solvent in the optical laminate as determined by gas chromatography quantitative analysis is 15.00 mg / m ２ The optical laminate is as follows:

2. The optical laminate contains at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone, and the total concentration of toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate is 10.00 mg / m or less as determined by gas chromatography quantitative analysis. ２ The optical laminate according to claim 1, wherein:

3. The total concentration of the solvent in the optical laminate is 0.07 mg / m ２ 15.00mg / m or more ２ The optical laminate according to claim 1, wherein:

4. The optical laminate according to claim 1, wherein the substrate has a permeation layer on the surface having the functional layer, and the thickness of the permeation layer is 5.0 μm or less.

5. The optical laminate according to claim 1, wherein the total thickness of the functional layers is 20.0 μm or less.

6. The optical laminate according to claim 1, wherein the proportion of biomass-derived raw materials in the optical laminate is 10 mass % or more.

7. The optical laminate according to claim 1, comprising, as the functional layer, one or more layers selected from a hard coat layer, an antiglare layer, an antireflection layer, an antifouling layer, an antistatic layer, and a conductive layer.

8. The optical laminate according to claim 1, wherein the substrate is a plastic film.

9. A polarizing plate having a polarizer, a first transparent protective plate arranged on one side of the polarizer, and a second transparent protective plate arranged on the other side of the polarizer, wherein at least one of the first transparent protective plate and the second transparent protective plate is an optical laminate according to any one of claims 1 to 8.

10. A faceplate for an image display device, comprising a resin plate or a glass plate to which a protective film is attached, wherein the protective film is an optical laminate according to any one of claims 1 to 8.

11. A panel having a display element and an optical laminate disposed on the light-emitting surface side of the display element, the optical laminate comprising the optical laminate according to any one of claims 1 to 8.

12. An image display device comprising the panel according to claim 11.

13. A method for selecting an optical laminate, which selects an optical laminate that satisfies the following selection conditions: (Selection conditions for optical laminate) An optical laminate having at least one functional layer on a substrate, the optical laminate containing at least one solvent selected from toluene, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, isopropyl alcohol, methyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate, and a total concentration of the solvents in the optical laminate measured by gas chromatography quantitative analysis is 15.00 mg / m ２ The following is the result.

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