Optical layered body; polarizing plate, surface plate, and image display device using said optical layered body; method for producing optical layered body; and method for selecting optical layered body

Abstract

Provided is an optical layered body capable of suppressing a reduction over time in adhesiveness and scratch resistance. This optical layered body has at least one functional layer on a substrate. The concentration of propyl acetate in the optical layered body is 0.02 mg / m2 to 15.00 mg / m2 as determined by gas chromatography quantitative analysis.

Description

Optical laminate, polarizing plate, surface plate, panel and image display device using said optical laminate, method for manufacturing optical laminate, and method for selecting 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, a method for manufacturing the optical laminate, and a method for selecting the 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 and people in the background, or to suppress surface reflection. As an optical laminate, for example, antiglare films have been proposed in Patent Documents 1 to 3.

[0003] JP 2023-516178 A JP 2021-124616 A JP 2022-183161 A

[0004] The antiglare films of Patent Documents 1 to 3 have an antiglare layer on a substrate and can provide good antiglare properties. However, conventional antiglare films such as those of Patent Documents 1 to 3 frequently suffer from deterioration in adhesion between the substrate and the antiglare layer and deterioration in scratch resistance over time.

[0005] An object of the present disclosure is to provide an optical laminate that can suppress deterioration over time in adhesion and scratch resistance.An object of the present disclosure is to provide a polarizing plate, a faceplate, a panel, and an image display device that can suppress deterioration over time in adhesion and scratch resistance.An object of the present disclosure is to provide a method for efficiently producing an optical laminate that can suppress deterioration over time in adhesion and scratch resistance.An object of the present disclosure is to provide a method for efficiently selecting an optical laminate that can suppress deterioration over time in adhesion and scratch resistance.

[0006] The present disclosure provides the following items <1> to <7>: <1> An optical laminate having at least one functional layer on a substrate, wherein a concentration of propyl acetate in the optical laminate is 0.02 mg / m or less by gas chromatography quantitative analysis. ２15.00mg / m or more ２ <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 according to <1>. <3> A front panel for an image display device, comprising a resin plate or a glass plate on which a protective film is attached, wherein the protective film is the optical laminate according to <1>. <4> A panel having a display element and an optical laminate arranged on a light-emitting surface side of the display element, wherein the optical laminate comprises the optical laminate according to <1>. <5> An image display device, comprising the panel according to <4>. <6> A method for producing an optical laminate, comprising the steps of applying a functional layer coating liquid on a substrate and drying the functional layer coating liquid, wherein the functional layer coating liquid contains propyl acetate as a solvent, and wherein the concentration of propyl acetate in the optical laminate is 0.02 mg / m or less as determined by quantitative gas chromatography analysis. ２ 15.00mg / m or more ２ <7> A method for producing 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, wherein the concentration of propyl acetate in the optical laminate is 0.02 mg / m or less by quantitative gas chromatography analysis. ２ 15.00mg / m or more ２ The optical laminate is as follows:

[0007] The optical laminate, polarizing plate, faceplate, panel, and image display device of the present disclosure can suppress deterioration over time in adhesion and scratch resistance. The manufacturing method of the optical laminate of the present disclosure can efficiently select an optical laminate that can suppress deterioration over time in adhesion and scratch resistance. The selection method of the optical laminate of the present disclosure can efficiently select an optical laminate that can suppress deterioration over time in adhesion and 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, wherein the concentration of propyl acetate in the optical laminate is determined by gas chromatography quantitative analysis to be 0.02 mg / m ２ 15.00mg / m or more 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. An example of the first functional layer 21 is an anti-glare layer. An example of the second functional layer 22 is a low refractive index layer. FIG. 1 is a schematic cross-sectional view. That is, 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 easily form the permeation layer described below, which facilitates the adhesion of the optical laminate. Among plastic films, COP films and polyester films are preferred because they have excellent weather resistance. Plastic films with an easy-adhesion layer formed thereon are also preferred. When propyl acetate penetrates the easy-adhesion layer, the affinity between the easy-adhesion layer and the functional layer increases, which tends to improve the adhesion between the easy-adhesion layer and the functional layer. Therefore, plastic films with an easy-adhesion layer formed thereon are preferred because they facilitate the adhesion of the optical laminate. As plastic films with an easy-adhesion layer formed thereon, polyester films with an easy-adhesion layer formed thereon are preferred, and polyethylene terephthalate films with an easy-adhesion layer formed thereon are more preferred.

[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 １４ The 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] As described below, the optical laminate of the present disclosure contains propyl acetate as a solvent for the functional layer coating liquid. Because propyl acetate has a fast evaporation rate, the desired optical properties can be obtained even at a low drying temperature. In other words, the optical laminate of the present disclosure can easily obtain the desired optical properties even when a plastic film with a low heat resistance temperature is used. Therefore, the optical laminate of the present disclosure can increase the number of substrate options. Examples of plastic films with a low heat resistance temperature include TAC film and acrylic film. In this specification, propyl acetate means at least one of n-propyl acetate and isopropyl acetate.

[0016] 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 reduced. 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 long as the average value measured at any 10 points is the above-mentioned value. An example of a film thickness measuring device is a Digimatic Standard Outside Micrometer (Mitutoyo Corporation, product number "MD C-25SX").

[0017] 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.

[0018] The substrate preferably has a permeation layer on the surface having the functional layer. The presence of the permeation layer can facilitate improving the adhesion between the substrate and the functional layer. The permeation layer can facilitate improving the adhesion between the substrate and the functional layer, and therefore facilitate improving the scratch resistance of the optical laminate. 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 propyl acetate.

[0019] If the thickness of the penetration layer is too thick, the components of the substrate may flow into the functional layer in large quantities, or the components of the functional layer may flow into the substrate in large quantities, resulting in a decrease in the scratch resistance of the optical laminate. Examples of substrate components include resins, plasticizers, and UV absorbers. Plasticizers and UV absorbers tend to reduce the scratch resistance of the optical laminate. Furthermore, if the components of the functional layer flow into the substrate in large quantities, the physical properties of the optical laminate may fluctuate excessively. When the functional layer contains particles and a binder resin, if the binder resin flows into the substrate in large quantities, there is less resin to bind the particles, making them more likely to be scraped off, which tends to reduce the scratch resistance of the optical laminate. Furthermore, if the binder resin flows into the substrate in large quantities, the particles are excessively exposed on the surface of the functional layer, which tends to whiten the optical laminate and significantly change its appearance. If the thickness of the penetration layer is too thin, it may be difficult to achieve good adhesion between the substrate and the functional layer. Therefore, the thickness of the penetration layer is preferably 0.20 μm or more and 1.50 μm or less, more preferably 0.30 μm or more and 1.00 μm or less, and even more preferably 0.53 μm or more and 0.70 μm or less.

[0020] 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 0.20 μm to 1.50 μm, 0.20 μm to 1.00 μm, 0.20 μm to 0.70 μm, 0.30 μm to 1.50 μm, 0.30 μm to 1.00 μm, 0.30 μm to 0.70 μm, 0.53 μm to 1.50 μm, 0.53 μm to 1.00 μm, and 0.53 μm to 0.70 μm.

[0021] The ratio of the thickness of the penetration layer to the thickness of the substrate is preferably 0.001 or more and 0.500 or less, more preferably 0.003 or more and 0.350 or less, and even more preferably 0.005 or more and 0.200 or less. By setting the ratio to 0.001 or more, it is possible to easily improve the adhesion between the substrate and the functional layer. By setting the ratio to 0.500 or less, it is possible to easily suppress a decrease in the strength of the substrate and a decrease in the scratch resistance of the optical laminate.

[0022] 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.

[0023] (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.

[0024] 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.

[0025] 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.

[0026] <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.

[0027] 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

[0028] 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 propyl acetate 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 2.0 μm or more, more preferably 4.0 μm or more, and even more preferably 6.0 μm or more.

[0029] 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.

[0030] The functional layer includes, for example, a binder component and an additive.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The functional layer such as the antiglare layer may contain particles, such as one or more types of particles selected from organic particles and inorganic particles.

[0043] 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.

[0044] 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 means the value determined as the volume average value d50 by laser diffraction method.

[0045] The particle content, relative to 100 parts by mass of the binder component, is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 2.0 parts by mass or more, and the upper limit is preferably 30.0 parts by mass or less, more preferably 25.0 parts by mass or less, and even more preferably 20.0 parts by mass or less.

[0046] A functional layer such as a low refractive index layer may contain low refractive index particles. Examples of the 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 preferable 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.

[0047] The average primary particle diameters of low refractive index particles and high refractive index particles, which will be 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 acceleration 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 of each particle is determined as the maximum distance between two parallel lines when the cross section of each particle is sandwiched between the two lines. (B3) The same procedure is performed five times using a different image of the same sample, and the value obtained from the number average of the particle diameters of a total of 50 particles is defined as the average primary particle diameter of the particles.

[0048] 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.

[0049] - 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 or the like. After applying the functional layer coating liquid to the substrate or the like, a drying step may be carried out as necessary. Examples of coating methods include gravure coating, bar coating, die coating, and roll coating.

[0050] 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.

[0051] The optical laminate of the present disclosure uses at least propyl acetate as a solvent for the functional layer coating solution. In this specification, propyl acetate refers to at least one of n-propyl acetate and isopropyl acetate. Propyl acetate has a fast evaporation rate, allowing the desired optical properties to be obtained even at low drying temperatures. Therefore, using propyl acetate as a solvent is preferable in that it increases the range of substrate options. Propyl acetate also reduces the energy required for drying, thereby facilitating a reduction in environmental impact. Propyl acetate also shortens drying time, thereby increasing production speed. Propyl acetate easily improves compatibility with the substrate, making it easy to form a permeation layer in the substrate. Therefore, using propyl acetate as a solvent is preferable in that it easily improves adhesion between the substrate and the functional layer. Propyl acetate is particularly compatible with triacetyl cellulose films and acrylic films, which have low heat resistance. Furthermore, propyl acetate makes it easy to control the thickness of the permeation layer within the above-mentioned range, thereby making it easy to improve adhesion while suppressing a decrease in the scratch resistance of the optical laminate. Solvents other than propyl acetate, such as carbonate esters such as dimethyl carbonate, are also solvents that have excellent compatibility with the substrate. However, solvents other than propyl acetate that have excellent compatibility with the substrate make it difficult to control the thickness of the penetration layer within the above-mentioned range. For example, dimethyl carbonate, which is too compatible with the substrate, increases the thickness of the penetration layer too much, thereby reducing the scratch resistance of the optical laminate and worsening the appearance of the optical laminate. Toluene, which is widely used as a solvent, does not exhibit the above-mentioned effects of propyl acetate due to its low compatibility with the substrate. Furthermore, alkyl acetates other than propyl acetate, such as methyl acetate, ethyl acetate, and butyl acetate, are structurally similar to propyl acetate but do not exhibit the above-mentioned effects of propyl acetate. The above-mentioned effects of propyl acetate are thought to be due to the inherent properties of propyl acetate, such as its solubility parameter and boiling point. The above-mentioned effects of propyl acetate can be obtained with both n-propyl acetate and isopropyl acetate.The proportion of propyl acetate relative to the total amount of the solvent in the functional layer coating liquid is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0052] As described above, alkyl acetates other than propyl acetate, such as methyl acetate, ethyl acetate, and butyl acetate, do not exhibit the effects of propyl acetate. Furthermore, alkyl acetates other than propyl acetate tend to inhibit the effects of propyl acetate. Therefore, the proportion of alkyl acetates other than propyl acetate to the total amount of solvent in the functional layer coating solution is preferably 9% by mass or less, more preferably 6% by mass or less.

[0053] Alkyl lactates such as methyl lactate and ethyl lactate are highly miscible with water. Therefore, when a functional layer coating solution contains alkyl lactate, moisture in the air is easily absorbed into the functional layer during the production process. Absorption of moisture in the air into the functional layer can lead to problems such as reduced particle dispersibility and reduced physical properties of the functional layer. Furthermore, alkyl lactates have a slow evaporation rate, making it difficult to achieve the desired optical properties when the drying temperature is lowered. For these reasons, alkyl lactates tend to inhibit the effects of propyl acetate. Therefore, the ratio of alkyl lactate to the total amount of solvent in the functional layer coating solution is preferably 9% by mass or less, more preferably 6% by mass or less.

[0054] The mass ratio of the solvent to the total amount of the functional layer coating liquid is preferably 20% by mass or more and 90% by mass or less, more preferably 40% by mass or more and 80% by mass or less, and even more preferably 50% by mass or more and 70% by mass or less. By making the solvent ratio 20% by mass or more, it is possible to easily improve the adhesion between the substrate and the functional layer. Furthermore, by making the solvent ratio 20% by 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 90% by mass or less, the concentration of propyl acetate in the optical laminate can be reduced to 15.00 mg / m ２Furthermore, by setting the solvent ratio to 90% by 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 90% by 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.

[0055] Toluene is difficult to volatilize, so it remains in the functional layer for a long time. Therefore, when toluene is contained, it is likely to cause sick house syndrome and deteriorate the living environment of people. Therefore, the proportion of toluene to the total amount of solvent in the functional layer coating solution is preferably 10% by mass or less, more preferably 5.5% by mass or less, and even more preferably 5% by mass or less. In addition to toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone also remain in the functional layer for a long time, which is likely to cause sick house syndrome. Therefore, the proportion 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 solution is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0056] 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 concentration of solvents such as propyl acetate 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 concentration of solvents such as propyl acetate 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 concentration of solvents such as propyl acetate 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 concentration of solvents such as propyl acetate in the optical laminate. For these reasons, the drying temperature is preferably 30°C or higher and 120°C or lower, more preferably 50°C or higher and 80°C or lower. The drying air speed is preferably 0.2 m / s or higher and 50 m / s or lower, more preferably 2 m / s or higher and 40 m / s or lower. The drying time is preferably 5 seconds or higher and 180 seconds or lower, more preferably 15 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.

[0057] The optical laminate of the present disclosure has a propyl acetate concentration of 0.02 mg / m ２ 15.00mg / m or more ２ It is required that:

[0058] The higher the concentration of propyl acetate in the optical laminate, the thicker the penetration layer formed on the functional layer side of the substrate tends to be. ２By setting the concentration to the above, it is possible to easily improve the adhesion between the substrate and the functional layer. Propyl acetate has good compatibility with the substrate, so it can not only improve the initial adhesion but also improve the adhesion over time. Furthermore, since it can improve the adhesion over time, it is possible to suppress the deterioration of scratch resistance over time. The lower the concentration of propyl acetate in the optical laminate, the thinner the thickness of the penetration layer formed on the functional layer side of the substrate, which tends to reduce the amount of substrate components that flow into the functional layer. Furthermore, the lower the concentration of propyl acetate in the optical laminate, the easier it is to harden the resin of the functional layer. For this reason, it is preferable to set the concentration of propyl acetate in the optical laminate to 15.00 mg / m ２ By setting the concentration of propyl acetate in the optical laminate to 15.00 mg / m or less, it is possible to easily prevent the scratch resistance of the optical laminate from decreasing. ２ The concentration of propyl acetate in the optical laminate is 0.05 mg / m or less, which can easily reduce the burden on the environment. ２ 10.00mg / m or more ２ Preferably, it is 0.10 mg / m or less. ２ 5.00mg / m or more ２ More preferably, it is:

[0059] As described above, alkyl acetates other than propyl acetate, such as methyl acetate, ethyl acetate, and butyl acetate, do not exhibit the effects of propyl acetate. Furthermore, alkyl acetates other than propyl acetate tend to inhibit the effects of propyl acetate. For this reason, the optical laminate of the present disclosure has a concentration of alkyl acetates other than propyl acetate of 0.35 mg / m2 or less by gas chromatography quantitative analysis. ２ The concentration is preferably 0.30 mg / m or less. ２ More preferably, it is 0.20 mg / m or less. ２ More preferably, it is 0.15 mg / m or less. ２ Even more preferably:

[0060] Alkyl lactates such as methyl lactate and ethyl lactate are highly miscible with water. Therefore, when a functional layer coating solution contains alkyl lactate, moisture in the air is easily absorbed into the functional layer during the production process. When moisture in the air is absorbed into the functional layer, problems such as reduced particle dispersibility and reduced physical properties of the functional layer may occur. Furthermore, since alkyl lactate has a slow evaporation rate, it is difficult to obtain the desired optical properties when the drying temperature is lowered. For these reasons, alkyl lactate tends to inhibit the effects of propyl acetate described above. Therefore, the optical laminate of the present disclosure has a concentration of alkyl lactate in the optical laminate of 0.45 mg / m by gas chromatography quantitative analysis. ２ Preferably, the concentration is 0.40 mg / m or less. ２ More preferably, it is 0.30 mg / m or less. ２ More preferably, it is 0.15 mg / m or less. ２ Even more preferably:

[0061] The optical laminate of the present disclosure has a toluene concentration of 0.20 mg / m according to gas chromatography quantitative analysis. ２ The toluene concentration is preferably 0.17 mg / m or less. ２ More preferably, it is 0.15 mg / m or less. ２ Toluene is difficult to volatilize, so it remains in the functional layer for a long period of time. ２ By setting the concentration of toluene to the following value, it is possible to easily suppress sick house syndrome. Toluene easily improves the dispersibility of particles, so that foreign matter or whitening due to particle aggregation is unlikely to occur. Therefore, when the functional layer contains particles, the concentration of toluene in the optical laminate is 0.01 mg / m or less by gas chromatography quantitative analysis. ２ 0.20mg / m or more ２ Preferably, it is 0.05 mg / m or less. ２ 0.20mg / m or more ２ The following is more preferred:

[0062] The optical laminate of the present disclosure has a total concentration of toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone in the optical laminate of 1.00 mg / m as determined by gas chromatography quantitative analysis. ２ The total concentration is preferably 0.80 mg / m or less. ２ More preferably, it is 0.50 mg / m or less. ２ Toluene, methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone are difficult to volatilize, and therefore remain in the functional layer for a long period of time. ２ By doing the following, it is possible to easily suppress sick house syndrome.

[0063] In this specification, the concentration of a solvent such as propyl acetate contained in an optical laminate is measured by the following procedures (1) and (2). Furthermore, the concentration of the solvent 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 concentration of the solvent 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.

[0064] <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.

[0065] When the optical laminate includes an antiglare layer as a functional layer, the haze of the optical laminate according to JIS K7136: 2000 is preferably 1% or more and 75% or less. 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.

[0066] When an antiglare layer is included as a functional layer, the upper limit of 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 means the 60-degree specular gloss measured by measurement method 3 specified in JIS Z8741:1997.

[0067] 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. 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 remaining area divided 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.

[0068] <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. 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.

[0069] [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.

[0070] <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 that have been dyed with iodine or the like and stretched; wire-grid polarizers made of a large number of metal wires arranged in parallel; coating-type polarizers coated with a lyotropic liquid crystal or a dichroic guest-host material; and multilayer thin-film polarizers. These polarizers may also be reflective polarizers that have the function of reflecting polarized light components that are not transmitted.

[0071] <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.

[0072] 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.

[0073] 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.

[0074] [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.

[0075] 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.

[0076] 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.

[0077] [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).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] [Image Display Device] The image display device of the present disclosure includes the panel of the present disclosure. ２ If the thickness is equal to or less than this, sufficient scratch resistance can be ensured during transportation and use of the image display device.

[0082] 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.

[0083] 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.

[0084] [Method for manufacturing an optical laminate] The method for manufacturing an optical laminate according to the present disclosure is as follows: A method for manufacturing an optical laminate, comprising the steps of applying a functional layer coating liquid onto a substrate and drying the functional layer coating liquid, wherein the functional layer coating liquid contains propyl acetate as a solvent, and the concentration of propyl acetate in the optical laminate is determined by gas chromatography quantitative analysis to be 0.02 mg / m ２ 15.00mg / m or more ２ A method for producing an optical laminate, which is produced as follows.

[0085] In the method for producing an optical laminate according to the present disclosure, the embodiments of the substrate, the composition of the functional layer coating liquid, the coating method of the functional layer coating liquid, the drying conditions of the functional layer coating liquid, etc. can be the same as those exemplified in the optical laminate according to the present disclosure. For example, in the method for producing an optical laminate according to the present disclosure, the concentration of alkyl acetates other than propyl acetate in the optical laminate can be 0.35 mg / m ２ In addition, in the method for producing an optical laminate according to the present disclosure, it is preferable that the concentration of alkyl lactate in the optical laminate is 0.45 mg / m or less.２ In addition, in the method for producing an optical laminate according to the present disclosure, it is preferable that the concentration of toluene in the optical laminate is 0.20 mg / m or less. ２ It is preferable to manufacture it as follows.

[0086] According to the method for producing an optical laminate of the present disclosure, an optical laminate that can suppress deterioration over time in adhesion and scratch resistance can be efficiently produced.

[0087] [Method for selecting an optical laminate] The method for selecting an optical laminate of the present disclosure is to select an optical laminate that satisfies the following selection conditions: (Conditions for selecting an optical laminate) An optical laminate having at least one functional layer on a substrate, wherein, with respect to the concentration of propyl acetate in the optical laminate as determined by gas chromatography quantitative analysis, the concentration of propyl acetate is 0.02 mg / m ２ 15.00mg / m or more ２ The optical laminate is as follows:

[0088] The method for selecting an optical laminate of the present disclosure may have one or more 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 F. A: The concentration of toluene in the optical laminate is 0.20 mg / m ２ B: The substrate has a permeation layer on the surface having the functional layer, and the thickness of the permeation layer is 0.20 μm or more and 1.50 μm or less. C: The functional layer contains particles. D: The total light transmittance of the optical laminate is 80% or more. E: The concentration of alkyl acetates other than propyl acetate in the optical laminate is 0.35 mg / m ２ F: The concentration of alkyl lactate in the optical laminate is 0.45 mg / m or less. ２ below.

[0089] According to the method for selecting an optical laminate of the present disclosure, it is possible to efficiently select an optical laminate that can suppress deterioration over time in adhesion and scratch resistance.

[0090] The present disclosure includes the following items <1> to <16>. <1> An optical laminate having at least one functional layer on a substrate, wherein a concentration of propyl acetate in the optical laminate is 0.02 mg / m or less by gas chromatography quantitative analysis. ２ 15.00mg / m or more ２ <2> The optical laminate according to <1>, wherein the propyl acetate is at least one of n-propyl acetate and isopropyl acetate. <3> A toluene concentration in the optical laminate measured by gas chromatography quantitative analysis is 0.20 mg / m or less. ２ <4> The optical laminate according to any one of <1> to <3>, wherein the substrate has a penetration layer on the side having the functional layer, and the penetration layer has a thickness of 0.20 μm or more and 1.50 μm or less. <5> The optical laminate according to any one of <1> to <4>, wherein the functional layer contains particles. <6> The optical laminate according to <5>, wherein the particles contain one or more types of particles selected from organic particles and inorganic particles. <7> The optical laminate according to <1>, wherein the concentration of toluene in the optical laminate is 0.05 mg / m or less by quantitative gas chromatography analysis. ２ 0.20mg / m or more ２ <8> The optical laminate according to <5>, wherein the concentration of alkyl acetates other than propyl acetate in the optical laminate is 0.35 mg / m or less, as determined by gas chromatography quantitative analysis. ２ <9> The optical laminate according to any one of <1> to <7>, wherein the concentration of alkyl lactate in the optical laminate is 0.45 mg / m or less by gas chromatography quantitative analysis. ２The optical laminate according to any one of <1> to <8>, which is as follows: <10> The optical laminate according to any one of <1> to <9>, which includes an antiglare layer as the functional layer. <11> 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 according to any one of <1> to <10>. <12> A front panel for an image display device, which has a protective film attached to a resin plate or a glass plate, wherein the protective film is the optical laminate according to any one of <1> to <10>. <13> A panel having a display element and an optical laminate arranged on the light-emitting surface side of the display element, wherein the optical laminate comprises the optical laminate according to any one of <1> to <10>. <14> An image display device, which includes the panel according to <13>. <15> A method for producing an optical laminate, comprising: a step of applying a functional layer coating liquid onto a substrate; and a step of drying the functional layer coating liquid, wherein the functional layer coating liquid contains propyl acetate as a solvent, and a concentration of propyl acetate in the optical laminate determined by gas chromatography quantitative analysis is 0.02 mg / m ２ 15.00mg / m or more ２ <16> A method for producing 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, wherein the concentration of propyl acetate in the optical laminate is 0.02 mg / m or less by quantitative gas chromatography analysis. ２ 15.00mg / m or more ２ The optical laminate is as follows:

[0091] 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.

[0092] 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.

[0093] 1-1. Solvent Concentration Qualitative analysis of solvents such as propyl acetate contained in the optical laminates of the Examples, Comparative Examples, and Reference Examples was performed. Quantitative analysis was then performed on the detected solvents. Qualitative analysis and quantitative analysis were performed according to the following procedures. Quantitative analysis was completed within one hour after the functional layer was formed on the substrate.

[0094] (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

[0095] (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 of the completion of the optical laminate. 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 the absolute calibration curve method. <Apparatus> Apparatus name: HP-5973N (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: "InertCap5MS / Sil" manufactured by GL Sciences Polarity: Slightly polar Stationary phase: 100% dimethylsiloxane Film thickness: 0.25 μm Inner diameter: 0.25 mm Length: 30 m

[0096] 1-2. Adhesion (1) Initial 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.

[0097] (2) Adhesion after durability test After the optical laminates of Examples, Comparative Examples, and Reference Examples were subjected to the following durability test, adhesion was evaluated in the same manner as in (1) above. <Durability test> An ultraviolet carbon arc lamp type light resistance and weather resistance tester (trade name "FAL-AU.B" manufactured by Suga Test Instruments Co., Ltd.) conforming to JIS B7751:2007 was used. ２ The optical laminates of Examples, Comparative Examples, and Reference Examples were placed in a black panel (black panel temperature: 63° C.) with the functional layer side facing the light source, and a test was carried out for 200 hours.

[0098] 1-3. Scratch resistance after durability test The above durability test was carried out on the optical laminates of Examples, Comparative Examples, and Reference Examples. Samples were prepared by cutting the optical laminates after the durability test into 3 cm x 20 cm pieces. The cut locations were selected randomly 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 1000 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 evaluated according to the following criteria. Discoloration is a phenomenon that occurs when the raised portion of the antiglare 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

[0099] 1-4. Thickness The thickness of the permeation layer was 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 the same company's 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 Leica Microsystems' product name "Ultramicrotome EM UC7." 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 Hitachi High-Technologies Corporation's model number "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: 100,000x in high magnification mode.

[0100] 1-5. 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. The power switch of the device was turned on in advance to allow the light source to stabilize, and then 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.

[0101] 1-6. 60 Degree Specular Gloss A 10 cm x 5 cm sample was cut out from the optical laminates of the Examples, Comparative Examples, and Reference Examples. The samples were visually inspected for the absence of any abnormalities such as dust or scratches. A non-glossy black resin plate was attached to the substrate side of the sample using the air suction method, and then the 60 degree specular gloss was measured from the functional layer side of the sample. A gloss meter "GM-26PRO" manufactured by Murakami Color Research Laboratory was used to measure the specular gloss. The black resin plate was an accessory to the gloss meter.

[0102] 1-7. Appearance Quality 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). The samples were placed on a horizontal stand and evaluated by 20 subjects in a bright room environment (illuminance on the optical laminate: 500-1000 lux. Lighting: Hf32 type straight tube three-wavelength daylight white fluorescent lamp. The lighting was positioned 2 m vertically above the horizontal stand). The evaluation criteria were "whether antiglare properties were obtained to the extent that the viewer's own reflection was not noticeable" and "whether whitening was not noticeable," and the results were ranked according to the following criteria. A: 14 or more people answered that the anti-glare properties are good and that they are not bothered by whitening. B: 7 to 13 people answered that the anti-glare properties are good and that they are not bothered by whitening. C: 6 or less people answered that the anti-glare properties are good and that they are not bothered by whitening.

[0103] 2. Preparation of Optical Laminate [Example 1] The following functional layer coating solution was applied to a substrate (a 40 μm-thick triacetyl cellulose resin film, Fujifilm Corporation). The coating solution was then dried at 80° C. and a wind speed of 10 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 150 mJ / cm. ２ An antiglare layer having a thickness of 4.8 μm was formed as a functional layer, and an optical laminate of Example 1 was obtained.

[0104] <Functional layer coating liquid> Binder component 100 parts (pentaerythritol triacrylate) (Nippon Kayaku Co., Ltd., trade name: KAYARAD-PET-30) Organic particles 1.0 part (Sekisui Plastics Co., Ltd., spherical polyacrylic-styrene copolymer, average particle size 3.0 μm, refractive index 1.550) Inorganic particles Silica particles 14 parts (average particle size: 4.1 μm) (Fuji Silysia Chemical Ltd., gel-process amorphous silica) Photopolymerization initiator 5 parts (IGM Resins B.V., trade name: Omnirad 184) Silicone-based leveling agent 0.2 parts (Momentive Performance Materials, trade name: TSF4460) Solvent (n-propyl acetate) 175 parts Solvent (MIBK) 10 parts Solvent (ethyl acetate) 5.2 parts

[0105] [Examples 2 to 10], [Comparative Examples 1 to 4], [Reference Examples 1 and 2] 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 to the conditions in Table 1. Except for these changes, the optical laminates of Examples 2 to 10, Comparative Examples 1 to 4, and Reference Examples 1 and 2 were obtained in the same manner as in Example 1.

[0106]

[0107]

[0108] The results in Table 2 confirm that the optical laminates of the Examples have good adhesion and scratch resistance after durability tests and are able to suppress deterioration of adhesion and scratch resistance over time. Table 1 shows that toluene was not added as a solvent to the functional layer coating liquids of Examples 1 to 10, Comparative Examples 2 to 4, and Reference Examples 1 and 2, but toluene was detected in the optical laminates of Examples 1 to 10 and Comparative Examples 2 to 6 in Table 2. This is because toluene contained as a residual solvent in the binder component and photopolymerization initiator was detected. In Table 2, the "thickness of the penetration layer" is the result of measurement using the embedded sample described above. In Table 2, the items other than the "thickness of the penetration layer" are the results of measurement using samples cut out from the optical laminate.

[0109] 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, wherein the concentration of propyl acetate in the optical laminate is 0.02 mg / m or less by gas chromatography quantitative analysis. ２ 15.00mg / m or more ２ The optical laminate is as follows:

2. The optical laminate according to claim 1, wherein the propyl acetate comprises at least one of n-propyl acetate and isopropyl acetate.

3. The concentration of toluene in the optical laminate was 0.20 mg / m by gas chromatography quantitative analysis. 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 0.20 μm or more and 1.50 μm or less.

5. The optical laminate according to claim 1, wherein the functional layer contains particles.

6. The optical laminate according to claim 5, wherein the particles include one or more types of particles selected from organic particles and inorganic particles.

7. The concentration of toluene in the optical laminate is 0.05 mg / m by gas chromatography quantitative analysis. ２ 0.20mg / m or more ２ The optical laminate according to claim 5, wherein:

8. The concentration of alkyl acetate other than propyl acetate in the optical laminate is 0.35 mg / m by gas chromatography quantitative analysis. ２ The optical laminate according to claim 1, wherein:

9. The concentration of alkyl lactate in the optical laminate is 0.45 mg / m by gas chromatography quantitative analysis. ２ The optical laminate according to claim 1, wherein:

10. The optical laminate according to claim 1, which comprises an antiglare layer as the functional layer.

11. 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 10.

12. 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 10.

13. A panel having a display element and an optical laminate placed 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 10.

14. An image display device comprising the panel according to claim 13.

15. A method for producing an optical laminate, comprising the steps of applying a functional layer coating liquid onto a substrate and drying the functional layer coating liquid, wherein the functional layer coating liquid contains propyl acetate as a solvent, and the concentration of propyl acetate in the optical laminate is 0.02 mg / m or less by gas chromatography quantitative analysis. ２ 15.00mg / m or more ２ A method for producing an optical laminate, which is produced as follows.

16. A method for selecting an optical laminate, comprising selecting 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, wherein the concentration of propyl acetate in the optical laminate is 0.02 mg / m or less as determined by quantitative gas chromatography analysis. ２ 15.00mg / m or more ２ The optical laminate is as follows:

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