Polarizing plate and organic electroluminescent display device

Abstract

This invention provides a polarizing plate with extremely excellent durability. The polarizing plate according to an embodiment of this invention comprises: a polarizing element having a first main surface and a second main surface facing each other; a laminated film disposed on the first main surface side of the polarizing element, and sequentially including a substrate and a hard coating layer from the polarizing element side; and a retardation layer disposed on the second main surface side of the polarizing element; the moisture permeability of the laminated film is 600 g / m²·24 h or less, the moisture permeability change rate of the laminated film obtained by placing the laminated film in an environment of 65°C and 95%RH for 48 hours is 1.5 or less, and the moisture permeability of the retardation layer is 200 g / m²·24 h or less.

Description

Polarizing plate and organic electroluminescent display device This invention relates to a polarizing plate and an organic electroluminescent (EL) display device. In recent years, with the widespread adoption of thin-film displays, displays equipped with organic EL panels (organic EL display devices) have been proposed. Because organic EL panels have a highly reflective metal layer, they are prone to problems such as external light reflection or background reflection. Therefore, it is known to prevent these problems by providing a polarizing plate with a retardation layer, which combines a polarizing plate and a retardation plate, on the viewing side of the organic EL panel body (e.g., Patent Document 1 and Patent Document 2). Previous Art Documents Patent Documents Patent Document 1: Japanese Patent Application Publication No. 2002-372622; Patent Document 2: Japanese Patent Publication No. 3325560 [The problem the invention aims to solve] With the increasing popularity of thin-film displays, organic EL display devices sometimes require extremely high moisture resistance, and polarizers also sometimes require extremely high moisture resistance. Moreover, polarizers installed in organic EL display devices are prone to discoloration, and there is a tendency for discoloration to be accelerated in high humidity environments. This invention was made to solve the above-mentioned problems, and its main objective is to provide a polarizing plate with extremely excellent durability. [Technical means to solve the problem] The polarizing plate according to an embodiment of the present invention comprises: a polarizing element having a first main surface and a second main surface facing each other; a laminated film disposed on the first main surface side of the polarizing element, and sequentially comprising a substrate and a hard coating layer from the polarizing element side; and a retardation layer disposed on the second main surface side of the polarizing element; the moisture permeability of the laminated film is 600 g / m². 2 • For laminated films placed at 65°C and 95%RH for 48 hours, the change rate of moisture permeability is less than 1.5, and the moisture permeability of the phase retardation layer is 200 g / m². 2• Less than 24 hours. In one embodiment, the change rate is 1.1 or more. In one embodiment, the thickness of the hard coating is 1 μm or more. In one embodiment, the thickness of the hard coating is 7 μm or less. In one embodiment, the laminated film includes an intermediate layer between the substrate and the hard coating, the intermediate layer including components derived from the substrate and components derived from the hard coating. In one embodiment, the retardation layer is disposed adjacent to the polarizing element. In one embodiment, the Re(450) / Re(550) of the retardation layer is 0.8 or more and less than 1. In one embodiment, the transmittance of the polarizing element is 43.0% or more. In one embodiment, the thickness of the polarizing element is 10 μm or less. According to another aspect of the present invention, an organic electroluminescent display device is provided. The organic electroluminescent display device includes the above-mentioned polarizing plate. [Effects of the Invention] According to embodiments of the present invention, a polarizing plate with extremely excellent durability can be provided. The following describes embodiments of the present invention, but the present invention is not limited to these embodiments. Furthermore, in the drawings, to make the explanation clearer, the width, thickness, shape, etc. of each part are sometimes shown schematically compared to the embodiments, but this is only an example and does not limit the interpretation of the present invention. (Definitions and Symbols) The terms and symbols used in this specification are defined as follows: (1) Refractive Index (nx, ny, nz) "nx" is the refractive index in the direction of maximum refractive index in the plane (i.e., the slow axis direction), "ny" is the refractive index in the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) In-plane Phase Difference (Re) "Re(λ)" is the in-plane phase difference measured with light at a wavelength of λnm at 23°C. For example, "Re(550)" is the in-plane phase difference measured with light at a wavelength of 550 nm at 23°C. When the thickness of the layer (film) is set as d (nm), Re(λ) is obtained by the formula: Re(λ)=(nx-ny)×d. (3) Phase Difference in the Thickness Direction (Rth) "Rth(λ)" is the phase difference in the thickness direction measured with light at a wavelength of λnm at 23°C. For example, "Rth(550)" is the phase difference in the thickness direction measured with light at a wavelength of 550 nm at 23°C. When the thickness of the layer (film) is set as d (nm), Rth(λ) is obtained by the formula: Rth(λ)=(nx-nz)×d. (4) Nz coefficient The Nz coefficient is obtained by Nz=Rth / Re. (5) Angle When an angle is mentioned in this specification, the angle includes both clockwise and counterclockwise directions relative to the reference direction. Therefore, for example, "45°" means ±45°. A. Polarizing Plate Figure 1 is a schematic cross-sectional view showing a schematic configuration of a polarizing plate according to one embodiment of the present invention, and Figure 2 is a cross-sectional view showing an example of a schematic configuration of the laminated film of the polarizing plate shown in Figure 1. The polarizing plate (polarizing plate with a retardation layer) 100 includes: a polarizing element 10 having a first main surface 10a and a second main surface 10b facing each other; a laminated film 20 disposed on the first main surface 10a side of the polarizing element 10; and a retardation layer 30 and an adhesive layer 40 disposed on the second main surface 10b side of the polarizing element 10. The laminated film 20 sequentially includes a substrate 21 and a hard coating 22 from the polarizing element 10 side, and the substrate 21 functions as a protective layer for the polarizing element 10. The polarizing plate 100 is typically configured in an organic EL display device such that the laminated film 20 is on the viewing side relative to the polarizing element 10. In the example shown, the retardation layer 30 is a single layer, but it may also have a multilayer structure with two or more layers, unlike the example shown. Specifically, the retardation layer 30 may comprise two or more layers with different optical properties (e.g., refractive index characteristics, in-plane phase difference, Nz coefficient, photoelastic modulus). Furthermore, in the example shown, no protective layer is disposed between the polarizing element 10 and the retardation layer 30; the retardation layer 30 is disposed adjacent to the polarizing element 10 and functions as a protective layer for the polarizing element 10. However, the polarizing plate 100 may also have a protective layer disposed between the polarizing element 10 and the retardation layer 30. Moreover, "adjacent" includes not only direct adjacency but also adjacency separated by the following bonding layer. The components constituting the polarizing plate can be laminated with any suitable adhesive layer (not shown). Specific examples of adhesive layers include adhesive layers and bonding agents. For example, the laminated film 20 is bonded to the polarizing element 10 with an adhesive layer (preferably using an active energy line curing adhesive). For example, the retardation layer 30 is bonded to the polarizing element 10 or a protective layer (not shown) with an adhesive layer (preferably using an active energy line curing adhesive) or with an adhesive layer (e.g., an acrylic adhesive). When the retardation layer 30 has a laminated structure with two or more layers, each retardation layer is bonded with an adhesive layer (preferably using an active energy line curing adhesive) in between. The thickness of the adhesive layer is preferably 0.4 μm or more, more preferably 0.4 μm to 3.0 μm, and even more preferably 0.6 μm to 1.5 μm. The thickness of the adhesive layer is preferably 1 μm to 10 μm. The polarizing plate 100 can be attached to the organic EL panel body, for example, by means of an adhesive layer 40 disposed on the second main surface 10b side of the polarizing element 10. Although not shown, a release liner is actually attached to the surface of the adhesive layer 40. The release liner can be temporarily attached until the polarizing plate is ready for use. By using the release liner, the adhesive layer can be protected, and the polarizing plate can be rolled to form. The polarizing plate can be in the form of a strip or a single sheet. Here, "strip" refers to a long and thin shape with a length that is sufficiently long relative to its width, for example, a long and thin shape with a length that is more than 10 times, preferably more than 20 times, relative to its width. The strip-shaped polarizing plate can be rolled into a cylinder. A-1. Polarizing element The polarizing element described above is typically a film containing a dichroic substance (typically iodine). For example, from the perspective of thinness, the thickness of the polarizing element is preferably 15 μm or less, more preferably 12 μm or less, further preferably 10 μm or less, and especially preferably 8 μm or less. On the other hand, the thickness of the polarizing element is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 3 μm or more. The polarizing element preferably exhibits dichroism at any wavelength from 380 nm to 780 nm. The transmittance of a single element is, for example, 40.0% or more, preferably 41.5% or more, more preferably 43.0% or more, and even more preferably 44.5% or more. In polarizing elements with higher transmittance, the aforementioned decolorization problem may be more pronounced. On the other hand, the transmittance is, for example, 48.0% or less, possibly 46.0% or less, or possibly 45.0% or less. The polarization degree of the polarizing element is preferably 97.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more. The aforementioned monomer transmittance is representative of the Y value measured using a UV-Vis spectrophotometer and corrected for visual sensitivity. The aforementioned polarization is representative of the parallel transmittance Tp and orthogonal transmittance Tc measured using a UV-Vis spectrophotometer and corrected for visual sensitivity, and is calculated using the following formula: Polarization (%) = {(Tp - Tc) / (Tp + Tc)} 1 / 2 ×100 Polarizing elements can be manufactured by any suitable method. Specifically, polarizing elements can be made from a single layer of resin film or from a multilayer laminate of two or more layers. A representative method for manufacturing polarizing elements from the aforementioned single-layer resin film includes dyeing and stretching treatments of the resin film using dichroic substances such as iodine or dichroic dyes. For example, hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films can be used. The method may further include insolubility treatment, swelling treatment, and crosslinking treatment. This manufacturing method is well-known and commonly used in the industry, therefore detailed descriptions are omitted. The polarizing element obtained using the above-described laminate can be fabricated, for example, using a laminate of a resin substrate and a resin film or resin layer (typically a PVA-based resin layer). Specifically, it can be fabricated by: coating a PVA-based resin solution onto a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, thus obtaining a laminate of the resin substrate and the PVA-based resin layer; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizing element. In this embodiment, it is preferable to form a PVA-based resin layer comprising a halide and a PVA-based resin on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, stretching may, if necessary, include air-stretching the laminate at a high temperature (e.g., above 95°C) before stretching in the aqueous boric acid solution. Additionally, in this embodiment, it is preferable to subject the laminate to a drying shrinkage treatment, which involves heating it while conveying it along its length, causing it to shrink by 2% or more in its width direction. Typically, the manufacturing method of this embodiment includes sequentially performing an air-assisted stretching process, a dyeing process, an underwater stretching process, and a drying shrinkage process on the laminate. By introducing air-assisted stretching, even when PVA is coated on a thermoplastic resin, the crystallinity of PVA can be improved, resulting in higher optical properties. Furthermore, by simultaneously improving the alignment of PVA beforehand, problems such as reduced alignment or dissolution of PVA during immersion in water in subsequent dyeing or stretching steps can be prevented, resulting in higher optical properties. Moreover, when the PVA-based resin layer is immersed in a liquid, compared to the case where the PVA-based resin layer does not contain halides, the alignment disorder of PVA molecules and the reduction of alignment can be suppressed, resulting in higher optical properties. Furthermore, by using the drying shrinkage process to shrink the laminate in the width direction, higher optical properties can be achieved. A polarizing plate can be obtained by peeling off the release surface of the resin substrate from the obtained resin substrate / polarizing element laminate, or by applying an area layer protective layer on the opposite side of the release surface. Detailed descriptions of the manufacturing method of such polarizing element are provided, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. All descriptions in these publications are incorporated herein by reference. A-2. In one embodiment of the laminated film, as shown in FIG2, the laminated film 20 has a substrate (protective layer) 21 and a hard coating layer 22, and an intermediate layer 23 can be formed between the substrate 21 and the hard coating layer 22. In embodiments of the present invention, the polarizing plate is typically disposed on the viewing side of an organic EL display device, and the hard coating layer 22 is disposed closer to the viewing side than the substrate 21. The hard coating layer 22 can also function as, for example, an anti-reflective layer, an anti-sticking layer, an anti-glare layer, or other functional layers. The thickness of the laminated film is, for example, 15 μm or more and 70 μm or less, preferably 20 μm or more and 50 μm or less. The moisture permeability of the laminated membrane at 40°C and 92% RH is 600 g / m³. 2 • For temperatures below 24 hours, 550 g / m³ is preferred. 2 • For temperatures below 24 hours, 500 g / m³ is preferred. 2 • Less than 24 hours, and preferably 450 g / m 2 • Less than 24 hours. On the other hand, the moisture permeability of the laminated membrane at 40°C and 92%RH is preferably 300 g / m³. 2 • 24 hours or more, preferably 320 g / m 2 • 24 hours or more, preferably 340 g / m 2 ･24 hours or more. The optimal moisture permeability of the laminated membrane after humidification treatment is 800 g / m³ at 40°C and 92% RH. 2 • For temperatures below 24 hours, 700 g / m³ is preferred. 2 • Less than 24 hours, and preferably 600 g / m 2 • Less than 24 hours. The rate of change in moisture permeability caused by humidification treatment (moisture permeability after humidification treatment / moisture permeability before humidification treatment) is less than 1.5, preferably less than 1.4. Extremely high moisture resistance can be achieved by using this type of laminated film. Furthermore, the humidification treatment is, for example, performed by placing the laminated film at 65°C and 95%RH for 48 hours. The optimal moisture permeability of the laminated membrane after humidification treatment is 400 g / m³ at 40°C and 92% RH. 2 • 24 hours or more, preferably 450 g / m 2 • More than 24 hours, and preferably 500 g / m 2• 24 h or more. The rate of change in permeability caused by humidification treatment (permeability after humidification treatment / permeability before humidification treatment) is preferably 1.1 or more, more preferably 1.2 or more. By using this type of laminated film, discoloration can be suppressed. The inventors have discovered that when a polarizing plate is used in an organic EL display device, the main reason for the problem of discoloration of the polarizing plate is that ammonia (essentially ammonium ions) is easily generated in the components constituting the organic EL panel under high humidity conditions. By removing the ammonium ions that have penetrated into the polarizing plate (polarizing element), discoloration can be suppressed. Moreover, by arranging a component with higher permeability on one side of the polarizing element (typically the viewing side), discoloration can be suppressed. Specifically, the decomposition of dichroic substances (typically iodine complexes) contained in the polarizing element can be suppressed. The aforementioned substrate may include any suitable film that can be used as a protective layer for polarizing elements. Examples of materials constituting such a substrate (film) include: cellulose resins such as triacetyl cellulose (TAC); cyclic olefin resins such as polynorphine; polycarbonate resins; (meth)acrylic resins; polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); and polyolefin resins such as polyethylene. Cellulose resins such as triacetyl cellulose (TAC) are preferred as the material constituting the substrate. The thickness of the substrate is, for example, 10 μm or more and 65 μm or less, preferably 15 μm or more and 45 μm or less. The aforementioned hard coating is typically formed by applying a hard coating forming material to the aforementioned substrate and then curing the coating layer. The hard coating forming material typically includes a curing compound as a layer-forming component. Examples of curing mechanisms for the curing compound include thermosetting and photosetting types. Examples of curing compounds include monomers, oligomers, and prepolymers. It is preferable to use multifunctional monomers or oligomers as curing compounds. Examples of multifunctional monomers or oligomers include monomers or oligomers having two or more (meth)acrylic groups, oligomers of urethane (meth)acrylates or urethane (meth)acrylates, epoxy monomers or oligomers, and silicone monomers or oligomers. The aforementioned hard coating forming material may also contain any suitable additives. Examples of additives include: polymerization initiators, leveling agents, anti-blocking agents, dispersing stabilizers, thixotropic agents, antioxidants, UV absorbers, defoamers, tackifiers, dispersants, surfactants, catalysts, fillers, lubricants, and antistatic agents. The type, combination, and content of additives can be appropriately set according to the purpose or desired characteristics. When the curing compound is thermosetting, the heating temperature is, for example, 60°C to 140°C, preferably 60°C to 100°C. When the curing compound is photosetting, the curing process is typically carried out by ultraviolet (UV) irradiation. The cumulative UV irradiation intensity is, for example, 100 mJ / cm². 2 ~300 mJ / cm 2 It can also be combined with ultraviolet radiation and heating. The thickness of the hard coating is preferably 1 μm or more, more preferably 1.5 μm or more, and even more preferably 2 μm or more. This thickness prevents excessive moisture permeability of the laminated film. Furthermore, it ensures the scratch resistance of the resulting polarizing plate. On the other hand, the thickness of the hard coating is preferably 7 μm or less, more preferably 6 μm or less, and even more preferably 5 μm or less. This thickness satisfies the aforementioned moisture permeability requirements well, for example, suppressing discoloration. Moreover, scratch resistance can be evaluated, for example, by rubbing the hard coating surface with a cylinder bearing steel wool #0000 on its bottom surface under a load of 1.0 kg at a speed of approximately 100 mm per second for 1000 cycles, and then visually confirming the degree of damage to the hard coating surface. The aforementioned intermediate layer may contain components derived from the aforementioned substrate and components derived from the aforementioned hard coating layer. Specifically, the components forming the substrate and the components forming the hard coating layer can be compatible (mixed and coexisting) to form the film. For example, when the substrate contains TAC, components derived from the substrate may include TAC, acetic acid, and cellulose. In the laminated film, the interface between the intermediate layer and the substrate, and the interface between the intermediate layer and the hard coating layer, can be observed and confirmed by transmission electron microscopy (TEM). The thickness of the intermediate layer is, for example, more than 1 μm and less than 30 μm, preferably more than 1 μm and less than 20 μm, and even more preferably more than 1 μm and less than 10 μm. The ratio of the thickness of the hard coating layer to the thickness of the intermediate layer (thickness of the hard coating layer / thickness of the intermediate layer) is preferably 0.5 or more, and more preferably 0.6 or more. With this thickness ratio, for example, changes in the moisture permeability of the laminated film caused by humidification can be suppressed. On the other hand, the ratio of the thickness of the hard coating layer to the thickness of the intermediate layer (thickness of the hard coating layer / thickness of the intermediate layer) is preferably 1.0 or less, and more preferably 0.9 or less. With this thickness ratio, the aforementioned moisture permeability can be well satisfied, for example, suppressing discoloration. The intermediate layer can be formed, for example, by the presence of a solvent in the aforementioned hard coating forming material that is a good solvent capable of dissolving the substrate. Specifically, a portion of the components (representatively solvents) contained in the hard coating forming material is mixed with and / or penetrates into the substrate, forming a component of the substrate that is compatible with (mixed with) the component forming the hard coating, thus forming the intermediate layer. Solvents that may be contained in the aforementioned hard coating forming material include, for example: alcohols such as methanol, ethanol, isopropanol, butanol, TBA (tert-butyl alcohol), and 2-methoxyethanol; ketones such as acetone, MEK (methyl ethyl ketone), MIBK (methyl isobutyl ketone), and cyclopentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, and PMA (propylene glycol monomethyl ether acetate); ethers such as diisopropyl ether and propylene glycol monomethyl ether; diols such as ethylene glycol and propylene glycol; cellosolvers such as ethyl cellosolvers and butyl cellosolvers; aliphatic hydrocarbons such as hexane, heptane, and octane; and aromatic hydrocarbons such as benzene, toluene, and xylene. One of these solvents may be used alone, or two or more may be used in combination. The solvent content is set such that the concentration of the solids component of the aforementioned hard coating forming material is, for example, 20% by weight or more and 50% by weight or less, preferably 30% by weight or more and 45% by weight or less. As a good solvent for dissolving the aforementioned substrate, a solvent in which the amount of substrate (solute) dissolved is 30 parts by weight or more per 100 parts by weight of solvent is used. As a specific example, when the substrate contains TAC, a good solvent for dissolving the substrate is preferably cyclopentanone (e.g., the amount of TAC dissolved is 40 parts by weight per 100 parts by weight of cyclopentanone), MEK (e.g., the amount of TAC dissolved is 60 parts by weight per 100 parts by weight of MEK), cyclohexanone, methyl acetate, or ethyl acetate. In one embodiment, the hard coating forming material comprises a good solvent that can dissolve the substrate and a poor solvent that substantially does not dissolve the substrate. As a poor solvent that substantially does not dissolve the substrate, for example, a solvent in which the amount of substrate (solute) dissolved is less than 30 parts by weight relative to 100 parts by weight of the solvent is used; more preferably, a solvent in which the amount of substrate (solute) dissolved is less than 10 parts by weight relative to 100 parts by weight of the solvent is used. When the substrate contains TAC, ethanol, isopropanol, or hexane are preferred examples of poor solvents that substantially do not dissolve the substrate. The ratio of the content of the good solvent that can dissolve the substrate to the content of the poor solvent that substantially does not dissolve the substrate in the hard coating forming material (content of good solvent / content of poor solvent, weight ratio) is, for example, 1.5 or less, preferably 0.3 to 1.2 or less, and more preferably 0.4 to 1.1 or less. A-3. Phase Retardation Layer As described above, the phase retardation layer can be a single layer as shown in the figure, or it can have a multilayer structure with two or more layers. In the case where the phase retardation layer is a single layer, it typically functions as a λ / 4 plate. The phase retardation layer is typically provided to impart anti-reflective properties to organic EL display devices. Regarding the phase retardation layer, the refractive index characteristics typically exhibit a relationship of nx > ny = nz. The in-plane phase difference Re(550) of the phase retardation layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and even more preferably 120 nm to 160 nm. Furthermore, here, "ny = nz" includes not only the case where ny and nz are exactly equal, but also the case where they are substantially equal. Specifically, sometimes ny > nz or ny < nz. The Nz coefficient of the phase retardation layer is preferably 0.9 to 1.5, more preferably 0.9 to 1.3. By satisfying this relationship, an organic EL display device with excellent reflective hue can be obtained. When the retardation layer is a single layer, it is preferable that the retardation layer exhibits inverse wavelength dispersion characteristics, where the phase difference value increases according to the wavelength of the measured light. In this case, the Re(450) / Re(550) of the retardation layer is preferably 0.8 or higher and less than 1, more preferably 0.8 or higher and less than 0.95. With this configuration, very excellent anti-reflection properties can be achieved. The angle between the slow axis of the retardation layer and the absorption axis of the polarizing element is preferably 40° to 50°, more preferably 42° to 48°, and even more preferably about 45°. If the angle is within this range, an organic EL display device with excellent anti-reflective properties can be obtained by using the retardation layer as a λ / 4 plate as described above. The phase retardation layer has a moisture permeability of 200 g / m² at 40°C and 92%RH. 2 • For temperatures below 24 hours, the optimal concentration is 150 g / m³. 2 • For temperatures below 24 hours, 100 g / m³ is preferred. 2 • Less than 24 hours. This retardation layer functions as a barrier layer to block the penetration of ammonia (ammonium ions) into the polarizing element, thus helping to suppress discoloration. Specifically, if the moisture permeability of the aforementioned laminated film is too high, it is sometimes difficult to ensure extremely high moisture resistance. Therefore, by combining this barrier layer, extremely high moisture resistance can be ensured, and discoloration can be significantly suppressed. On the other hand, the moisture permeability of the retardation layer at 40°C and 92%RH is, for example, 50 g / m³. 2 • More than 24 hours. Furthermore, when the retardation layer has a multilayered structure with two or more layers, the moisture permeability of the retardation layer refers to the moisture permeability of the multilayered structure that may include the bonding layer. The retardation layer may comprise any suitable material, as long as it satisfies the characteristics described above. Specifically, the retardation layer may be a resin film (an extended resin film) or an alignment and curing layer of a liquid crystal compound (a liquid crystal alignment and curing layer). Preferably, the retardation layer comprises a resin film (an extended resin film). In this case, the thickness of the retardation layer is preferably 10 μm or more and 70 μm or less, more preferably 20 μm or more and 60 μm or less. Representative examples of resins constituting resin films include polycarbonate resins or polyester carbonate resins (hereinafter sometimes simply referred to as polycarbonate resins). Any suitable polycarbonate resin can be used as a polycarbonate resin, as long as the desired moisture permeability is achieved. For example, a polycarbonate resin may contain structural units derived from benzoyl dihydroxy compounds; structural units derived from isosorbide dihydroxy compounds; and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic diethanols, di-, tri-, or polyethylene glycols, and alkyl diols or spirodiols. The polycarbonate resin preferably comprises structural units derived from genus dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from alicyclic diethanol and / or structural units derived from di, tri, or polyethylene glycol; more preferably, it comprises structural units derived from genus dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from di, tri, or polyethylene glycol. The polycarbonate resin may also, as needed, comprise structural units derived from other dihydroxy compounds. The retardation layer can be formed by stretching a film comprising the polycarbonate resin described above under any suitable stretching conditions. Furthermore, detailed descriptions of the polycarbonate resin and the method for forming the retardation layer are provided, for example, in Japanese Patent Application Publication Nos. 2014-10291, 2014-26266, 2015-212816, 2015-212817, 2015-212818, 2017-54093, and 2018-60014. These publications are incorporated herein by reference. A-4. The thickness of the other adhesive layer 40 is preferably 10 μm to 20 μm. The adhesive layer may contain any suitable adhesive. Specific examples include: acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, carbamate adhesives, epoxy adhesives, and polyether adhesives. By adjusting the type, quantity, combination, and mixing ratio of monomers in the matrix resin forming the adhesive, as well as the amount of crosslinking agent, reaction temperature, and reaction time, an adhesive with desired properties corresponding to the purpose can be prepared. The matrix resin of the adhesive can be used alone or in combination of two or more. The matrix resin is preferably an acrylic resin (specifically, the adhesive layer preferably contains an acrylic adhesive). B. Organic EL Display Device The aforementioned polarizing plate can be used in an organic EL display device. Therefore, the organic EL display device according to an embodiment of the present invention includes the aforementioned polarizing plate. Figure 3 is a schematic cross-sectional view showing the state in which a polarizing plate is disposed on an organic EL panel in an organic EL display device according to one embodiment of the present invention. The polarizing plate (polarizing plate with phase retardation layer) 100 is disposed in the organic EL panel 200 such that the polarizing element 10 is closer to the organic EL panel body 70 than the laminated film 20. Specifically, the polarizing plate 100 is attached to the organic EL panel body 70 by means of an adhesive layer 40. The organic EL panel body 70 has a substrate 71 and an upper structural layer 72, which includes: a circuit layer containing thin-film transistors (TFTs), an organic light-emitting diode (OLED), and a sealing film for sealing the OLED. For example, when a flexible substrate (e.g., a resin substrate) is used as the substrate 71, the resulting organic EL display device can be bent, flexed, folded, and rolled. The upper structural layer 72 includes, for example, a nitrogen-containing layer (e.g., silicon nitride, silicon oxynitride, or other nitride layers), from which ammonia (ammonium ions) can be generated. According to the above-described polarizing plate, color fading can be suppressed in the organic EL display device. Furthermore, the color fading problem can be solved without designing changes to the structure of the organic EL panel body. [Example] The present invention will now be specifically described by way of examples, but the present invention is not limited to these examples. The methods for measuring thickness and moisture permeability are as follows. Furthermore, unless otherwise explicitly stated, "parts" and "%" in the examples and comparative examples are based on weight. 1. Thicknesses of 10 μm or less were measured using an interferometric film thickness gauge (manufactured by Otsuka Electronics Co., Ltd., product name "MCPD-3000"). Thicknesses exceeding 10 μm were measured using a digital micrometer (manufactured by Hikari Co., Ltd., product name "KC-351C"). 2. Moisture permeability was determined using the cup method (JIS Z 0208). [Example 1] (Fabrication of Polarizing Element) As a thermoplastic resin substrate, a strip-shaped amorphous polyethylene terephthalate (PET) copolymer with a water absorption rate of 0.75% and a Tg of approximately 75°C (thickness: 100 μm) was used. One side of the resin substrate was subjected to corona treatment. 13 parts by weight of potassium iodide were added to 100 parts by weight of a PVA-based resin prepared by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetyl acetylated modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z410") in a 9:1 weight ratio. The resulting solution was dissolved in water to prepare a PVA aqueous solution (coating solution). The PVA aqueous solution was coated onto the corona-treated side of the resin substrate and dried at 60°C to form a 13 μm thick PVA-based resin layer, thus fabricating a laminate. The resulting laminate was uniaxially stretched 2.4 times its original length along its free end in a 130°C oven between rollers at different circumferential speeds (air-assisted stretching treatment). Next, the laminate was immersed in an insoluble bath (a boric acid aqueous solution prepared by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at 40°C for 30 seconds (insoluble treatment). Then, it was immersed in a dyeing bath (an iodine aqueous solution prepared by mixing iodine and potassium iodide in a 1:7 weight ratio with 100 parts by weight of water) at 30°C, adjusting the concentration to achieve a final polarizing element transmittance (Ts) of 43.0%, and for 60 seconds (dyeing treatment). Finally, it was immersed in a crosslinking bath (a boric acid aqueous solution prepared by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) at 40°C for 30 seconds (crosslinking treatment). Subsequently, the laminate was immersed in a boric acid aqueous solution (4.0 wt% boric acid and 5.0 wt% potassium iodide) at 70°C, and simultaneously uniaxially stretched along the longitudinal direction (length direction) between rollers with different circumferential speeds at a total elongation ratio of 5.5 times (underwater stretching treatment). Then, the laminate was immersed in a cleaning bath at 20°C (an aqueous solution of 4 wt% potassium iodide to 100 wt% water) (cleaning treatment). Afterward, it was dried in an oven maintained at 90°C, and contacted with SUS heated rollers with a surface temperature maintained at 75°C for approximately 2 seconds (drying shrinkage treatment). The width shrinkage rate of the laminate obtained by the drying shrinkage treatment was 5.2%. Thus, a polarizing element with a thickness of 5 μm was formed on a resin substrate. (Preparation of Hard Coating Forming Material) 50 parts by weight of UV-curable acrylic resin (manufactured by DIC Corporation, trade name "LUXYDIR 17-806", solids content 80%) were prepared. For every 100 parts by weight of the resin's solids content, 3 parts by weight of a photopolymerization initiator (manufactured by IGM Resins, trade name "OMNIRAD907") and 0.05 parts by weight of a leveling agent (manufactured by DIC Corporation, trade name "GRANDIC PC4100", solids content 10%) were mixed to obtain a mixture. The obtained mixture was diluted using a mixed solvent prepared by mixing isopropanol (IPA) and cyclopentanone (CPN) in a weight ratio of 65:35 to achieve a solids content concentration of 36%, thereby preparing the hard coating forming material. (Fabrication of the laminated film) The obtained hard coating forming material (coating liquid) was coated onto a 25 μm thick TAC film (manufactured by Konica Minolta, Inc., trade name "KC2UA") using a bar coater. After drying the coated TAC film by heating it at 80°C for 1 minute, it was irradiated with a high-pressure mercury lamp with a cumulative light intensity of 300 mJ / cm². 2 The coating is hardened by ultraviolet light, resulting in a thickness of 32 μm and a moisture permeability of 440 g / m² at 40°C and 92% RH. 2 ･24 h stacked membrane. (Fabrication of the phase difference layer 1) Polymerization was carried out using a batch polymerization apparatus comprising two vertical reactors equipped with stirring blades and a reflux cooler controlled at 100°C. 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)furan-9-yl]methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB), 42.28 parts by mass (0.139 mol) of spirodiol (SPG), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10⁻⁶ mol of calcium acetate monohydrate as a catalyst were added. -2 Parts by weight (6.78 × 10) -5(mol). After purging the reactor with nitrogen under reduced pressure, it is heated by a heat transfer medium, and stirring begins when the internal temperature reaches 100°C. Forty minutes after the start of heating, the internal temperature is raised to 220°C and maintained at this temperature. Simultaneously, pressure is reduced, and after reaching 220°C, it is maintained at 13.3 kPa for 90 minutes. Phenol vapor, a byproduct of the polymerization reaction, is introduced into a 100°C reflux cooler, allowing some monomer components contained in the phenol vapor to return to the reactor. Non-condensable phenol vapor is introduced into a 45°C condenser and recovered. Nitrogen is introduced into reactor 1, and after temporarily restoring the pressure to atmospheric pressure, the oligomerized reaction liquid in reactor 1 is transferred to reactor 2. Then, heating and depressurization are initiated in reactor 2, maintaining an internal temperature of 240°C and a pressure of 0.2 kPa for 50 minutes. Polymerization then proceeds until the specified stirring power is achieved. Nitrogen gas is introduced into the reactor at the specified time point to repressurize it, and the generated polyester carbonate resin is extruded into water and cut into granules. The obtained polyester carbonate resin (granules) was vacuum dried at 80°C for 5 hours. Then, a film-forming apparatus equipped with a single-spindle extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250°C), a T-die (width 200 mm, set temperature: 250°C), a cooling roller (set temperature: 120–130°C), and a winding machine was used to produce a strip resin film with a thickness of 135 μm. The obtained strip resin film was then stretched in the width direction at a stretching temperature of 143°C and a stretch ratio of 2.8 times to obtain a thickness of 47 μm and a moisture permeability of 75 g / m² at 40°C and 92% RH. 2 • 24 h of extended film. The obtained extended film has a Re(550) of 147 nm, a Re(450) / Re(550) of 0.86, and an Nz coefficient of 1.12. (Fabrication of the Polarizing Plate) The obtained composite film is bonded to the surface of the polarizing element in the resin substrate / polarizing element laminate obtained above using a UV-curable adhesive (cured thickness: 1.0 μm). Next, the resin substrate is peeled off from the polarizing element, and the obtained retardation layer (extended film) is bonded to the peeled surface through a 5 μm thick acrylic adhesive layer. At this time, the bonding is performed at a 45° angle between the absorption axis of the polarizing element and the slow axis of the retardation layer. Then, a 15 μm thick adhesive layer is formed on the surface of the retardation layer using an acrylic adhesive, resulting in the polarizing plate. [Example 2] In the preparation of the hard coating forming material, except that a mixed solvent of IPA and CPN was used in a weight ratio of 50:50, a polarizing plate was obtained in the same manner as in Example 1. Furthermore, the thickness of the resulting laminated film was 33 μm, and the moisture transmittance at 40°C and 92% RH was 380 g / m². 2 ･24 h. [Examples 3 and 4] Polarizing plates were obtained in the same manner as in Examples 1 and 2, except that the film constituting the retardation layer was fabricated using the method described below. Furthermore, the thickness of the resulting extended film was 37 μm, and the moisture transmittance at 40°C and 92% RH was 105 g / m². 2 ･24 h, Re(550) is 144 nm, Re(450) / Re(550) is 0.86, and Nz coefficient is 1.09. (Fabrication of the film constituting the phase difference layer 2) Except for melt-blending 0.7 parts by weight of acrylic resin (PMMA), polyester carbonate resin (granules) was obtained in the same manner as in Example 1. After vacuum drying at 80°C for 5 hours, a strip resin film with a thickness of 105 μm was produced using a film forming apparatus equipped with a single-spindle extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250°C), a T-die (width 200 mm, set temperature: 250°C), a cooling roller (set temperature: 120-130°C), and a winding machine. The obtained strip resin film was stretched in the width direction at a stretching temperature of 138°C and a stretch ratio of 2.8 times to obtain a stretched film. [Comparative Example 1] In the preparation of the hard coating forming material, except that a mixed solvent of IPA and CPN was used at a weight ratio of 30:70, a polarizing plate was obtained in the same manner as in Example 1. Furthermore, the thickness of the resulting laminated film was 33 μm, and the moisture transmittance at 40°C and 92%RH was 380 g / m². 2 ･24 h. [Comparative Example 2] In the preparation of the hard coating forming material, except that a mixed solvent of IPA and CPN was used at a weight ratio of 20:80, a polarizing plate was obtained in the same manner as in Example 1. Furthermore, the thickness of the resulting laminated film was 33 μm, and the moisture transmittance at 40°C and 92% RH was 380 g / m². 2 ･24 h. [Comparative Example 3] In the preparation of the hard coating forming material, except that a mixed solvent of IPA and CPN was used at a weight ratio of 10:90, a polarizing plate was obtained in the same manner as in Example 1. Furthermore, the thickness of the resulting laminated film was 33 μm, and the moisture transmittance at 40°C and 92% RH was 380 g / m². 2 ･24 h. [Comparative Example 4] In the preparation of the hard coating forming material, except that a mixed solvent of IPA and CPN was used at a weight ratio of 30:70, the polarizing plate was obtained in the same manner as in Example 3. Furthermore, the thickness of the resulting laminated film was 33 μm, and the moisture transmittance at 40°C and 92% RH was 380 g / m². 2 ･24 h. [Comparative Example 5] In the preparation of the hard coating forming material, except that a mixed solvent of IPA and CPN was used at a weight ratio of 20:80, a polarizing plate was obtained in the same manner as in Example 3. Furthermore, the thickness of the resulting laminated film was 33 μm, and the moisture transmittance at 40°C and 92% RH was 380 g / m². 2 ･24 h. [Comparative Example 6] In the preparation of the hard coating forming material, except that a mixed solvent of IPA and CPN was used at a weight ratio of 10:90, a polarizing plate was obtained in the same manner as in Example 3. Furthermore, the thickness of the resulting laminated film was 33 μm, and the moisture transmittance at 40°C and 92%RH was 380 g / m². 2 ･24 h. [Comparative Examples 7 and 8] Polarizing plates were obtained in the same manner as in Examples 1 and 2, except that the liquid crystal alignment and curing layer shown below was used as a phase retardation layer. (Preparation of the liquid crystal alignment curing layer constituting the phase retardation layer) 55 parts of the compound represented by formula (I), 25 parts of the compound represented by formula (II), and 20 parts of the compound represented by formula (III) were added to 400 parts of cyclopentanone (CPN). The mixture was heated to 60°C and stirred until dissolved. After confirming dissolution, the mixture was allowed to return to room temperature. Then, 3 parts of Irgacure 907 (manufactured by BASF Japan Co., Ltd.), 0.2 parts of MEGAFAC F-554 (manufactured by DIC Co., Ltd.), and 0.1 parts of p-methoxyphenol (MEHQ) were added, and the mixture was stirred to obtain a solution. The solution was transparent and homogeneous. The obtained solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. On the other hand, the alignment membrane polyimide solution was coated onto a 0.7 mm thick glass substrate using spin coating. The coating was dried at 100°C for 10 minutes and calcined at 200°C for 60 minutes to obtain a coating film. The obtained coating was subjected to a friction treatment to form an alignment film. The friction treatment was performed using a commercially available friction device. The polymeric composition obtained above was coated onto a substrate (essentially an alignment film) by spin coating and dried at 100°C for 2 minutes. After the obtained coating film was cooled to room temperature, it was subjected to a high-pressure mercury lamp at 30 mW / cm². 2 A liquid crystal alignment and curing layer was obtained by irradiating the layer with ultraviolet light at an intensity of 30 seconds. The thickness of the obtained liquid crystal alignment and curing layer was 3 μm, and the moisture permeability at 40℃ and 92%RH was 815 g / m². 2 ･24 h, the in-plane phase difference Re(550) is 130 nm, and Re(450) / Re(550) is 0.851. [Chemistry 1] [Chemistry 2] [Comparative Examples 9, 10 and 11] except that the liquid crystal alignment and curing layer described above was used as a phase retardation layer, polarizing plates were obtained in the same manner as in Comparative Examples 1, 2 and 3. The following evaluations were conducted on the examples and comparative examples. The evaluation results are summarized in Table 1. <Evaluation> 1. Structure of the laminated film: The cross-section of the obtained laminated film was observed using a transmission electron microscope (TEM) (magnification: 10000x) to confirm the laminated structure and measure the thickness of the layer on the TAC film (substrate). 2. Changes in the moisture transmittance of the laminated film: The obtained laminated film was placed at 65°C and 95%RH for 48 hours (humidification treatment). The moisture transmittance of the laminated film after humidification treatment was measured at 40°C and 92%RH. 3. Changes in transmittance 1 (ammonia decolorization): The obtained polarizing plate was laminated onto an alkali-free glass plate with a 500 nm thick silicon oxynitride film on its surface, and then placed at 65°C and 95%RH for 48 hours (humidification test). The transmittance Ts of the polarizing plate before and after the humidification test was measured using a UV-Vis spectrophotometer ("LPF-2000" manufactured by Otsuka Electronics Co., Ltd.), and the transmittance change ΔTs was calculated (ΔTs = Ts after humidification test - Ts before humidification test). Furthermore, the generation of ammonia was confirmed by subjecting an alkali-free glass plate with a silicon oxynitride film to a humidification test. 4. Transmittance Change 2 (Moisture Resistance) The obtained polarizing plate was bonded to an alkali-free glass plate and placed in an environment of 65°C and 95%RH for 336 hours (humidification test). The transmittance Ts of the polarizing plate before and after the humidification test was measured using a UV-Vis spectrophotometer ("LPF-2000" manufactured by Otsuka Electronics Co., Ltd.), and the transmittance change ΔTs was calculated (ΔTs = Ts after humidification test - Ts before humidification test). [Table 1] In all embodiments and comparative examples, the formation of the intermediate layer was confirmed by TEM observation. In all embodiments, the transmittance variation ΔTs was confirmed to be within ±3%. [Industrial Applicability] The polarizing plate of the present invention is suitable for use in organic EL display devices, for example. 10: Polarizing element; 10a: First main surface; 10b: Second main surface; 20: Lamination film; 21: Substrate; 22: Hard coating; 23: Intermediate layer; 30: Phase retardation layer; 40: Adhesive layer; 70: Organic EL panel body; 71: Substrate; 72: Upper structural layer; 100: Polarizing plate; 200: Organic EL panel Figure 1 is a schematic cross-sectional view showing the general configuration of a polarizing plate according to one embodiment of the present invention. Figure 2 is a cross-sectional view showing an example of the general configuration of the multilayer film of the polarizing plate shown in Figure 1. Figure 3 is a schematic schematic cross-sectional view showing the state in which the polarizing plate is disposed on an organic EL panel in an organic EL display device according to one embodiment of the present invention. 10: Polarizing element 10a: First Main Face 10b: Second Main Page 20: Stacked membrane 30: Phase Difference Layer 40: Adhesive layer 100:Polarizing plate

Claims

1. A polarizing plate comprising: a polarizing element having a first main surface and a second main surface facing each other; a laminated film disposed on the first main surface side of the polarizing element and sequentially comprising a substrate and a hard coating layer from the polarizing element side; and a retardation layer disposed on the second main surface side of the polarizing element; wherein the moisture permeability of the laminated film is 600 g / m²·24 h or less, the moisture permeability change rate of the laminated film obtained by placing the laminated film in an environment of 65°C and 95%RH for 48 hours is 1.1 to 1.5 or less, and the moisture permeability of the retardation layer is 200 g / m²·24 h or less.

2. The polarizing plate of claim 1, wherein the thickness of the aforementioned hard coating is 1 μm or more.

3. The polarizing plate of claim 1 or 2, wherein the thickness of the aforementioned hard coating is less than 7 μm.

4. The polarizing plate of claim 1 or 2, wherein the laminated film includes an intermediate layer between the substrate and the hard coating, the intermediate layer comprising components derived from the substrate and components derived from the hard coating.

5. The polarizing plate of claim 1 or 2, wherein the phase difference layer is disposed adjacent to the polarizing element.

6. The polarizing plate of request item 1 or 2, wherein the Re(450) / Re(550) of the aforementioned phase difference layer is 0.8 or higher but less than 1.

7. The polarizing plate of claim 1 or 2, wherein the transmittance of a single polarizing element is 43.0% or more.

8. The polarizing plate of claim 1 or 2, wherein the thickness of the polarizing element is less than 10 μm.

9. An organic electroluminescent display device having a polarizing plate as claimed in any one of claims 1 to 8.

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