Polarizing plate with phase difference layer and organic electroluminescent display device using same

Abstract

Provided is a polarizing plate with a phase difference layer, which can significantly suppress decoloring when applied to an organic EL display device. A polarizing plate with a phase difference layer according to an embodiment of the present invention has a polarizer and a barrier layer that is disposed on one side of the polarizer and includes a phase difference layer, the barrier layer having an ammonia gas transmission amount of 70 g / m2 * 24 h or less.

Description

[0001] This application is a divisional application of Chinese national application number 202180078043.X, filed on July 28, 2021, entitled "Polarizer with Phase Difference Layer and Organic Electroluminescent Display Device Using the Same". Technical Field

[0002] This invention relates to a polarizer with a phase retardation layer and an organic electroluminescent (EL) display device using the same. Background Technology

[0003] In recent years, with the popularization 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 and background reflection. Therefore, it is known to prevent these problems by placing a circular polarizer on the viewable side (e.g., Patent Document 1 and Patent Document 2). However, the circular polarizer placed in the organic EL display device is prone to color fading.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2002-372622 Patent Document 2: Japanese Patent No. 3325560 Summary of the Invention

[0005] The problem that the invention aims to solve The present invention was made to solve the above-mentioned prior art problems, and its main objective is to provide a polarizer with a phase retardation layer that can significantly suppress discoloration when applied to organic EL display devices.

[0006] Methods for solving problems According to an embodiment of the present invention, a polarizer with a phase retardation layer is provided. The polarizer with a phase retardation layer has a polarizer and a blocking layer, the blocking layer being disposed on one side of the polarizer and comprising the phase retardation layer, wherein the ammonia permeation rate of the blocking layer is 70 g / m³. 2 • Less than 24 hours.

[0007] In one embodiment, the ammonia permeation rate of the aforementioned phase retardation layer is 70 g / m². 2 • Less than 24 hours.

[0008] In one embodiment, the blocking layer comprises a protective layer for the polarizer.

[0009] In one embodiment, the ammonia permeation rate of the above-mentioned protective layer is 70 g / m³. 2 • Less than 24 hours.

[0010] In one embodiment, the polarizer with the phase difference layer has a protective layer disposed on the other side of the polarizer.

[0011] In one embodiment, the transmittance of the polarizer is 40% or more and 45% or less.

[0012] In one embodiment, the Re(450) / Re(550) of the aforementioned phase difference layer is greater than 0.8 and less than 1.

[0013] In one embodiment, the thickness of the polarizer is less than 10 μm.

[0014] In one embodiment, the thickness of the polarizer with the phase retardation layer is less than 150 μm.

[0015] According to another aspect of the present invention, an organic electroluminescent display device is provided. This organic electroluminescent display device has the aforementioned polarizer with a phase retardation layer.

[0016] Invention Effects According to an embodiment of the present invention, in a polarizer with a phase retardation layer, by providing a layer on one side of the polarizer that satisfies a specified ammonia permeation amount, a polarizer with a phase retardation layer that can significantly suppress discoloration when applied to an organic EL display device can be realized. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view showing the general configuration of a polarizer with a phase difference layer according to one embodiment of the present invention.

[0018] Figure 2 This is a schematic cross-sectional view showing a state in which a polarizer with a phase retardation layer is disposed on an organic EL panel in an organic EL display device according to one embodiment of the present invention. Detailed Implementation

[0019] The embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

[0020] (Definitions of terms and symbols) The definitions of terms and symbols used in this specification are as follows.

[0021] (1) Refractive index (nx, ny, nz) “nx” is the refractive index in the direction where the refractive index is maximum (i.e., the slow axis direction), “ny” is the refractive index in the direction orthogonal to the slow axis (i.e., the fast axis direction), and “nz” is the refractive index in the thickness direction.

[0022] (2) In-plane phase difference (Re) “Re(λ)” is the in-plane phase difference measured at 23°C using light with a wavelength of λ nm. For example, “Re(550)” is the in-plane phase difference measured at 23°C using light with a wavelength of 550 nm. When the thickness of the layer (film) is set to d (nm), Re(λ) is obtained by the formula: Re(λ) = (nx - ny) × d.

[0023] (3) Phase difference in the thickness direction (Rth) “Rth(λ)” is the phase difference in the thickness direction measured by light with a wavelength of λ nm at 23°C. For example, “Rth(550)” is the phase difference in the thickness direction measured by light with a wavelength of 550 nm at 23°C. When the thickness of the layer (film) is set to d (nm), Rth(λ) is obtained by the formula: Rth(λ) = (nx - nz) × d.

[0024] (4) Nz coefficient The Nz coefficient is obtained by Nz=Rth / Re.

[0025] (5) Angle When an angle is mentioned in this specification, the angle includes both clockwise and counterclockwise relative to a reference direction. Therefore, for example, "45°" means ±45°.

[0026] A. Polarizer with phase retardation layer Figure 1 This is a schematic cross-sectional view showing the general configuration of a polarizer with a phase retardation layer according to one embodiment of the present invention. The polarizer 100 with a phase retardation layer includes a polarizer 11, a protective layer (viewable side protective layer) 12 disposed on the visible side of the polarizer 11, and a blocking layer 30 disposed on the side of the polarizer 11 opposite to the visible side. The blocking layer 30 sequentially includes the protective layer (inner protective layer) 13 of the polarizer 11 and the phase retardation layer 20 from the visible side. Thus, the protective layer 13 is disposed on the side of the polarizer 11 opposite to the visible side, but the protective layer 13 may be omitted depending on the purpose, etc. Specifically, the blocking layer 30 may also not include the protective layer 13. For example, if the phase retardation layer 20 is a stretched film of a resin film and can also serve as a protective layer for the polarizer, the protective layer 13 may be omitted. On the other hand, if the phase retardation layer 20 is an alignment-cured layer of a liquid crystal compound, the protective layer 13 is typically disposed. The phase retardation layer 20 can be a single layer or a stacked structure consisting of two or more layers. It should be noted that the stack of the polarizer and the protective layer is referred to as a polarizer. In the example shown, the polarizer 10 has a polarizer 11 and protective layers 12 and 13.

[0027] The thickness of the polarizer with a retardation layer (the thickness from the visible side protective layer to the retardation layer) is preferably 150 μm or less, more preferably 120 μm or less, even more preferably 100 μm or less, and particularly preferably 80 μm or less. The lower limit of the thickness of the polarizer with a retardation layer is preferably 20 μm, more preferably 45 μm. Such a polarizer with a retardation layer can, for example, have excellent flexibility and bending durability. As a result, the polarizer with a retardation layer can be applied to organic EL display devices that are flexible, bendable, foldable, and rollable.

[0028] Although not illustrated, a polarizer with a phase retardation layer can further have other functional layers. The type, characteristics, number, combination, and configuration of the functional layers that a polarizer with a phase retardation layer can have can be appropriately set according to the purpose. For example, a polarizer with a phase retardation layer can further have a conductive layer or an isotropic substrate with a conductive layer. A polarizer with a phase retardation layer having a conductive layer or an isotropic substrate with a conductive layer can be applied, for example, to an organic EL display device in which a touch sensor is incorporated inside an organic EL panel. As another example, a polarizer with a phase retardation layer can further have other phase retardation layers. The optical characteristics (e.g., refractive index characteristics, in-plane phase difference, Nz coefficient, photoelastic coefficient), thickness, and configuration of other phase retardation layers can be appropriately set according to the purpose. As a specific example, other phase retardation layers (representatively, layers that impart (elliptical) polarization function or layers that impart ultra-high phase difference) can also be provided on the visible side of the polarizer 10 to improve visibility when viewed through polarized sunglasses. By having such layers, excellent visibility can be achieved even when viewing the display image through polarized lenses such as polarized sunglasses. Therefore, the resulting polarizer (polarizer with phase difference layer) is also suitable for use in image display devices that can be used outdoors.

[0029] The components constituting the polarizer with the phase retardation layer can be laminated via any suitable adhesive layer (not shown). Specific examples of adhesive layers include adhesive layers and bonding agents. Specifically, the phase retardation layer 20 can be attached to the polarizer 11 or the protective layer 13 via an adhesive layer (preferably using an active energy radiation-curing adhesive), or via an adhesive layer (e.g., an acrylic adhesive). When the phase retardation layer 20 has a laminated structure with two or more layers, each phase retardation layer is attached, for example, via an adhesive layer (preferably using an active energy radiation-curing adhesive). The blocking layer 30 may also include an adhesive layer disposed between the polarizer 11 and the phase retardation layer 20.

[0030] Although not illustrated, in practical applications, an adhesive layer is provided on the side of the phase retardation layer 20 opposite to the side where the polarizer 11 is disposed (specifically, as the outermost layer opposite to the visible side), and the polarizer with the phase retardation layer is made to be attached to the organic EL panel body. Furthermore, a release film (sealant) is preferably temporarily attached to the surface of the adhesive layer before the polarizer with the phase retardation layer is supplied for use. By temporarily attaching the release film, the adhesive layer can be protected, and a roll of the polarizer with the phase retardation layer can be formed.

[0031] The polarizer with the phase retardation layer can be in the form of a strip or a single sheet. Here, "strip" refers to a long, thin shape with a length that is sufficiently long relative to its width, for example, a long, thin shape with a length that is 10 times or more, preferably 20 times or more, than its width. The strip-shaped polarizer with the phase retardation layer can be wound into a roll.

[0032] A-1. Barrier Layer The ammonia permeation rate through barrier layer 30 is 70 g / m². 2 • Less than 24 hours, preferably 60g / m 2 • Less than 24 hours, preferably 50g / m 2 • Less than 24 hours, preferably 40g / m 2 • Less than 24 hours, preferably 30g / m 2 • Less than 24 hours. By setting such a blocking layer, discoloration can be significantly suppressed. The inventors directly addressed the new problem of discoloration of polarizers with phase retardation layers when applying them to organic EL display devices. Through in-depth research, they discovered that the discoloration is caused by ammonia (essentially ammonium ions) in the components constituting the organic EL panel. By using such a blocking layer 30 to block ammonia from reaching the polarizer 11 as much as possible, discoloration can be significantly suppressed. Specifically, the decomposition of dichroic substances (typically iodine complexes) contained in the polarizer can be suppressed. The ammonia permeation rate of the blocking layer 30 is, for example, 3.0 g / m³. 2 ·More than 24h.

[0033] The ammonia permeation rate of the barrier layer 30 can be achieved by at least one layer contained in the barrier layer 30, or by a combination of two or more layers contained in the barrier layer 30. Specifically, the ammonia permeation rate of the barrier layer 30 can be achieved by the protective layer 13 of the polarizer 11, by the phase retardation layer 20, by the aforementioned adhesive layer (e.g., an adhesive layer), or by a combination of these. In one embodiment, the ammonia permeation rate of either or both of the phase retardation layer 20 and the protective layer 13 is 70 g / m³. 2 • Less than 24 hours.

[0034] The ammonia permeation rate mentioned above can be determined by measuring the permeation rate of ammonia solution and water, and the difference between them can be used to calculate the permeation rate.

[0035] A-2. Polarizer The polarizer described above is typically a membrane containing a dichroic substance (typically iodine).

[0036] For example, from the viewpoint of thinness, the thickness of the polarizer is preferably 15 μm or less, more preferably 12 μm or less, even more preferably 10 μm or less, and particularly preferably 8 μm or less. On the other hand, the thickness of the polarizer is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more. If the thickness of the polarizer is within such a range, for example, curling during heating can be well suppressed, and good appearance durability during heating can be obtained.

[0037] The polarizer preferably exhibits absorption dichroism at any wavelength from 380 nm to 780 nm. The transmittance of a single element in the polarizer 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. Alternatively, the transmittance may be, for example, 46.0% or less, or possibly 45.0% or less. The polarization degree of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more.

[0038] The polarizer can be manufactured by any suitable method. Specifically, the polarizer can be made from a single layer of resin film or from a laminate of two or more layers.

[0039] A typical method for manufacturing a polarizer from the aforementioned single-layer resin film includes dyeing the resin film with a dichroic substance such as iodine or a dichroic dye, followed by stretching. Examples of resin films used include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially methyl acetalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films. Preferably, from the perspective of superior optical properties, the polarizer is obtained by dyeing the PVA film with iodine and then subjecting it to uniaxial stretching.

[0040] The aforementioned dyeing using iodine is performed, for example, by immersing the PVA membrane in an aqueous iodine solution. The stretching ratio for the uniaxial stretching is preferably 3 to 7 times. Stretching can be performed after dyeing or simultaneously with dyeing. Alternatively, dyeing can be performed after stretching. The PVA membrane can be subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, etc., as needed. For example, by immersing the PVA membrane in water for washing before dyeing, not only can stains and anti-blocking agents on the surface of the PVA membrane be washed away, but the PVA membrane can also swell to prevent uneven dyeing.

[0041] As specific examples of a polarizer obtained using the above-described laminate, polarizers can be obtained using a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. A polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be manufactured, for example, by coating a PVA-based resin solution onto a resin substrate and allowing it to dry 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; the laminate is then stretched and dyed to form a polarizer from the PVA-based resin layer. In this embodiment, it is preferable to form a polyvinyl alcohol-based resin layer comprising a halide and a polyvinyl alcohol-based resin on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and then stretching it. Furthermore, stretching may, as needed, further include air stretching of the laminate at a high temperature (e.g., above 95°C) before stretching in the aqueous boric acid solution. Furthermore, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which it shrinks by more than 2% in the width direction while being conveyed and heated along the length direction. Typically, the manufacturing method of this embodiment includes sequentially performing an air-assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment on the laminate. By introducing assisted stretching, even when PVA is coated on a thermoplastic resin, the crystallinity of PVA can be improved, resulting in high optical properties. Furthermore, by simultaneously improving the orientation of PVA beforehand, problems such as reduced orientation and dissolution of PVA can be prevented when immersed in water during subsequent dyeing and stretching processes, thus achieving high 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 disorder of polyvinyl alcohol molecule orientation and the reduction of orientation can be suppressed. Therefore, the optical properties of the polarizer obtained by immersing the laminate in a liquid through dyeing and underwater stretching treatments can be improved. Furthermore, by using the drying shrinkage treatment to shrink the laminate along the width direction, optical properties can be improved. The resulting resin substrate / polarizer laminate can be used directly (i.e., the resin substrate can be used as a protective layer for the polarizer), or it can be used by laminating any suitable protective layer corresponding to the purpose on the peeled surface after the resin substrate has been peeled from the resin substrate / polarizer laminate, or on the surface opposite to the peeled surface. Detailed descriptions of such a polarizer manufacturing method are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire descriptions of these publications are incorporated herein by reference.

[0042] A-3. Protective Layer The aforementioned protective layer is composed of any suitable film that can be used as a protective layer for a polarizer. Examples of materials constituting the protective layer include cellulose resins such as triacetyl cellulose (TAC), cyclic olefin resins such as polynorbornene, (meth)acrylic resins, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene, and polycarbonate resins. Representative examples of (meth)acrylic resins include those with a lactone ring structure. (Meth)acrylic resins with a lactone ring structure are described, for example, in Japanese Patent Application Publication Nos. 2000-230016, 2001-151814, 2002-120326, 2002-254544, and 2005-146084. These bulletins are cited in this specification for reference.

[0043] The polarizer with phase difference layer is typically disposed on the visible side of the organic EL display device. The visible side protective layer 12 can also be subjected to surface treatments such as hard coating, anti-reflection treatment, anti-sticking treatment, and anti-glare treatment as needed.

[0044] The thickness of the visible side protective layer 12 can be appropriately set. The thickness of the visible side protective layer 12 is preferably 10 μm to 80 μm, more preferably 15 μm to 70 μm, and even more preferably 20 μm to 50 μm. It should be noted that, when surface treatment is performed, the thickness of the visible side protective layer 12 includes the thickness of the surface treatment layer.

[0045] In one embodiment, the ammonia permeation rate of the protective layer 13 is 70 g / m³. 2 • Less than 24 hours, preferably 60g / m 2 • Less than 24 hours, preferably 50g / m 2 • Less than 24 hours, preferably 40g / m 2 • Less than 24 hours, preferably 30g / m 2 • Less than 24 hours. In this case, the material constituting the protective layer 13 is preferably selected from at least one of cellulose resins, cycloolefin resins and polyester resins.

[0046] In one embodiment, the protective layer 13 is preferably optically isotropic. In this specification, "optically isotropic" means that the in-plane phase difference Re(550) is 0 nm to 10 nm, and the phase difference Rth(550) in the thickness direction is -10 nm to +10 nm. The thickness of the protective layer 13 can be appropriately set, for example, according to the desired ammonia permeation. The thickness of the protective layer 13 is preferably 10 μm to 80 μm, more preferably 20 μm to 70 μm, and even more preferably 30 μm to 50 μm. In the case where the phase difference layer 20 is a stretched resin film, the protective layer 13 may be omitted, for example, from the viewpoint of thinning.

[0047] A-4. Phase Difference Layer The phase difference layer 20 can be a single layer or have a stacked structure (essentially a two-layer structure).

[0048] When the phase retardation layer 20 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 the organic EL display device. The refractive index characteristics of the phase retardation layer typically show 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. It should be noted that "ny = nz" here includes not only the case where ny and nz are exactly equal, but also the case where they are substantially equal. Therefore, without impairing the effects of the present invention, it may sometimes be expressed as ny > nz or ny <nz。

[0049] The Nz coefficient of the phase décor 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.

[0050] When the retardation layer is a single layer, it preferably exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases accordingly with the wavelength of the measurement light. In this case, the Re(450) / Re(550) ratio of the retardation layer is preferably 0.8 or higher and lower than 1, more preferably 0.8 or higher and lower than 0.95. With such a configuration, very excellent anti-reflection properties can be achieved.

[0051] The angle between the slow axis of the retardation layer and the absorption axis of the polarizer is preferably 40° to 50°, more preferably 42° to 48°, and even more preferably about 45°. If the angle is within such a range, an organic EL display device with excellent anti-reflective properties can be obtained by fabricating the retardation layer into a λ / 4 plate as described above.

[0052] The retardation layer can be made of any suitable material as long as it meets the above-mentioned characteristics. Specifically, the retardation layer can be a stretched film of a resin film or an alignment-cured layer of a liquid crystal compound (hereinafter, liquid crystal alignment-cured layer).

[0053] In the case of a stretched film in which the phase retardation layer is a resin film, representative examples of the resin constituting the resin film include polycarbonate resins or polyester carbonate resins (hereinafter, sometimes simply referred to as polycarbonate resins). As a polycarbonate resin, any suitable polycarbonate resin can be used as long as the desired moisture permeability can be obtained. For example, a polycarbonate resin may contain structural units derived from fluorene 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, diethylene glycol, triethylene glycol, or polyethylene glycol, and alkylene glycols or spirodiols. Preferred polycarbonate resins include structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, structural units derived from alicyclic diethanol, and / or structural units derived from diethylene glycol, triethylene glycol, or polyethylene glycol; more preferably, they include structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from diethylene glycol, triethylene glycol, or polyethylene glycol. Polycarbonate resins may also include structural units derived from other dihydroxy compounds as needed. The retardation layer can be formed by stretching a film made of the aforementioned polycarbonate resin under any suitable stretching conditions. It should be noted that detailed information regarding the polycarbonate resin and the method for forming the retardation layer is described in, for example, 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.

[0054] When the retardation layer is a liquid crystal alignment-cured layer, by using a liquid crystal compound, the difference between nx and ny of the resulting retardation layer can be significantly increased compared to non-liquid crystal materials, thus significantly reducing the thickness of the retardation layer used to obtain the desired in-plane retardation. As a result, it is possible to further thin the polarizer with the retardation layer (resulting in an organic EL display device). In this specification, "alignment-cured layer" refers to a layer in which a liquid crystal compound is aligned in a predetermined direction and its alignment state is fixed. It should be noted that "alignment-cured layer" includes the concept of an alignment-cured layer obtained by curing liquid crystal monomers. In this embodiment, the rod-shaped liquid crystal compound is typically aligned (parallel alignment) along the slow axis direction of the retardation layer. Specific examples of liquid crystal compounds and details of the method for forming the liquid crystal alignment-cured layer are described, for example, in Japanese Patent Application Publication Nos. 2006-163343 and 2006-178389. These publications are incorporated herein by reference.

[0055] The thickness of the retardation layer can be typically set to a thickness suitable for functioning as a λ / 4 plate. When the retardation layer is a stretched resin film, its thickness can be, for example, 10 μm to 60 μm. When the retardation layer is a liquid crystal alignment and curing layer, its thickness can be, for example, 1 μm to 5 μm.

[0056] When the phase retardation layer 20 has a stacked structure, the phase retardation layer typically has a two-layer structure consisting of a first liquid crystal alignment curing layer and a second liquid crystal alignment curing layer. In this case, either the first liquid crystal alignment curing layer or the second liquid crystal alignment curing layer can function as a λ / 2 plate, and the other can function as a λ / 4 plate. Here, the case where the first liquid crystal alignment curing layer functions as a λ / 2 plate and the second liquid crystal alignment curing layer functions as a λ / 4 plate will be described, but they can also be reversed. The thickness of the first liquid crystal alignment curing layer can be adjusted in a way that yields the desired in-plane phase difference for the λ / 2 plate, for example, it can be 2.0 μm to 4.0 μm. The thickness of the second liquid crystal alignment curing layer can be adjusted in a way that yields the desired in-plane phase difference for the λ / 4 plate, for example, it can be 1.0 μm to 2.5 μm. The in-plane phase difference Re(550) of the first liquid crystal alignment curing layer is preferably 200 nm to 300 nm, more preferably 230 nm to 290 nm, and even more preferably 250 nm to 280 nm. The in-plane phase difference Re(550) of the second liquid crystal alignment curing layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and even more preferably 120 nm to 160 nm, as described above. The angle between the slow axis of the first liquid crystal alignment curing layer and the absorption axis of the polarizer is preferably 10° to 20°, more preferably 12° to 18°, and even more preferably about 15°. The angle between the slow axis of the second liquid crystal alignment curing layer and the absorption axis of the polarizer is preferably 70° to 80°, more preferably 72° to 78°, and even more preferably about 75°. With this configuration, characteristics close to ideal reverse wavelength dispersion can be obtained, resulting in very excellent anti-reflection characteristics.

[0057] In one embodiment, the ammonia permeation rate of the phase retardation layer 20 is 70 g / m². 2 • Less than 24 hours, preferably 60g / m 2 • Less than 24 hours, preferably 50g / m 2 • Less than 24 hours, preferably 40g / m 2 • Less than 24 hours, preferably 30g / m 2 • 24 hours or less. In this case, the stretch film of the above-mentioned resin film is preferably used as the phase retardation layer 20. As the constituent material of the protective layer 13 combined with the stretch film of the resin film, i.e., the phase retardation layer 20, at least one selected from cycloolefin resins and polyester resins is preferably used. According to such a combination, discoloration can be significantly suppressed.

[0058] Cellulose-based resins are preferably used as the constituent material of the protective layer 13, which is combined with the liquid crystal alignment curing layer, i.e., the retardation layer 20. With this combination, discoloration can be significantly suppressed.

[0059] B. Organic EL display device The aforementioned polarizer with a phase retardation layer can be applied to organic EL display devices. Therefore, the organic EL display device according to an embodiment of the present invention has the aforementioned polarizer with a phase retardation layer.

[0060] Figure 2 This is a schematic cross-sectional view showing a state in which a polarizer with a phase retardation layer is disposed on an organic EL panel in an organic EL display device according to one embodiment of the present invention. The polarizer 100 with the phase retardation layer is disposed such that its blocking layer 30 is on the side of the organic EL panel body 40 compared to the polarizer 11. Specifically, the polarizer 100 with the phase retardation layer is attached to the organic EL panel body 40 via an adhesive layer (not shown). The organic EL panel body 40 has a substrate 60 and an upper structural layer 80 including a circuit layer containing thin-film transistors (TFTs), an organic light-emitting diode (OLED), a sealing film sealing the OLED, etc. The upper structural layer 80 includes, for example, a nitrogen-containing layer (e.g., a nitride layer), and ammonia (ammonia ions) can be generated from the upper structural layer 80. According to the above-described polarizer with a phase retardation layer, color fading can be significantly suppressed in the organic EL display device. Furthermore, the problem of color fading can be solved without designing changes to the structure of the organic EL panel body.

[0061] For example, when a flexible substrate (e.g., a resin substrate) is used as substrate 60, the resulting organic EL display device can be bent, flexed, folded, rolled up, etc.

[0062] Example The present invention will now be specifically described through examples, but the present invention is not limited to these examples. The methods for measuring each characteristic are described below. It should be noted that, unless otherwise specified, "parts" and "%" in the examples and comparative examples are based on weight.

[0063] (1) Thickness Thicknesses below 10 μm 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 ANRITSU Co., Ltd., product name "KC-351C").

[0064] (2) Ammonia permeation rate Prepare two cups, A and B. Add 150g of a 10% ammonia solution to cup A and 150g of water to cup B. Seal both cups with a 6cm diameter circular test piece (membrane). Place both cups in an oven set at 40℃ (at atmospheric pressure) for 24 hours. Measure the weight change of cups A and B before and after standing. Calculate the difference between the weight change of cup A (ammonia and water permeation) and the weight change of cup B (water permeation). Determine the ammonia permeation rate (g / m³). 2 •24h).

[0065] [Example 1] 1. Fabrication of the polarizer As the thermoplastic resin substrate, an amorphous polyethylene terephthalate copolymer film (thickness: 100 μm) with a strip shape, a water absorption rate of 0.75%, and a Tg of approximately 75 °C was used. One side of the resin substrate was subjected to corona treatment.

[0066] 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 acetoacetyl modified PVA (manufactured by Japan Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z410") in a ratio of 9:1. The resulting substance was dissolved in water to prepare a PVA aqueous solution (coating solution).

[0067] A PVA-based resin layer with a thickness of 13 μm was formed by coating the corona-treated surface of the resin substrate with the above-mentioned PVA aqueous solution and drying it at 60°C, thus creating a laminate.

[0068] The resulting laminate was subjected to uniaxial stretching at the free end to 2.4 times its original length between rollers with different circumferential speeds in an oven at 130°C (air-assisted stretching treatment).

[0069] Next, the laminate was immersed in an insoluble bath (an aqueous solution of boric acid prepared by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insoluble treatment).

[0070] Next, the polarizing film is immersed in a staining bath at 30°C (an aqueous solution of iodine and potassium iodide prepared by mixing iodine and potassium iodide in a weight ratio of 1:7 relative to 100 parts by weight of water) for 60 seconds (staining treatment), while adjusting the concentration so that the monomer transmittance (Ts) of the final polarizing film is 43.0%.

[0071] Next, immerse the sample in a crosslinking bath at a liquid temperature of 40°C (an aqueous solution of boric acid 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) for 30 seconds (crosslinking treatment).

[0072] Subsequently, the laminate was immersed in a boric acid aqueous solution (boric acid concentration 4.0 wt%, potassium iodide 5.0 wt%) at a liquid temperature of 70°C, while being uniaxially stretched (underwater stretching treatment) along the longitudinal direction (length direction) between rollers with different circumferential speeds, with a total stretching ratio of 5.5.

[0073] The laminate was then immersed in a washing bath at 20°C (an aqueous solution of 4 parts by weight of potassium iodide relative to 100 parts by weight of water) for washing treatment.

[0074] Subsequently, while drying in an oven maintained at 90°C, it is contacted with a SUS heated roller with a surface temperature maintained at 75°C for approximately 2 seconds (drying shrinkage treatment). The width-direction shrinkage rate of the laminate treated with drying shrinkage treatment is 5.2%.

[0075] By operating in this way, a polarizer with a thickness of 5 μm is formed on a resin substrate.

[0076] 2. Fabrication of Polarizing Films On the polarizer surface of the resin substrate / polarizer laminate obtained above, a 25 μm thick TAC film is bonded using a UV-curable adhesive. Specifically, the adhesive is applied with a curable thickness of 1.0 μm and bonded using a roller. Then, UV light is irradiated from the TAC film side to cure the adhesive. Next, the resin substrate is peeled off from the polarizer, and a cyclic olefin resin film (13 μm thick, ammonia permeability 54 g / m²) is bonded to the peeled surface in the same manner as described above. 2 • 24h: below, COP film). By operating in this way, a polarizer with a structure of TAC film / polarizer / COP film is obtained.

[0077] 3. Fabrication of the retardation film constituting the retardation layer 3-1. Polymerization of polyester carbonate resins Polymerization was carried out in a batch polymerization unit consisting of two vertical reactors equipped with agitators and reflux coolers controlled at 100°C. The following components were added: 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluorene-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. -2 Parts by weight (6.78 × 10) -5(mol). After nitrogen purging under reduced pressure in the reactor, it is heated with a heat 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, the pressure is set to 13.3 kPa for 90 minutes. Phenol vapor, a byproduct of the polymerization reaction, is introduced into a 100°C reflux cooler to return some monomer components from the phenol vapor to the reactor. Uncondensed phenol vapor is recovered in a 45°C condenser. Nitrogen is introduced into the first reactor to temporarily restore the pressure to atmospheric pressure, and the oligomerized reaction liquid in the first reactor is transferred to the second reactor. Then, heating and depressurization are initiated in the second reactor, setting the internal temperature to 240°C and the pressure to 0.2 kPa for 50 minutes. Polymerization then continues until the specified stirring power is achieved. Nitrogen is introduced into the reactor at the specified power point and repressurized to extrude the generated polyester carbonate resin into the water, and the strands are cut to obtain granules.

[0078] 3-2. Fabrication of the phase retardation film After vacuum drying the obtained polyester carbonate resin (granules) at 80°C for 5 hours, a strip-shaped resin film with a thickness of 135 μm was produced using a film forming apparatus equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250°C), a T-die (width 200 mm, set temperature: 250°C), a chilled roll (set temperature: 120~130°C), and a winding machine. The obtained strip-shaped resin film was stretched along its width at a stretching temperature of 133°C and a stretching ratio of 2.8 times to obtain a phase retardation film with a thickness of 47 μm. The obtained phase retardation film has a Re(550) of 141 nm, a Re(450) / Re(550) of 0.82, and an Nz coefficient of 1.12. In addition, the ammonia permeation of the obtained phase retardation film is 10 g / m³. 2 ·24h.

[0079] 4. Preparation of adhesives 4-1. Preparation of acrylic polymers A monomer mixture containing 91 parts butyl acrylate, 6 parts acrylamide (ACMO), 2.7 parts acrylic acid, and 0.3 parts 4-hydroxybutyl acrylate was added to a four-necked flask equipped with a stirring blade, thermometer, nitrogen inlet pipe, and cooler. Then, 0.1 parts of 2,2'-azobisisobutyronitrile (2,2'-ANOVA), acting as a polymerization initiator, were added along with 100 parts ethyl acetate to 100 parts of this monomer mixture. Nitrogen was introduced while the mixture was slowly stirred to perform nitrogen purging. The liquid temperature in the flask was maintained at approximately 55°C for 8 hours to carry out the polymerization reaction, thus preparing an acrylic polymer solution.

[0080] 4-2. Preparation of Adhesive To obtain an adhesive, 0.1 parts of trimethylolpropane / toluene diisocyanate adduct (Tosoh Corporation, trade name "Coronate L"), 0.3 parts of peroxide crosslinking agent (benzoyl peroxide), and 0.2 parts of epoxy-containing silane coupling agent (Shin-Etsu Chemical Co., Ltd., trade name "KBM-403") were added to 100 parts of the solids component of the obtained acrylic polymer solution. The ammonia permeation of the obtained adhesive (20 μm thickness) was 118 g / m³. 2 ·24h.

[0081] 5. Fabrication of polarizers with phase retardation layers The COP film surface of the polarizer obtained in step 2 above is bonded to the retardation film obtained in step 3 above using the adhesive (20 μm thick) obtained in step 4 above. At this time, the bonding is performed such that the absorption axis of the polarizer and the slow axis of the retardation film are at a 45° angle. By operating in this manner, a polarizer with a retardation layer is obtained.

[0082] [Example 2] In the fabrication of polarizers, PET film (30μm thickness, ammonia permeability 53g / m²) is used. 2 Instead of the COP film, a polarizer with a phase difference layer was obtained by operating in the same manner as in Example 1.

[0083] [Example 3] In the fabrication of polarizers, a TAC film (25 μm thickness, ammonia permeability 30 g / m²) is used. 2 Instead of the COP film, a polarizer with a phase difference layer was obtained by operating in the same manner as in Example 1.

[0084] [Example 4] In the fabrication of the polarizer, an acrylic film with an lactone ring structure (20 μm thickness, ammonia permeability 78 g / m²) is used. 2 Instead of the COP film, a polarizer with a phase difference layer was obtained by operating in the same manner as in Example 1.

[0085] [Example 5] In the fabrication of the polarizer, the COP film was not bonded to the polarizer using an ultraviolet-curing adhesive. Otherwise, the process was the same as in Example 1 to obtain a polarizer with a phase retardation layer.

[0086] [Example 6] As the phase retardation layer, the liquid crystal alignment curing layer described below is used. Otherwise, the operation is the same as in Example 1 to obtain a polarizer with a phase retardation layer.

[0087] (Fabrication of the liquid crystal alignment and 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 further 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, an alignment film was coated onto a 0.7 mm thick glass substrate using a polyimide solution by spin coating. After drying at 100°C for 10 minutes, the film was calcined at 200°C for 60 minutes to obtain a coating film. The obtained coating film was subjected to a friction treatment to form an alignment film. Friction treatment was performed using a commercially available friction device. The polymeric composition obtained above was coated onto a substrate (essentially an oriented film) by spin coating and dried at 100°C for 2 minutes. After cooling the resulting coated film to room temperature, it was then subjected to a high-pressure mercury lamp at 30 mW / cm². 2 A liquid crystal alignment-cured layer was obtained by irradiating the liquid crystal alignment-cured layer with ultraviolet light at an intensity of 180 ppm for 30 seconds. The in-plane phase difference Re(550) of the obtained liquid crystal alignment-cured layer was 130 nm, and the Re(450) / Re(550) ratio was 0.851, exhibiting inverse dispersion wavelength characteristics. Furthermore, the ammonia permeation rate of the obtained liquid crystal alignment-cured layer was 103 g / m³. 2 ·24h.

[0088] [Chemical Formula 1] [Chemical Formula 2] [Example 7] In the fabrication of polarizers, a TAC film (25 μm thickness, ammonia permeability 30 g / m²) is used. 2 The above-mentioned liquid crystal alignment curing layer is used instead of the COP film (24h); and when it is attached to the polarizer, the above-mentioned adhesive is not used but an ultraviolet curing adhesive (1.0 μm thick). Otherwise, the operation is the same as in Example 1 to obtain a polarizer with a phase retardation layer.

[0089] [Comparative Example 1] In the fabrication of the polarizer, a 40 μm thick TAC film was used instead of a 25 μm thick TAC film, and an acrylic film with a lactone ring structure (20 μm thick, ammonia permeability 78 g / m²) was used. 2The above-mentioned liquid crystal alignment curing layer was used instead of the COP film (24h); and, otherwise, the polarizer with the phase retardation layer was obtained by operating in the same manner as in Example 1.

[0090] [Comparative Example 2] In the fabrication of the polarizer, a 40 μm thick TAC film was used instead of a 25 μm thick TAC film; and, as the phase retardation layer, the above-mentioned liquid crystal alignment curing layer was used. Otherwise, the process was the same as in Example 5 to obtain a polarizer with a phase retardation layer.

[0091] [Comparative Example 3] In the fabrication of the polarizer, an acrylic film (20 μm thick) with a lactone ring structure is used instead of a 25 μm thick TAC film. The acrylic film with a lactone ring structure (20 μm thick, ammonia permeability 78 g / m²) is used. 2 The above-mentioned liquid crystal alignment curing layer was used instead of the COP film (24h); and, otherwise, the polarizer with the phase retardation layer was obtained by operating in the same manner as in Example 1.

[0092] The following evaluations were conducted for the embodiments and comparative examples. The evaluation results, along with the configuration of the polarizer (blocking layer) with the phase retardation layer, are summarized in Table 1.

[0093] <Evaluation> Monomer transmittance and polarization For the polarizers in the examples and comparative examples, the single-cell transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc, measured using a UV-Vis spectrophotometer (Otsuka Electronics Co., Ltd. "LPF-2000"), were set as the polarizer's Ts, Tp, and Tc, respectively. These Ts, Tp, and Tc were Y values ​​measured using a 2-degree field of view (C light source) of a JIS Z8701 and corrected for visibility. The polarization P was calculated from the obtained Tp and Tc using the following formula.

[0094] Polarization P (%) = {(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100 Ammonia decolorization test 10g of a 10% ammonia solution was added to a glass bottle (cylindrical, 30mm in diameter and 50mm in depth). The opening of the glass bottle was sealed by covering it with a polarizer with a phase retardation layer (the phase retardation layer was in contact with the opening) as obtained in the examples and comparative examples. The glass bottle was then heated at 65°C for 2 hours. After heating, the polarization of the portion corresponding to the opening of the glass bottle was measured. The polarization of the polarizer with a phase retardation layer (essentially a polarizer) before heating was set as P, and the polarization after heating was set as P'. ΔP was calculated using the following formula. The smaller ΔP is, the more suppressed the decolorization caused by ammonia is.

[0095] ΔP=P-P' In the embodiments, polarizers with phase retardation layers were obtained with ΔP below 20% and whose polarization remained essentially unchanged (no decolorization) even when exposed to ammonia. On the other hand, it was also confirmed that in the comparative examples, the polarization was significantly reduced, and the polarization function was essentially lost.

[0096] Industrial availability The polarizer with a phase difference layer of the present invention is suitable, for example, as an anti-reflective circular polarizer for organic EL display devices.

[0097] Explanation of symbols 10 Polarizing filters 11. Polarizer 12. Protective layer (visible side protective layer) 13. Protective layer (inner protective layer) 20 phase difference layers 30 barrier layers 100 Polarizers with Phase Difference Layers

Claims

1. A polarizer with a phase retardation layer, comprising: polarizer; and A blocking layer disposed on one side of the polarizer and comprising a protective layer and a phase difference layer of the polarizer; The protective layer is composed of at least one selected from cyclic olefin resins and polyester resins. The ammonia permeation rate of the barrier layer is 70 g / m³. 2 • Less than 24 hours.

2. The polarizer with a phase retardation layer according to claim 1, wherein, The ammonia permeation rate of the phase difference layer is 70 g / m³. 2 • Less than 24 hours.

3. The polarizer with a phase retardation layer according to claim 1, wherein, The ammonia permeation rate of the protective layer is 70 g / m³. 2 • Less than 24 hours.

4. The polarizer with a phase difference layer according to any one of claims 1 to 3, wherein it has a protective layer disposed on the other side of the polarizer.

5. The polarizer with a phase retardation layer according to any one of claims 1 to 3, wherein, The polarizer has a single-unit transmittance of 40% or more and 45% or less.

6. The polarizer with a phase retardation layer according to any one of claims 1 to 3, wherein, The Re(450) / Re(550) ratio of the phase difference layer is greater than 0.8 and less than 1.

7. The polarizer with a phase retardation layer according to any one of claims 1 to 3, wherein, The thickness of the polarizer is less than 10 μm.

8. The polarizer with a phase difference layer according to any one of claims 1 to 3, wherein the thickness is 150 μm or less.

9. An organic electroluminescent display device comprising a polarizer with a phase retardation layer as described in any one of claims 1 to 8.

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