Organic electroluminescent display device

Abstract

The problem addressed by the present invention is to provide an organic electroluminescent display device in which changes in oblique colors (white) at various angles of orientation are reduced. This organic electroluminescent display device includes a circular polarizing plate and an organic electroluminescent display element. The circular polarizing plate includes an optically anisotropic layer and a polarizer, in that order from the organic electroluminescent display element side. At each of angles of orientation produced by rotation in 45° increments with a direction parallel to a transmission axis of the polarizer as a baseline, determined is the ratio of luminescence of p-polarized light to luminescence of s-polarized light when the organic electroluminescent display element displays white at a polar angle of 60° relative to the direction of a normal line to the organic electroluminescent display element. x and y satisfy a prescribed relationship if x is the arithmetic average value of the ratio of luminescence of p-polarized light to luminescence of s-polarized light at all of the angles of orientation and y is the ratio of in-plane retardation at a wavelength of 600 nm to in-plane retardation at a wavelength of 440 nm in the optically anisotropic layer.

Description

Organic electroluminescent display device

[0001] The present invention relates to an organic electroluminescent display device.

[0002] Conventionally, a circular polarizer has been used in an organic electroluminescence display device (hereinafter also referred to as an "organic EL display device") to suppress adverse effects caused by external light reflection. Patent Document 1 discloses an organic EL display device including a circular polarizer and an organic electroluminescence display element (hereinafter also referred to as an "organic EL display element").

[0003] International Publication No. 2019 / 022156

[0004] Recently, there has been a demand for organic EL display devices that exhibit less change in oblique color (white) at each azimuth angle. The present inventors have studied organic EL display devices obtained by combining a circular polarizer and an organic EL display element with reference to Patent Document 1, and have found that the above-mentioned effect may not be obtained depending on the combination of the circular polarizer and the organic EL display element.

[0005] In view of the above circumstances, an object of the present invention is to provide an organic EL display device in which the change in oblique color (white) at each azimuth angle is reduced.

[0006] The present inventors have conducted extensive research to solve the above problems and have completed the present invention having the following configuration.

[0007] (1) An organic electroluminescent display device comprising a circular polarizer and an organic electroluminescent display element, wherein the circular polarizer comprises, from the organic electroluminescent display element side, an optically anisotropic layer and a polarizer, and wherein the ratio of the luminance of P-polarized light to the luminance of S-polarized light when the organic electroluminescent display element displays white light in a direction where the polar angle with respect to the normal direction of the organic electroluminescent display element is 60° is calculated at each azimuth angle rotated by 45° from a direction parallel to the transmission axis of the polarizer, and the arithmetic mean value of the ratio of the luminance of P-polarized light to the luminance of S-polarized light at each azimuth angle is defined as x, and the ratio of the in-plane retardation at a wavelength of 600 nm to the in-plane retardation at a wavelength of 440 nm of the optically anisotropic layer is defined as y, the organic electroluminescent display device satisfies requirements 1 and 2. Requirement 1: y≦−0.155x+1.655 Requirement 2: y≧0.170x+0.980 The ratio of the luminance of P-polarized light to the luminance of S-polarized light is the arithmetic mean value of the ratios of the luminance of P-polarized light to the luminance of S-polarized light at each wavelength increment of 10 nm in the wavelength range of 420 to 680 nm. (2) The organic electroluminescent display device according to (1), which satisfies requirements 3 and 4. Requirement 3: y≦−0.240x+1.740 Requirement 4: y≧0.260x+0.890 (3) The organic electroluminescent display device according to (1) or (2), in which the optically anisotropic layer is a λ / 4 plate.

[0008] According to the present invention, it is possible to provide an organic EL display device in which the change in oblique color (white) at each azimuth angle is small.

[0009] Fig. 2 is a cross-sectional view of one embodiment of the organic EL display device of the present invention. Fig. 2 is a diagram showing the relationship between the absorption axis of a polarizer and the in-plane slow axis of an optically anisotropic layer in the organic EL display device shown in Fig. 1. Fig. 3 is a diagram for explaining a state in which light is incident on the optically anisotropic layer and the polarizer. Fig. 4 is a diagram showing the relationship between the absorption axis of a polarizer and the in-plane slow axis of the optically anisotropic layer in the organic EL display device shown in Fig. 1. Fig. 5 is a diagram for explaining a state in which light is incident on the optically anisotropic layer and the polarizer. Fig. 6 is a diagram for explaining requirement 1 and requirement 2.

[0010] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0011] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In this specification, "visible light" means light having a wavelength in the range of 380 to 780 nm. Unless otherwise specified, the measurement wavelength is 550 nm. In this specification, the "in-plane slow axis" means the direction in which the refractive index is maximum in the plane.

[0012] In this specification, Re(λ) and Rth(λ) represent the in-plane retardation and the thickness direction retardation, respectively, at a wavelength λ. Unless otherwise specified, the wavelength λ is 550 nm. Re(λ) and Rth(λ) are values ​​measured at a wavelength λ using an AxoScan manufactured by Axometrics. By inputting the average refractive index ((nx + ny + nz) / 3) and film thickness (d (μm)) into AxoScan, the following slow axis direction (°) is calculated: Re(λ) = R0(λ) Rth(λ) = ((nx + ny) / 2 - nz) × d Note that R0(λ) is displayed as a numerical value calculated by AxoScan, but it means Re(λ).

[0013] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) with a sodium lamp (λ=589 nm) as a light source. When measuring wavelength dependency, measurements can be made using a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) in combination with an interference filter. Values ​​from the Polymer Handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can also be used. Examples of average refractive index values ​​for major optical films are listed below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0014] In this specification, the term "light" refers to actinic rays or radiation, such as the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays (EUV light), X-rays, ultraviolet rays, and electron beams (EB). Of these, ultraviolet rays are preferred.

[0015] In this specification, A plates and C plates are defined as follows. There are two types of A plates: positive A plates (positive A plates) and negative A plates (negative A plates). When the refractive index in the in-plane slow axis direction (the direction in which the in-plane refractive index is maximum) of the film is nx, the refractive index in the in-plane direction perpendicular to the in-plane slow axis is ny, and the refractive index in the thickness direction is nz, the positive A plates satisfy the relationship of formula (A1), and the negative A plates satisfy the relationship of formula (A2). Note that the positive A plates have a positive Rth value, and the negative A plates have a negative Rth value. Formula (A1) nx>ny≒nz Formula (A2) ny<nx≒nz Note that the above "≒" includes not only the case where the two are completely identical, but also the case where the two are substantially identical. "Substantially the same" means, for example, that "ny ≒ nz" also includes cases where (ny - nz) x d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, and "nx ≒ nz" also includes cases where (nx - nz) x d is -10 to 10 nm, preferably -5 to 5 nm. There are two types of C plates: positive C plates (positive C plates) and negative C plates (negative C plates). Positive C plates satisfy the relationship of formula (C1), while negative C plates satisfy the relationship of formula (C2). Note that positive C plates have a negative Rth value, and negative C plates have a positive Rth value. Formula (C1) nz > nx ≒ ny Formula (C2) nz < nx ≒ ny Note that the above "≒" includes not only cases where the two are completely identical, but also cases where the two are substantially identical. The term "substantially the same" includes, for example, the case where (nx-ny) x d (where d is the thickness of the film) is 0 to 10 nm, preferably 0 to 5 nm, in "nx≈ny".

[0016] In this specification, the terms "perpendicular" and "parallel" include the range of tolerance allowed in the technical field to which the present invention pertains. For example, they mean a tolerance of ±5° from the exact angle, and the tolerance from the exact angle is preferably ±3°.

[0017] In this specification, the "fixed" state refers to a state in which the alignment of the liquid crystal compound is maintained. Specifically, it is preferable that the layer has no fluidity and the alignment state is not changed by an external field or external force, usually in a temperature range of 0 to 50°C, or under more severe conditions, in a temperature range of -30 to 70°C, and that the fixed alignment state can be stably maintained.

[0018] [Organic EL Display Device] An embodiment of the organic EL display device of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross-sectional view of an embodiment of the organic EL display device of the present invention. Note that the drawings in this invention are schematic diagrams, and the thickness and positional relationships of the various layers do not necessarily correspond to the actual ones. The same applies to the following drawings. The organic EL display device 10 includes, from the viewer's side (the upper side in the drawing), a circular polarizer 20 and an organic EL display element 30. The circular polarizer 20 includes, from the viewer's side, a polarizer 22 and an optically anisotropic layer 24. The organic EL display element 30 includes a polarization adjustment layer 32 and an organic EL substrate 34. In the embodiment shown in FIG. 1, the organic EL display element 30 includes the polarization adjustment layer 32 and the organic EL substrate 34, but is not limited to this embodiment.

[0019] A feature of the present invention is that the ratio of the luminance of P-polarized light to the luminance of S-polarized light (hereinafter also referred to as "P / S") when the organic EL display element displays white light in a direction where the polar angle with respect to the normal direction of the organic EL display element is 60° is calculated at each azimuth angle rotated by 45° from the direction parallel to the transmission axis of the polarizer, and the arithmetic mean value x (hereinafter also referred to as "x value") of the ratio of the luminance of P-polarized light to the luminance of S-polarized light at each azimuth angle and y (hereinafter also referred to as "y value") of the ratio of the in-plane retardation of the optically anisotropic layer at a wavelength of 600 nm to the in-plane retardation at a wavelength of 440 nm satisfy the requirements 1 and 2 described below. In an organic EL display device including a circular polarizer and an organic EL display element, light is emitted from the organic EL display element side and transmitted through the circular polarizer, and the light includes P-polarized and S-polarized light. The amount of P-polarized and S-polarized light transmitted through the circular polarizer may vary significantly depending on the wavelength and azimuth angle, which is presumably why the oblique color (white) varies significantly at each azimuth angle. More specifically, this will be explained using Figures 2 and 3. Figure 2 shows the relationship between the absorption axis of the polarizer 22 and the in-plane slow axis of the optically anisotropic layer 24 in the organic EL display device 10 shown in Figure 1. In Figure 2, the absorption axis of the polarizer 22 is parallel to the y-axis direction, and the angle between the in-plane slow axis of the optically anisotropic layer 24 and the y-axis direction is 45°. Figure 3 shows a mode in which light is incident obliquely from the side of the optically anisotropic layer 24 opposite the polarizer 22 side. In FIG. 3 , light is divided into P-polarized light and S-polarized light, and their vibration directions are indicated by the black and white arrows in FIG. 2 . When such P-polarized light and S-polarized light are incident on the optically anisotropic layer 24 obliquely along the x-axis, their polarization states change. Depending on the value of y, which is the ratio of the in-plane retardation of the optically anisotropic layer 24 at a wavelength of 600 nm to the in-plane retardation at a wavelength of 440 nm, the incident P-polarized light and S-polarized light may be polarized in different absorption rates relative to the absorption axis of the polarizer 22. In the embodiment shown in FIG. 3 , the P-polarized light is polarized in a state where it is less easily absorbed by the polarizer 22. By rotating the organic EL display device 10 by 45°, the relationship between the absorption axis of the polarizer 22 and the in-plane slow axis of the optically anisotropic layer 24 is as shown in FIG. 4 .Next, as shown in FIG. 5 , light is obliquely incident on the optically anisotropic layer 24 from the side opposite the polarizer 22, as in FIG. 3 . In FIG. 5 , the light is divided into P-polarized and S-polarized light, and their vibration directions are indicated by the black and white arrows in FIG. 4 . When such P-polarized and S-polarized light enter the optically anisotropic layer 24 obliquely along the x-axis, the polarization state does not change in relation to the in-plane slow axis of the optically anisotropic layer 24, and the P-polarized and S-polarized light are absorbed by the polarizer 22 at approximately the same reduction rate. Typically, when P-polarized and S-polarized light enter various components obliquely, as shown in FIGS. 3 and 5 , S-polarized light is more likely to be reflected at the interface, resulting in a greater concentration of P-polarized light in the transmitted light. As a result, the absorption of P-polarized light is suppressed in the embodiment shown in FIG. 3 compared to the embodiment shown in FIG. 5 . As a result, the brightness of the light transmitted through the polarizer 22 is greater in the embodiment shown in FIG. 3 . Therefore, the color appears different depending on the azimuth angle at which the organic EL display device 10 is viewed. As described above, it has been found that the values ​​of x and y, which will be described later, can cause differences in brightness depending on the azimuth angle. In contrast, in the present invention, if requirements 1 and 2 are satisfied, the amount of change in the amount of P-polarized and S-polarized light transmitted through the circular polarizer due to wavelength and azimuth angle can be suppressed, which is thought to result in less change in oblique color (white) at each azimuth angle. Furthermore, since the organic EL display device 10 includes the circular polarizer 20, it also has excellent ambient light reflectivity. Each component of the organic EL display device 10 will be described in detail below.

[0020] <Circular Polarizer> The organic EL display device 10 includes a circular polarizer 20. The circular polarizer 20 includes, from the organic EL display element 30 side, an optically anisotropic layer 24 and a polarizer 22.

[0021] (Polarizer) The polarizer 22 may be any component capable of converting natural light into specific linearly polarized light, such as an absorptive polarizer. Examples of the polarizer 22 include iodine-based polarizers, dye-based polarizers using dichroic materials, and polyene-based polarizers. Iodine-based polarizers and dye-based polarizers are produced by, for example, adsorbing iodine or a dichroic dye into polyvinyl alcohol and then stretching the resulting material. A protective film may be disposed on one or both sides of the polarizer 22.

[0022] The thickness of the polarizer 22 is not particularly limited, but is preferably 35 μm or less, and more preferably 1 to 25 μm, in terms of ease of handling and excellent optical properties. The above thickness allows for reduction in the thickness of organic EL display devices.

[0023] (Optically Anisotropic Layer) The optically anisotropic layer 24 is preferably a λ / 4 plate. In the embodiment shown in FIG. 1, the optically anisotropic layer 24 is preferably a λ / 4 plate having a single-layer structure, but the embodiment is not limited thereto as long as it is an optically anisotropic layer capable of constituting a circular polarizer. For example, the optically anisotropic layer may be a broadband λ / 4 plate that is a laminate of a λ / 2 plate and a λ / 4 plate. A λ / 4 plate has the function of converting linearly polarized light of a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light), and has an Re(λ) of λ / 4. The optically anisotropic layer 24 is preferably a positive A plate. The angle between the in-plane slow axis of the optically anisotropic layer 24 and the absorption axis of the polarizer 22 is preferably 35 to 55°, more preferably 40 to 50°, and even more preferably 45°. The Re(550) of the optically anisotropic layer 24 is not particularly limited, but is preferably 110 to 160 nm, and more preferably 110 to 150 nm. The optically anisotropic layer 24 may have either normal wavelength dispersion or reverse wavelength dispersion. Of these, reverse wavelength dispersion is preferred. The reverse wavelength dispersion is preferably exhibited in the visible light region.

[0024] The thickness of the optically anisotropic layer 24 is preferably 1 to 10 μm, and more preferably 1 to 5 μm. The thickness of the optically anisotropic layer 24 refers to the average thickness of the optically anisotropic layer 24. The average thickness is determined by measuring the thickness at any five or more points on the optically anisotropic layer 24 and taking the arithmetic average. Hereinafter, when a specific value for the layer thickness is indicated, it refers to the arithmetic average of the thickness measured at any five or more points on a layer, as described above.

[0025] An example of a method for producing the optically anisotropic layer 24 is a method by horizontally aligning a rod-shaped polymerizable liquid crystal compound. Examples include the methods for producing positive A plates described in JP-A-2008-225281 and JP-A-2008-026730. An example of a method for producing an optically anisotropic layer with reverse wavelength dispersion is a method by horizontally aligning a liquid crystal compound with reverse wavelength dispersion. Here, in this specification, a "reverse wavelength dispersion" liquid crystal compound refers to a compound in which, when the in-plane retardation (Re) value of an optically anisotropic layer produced using this compound is measured in the visible light range, the Re value remains constant or increases as the measured wavelength increases. Examples of the liquid crystal compound having reverse wavelength dispersion include compounds represented by general formula (I) described in JP-A-2008-297210 (particularly, the compounds described in paragraphs

[0034] to

[0039] ), compounds represented by general formula (1) described in JP-A-2010-084032 (particularly, the compounds described in paragraphs

[0067] to

[0073] ), and compounds represented by general formula (1) described in JP-A-2016-081035 (particularly, the compounds described in paragraphs

[0043] to

[0055] ).

[0026] <Organic EL Display Element> The organic EL display element 30 is a display element having a pair of electrodes and an organic light-emitting layer sandwiched between them. In addition to the organic light-emitting layer, layers such as a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and a protective layer may be provided between the electrodes of the organic EL display element 30, and each of these layers may have other functions. Various materials can be used to form each layer. The organic EL display element 30 includes a polarization adjustment layer 32 and an organic EL substrate 34.

[0027] (Polarization Adjustment Layer) The polarization adjustment layer 32 adjusts the amount of P-polarized and S-polarized light transmitted through the polarization adjustment layer 32, primarily allowing the amount of P-polarized light to be greater than the amount of S-polarized light. The polarization adjustment layer 32 preferably includes alternating layers in which high-refractive index layers and low-refractive index layers are alternately stacked in this order, and a depolarization layer, with the depolarization layer preferably disposed on the organic EL substrate 34 side. Light emitted from the organic EL substrate 34 (particularly light emitted obliquely) first undergoes depolarization as it passes through the depolarization layer, resulting in light with an equal ratio of P-polarized and S-polarized light. When light transmitted through the depolarization layer (particularly light emitted obliquely) passes through the alternating layers, the difference in the reflection characteristics of P-polarized and S-polarized light at the interfaces between the high-refractive index layers and the low-refractive index layers allows the ratio of P-polarized and S-polarized light in the light transmitted through the alternating layers to be controlled by controlling the number of interfaces. The provision of the polarization adjustment layer 32 with the above-described function facilitates adjustment to the desired x value, described below.

[0028] The alternating layer is a layer in which high-refractive index layers and low-refractive index layers are alternately stacked. Specifically, it is a layer consisting of a high-refractive index layer, a low-refractive index layer, a high-refractive index layer, and a low-refractive index layer, etc., in this order. The high-refractive index layers and the low-refractive index layers are preferably arranged in contact with each other. In other words, it is preferable that there are no other layers between the high-refractive index layers and the low-refractive index layers. In terms of oblique color, the number of high-refractive index layers in the alternating layer is preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, and particularly preferably 1 or 2. In addition, in the alternating layer, the number of high-refractive index layers is preferably one more than the number of low-refractive index layers. For example, when a high-refractive index layer, a low-refractive index layer, and a high-refractive index layer are stacked in this order, the number of high-refractive index layers is one more than the number of low-refractive index layers. In other words, it is preferable that both one surface side and the other surface side of the alternating layer are high-refractive index layers.

[0029] The refractive index of the high refractive index layer at a wavelength of 550 nm is preferably 1.7 to 2.7, more preferably 1.9 to 2.3. There are no particular limitations on the material constituting the high refractive index layer, and known materials can be used. The high refractive index layer may be an inorganic film or an organic film, preferably an inorganic film. When the high refractive index layer is an inorganic film, silicon nitride is preferred as the material constituting the inorganic film. The high refractive index layer is preferably a layer containing silicon nitride (hereinafter also referred to as a "silicon nitride layer"). The silicon nitride layer preferably contains silicon atoms and nitrogen atoms, and may also contain oxygen atoms or hydrogen atoms. Furthermore, the composition ratio of nitrogen atoms to silicon atoms in the silicon nitride layer (element ratio: nitrogen atoms / silicon atoms) is preferably 1.0 to 2.0, more preferably 1.2 to 1.4. The silicon nitride layer may contain other inorganic substances in addition to silicon nitride. The content of silicon nitride is preferably 90 to 100 mass% and more preferably 99 to 100 mass% relative to the total mass of the silicon nitride layer.

[0030] The thickness of the silicon nitride layer is preferably 10 nm or more, more preferably 20 nm or more. The upper limit is preferably 150 nm or less, more preferably 80 nm or less. Note that the thickness of the silicon nitride layer is the thickness of a single film, not the total thickness of multiple silicon nitride layers.

[0031] Examples of methods for forming a silicon nitride layer include sputtering, vacuum deposition, ion plating, and plasma CVD (Chemical Vapor Deposition), and specific examples include the silicon nitride layer forming methods described in JP 2011-063851 A, Japanese Patent No. 3400324, JP 2002-322561 A, and JP 2002-361774 A.

[0032] The low refractive index layer has a lower refractive index than the high refractive index layer. The refractive index of the low refractive index layer at a wavelength of 550 nm is preferably 1.4 to 1.6, more preferably 1.45 to 1.55. The material constituting the low refractive index layer is not particularly limited, and known materials can be used. The low refractive index layer may be an inorganic film or an organic film, and an organic film is preferred. The organic layer preferably contains a known resin. Examples of resins include epoxy resins, acrylic resins, methacrylic resins, polyesters, methacrylic acid-maleic acid copolymers, polystyrene, transparent fluororesins, polyimides, fluorinated polyimides, polyamides, polyamideimides, polyetherimides, cellulose acylates, polyurethanes, polyether ketones, polycarbonates, fluorene ring-modified polycarbonates, alicyclic-modified polycarbonates, and fluorene ring-modified polyesters, with acrylic resins or methacrylic resins being preferred.

[0033] The thickness of the organic layer is preferably 0.3 to 10 μm. Note that the thickness of the organic layer is the thickness of a single film, not the total thickness of a plurality of organic layers.

[0034] Examples of methods for forming the organic layer include a method in which a coating liquid containing a monomer, a polymerization initiator, etc. is applied onto a substrate by a known coating method such as roll coating, gravure coating, or spray coating, dried, and, if necessary, cured by heating, ultraviolet irradiation, electron beam irradiation, etc. Other examples include a flash evaporation method in which the coating liquid is evaporated, the vapor is attached to the substrate, and cooled / condensed to form a liquid film, which is then cured by ultraviolet light or an electron beam, and a transfer method in which a sheet-like organic layer is transferred.

[0035] The alternate layer is preferably a layer in which silicon nitride layers and organic layers are alternately laminated in this order.

[0036] The depolarizing layer is not particularly limited as long as it can depolarize light incident on the depolarizing layer, and examples thereof include known high birefringence resin layers and known diffusion layers. Examples of high birefringence resin layers include layers containing high birefringence resins such as polyethylene terephthalate, acrylic resin, methacrylic resin, and polycarbonate. Examples of diffusion layers include diffusion layers composed of a diffusing agent such as a filler and a resin, and diffusion layers containing a layer containing the diffusing agent and a resin layer. Examples of fillers include inorganic fillers such as silicon dioxide and organic fillers such as acrylic resin.

[0037] The organic EL substrate 34 may be, for example, a substrate that constitutes a known organic EL element, such as the above-mentioned substrate having a pair of electrodes and an organic light-emitting layer sandwiched between them.

[0038] (Other Layers) The organic EL display device may have layers other than the above-mentioned members. Examples of the other layers include adhesion layers. The organic EL display device preferably has adhesion layers between the respective members. Examples of the adhesion layers include known alignment films, known pressure-sensitive adhesive layers, and known adhesive layers.

[0039] Examples of methods for forming an alignment film include rubbing an organic compound (preferably a resin), oblique vapor deposition of an inorganic compound, forming a layer having microgrooves, and forming an organic compound (e.g., ω-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearate) by the Langmuir-Blodgett method (LB film) to accumulate the organic compound. Alternatively, the alignment film may be one that exhibits alignment function upon application of an electric field, a magnetic field, or light irradiation (preferably polarized light). The alignment film is preferably formed by rubbing a polymer. Examples of alignment films include photo-alignment films. The thickness of the alignment film is not particularly limited as long as it can exhibit alignment function, but is preferably 0.01 to 5.0 μm, more preferably 0.05 to 2.0 μm, and even more preferably 0.1 to 0.5 μm. The alignment film may be peelable from the optically anisotropic layer described below.

[0040] <Requirements 1 and 2> It is preferable that the organic EL display device satisfies requirements 1 and 2, and also satisfies requirements 3 and 4. Requirement 1: y≦−0.155x+1.655 Requirement 2: y≧0.170x+0.980 Requirement 3: y≦−0.240x+1.740 Requirement 4: y≧0.260x+0.890 As shown in the graph of FIG. 6 , the desired effect is achieved within the area surrounded by the dashed line indicated as requirement 1 and the dashed line indicated as requirement 2.

[0041] (x Value) The x value is the arithmetic mean value of P / S at each azimuth angle, which is obtained by determining P / S when the organic EL display element displays white light in a direction where the polar angle with respect to the normal direction of the organic EL display element is 60° at each azimuth angle rotated by 45° from the direction parallel to the transmission axis of the polarizer in the organic EL display device. The x value is preferably 1.00 to 2.00, more preferably 1.00 to 1.70, and even more preferably 1.00 to 1.40.

[0042] The method for measuring the x value will be described in detail below. First, azimuth angles are determined by rotating the direction parallel to the transmission axis of the polarizer in the organic EL display device by 45° increments. Examples of azimuth angles include 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°, where 0° is the direction parallel to the transmission axis of the polarizer. Next, at any of the above azimuth angles, the P / S ratio when the organic EL display element displays white light is determined in a direction where the polar angle relative to the normal direction of the organic EL display element is 60° from the viewing side of the organic EL display device. P / S values ​​are also measured in the same way for other azimuth angles, and the arithmetic mean value of the obtained P / S values ​​is then used as the x value. Note that P / S is the arithmetic mean value of the ratio of the luminance of P-polarized light to the luminance of S-polarized light at wavelengths in 10-nm increments in the wavelength range of 420 to 680 nm. The luminance of P-polarized light and S-polarized light can be measured using, for example, an SR-UL1 spectroradiometer.

[0043] The x value can be adjusted, for example, by adjusting the configuration of the polarization adjustment layer (for example, the number of silicon nitride layers and organic layers stacked, and the refractive index of each layer).

[0044] (y Value) The y value is the ratio of Re(600) to Re(440) of the optically anisotropic layer (Re(600) / Re(440)). The y value is a preferred embodiment of the above-mentioned x value, and is preferably a value that satisfies requirements 1 and 2, and more preferably a value that satisfies requirements 3 and 4. The y value is preferably 1.15 to 1.50, more preferably 1.23 to 1.45, and even more preferably 1.30 to 1.40.

[0045] Re(600) is not particularly limited, but is preferably 125 to 175 nm, more preferably 135 to 165 nm. Re(440) is not particularly limited, but is preferably 85 to 135 nm, more preferably 95 to 125 nm. The optically anisotropic layer may have either normal wavelength dispersion or reverse wavelength dispersion. Of these, reverse wavelength dispersion is preferred. The reverse wavelength dispersion is preferably exhibited in the visible light region.

[0046] 1 described above, an embodiment including an optically anisotropic layer that is preferably a λ / 4 plate has been described, but the organic EL display device of the present invention may also include other optically anisotropic layers. Examples of other optically anisotropic layers include an optically anisotropic layer having a retardation in the thickness direction (preferably a positive C plate). The optically anisotropic layer having a retardation in the thickness direction as described above is preferably disposed between the polarizer and the organic EL display element, and more preferably disposed between the optically anisotropic layer that is a λ / 4 plate included in the circular polarizer and the organic EL display element.

[0047] The Rth(550) of the optically anisotropic layer having a retardation in the thickness direction is not particularly limited, but is preferably −120 to −20 nm, more preferably −100 to −40 nm. The optically anisotropic layer having a retardation in the thickness direction may exhibit either forward wavelength dispersion or reverse wavelength dispersion. The forward wavelength dispersion and reverse wavelength dispersion are preferably exhibited in the visible light region.

[0048] The thickness of the optically anisotropic layer having a retardation in the thickness direction is not particularly limited, but is preferably 10 μm or less, more preferably 0.1 to 5.0 μm, and even more preferably 0.3 to 2.0 μm.

[0049] Examples of methods for producing an optically anisotropic layer having a retardation in the thickness direction include methods for vertically aligning a rod-shaped polymerizable liquid crystal compound, such as the methods for producing a positive C plate described in JP-A-2017-187732, JP-A-2016-53709, and JP-A-2015-200861.

[0050] The white display of an organic EL display element means that the color range in the CIE 1931 color system, in the direction normal to the organic EL display element from the viewing side of the organic EL display device, is within the range of 0.293 to 0.333 for CIE x and 0.309 to 0.349 for CIE y.

[0051] [Method for manufacturing organic EL display device] The organic EL display device is not particularly limited, and a known method can be used. For example, a method can be mentioned in which an optically anisotropic layer-forming composition containing a predetermined polymerizable liquid crystal compound is applied to a predetermined substrate to form a coating film, the coating film is subjected to an alignment treatment, and then a curing treatment is performed to form a predetermined optically anisotropic layer, the formed optically anisotropic layer and a polarizer are laminated via an adhesive layer to prepare a circular polarizing plate, and the produced circular polarizing plate is then attached to an organic EL display element.

[0052] When the optically anisotropic layer-forming composition is used, the liquid crystal compound having a polymerizable group (hereinafter also referred to as "polymerizable liquid crystal compound") contained in the optically anisotropic layer-forming composition is appropriately selected to be optimal for the formation of each optically anisotropic layer. The content of the polymerizable liquid crystal compound in the optically anisotropic layer-forming composition is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, based on the total solid content of the optically anisotropic layer-forming composition. Note that the solid content refers to components capable of forming an optically anisotropic layer from which the solvent has been removed, and is considered to be solid content even if the components are in a liquid state.

[0053] The composition for forming an optically anisotropic layer may contain other components in addition to the polymerizable liquid crystal compound, such as a chiral agent, a polymerization initiator, a polyfunctional monomer, an alignment control agent (a vertical alignment agent and a horizontal alignment agent), a surfactant, an adhesion improver, a plasticizer, a solvent, and a photoalignable polymer.

[0054] The chiral agent is not particularly limited as long as it is compatible with the liquid crystal compound used in combination. Examples of the chiral agent include known chiral agents (for example, those described in "Liquid Crystal Device Handbook," edited by the 142nd Committee of the Japan Society for the Promotion of Science, Chapter 3, Section 4-3, "Chiral Agents for TN and STN," p. 199, 1989).

[0055] The polymerization initiator is selected depending on the type of polymerization reaction, and examples thereof include a thermal polymerization initiator and a photopolymerization initiator. The content of the polymerization initiator in the composition for forming an optically anisotropic layer is preferably 0.01 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total solid content of the composition for forming an optically anisotropic layer.

[0056] Examples of methods for applying the composition for forming an optically anisotropic layer include curtain coating, dip coating, spin coating, print coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, and wire bar coating.

[0057] The alignment treatment can be carried out by drying the coating film at room temperature or by heating the coating film. In the case of a thermotropic liquid crystal compound, the liquid crystal phase formed by the alignment treatment can generally be transitioned by a change in temperature or pressure. In the case of a lyotropic liquid crystal compound, the transition can also be achieved by adjusting the composition ratio, such as the amount of solvent. The conditions for heating the coating film are not particularly limited, but the heating temperature is preferably 50 to 250°C, more preferably 50 to 150°C, and the heating time is preferably 10 seconds to 10 minutes. After heating the coating film, the coating film may be cooled, if necessary, before the curing treatment (light irradiation treatment) described below.

[0058] The method of curing the coating film in which the polymerizable liquid crystal compound is oriented is not particularly limited, and examples thereof include light irradiation and heat treatment. Among these, from the viewpoint of manufacturability, light irradiation is preferred, and ultraviolet irradiation is more preferred. The irradiation conditions for the light irradiation are not particularly limited, but are preferably 50 to 1000 mJ / cm. ２The atmosphere during the light irradiation treatment is not particularly limited, but a nitrogen atmosphere is preferred.

[0059] When forming another optically anisotropic layer directly on an optically anisotropic layer, for example, a photo-alignable polymer may be unevenly distributed on the surface of the optically anisotropic layer, and the photo-alignable polymer on the surface of the optically anisotropic layer may be aligned by light irradiation, thereby imparting an alignment control force.

[0060] The features of the present invention will be explained in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0061] [Procedure] Example 1 (Preparation of Optically Anisotropic Layer C1) A polymerizable liquid crystal composition C1 having the following composition was prepared.

[0062] ------------------------------------------------ Polymerizable liquid crystal composition C1 ------------------------------------------------------------------ 100 parts by mass of mixture A of rod-shaped liquid crystal compounds shown below 4.2 parts by mass of acrylate monomer (A-400, manufactured by Shin-Nakamura Chemical Co., Ltd.) 2.0 parts by mass of polymer A shown below 0.8 parts by mass of polymer B shown below 1.9 parts by mass of compound A shown below 5.1 parts by mass of photopolymerization initiator A shown below 3.0 parts by mass of photoacid generator A shown below 374 parts by mass of methyl isobutyl ketone 94 parts by mass of ethyl propionate ------------------------------------------------

[0063] Rod-shaped liquid crystal compound mixture A (a mixture of the following compounds: liquid crystal compound (RA): liquid crystal compound (RB): liquid crystal compound (RC) in a mass ratio of 83:15:2)

[0064]

[0065] Polymer A (The numerical values ​​in the following formula indicate the content (% by mass) of each repeating unit relative to all repeating units in the polymer. The weight average molecular weight was 57,000.)

[0066]

[0067] Polymer B (In the following formula, a to c represent the content (% by mass) of each repeating unit relative to the total repeating units in the polymer, where a:b:c=37:36:27. The weight average molecular weight was 78,000.)

[0068]

[0069] ・Compound A

[0070]

[0071] Photopolymerization initiator A

[0072]

[0073] Photoacid generator A

[0074]

[0075] The prepared polymerizable liquid crystal composition C1 was applied to a cellulose polymer film (TG40, manufactured by Fujifilm Corporation) as a substrate using a #3.0 wire bar, and heated at 70°C for 2 minutes. The applied polymerizable liquid crystal composition C1 was then heated at 150 mJ / cm under conditions of an oxygen concentration of less than 100 ppm by volume. ２ Thereafter, the film was annealed at 120°C for 1 minute, and then irradiated with UV (ultraviolet) light (ultra-high pressure mercury lamp; UL750; manufactured by HOYA) at room temperature through a wire grid polarizer at 7.9 mJ / cm. ２ The optically anisotropic layer C1 was formed with a thickness of 0.7 μm by irradiating the film with light (wavelength: 313 nm) to impart an alignment function. The optically anisotropic layer C1 was a positive C plate.

[0076] (Preparation of Optically Anisotropic Layer A1) A polymerizable liquid crystal composition A1 having the following composition was prepared.

[0077] -------------------------------- Polymerizable liquid crystal composition A1------------------------------------------------ 45.4 parts by mass of rod-shaped liquid crystal compound B described below 21.8 parts by mass of rod-shaped liquid crystal compound C described below 20.0 parts by mass of rod-shaped liquid crystal compound D described below 7.8 parts by mass of the rod-shaped liquid crystal compound A described above 5.0 parts by mass of compound B described below 0.5 parts by mass of the photopolymerization initiator A described above 0.09 parts by mass of leveling agent A described below Cyclopentanone 173 parts by mass Methyl ethyl ketone 52 parts by mass Triacetin 10 parts by mass------------------------------------------------

[0078] ・Rod-shaped liquid crystal compound B

[0079]

[0080] ・Rod-shaped liquid crystal compound C

[0081]

[0082] ・Rod-shaped liquid crystal compound D

[0083]

[0084] Compound B (Me represents a methyl group)

[0085]

[0086] Leveling agent A (The numerical values ​​in the following formula indicate the content (mass%) of each repeating unit relative to all repeating units in the polymer. The weight average molecular weight was 15,000.)

[0087]

[0088] The polymerizable liquid crystal composition A1 was applied onto the previously formed optically anisotropic layer C1 using a wire bar coater #6.6 to form a composition layer. The formed composition layer was once heated to 120°C on a hot plate and then cooled to 60°C to stabilize the alignment. Thereafter, the film temperature was maintained at 60°C in a nitrogen atmosphere (oxygen concentration less than 100 volume ppm) using an ultra-high pressure mercury lamp, and the first ultraviolet irradiation (80 mJ / cm ２ ), the film temperature was kept at 120°C, and the second ultraviolet irradiation (300 mJ / cm ２ ) to fix the orientation, forming an optically anisotropic layer A1 with a thickness of 3.0 μm, and producing an optical laminate. The optically anisotropic layer A1 was a positive A plate. The angle of the in-plane slow axis with respect to the width direction of the film was 45°. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0°) when the optically anisotropic layer A1 arranged on the optically anisotropic layer C1 is observed from the optically anisotropic layer A1 side.

[0089] (Preparation of circularly polarizing plate) A polarizer with a protective film consisting of a norbornene-based resin film / polarizer P1 / TAC (triacetyl cellulose) film having a hard coat layer formed on one surface was prepared by the method described in Example 4 of JP-A No. 2021-015294. The optical laminate prepared above was attached to the TAC film side of the prepared polarizer with a protective film via the pressure-sensitive adhesive layer B described in Example 4 of JP-A No. 2021-015294, so that the optically anisotropic layer A1 side was the TAC film side of the polarizer with the protective film, and the angle between the absorption axis of the polarizer and the in-plane slow axis of the optically anisotropic layer A1 was 45 °. Then, the cellulose-based polymer film was peeled off at the interface with the optically anisotropic layer C1 to prepare a circularly polarizing plate.

[0090] (Preparation of P / S Adjustment Layer A) A silicon nitride layer (silicon nitride film) was prepared by the method described in Example 2 of JP 2011-063851 A, in which a silicon nitride layer is formed using a CVD apparatus, except that the substrate was changed to a PET film (Cosmoshine SRF manufactured by Toyobo Co., Ltd.), to obtain a PET film with a silicon nitride layer. The thickness of the silicon nitride layer was 50 nm.

[0091] Composition X was prepared by adding PMMA (15 parts by mass, weight average molecular weight: 100,000, manufactured by Sigma Aldrich, methacrylic resin) to tetrahydrofuran (85 parts by mass).

[0092] The prepared composition X was applied to the above-prepared PET film with a silicon nitride layer using a #16 wire bar and heated at 60°C for 1 minute to form a PMMA film (organic layer) with a thickness of 5 µm, thereby obtaining a PMMA film and a PET film with a silicon nitride layer.

[0093] A silicon nitride layer was produced by the method described in Example 2 of JP 2011-063851 A, in which a silicon nitride layer is formed using a CVD apparatus, except that the substrate was changed to the PET film with the PMMA film and silicon nitride layer produced above. As described above, stacking of silicon nitride layers and PMMA films was repeated to produce a P / S adjustment layer A in which four silicon nitride layers were stacked (with PMMA films between the silicon nitride layers).

[0094] (Fabrication of Organic EL Display Device) A commercially available organic EL display device (Galaxy S4, manufactured by SAMSUNG) was disassembled, and the attached polarizer and retardation film were peeled off to obtain an organic EL substrate. The P / S adjustment layer A prepared above was disposed on the obtained organic EL substrate to prepare a panel P1. At this time, the P / S adjustment layer A and the organic EL substrate were bonded together via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the PET film in the P / S adjustment layer A was in contact with the organic EL substrate. Then, the optically anisotropic layer C1 in the prepared circular polarizer was bonded to the surface of the bonded P / S adjustment layer A opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.), so that the P / S adjustment layer A was bonded to the P / S adjustment layer A side, thereby preparing the organic EL display device of Example 1.

[0095] Example 2 An organic EL display device was produced in the same manner as in Example 1, except that the optically anisotropic layer A1 was changed to an optically anisotropic layer A2 produced by the following method.

[0096] (Preparation of Optically Anisotropic Layer A2) A polymerizable liquid crystal composition A2 having the following composition was prepared.

[0097] -------------------------------- Polymerizable liquid crystal composition A2------------------------------------------------ 45.4 parts by mass of the rod-shaped liquid crystal compound B 24.1 parts by mass of the rod-shaped liquid crystal compound C 20.0 parts by mass of the rod-shaped liquid crystal compound D 5.5 parts by mass of the rod-shaped liquid crystal compound A 5.0 parts by mass of the compound B 0.5 parts by mass of the photopolymerization initiator A 0.09 parts by mass of the leveling agent A 173 parts by mass of cyclopentanone 52 parts by mass of methyl ethyl ketone 10 parts by mass of triacetin

[0098] The polymerizable liquid crystal composition A2 was applied onto the optically anisotropic layer C1 prepared above using a wire bar coater #7.0 to form a composition layer. The formed composition layer was heated to 120°C on a hot plate and then cooled to 60°C to stabilize the alignment. Thereafter, the film was irradiated with ultraviolet light (80 mJ / cm) for the first time in a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp while maintaining the film temperature at 60°C. ２ ), the film temperature was kept at 120°C and the second ultraviolet irradiation (300 mJ / cm ２ ) to fix the orientation, forming an optically anisotropic layer A2 with a thickness of 3.2 μm, and producing an optical laminate. The optically anisotropic layer A2 was a positive A plate. The angle of the in-plane slow axis with respect to the width direction of the film was 45°. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0°) when the optically anisotropic layer A2 arranged on the optically anisotropic layer C1 is observed from the optically anisotropic layer A2 side.

[0099] Example 3 A panel P2 was produced in the same manner as in Example 1, except that the P / S adjustment layer A was changed to a P / S adjustment layer B having five silicon nitride films stacked thereon (with PMMA films between the silicon nitride layers), and an organic EL display device was fabricated.

[0100] Example 4 An organic EL display device was fabricated in the same manner as in Example 2, except that the panel P1 was changed to the panel P2.

[0101] Example 5 A panel P3 was produced in the same manner as in Example 1, except that the optically anisotropic layer A1 was changed to an optically anisotropic layer A3 produced by the following method, and the P / S adjustment layer A was changed to a P / S adjustment layer C having three silicon nitride layers stacked thereon (with PMMA films between the silicon nitride layers). An organic EL display device was produced using this same method.

[0102] (Preparation of Optically Anisotropic Layer A3) A polymerizable liquid crystal composition A3 having the following composition was prepared.

[0103] -------------------------------- Polymerizable liquid crystal composition A3------------------------------------------------ 45.4 parts by mass of the rod-shaped liquid crystal compound B 18.6 parts by mass of the rod-shaped liquid crystal compound C 20.0 parts by mass of the rod-shaped liquid crystal compound D 11.0 parts by mass of the rod-shaped liquid crystal compound A 5.0 parts by mass of the compound B 0.5 parts by mass of the photopolymerization initiator A 0.09 parts by mass of the leveling agent A 173 parts by mass of cyclopentanone 52 parts by mass of methyl ethyl ketone 10 parts by mass of triacetin

[0104] Polymerizable liquid crystal composition A3 was applied onto the optically anisotropic layer C1 prepared above using a wire bar coater #6.2 to form a composition layer. The formed composition layer was heated to 120°C on a hot plate and then cooled to 60°C to stabilize the alignment. Thereafter, the film temperature was maintained at 60°C using an ultra-high pressure mercury lamp in a nitrogen atmosphere (oxygen concentration less than 100 volume ppm), and the first ultraviolet irradiation (80 mJ / cm ２ ), the film temperature was kept at 120°C and the second ultraviolet irradiation (300 mJ / cm ２ ) to fix the orientation, forming an optically anisotropic layer A3 with a thickness of 2.8 μm, and producing an optical laminate. The optically anisotropic layer A3 was a positive A plate. The angle of the in-plane slow axis with respect to the width direction of the film was 45°. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0°) when the optically anisotropic layer A3 arranged on the optically anisotropic layer C1 is observed from the optically anisotropic layer A2 side.

[0105] Example 6 An organic EL display device was fabricated in the same manner as in Example 1, except that the panel P1 was changed to the panel P3.

[0106] Example 7 An organic EL display device was fabricated in the same manner as in Example 2, except that the panel P1 was changed to the panel P3.

[0107] Example 8 An organic EL display device was produced in the same manner as in Example 5, except that the optically anisotropic layer A3 was changed to an optically anisotropic layer A4 produced by the following method.

[0108] (Preparation of Optically Anisotropic Layer A4) A polymerizable liquid crystal composition A4 having the following composition was prepared.

[0109] -------------------------------- Polymerizable liquid crystal composition A4 -------------------------------------------------- Rod-shaped liquid crystal compound B 45.4 parts by mass Rod-shaped liquid crystal compound C 27.1 parts by mass Rod-shaped liquid crystal compound D 20.0 parts by mass Rod-shaped liquid crystal compound A 2.5 parts by mass Compound B 5.0 parts by mass Photopolymerization initiator A 0.5 parts by mass Leveling agent A 0.09 parts by mass Cyclopentanone 173 parts by mass Methyl ethyl ketone 52 parts by mass Triacetin 10 parts by mass

[0110] Polymerizable liquid crystal composition A4 was applied onto the optically anisotropic layer C1 prepared above using a wire bar coater #7.4 to form a composition layer. The formed composition layer was heated to 120°C on a hot plate and then cooled to 60°C to stabilize the alignment. Thereafter, the film temperature was maintained at 60°C in a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp, and the first ultraviolet irradiation (80 mJ / cm ２ ), the film temperature was kept at 120°C, and the second ultraviolet irradiation (300 mJ / cm ２ ) to fix the orientation, forming an optically anisotropic layer A4 with a thickness of 3.4 μm, and producing an optical laminate. The optically anisotropic layer A4 was a positive A plate. The angle of the in-plane slow axis with respect to the width direction of the film was 45°. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0°) when the optically anisotropic layer A4 disposed on the optically anisotropic layer C1 is observed from the optically anisotropic layer A4 side.

[0111] Example 9 A panel P4 was produced in the same manner as in Example 5, except that the P / S adjustment layer A was changed to a P / S adjustment layer D having two silicon nitride layers stacked thereon (the layer between the silicon nitride layers was a PMMA film), and an organic EL display device was produced.

[0112] Example 10 An organic EL display device was fabricated in the same manner as in Example 1, except that the panel P1 was changed to the panel P4.

[0113] Example 11 An organic EL display device was fabricated in the same manner as in Example 8, except that the panel P3 was changed to the panel P4.

[0114] Example 12 (Preparation of photo-alignment film) Polymer C (12.0 parts by mass) and thermal acid generator A (0.6 parts by mass) were added to a mixed solution containing butyl acetate (74 parts by mass) and methyl ethyl ketone (18 parts by mass) to prepare a composition for a photo-alignment film.

[0115] Polymer C (weight average molecular weight: 40,000, the values ​​in the following formula indicate the content (mass%) of each repeating unit relative to all repeating units in the polymer.

[0116]

[0117] Thermal acid generator A

[0118]

[0119] The prepared composition for a photoalignment film was applied to a cellulose-based polymer film (TG40, manufactured by Fujifilm Corporation) using a #3.0 wire bar, and the solvent was removed by drying on a hot plate at 80°C for 5 minutes to form a photoisomerizable composition layer with a thickness of 0.5 µm. The obtained photoisomerizable composition layer was irradiated with UV (ultraviolet) light (ultra-high pressure mercury lamp; UL750; manufactured by HOYA) at 7.9 mJ / cm through a wire grid polarizer. ２ (wavelength: 313 nm) to form a photo-alignment film having a thickness of 0.5 μm.

[0120] (Preparation of Optically Anisotropic Layer A5) The polymerizable liquid crystal composition A1 prepared above was applied onto the previously formed photo-alignment film using a wire bar coater #6.6 to form a composition layer. The formed composition layer was once heated to 120°C on a hot plate and then cooled to 60°C to stabilize the alignment. Thereafter, the film temperature was maintained at 60°C using an ultra-high pressure mercury lamp in a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume), and the layer was subjected to a first ultraviolet irradiation (80 mJ / cm ２ ), the film temperature was kept at 120°C, and the second ultraviolet irradiation (300 mJ / cm ２ ) to fix the alignment, thereby forming an optically anisotropic layer A5 having a thickness of 3.0 μm. The optically anisotropic layer A5 was a positive A plate. The angle of the in-plane slow axis with respect to the width direction of the film was 45°. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0°) when the optically anisotropic layer A5 arranged on the photo-alignment film is observed from the optically anisotropic layer A5 side.

[0121] (Preparation of circularly polarizing plate) A polarizer with a protective film consisting of a norbornene-based resin film / polarizer P1 / TAC film having a hard coat layer formed on one surface was prepared by the method described in Example 4 of JP-A No. 2021-015294. The optically anisotropic layer A5 prepared above was attached to the TAC film side of the prepared polarizer with a protective film via the adhesive layer B described in Example 4 of JP-A No. 2021-015294, so that the optically anisotropic layer A5 side was the TAC film side of the polarizer with the protective film, and the angle between the absorption axis of the polarizer and the in-plane slow axis of the optically anisotropic layer A5 was 45 °. Then, the cellulose-based polymer film was peeled off at the interface with the optically anisotropic layer A5 to prepare a circularly polarizing plate.

[0122] (Fabrication of organic EL display device) The circularly polarizing plate fabricated above was attached to the P / S adjustment layer C of the panel P3 fabricated above via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer A5 faced the P / S adjustment layer C side, thereby fabricating an organic EL display device of Example 12.

[0123] Example 13 (Preparation of Optically Anisotropic Layer A6) An optically anisotropic layer A6 (thickness: 44 μm) was prepared according to the same procedure as in Example 5 of JP 2015-212368 A. The optically anisotropic layer A6 was a positive A plate. The angle of the in-plane slow axis relative to the film width direction was 45°. The angle is expressed as a positive value in the counterclockwise direction, with the film width direction being the reference (0°) when the optically anisotropic layer A6 arranged on a photo-alignment film is observed from the optically anisotropic layer A6 side.

[0124] (Preparation of circularly polarizing plate) A polarizer with a protective film consisting of a norbornene-based resin film / polarizer P1 / TAC film having a hard coat layer formed on one surface was prepared by the method described in Example 4 of JP-A No. 2021-015294. The optically anisotropic layer A6 prepared above was attached to the TAC film side of the prepared polarizer with a protective film via the pressure-sensitive adhesive layer B described in Example 4 of JP-A No. 2021-015294 so that the angle between the absorption axis of the polarizer and the in-plane slow axis of the optically anisotropic layer A6 was 45 °, thereby preparing a circularly polarizing plate.

[0125] (Fabrication of organic EL display device) The circularly polarizing plate fabricated above was attached to the P / S adjustment layer D of the panel P4 fabricated above via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer A6 was on the P / S adjustment layer D side, thereby fabricating an organic EL display device of Example 13.

[0126] Example 14 An organic EL display device was produced in the same manner as in Example 12, except that the optically anisotropic layer A5 was changed to an optically anisotropic layer A7 produced by the following method.

[0127] (Preparation of Optically Anisotropic Layer A7) A polymerizable liquid crystal composition A7 having the following composition was prepared.

[0128] ------------------------------------------------ Polymerizable liquid crystal composition A7 -------------------------------------------------- 14.0 parts by mass of rod-shaped liquid crystal compound E described below 83.0 parts by mass of rod-shaped liquid crystal compound F described below 3.0 parts by mass of rod-shaped liquid crystal compound G described below 0.5 parts by mass of the photopolymerization initiator A described above 0.09 parts by mass of the leveling agent A described above 669 parts by mass of N-methyl-2-pyrrolidone --------------------------------------------------

[0129] ・Rod-shaped liquid crystal compound E

[0130]

[0131] ・Rod-shaped liquid crystal compound F

[0132]

[0133] Rod-shaped liquid crystal compound G

[0134]

[0135] Polymerizable liquid crystal composition A7 was applied onto the photo-alignment film prepared above using a wire bar coater #12 to form a composition layer. The formed composition layer was heated to 120°C on a hot plate and then cooled to 60°C to stabilize the alignment. Thereafter, the film temperature was maintained at 60°C using an ultra-high pressure mercury lamp in a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume), and the first ultraviolet irradiation (80 mJ / cm ２ ), the film temperature was kept at 120°C, and the second ultraviolet irradiation (300 mJ / cm ２) to fix the alignment, forming an optically anisotropic layer A7 with a thickness of 2.4 μm, and producing an optical laminate. The optically anisotropic layer A7 was a positive A plate. The angle of the in-plane slow axis with respect to the width direction of the film was 45°. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0°) when the optically anisotropic layer A7 arranged on the photo-alignment film is observed from the optically anisotropic layer A7 side.

[0136] Comparative Example 1 A panel P5 was produced in the same manner as in Example 1, except that the P / S adjustment layer A was changed to a P / S adjustment layer E having six silicon nitride layers stacked thereon (with PMMA films between the silicon nitride layers), and an organic EL display device was fabricated.

[0137] Comparative Example 2 An organic EL display device was fabricated in the same manner as in Example 2, except that the panel P1 was changed to the panel P5.

[0138] Comparative Example 3 An organic EL display device was produced in the same manner as in Example 1, except that the optically anisotropic layer A1 was changed to the optically anisotropic layer A3.

[0139] Comparative Example 4 An organic EL display device was produced in the same manner as in Example 1, except that the optically anisotropic layer A1 was changed to the optically anisotropic layer A4.

[0140] [Evaluation] <P-Polarized Brightness and S-Polarized Brightness (x Value)> A polyvinyl alcohol (PVA) film having a thickness of 80 μm was dyed by immersion in an iodine aqueous solution having an iodine concentration of 0.05% by mass at 30°C for 60 seconds. The dyed PVA film was then longitudinally stretched to 10 times its original length while immersed in a boric acid aqueous solution having a boric acid concentration of 4% by mass for 60 seconds. The resulting film was then dried at 50°C for 4 minutes to obtain a linear polarizer having a thickness of 8 μm. A commercially available cellulose acylate film "TJ25" (manufactured by Fujifilm Corporation) was prepared and the cellulose acylate film was immersed in a 4.5 mol / L aqueous sodium hydroxide solution at 37°C. The sodium hydroxide on the cellulose acylate film was then thoroughly washed away with water. The resulting cellulose acylate film was then immersed in a 0.05 mol / L dilute sulfuric acid aqueous solution for 30 seconds, followed by immersion in water to thoroughly wash away the dilute sulfuric acid aqueous solution. The resulting cellulose acylate film was then dried at 70° C. for 15 seconds to prepare a polarizer protective film (thickness: 25 μm). The polarizer protective film prepared above was attached to one surface of the linear polarizer prepared above with a polyvinyl alcohol-based adhesive to prepare a polarizing plate (thickness: 33 μm) including the linear polarizer and the polarizer protective film disposed on one surface of the linear polarizer.

[0141] The polarizer with the protective film was placed in the light receiving section of a spectroradiometer SR-UL1 (manufactured by Topcon Technohouse Corporation) so that the polarizer protective film faced the light receiving section of the spectroradiometer. When measuring P-polarized light luminance, the polarizer was placed so that the absorption axis was horizontal (parallel to the light emitting surface of the prepared panel), and when measuring S-polarized light luminance, the polarizer was placed so that the absorption axis was vertical (perpendicular to the light emitting surface of the prepared panel).

[0142] For the organic EL display device fabricated as described above, the P-polarized light luminance and the S-polarized light luminance were measured by the above-mentioned measuring method, and the x value was calculated.

[0143] <In-plane retardation (y value) at each wavelength> Re(600) and Re(440) of the optically anisotropic layer in each organic EL display device were measured using AxoScan (manufactured by Axometrics) to determine the y value.

[0144] (Display Performance of Organic EL Display Device (Oblique Color)) The visibility of the organic EL display device prepared above was evaluated in a dark room. The organic EL display device was set to display white, and observed at a polar angle of 60° and at 45° intervals in an azimuth angle range of 0 to 360°, and the visibility was evaluated according to the following criteria: A: The difference in color at each azimuth angle is very slight, and is particularly excellent. B: The difference in color is visible at each azimuth angle, but is small and excellent. C: The difference in color is large at each azimuth angle, and is unacceptable.

[0145] In the table, the "Number of SiN stacks" column in the "Polarization adjustment layer" refers to the number of SiN (silicon nitride) layers in the P / S adjustment layer. Specifically, when the number of stacks is "4," the P / S adjustment layer has four SiN layers. In the "Requirements 1 to 4" columns, if the respective requirements are met, an "A" is entered, and if not, a "B" is entered.

[0146]

[0147] As shown in Table 1, it was confirmed that the organic EL display device of the present invention exhibits the desired effects. From a comparison of Examples 1 to 14, it was confirmed that when Requirements 3 and 4 are satisfied, the change in oblique color tone is smaller.

[0148] Examples 15 to 22 are also provided below.

[0149] [Implementation Procedure 2] <Example 15> (Preparation of Optical Laminate X1) The polymerizable liquid crystal composition C1 was applied to a cellulose polymer film (TG40, manufactured by Fujifilm Corporation) as a substrate using a wire bar, and heated at 70°C for 2 minutes. ２ Thereafter, the film was annealed at 120°C for 1 minute, and then irradiated with UV (ultraviolet) light (ultra-high pressure mercury lamp; UL750; manufactured by HOYA) at room temperature through a wire grid polarizer at 7.9 mJ / cm. ２ The optically anisotropic layer PC1 was formed with a thickness of 0.55 μm. The optically anisotropic layer PC1 was a positive C plate with Re(550)=0 nm and Rth(550)=−55 nm.

[0150] A polymerizable liquid crystal composition PA1 having the following composition was prepared.

[0151] -------------------------------------------------- Polymerizable liquid crystal composition PA1 ------------------------------------------------------------------ 100 parts by mass of the mixture A of the rod-like liquid crystal compounds; 0.5 parts by mass of the photopolymerization initiator A; 0.09 parts by mass of the leveling agent A; 187 parts by mass of methyl ethyl ketone.

[0152] The polymerizable liquid crystal composition PA1 was applied to the optically anisotropic layer PC1 prepared above using a wire bar coater to form a composition layer. The formed composition layer was heated to 60°C on a hot plate, and then irradiated with ultraviolet light (300 mJ / cm) in a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp while maintaining the film temperature at 60°C. ２ ) to fix the orientation, forming an optically anisotropic layer PA1 with a thickness of 0.75 μm, and an optical laminate X1 (configured in this order: cellulose polymer film / optically anisotropic layer PC1 / optically anisotropic layer PA1) was produced. The optically anisotropic layer PA1 was a positive A plate, with Re(550) = 75 nm, Rth(550) = 37.5 nm, and the angle of the in-plane slow axis with respect to the width direction of the film was 90 °. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0 °) when the optically anisotropic layer PA1 arranged on the optically anisotropic layer PC1 was observed from the optically anisotropic layer PA1 side.

[0153] (Preparation of optical laminate X2) An optical laminate X2 having an optically anisotropic layer A8 on an optically anisotropic layer C2 was prepared in the same manner as the optical laminate in Example 1, except that the thickness of the optically anisotropic layer C1 was changed to 0.4 μm.

[0154] (Preparation of circularly polarizing plate) The coated surface of the optically anisotropic layer PA1 in the optical laminate X1 prepared above (the surface opposite the optically anisotropic layer PC1) and the coated surface of the optically anisotropic layer A8 in the optical laminate X2 prepared above (the surface opposite the optically anisotropic layer C2) were bonded together with an adhesive with their widths aligned, and the cellulose-based polymer film on the optically anisotropic layer PC1 side was peeled off, thereby obtaining a laminate composed of cellulose-based polymer film / optically anisotropic layer C2 / optically anisotropic layer A8 / adhesive / optically anisotropic layer PA1 / optically anisotropic layer PC1 in this order. In the obtained laminate, the surface of the optically anisotropic layer PC1 was bonded to the TAC film side of the polarizer with the protective film shown in Example 1 using an adhesive, and then the cellulose-based polymer film on the optically anisotropic layer C2 side was peeled off to obtain a circularly polarizing plate composed of the optically anisotropic layer C2 / optically anisotropic layer A8 / adhesive / optically anisotropic layer PA1 / optically anisotropic layer PC1 / adhesive / TAC / polarizer P1 / norbornene-based resin film in this order. The in-plane slow axis of the optically anisotropic layer PA1 was at 0° to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A8 was at 45° to the absorption axis of the polarizer. The in-plane slow axis of the optically anisotropic layer PA1 is at 0° to the absorption axis of the polarizer, and only the optically anisotropic layer A8 does not change the polarization of the emitted light and substantially affects the display performance (oblique color tint) of the organic EL display device (substantially functions as a λ / 4 plate). Therefore, the Re(600) and Re(440) of the optically anisotropic layer A8 were measured, and the y value was found to be 1.31.

[0155] (Preparation of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C2 in the circularly polarizing plate prepared above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C2 was attached to the P / S adjustment layer C side, thereby preparing the organic EL display device of Example 15.

[0156] The organic EL display device of Example 15 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.31 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0157] Example 16 (Preparation of Optical Laminate X3) The polymerizable liquid crystal composition PA1 was applied with a wire bar coater onto a photo-alignment film prepared in the same manner as in Example 12 to form a composition layer. The formed composition layer was heated to 60°C on a hot plate, and then irradiated with ultraviolet light (300 mJ / cm) in a nitrogen atmosphere (oxygen concentration less than 100 ppm by volume) using an ultra-high pressure mercury lamp while maintaining the film temperature at 60°C. ２ ) to fix the alignment, forming an optically anisotropic layer PA2 with a thickness of 0.75 μm, and an optical laminate X3 (configured in this order: cellulose polymer film / photo-alignment film / optically anisotropic layer PA2) was produced. The optically anisotropic layer PA2 was a positive A plate, with Re(550) = 75 nm, Rth(550) = 37.5 nm, and the angle of the in-plane slow axis relative to the width direction of the film was 90°. The above angle is expressed as a positive value in the counterclockwise direction, with the width direction of the film as the reference (0°) when the optically anisotropic layer PA2 formed on the photo-alignment film is observed from the optically anisotropic layer PA2 side.

[0158] (Preparation of Optical Laminate X4) Except for changing the thickness of the optically anisotropic layer C1 to 1.1 μm, an optical laminate X4 having an optically anisotropic layer A9 on an optically anisotropic layer C3 was prepared in the same manner as the optical laminate in Example 1. The optically anisotropic layer C3 was a positive C plate with Re(550)=0 nm and Rth(550)=−110 nm, and the optically anisotropic layer A9 was a positive A plate with Re(550)=141 nm and Rth(550)=70.5 nm.

[0159] (Preparation of circularly polarizing plate) The coated surface of the optically anisotropic layer PA2 in the optical laminate X3 prepared above (the surface opposite the photo-alignment film) and the coated surface of the optically anisotropic layer A9 in the optical laminate X4 prepared above (the surface opposite the optically anisotropic layer C3) were bonded together with an adhesive with their widths aligned, and the cellulose-based polymer film and the photo-alignment film on the optically anisotropic layer PA2 side were peeled off to obtain a laminate composed of cellulose-based polymer film / optically anisotropic layer C3 / optically anisotropic layer A9 / adhesive / optically anisotropic layer PA2 in this order. In the obtained laminate, the surface of the optically anisotropic layer PA2 was attached to the TAC film side of the polarizer with the protective film shown in Example 1 using an adhesive, and then the cellulose-based polymer film on the optically anisotropic layer C3 side was peeled off to obtain a circularly polarizing plate configured in the following order: optically anisotropic layer C3 / optically anisotropic layer A9 / adhesive / optically anisotropic layer PA2 / adhesive / TAC / polarizer P1 / norbornene-based resin film. The in-plane slow axis of the optically anisotropic layer PA2 was at an angle of 0° to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A9 was at an angle of 45° to the absorption axis of the polarizer. The in-plane slow axis of the optically anisotropic layer PA2 is at 0° with respect to the absorption axis of the polarizer, and only the optically anisotropic layer A9 does not change the polarization of the emitted light and substantially affects the display performance (oblique color tint) of the organic EL display device (substantially functions as a λ / 4 plate). Therefore, the Re(600) and Re(440) of the optically anisotropic layer A9 were measured, and the y value was found to be 1.31.

[0160] (Fabrication of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C3 in the circularly polarizing plate fabricated above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C3 in the circularly polarizing plate was attached to the P / S adjustment layer C side, thereby fabricating the organic EL display device of Example 16.

[0161] The organic EL display device of Example 16 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.31 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0162] Example 17 (Preparation of Optical Laminate X5) An optical laminate X5 (configured in the order of cellulose polymer film / optically anisotropic layer PC1 / optically anisotropic layer PA3) having an optically anisotropic layer PC1 and an optically anisotropic layer PA3 was prepared in the same manner as the optical laminate X1 of Example 15, except that the in-plane slow axis direction (alignment axis angle of the liquid crystal compound) of the optically anisotropic layer PA1 was changed to 45° and the thickness was changed to 0.4 μm. The above angle is expressed as a positive value counterclockwise from the width direction of the film as the reference (0°) when the optically anisotropic layer PA3 disposed on the optically anisotropic layer PC1 is observed from the optically anisotropic layer PA3 side.

[0163] (Preparation of Optical Laminate X6) An optically anisotropic layer C4 was prepared in the same manner as the optically anisotropic layer C1 in Example 1, except that the thickness of the optically anisotropic layer C1 was changed to 0.55 μm. Furthermore, an optically anisotropic layer X6 having an optically anisotropic layer A10 on the optically anisotropic layer C4 was prepared in the same manner as the optical laminate in Example 1, except that the polymerizable liquid crystal composition A1 in Example 1 was changed to the following polymerizable liquid crystal composition A10, and an optically anisotropic layer A10 having a thickness of 2.9 μm was prepared.

[0164] -------------------------------- Polymerizable liquid crystal composition A10------------------------------------------------ 35.0 parts by mass of the rod-shaped liquid crystal compound B 35.0 parts by mass of the rod-shaped liquid crystal compound C 17.0 parts by mass of the rod-shaped liquid crystal compound A 13.0 parts by mass of the compound B 0.5 parts by mass of the photopolymerization initiator A 0.09 parts by mass of the leveling agent A 173 parts by mass of cyclopentanone 52 parts by mass of methyl ethyl ketone 10 parts by mass of triacetin

[0165] The optically anisotropic layer C4 was a positive C plate, with Re(550) = 0 nm and Rth(550) = -55 nm, and the optically anisotropic layer A10 was a positive A plate, with the angle of the in-plane slow axis relative to the film width direction being 45°, Re(550) = 180 nm, and Rth(550) = 90.0 nm. The above angles are expressed as positive values ​​counterclockwise from the film width direction as the reference (0°) when the optically anisotropic layer A10 disposed on the optically anisotropic layer C4 is observed from the optically anisotropic layer A10 side.

[0166] (Preparation of circularly polarizing plate) The coated surface of the optically anisotropic layer PA3 in the optical laminate X5 prepared above (the surface opposite the optically anisotropic layer PC1) and the coated surface of the optically anisotropic layer A10 in the optical laminate X6 prepared above (the surface opposite the optically anisotropic layer C4) were bonded together with an adhesive with their widths aligned, and the cellulose-based polymer film on the optically anisotropic layer PC1 side was peeled off, thereby obtaining a laminate composed of cellulose-based polymer film / optically anisotropic layer C4 / optically anisotropic layer A10 / adhesive / optically anisotropic layer PA3 / optically anisotropic layer PC1 in this order. The surface of the optically anisotropic layer PC1 was bonded to the TAC film side of the polarizer with the protective film shown in Example 1 using an adhesive, and then the cellulose-based polymer film on the optically anisotropic layer C4 side was peeled off to obtain a circular polarizer composed of the optically anisotropic layer C4 / optically anisotropic layer A10 / adhesive / optically anisotropic layer PA3 / optically anisotropic layer PC1 / adhesive / TAC / polarizer P1 / norbornene-based resin film in this order. The in-plane slow axis of the optically anisotropic layer PA3 was -45° relative to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A10 was 45° relative to the absorption axis of the polarizer. The Re(600) and Re(440) of the laminate of the optically anisotropic layer A10 and the optically anisotropic layer PA3 were measured, and the y value was found to be 1.33.

[0167] (Preparation of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C4 in the circularly polarizing plate prepared above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C4 was attached to the P / S adjustment layer C side, thereby preparing the organic EL display device of Example 17.

[0168] The organic EL display device of Example 17 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.33 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0169] Example 18 (Preparation of Optical Laminate X7) An optically anisotropic layer PA4 was formed in the same manner as the optically anisotropic layer PA2 in Example 16, except that the thickness of the optically anisotropic layer PA1 was changed to 0.4 μm and the in-plane slow axis direction (alignment axis angle of the liquid crystal compound) was changed to 45°, thereby preparing an optical laminate X7 (configured in this order: cellulose polymer film / photo-alignment film / optically anisotropic layer PA4). The angle is expressed as a positive value counterclockwise, with the film width direction as the reference (0°), when the optically anisotropic layer PA4 prepared on the photo-alignment film is observed from the optically anisotropic layer PA4 side.

[0170] (Preparation of Optical Laminate X8) An optical laminate X8 having an optically anisotropic layer A11 on an optically anisotropic layer C5 was prepared in the same manner as for the optical laminate X6 of Example 17, except that the thickness of the optically anisotropic layer C4 was changed to 1.1 μm. The optically anisotropic layer C5 was a positive C plate with Re(550)=0 nm and Rth(550)=−110 nm, and the optically anisotropic layer A11 was a positive A plate with Re(550)=180 nm and Rth(550)=90.0 nm.

[0171] (Preparation of circularly polarizing plate) The coated surface of the optically anisotropic layer PA4 in the optical laminate X7 prepared above (the surface opposite the photo-alignment film) and the coated surface of the optically anisotropic layer A11 in the optical laminate X8 prepared above (the surface opposite the optically anisotropic layer C5) were bonded together with an adhesive with their widths aligned, and the cellulose-based polymer film and the photo-alignment film on the optically anisotropic layer PA4 side were peeled off, thereby obtaining a laminate composed of cellulose-based polymer film / optically anisotropic layer C5 / optically anisotropic layer A11 / adhesive / optically anisotropic layer PA4 in this order. In the obtained laminate, the surface on the optically anisotropic layer PA4 side was bonded to the TAC film side of the polarizer with the protective film shown in Example 1 using an adhesive, and then the cellulose-based polymer film on the optically anisotropic layer C5 side was peeled off to obtain a circular polarizing plate composed of the optically anisotropic layer C5 / optically anisotropic layer A11 / adhesive / optically anisotropic layer PA4 / adhesive / TAC / polarizer P1 / norbornene-based resin film in this order. Note that the in-plane slow axis of the optically anisotropic layer PA4 was -45° relative to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A11 was 45° relative to the absorption axis of the polarizer. The Re(600) and Re(440) of the laminate of the optically anisotropic layer A11 and the optically anisotropic layer PA4 were measured, and the y value was found to be 1.33.

[0172] (Preparation of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C5 in the circularly polarizing plate prepared above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C5 was attached to the P / S adjustment layer C side, thereby preparing the organic EL display device of Example 18.

[0173] The organic EL display device of Example 18 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.33 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0174] Example 19 (Preparation of Optical Laminate X9) A polymerizable liquid crystal composition NC1 containing a discotic liquid crystal compound having the following composition was applied onto a cellulose polymer film (TG40, manufactured by Fujifilm Corporation) using a Giesser coater to form a composition layer. Thereafter, both ends of the film were held, and a cooling plate (9 ° C.) was placed on the side of the film on which the coating film was formed so that the distance from the film was 5 mm. A heater (110 ° C.) was placed on the side opposite the side on which the coating film was formed so that the distance from the film was 5 mm, and the film was dried for 90 seconds. The resulting film was then heated with warm air at 116 ° C. for 1 minute, and irradiated with a 365 nm UV-LED (ultraviolet-light emitting diode) at an irradiation dose of 150 mJ / cm while purging with nitrogen to create an atmosphere with an oxygen concentration of 100 ppm by volume or less. ２ The resulting coating film was then annealed with hot air at 1150°C for 25 seconds, and then irradiated with UV light (ultra-high pressure mercury lamp; UL750; manufactured by HOYA) at room temperature through a wire grid polarizer at 7.9 mJ / cm. ２ By irradiating the surface with 313 nm UV light, an alignment control function was imparted to the surface, forming an optically anisotropic layer NC1. The optically anisotropic layer NC1 had a film thickness of 0.75 μm. The optically anisotropic layer NC1 was a negative C plate, and had an Re(550) of 0 nm and an Rth(550) of −75 nm. The discotic liquid crystal compound had an average tilt angle of 0° on the discotic plane relative to the film surface, and was confirmed to be aligned horizontally relative to the film surface.

[0175] -------------------------------- Polymerizable liquid crystal composition NC1 ---------------------------------- 4.0 parts by mass of discotic liquid crystal compound A shown below 2.0 parts by mass of discotic liquid crystal compound B shown below 95.0 parts by mass of discotic liquid crystal compound C shown below 12.0 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate (V#360, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 3.0 parts by mass of the above photopolymerization initiator A 3.0 parts by mass of the above photoacid generator A 1.0 part by mass of the below photoalignable polymer A 208 parts by mass of methyl ethyl ketone 520 parts by mass of ethyl propionate 12 parts by mass --------------------------------

[0176] Discotic liquid crystal compound A

[0177]

[0178] Discotic liquid crystal compound B

[0179]

[0180] Discotic liquid crystal compound C

[0181]

[0182] Photoalignable polymer A (the alphabet in each repeating unit indicates the content (% by mass) of each repeating unit relative to all repeating units. From the left, the repeating units a were 37% by mass, b were 37% by mass, and c were 26% by mass. The weight-average molecular weight was 73,000.)

[0183]

[0184] Next, a polymerizable liquid crystal composition NA1 containing a discotic liquid crystal compound having the following composition was applied onto the optically anisotropic layer NC1 prepared above using a Giesser coater, and the mixture was heated with hot air at 95°C for 120 seconds. Subsequently, the resulting composition layer was irradiated with UV light (100 mJ / cm) at 95°C. ２ ) was performed to fix the alignment of the rod-shaped liquid crystal compound, thereby preparing an optically anisotropic layer NA1. The optically anisotropic layer NA1 was a negative A plate, had a thickness of 0.55 μm, and had an Re(550) of 55 nm. When the width direction of the film was set to 0° (the longitudinal direction was set to 90°), the in-plane slow axis direction (the alignment axis angle of the liquid crystal compound) was 90°.

[0185] Polymerizable liquid crystal composition NA1 ------------------------------------------------ 80 parts by mass of the above discotic liquid crystal compound A 20 parts by mass of the above discotic liquid crystal compound B 1.8 parts by mass of the alignment film interface aligning agent A described below 10.0 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate (V#360, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 5.0 parts by mass of the above photopolymerization initiator A 0.18 parts by mass of the below leveling agent B 419 parts by mass ------------------------------------------------

[0186] Alignment film interface alignment agent A

[0187]

[0188] Leveling agent B (weight average molecular weight 14,600)

[0189]

[0190] By the above procedure, an optical laminate X9 (structured in this order as cellulose polymer film / optically anisotropic layer NC1 / optically anisotropic layer NA1) having an optically anisotropic layer NA1 on an optically anisotropic layer NC1 was prepared.

[0191] (Preparation of circularly polarizing plate) The surface of the optically anisotropic layer NA1 side of the optical laminate X9 (the surface opposite to the optically anisotropic layer NC1) was bonded to the TAC film side of the polarizer with the protective film shown in Example 1 using an adhesive, and then the cellulose-based polymer film on the optically anisotropic layer NC1 side was peeled off to expose the optically anisotropic layer NC1. Subsequently, the coated surface of the optically anisotropic layer A8 (the surface opposite to the optically anisotropic layer C2) in the optical laminate X2 prepared in Example 15 was bonded to the exposed surface of the optically anisotropic layer NC1 with an adhesive, with the width direction aligned, and the cellulose-based polymer film on the optically anisotropic layer C2 side was peeled off to obtain a circularly polarizing plate configured in this order: optically anisotropic layer C2 / optically anisotropic layer A8 / adhesive / optically anisotropic layer NC1 / optically anisotropic layer NA1 / adhesive / TAC / polarizer P1 / norbornene-based resin film. The in-plane slow axis of the optically anisotropic layer NA1 was at 90° to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A8 was at 45° to the absorption axis of the polarizer. Since the in-plane slow axis of the optically anisotropic layer NA1 was at 90° to the absorption axis of the polarizer, and only the optically anisotropic layer A8 does not change the polarization of the emitted light and substantially affects the display performance (oblique color) of the organic EL display device (substantially functions as a λ / 4 plate), the Re(600) and Re(440) of the optically anisotropic layer A8 were measured, and the y value was found to be 1.31.

[0192] (Preparation of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C2 in the circularly polarizing plate prepared above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C2 was attached to the P / S adjustment layer C side, thereby preparing the organic EL display device of Example 19.

[0193] The organic EL display device of Example 19 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.31 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0194] Example 20 (Preparation of Optical Laminate X10) A cellulose-based polymer film (TG40, manufactured by Fujifilm Corporation) was passed through a dielectric heating roll at a temperature of 60°C to raise the film surface temperature to 40°C, and then an alkaline solution having the composition shown below was applied to the band surface of the film using a bar coater in an amount of 14 mL / m ２ The coated substrate was then transported for 10 seconds under a steam-type far-infrared heater manufactured by Noritake Co., Ltd. that had been heated to 110° C. Subsequently, pure water was applied at a rate of 3 mL / m using the same bar coater. ２ Next, the film was washed with water using a fountain coater and then drained with an air knife three times, and then transported to a drying zone at 70° C. for 10 seconds to dry, thereby preparing an alkali-saponified cellulose acylate film.

[0195] Alkaline solution ------------------------------------------------ Potassium hydroxide 4.7 parts by mass Water 15.8 parts by mass Isopropanol 63.7 parts by mass Surfactant: C １４ H ２９ O (CH ２ CH ２ O) ２０ H 1.0 mass part Propylene glycol 14.8 mass parts

[0196] (Formation of Orientation Film) An orientation film coating solution 1 having the following composition was continuously applied to the alkali saponified surface of the cellulose acylate film using a wire bar #14. The resulting coating film was then dried with hot air at 60°C for 60 seconds and then with hot air at 100°C for 120 seconds to obtain an orientation film.

[0197] ------------------------------------------------------------------ Alignment film coating solution 1 -------------------------------------------------- Polyvinyl alcohol (PVA-203, manufactured by Kuraray) 28 parts by mass Citric acid ester (AS3, manufactured by Sankyo Chemical Co., Ltd.) 1.2 parts by mass Glutaraldehyde 2.8 parts by mass Water 699 parts by mass Methanol 226 parts by mass ------------------------------------------------------------------

[0198] The alignment film thus prepared was continuously subjected to a rubbing treatment, in which the longitudinal direction of the long film (cellulose acylate film) was parallel to the conveying direction, and the angle between the longitudinal direction of the film (conveying direction) and the rotation axis of the rubbing roller was 90°.

[0199] A polymerizable liquid crystal composition NA2 containing a discotic liquid crystal compound of the following composition was applied onto the rubbed alignment film using a Giesser coater to form a composition layer. The resulting composition layer was then heated with hot air at 110°C for 2 minutes to dry the solvent and ripen the alignment of the discotic liquid crystal compound. Subsequently, the resulting composition layer was irradiated with UV light (500 mJ / cm) at 80°C. ２ ) was performed to fix the alignment of the discotic liquid crystal compound, forming an optically anisotropic layer NA2, and an optical laminate X10 (configured in this order: cellulose polymer film / alignment film / optically anisotropic layer NA2) was produced. The optically anisotropic layer NA2 was a negative A plate, and the thickness of the optically anisotropic layer NA2 was 0.55 μm and the Re(550) was 55 nm. When the width direction of the film was 0° (the longitudinal direction was 90°), the in-plane slow axis direction (the alignment axis angle of the liquid crystal compound) was 90°.

[0200] Polymerizable liquid crystal composition NA2 ---------------------------------------------------------------- 80 parts by mass of the discotic liquid crystal compound A 20 parts by mass of the discotic liquid crystal compound B 0.55 parts by mass of the alignment film interface aligning agent A 0.1 parts by mass of the leveling agent B 10 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate (V#360, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 3.0 parts by mass of photopolymerization initiator (Irgacure 907, manufactured by BASF) 200 parts by mass of methyl ethyl ketone ----------------------------------------------------------------

[0201] (Preparation of Optical Laminate X11) Except for changing the thickness of the optically anisotropic layer C1 to 0.15 μm, an optical laminate X11 having an optically anisotropic layer A12 on an optically anisotropic layer C6 was prepared in the same manner as the optical laminate in Example 1. The optically anisotropic layer C6 was a positive C plate with Re(550)=0 nm and Rth(550)=−15 nm, and the optically anisotropic layer A12 was a positive A plate with Re(550)=141 nm and Rth(550)=70.5 nm.

[0202] (Preparation of Circularly Polarizing Plate) The surface of the optically anisotropic layer NA2 side of the optical laminate X10 (the surface opposite to the alignment film) was attached to the TAC film side of the polarizer with a protective film shown in Example 1 using a pressure-sensitive adhesive, and then the cellulose-based polymer film and alignment film on the optically anisotropic layer NA2 side were peeled off. The coated surface of the optically anisotropic layer A12 in the optical laminate X11 prepared above (the surface opposite to the optically anisotropic layer C6) was attached to the exposed surface of the optically anisotropic layer NA2 with the width direction aligned using a pressure-sensitive adhesive, and the cellulose-based polymer film on the optically anisotropic layer C6 side was peeled off to obtain a circularly polarizing plate configured in this order: optically anisotropic layer C6 / optically anisotropic layer A12 / adhesive / optically anisotropic layer NA2 / adhesive / TAC / polarizer P1 / norbornene-based resin film. The in-plane slow axis of the optically anisotropic layer NA2 was at an angle of 90° to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A12 was at an angle of 45° to the absorption axis of the polarizer. Since the in-plane slow axis of the optically anisotropic layer NA2 was at an angle of 90° to the absorption axis of the polarizer, and only the optically anisotropic layer A12 does not change the polarization of the emitted light and substantially affects the display performance (oblique color) of the organic EL display device (substantially functions as a λ / 4 plate), the Re(600) and Re(440) of the optically anisotropic layer A12 were measured, and the y value was found to be 1.31.

[0203] (Preparation of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C6 in the circularly polarizing plate prepared above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C6 in the circularly polarizing plate was attached to the P / S adjustment layer C side, thereby preparing the organic EL display device of Example 20.

[0204] The organic EL display device of Example 20 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.31 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0205] Example 21 (Preparation of Optical Laminate X12) An optical laminate X12 (configuration in the order of cellulose polymer film / optically anisotropic layer NC2 / optically anisotropic layer NA3) having an optically anisotropic layer NA3 on an optically anisotropic layer NC2 was prepared in the same manner as the optically anisotropic layer X9 of Example 19, except that the thickness of the optically anisotropic layer NC1 and the in-plane slow axis direction (alignment axis angle of the liquid crystal compound) and thickness of the optically anisotropic layer NA1 were changed as follows. The optically anisotropic layer NC2 was a negative C plate, had a thickness of 0.4 μm, Re(550) was 0 nm, and Rth(550) was 40 nm. The optically anisotropic layer NA3 was a negative A plate, had a thickness of 0.45 μm, and Re(550) was 45 nm. When the width direction of the film was set to 0° (the longitudinal direction was set to 90°), the in-plane slow axis direction (the orientation axis angle of the liquid crystal compound) was −45°.

[0206] (Preparation of Optical Laminate X13) Except for changing the thickness of the optically anisotropic layer C1 to 1.1 μm and the thickness of the optically anisotropic layer A1 to 3.0 μm, an optical laminate X13 having an optically anisotropic layer A13 on an optically anisotropic layer C7 was prepared in the same manner as the optical laminate of Example 1. The optically anisotropic layer C7 was a positive C plate with Re(550)=0 nm and Rth(550)=−110 nm, and the optically anisotropic layer A13 was a positive A plate with Re(550)=185 nm and Rth(550)=92.5 nm.

[0207] (Preparation of circularly polarizing plate) The same method as in Example 19 was used, except that the optical laminate X12 was used instead of the optical laminate X9 and the optical laminate X13 was used instead of the optical laminate X2. A circularly polarizing plate composed of the following sequence was obtained: optically anisotropic layer C7 / optically anisotropic layer A13 / pressure-sensitive adhesive / optically anisotropic layer NC2 / optically anisotropic layer NA3 / pressure-sensitive adhesive / TAC / polarizer P1 / norbornene-based resin film. The in-plane slow axis of the optically anisotropic layer NA3 was -45° relative to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A13 was 45° relative to the absorption axis of the polarizer. The Re (600) and Re (440) of the laminate of the optically anisotropic layer A13 and the optically anisotropic layer NA3 were measured, and the y value was found to be 1.30.

[0208] (Fabrication of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C7 in the circularly polarizing plate fabricated above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C7 was attached to the P / S adjustment layer C side, thereby fabricating the organic EL display device of Example 21.

[0209] The organic EL display device of Example 21 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.30 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0210] Example 22 (Preparation of Optical Laminate X14) An optical laminate X14 (configured in this order of cellulose polymer film / alignment film / optically anisotropic layer NA4) having an optically anisotropic layer NA4 was prepared in the same manner as the optical laminate X10 of Example 20, except that the in-plane slow axis direction (alignment axis angle of the liquid crystal compound) and thickness of the optically anisotropic layer NA2 were changed as follows. The optically anisotropic layer NA4 was a negative A plate, had a thickness of 0.45 μm, and had an Re(550) of 45 nm. When the width direction of the film was 0° (the longitudinal direction was 90°), the in-plane slow axis direction (alignment axis angle of the liquid crystal compound) was −45°.

[0211] (Preparation of Optical Laminate X15) Except for changing the thickness of the optically anisotropic layer C1 to 0.80 μm and the thickness of the optically anisotropic layer A1 to 3.0 μm, an optical laminate X15 having an optically anisotropic layer A14 on the optically anisotropic layer C8 was prepared in the same manner as the optical laminate in Example 1. The optically anisotropic layer C8 was a positive C plate with Re(550)=0 nm and Rth(550)=−70 nm, and the optically anisotropic layer A14 was a positive A plate with Re(550)=180 nm and Rth(550)=185 nm.

[0212] (Preparation of circularly polarizing plate) A circularly polarizing plate composed of optically anisotropic layer C8 / optically anisotropic layer A14 / pressure-sensitive adhesive / optically anisotropic layer NA4 / pressure-sensitive adhesive / TAC / polarizer P1 / norbornene-based resin film in this order was obtained in the same manner as in Example 20, except that the optical laminate X14 was used instead of the optical laminate X10 and the optical laminate X15 was used instead of the optical laminate X11. The in-plane slow axis of the optically anisotropic layer NA4 was -45° relative to the absorption axis of the polarizer, and the in-plane slow axis of the optically anisotropic layer A14 was 45° relative to the absorption axis of the polarizer. The Re(600) and Re(440) of the laminate of the optically anisotropic layer A14 and the optically anisotropic layer NA4 were measured, and the y value was found to be 1.30.

[0213] (Preparation of organic EL display device) Using panel P3 in the organic EL display device of Example 5, the optically anisotropic layer C8 in the circularly polarizing plate prepared above was attached to the surface of the P / S adjustment layer C of panel P3 opposite the PET film via an adhesive (SK2057, manufactured by Soken Chemical & Engineering Co., Ltd.) so that the optically anisotropic layer C8 was attached to the P / S adjustment layer C side, thereby preparing the organic EL display device of Example 22.

[0214] The organic EL display device of Example 22 was evaluated by the above-mentioned methods, and the results were as follows: x value: 1.54 y value: 1.30 Requirements 1 to 4: all satisfied (all rated A) Oblique color: rated A

[0215] REFERENCE SIGNS LIST 10 Organic EL display device 20 Circular polarizing plate 22 Polarizer 24 Optically anisotropic layer 30 Organic EL display element 32 Polarization adjustment layer 34 Organic EL substrate

Claims

1. An organic electroluminescent display device comprising a circular polarizing plate and an organic electroluminescent display element, The circular polarizer includes an optical anisotropic layer and a polarizer, from the organic electroluminescent display element side. For each azimuth angle rotated by 45° with respect to the direction parallel to the transmission axis of the polarizer, the ratio of the brightness of P-polarized light to the brightness of S-polarized light when the organic electroluminescent display element displays white light is determined in the direction where the polar angle with respect to the normal direction of the organic electroluminescent display element is 60°, and the arithmetic mean of the ratio of the brightness of P-polarized light to the brightness of S-polarized light at each azimuth angle is denoted as x, and the arithmetic mean x is 1.00 or greater. When y is the ratio of the in-plane retardation at a wavelength of 600 nm to the in-plane retardation at a wavelength of 440 nm of the optical anisotropic layer, An organic electroluminescent display device that satisfies requirements 1 and 2. Requirement 1: y ≤ -0.155x + 1.655 Requirement 2: y ≥ 0.170x + 0.980 The ratio of the luminance of the P-polarized light to the luminance of the S-polarized light is the arithmetic mean of the ratio of the luminance of the P-polarized light to the luminance of the S-polarized light at each wavelength in 10 nm increments within the wavelength range of 420 to 680 nm.

2. An organic electroluminescent display device according to claim 1, satisfying requirements 3 and 4. Requirement 3: y ≤ -0.240x + 1.740 Requirement 4: y≧0.260x+0.890

3. The organic electroluminescent display device according to claim 1 or 2, wherein the optical anisotropy layer is a λ / 4 plate.